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Sample records for acoustic comfort evaluation

  1. Objective and subjective evaluation of the acoustic comfort in classrooms.

    PubMed

    Zannin, Paulo Henrique Trombetta; Marcon, Carolina Reich

    2007-09-01

    The acoustic comfort of classrooms in a Brazilian public school has been evaluated through interviews with 62 teachers and 464 pupils, measurements of background noise, reverberation time, and sound insulation. Acoustic measurements have revealed the poor acoustic quality of the classrooms. Results have shown that teachers and pupils consider the noise generated and the voice of the teacher in neighboring classrooms as the main sources of annoyance inside the classroom. Acoustic simulations resulted in the suggestion of placement of perforated plywood on the ceiling, for reduction in reverberation time and increase in the acoustic comfort of the classrooms. PMID:17202022

  2. Objective and subjective evaluation of the acoustic comfort in classrooms.

    PubMed

    Zannin, Paulo Henrique Trombetta; Marcon, Carolina Reich

    2007-09-01

    The acoustic comfort of classrooms in a Brazilian public school has been evaluated through interviews with 62 teachers and 464 pupils, measurements of background noise, reverberation time, and sound insulation. Acoustic measurements have revealed the poor acoustic quality of the classrooms. Results have shown that teachers and pupils consider the noise generated and the voice of the teacher in neighboring classrooms as the main sources of annoyance inside the classroom. Acoustic simulations resulted in the suggestion of placement of perforated plywood on the ceiling, for reduction in reverberation time and increase in the acoustic comfort of the classrooms.

  3. Relationships between objective acoustic indices and acoustic comfort evaluation in nonacoustic spaces

    NASA Astrophysics Data System (ADS)

    Kang, Jian

    2001-05-01

    Much attention has been paid to acoustic spaces such as concert halls and recording studios, whereas research on nonacoustic buildings/spaces has been rather limited, especially from the viewpoint of acoustic comfort. In this research a series of case studies has been carried out on this topic, considering various spaces including shopping mall atrium spaces, library reading rooms, football stadia, swimming spaces, churches, dining spaces, as well as urban open public spaces. The studies focus on the relationships between objective acoustic indices such as sound pressure level and reverberation time and perceptions of acoustic comfort. The results show that the acoustic atmosphere is an important consideration in such spaces and the evaluation of acoustic comfort may vary considerably even if the objective acoustic indices are the same. It is suggested that current guidelines and technical regulations are insufficient in terms of acoustic design of these spaces, and the relationships established from the case studies between objective and subjective aspects would be useful for developing further design guidelines. [Work supported partly by the British Academy.

  4. Influence of social and behavioural characteristics of users on their evaluation of subjective loudness and acoustic comfort in shopping malls.

    PubMed

    Meng, Qi; Kang, Jian

    2013-01-01

    A large-scale subjective survey was conducted in six shopping malls in Harbin City, China, to determine the influence of social and behavioural characteristics of users on their evaluation of subjective loudness and acoustic comfort. The analysis of social characteristics shows that evaluation of subjective loudness is influenced by income and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Meanwhile, evaluation of acoustic comfort evaluation is influenced by income, education level, and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.60 (p<0.05 or p<0.01). The effect of gender and age on evaluation of subjective loudness and acoustic comfort is statistically insignificant. The effects of occupation are mainly caused by the differences in income and education level, in which the effects of income are greater than that of education level. In terms of behavioural characteristics, evaluation of subjective loudness is influenced by the reason for visit, frequency of visit, and length of stay, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Evaluation of acoustic comfort is influenced by the reason for visit to the site, the frequency of visit, length of stay, and also season of visit, with correlation coefficients of 0.10 to 0.30 (p<0.05 or p<0.01). In particular, users who are waiting for someone show lower evaluation of acoustic comfort, whereas users who go to shopping malls more than once a month show higher evaluation of acoustic comfort. On the contrary, the influence of the period of visit and the accompanying persons are found insignificant.

  5. Acoustical comfort of vehicles: A combination of sound and vibration

    NASA Astrophysics Data System (ADS)

    Genuit, Klaus; Schutte-Fortkamp, Brigitte; Fiebig, Andre

    2005-09-01

    As vehicles become more and more quiet, the customer's sensitivity to acoustical comfort increases. The acoustical comfort is not independent of the vibrations the driver can feel in the seat and at the steering. The passenger of a vehicle must be regarded as part of a vibro-acoustic system. Correspondingly, the subjective judgement which passengers make about their impression of levels of acoustic comfort encompasses both sound and vibration. Achievement in this field depends on obtaining knowledge about the interaction between sound and vibration and how these factors impact subjective evaluation. To save time and money prediction tools for the estimation of sound and vibration contributions into the vehicle cabin are very important in order to simulate the final comfort with respect to sound and vibration. Based on the binaural transfer path analysis in combination with the binaural transfer path synthesis a sound and vibration reproduction in a so-called SoundCar can be realized with a very good simulation of a real situation of a car. First research tests completed for the European research project OBELICS (Objective Evaluation of Interior Car Sound) have shown that the use of SoundCar may result in more reliable sound characteristic and quality evaluation.

  6. Occupant thermal comfort evaluation

    NASA Astrophysics Data System (ADS)

    Ghiardi, Gena L.

    1999-03-01

    Throughout the automotive industry there has been an increasing concern and focus on the thermal comfort of occupants. Manufacturers are continuously striving to improve heating and air conditioning performance to comply with expanding customer needs. To optimize these systems, the technology to acquire data must also be enhanced. In this evaluation, the standard use of isolated thermocouple location technology is compared to utilizing infrared thermal vision in an air conditioning performance assessment. Infrared data on an actual occupant is correlated to breath and air conditioning output temperatures measured by positioned thermocouples. The use of infrared thermal vision highlights various areas of comfort and discomfort experienced by the occupant. The evaluation involves utilizing an infrared thermal vision camera to film an occupant in the vehicle as the following test procedure is run. The vehicle is soaked in full sun load until the interior temperature reaches a minimum of 150 degrees F (65.6 degrees Celsius). The occupant enters the vehicle and takes an initial temperature reading. The air conditioning is turned on to full cold, full fan speed, and recirculation mode. While being filmed, the driver drives for sixty minutes at 30 miles per hour (48.3 kph). The thermocouples acquire data in one minute intervals while the infrared camera films the cooling process of the occupant.

  7. Effects of individual sound sources on the subjective loudness and acoustic comfort in underground shopping streets.

    PubMed

    Kang, Jian; Meng, Qi; Jin, Hong

    2012-10-01

    Previous studies have demonstrated that human evaluation of subjective loudness and acoustic comfort depends on a series of factors in a particular situation rather than only on sound pressure levels. In the present study, a large-scale subjective survey has been undertaken on underground shopping streets in Harbin, China, to determine how individual sound sources influence subjective loudness and acoustic comfort evaluation. Based on the analysis of case study results, it has been shown that all individual sound sources can increase subjective loudness to a certain degree. However, their levels of influence on acoustic comfort are different. Background music and the public address system can increase acoustic comfort, with a mean difference of 0.18 to 0.32 and 0.21 to 0.27, respectively, where a five-point bipolar category scale is used. Music from shops and vendor shouts can decrease acoustic comfort, with a mean difference of -0.11 to -0.38 and -0.39 to -0.62, respectively. The feasibility of improving acoustic comfort by changing certain sound sources is thus demonstrated.

  8. Visual comfort evaluated by opponent colors

    NASA Astrophysics Data System (ADS)

    Sagawa, Ken

    2002-06-01

    This study aimed to evaluate psychological impression of visual comfort when we see an image of ordinary colored scene presented in a color display. Effects of opponent colors, i.e. red, green, yellow and blue component, on the subjective judgement on visual comfort to the image were investigated. Three kinds of psychological experiment were designed to see the effects and the results indicated that the red/green opponent color component was more affecting than the yellow-blue one, and red color in particular was the most affecting factor on visual comfort.

  9. [Nasal comfort and Cottle septoplasty. Prospective acoustic rhinometry study apropos of 102 cases].

    PubMed

    Truilhé, Y; Stoll, D

    2000-01-01

    Between june 1997 and september 1998, we have prospectively studied a cohort of 102 patients who were referred to ENT consultation. All patients suffered a septal deviation and a syndrome that we call "morphological". All were operated on following the Cottle's septoplasty technique. At pre- and postoperative consultation, patients were asked to answer a questionnaire and a functional evaluation of the nasal air flow was assessed by acoustic rhinometry. We have described a nasal comfort grading that we compare with the objective results as assessed by acoustic rhinometry. Our study did not permit us to find any correlation between nasal comfort and minimal cross sectional area (MCA). But evaluation of the MCA was disturbed by several methodological artifacts. A statistical correlation between the nasal comfort grading and nasal volume in the side of the septal deviation was found. The acoustic rhinometry evaluation elicited two essential observations: the first is the increase of nasal fossae volume of 30% (and, at least, 26% of the MCA). The other is a relative decrease of 45% of nasal mucosa congestion. This study shows that the nasal septum has an essential function in the pathogenesis of the so-called "morphological" functional syndrome. The morphological correction obtained by the Cottle's septoplasty acts upon the nasal vasomotricity in decreasing nasal mucosa congestion and avoid a surgical reduction of the inferior turbinate.

  10. [Thermal comfort in perioperatory risk's evaluation].

    PubMed

    Masia, M D; Dettori, M; Liperi, G; Deriu, G M; Posadino, S; Maida, G; Mura, I

    2009-01-01

    Studies till now conducted about operating rooms' microclimate have been focused mainly on operators' thermal comfort, considering that uneasiness conditions may compromise their working performance. In last years, nevertheless, the anesthesiologic community recalled attention on patients' risks determined by perioperatory variations of normothermia, underlining the necessity of orientating studies to individuate microclimate characteristics act to guarantee thermal comfort of the patient too. Looking at these considerations, a study has been conducted in the operating rooms of the hospital-university Firm and the n.1 USL of Sassari, finalized, on one hand, to determinate microclimate characteristics of the operating blocks and to evaluate operators' and patients' thermal comfort, on the other to individuate, through a software simulation, microclimate conditions that ensure contemporarily thermal comfort for both the categories. Results confirm the existence of a thermal "gap" among operators and patients, these last constantly submitted to "cold-stress", sometimes very accentuated. So, we underline microclimate's importance in operating rooms, because there are particular situations that can condition perioperatory risks. Moreover it can be useful to integrate risk's classes of the American Society of Anestesiology (ASA) with a score attributed to the PMV/PPD variation, reaching more real operatory risk indicators. PMID:19798902

  11. Evaluation of Peer Comforting Strategies by Children and Adolescents

    ERIC Educational Resources Information Center

    Clark, Ruth Anne; MacGeorge, Erina L.; Robinson, Lakesha

    2008-01-01

    Despite the importance of social support across the lifespan and extensive research on supportive communication between adults, little is known about how children or adolescents respond to the comforting efforts of their peers. The current study was designed to examine how 5th, 7th, and 9th graders evaluate six peer comforting strategies…

  12. Analytical and experimental evaluation of proposed ride comfort criteria

    NASA Technical Reports Server (NTRS)

    Vinje, E. W.

    1972-01-01

    An exploratory study was conducted to evaluate the effectiveness of indices proposed by different investigators to relate vehicle vibrations to passenger comfort. The indices considered included criteria for sinusoidal vibrations, unweighted and weighted amplitude exceedance counts, the integral of the unweighted and weighted power spectral density and absorbed power. These functions were initially examined analytically to determine the manner in which they each weighed vibration amplitude and frequency. Similarities among them are noted. Index values were then computed from measured vibrations and compared with the associated comfort ratings. The data for these comparisons were obtained from ride comfort evaluations of passenger trains.

  13. Data on the acoustic comfort of passengers in railroad cars and soundproofing recommendations

    NASA Technical Reports Server (NTRS)

    Tomescu, C.; Vrasti, R.

    1974-01-01

    Acoustic passenger comfort in railroad cars is represented by the following values: Total noise level in db, octave sound spectrum in db, and indices of intelligibility. The noise level perceived inside the car results from two components: one due to the penetration of air noise, and another due to the transmission of vibrations through solids. Measurement results show the necessity of improving bogie and bogie-body connections, intensification of soundproofing of the floor, adaption of windows with double panes, etc.

  14. Comfort evaluation of maternity support garments in a wear trial.

    PubMed

    Ho, S S; Yu, W; Lao, T T; Chow, D H K; Chung, J W; Li, Y

    2008-09-01

    This study aims to evaluate the wear comfort of eight commercially available maternity support garments. The thermophysiological, sensory/tactile and movement comfort were assessed in a wear trial using a 19-item questionnaire. Fourteen pregnant Chinese women aged 32.3 +/- 4.2 years were recruited from a local obstetric clinic. The results show that the tested garments generally provided greater sensory comfort than thermophysiological comfort. The thermophysiological comfort was mainly influenced by the fibre contents and breathability. Significant linear relationships were found between material appearance and hand feel (r = 0.86, p < 0.001), and between non-itchiness and no red mark (r = 0.78, p < 0.001). Movement comfort was influenced by the garment type and style features. Overall, the soft, good-fit, cotton/elastane maternity brief was perceived as the best product. The findings of comfort needs in pregnant women and the effects of various garment attributes would be helpful for the development of maternity support garment design criteria that are required to satisfy critical ergonomic needs. Low back pain during pregnancy is a common and significant health problem. A maternity support garment is regarded as a convenient and safe device to stabilise the lumbar spine so as to relieve pain. However, patient compliance is likely to be affected by discomfort and inconvenience. The results of this study provide guidance for the optimal design of maternity support clothing.

  15. Bringing comfort to the masses: a novel evaluation of comfort agent solution properties.

    PubMed

    White, Charles J; Thomas, Calvin R; Byrne, Mark E

    2014-04-01

    Ocular comfort agents are molecules that relieve ocular discomfort by augmenting characteristics of the tear film to stabilize and retain tear volume and lubricate the ocular surface. While a number of clinical comparisons between ocular comfort agent solutions are available, very little work has been done correlating the properties of specific comfort agents (species, molecular weight, and water retention) and solution properties (concentration, viscosity, zero shear viscosity, and surface tension) to the performance and effectiveness of comfort agent solutions. In this work, comfort-promoting properties related strongly to comfort agent concentration and molecular weight, the first objective demonstration of this relationship across diverse comfort agent species and molecular weights. The comfort agents with the greatest comfort property contributions (independent of specific molecular weight and concentration considerations) were hyaluronic acid (HA), hydroxypropyl methylcellulose (HPMC), and carboxymethylcellulose (CMC), respectively. The observed, empirical relationships between comfort property contribution and comfort agent species, solution properties, comfort agent molecular weight, and solution concentration was used to develop novel comfort agent index values. The comfort agent index values provided much insight and understanding into the results of experimental studies and/or clinical trials and offer potential resolution to numerous conflicting reports within the literature by accounting for the difference in comfort agent performance due to molecular weight and concentration of comfort agents. The index values provide the first objective, experimental validation and explanation of numerous general trends suggested by clinical data.

  16. Ductless Mini-Split Heat Pump Comfort Evaluation

    SciTech Connect

    Roth, K.; Sehgal, N.; Akers, C.

    2013-03-01

    Field tests were conducted in two homes in Austin, TX to evaluate the comfort performance of ductless mini-split heat pumps (DMSHPs), measuring temperature and relative humidity measurements in four rooms in each home before and after retrofitting a central HVAC system with DMSHPs.

  17. Ductless Mini-Split Heat Pump Comfort Evaluation

    SciTech Connect

    Roth, K.; Sehgal, N.; Akers, C.

    2013-03-01

    Field tests were conducted in two homes in Austin, TX, to evaluate the comfort performance of ductless minisplit heat pumps (DMSHPs), measuring temperature and relative humidity measurements in four rooms in each home before and after retrofitting a central HVAC system with DMSHPs.

  18. The need for standards and codes to ensure an acoustically comfortable environment in multifamily housing buildings in Mexico City

    NASA Astrophysics Data System (ADS)

    Kotasek Gonzalez, Eduardo; Rodriguez Manzo, Fausto

    2002-11-01

    It is clear that almost all kinds of buildings require protection against noise and undesirable sounds, however, there are some countries where this is not yet regulated, such is the case of Mexico. Mexico City, the biggest city in the world could also be the noisiest. This is a problem which is today being debated; in fact there is no doubt that this has an important influence on the acoustic comfort conditions of dwellings, besides the habits and culture of the inhabitants, which are very different from those in the Anglo-Saxon countries. These are all details that must be taken into account in the design of an acoustic comfort standard for buildings in cities like Mexico. In this paper we deal with this problem and it suggests some recommendations to consider in a proposed acoustic comfort standard or code to be applied in the design of multifamily housing buildings in Mexico City.

  19. Acoustical and noise redesign considerations when trying to increase patient privacy while ensuring comfort

    NASA Astrophysics Data System (ADS)

    Klavetter, Eric

    2005-09-01

    An internal assessment was undertaken to understand the flow of patients to ensure comfort and privacy during their health care experience at Mayo Clinic. A number of different prototypes, work flows, and methodologies were utilized and assessed to determine the ``best experience for our patients.'' A number of prototypes ranging from self-check in to personal pagers were assessed along with creating environments that introduced ``passive distractions'' for acoustical and noise management, which can range from fireplaces, to coffee shops to playgrounds to ``tech corridors.'' While a number of these designs are currently being piloted, the over-reaching goal is to make the patient experience ``like no other'' when receiving their care at Mayo Clinic.

  20. [ACOUSTIC FEATURES OF VOCALIZATIONS, REFLECTING THE DISCOMFORT AND COMFORT STATE OF INFANTS AGED THREE AND SIX MONTHS].

    PubMed

    Pavlikova, M I; Makarov, A K; Lyakso, E E

    2015-08-01

    The paper presented the possibility of recognition by adult the comfort and discomfort state of 3 and 6 months old infant's on the base of their vocalizations. The acoustic features of the vocalizations that are important for the recognition of the infant state of the characteristics of voice was described. It is shown that discomfort vocalizations differ from comfort ones on the basis of the average and maximum values of pitch, pitch values in the central and final part of the vocalization. A mathematical model is proposed and described a classification function signal of discomfort and comfort. Was found that the vocalizations of infants attributable adults with a probability of 0.75 and above the categories of comfort and discomfort with high reliability are recognized by the mathematical model based on a classification function.

  1. Acoustical evaluation of preschool classrooms

    NASA Astrophysics Data System (ADS)

    Yang, Wonyoung; Hodgson, Murray

    2003-10-01

    An investigation was made of the acoustical environments in the Berwick Preschool, Vancouver, in response to complaints by the teachers. Reverberation times (RT), background noise levels (BNL), and in-class sound levels (Leq) were measured for acoustical evaluation in the classrooms. With respect to the measured RT and BNL, none of the classrooms in the preschool were acceptable according to the criteria relevant to this study. A questionnaire was administered to the teachers to assess their subjective responses to the acoustical and nonacoustical environments of the classrooms. Teachers agreed that the nonacoustical environments in the classrooms were fair, but that the acoustical environments had problems. Eight different classroom configurations were simulated to improve the acoustical environments, using the CATT room acoustical simulation program. When the surface absorption was increased, both the RT and speech levels decreased. RASTI was dependent on the volumes of the classrooms when the background noise levels were high; however, it depended on the total absorption of the classrooms when the background noise levels were low. Ceiling heights are critical as well. It is recommended that decreasing the volume of the classrooms is effective. Sound absorptive materials should be added to the walls or ceiling.

  2. The relationship between electrical acoustic reflex thresholds and behavioral comfort levels in children and adult cochlear implant patients.

    PubMed

    Spivak, L G; Chute, P M

    1994-04-01

    The accuracy with which behavioral comfort levels could be predicted by the electrically elicited acoustic reflex threshold (EART) was examined in 35 Nucleus Cochlear Implant patients (16 adults and 19 children). EARTs were obtained by stimulating bipolar pairs of electrodes through the Nucleus Diagnostic Programming System and monitoring the change in middle ear admittance in the ear contralateral to the implanted ear. EARTs were successfully elicited in 24 patients. EARTs differed from behavioral comfort levels by a mean of 19.4 stimulus level units for adults and 9.6 stimulus level units for children. While EARTs were found to be acceptably close to behavioral comfort levels in four adults and eight children, EARTs significantly overestimated or underestimated comfort levels in the rest. The results of this study suggested that while the EART does not accurately predict comfort levels in all cases, it may provide valuable information regarding levels which should not be exceeded when programming the cochlear implant. Cautious use of information available from the EART may prove useful for programming the cochlear implant in children or adults who are unable to make reliable psychophysical judgments.

  3. Frequency weighting filter design for automotive ride comfort evaluation

    NASA Astrophysics Data System (ADS)

    Du, Feng

    2016-07-01

    Few study gives guidance to design weighting filters according to the frequency weighting factors, and the additional evaluation method of automotive ride comfort is not made good use of in some countries. Based on the regularities of the weighting factors, a method is proposed and the vertical and horizontal weighting filters are developed. The whole frequency range is divided several times into two parts with respective regularity. For each division, a parallel filter constituted by a low- and a high-pass filter with the same cutoff frequency and the quality factor is utilized to achieve section factors. The cascading of these parallel filters obtains entire factors. These filters own a high order. But, low order filters are preferred in some applications. The bilinear transformation method and the least P-norm optimal infinite impulse response(IIR) filter design method are employed to develop low order filters to approximate the weightings in the standard. In addition, with the window method, the linear phase finite impulse response(FIR) filter is designed to keep the signal from distorting and to obtain the staircase weighting. For the same case, the traditional method produces 0.330 7 m • s-2 weighted root mean square(r.m.s.) acceleration and the filtering method gives 0.311 9 m • s-2 r.m.s. The fourth order filter for approximation of vertical weighting obtains 0.313 9 m • s-2 r.m.s. Crest factors of the acceleration signal weighted by the weighting filter and the fourth order filter are 3.002 7 and 3.011 1, respectively. This paper proposes several methods to design frequency weighting filters for automotive ride comfort evaluation, and these developed weighting filters are effective.

  4. The Digital Divide in Classrooms: Teacher Technology Comfort and Evaluations

    ERIC Educational Resources Information Center

    Dornisch, Michele

    2013-01-01

    A disconnect exists between students' comfort with using technology for learning and teachers' comfort in using technology for teaching. Students report the desire for more engaging technology-based assignments. Teachers cite multiple reasons for their hesitancy to use technology in their teaching. The current study investigates whether…

  5. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  6. Objective evaluation method of steering comfort based on movement quality evaluation of driver steering maneuver

    NASA Astrophysics Data System (ADS)

    Yang, Yiyong; Liu, Yahui; Wang, Man; Ji, Run; Ji, Xuewu

    2014-09-01

    The existing research of steering comfort mainly focuses on the subjective evaluation, aiming at designing and optimizing the steering system. In the development of steering system, especially the evaluation of steering comfort, the objective evaluation methods considered the kinematic characteristics of driver steering maneuver are not proposed, which means that the objective evaluation of steering cannot be conducted with the evaluation of kinematic characteristics of driver in steering maneuver. In order to propose the objective evaluation methods of steering comfort, the evaluation of steering movement quality of driver is developed on the basis of the study of the kinematic characteristics of steering maneuver. First, the steering motion trajectories of the driver in both comfortable and certain extreme uncomfortable operation conditions are detected using the Vicon motion capture system. The operation conditions are under the restrictions of the vertical height and horizontal distance between steering wheel center and the H-point of driver, and the steering resisting torque else. Next, the movement quality evaluation of driver steering maneuver is assessed using twelve kinds of evaluation indices based on the kinematic analyses of the steering motion trajectories to propose an objective evaluation method. Finally, an integrated discomfort index of steering maneuver is proposed on the basis of the regression analysis of subjective evaluation rating and the movement quality evaluation indices, including the Jerk, Discomfort and Joint Torque indices. The test results show that the proposed integrated discomfort index gives a good fitting with the subjective evaluation of discomfort, which means it can be used to evaluate or predict the discomfort level of steering maneuver. This paper proposes an objective evaluation method of steering comfort based on the movement quality evaluation of driver steering maneuver.

  7. Ride quality evaluation. I. [aircraft passenger comfort assessment

    NASA Technical Reports Server (NTRS)

    Richards, L. G.; Jacobson, I. D.

    1975-01-01

    As part of a larger effort to assess passenger comfort in aircraft, two questionnaires were administered: one to ground-based respondents, the other to passengers in flight. Respondents indicated the importance of various factors influencing their satisfaction with a trip, the perceived importance of various physical factors in determining their level of comfort, and the ease of time spent performing activities in flight. The in-flight sample also provided a rating of their level of comfort and of their willingness to fly again. Comfort ratings were examined in relation to (1) type of respondent, (2) type of aircraft, (3) characteristics of the passengers, (4) ease of performing activities, and (5) willingness to fly again.

  8. Ride quality evaluation 1: Questionnaire studies of airline passenger comfort

    NASA Technical Reports Server (NTRS)

    Richards, L. G.; Jacobson, I. D.

    1974-01-01

    As part of a larger effort to assess passenger comfort in aircraft, two questionnaires were administered: one to ground-based respondents; the other to passengers in flight. Respondents indicated the importance of various factors influencing their satisfaction with a trip, the perceived importance of various physical factors in determining their level of comfort, and the ease of time spent performing activities in flight. The in-flight sample also provided a rating of their level of comfort and of their willingness to fly again. Comfort ratings were examined in relation to (1) type of respondent, (2) type of aircraft, (3) characteristics of the passengers, (4) ease of performing activities, and (5) willingness to fly again.

  9. COMFORT: evaluating a new communication curriculum with nurse leaders.

    PubMed

    Goldsmith, Joy; Wittenberg-Lyles, Elaine

    2013-01-01

    Nursing faculty face increasing instructional demands to keep pace with mounting knowledge and competency requirements for student nurses. In the context of nursing practice, tasks and time pressures detract from the high skill and aptitude expectation of communication. The communication, orientation and opportunity, mindful presence, family, openings, relating, and team (COMFORT) curriculum, an acronym that represents 7 basic nursing communication principles, has been introduced into the communication module of the End-of-Life Nursing Education Consortium, which currently provides the only standardized undergraduate and graduate nurse training in hospice and palliative care. This study examines the potential efficacy of the COMFORT curriculum for everyday communication challenges experienced by members of the Georgia Organization of Nurse Leaders. Participants were prompted to describe communication barriers and then apply an aspect of the COMFORT curriculum to this barrier. Responses revealed primary communication barriers with co-workers and patient/families. Nurses predominantly identified directly correlating components in the COMFORT framework (C-communication, F-family) as solutions to the topics described as barriers. Based on confirmation of extant literature addressing generalist nurse communication challenges, there is support for the inclusion of COMFORT across the nursing curriculum to efficiently and effectively teach communication strategies to nurses. PMID:24267933

  10. COMFORT: evaluating a new communication curriculum with nurse leaders.

    PubMed

    Goldsmith, Joy; Wittenberg-Lyles, Elaine

    2013-01-01

    Nursing faculty face increasing instructional demands to keep pace with mounting knowledge and competency requirements for student nurses. In the context of nursing practice, tasks and time pressures detract from the high skill and aptitude expectation of communication. The communication, orientation and opportunity, mindful presence, family, openings, relating, and team (COMFORT) curriculum, an acronym that represents 7 basic nursing communication principles, has been introduced into the communication module of the End-of-Life Nursing Education Consortium, which currently provides the only standardized undergraduate and graduate nurse training in hospice and palliative care. This study examines the potential efficacy of the COMFORT curriculum for everyday communication challenges experienced by members of the Georgia Organization of Nurse Leaders. Participants were prompted to describe communication barriers and then apply an aspect of the COMFORT curriculum to this barrier. Responses revealed primary communication barriers with co-workers and patient/families. Nurses predominantly identified directly correlating components in the COMFORT framework (C-communication, F-family) as solutions to the topics described as barriers. Based on confirmation of extant literature addressing generalist nurse communication challenges, there is support for the inclusion of COMFORT across the nursing curriculum to efficiently and effectively teach communication strategies to nurses.

  11. Effects of voice style, noise level, and acoustic feedback on objective and subjective voice evaluations

    PubMed Central

    Bottalico, Pasquale; Graetzer, Simone; Hunter, Eric J.

    2015-01-01

    Speakers adjust their vocal effort when communicating in different room acoustic and noise conditions and when instructed to speak at different volumes. The present paper reports on the effects of voice style, noise level, and acoustic feedback on vocal effort, evaluated as sound pressure level, and self-reported vocal fatigue, comfort, and control. Speakers increased their level in the presence of babble and when instructed to talk in a loud style, and lowered it when acoustic feedback was increased and when talking in a soft style. Self-reported responses indicated a preference for the normal style without babble noise. PMID:26723357

  12. Effects of voice style, noise level, and acoustic feedback on objective and subjective voice evaluations.

    PubMed

    Bottalico, Pasquale; Graetzer, Simone; Hunter, Eric J

    2015-12-01

    Speakers adjust their vocal effort when communicating in different room acoustic and noise conditions and when instructed to speak at different volumes. The present paper reports on the effects of voice style, noise level, and acoustic feedback on vocal effort, evaluated as sound pressure level, and self-reported vocal fatigue, comfort, and control. Speakers increased their level in the presence of babble and when instructed to talk in a loud style, and lowered it when acoustic feedback was increased and when talking in a soft style. Self-reported responses indicated a preference for the normal style without babble noise.

  13. Testing thermal comfort of trekking boots: an objective and subjective evaluation.

    PubMed

    Arezes, P M; Neves, M M; Teixeira, S F; Leão, C P; Cunha, J L

    2013-07-01

    The study of the thermal comfort of the feet when using a specific type of shoe is of paramount importance, in particular if the main goal of the study is to attend to the needs of users. The main aim of this study was to propose a test battery for thermal comfort analysis and to apply it to the analysis of trekking boots. Methodologically, the project involves both objective and subjective evaluations. An objective evaluation of the thermal properties of the fabrics used in the boots was developed and applied. In addition, the thermal comfort provided when using the boots was also assessed both subjective and objectively. The evaluation of the thermal comfort during use, which was simulated in a laboratory environment, included the measurement of the temperature and moisture of the feet. The subjective assessment was performed using a questionnaire. From the results obtained, it was possible to define an optimal combination of fabrics to apply to trekking boots by considering the provided thermal insulation, air permeability and wicking. The results also revealed that the subjective perception of thermal comfort appears to be more related to the increase in temperature of the feet than to the moisture retention inside the boot. Although the evaluation of knits used in the boots indicated that a particular combination of fibres was optimal for use in the inner layer, the subjective and objective evaluation of thermal comfort revealed that the evaluation provided by users did not necessarily match the technical assessment data. No correlation was observed between the general comfort and specific thermal comfort assessments. Finally, the identification of thermal discomfort by specific foot areas would be useful in the process of designing and developing boots.

  14. Light comfort zones of mesopelagic acoustic scattering layers in two contrasting optical environments

    NASA Astrophysics Data System (ADS)

    Røstad, Anders; Kaartvedt, Stein; Aksnes, Dag L.

    2016-07-01

    We make a comparison of the mesopelagic sound scattering layers (SLs) in two contrasting optical environments; the clear Red Sea and in murkier coastal waters of Norway (Masfjorden). The depth distributions of the SL in Masfjorden are shallower and narrower than those of the Red Sea. This difference in depth distribution is consistent with the hypothesis that the organisms of the SL distribute according to similar light comfort zones (LCZ) in the two environments. Our study suggest that surface and underwater light measurements ranging more than 10 orders of magnitude is required to assess the controlling effects of light on SL structure and dynamics.

  15. Sensor design for outdoor racing bicycle field testing for human vibration comfort evaluation

    NASA Astrophysics Data System (ADS)

    Vanwalleghem, Joachim; De Baere, Ives; Loccufier, Mia; Van Paepegem, Wim

    2013-09-01

    This paper is concerned with the vibrational comfort evaluation of the cyclist when cycling a rough surface. Outdoor comfort tests have so far only been done through instrumenting the bicycle with accelerometers. This work instruments a racing bicycle with custom-made contact force sensors and velocity sensors to acquire human comfort through the absorbed power method. Comfort evaluation is assessed at the hand-arm and seat interface of the cyclist with the bicycle. By means of careful finite-element analysis for designing the force gauges at the handlebar and the seat combined with precise calibration of both force and velocity sensors, all sensors have proven to work properly. Initial field tests are focused on the proper functioning of the designed sensors and their suitability for vibration comfort measurements. Tests on a cobblestone road reveal that the outcome of the absorbed power values is within the same range as those from laboratory tests found in the literature. This sensor design approach for outdoor testing with racing bicycles may give a new interpretation on evaluating the cyclist's comfort since the vibrational load is not only quantified in terms of acceleration but also in terms of force and velocity at the bicycle-cyclist contact points.

  16. Annoyance rate evaluation method on ride comfort of vehicle suspension system

    NASA Astrophysics Data System (ADS)

    Tang, Chuanyin; Zhang, Yimin; Zhao, Guangyao; Ma, Yan

    2014-03-01

    The existing researches of the evaluation method of ride comfort of vehicle mainly focus on the level of human feelings to vibration. The level of human feelings to vibration is influenced by many factors, however, the ride comfort according to the common principle of probability and statistics and simple binary logic is unable to reflect these uncertainties. The random fuzzy evaluation model from people subjective response to vibration is adopted in the paper, these uncertainties are analyzed from the angle of psychological physics. Discussing the traditional evaluation of ride comfort during vehicle vibration, a fuzzily random evaluation model on the basis of annoyance rate is proposed for the human body's subjective response to vibration, with relevant fuzzy membership function and probability distribution given. A half-car four degrees of freedom suspension vibration model is described, subject to irregular excitations from the road surface, with the aid of software Matlab/Simulink. A new kind of evaluation method for ride comfort of vehicles is proposed in the paper, i.e., the annoyance rate evaluation method. The genetic algorithm and neural network control theory are used to control the system. Simulation results are obtained, such as the comparison of comfort reaction to vibration environments between before and after control, relationship of annoyance rate to vibration frequency and weighted acceleration, based on ISO 2631/1(1982), ISO 2631-1(1997) and annoyance rate evaluation method, respectively. Simulated assessment results indicate that the proposed active suspension systems prove to be effective in the vibration isolation of the suspension system, and the subjective response of human being can be promoted from very uncomfortable to a little uncomfortable. Furthermore, the novel evaluation method based on annoyance rate can further estimate quantitatively the number of passengers who feel discomfort due to vibration. A new analysis method of vehicle

  17. Evaluation of thermal comfort conditions in Ourmieh Lake, Iran

    NASA Astrophysics Data System (ADS)

    Farajzadeh, Hassan; Matzarakis, Andreas

    2012-02-01

    Research in developing countries concerning the relationship of weather and climate conditions with tourism shows a high importance not only because of financial aspects but also an important part of the region's tourism resource base. Monthly mean air temperature, relative humidity, precipitation, vapor pressure, wind velocity, and cloud cover for the period 1985-2005 data collected from four meteorological stations Tabriz, Maragheh, Orumieh, and Khoy were selected. The purpose of this study is to determine the most suitable months for human thermal comfort in Ourmieh Lake, a salt sea in the northwest of Iran. To achieve this, the cooling power and physiologically equivalent temperature (PET) calculated by the RayMan model and the Climate Tourism/Transfer Information Scheme (CTIS) were used. The results based on cooling power indicate that the most favorable period for tourism, sporting, and recreational activities in Ourmieh Lake is between June and October and based on PET between June to September. In addition, the CTIS shows a detailed quantification of the relevant climate-tourism factors.

  18. Acoustic evaluation and adjustment of an open-plan office through architectural design and noise control.

    PubMed

    Passero, Carolina Reich Marcon; Zannin, Paulo Henrique Trombetta

    2012-11-01

    Arranging office space into a single open room offers advantages in terms of easy exchange of information and interaction among coworkers, but reduces privacy and acoustic comfort. Thus, the purpose of this work was to evaluate the acoustic quality of a real open-plan office and to propose changes in the room to improve the acoustic conditioning of this office. The computational model of the office under study was calibrated based on RT and STI measurements. Predictions were made of the RT and STI, which generated the radius of distraction r(D), and the rate of spatial decay of sound pressure levels per distance doubling DL(2) in the real conditions of the office and after modifications of the room. The insertion of dividers between work stations and an increase in the ceiling's sound absorption improved the acoustic conditions in the office under study.

  19. On-Orbit Evaluation of a New Treadmill Harness for Improved Crewmember Comfort and Load Distribution

    NASA Technical Reports Server (NTRS)

    Perusek, G. P.; Sheehan, C. C.; Savina, M. C.; Owings, T. M.; Davis, B. L.; Ryder, J. W.

    2011-01-01

    The current design of the International Space Station (ISS) Treadmill Harness has been reported to cause pain and discomfort to crewmembers during exercise. The Harness Station Development Test Objective (SDTO) provided participating crewmembers (n = 6) with a new harness design, the "Glenn Harness," to evaluate for comfort and loading as compared to the current Treadmill Harness. A novel suite of load-sensing instrumentation was developed to noninvasively measure load distribution and provided a first-ever quantification of actual dynamic loads during treadmill exercise. In addition, crew debriefs provided feedback on harness preference and overall impressions. Conclusions: Post-flight analysis in returned Glenn Harnesses (n = 3) showed minimal wear and tear. Four of the six subjects found the Glenn Harness to be more comfortable in this on-orbit, side-by-side comparison as measured by the crew comfort questionnaire and crew debriefs. Specific areas for improvement have been identified, and forward recommendations will be provided to the Human Research Program. The protocol developed for the SDTO provided valuable insight into crew comfort issues, design improvements, and loading preferences for exercise harnessing, which lays the groundwork for better harnessing systems and training protocols.

  20. Understanding and Evaluating Human Thermal Comfort at Tertiary Level Using a Computer-Based Laboratory Teaching Tool

    ERIC Educational Resources Information Center

    Pellegrini, Marco

    2014-01-01

    Phase changes in water are experienced in everyday life but students often struggle to understand mechanisms that regulate them. Human thermal comfort is closely related to humidity, evaporative heat loss and heat transfer. The purpose of the present study is to assist students in the evaluation of human thermal comfort. Such a goal is achievable…

  1. Comment on "Increase in voice level and speaker comfort in lecture rooms" [J. Acoust. Soc. Am. 125, 2072-2082 (2009)] (L).

    PubMed

    Pelegrín-García, David

    2011-03-01

    Recently, a paper written by Brunskog Gade, Payá-Ballester and Reig-Calbo, "Increase in voice level and speaker comfort in lecture rooms" [J. Acoust. Soc. Am. 125, 2072-2082 (2009)] related teachers' variation in vocal intensity during lecturing to the room acoustic conditions, introducing an objective parameter called "room gain" to describe these variations. In a failed attempt to replicate the objective measurements by Brunskog et al., a simplified and improved method for the calculation of room gain is proposed, in addition with an alternative magnitude called "voice support." The measured parameters are consistent with those of other studies and are used here to build two empirical models relating the voice power levels measured by Brunskog et al., to the room gain and the voice support.

  2. Evaluation of Air Mixing and Thermal Comfort From High Sidewall Supply Air Jets

    SciTech Connect

    Ridouane, E. H.

    2011-09-01

    Uniform mixing of conditioned air with room air is an essential factor for providing comfort in homes. The higher the supply flow rates the easier to reach good mixing in the space. In high performance homes, however, the flow rates required to meet the small remaining thermal loads are not large enough to maintain uniform mixing in the space. The objective of this study is to resolve this issue and maintain uniform temperatures within future homes. We used computational fluid dynamics modeling to evaluate the performance of high sidewall air supply for residential applications in heating and cooling modes. Parameters of the study are the supply velocity, supply temperature, diffuser dimensions, and room dimensions. Laboratory experiments supported the study of thermal mixing in heating mode; we used the results to develop a correlation to predict high sidewall diffuser performance. For cooling mode, numerical analysis is presented. The results provide information to guide the selection of high sidewall supply diffusers to maintain proper room mixing for heating and cooling of high performance homes. It is proven that these systems can achieve good mixing and provide acceptable comfort levels. Recommendations are given on the operating conditions to guarantee occupant comfort.

  3. Disability evaluation in acoustic blast trauma

    PubMed Central

    Raju, Ganesan

    2015-01-01

    Introduction: Acoustic blast trauma is different from Noise induced hearing loss. Blast trauma can damage the tympanic membrane, ossicles and cochlea singly or in combination. It produces immediate severe hearing loss and may be associated with tinnitus and vestibular symptoms. Hearing loss recovers spontaneously in many cases but may be permanent in 30-55% cases. Thirteen patients working in an explosive manufacturing unit in Andhra Pradesh were exposed to blast trauma at work place. All these workers complained of immediate hearing loss and were subjected to audiological investigations. Methods: Initial evaluation showed a severe sensorineural type of hearing loss 10 of the 13 cases (77%). They were referred to our Medical board for disability evaluation after 2-3 years of initial injury. Pure tone audiometry indicated severe hearing loss in 12 of 13 cases (92%) that was not correlating clinically. Re-evaluation with Acoustic reflex and ABR (BERA) tests were done and permanent disability was evaluated with the results of these investigations. Observations: No significant hearing loss was found in most patients and these patients had minimal disability. Conclusion: Objective hearing tests should be carried out after one year or more before evaluation of permanent disability. PMID:26957811

  4. Ergonomics and comfort in lawn mower handle positioning: An evaluation of handle geometry.

    PubMed

    Lowndes, Bethany R; Heald, Elizabeth A; Hallbeck, M Susan

    2015-11-01

    Hand operation accompanied with any combination of large forces, awkward positions and repetition may lead to upper limb injury or illness and may be exacerbated by vibration. Commercial lawn mowers expose operators to these factors during actuation of hand controls and therefore may be a health concern. A nontraditional lawn mower control system may decrease upper limb illnesses and injuries through more neutral hand and body positioning. This study compared maximum grip strength in twelve different orientations (3 grip spans and 4 positions) and evaluated self-described comfortable handle positions. The results displayed force differences between nontraditional (X) and both vertical (V) and pistol (P) positions (p < 0.0001) and among the different grip spans (p < 0.0001). Based on these results, recommended designs should incorporate a tilt between 45 and 70°, handle rotations between 48 and 78°, and reduced force requirements or decreased grip spans to improve user health and comfort. PMID:26154198

  5. Final evaluation of the acoustics of the APS conference center

    SciTech Connect

    Restrepo, J.M.

    1995-11-01

    Along with a description of the changes that I prescribed on the original design, this report is an evaluation of the acoustical properties of the new Advanced Photon Source Auditorium at Argonne National Laboratory. Acoustical deficiencies in the hall are presented with several options for their expedient and economical solution.

  6. EVALUATION OF ACOUSTIC FORCES ON A PARTICLE IN AEROSOL MEDIUM

    SciTech Connect

    Lee, S; Richard Dimenna, R

    2007-09-27

    The acoustic force exerted on a solid particle was evaluated to develop a fundamental understanding of the critical physical parameters or constraints affecting particle motion and capture in a collecting device. The application of an acoustic force to the collection of a range of submicron-to-micron particles in a highly turbulent airflow stream laden with solid particles was evaluated in the presence of other assisting and competing forces. This scoping estimate was based on the primary acoustic force acting directly on particles in a dilute aerosol system, neglecting secondary interparticle effects such as agglomeration of the sub-micron particles. A simplified analysis assuming a stable acoustic equilibrium with an infinite sound speed in the solid shows that for a solid-laden air flow in the presence of a standing wave, particles will move toward the nearest node. The results also show that the turbulent drag force on a 1-{micro}m particle resulting from eddy motion is dominant when compared with the electrostatic force or the ultrasonic acoustic force. At least 180 dB acoustic pressure level at 1 MHz is required for the acoustic force to be comparable to the electrostatic or turbulent drag forces in a high-speed air stream. It is noted that particle size and pressure amplitude are dominant parameters for the acoustic force. When acoustic pressure level becomes very large, the acoustic energy will heat up the surrounding air medium, which may cause air to expand. With an acoustic power of about 600 watts applied to a 2000-lpm air flow, the air temperature can increase by as much as 15 C at the exit of the collector.

  7. Subjective evaluation of speech and noise in learning environments in the realm of classroom acoustics: Results from laboratory and field experiments

    NASA Astrophysics Data System (ADS)

    Meis, Markus; Nocke, Christian; Hofmann, Simone; Becker, Bernhard

    2005-04-01

    The impact of different acoustical conditions in learning environments on noise annoyance and the evaluation of speech quality were tested in a series of three experiments. In Experiment 1 (n=79) the auralization of seven classrooms with reverberation times from 0.55 to 3.21 s [average between 250 Hz to 2 kHz] served to develop a Semantic Differential, evaluating a simulated teacher's voice. Four factors were found: acoustical comfort, roughness, sharpness, and loudness. In Experiment 2, the effects of two classroom renovations were examined from a holistic perspective. The rooms were treated acoustically with acoustic ceilings (RT=0.5 s [250 Hz-2 kHz]) and muffling floor materials as well as non-acoustically with a new lighting system and color design. The results indicate that pupils (n=61) in renovated classrooms judged the simulated voice more positively, were less annoyed from the noise in classrooms, and were more motivated to participate in the lessons. In Experiment 3 the sound environments from six different lecture rooms (RT=0.8 to 1.39 s [250 Hz-2 kHz]) in two Universities of Oldenburg were evaluated by 321 students during the lectures. Evidence found supports the assumption that acoustical comfort in rooms is dependent on frequency for rooms with higher reverberation times.

  8. Comfort Assessment of Personal Protection Systems During Total Joint Arthroplasty Using a Novel Multidimensional Evaluation Tool

    PubMed Central

    Malik, MHA; Handford, Elizabeth; Staniford, Elaine; Gambhir, AK; Kay, PR

    2006-01-01

    INTRODUCTION A number of studies have assessed the usefulness of surgical gowns and exhaust suits with regards to barrier function and protection afforded to healthcare workers from blood strike-through, splashes and aerosols. PATIENTS AND METHODS We have performed a comfort assessment comparison between the Charnley exhaust suit, disposable gown plus visor and the Stryker Steri-Shield system using a newly developed objective multidimensional ergonomic tool designed to measure wearable comfort across the dimensions of emotion, attachment, harm, perceived change, movement and anxiety. RESULTS The total mean Comfort Rating Scale value for a disposable gown plus visor was 16.1 with a mean dimensional score of 2.7 (range, 0.2–8.4), for the Charnley system the values were 51.4 and 8.6 (range, 5.9–12.8), respectively, and for the Stryker Steri-Shield 15.4 and 2.6 (range, 0.8–5.6). CONCLUSIONS The Steri-Shield system provides the least variation in comfort and, as such, may offer the best combination of comfort, protective qualities and form or style of personal protection equipment for lower limb arthroplasty operations. PMID:17002852

  9. Digital evaluation of sitting posture comfort in human-vehicle system under Industry 4.0 framework

    NASA Astrophysics Data System (ADS)

    Tao, Qing; Kang, Jinsheng; Sun, Wenlei; Li, Zhaobo; Huo, Xiao

    2016-09-01

    Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV(whole body vibration) test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.

  10. Evaluating Different Green School Building Designs for Albania: Indoor Thermal Comfort, Energy Use Analysis with Solar Systems

    NASA Astrophysics Data System (ADS)

    Dalvi, Ambalika Rajendra

    Improving the conditions of schools in many parts of the world is gradually acquiring importance. The Green School movement is an integral part of this effort since it aims at improving indoor environmental conditions. This would in turn, enhance student- learning while minimizing adverse environmental impact through energy efficiency of comfort-related HVAC and lighting systems. This research, which is a part of a larger research project, aims at evaluating different school building designs in Albania in terms of energy use and indoor thermal comfort, and identify energy efficient options of existing schools. We start by identifying three different climate zones in Albania; Coastal (Durres), Hill/Pre-mountainous (Tirana), mountainous (Korca). Next, two prototypical school building designs are identified from the existing stock. Numerous scenarios are then identified for analysis which consists of combinations of climate zone, building type, building orientation, building upgrade levels, presence of renewable energy systems (solar photovoltaic and solar water heater). The existing building layouts, initially outlined in CAD software and then imported into a detailed building energy software program (eQuest) to perform annual simulations for all scenarios. The research also predicted indoor thermal comfort conditions of the various scenarios on the premise that windows could be opened to provide natural ventilation cooling when appropriate. This study also estimated the energy generated from solar photovoltaic systems and solar water heater systems when placed on the available roof area to determine the extent to which they are able to meet the required electric loads (plug and lights) and building heating loads respectively. The results showed that there is adequate indoor comfort without the need for mechanical cooling for the three climate zones, and that only heating is needed during the winter months.

  11. Evaluation of acoustic beacon characteristics for navigation tasks.

    PubMed

    Tran, T V; Letowski, T; Abouchacra, K S

    2000-06-01

    The goal of the present study was to investigate the human factors issues related to acoustic beacons used for auditory navigation. Specific issues addressed were: (1) the effect of various beacon characteristics on human accuracy in turning toward the direction of the acoustic beacon; (2) the difference between real and virtual environments on human accuracy in turning toward the acoustic beacon; and (3) the perceived sound quality of various acoustic beacons. Three experiments were conducted in which acoustic beacons were presented in a background of 80 dBA pink noise. Results of the localization tasks revealed that (a) presentation mode (continuous versus pulsed beacon sound) did not affect the overall localization accuracy or number of front-back confusion errors; and (b) the type of acoustic beacon affected the size of localization error. Results of the sound quality assessment indicated that listeners had definite preferences regarding the type of sound being used as a beacon, with (a) non-speech beacons preferred over speech beacons, (b) a beacon repetition rate of 1.1 rps preferred over either the 0.7 or 2.5 rps rates, and (c) a continuous operation of a beacon preferred over a pulsed operation. Finally, sound quality ratings and localization errors were highly negatively correlated. This finding demonstrates the usefulness and practical values of sound quality judgements for audio display design and evaluation.

  12. Assessment of comfort of various hearing protection devices (HPD).

    PubMed

    Bhattacharya, S K; Tripathi, S R; Kashyap, S K

    1993-12-01

    To evaluate the comfort of hearing protection devices, two models of ear plugs and five models of ear muffs were tested. The psychophysical method of 'single stimuli' was applied on a group of 30 subjects with or without wearing the devices for a short duration of 15 min under noise condition of 100 dBa in the acoustic chamber as also on a group of 10 weavers with the protection devices worn for longer durations of 1 h, 4 h and 8 h under noise exposure of 102-104 dBA in the weaving shed. Each subject performed 8 trials with each type of device on different days. Application force and tightness of spring were also evaluated. The results yielded a comfort grading for hearing protection devices. The comfort grading, however, depended on several factors in addition to application force and tightness of spring, which has been discussed.

  13. Evaluation of Air Mixing and Thermal Comfort From High Sidewall Supply Air Jets

    SciTech Connect

    Ridouane, El Hassan

    2011-09-01

    Uniform mixing of conditioned air with room air is an essential factor for providing comfort in homes. The objective of the study outlined in this report is to resolve the issue that the flow rates that are required to meet the small remaining thermal loads are not large enough to maintain uniform mixing in the space.and maintain uniform temperatures within future homes. The results provide information to guide the selection of high sidewall supply diffusers to maintain proper room mixing for heating and cooling of high performance homes.

  14. Effect evaluation of a heated ambulance mattress-prototype on body temperatures and thermal comfort - an experimental study

    PubMed Central

    2014-01-01

    Background Exposure to cold temperatures is, often, a neglected problem in prehospital care. One of the leading influences of the overall sensation of cold discomfort is the cooling of the back. The aim of this study was to evaluate the effect of a heated ambulance mattress-prototype on body temperatures and thermal comfort in an experimental study. Method Data were collected during four days in November, 2011 inside and outside of a cold chamber. All participants (n = 23) participated in two trials each. In one trial, they were lying on a stretcher with a supplied heated mattress and in the other trial without a heated mattress. Outcomes were back temperature, finger temperature, core body temperature, Cold Discomfort Scale (CDS), four statements from the state-trait anxiety – inventory (STAI), and short notes of their experiences of the two mattresses. Data were analysed both quantitatively and qualitatively. A repeated measure design was used to evaluate the effect of the two mattresses. Results A statistical difference between the regular mattress and the heated mattress was found in the back temperature. In the heated mattress trial, the statement “I am tense” was fewer whereas the statements “I feel comfortable”, “I am relaxed” and “I feel content” were higher in the heated mattress trial. The qualitative analyses of the short notes showed that the heated mattress, when compared to the unheated mattress, was experienced as warm, comfortable, providing security and was easier to relax on. Conclusions Heat supply from underneath the body results in increased comfort and may prevent hypothermia which is important for injured and sick patients in ambulance care. PMID:25103366

  15. Evaluation of solar cell welds by scanning acoustic microscopy

    NASA Technical Reports Server (NTRS)

    Klima, S. J.; Frey, W. E.; Baraona, C. R.

    1982-01-01

    Scanning laser acoustic microscopy was used to nondestructively evaluate solar cell interconnect bonds made by resistance welding. Both copper-silver and silver-silver welds were analyzed. The bonds were produced either by a conventional parallel-gap welding technique using rectangular electrodes or new annular gap design with a circular electrode cross section. With the scanning laser acoustic microscope, it was possible to produce a real time television image which reveales the weld configuration as it relates to electrode geometry. The effect of electrode misalinement with the surface of the cell was also determined. A preliminary metallographic analysis was performed on selected welds to establish the relationship between actual size and shape of the weld area and the information available from acoustic micrographs.

  16. Comparison of digital and conventional impression techniques: evaluation of patients’ perception, treatment comfort, effectiveness and clinical outcomes

    PubMed Central

    2014-01-01

    Background The purpose of this study was to compare two impression techniques from the perspective of patient preferences and treatment comfort. Methods Twenty-four (12 male, 12 female) subjects who had no previous experience with either conventional or digital impression participated in this study. Conventional impressions of maxillary and mandibular dental arches were taken with a polyether impression material (Impregum, 3 M ESPE), and bite registrations were made with polysiloxane bite registration material (Futar D, Kettenbach). Two weeks later, digital impressions and bite scans were performed using an intra-oral scanner (CEREC Omnicam, Sirona). Immediately after the impressions were made, the subjects’ attitudes, preferences and perceptions towards impression techniques were evaluated using a standardized questionnaire. The perceived source of stress was evaluated using the State-Trait Anxiety Scale. Processing steps of the impression techniques (tray selection, working time etc.) were recorded in seconds. Statistical analyses were performed with the Wilcoxon Rank test, and p < 0.05 was considered significant. Results There were significant differences among the groups (p < 0.05) in terms of total working time and processing steps. Patients stated that digital impressions were more comfortable than conventional techniques. Conclusions Digital impressions resulted in a more time-efficient technique than conventional impressions. Patients preferred the digital impression technique rather than conventional techniques. PMID:24479892

  17. Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics

    NASA Technical Reports Server (NTRS)

    Cantrell, John H., Jr.

    2008-01-01

    Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture. A method based on nonlinear acoustics is shown to provide such a means to assess the state of metal fatigue. The salient features of an analytical model are presented of the microelastic-plastic nonlinearities resulting from the interaction of an acoustic wave with fatigue-generated dislocation substructures and cracks that predictably evolve during the metal fatigue process. The interaction is quantified by the material (acoustic) nonlinearity parameter extracted from acoustic harmonic generation measurements. The parameters typically increase monotonically by several hundred percent over the fatigue life of the metal, thus providing a unique measure of the state of fatigue. Application of the model to aluminum alloy 2024-T4, 410Cb stainless steel, and IN100 nickel-base superalloy specimens fatigued using different loading conditions yields good agreement between theory and experiment. Application of the model and measurement technique to the on-site inspection of steam turbine blades is discussed.

  18. Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics

    NASA Astrophysics Data System (ADS)

    Cantrell, John H.

    2009-03-01

    Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture. A method based on nonlinear acoustics is shown to provide such a means to assess the state of metal fatigue. The salient features of an analytical model are presented of the microelastic-plastic nonlinearities resulting from the interaction of an acoustic wave with fatigue-generated dislocation substructures and cracks that predictably evolve during the metal fatigue process. The interaction is quantified by the material (acoustic) nonlinearity parameter β extracted from acoustic harmonic generation measurements. The β parameters typically increase monotonically by several hundred percent over the fatigue life of the metal, thus providing a unique measure of the state of fatigue. Application of the model to aluminum alloy 2024-T4 and 410 Cb stainless steel specimens fatigued using different loading conditions yields good agreement between theory and experiment. Application of the model and measurement technique to the on-site inspection of steam turbine blades is discussed.

  19. Evaluation of thermal comfort in university classrooms through objective approach and subjective preference analysis.

    PubMed

    Nico, Maria Anna; Liuzzi, Stefania; Stefanizzi, Pietro

    2015-05-01

    Assessing thermal comfort becomes more relevant when the aim is to maximise learning and productivity performances, as typically occurs in offices and schools. However, if, in the offices, the Fanger model well represents the thermal occupant response, then on the contrary, in schools, adaptive mechanisms significantly influence the occupants' thermal preference. In this study, an experimental approach was performed in the Polytechnic University of Bari, during the first days of March, in free running conditions. First, the results of questionnaires were compared according to the application of the Fanger model and the adaptive model; second, using a subjective scale, a complete analysis was performed on thermal preference in terms of acceptability, neutrality and preference, with particular focus on the influence of gender. The user possibility to control the indoor plant system produced a significant impact on the thermal sensation and the acceptability of the thermal environment. Gender was also demonstrated to greatly influence the thermal judgement of the thermal environment when an outdoor cold climate occurs.

  20. The acoustical diary as an innovative tool in soundscape evaluation

    NASA Astrophysics Data System (ADS)

    Schulte-Fortkamp, Brigitte; Genuit, Klaus

    2001-05-01

    A new field study evaluating soundscapes investigates closely the reactions of traffic noise with a particular regard to the street surface. The combination of methods with different sensibilities for the subject's process of perceiving and evaluating noise in such ambiences is necessary for a reliable and valid analysis and interpretation of data. Acoustic measurements are carried out in critical segments of the street as well as in the respective apartments of the inhabitants, which are questioned in narrative interviews. The acoustic measurements are taken simultaneously in the apartment and on the street. Apartments were selected which issue into the street; outside measurements are performed in front of the buildings on the sidewalk. During the interviews in the apartments the occurring noises are registered by noisebook. As a rule the measurement spot within the apartment is the area in which the interviewed person mostly resides, when he/she takes repose. Further analysis points out the importance of an extended evaluation with an acoustical diary which combines technical and sociological measurement procedures. Performance of the entire data collection process and first results will be discussed.

  1. Primary Care Pediatricians' Experience, Comfort and Competence in the Evaluation and Management of Child Maltreatment: Do We Need Child Abuse Experts?

    ERIC Educational Resources Information Center

    Lane, Wendy G.; Dubowitz, Howard

    2009-01-01

    Objective: We assessed the self-reported experience, comfort and competence of primary care pediatricians in evaluating and managing child maltreatment (CM), in rendering opinions regarding the likelihood of CM, and in providing court testimony. We examined pediatricians' need for expert consultation when evaluating possible maltreatment. Methods:…

  2. Fundamental Potential for Acoustic Microscopy Evaluation of Dental Tissues

    NASA Astrophysics Data System (ADS)

    Denisova, L. A.; Maev, R. Gr.; Rusanov, F. S.; Maeva, A. R.; Denisov, A. F.; Gavrilov, D. Yu.; Bakulin, E. Yu.; Severin, F. M.

    Comprehensive analysis of the present-day acoustic microscopy experimental approaches from the standpoint of their potential application in dental research and diagnostics has been performed. Whole extracted human teeth and specially prepared dental tissue samples have been investigated. The results of the study demonstrate that there are several experimental techniques that can be used for precise quantitative evaluation of the tissues local mechanical properties in flat-parallel teeth slices, for the pathomorphological investigation of the tissues strength spatial distribution in flat cuts. In the whole tooth, the acoustic microscopy techniques allow us to precisely measure the enamel and dentine layers thickness, the distance between the external surface and pulp, to reveal hidden caries and restoration disbonding. These opportunities form a real ground for the further design of the special acousto-microscopical methods and new equipment for the clinical diagnostics

  3. Evaluating a topographical mapping from speech acoustics to tongue positions

    SciTech Connect

    Hogden, J.; Heard, M.

    1995-05-01

    The {ital continuity} {ital mapping} algorithm---a procedure for learning to recover the relative positions of the articulators from speech signals---is evaluated using human speech data. The advantage of continuity mapping is that it is an unsupervised algorithm; that is, it can potentially be trained to make a mapping from speech acoustics to speech articulation without articulator measurements. The procedure starts by vector quantizing short windows of a speech signal so that each window is represented (encoded) by a single number. Next, multidimensional scaling is used to map quantization codes that were temporally close in the encoded speech to nearby points in a {ital continuity} {ital map}. Since speech sounds produced sufficiently close together in time must have been produced by similar articulator configurations, and speech sounds produced close together in time are close to each other in the continuity map, sounds produced by similar articulator positions should be mapped to similar positions in the continuity map. The data set used for evaluating the continuity mapping algorithm is comprised of simultaneously collected articulator and acoustic measurements made using an electromagnetic midsagittal articulometer on a human subject. Comparisons between measured articulator positions and those recovered using continuity mapping will be presented.

  4. Evaluation of Sleeping Comfort of Bed Mattresses using Physiological and Psychological Response Measurements

    NASA Astrophysics Data System (ADS)

    Aoi, Masataka; Kamijo, Masayoshi; Yoshida, Hiroaki

    The purpose of this study is to create a method of evaluating the quality of sleep based on the elastic properties of bed mattresses through measurement of physiological and psychological responses while sleeping. We gathered Profile of Mood States (POMS) results before and after sleep, and investigated changes in subjects' moods according to sleep. A total of 4 bed mattresses with different degrees of elasticity were prepared. They were all pocket coil mattresses. We conducted polysomnography (PSG) testing on subjects with a bioamplifier while they slept in each bed mattress, so that sleeping depth indicating the quality of sleep could be estimated. PSG is a comprehensive recording of the biophysiological changes that occur during sleep. As a result, the sleep depth of bed mattress with a high degree of elasticity increased in the PSG evaluation. Because the hip sinks in deeply from the waist, it is not easy to turn over on mattresses with a low degree of elasticity. We have therefore considered that the sleep depth of the subjects became shallow as a result. We have concluded that it is possible to estimate the quality of sleep through analysis of PSG and POMS results.

  5. Test Plan to Evaluate the Relationship Among IAQ, Comfort, Moisture, and Ventilation in Humid Climates

    SciTech Connect

    Widder, Sarah H.; Martin, Eric

    2013-03-15

    This experimental plan describes research being conducted by Pacific Northwest National Laboratory (PNNL), in coordinatation with Florida Solar Energy Center (FSEC), Florida HERO, and Lawrence Berkeley National Laboratory (LBNL) to evaluate the impact of ventilation rate on interior moisture levels, temperature distributions, and indoor air contaminant concentrations. Specifically, the research team will measure concentrations of indoor air contaminants, ventilation system flow rates, energy consumption, and temperature and relative humidity in ten homes in Gainesville, FL to characterize indoor pollutant levels and energy consumption associated with the observed ventilation rates. PNNL and FSEC have collaboratively prepared this experimental test plan, which describes background and context for the proposed study; the experimental design; specific monitoring points, including monitoring equipment, and sampling frequency; key research questions and the associated data analysis approach; experimental logistics, including schedule, milestones, and team member contact information; and clearly identifies the roles and responsibilities of each team in support of project objectives.

  6. Assessment of man's thermal comfort in practice

    PubMed Central

    Fanger, P. O.

    1973-01-01

    Fanger, P. O. (1973).British Journal of Industrial Medicine,30, 313-324. Assessment of man's thermal comfort in practice. A review is given of existing knowledge regarding the conditions for thermal comfort. Both physiological and environmental comfort conditions are discussed. Comfort criteria are shown diagrammatically, and their application is illustrated by numerous practical examples. Furthermore, the effect on the comfort conditions of age, adaptation, sex, seasonal and circadian rhythm, and unilateral heating or cooling of the body is discussed. The term `climate monotony' is considered. A method is recommended for the evaluation of the quality of thermal environments in practice. Images PMID:4584998

  7. Engine exhaust characteristics evaluation in support of aircraft acoustic testing

    NASA Astrophysics Data System (ADS)

    Ennix, Kimberly A.

    1994-02-01

    NASA Dryden Flight Research Facility and NASA Langley Research Center completed a joint acoustic flight test program. Test objectives were (1) to quantify and evaluate subsonic climb-to-cruise noise and (2) to obtain a quality noise database for use in validating the Aircraft Noise Prediction Program. These tests were conducted using aircraft with engines that represent the high nozzle pressure ratio of future transport designs. Test flights were completed at subsonic speeds that exceeded Mach 0.3 using F-18 and F-16XL aircraft. This paper describes the efforts of NASA Dryden Flight Research Facility in this flight test program. Topics discussed include the test aircraft, setup, and matrix. In addition, the engine modeling codes and nozzle exhaust characteristics are described.

  8. Engine exhaust characteristics evaluation in support of aircraft acoustic testing

    NASA Technical Reports Server (NTRS)

    Ennix, Kimberly A.

    1994-01-01

    NASA Dryden Flight Research Facility and NASA Langley Research Center completed a joint acoustic flight test program. Test objectives were (1) to quantify and evaluate subsonic climb-to-cruise noise and (2) to obtain a quality noise database for use in validating the Aircraft Noise Prediction Program. These tests were conducted using aircraft with engines that represent the high nozzle pressure ratio of future transport designs. Test flights were completed at subsonic speeds that exceeded Mach 0.3 using F-18 and F-16XL aircraft. This paper describes the efforts of NASA Dryden Flight Research Facility in this flight test program. Topics discussed include the test aircraft, setup, and matrix. In addition, the engine modeling codes and nozzle exhaust characteristics are described.

  9. Engine exhaust characteristics evaluation in support of aircraft acoustic testing

    NASA Technical Reports Server (NTRS)

    Ennix, Kimberly A.

    1993-01-01

    NASA Dryden Flight Research Facility and NASA Langley Research Center completed a joint acoustic flight test program. Test objectives were (1) to quantify and evaluate subsonic climb-to-cruise noise and (2) to obtain a quality noise database for use in validating the Aircraft Noise Prediction Program. These tests were conducted using aircraft with engines that represent the high nozzle pressure ratio of future transport designs. Test flights were completed at subsonic speeds that exceeded Mach 0.3 using F-18 and F-16XL aircraft. This paper describes the efforts of NASA Dryden Flight Research Facility in this flight test program. Topics discussed include the test aircraft, setup, and matrix. In addition, the engine modeling codes and nozzle exhaust characteristics are described.

  10. Effect evaluation of a heated ambulance mattress-prototype on thermal comfort and patients’ temperatures in prehospital emergency care – an intervention study

    PubMed Central

    Aléx, Jonas; Karlsson, Stig; Björnstig, Ulf; Saveman, Britt-Inger

    2015-01-01

    Background The ambulance milieu does not offer good thermal comfort to patients during the cold Swedish winters. Patients’ exposure to cold temperatures combined with a cold ambulance mattress seems to be the major factor leading to an overall sensation of discomfort. There is little research on the effect of active heat delivered from underneath in ambulance care. Therefore, the aim of this study was to evaluate the effect of an electrically heated ambulance mattress-prototype on thermal comfort and patients’ temperatures in the prehospital emergency care. Methods A quantitative intervention study on ambulance care was conducted in the north of Sweden. The ambulance used for the intervention group (n=30) was equipped with an electrically heated mattress on the regular ambulance stretcher whereas for the control group (n=30) no active heat was provided on the stretcher. Outcome variables were measured as thermal comfort on the Cold Discomfort Scale (CDS), subjective comments on cold experiences, and finger, ear and air temperatures. Results Thermal comfort, measured by CDS, improved during the ambulance transport to the emergency department in the intervention group (p=0.001) but decreased in the control group (p=0.014). A significant higher proportion (57%) of the control group rated the stretcher as cold to lie down compared to the intervention group (3%, p<0.001). At arrival, finger, ear and compartment air temperature showed no statistical significant difference between groups. Mean transport time was approximately 15 minutes. Conclusions The use of active heat from underneath increases the patients’ thermal comfort and may prevent the negative consequences of cold stress. PMID:26374468

  11. Safety and comfort evaluation of a new formulation of Visine® lubricant eye drops containing HydroBlend™ and GentlePur™

    PubMed Central

    Torkildsen, Gail; Frisch, Sherryl; Bai, Mingqi; Gentner, Louis; Doshi, Uday; Zhang, Jane

    2016-01-01

    Purpose To evaluate the clinical safety and comfort of a new benzalkonium chloride-free Visine® lubricant eye drop formulation (Hydroblend™ and GentlePur™) in healthy and dry eye subjects. Methods This was a single-site, open-label clinical study comprised of 22 healthy and 22 dry eye subjects. Subjects were instructed to instill 1–2 drops of the test product four times a day for 2 weeks and were examined at visit 1 (day 0), visit 2 (day 7), and visit 3 (day 14). Assessments at each visit included postdosing product usage comfort scores, predosing fluorescein corneal staining score, predosing visual acuity, and pre- and postdosing ocular structure change using slit-lamp biomicroscopy. Adverse events were monitored throughout the course of the study. Results Throughout the 14 days of the trial period, subjects from both healthy and dry eye groups rated the eye drops as “very comfortable”. For dry eye group, the mean product usage comfort scores for the first 3 minutes postdosing ranged from 8.5 to 8.8 at visit 1 and 9.2 to 9.6 at visit 3 on a 0–10 point scale, with 0 being very uncomfortable and 10 being very comfortable. The mean corneal staining scores over five corneal regions changed from 0.65 at visit 1 to 0.39 at visit 3 for dry eye group. The individual region corneal staining scores were also decreased from visits 1 to 3 for dry eye group. All subjects maintained pretreatment means visual acuity at visits 2 and 3. Biomicroscopic examination indicated no structural changes at all visits. There were no significant adverse events reported during the course of the study. Conclusion The study confirms that GentlePur™ is an appropriate choice as a preservative for ocular application. The new formulation was safe and comfortable when used four times a day in healthy and dry eye subjects. PMID:26929596

  12. Post Test Evaluation of HSCT Nozzle Acoustic Liner Subcomponents Subjected to a Hot Acoustic Durability Test

    NASA Technical Reports Server (NTRS)

    Verrilli, Michael J.; Lee, Kuan

    2008-01-01

    The acoustic liner system designed for use in the High Speed Civil Transport (HSCT) was tested in a thermal-acoustic environment. Five ceramic matrix composite (CMC) acoustic tile configurations, five bulk acoustic absorbers, and one thermal protection system design were tested. The CMC acoustic tiles were subjected to two 2 3/4 hr ambient temperature acoustic exposures to measure their dynamic response. One exposure was conducted on the tiles alone and the second exposure included the tiles and the T-foam bulk absorber. The measured tile RMS strains were small. With or without the T-foam absorber, the dynamic strains were below strain levels that would cause damage during fatigue loading. After the ambient exposure, a 75-hr durability test of the entire acoustic liner system was conducted using a thermal-acoustic cycle that approximated the anticipated service cycle. Acoustic loads up to 139 dB/Hz and temperatures up to 1670 F (910 C) were employed during this 60 cycle test. During the durability test, the CMC tiles were exposed to temperatures up to 1780 F and a transient through thickness gradient up to 490 F. The TPS peak temperatures on the hot side of the panels ranged from 750 to 1000 F during the 60 cycles. The through thickness delta T ranged from 450 to 650 F, varying with TPS location and cycle number. No damage, such as cracks or chipping, was observed in the CMC tiles after completion of the testing. However, on tile warped during the durability test and was replaced after 43 or 60 cycles. No externally observed damage was found in this tile. No failure of the CMC fasteners occurred, but damage was observed. Cracks and missing material occurred, only in the fastener head region. No indication of damage was observed in the T-foam acoustic absorbers. The SiC foam acoustic absorber experienced damage after about 43 cycles. Cracking in the TPS occurred around the attachment holes and under a vent. In spite of the development of damage, the TPS maintained

  13. Air-coupled acoustic thermography for in-situ evaluation

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N. (Inventor); Winfree, William P. (Inventor); Yost, William T. (Inventor)

    2010-01-01

    Acoustic thermography uses a housing configured for thermal, acoustic and infrared radiation shielding. For in-situ applications, the housing has an open side adapted to be sealingly coupled to a surface region of a structure such that an enclosed chamber filled with air is defined. One or more acoustic sources are positioned to direct acoustic waves through the air in the enclosed chamber and towards the surface region. To activate and control each acoustic source, a pulsed signal is applied thereto. An infrared imager focused on the surface region detects a thermal image of the surface region. A data capture device records the thermal image in synchronicity with each pulse of the pulsed signal such that a time series of thermal images is generated. For enhanced sensitivity and/or repeatability, sound and/or vibrations at the surface region can be used in feedback control of the pulsed signal applied to the acoustic sources.

  14. Cancer patients caregivers comfort.

    PubMed

    de Araújo Lamino, Daniela; Turrini, Ruth Natalia Teresa; Kolcaba, Katharine

    2014-04-01

    Cross-sectional study, carried out at the outpatient clinic of an oncology hospital. Data were collected from 88 caregivers of cancer patients using the Caregiver General Comfort Questionnaire (GCQ) to assess the caregivers' comfort. The caregivers' GCQ score mean was 203.9; better comfort scores was associated with age, care time and current occupation; positive aspects of comfort were related to the fact that caregivers felt loved, to patients' physical and environmental comfort and to caregivers' spirituality. 203.9; better comfort scores were associated with age of the caregiver and current occupation; positive aspects of comfort were related to the fact that caregivers felt loved, to patients' physical and environmental comfort and to caregivers' spirituality. Caregivers, who didn't have a paid job or leisure's activities showed a worse GCQ. The GCQ scale can help to identify factors that interfere in caregivers' comfort, as well as needs that can be modified through health professionals' interventions.

  15. Electret Acoustic Transducer Array For Computerized Ultrasound Risk Evaluation System

    DOEpatents

    Moore, Thomas L.; Fisher, Karl A.

    2005-08-09

    An electret-based acoustic transducer array is provided and may be used in a system for examining tissue. The acoustic transducer array is formed with a substrate that has a multiple distinct cells formed therein. Within each of the distinct cells is positioned an acoustic transducing element formed of an electret material. A conductive membrane is formed over the distinct cells and may be flexible.

  16. [Evaluation of acoustic effectiveness of personnel protectors from extra-aural exposure to aviation noise].

    PubMed

    Dragan, S P; Soldatov, S K; Bogomolov, A V; Drozdov, S V; Poliakov, N M

    2013-01-01

    Purpose of the investigation was to validate testing acoustic effectiveness of a personnel vest-like protector (PP) from extra-aural exposure to aviation noise. Levels of aviation noise for PP testing were determined through calculation. Vest effectiveness in protecting from acoustic vibration generated by high-intensity aviation noise was evaluated both in laboratory and field tests. For comparison analysis, PP was also tested with a dummy exposed on a special tester, i.e. acoustic interferometer.

  17. Evaluation of an Educational Workshop to Increase Comfort Levels of Professional Caregivers with End-of-Life Care.

    PubMed

    Corcoran, Karen

    2016-01-01

    A workshop to enable professional caregivers to meet the needs of patients, families, and themselves during the end-of-life process is described. This quality initiative sought to improve professional caregivers' comfort with end-of-life care through use of an education intervention. PMID:27323469

  18. Evaluation of an Educational Workshop to Increase Comfort Levels of Professional Caregivers with End-of-Life Care.

    PubMed

    Corcoran, Karen

    2016-01-01

    A workshop to enable professional caregivers to meet the needs of patients, families, and themselves during the end-of-life process is described. This quality initiative sought to improve professional caregivers' comfort with end-of-life care through use of an education intervention.

  19. Evaluation of Space Transportation System (STS) OV-102 orbiter payload bay acoustic environment

    NASA Technical Reports Server (NTRS)

    On, F. J.

    1982-01-01

    This report presents the results of a statistical analysis and evaluation performed by the Mechanical Engineering Branch (Code 731) on the payload bay internal acoustic data measured on the STS-1 through STS-4 flights. The results are used as a basis for developing the required baseline acoustic environment specification to be used in establishing design and test criteria for STS payloads and components.

  20. Determining the bioclimatic comfort in Kastamonu City.

    PubMed

    Cetin, Mehmet

    2015-10-01

    Bioclimatic comfort defines the optimal climatic conditions in which people feel healthy and dynamic. Bioclimatic comfort mapping methods are useful to urban managers and planners. For the purposes of planning, climatic conditions, as determined by bioclimatic comfort assessments, are important. Bioclimatic components such as temperature, relative humidity, and wind speeds are important in evaluating bioclimatic comfort. In this study of the climate of Kastamonu province, the most suitable areas in terms of bioclimatic comfort have been identified. In this context, climate values belonging to the province of Kastamonu are taken from a total of nine meteorological stations. Altitude (36-1050 m) between stations is noted for revealing climatic changes. The data collected from these stations, including average temperature, relative humidity, and wind speed values are transferred to geographical information system (GIS) using ArcMap 10.2.2 software. GIS maps created from the imported data has designated the most suitable comfort areas in and around the city of Kastamonu. As a result, the study shows that Kastamonu has suitable ranges for bioclimatic comfort zone. The range of bioclimatic comfort value for Kastamonu is 17.6 °C. It is between a comfort ranges which is 15-20 °C. Kastamonu City has suitable area for bioclimatic comfort. PMID:26400090

  1. Determining the bioclimatic comfort in Kastamonu City.

    PubMed

    Cetin, Mehmet

    2015-10-01

    Bioclimatic comfort defines the optimal climatic conditions in which people feel healthy and dynamic. Bioclimatic comfort mapping methods are useful to urban managers and planners. For the purposes of planning, climatic conditions, as determined by bioclimatic comfort assessments, are important. Bioclimatic components such as temperature, relative humidity, and wind speeds are important in evaluating bioclimatic comfort. In this study of the climate of Kastamonu province, the most suitable areas in terms of bioclimatic comfort have been identified. In this context, climate values belonging to the province of Kastamonu are taken from a total of nine meteorological stations. Altitude (36-1050 m) between stations is noted for revealing climatic changes. The data collected from these stations, including average temperature, relative humidity, and wind speed values are transferred to geographical information system (GIS) using ArcMap 10.2.2 software. GIS maps created from the imported data has designated the most suitable comfort areas in and around the city of Kastamonu. As a result, the study shows that Kastamonu has suitable ranges for bioclimatic comfort zone. The range of bioclimatic comfort value for Kastamonu is 17.6 °C. It is between a comfort ranges which is 15-20 °C. Kastamonu City has suitable area for bioclimatic comfort.

  2. Laboratory evaluation of an OTT acoustic digital current meter and a SonTek Laboratory acoustic Doppler velocimeter

    USGS Publications Warehouse

    Vermeyen, T.B.; Oberg, Kevin A.; Jackson, Patrick Ryan

    2009-01-01

    Recently, an acoustic current meter known as the OTT * acoustic digital current meter (ADC) was introduced as an alternative instrument for stream gaging measurements. The Bureau of Reclamation and the U.S. Geological Survey collaborated on a side- by-side evaluation of the ADC and a SonTek/YSI acoustic Doppler velocimeter (ADV). Measurements were carried out in a laboratory flume to evaluate the performance characteristics of the ADC under a range of flow and boundary conditions. The flume contained a physical model of a mountain river with a diversion dam and variety of bed materials ranging from smooth mortar to a cobble bed. The instruments were installed on a trolley system that allowed them to be easily moved within the flume while maintaining a consistent probe orientation. More than 50 comparison measurements were made in an effort to verify the manufacturer’s performance specifications and to evaluate potential boundary disturbance for near-bed and vertical boundary measurements. Data and results from this evaluation are presented and discussed. 

  3. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customer's aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facility's available acoustic power capability becomes maximized with the test-article installed during the actual test then the customer's environment requirement may become compromised. In order to understand the risk of not achieving the customer's in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Station's Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  4. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption during Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customers aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facilitys available acoustic power capability becomes maximized with the test-article installed during the actual test then the customers environment requirement may become compromised. In order to understand the risk of not achieving the customers in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Stations Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  5. Auralization studies on talker comfort

    NASA Astrophysics Data System (ADS)

    Shearer, Jessica; Torres, Rendell R.

    2003-10-01

    Although much research has focused on determining optimal acoustical environments for students in classrooms, relatively little has addressed the classroom as an acoustical workspace for teachers, who may suffer from stress and vocal strain due in part to poor acoustical environments. Although the primary problem is typically the background noise level (whether due to ventilation or students), it is also interesting to study systematically how controlling early reflections may improve the audible ``room response'' at the teacher's speaking location without inordinately increasing the reverberant level of the background noise. Moreover, the room response at the talker's position may help reduce the perceived need to strain the voice, as long as the reflections are not so delayed as to be disturbing. In this study approximately ten configurations of absorptive and reflective surfaces in a ``typical-sized'' classroom are auralized in real time. For each room condition, subjects rate the ``talker comfort'' in terms of perceived loudness of their speech, possible disturbance from echoes or increased background noise, and other factors. The primary descriptive physical parameter is essentially the relative amplitude and delay of clusters of early reflections, which are not always well characterized by the classical room-acoustics descriptors. Initial results of the modeling and subject testing will be presented.

  6. Simplified Ride-Comfort Program

    NASA Technical Reports Server (NTRS)

    Leatherwood, J. D.; Barker, L. M.

    1986-01-01

    Vibration and noise contributions to discomfort quantified. RIDEQUL estimates passenger ride comfort within air- and surface-transportion systems. Provides engineers with reliable method of objectively predicting and evaluating vehicle ride quality. Transforms individual elements of noise and vibration characteristics of vehicle into subjective units and combines these units to produce single discomfort index. Program written in FORTRAN 77 for interactive or batch execution.

  7. Robotic comfort zones

    NASA Astrophysics Data System (ADS)

    Likhachev, Maxim; Arkin, Ronald C.

    2000-10-01

    The paper investigates how the psychological notion of comfort can be useful in the design of robotic systems. A review of the existing study of human comfort, especially regarding its presence in infants, is conducted with the goal being to determine the relevant characteristics for mapping it onto the robotics domain. Focus is place on the identification of the salient features in the environment that affect the comfort level. Factors involved include current state familiarity, working conditions, the amount and location of available resources, etc. As part of our newly developed comfort function theory, the notion of an object as a psychological attachment for a robot is also introduced, as espoused in Bowlby's theory of attachment. The output space of the comfort function and its dependency on the comfort level are analyzed. The results of the derivation of this comfort function are then presented in terms of the impact they have on robotic behavior. Justification for the use of the comfort function are then presented in terms of the impact they have on robotic behavior. Justification for the use of the comfort function in the domain of robotics is presented with relevance for real-world operations. Also, a transformation of the theoretical discussion into a mathematical framework suitable for implementation within a behavior-based control system is presented. The paper concludes with results of simulation studies and real robot experiments using the derived comfort function.

  8. Selected Sports Bras: Overall Comfort and Support.

    ERIC Educational Resources Information Center

    Lawson, LaJean; Lorentzen, Deana

    This study evaluated currently marketed sports bras on subjective measures of comfort and support both within an entire group of women and within cup sizes, correlated the subjective measures of comfort and support with previously reported biomechanical findings of support on the same bras, and further developed empirically based guidelines for…

  9. New methods for evaluating physical and thermal comfort properties of orthotic materials used in insoles for patients with diabetes.

    PubMed

    Lo, Wai Ting; Yick, Kit Lun; Ng, Sun Pui; Yip, Joanne

    2014-01-01

    Orthotic insoles are commonly used in the treatment of the diabetic foot to prevent ulcerations. Choosing suitable insole material is vital for effective foot orthotic treatment. We examined seven types of orthotic materials. In consideration of the key requirements and end uses of orthotic insoles for the diabetic foot, including accommodation, cushioning, and control, we developed test methods for examining important physical properties, such as force reduction and compression properties, insole-skin friction, and shear properties, as well as thermal comfort properties of fabrication materials. A novel performance index that combines various material test results together was also proposed to quantify the overall performance of the insole materials. The investigation confirms that the insole-sock interface has a lower coefficient of friction and shearing stress than those of the insole-skin interface. It is also revealed that material brand and the corresponding density and cell volume, as well as thickness, are closely associated with the performance of moisture absorption and thermal comfort. On the basis of the proposed performance index, practitioners can better understand the properties and performance of various insole materials, thus prescribing suitable orthotic insoles for patients with diabetic foot.

  10. The acoustical design of vehicles-a challenge for qualitative evaluation

    NASA Astrophysics Data System (ADS)

    Schulte-Fortkamp, Brigitte; Genuit, Klaus; Fiebig, Andre

    2005-09-01

    Whenever the acoustical design of vehicles is explored, the crucial question about the appropriate method of evaluation arises. Research shows that not only acoustic but also non-acoustic parameters have a major influence on the way sounds are evaluated. Therefore, new methods of evaluation have to be implemented. Methods are needed which give the opportunity to test the quality of the given ambience and to register the effects and evaluations in their functional interdependence as well as the influence of personal and contextual factors. Moreover, new methods have to give insight into processes of evaluation and their contextual parameters. In other words, the task of evaluating acoustical ambiences consists of designating a set of social, psychological, and cultural conditions which are important to determine particular individual and collective behavior, attitudes, and also emotions relative to the given ambience. However, no specific recommendations exist yet which comprise particular descriptions of how to assess those specific sound effects. That is why there is a need to develop alternative methods of evaluation with whose help effects of acoustical ambiences can be better predicted. A method of evaluation will be presented which incorporates a new sensitive approach for the evaluation of vehicle sounds.

  11. An evaluation of linear acoustic theory for a hovering rotor

    NASA Technical Reports Server (NTRS)

    Morris, C. E. K., Jr.; Farassat, F.; Nystrom, P. A.

    1979-01-01

    Linear acoustic calculations are compared with previously reported data for a small-scale hovering rotor operated at high tip Mach numbers. A detailed calculated description of the distributions of blade surface pressure and shear stress due to skin friction is presented. The noise due to skin friction and loading, in the rotor disk plane, is small compared to thickness noise. The basic conclusions of Boxwell et al about the importance of nonlinear effects are upheld. Some approximations involved in the current theories for the inclusion of nonlinear effects are discussed. Using a model nonlinear problem, it is shown that to use the acoustic analogy, good knowledge of the flowfield is required.

  12. Understanding the adaptive approach to thermal comfort

    SciTech Connect

    Humphreys, M.A.; Nicol, J.F.

    1998-10-01

    This paper explains the adaptive approach to thermal comfort, and an adaptive model for thermal comfort is presented. The model is an example of a complex adaptive system (Casti 1996) whose equilibria are determined by the restrictions acting upon it. People`s adaptive actions are generally effective in securing comfort, which occurs at a wide variety of indoor temperatures. These comfort temperatures depend upon the circumstances in which people live, such as the climate and the heating or cooling regime. The temperatures may be estimated from the mean outdoor temperature and the availability of a heating or cooling plant. The evaluation of the parameters of the adaptive model requires cross-sectional surveys to establish current norms and sequential surveys (with and without intervention) to evaluate the rapidity of people`s adaptive actions. Standards for thermal comfort will need revision in the light of the adaptive approach. Implications of the adaptive model for the HVAC industry are noted.

  13. Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An activated carbon fiber nonwoven (ACF) was manufactured from cotton nonowoven fabric. For the ACF acoustical application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glass fiber ...

  14. Acoustical Evaluation of Carbonized and Activated Cotton Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The process of manufacturing a carbonized and activated nonwoven made by cotton fiber was investigated in this paper. The study was focused on the acoustic application and nonwoven composites with cotton nonwoven as a base layer and glass fiber nonwoven, cotton nonwoven, and carbonized and activated...

  15. Use of acoustic monitoring system for debris flow discharge evaluation

    NASA Astrophysics Data System (ADS)

    Galgaro, A. G.; Tecca, P. R.; Genevois, R.; Deganutti, A. M.

    2003-04-01

    In 1997 an automated system for monitoring of debris flows has been installed in the Acquabona channel Dolomites, Italy. Induction geophones, with a specific frequency of 10 Hz, measure the amplitude of vertical ground vibrations generated by the passage of a flowing mass along the channel. Continuous acoustic logs and ultrasonic hydrograph recorded at the lower-channel measurement station for the debris flow of August 17, 1998, show a striking correspondence. This correspondence, already observed in different flow sites, is represented by the best fit between flow depth and flow sensor amplitude. Average front velocity for surges, calculated from the signal peak time shift and the distance between the sensors along the flow path, range between 2.00 and 7.7 m/s. As the ultrasonic sensor provides a way to measure the variation of the flow section area with the flow depth, the debris flow peak discharge may be estimated; obtained values of debris flow peak discharge range from 4 and 30 m3/s. Volumes were calculated by integrating instantaneous discharges through the hydrograph and by integrating the geophone log (acoustic flux). Volumes of 13700 m3 and 15500 m3 have been respectively obtained. The slight difference between the two values may result from the fact that acoustic records: i) are sensitive to the high frequencies, typical of the debris flow tails; ii) sum up the contributions sent by the whole flowing mass, while the ecometer detect the flow depth at every time at only one section. As a consequence the rising of the whole geophone log gives a higher value at the integration result. This only acoustic system can give a reasonably proxy for discharge and total volumes involved, which are among the most important parameters for debris flow hazard assessment and planning countermeasures. This methodology can be used in other debris flow sites if they are calibrated by the acoustic characterization of debris, obtained by both seismic surveys and SPT tests, and

  16. Acoustic diagnosis for nondestructive evaluation of ceramic coatings on steel substrates

    SciTech Connect

    Aizawa, Tatsuhiko; Kihara, Junji; Ito, Manabu

    1995-11-01

    New methodology is proposed and developed to make quantitative nondestructive evaluation of TiN coated SKH steel substrates. Since the measured acoustic structure is in precise correspondence with the multi-layered elastic media, change of elastic properties by degradation and damage can be easily distinguished by the acoustic spectro microscopy. In particular, rather complex acoustic structure can be measured by the present method for ceramic coated steel substrate system, but it is completely described by the two-layer model in two dimensional elasticity. Typical example is the cut-off phenomenon where the dispersion curve for the leaky surface wave velocity is forced to be terminated by alternative activation of shear wave instead of it. The quantitative nondestructive diagnosis was developed on the basis of this predictable acoustic structure. Furthermore, the effect of coating conditions on the acoustic structure is also discussed to make residual stress distribution analysis in coating by the acoustic spectro microscopy with reference to the X-ray stress analysis. Some comments are made on further advancement of the present acoustic spectro microscopy adaptive to precise characterization of ceramic coatings and practical sensing system working in practice.

  17. Evaluation of the biomechanics of atherosclerosis by acoustic microscopy

    NASA Astrophysics Data System (ADS)

    Saijo, Yoshifumi; Nitta, Shin-ichi; Schiott Jorgensen, Claus; Falk, Erling

    2001-07-01

    Acoustic microscopy provides not only the morphology, but also the biomechanical properties of the biological soft tissues. The biomechanics of atherosclerosis is important because the pathophysiology of atherosclerosis is closely related with mechanical properties and mechanical stress. Rupture of the fibrous cap of atheromatous plaque is the initial event in acute coronary syndrome such as acute myocardial infarction or unstable angina. In addition to extrinsic physical stresses to the plaque, the intrinsic biomechanical property of the plaque is important for assessing the mechanism of the rupture. Two sets of SAMs operating in 100 to 200 MHz and in 800 MHz to 1.3 GHz were equipped to measure the acoustic properties of atherosclerosis of human or mouse arteries. The values of attenuation and sound speed in the tissue components of atherosclerosis were measured by analyzing the frequency dependent characteristics of the amplitude and phase signals. Both values were highest in calcification and lowest in lipid pool. Although attenuation and sound speed were relatively high in intimal fibrosis, the inhomogeneity of acoustic parameters was found within the fibrous cap. Polarized microscopy for the collagen stained with Picrosirius red showed that the attenuation of ultrasound was significantly higher in type I collagen with orange polarized color compared to type III collagen with green color. SAM has shown the possibility to detect the plaque vulnerability and it might improve our understanding of the sudden rupture from micro-mechanical point of view.

  18. The Comparative Evaluation of Patient’s Satisfaction and Comfort Level by Diode Laser and Scalpel in the Management of Mucogingival Anomalies

    PubMed Central

    Jain, Garima; Dhodapkar, Shrikant Vishnu; Kumathalli, Kanteshwari Iranagouda; Jaiswal, Gagan

    2015-01-01

    Background Surgical correction of mucogingival anomalies is required to enhance patient’s compatibility to maintain oral hygiene or to improve facial aesthetics or both. Laser has become a desirable and dependable alternative for traditional surgical techniques because it is simple and painless with more predictable outcomes. Aim The aim of this study was to compare the effects of the conventional scalpel technique and the laser technique on the degree of discomfort, satisfaction, healing and postoperative pain experienced by patients after correction of mucogingival anomalies. Materials and Methods In the present study 70 patients were enrolled and randomly distributed in two groups i.e. surgical correction of mucogingival anomalies by scalpel and by laser. Patient’s comfort level, pain and satisfaction level was assessed by using Visual analogue scale (VAS) and healing was evaluated by healing index. Results The results indicated patients treated with the diode laser had less postoperative pain and discomfort with remarkable satisfactory results and healing compared to patients treated with the conventional technique. Conclusion Laser is a desirable therapeutic alternative to correct soft tissue anomalies. It allows good control of haemorrhage with comfortable healing phase and appreciable satisfactory outcomes. PMID:26557618

  19. Thermal comfort following immersion.

    PubMed

    Guéritée, Julien; Redortier, Bernard; House, James R; Tipton, Michael J

    2015-02-01

    Unlike thermal comfort in air, little research has been undertaken exploring thermal comfort around water sports. We investigated the impact of swimming and cooling in air after swimming on thermal comfort. After 10 min of swimming-and-resting cycles in 28°C water, volunteers wearing two types of garments or in swim briefs, faced winds in 24°C air, at rest or when stepping. Thermal comfort was significantly higher during swimming than resting. Post-immersion, following maximum discomfort, in 45 of 65 tests thermal comfort improved although mean skin temperature was still cooling (0.26 [SD 0.19] °C·min(-1) - max was 0.89°C·min(-1)). When thermal comfort was re-established mean skin temperature was lower than at maximal discomfort in 39 of 54 tests (0.81 [SD 0.58] °C - max difference was 2.68°C). The reduction in thermal discomfort in this scenario could be due to the adaptation of thermoreceptors, or to reductions in cooling rates to levels where discomfort was less stimulated. The relief from the recent discomfort may explain why, later, thermal comfort returned to initial levels in spite of poorer thermal profiles.

  20. Evaluation of the successive approximations method for acoustic streaming numerical simulations.

    PubMed

    Catarino, S O; Minas, G; Miranda, J M

    2016-05-01

    This work evaluates the successive approximations method commonly used to predict acoustic streaming by comparing it with a direct method. The successive approximations method solves both the acoustic wave propagation and acoustic streaming by solving the first and second order Navier-Stokes equations, ignoring the first order convective effects. This method was applied to acoustic streaming in a 2D domain and the results were compared with results from the direct simulation of the Navier-Stokes equations. The velocity results showed qualitative agreement between both methods, which indicates that the successive approximations method can describe the formation of flows with recirculation. However, a large quantitative deviation was observed between the two methods. Further analysis showed that the successive approximation method solution is sensitive to the initial flow field. The direct method showed that the instantaneous flow field changes significantly due to reflections and wave interference. It was also found that convective effects contribute significantly to the wave propagation pattern. These effects must be taken into account when solving the acoustic streaming problems, since it affects the global flow. By adequately calculating the initial condition for first order step, the acoustic streaming prediction by the successive approximations method can be improved significantly.

  1. Evaluation of the successive approximations method for acoustic streaming numerical simulations.

    PubMed

    Catarino, S O; Minas, G; Miranda, J M

    2016-05-01

    This work evaluates the successive approximations method commonly used to predict acoustic streaming by comparing it with a direct method. The successive approximations method solves both the acoustic wave propagation and acoustic streaming by solving the first and second order Navier-Stokes equations, ignoring the first order convective effects. This method was applied to acoustic streaming in a 2D domain and the results were compared with results from the direct simulation of the Navier-Stokes equations. The velocity results showed qualitative agreement between both methods, which indicates that the successive approximations method can describe the formation of flows with recirculation. However, a large quantitative deviation was observed between the two methods. Further analysis showed that the successive approximation method solution is sensitive to the initial flow field. The direct method showed that the instantaneous flow field changes significantly due to reflections and wave interference. It was also found that convective effects contribute significantly to the wave propagation pattern. These effects must be taken into account when solving the acoustic streaming problems, since it affects the global flow. By adequately calculating the initial condition for first order step, the acoustic streaming prediction by the successive approximations method can be improved significantly. PMID:27250122

  2. The Rigidity and Comfort of Habits: A Cultural and Philosophical Analysis of the Ups and Downs of Mainstreaming Evaluation.

    ERIC Educational Resources Information Center

    Grudens-Schuck, Nancy

    Mainstreaming evaluation requires establishing aesthetic and ethical frameworks, as well as knowledge and skills, that make "doing" evaluation seem like the right thing. Evaluators and others have worked hard to institute evaluation as a prudent activity for society to support. The phenomenon of mainstreaming itself, however, poses challenges to…

  3. Surface Roughness Evaluation Based on Acoustic Emission Signals in Robot Assisted Polishing

    PubMed Central

    de Agustina, Beatriz; Marín, Marta María; Teti, Roberto; Rubio, Eva María

    2014-01-01

    The polishing process is the most common technology used in applications where a high level of surface quality is demanded. The automation of polishing processes is especially difficult due to the high level of skill and dexterity that is required. Much of this difficulty arises because of the lack of reliable data on the effect of the polishing parameters on the resulting surface roughness. An experimental study was developed to evaluate the surface roughness obtained during Robot Assisted Polishing processes by the analysis of acoustic emission signals in the frequency domain. The aim is to find out a trend of a feature or features calculated from the acoustic emission signals detected along the process. Such an evaluation was made with the objective of collecting valuable information for the establishment of the end point detection of polishing process. As a main conclusion, it can be affirmed that acoustic emission (AE) signals can be considered useful to monitor the polishing process state. PMID:25405509

  4. Computer Evaluation Of Real-Time X-Ray And Acoustic Images

    NASA Astrophysics Data System (ADS)

    Jacoby, M. H.; Loe, R. S.; Dondes, P. A.

    1983-03-01

    The weakest link in the inspection process is the subjective interpretation of data by inspectors. To overcome this troublesome fact computer based analysis systems have been developed. In the field of nondestructive evaluation (NDE) there is a large class of inspections that can benefit from computer analysis. X-ray images (both film and fluoroscopic) and acoustic images lend themselves to automatic analysis as do the one-dimensional signals associated with ultrasonic, eddy current and acoustic emission testing. Computer analysis can enhance and evaluate subtle details. Flaws can be located and measured, and accept-ance decisions made by computer in a consistent and objective manner. This paper describes the interactive, computer-based analysis of real-time x-ray images and acoustic images of graphite/epoxy adhesively bonded structures.

  5. Surface roughness evaluation based on acoustic emission signals in robot assisted polishing.

    PubMed

    de Agustina, Beatriz; Marín, Marta María; Teti, Roberto; Rubio, Eva María

    2014-11-14

    The polishing process is the most common technology used in applications where a high level of surface quality is demanded. The automation of polishing processes is especially difficult due to the high level of skill and dexterity that is required. Much of this difficulty arises because of the lack of reliable data on the effect of the polishing parameters on the resulting surface roughness. An experimental study was developed to evaluate the surface roughness obtained during Robot Assisted Polishing processes by the analysis of acoustic emission signals in the frequency domain. The aim is to find out a trend of a feature or features calculated from the acoustic emission signals detected along the process. Such an evaluation was made with the objective of collecting valuable information for the establishment of the end point detection of polishing process. As a main conclusion, it can be affirmed that acoustic emission (AE) signals can be considered useful to monitor the polishing process state.

  6. Acoustic emission evaluation of plasma-sprayed thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Berndt, C. C.

    1984-01-01

    Acoustic emission techniques have recently been used in a number of studies to investigate the performance and failure behavior of plasma-sprayed thermal barrier coatings. Failure of the coating is a complex phenomena, especially when the composite nature of the coating is considered in the light of possible failure mechanisms. Thus it can be expected that both the metal and ceramic components (i.e., the bond coat and ceramic overlay) of a composite thermal protection system influence the macroscopic behavior and performance of the coating. The aim of the present work is to summarize the 'state-of-the-art' in terms of this initial work and indicate where future progress may be made.

  7. Theoretical evaluation of the acoustic field in an ultrasonic bioreactor.

    PubMed

    Louw, Tobias M; Subramanian, Anuradha; Viljoen, Hendrik J

    2015-06-01

    Ultrasound-assisted bioreactors that provide mechanical conditioning to cells have broad applicability in tissue engineering, but biological experiments with ultrasound are very sensitive to environmental conditions. A mathematical model was developed to complement experimental measurements, as well as to describe ultrasonic fields existing in regions where measurements are impossible, specifically, within microporous tissue engineering scaffolds. The model uniquely combines Biot theory to predict the ultrasonic field in the scaffold with an electromechanical transducer model to couple the mechanical stimulation experienced by cells to the external electrical input. In the specific example examined here, cells immobilized on scaffolds are subjected to different forms of ultrasonic stimulation due to the formation of standing wave fields and vertical high-pressure bands. The model confirms the sensitivity of the supplied acoustic power to the liquid level in sonobioreactors and identifies the input electrical impedance as a method of detecting resonance effects.

  8. Acoustical evaluation of carbonized and activated cotton nonwovens.

    PubMed

    Jiang, N; Chen, J Y; Parikh, D V

    2009-12-01

    An activated carbon fiber nonwoven (ACF) was manufactured from a cotton nonwoven fabric. For the ACF acoustic application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glassfiber nonwoven, and the cotton nonwoven base layer with a layer of cotton fiber nonwoven. Their noise absorption coefficients and sound transmission loss were measured using the Brüel and Kjaer impedance tube instrument. Statistical significance of the differences between the composites was tested using the method of Duncan's grouping. The study concluded that the ACF composite exhibited a greater ability to absorb normal incidence sound waves than the composites with either glassfiber or cotton fiber. The analysis of sound transmission loss revealed that the three composites still obeyed the mass law of transmission loss. The composite with the surface layer of cotton fiber nonwoven possessed a higher fabric density and therefore showed a better sound insulation than the composites with glassfiber and ACF. PMID:19664919

  9. Acoustical evaluation of carbonized and activated cotton nonwovens.

    PubMed

    Jiang, N; Chen, J Y; Parikh, D V

    2009-12-01

    An activated carbon fiber nonwoven (ACF) was manufactured from a cotton nonwoven fabric. For the ACF acoustic application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glassfiber nonwoven, and the cotton nonwoven base layer with a layer of cotton fiber nonwoven. Their noise absorption coefficients and sound transmission loss were measured using the Brüel and Kjaer impedance tube instrument. Statistical significance of the differences between the composites was tested using the method of Duncan's grouping. The study concluded that the ACF composite exhibited a greater ability to absorb normal incidence sound waves than the composites with either glassfiber or cotton fiber. The analysis of sound transmission loss revealed that the three composites still obeyed the mass law of transmission loss. The composite with the surface layer of cotton fiber nonwoven possessed a higher fabric density and therefore showed a better sound insulation than the composites with glassfiber and ACF.

  10. Acoustical Evaluation of the NASA Langley V/STOL Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Ver, I. L.

    1976-01-01

    The results are presented of the acoustical measurements made to supply NASA Langley operating personnel with the acoustical characteristics of the tunnel test section needed for the planning of acoustical measurements and to identify the major noise sources. The results of the preliminary measurements of the spatial distribution of the sound field in the closed tunnel configuration indicate that the total sound power output of an unknown sound source placed in the test section could most probably be evaluated by measuring the sound pressure in two properly chosen locations in the duct - one upstream and one downstream of the test section. However, it is recommended that the practicability of this method of sound power output measurements be further investigated, preferably in a small scale model of the V/STOL Tunnel.

  11. Evaluation of multiple-frequency, active and passive acoustics as surrogates for bedload transport

    USGS Publications Warehouse

    Wood, Molly S.; Fosness, Ryan L.; Pachman, Gregory; Lorang, Mark; Tonolla, Diego

    2015-01-01

    The use of multiple-frequency, active acoustics through deployment of acoustic Doppler current profilers (ADCPs) shows potential for estimating bedload in selected grain size categories. The U.S. Geological Survey (USGS), in cooperation with the University of Montana (UM), evaluated the use of multiple-frequency, active and passive acoustics as surrogates for bedload transport during a pilot study on the Kootenai River, Idaho, May 17-18, 2012. Four ADCPs with frequencies ranging from 600 to 2000 kHz were used to measure apparent moving bed velocities at 20 stations across the river in conjunction with physical bedload samples. Additionally, UM scientists measured the sound frequencies of moving particles with two hydrophones, considered passive acoustics, along longitudinal transects in the study reach. Some patterns emerged in the preliminary analysis which show promise for future studies. Statistically significant relations were successfully developed between apparent moving bed velocities measured by ADCPs with frequencies 1000 and 1200 kHz and bedload in 0.5 to 2.0 mm grain size categories. The 600 kHz ADCP seemed somewhat sensitive to the movement of gravel bedload in the size range 8.0 to 31.5 mm, but the relation was not statistically significant. The passive hydrophone surveys corroborated the sample results and could be used to map spatial variability in bedload transport and to select a measurement cross-section with moving bedload for active acoustic surveys and physical samples.

  12. Evaluation of Parallel-Element, Variable-Impedance, Broadband Acoustic Liner Concepts

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Howerton, Brian M.; Ayle, Earl

    2012-01-01

    Recent trends in aircraft engine design have highlighted the need for acoustic liners that provide broadband sound absorption with reduced liner thickness. Three such liner concepts are evaluated using the NASA normal incidence tube. Two concepts employ additive manufacturing techniques to fabricate liners with variable chamber depths. The first relies on scrubbing losses within narrow chambers to provide acoustic resistance necessary for sound absorption. The second employs wide chambers that provide minimal resistance, and relies on a perforated sheet to provide acoustic resistance. The variable-depth chambers used in both concepts result in reactance spectra near zero. The third liner concept employs mesh-caps (resistive sheets) embedded at variable depths within adjacent honeycomb chambers to achieve a desired impedance spectrum. Each of these liner concepts is suitable for use as a broadband sound absorber design, and a transmission line model is presented that provides good comparison with their respective acoustic impedance spectra. This model can therefore be used to design acoustic liners to accurately achieve selected impedance spectra. Finally, the effects of increasing the perforated facesheet thickness are demonstrated, and the validity of prediction models based on lumped element and wave propagation approaches is investigated. The lumped element model compares favorably with measured results for liners with thin facesheets, but the wave propagation model provides good comparisons for a wide range of facesheet thicknesses.

  13. Guide to Setting Thermal Comfort Criteria and Minimizing Energy Use in Delivering Thermal Comfort

    SciTech Connect

    Regnier, Cindy

    2012-08-31

    Historically thermal comfort in buildings has been controlled by simple dry bulb temperature settings. As we move into more sophisticated low energy building systems that make use of alternate systems such as natural ventilation, mixed mode system and radiant thermal conditioning strategies, a more complete understanding of human comfort is needed for both design and control. This guide will support building designers, owners, operators and other stakeholders in defining quantifiable thermal comfort parameters?these can be used to support design, energy analysis and the evaluation of the thermal comfort benefits of design strategies. This guide also contains information that building owners and operators will find helpful for understanding the core concepts of thermal comfort. Whether for one building, or for a portfolio of buildings, this guide will also assist owners and designers in how to identify the mechanisms of thermal comfort and space conditioning strategies most important for their building and climate, and provide guidance towards low energy design options and operations that can successfully address thermal comfort. An example of low energy design options for thermal comfort is presented in some detail for cooling, while the fundamentals to follow a similar approach for heating are presented.

  14. Vibro-acoustic analysis procedures for the evaluation of the sound insulation characteristics of agricultural machinery cabins

    NASA Astrophysics Data System (ADS)

    Desmet, W.; Pluymers, B.; Sas, P.

    2003-09-01

    Over the last few years, customer demands regarding acoustic performance, along with the tightening of legal regulations on noise emission levels and human exposure to noise, have made the noise and vibration properties into important design criteria for agricultural machinery cabins. In this framework, both experimental analysis procedures for prototype testing as well as reliable numerical prediction tools for early design assessment are compulsory for an efficient optimization of the cabin noise and vibration comfort. This paper discusses several numerical approaches, which are based on the finite element and boundary element method, in terms of their practical use for airborne sound insulation predictions. To illustrate the efficiency and reliability of the various vibro-acoustic analysis procedures, the numerical procedures are applied for the case of a harvester driver's cabin and validated with experimental results.

  15. Bringing comfort to Haiti.

    PubMed

    Wegner, Ronald A; Boal, Alex; Walters, Lynda; Thomas, Tim; Wells, Erica; Griswold, Jeremy; Oravec, David G

    2010-01-01

    On January 12, 2010, a devastating earthquake ravaged one of the poorest nations in the western hemisphere. A week later, the U.S. Naval Ship Comfort was anchored off Port-au-Prince to perform a mission of mercy for hundreds of critically injured victims of this disaster. The staff of the U.S. Naval Ship Comfort included military as well as civilian volunteer healthcare professionals, working as a team day and night under adverse conditions to save lives and optimize outcomes for the survivors.

  16. Comparative evaluation of test methods to simulate acoustic response of shroud-enclosed spacecraft structures

    NASA Technical Reports Server (NTRS)

    On, F. J.

    1975-01-01

    Test methods were evaluated to ascertain whether a spacecraft, properly tested within its shroud, could be vibroacoustic tested without the shroud, with adjustments made in the acoustic input spectra to simulate the acoustic response of the missing shroud. The evaluation was based on vibroacoustic test results obtained from a baseline model composed (1) of a spacecraft with adapter, lower support structure, and shroud; (2) of the spacecraft, adapter, and lower structure, but without the shroud; and (3) of the spacecraft and adapter only. Emphasis was placed on the magnitude of the acoustic input changes required to substitute for the shroud and the difficulty of making such input changes, and the degree of missimulation which can result from the performance of a particular, less-than optimum test. Conclusions are drawn on the advantages and disadvantages derived from the use of input spectra adjustment methods and lower support structure simulations. Test guidelines were also developed for planning and performing a launch acoustic-environmental test.

  17. Evaluation of Midwater Trawl Selectivity and its Influence on Acoustic-Based Fish Population Surveys

    NASA Astrophysics Data System (ADS)

    Williams, Kresimir

    Trawls are used extensively during fisheries abundance surveys to derive estimates of fish density and, in the case of acoustic-based surveys, to identify acoustically sampled fish populations. However, trawls are selective in what fish they retain, resulting in biased estimates of density, species, and size compositions. Selectivity of the midwater trawl used in acoustic-based surveys of walleye pollock (Theragra chalcogramma) was evaluated using multiple methods. The effects of trawl selectivity on the acoustic-based survey abundance estimates and the stock assessment were evaluated for the Gulf of Alaska walleye pollock population. Selectivity was quantified using recapture, or pocket, nets attached to the outside of the trawl. Pocket net catches were modeled using a hierarchical Bayesian model to provide uncertainty in selectivity parameter estimates. Significant under-sampling of juvenile pollock by the midwater trawl was found, with lengths at 50% retention ranging from 14--26 cm over three experiments. Escapement was found to be light dependent, with more fish escaping in dark conditions. Highest escapement rates were observed in the aft of the trawl near to the codend though the bottom panel of the trawl. The behavioral mechanisms involved in the process of herding and escapement were evaluated using stereo-cameras, a DIDSON high frequency imaging sonar, and pocket nets. Fish maintained greater distances from the trawl panel during daylight, suggesting trawl modifications such as increased visibility of netting materials may evoke stronger herding responses and increased retention of fish. Selectivity and catchability of pollock by the midwater trawl was also investigated using acoustic density as an independent estimate of fish abundance to compare with trawl catches. A modeling framework was developed to evaluate potential explanatory factors for selectivity and catchability. Selectivity estimates were dependent on which vessel was used for the survey

  18. Comfort measures: a concept analysis.

    PubMed

    Oliveira, Irene

    2013-01-01

    Reference to the concept of comfort measures is growing in the nursing and medical literature; however, the concept of comfort measures is rarely defined. For the comfort work of nurses to be recognized, nurses must be able to identify and delineate the key attributes of comfort measures. A concept analysis using Rodgers' evolutionary method (2000) was undertaken with the goal of identifying the core attributes of comfort measures and thereby clarifying this concept. Health care literature was accessed from the CINAHL and PubMed databases. No restrictions were placed on publication dates. Four main themes of attributes for comfort measures were identified during the analysis. Comfort measures involve an active, strategic process including elements of "stepping in" and "stepping back," are both simple and complex, move from a physical to a holistic perspective and are a part of supportive care. The antecedents to comfort measures are comfort needs and the most common consequence of comfort measures is enhanced comfort. Although the concept of comfort measures is often associated with end-of-life care, this analysis suggests that comfort measures are appropriate for nursing care in all settings and should be increasingly considered in the clinical management of patients who are living with multiple, chronic comorbidities.

  19. The Reliability and Validity of the Comfort Level Method of Setting Hearing Aid Gain

    ERIC Educational Resources Information Center

    Walden, Brian E.; And Others

    1977-01-01

    Investigated in a series of experiments with 40 adults (20- to 70-years-old) having bilateral sensorineural hearing impairments was the test-retest reliability of the comfort level method for setting the acoustic gain of hearing aids, and the relationship between the comfort settings utilized in more realistic daily listening situations.…

  20. Acoustic Treatment Design Scaling Methods. Volume 3; Test Plans, Hardware, Results, and Evaluation

    NASA Technical Reports Server (NTRS)

    Yu, J.; Kwan, H. W.; Echternach, D. K.; Kraft, R. E.; Syed, A. A.

    1999-01-01

    The ability to design, build, and test miniaturized acoustic treatment panels on scale-model fan rigs representative of the full-scale engine provides not only a cost-savings, but an opportunity to optimize the treatment by allowing tests of different designs. To be able to use scale model treatment as a full-scale design tool, it is necessary that the designer be able to reliably translate the scale model design and performance to an equivalent full-scale design. The primary objective of the study presented in this volume of the final report was to conduct laboratory tests to evaluate liner acoustic properties and validate advanced treatment impedance models. These laboratory tests include DC flow resistance measurements, normal incidence impedance measurements, DC flow and impedance measurements in the presence of grazing flow, and in-duct liner attenuation as well as modal measurements. Test panels were fabricated at three different scale factors (i.e., full-scale, half-scale, and one-fifth scale) to support laboratory acoustic testing. The panel configurations include single-degree-of-freedom (SDOF) perforated sandwich panels, SDOF linear (wire mesh) liners, and double-degree-of-freedom (DDOF) linear acoustic panels.

  1. Coupled acoustic-gravity field for dynamic evaluation of ion exchange with a single resin bead.

    PubMed

    Kanazaki, Takahiro; Hirawa, Shungo; Harada, Makoto; Okada, Tetsuo

    2010-06-01

    A coupled acoustic-gravity field is efficient for entrapping a particle at the position determined by its acoustic properties rather than its size. This field has been applied to the dynamic observation of ion-exchange reactions occurring in a single resin bead. The replacement of counterions in an ion-exchange resin induces changes in its acoustic properties, such as density and compressibility. Therefore, we can visually trace the advancement of an ion-exchange reaction as a time change in the levitation position of a resin bead entrapped in the field. Cation-exchange reactions occurring in resin beads with diameters of 40-120 microm are typically completed within 100-200 s. Ion-exchange equilibrium or kinetics is often evaluated with off-line chemical analyses, which require a batch amount of ion exchangers. Measurements with a single resin particle allow us to evaluate ion-exchange dynamics and kinetics of ions including those that are difficult to measure by usual off-line analyses. The diffusion properties of ions in resins have been successfully evaluated from the time change in the levitation positions of resin beads. PMID:20462180

  2. The reliability and validity of the comfort level method of setting hearing aid gain.

    PubMed

    Walden, B E; Schuchman, G I; Sedge, R K

    1977-11-01

    The comfort level method (Carhart, 1946) probably is the most widely used procedure for setting the acoustic gain of hearing aids. A series of experiments were conducted to determine the test-retest reliability of the comfort level method and the relationship between the comfort settings established in a clinical test suite and the comfort settings utilized in more realistic daily listening situations. Adults with bilateral sensorineural hearing impairments were subjects. The results suggest that the comfort level method has good test-retest reliability for most clinical purposes. Further, clinically established comfort settings may accurately represent typical daily-use settings if the input level used to establish the comfort settings in the clinical environment is 70 dB SPL.

  3. Nondestructive evaluation of explosively welded clad rods by resonance acoustic spectroscopy.

    PubMed

    Fan, Y; Tysoe, B; Sim, J; Mirkhani, K; Sinclair, A N; Honarvar, F; Sildva, Harry; Szecket, Alexander; Hardwick, Roy

    2003-07-01

    A resonance acoustic spectroscopy technique is assessed for nondestructive evaluation of explosively welded clad rods. Each rod is modeled as a two-layered cylinder with a spring-mass system to represent a thin interfacial layer containing the weld. A range of interfacial profiles is generated in a set of experimental samples by varying the speed of the explosion that drives the copper cladding into the aluminum core. Excellent agreement is achieved between measured and calculated values of the resonant frequencies of the system, through appropriate adjustment of the interfacial mass and spring constants used in the wave scattering calculations. Destructive analysis of the interface in the experimental specimens confirms that key features of the interfacial profile may be inferred from resonance acoustic spectroscopy analysis applied to ultrasonic measurements.

  4. Laser photoacoustic technique for ultrasonic surface acoustic wave velocity evaluation on porcelain

    NASA Astrophysics Data System (ADS)

    Qian, K.; Tu, S. J.; Gao, L.; Xu, J.; Li, S. D.; Yu, W. C.; Liao, H. H.

    2016-10-01

    A laser photoacoustic technique has been developed to evaluate the surface acoustic wave (SAW) velocity of porcelain. A Q-switched Nd:YAG laser at 1064 nm was focused by a cylindrical lens to initiate broadband SAW impulses, which were detected by an optical fiber interferometer with high spatial resolution. Multiple near-field surface acoustic waves were observed on the sample surface at various locations along the axis perpendicular to the laser line source as the detector moved away from the source in the same increments. The frequency spectrum and dispersion curves were obtained by operating on the recorded waveforms with cross-correlation and FFT. The SAW phase velocities of the porcelain of the same source are similar while they are different from those of different sources. The marked differences of Rayleigh phase velocities in our experiment suggest that this technique has the potential for porcelain identification.

  5. Evaluation of Porous Medium Permeability by Acoustic Logging Finds Geothermal Applications

    SciTech Connect

    Conche, B.; Lebreton, F.; Rojas, J.

    1986-01-21

    In a well, after an acoustic waveform has circulated through the surrounding porous media, the study of its alteration can help in evaluating their permeability. The treatment of the acoustic compressional wave's first three cycles yields a unique parameter called I-c. The recording of this I-c log all along any open hole interval is now possible by respecting some practical rules known by logging companies. Large flows of fluid found in geothermal low-enthalpy operations have provided an opportunity to check the validity of this method. Cumulative I-c derived permeability with depth (''EXAFLO'' log) correlates with the flowmeter log, as examples will show. Some new aspects of the theory underlying the I-c/permeability relationship have been developed and are described here.

  6. A Systematic Literature Review Toward the Characterization of Comfort.

    PubMed

    Pinto, Sara; Caldeira, Sílvia; Martins, José Carlos

    2016-01-01

    Comfort integrates the taxonomies and the classifications of nursing knowledge. Its meaning is not yet clear, although it is an important construct from which theories are developed. This article aims to analyze comfort in nursing scientific literature. The results highlight a particular interest in comfort at crisis situations such as illness, palliative care, or intensive care. Comforting seems to be a complex intervention. More studies are needed to achieve its operational assimilation and implementation in clinical practice, as well as the evaluation of its efficiency and effectiveness. PMID:26633722

  7. Performance evaluation of an acoustic indoor localization system based on a fingerprinting technique

    NASA Astrophysics Data System (ADS)

    Aloui, Nadia; Raoof, Kosai; Bouallegue, Ammar; Letourneur, Stephane; Zaibi, Sonia

    2014-12-01

    We present an acoustic location system that adopts the time of arrival of the path of maximum amplitude as a signature and estimates the target position through nonparametric kernel regression. The system was evaluated in experiments for two main configurations: a privacy-oriented configuration with code division multiple access operation and a centralized configuration with time division multiple access operation. The effects of the number and positions of sources on the performance of the privacy-oriented system was studied. Moreover, the effect of the number of fingerprint positions on the performance of both systems was investigated. Results showed that our privacy-oriented scheme provides an accuracy of 8.5 cm with 87% precision, whereas our centralized system provides an accuracy of 2.7 cm for 93% of measurements. A comparison between our privacy-oriented system and another acoustic location system based on code division multiple access operation and lateration was conducted on our test bench and revealed that the cumulative error distribution function of the fingerprint-based system is better than that of the lateration-based system. This result is similar to that found for Wi-Fi radio-based localization. However, our experiments are the first to demonstrate the detrimental effect that reverberation has on naive acoustic localization approaches.

  8. Evaluation of a Variable-Impedance Ceramic Matrix Composite Acoustic Liner

    NASA Technical Reports Server (NTRS)

    Jones, M. G.; Watson, W. R.; Nark, D. M.; Howerton, B. M.

    2014-01-01

    As a result of significant progress in the reduction of fan and jet noise, there is growing concern regarding core noise. One method for achieving core noise reduction is via the use of acoustic liners. However, these liners must be constructed with materials suitable for high temperature environments and should be designed for optimum absorption of the broadband core noise spectrum. This paper presents results of tests conducted in the NASA Langley Liner Technology Facility to evaluate a variable-impedance ceramic matrix composite acoustic liner that offers the potential to achieve each of these goals. One concern is the porosity of the ceramic matrix composite material, and whether this might affect the predictability of liners constructed with this material. Comparisons between two variable-depth liners, one constructed with ceramic matrix composite material and the other constructed via stereolithography, are used to demonstrate this material porosity is not a concern. Also, some interesting observations are noted regarding the orientation of variable-depth liners. Finally, two propagation codes are validated via comparisons of predicted and measured acoustic pressure profiles for a variable-depth liner.

  9. Predicting Human Thermal Comfort in Automobiles

    SciTech Connect

    Rugh, J.; Bharathan, D.; Chaney, L.

    2005-06-01

    The objects of this report are to: (1) increase national energy security by reducing fuel use for vehicle climate control systems; (2) show/demonstrate technology that can reduce the fuel used by LD vehicles' ancillary systems; and (3) develop tools to evaluate the effectiveness of energy-efficient systems including--comfort, cost, practicality, ease-of-use, and reliability.

  10. Evaluation of several non-reflecting computational boundary conditions for duct acoustics

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Zorumski, William E.; Hodge, Steve L.

    1994-01-01

    Several non-reflecting computational boundary conditions that meet certain criteria and have potential applications to duct acoustics are evaluated for their effectiveness. The same interior solution scheme, grid, and order of approximation are used to evaluate each condition. Sparse matrix solution techniques are applied to solve the matrix equation resulting from the discretization. Modal series solutions for the sound attenuation in an infinite duct are used to evaluate the accuracy of each non-reflecting boundary conditions. The evaluations are performed for sound propagation in a softwall duct, for several sources, sound frequencies, and duct lengths. It is shown that a recently developed nonlocal boundary condition leads to sound attenuation predictions considerably more accurate for short ducts. This leads to a substantial reduction in the number of grid points when compared to other non-reflecting conditions.

  11. Aircraft passenger comfort experience: underlying factors and differentiation from discomfort.

    PubMed

    Ahmadpour, Naseem; Robert, Jean-Marc; Lindgaard, Gitte

    2016-01-01

    Previous studies defined passengers' comfort based on their concerns during the flight and a set of eight experiential factors such as 'peace of mind', 'physical wellbeing', 'pleasure', etc. One Objective of this paper was to determine whether the factors underlying the passengers' experience of comfort differ from those of discomfort. Another objective was to cross-validate those factors. In the first study, respondents provided written reports of flight comfort and discomfort experiences separately and gave ratings on the impact of the eight factors on each experience. Follow up interviews were also conducted. Significant difference was found between comfort and discomfort ratings for two factors of 'pleasure', denoted by one's concern for stimulation, ambience and exceeded expectations, and 'physical wellbeing' characterized in terms of bodily support and energy. However, there were no significant differences between the comfort and discomfort ratings on the other six factors. The evidence does not support the proposition that passenger comfort and discomfort are underline by different sets of factors. It is therefore suggested that the evaluation of overall passenger comfort experience, as a whole, employ one spectrum ranging from extreme comfort to discomfort. In study two, a pool of comfort descriptors was collected. Those that were less relevant to passenger comfort were eliminated in a number of steps. Factor analysis was used to classify the remaining descriptors, using respondents' ratings on their potential impact on passenger comfort. Seven factors corresponded to the pre-determined passenger comfort factors from previous research, validating those with an exception of 'proxemics' (concerning one's privacy and control over their situation) but it was argued that this is due to the nature of the factor itself, which is context dependent and generally perceived unconsciously.

  12. Aircraft passenger comfort experience: underlying factors and differentiation from discomfort.

    PubMed

    Ahmadpour, Naseem; Robert, Jean-Marc; Lindgaard, Gitte

    2016-01-01

    Previous studies defined passengers' comfort based on their concerns during the flight and a set of eight experiential factors such as 'peace of mind', 'physical wellbeing', 'pleasure', etc. One Objective of this paper was to determine whether the factors underlying the passengers' experience of comfort differ from those of discomfort. Another objective was to cross-validate those factors. In the first study, respondents provided written reports of flight comfort and discomfort experiences separately and gave ratings on the impact of the eight factors on each experience. Follow up interviews were also conducted. Significant difference was found between comfort and discomfort ratings for two factors of 'pleasure', denoted by one's concern for stimulation, ambience and exceeded expectations, and 'physical wellbeing' characterized in terms of bodily support and energy. However, there were no significant differences between the comfort and discomfort ratings on the other six factors. The evidence does not support the proposition that passenger comfort and discomfort are underline by different sets of factors. It is therefore suggested that the evaluation of overall passenger comfort experience, as a whole, employ one spectrum ranging from extreme comfort to discomfort. In study two, a pool of comfort descriptors was collected. Those that were less relevant to passenger comfort were eliminated in a number of steps. Factor analysis was used to classify the remaining descriptors, using respondents' ratings on their potential impact on passenger comfort. Seven factors corresponded to the pre-determined passenger comfort factors from previous research, validating those with an exception of 'proxemics' (concerning one's privacy and control over their situation) but it was argued that this is due to the nature of the factor itself, which is context dependent and generally perceived unconsciously. PMID:26360222

  13. Evaluation of various sets of acoustic cues for the perception of prevocalic stop consonants. II. Modeling and evaluation.

    PubMed

    Smits, R; ten Bosch, L; Collier, R

    1996-12-01

    The purpose of the study presented in this paper and the accompanying paper [Smits et al., J. Acoust. Soc. Am. 100, 3852-3864 (1996)] is to evaluate whether detailed or gross time-frequency structures are more relevant for the perception of prevocalic stop consonants. To this end, first a perception experiment was carried out with "burst-spliced" stop-vowel utterances. This experiment is described in the accompanying paper. The present paper describes the second part of the investigation, i.e., the simulation of the behavior of the listeners in the perception experiment. First, a number of detailed and gross cues are measured on the stimuli. Next, these cues are mapped onto the observed perceptual data using a formal model of human classification behavior. The results show that in all cases the detailed cues, such as formant transitions, give a better account of the perceptual data than the gross cues, such as the global spectral tilt and its initial change. The best-performing models are interpreted in terms of the acoustic boundaries which are associated with the perceived linguistic contrast. These boundaries are highly interpretable linear functions of five or six acoustic cues, which give a quantitative description of the often-discussed "trade-off" relation between the various cues for perception of place of articulation in stop consonants. PMID:8969487

  14. Comfort model for automobile seat.

    PubMed

    da Silva, Lizandra da; Bortolotti, Silvana Ligia Vincenzi; Campos, Izabel Carolina Martins; Merino, Eugenio Andrés Díaz

    2012-01-01

    Comfort on automobile seats is lived daily by thousands of drivers. Epistemologically, comfort can be understood under the theory of complexity, since it emerges from a chain of interrelationships between man and several elements of the system. This interaction process can engender extreme comfort associated to the feeling of pleasure and wellbeing or, on the other hand, lead to discomfort, normally followed by pain. This article has for purpose the development of a theoretical model that favours the comfort feature on automobile seats through the identification of its facets and indicators. For such, a theoretical study is resorted to, allowing the mapping of elements that constitute the model. The results present a comfort model on automobile seats that contemplates the (physical, psychological, object, context and environment) facets. This model is expected to contribute with the automobile industry for the development of improvements of the ergonomic project of seats to increase the comfort noticed by the users.

  15. Non-Destructive Evaluation Method and Apparatus for Measuring Acoustic Material Nonlinearity

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    An acoustic non-linearity parameter (beta) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members obviates the need for electronic calibration of the measuring equipment. Unlike known substitutional measuring techniques requiring elaborate calibration procedures, the electrical outputs of the capacitive detector of a sample with known beta and the test sample of unknown beta are compared to determine the unknown beta. In order to provide the necessary stability of the present-inventive reference-based approach, the bandpass filters of the measurement system are maintained in a temperature-controlled environment, and the line voltage supplied to said amplifiers is well-regulated.

  16. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival Proportions at John Day Dam, 2009

    SciTech Connect

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Deng, Zhiqun; Fu, Tao; Kim, Jin A.; Johnson, Gary E.; Fischer, Eric S.; Khan, Fenton; Zimmerman, Shon A.; Faber, Derrek M.; Carter, Kathleen M.; Boyd, James W.; Townsend, Richard L.; Skalski, J. R.; Monter, Tyrell J.; Cushing, Aaron W.; Wilberding, Matthew C.; Meyer, Matthew M.

    2011-09-28

    The overall purpose of the acoustic telemetry study at JDA during 2009 was to determine the best configuration and operation for JDA prior to conducting BiOp performance standard tests. The primary objective was to determine the best operation between 30% and 40% spill treatments. Route-specific and JDA to TDA forebay survival estimates, passage distribution, and timing/behavior metrics were used for comparison of 30% to a 40% spill treatments. A secondary objective was to evaluate the performance of TSWs installed in spill bays 15 and 16 and to estimate fish survival rates and passage efficiencies under 30% and 40% spill-discharge treatments each season.

  17. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2010

    SciTech Connect

    Weiland, Mark A.; Woodley, Christa M.; Ploskey, Gene R.; Hughes, James S.; Kim, Jin A.; Deng, Zhiqun; Fu, Tao; Fischer, Eric S.; Skalski, J. R.; Townsend, Richard L.; Duncan, Joanne P.; Hennen, Matthew J.; Wagner, Katie A.; Arntzen, Evan V.; Miller, Benjamin L.; Miracle, Ann L.; Zimmerman, Shon A.; Royer, Ida M.; Khan, Fenton; Cushing, Aaron W.; Etherington, D. J.; Mitchell, T. D.; Elder, T.; Batton, George; Johnson, Gary E.; Carlson, Thomas J.

    2013-05-01

    This report presents survival, behavioral, and fish passage results for yearling and subyearling Chinook salmon smolts and juvenile steelhead tagged with JSATS acoustic micro-transmitters as part of a survival study conducted at John Day Dam during 2010. This study was designed to evaluate the passage and survival of yearling and subyearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a single-release survival estimate model.

  18. Opportunities for energy conservation through thermal comfort control strategies

    SciTech Connect

    Jones, J.; Singh, H.

    1997-06-01

    The primary function of a heating, ventilating and air-conditioning (HVAC) system is either (1) the generation and maintenance of comfort for occupants in a conditioned space; or (2) the supplying of a set of environmental conditions (high humidity, etc.) for a process or product within a space. To achieve these objectives HVAC systems typically consume energy. For building occupants the level of thermal comfort is the result of interactions between factors such as the thermal, visual, and acoustic environments as well as with the indoor air quality. Fanger and others have shown that thermal comfort is correlated with six factors, four environmental and two personal. The environmental factors include: (1) ambient air temperature, (2) humidity, (3) air velocity near the skin surface, and (4) amount of radiant heat exchange between the body and nearby surfaces. The personal factors include the insulation value of the occupants clothing (clo value) and the metabolic rate associated with an activity (met rate). While trying to maintain comfort conditions, typically HVAC systems only attempt to control the room air temperature, ignoring the interactions and influence of the remaining five thermal comfort variables. If a more comprehensive approach is taken to thermal comfort control that simultaneously considers all of the factors then energy consumption can potentially be reduced.

  19. A structure state evaluation method based on electric-thermo-acoustic effect for tension materials

    NASA Astrophysics Data System (ADS)

    Yin, Aijun; Zhang, Panpan; Ouyang, Qi

    2016-10-01

    The material properties of a structure will change over the course of its service life. Monitoring for material properties can be used to evaluate equipment state. Characterising and tracking variations in properties have promising potential for the detection and evaluation of material state caused by fatigue or residual stress. Theoretical analysis for the formation of a thermo-acoustic effect is carried out and it reveals a kind of interaction between the resonance of gas heat and that of solid heat. This paper introduces an electric-thermo-acoustic model with a multi-layered structure and analyses the effects of the material properties on sound pressure. Based on this effect, a method for evaluating the performance of a multi-layered structure material is proposed that can be used to assess a greater number of physical properties than the existing approaches. The simulations and experiments with variations in material property are generated and processed with the proposed model, and the results verify the method’s efficiency.

  20. California School Lighting Design and Evaluation. A Procedure for the Prediction, Specification, and Evaluation of Visual Comfort and Visual Performance in Classrooms.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    This guide is intended to help school administrators, members of school district governing boards, architects, and engineers objectively evaluate school lighting systems. The California school lighting design and evaluation procedure described provides a step-by-step design method that, when used properly, results in balanced lighting for school…

  1. Depth Evaluation of Soft Tissue Mimicking Phantoms Using Surface Acoustic Waves

    NASA Astrophysics Data System (ADS)

    Li, C.; Li, S.; Wei, C.; Wang, R. K.; Huang, Z.

    Surface acoustic wave (SAW) shows advantages in revealing skin mechanical properties. In this paper, we evaluates the elasticity of tissue mimicking phantoms by inversion of SAWs phase velocity to Young's Modulus, the estimated SAWs evaluating depth is determined based on the assumption of that SAWs penetration approximately equals one wavelength. The tissue mimicking phantoms are made of agar with concentration of 1%, 2% and 3%. Their elasticity tested from our system is 13.3 kPa, 53.4 kPa and 257.9 kPa respectively, with expected gradient. The evaluation depth is then estimated as 0.542 mm to 3.403 mm underneath the phantom surface, which indicates that this method is suitable to measure elasticity in dermis layer of skin.

  2. Analysis of bus passenger comfort perception based on passenger load factor and in-vehicle time.

    PubMed

    Shen, Xianghao; Feng, Shumin; Li, Zhenning; Hu, Baoyu

    2016-01-01

    Although bus comfort is a crucial indicator of service quality, existing studies tend to focus on passenger load and ignore in-vehicle time, which can also affect passengers' comfort perception. Therefore, by conducting surveys, this study examines passengers' comfort perception while accounting for both factors. Then, using the survey data, it performs a two-way analysis of variance and shows that both in-vehicle time and passenger load significantly affect passenger comfort. Then, a bus comfort model is proposed to evaluate comfort level, followed by a sensitivity analysis. The method introduced in this study has theoretical implications for bus operators attempting to improve bus service quality.

  3. Honeywell: Comfort and economy

    SciTech Connect

    Lukaszewski, J.

    1995-12-31

    The presentation of the Company starts with having it ranked among the ones operating on the customers` market or those acting on the professional market. But it is not so. Honeywell is beyond such simple criteria. We are a company supplying products, systems and services related with generally conceived automatic control engineering, yet the operational range does comprise so many apparently diversified fields, for instance automatic control in aeronautics, heavy power engineering, building of apartment buildings, detached houses, heat engineering and some others. Nevertheless, our targets are always the same: maximum increase in efficiency and reliability of the process lines controlled by our systems as well as securing the best comfort of work and rest for people who stay in the buildings controlled by our devices. Simultaneously, the utilization of energy sources and the natural environment resources must be as sensible as possible.

  4. Hoof Comfort for Horses

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Aquila Equine Enhancement Products, Inc., of Woburn, Massachusetts, developed magnetic hoof protector pads, called "Power Pads," which support and cushion the impact on a horse's hooves and legs to provide comfort and protection against injuries. The pads were tested by Marshall Space Flight Center's Materials and Processing Laboratory for strength and durability. Putting the pads on a horse does not interfere with its natural movement or flexibility and can be compared to a person changing into athletic shoes for a sporting event. The pads are cut to the appropriate size, and then mounted onto a horse's hooves using conventional shoeing methods. Once attached, the pads protect the hard and soft parts of the hoof by cushioning blows against the hard ground. The design also protects the vulnerable "heel" of the hoof. They are a cost-effective way to protect a horse's hooves since they can be reused.

  5. Spatial ecology of the steephead parrotfish ( Chlorurus microrhinos): an evaluation using acoustic telemetry

    NASA Astrophysics Data System (ADS)

    Welsh, J. Q.; Bellwood, D. R.

    2012-03-01

    Herbivory and other ecosystem processes are widely accepted as important factors in maintaining coral reef resilience. While the spatial scales over which these processes occur have been evaluated, the spatial ecology of individual taxa responsible for shaping these processes is almost entirely unknown. This study combined acoustic telemetry and ecological assessments to evaluate the movement patterns and feeding range of a functionally important coral reef fish, Chlorurus microrhinos (f. Labridae). The diurnal home range and feeding areas of C. microrhinos, on Orpheus Island, Great Barrier Reef, were quantified using active acoustic telemetry. The average diurnal home range of C. microrhinos was 7,830 m2 ± 940 (SE). Core areas of activity (50% kernel utilization distributions) were relatively small, encompassing approximately 22% of an individual's home range (1,690 m2 ± 220). Core areas exhibited greater topographic complexity. C. microrhinos may select these areas because of decreased predation risk. Feeding intensities were not homogenous throughout the home range. Core areas were found to have a greater number of feeding scars and are thus exposed to increased bioerosion and algal removal by C. microrhinos. While important in shaping key ecosystem processes, the ecosystem impact of individual C. microrhinos in Pioneer Bay appears to be restricted to small areas within a narrow band along the reef crest.

  6. A non-invasive acoustic and vibration analysis technique for evaluation of hip joint conditions.

    PubMed

    Glaser, Diana; Komistek, Richard D; Cates, Harold E; Mahfouz, Mohamed R

    2010-02-10

    The performance evaluation of THA outcome is difficult and surgeons often use invasive methods to investigate effectiveness. A non-invasive acoustic and vibration analysis technique has recently been developed for more-in-depth evaluation of in vivo hip conditions. Gait kinematics, corresponding vibration and sound measurement of five THA subjects were analyzed post-operatively using video-fluoroscopy, sound and accelerometer measurements while walking on a treadmill. The sound sensor and a pair of tri-axial accelerometers, externally attached to the pelvic and femoral bone prominences, detected frequencies that are propagated through the femoral head and acetabular cup interactions. A data acquisition system was used to amplify the signal and filter out noise generated by undesired frequencies. In vivo kinematics and femoral head sliding quantified using video fluoroscopy were correlated to the sound and acceleration measurements. Distinct variations between the different subjects were identified. A correlation of sound and acceleration impulses with separation has been achieved. Although, in vivo sounds are quite variable in nature and all correlated well with the visual images. This is the first study to document and correlate visual and audible effects of THA under in-vivo conditions. This study has shown that the development of the acoustic and vibration technique provides a practical method and generates new possibilities for a better understanding of THA performance.

  7. A non-invasive acoustic and vibration analysis technique for evaluation of hip joint conditions.

    PubMed

    Glaser, Diana; Komistek, Richard D; Cates, Harold E; Mahfouz, Mohamed R

    2010-02-10

    The performance evaluation of THA outcome is difficult and surgeons often use invasive methods to investigate effectiveness. A non-invasive acoustic and vibration analysis technique has recently been developed for more-in-depth evaluation of in vivo hip conditions. Gait kinematics, corresponding vibration and sound measurement of five THA subjects were analyzed post-operatively using video-fluoroscopy, sound and accelerometer measurements while walking on a treadmill. The sound sensor and a pair of tri-axial accelerometers, externally attached to the pelvic and femoral bone prominences, detected frequencies that are propagated through the femoral head and acetabular cup interactions. A data acquisition system was used to amplify the signal and filter out noise generated by undesired frequencies. In vivo kinematics and femoral head sliding quantified using video fluoroscopy were correlated to the sound and acceleration measurements. Distinct variations between the different subjects were identified. A correlation of sound and acceleration impulses with separation has been achieved. Although, in vivo sounds are quite variable in nature and all correlated well with the visual images. This is the first study to document and correlate visual and audible effects of THA under in-vivo conditions. This study has shown that the development of the acoustic and vibration technique provides a practical method and generates new possibilities for a better understanding of THA performance. PMID:19931084

  8. Evaluation of the resolution of a metamaterial acoustic leaky wave antenna.

    PubMed

    Naify, Christina J; Rogers, Jeffery S; Guild, Matthew D; Rohde, Charles A; Orris, Gregory J

    2016-06-01

    Acoustic antennas have long been utilized to directionally steer acoustic waves in both air and water. Typically, these antennas are comprised of arrays of active acoustic elements, which are electronically phased to steer the acoustic profile in the desired direction. A new technology, known as an acoustic leaky wave antenna (LWA), has recently been shown to achieve directional steering of acoustic waves using a single active transducer coupled to a transmission line passive aperture. The LWA steers acoustic energy by preferential coupling to an input frequency and can be designed to steer from backfire to endfire, including broadside. This paper provides an analysis of resolution as a function of both input frequency and antenna length. Additionally, the resolution is compared to that achieved using an array of active acoustic elements. PMID:27369149

  9. Evaluation of the inner-surface morphology of an artificial heart by acoustic microscopy.

    PubMed

    Saijo, Y; Okawai, H; Sasaki, H; Yambe, T; Nitta, S; Tanaka, M; Kobayashi, K; Honda, Y

    2000-01-01

    The total artificial heart (TAH) is being developed for permanent replacement of the natural heart instead of heart transplantation. The need for detecting the material fatigue in the TAH is increasing in order to guarantee long-term use. In this study, the inner surface morphology of the TAH was evaluated by a specially developed scanning acoustic microscope (SAM) system operating in the frequency range of 100-200 MHz. The inner sac of our TAH consisted of polyvinylchloride coated with polyurethane, and the SAM investigations were performed before and after the implantations in goats. The amplitude images of the SAM demonstrated protein adhesion on the inner surface of the TAH after the animal experiment, and the phase images showed distortion of the wall with spatial resolution of 0.2 microm. These results suggest the feasibility of a high-frequency ultrasound for evaluating the material fatigue of TAH.

  10. Evaluation of shrinkage and cracking in concrete of ring test by acoustic emission method

    NASA Astrophysics Data System (ADS)

    Watanabe, Takeshi; Hashimoto, Chikanori

    2015-03-01

    Drying shrinkage of concrete is one of the typical problems related to reduce durability and defilation of concrete structures. Lime stone, expansive additive and low-heat Portland cement are used to reduce drying shrinkage in Japan. Drying shrinkage is commonly evaluated by methods of measurement for length change of mortar and concrete. In these methods, there is detected strain due to drying shrinkage of free body, although visible cracking does not occur. In this study, the ring test was employed to detect strain and age cracking of concrete. The acoustic emission (AE) method was adopted to detect micro cracking due to shrinkage. It was recognized that in concrete using lime stone, expansive additive and low-heat Portland cement are effective to decrease drying shrinkage and visible cracking. Micro cracking due to shrinkage of this concrete was detected and evaluated by the AE method.

  11. A framework for the damage evaluation of acoustic emission signals through Hilbert-Huang transform

    NASA Astrophysics Data System (ADS)

    Siracusano, Giulio; Lamonaca, Francesco; Tomasello, Riccardo; Garescì, Francesca; Corte, Aurelio La; Carnì, Domenico Luca; Carpentieri, Mario; Grimaldi, Domenico; Finocchio, Giovanni

    2016-06-01

    The acoustic emission (AE) is a powerful and potential nondestructive testing method for structural monitoring in civil engineering. Here, we show how systematic investigation of crack phenomena based on AE data can be significantly improved by the use of advanced signal processing techniques. Such data are a fundamental source of information that can be used as the basis for evaluating the status of the material, thereby paving the way for a new frontier of innovation made by data-enabled analytics. In this article, we propose a framework based on the Hilbert-Huang Transform for the evaluation of material damages that (i) facilitates the systematic employment of both established and promising analysis criteria, and (ii) provides unsupervised tools to achieve an accurate classification of the fracture type, the discrimination between longitudinal (P-) and traversal (S-) waves related to an AE event. The experimental validation shows promising results for a reliable assessment of the health status through the monitoring of civil infrastructures.

  12. Relief of the occluded ear sensation to improve earmold comfort.

    PubMed

    French-Saint George, M; Barr-Hamilton, R M

    1978-01-01

    Earmold comfort is an important factor in the overall satisfaction a hearing-impaired person has with a hearing aid system. Recent research into the subjective effects of earmold venting indicates that, for the naive hearing-aid user, the solid mold produces a "closed" and "blocked" sensation that is relieved to a degree, depending on the vent diameter. To improve earmold comfort, all earmolds should be vented. However, there are certain types of hearing loss where conventional venting techniques would be undesirable, in particular, cases of severe to profound hearing loss where venting would not only adversely affect the desired frequency response characteristics of the hearing aid but would also lead to serious acoustic feedback problems. For this reason a simple system has been developed with sintered filters in the vent line, thus allowing all earmolds to be vented to relieve the occluded ear sensation although retaining the acoustic characteristics of the closed earmold.

  13. Evaluation of thermal comfort, physiological, hematological, and seminal features of buffalo bulls in an artificial insemination station in a tropical environment.

    PubMed

    Barros, Daniel Vale; Silva, Lilian Kátia Ximenes; de Brito Lourenço, José; da Silva, Aluizio Otávio Almeida; E Silva, André Guimarães Maciel; Franco, Irving Montanar; Oliveira, Carlos Magno Chaves; Tholon, Patrícia; Martorano, Lucieta Guerreiro; Garcia, Alexandre Rossetto

    2015-06-01

    This study aimed to assess the variation over time in thermal comfort indices and the behavior of physiological parameters related to thermolysis, blood parameters, and semen in natura of buffalo bulls reared in tropical climate. The study was carried out in an artificial insemination station under a humid tropical climate (Afi according to Köppen). Ten water buffalo bulls (Bubalus bubalis) were used during the 5 months (April to August) of study. The environmental Temperature Humidity Index (THId) and the pen microclimate Temperature Humidity Index (THIp) were calculated. Every 25 days, respiratory rate (RR), heart rate (HR), rectal temperature (RT), and Benezra's thermal comfort index (BTCI) were assessed in the morning and in the afternoon. A blood assay was performed every month, while semen was collected weekly. THIp did not vary over the months (P > 0.05) and was higher in the afternoon than in the morning (77.7 ± 2.6 versus 81.8 ± 2.1, P < 0.05). RR, HR, and BTCI significantly increased over the months and were different between the periods of the day (P > 0.05) but within the physiological limits. RT varied between the periods of the day and decreased over the months, being the lowest in August (37.8 ± 0.7 °C), time-impacted hematocrit, mean corpuscular volume, hemoglobin levels, and spermatic gross motility and vigor (P < 0.05). Thus, buffalo bulls reared under a humid tropical climate may have variations in thermal comfort during the hotter periods but are able to efficiently activate thermoregulatory mechanisms and maintain homeothermy, hence preserving their physiological and seminal parameters at normal levels.

  14. A High Performance Pocket-Size System for Evaluations in Acoustic Signal Processing

    NASA Astrophysics Data System (ADS)

    Rass, Uwe; Steeger, Gerhard H.

    2001-12-01

    Custom-made hardware is attractive for sophisticated signal processing in wearable electroacoustic devices, but has a high initial cost overhead. Thus, signal processing algorithms should be tested thoroughly in real application environments by potential end users prior to the hardware implementation. In addition, the algorithms should be easily alterable during this test phase. A wearable system which meets these requirements has been developed and built. The system is based on the high performance signal processor Motorola DSP56309. This device also includes high quality stereo analog-to-digital-(ADC)- and digital-to-analog-(DAC)-converters with 20 bit word length each. The available dynamic range exceeds 88 dB. The input and output gains can be adjusted by digitally controlled potentiometers. The housing of the unit is small enough to carry it in a pocket (dimensions 150 × 80 × 25 mm). Software tools have been developed to ease the development of new algorithms. A set of configurable Assembler code modules implements all hardware dependent software routines and gives easy access to the peripherals and interfaces. A comfortable fitting interface allows easy control of the signal processing unit from a PC, even by assistant personnel. The device has proven to be a helpful means for development and field evaluations of advanced new hearing aid algorithms, within interdisciplinary research projects. Now it is offered to the scientific community.

  15. Development and Evaluation of New Coupling System for Lower Limb Prostheses with Acoustic Alarm System

    PubMed Central

    Eshraghi, Arezoo; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ahmadian, Jalil; Rahmati, Bizhan; Abas, Wan Abu Bakar Wan

    2013-01-01

    Individuals with lower limb amputation need a secure suspension system for their prosthetic devices. A new coupling system was developed that is capable of suspending the prosthesis. The system's safety is ensured through an acoustic alarm system. This article explains how the system works and provides an in vivo evaluation of the device with regard to pistoning during walking. The system was designed to be used with silicone liners and is based on the requirements of prosthetic suspension systems. Mechanical testing was performed using a universal testing machine. The pistoning during walking was measured using a motion analysis system. The new coupling device produced significantly less pistoning compared to a common suspension system (pin/lock). The safety alarm system would buzz if the suspension was going to fail. The new coupling system could securely suspend the prostheses in transtibial amputees and produced less vertical movement than the pin/lock system. PMID:23881340

  16. Thermal comfort in tropical classrooms

    SciTech Connect

    Kwok, A.G.

    1998-10-01

    This paper examines the comfort criteria of ANSI/ASHRAE Standard 55-1992 for their applicability in tropical classrooms. A field study conducted in Hawaii used a variety of methods to collect the data: survey questionnaires, physical measurements, interviews, and behavioral observations. A total of 3,544 students and teachers completed questionnaires in 29 naturally ventilated and air-conditioned classrooms in six schools during two seasons. The majority of classrooms failed to meet the physical specifications of the Standard 55 comfort zone. Thermal neutrality, preference, and acceptability results are compared with other field studies and the Standard 55 criteria. Acceptability votes by occupants of both naturally ventilated and air-conditioned classrooms exceeded the standard`s 80% acceptability criteria, regardless of whether physical conditions were in or out of the comfort zone. Responses from these two school populations suggest not only a basis for separate comfort standards but energy conservation opportunities through raising thermostat set points.

  17. Comfort over Pain in Pregnancy.

    PubMed

    Charles, Niamh A; Yount, Susan; Morgan, Anne

    2016-06-01

    Pregnancy is often a time when chronic pain is exacerbated, or when acute pain appears. Frequently the easiest intervention within reach, for both chronic and acute pain, is a prescription. However, medication cannot correct the cause of the pain; instead it alters the person's experiential perception of the pain. In addition, medication exposes both mother and fetus to risks. To provide simple, evidence-based, holistic/alternative remedies for women who experienced nonemergent pain during pregnancy. Holistic/alternative techniques for increasing comfort were taught to the participants and individualized during three sessions. Levels of pain and comfort were measured before and after the treatment, using the validated General Comfort Questionnaire and Pain Outcomes Profile. Pain scores decreased from an average of 5.8/10 to 3.5/10 (p = .00). Comfort scores increased from an average of 17.5 to 30 (p = .00). PMID:27105573

  18. Comparative evaluation of Space Transportation System (STS)-3 flight and acoustic test random vibration response of the OSS-1 payload

    NASA Technical Reports Server (NTRS)

    On, F. J.

    1983-01-01

    A comparative evaluation of the Space Transportation System (STS)-3 flight and acoustic test random vibration response of the Office of Space Science-1 (OSS-1) payload is presented. The results provide insight into the characteristics of vibroacoustic response of pallet payload components in the payload bay during STS flights.

  19. Evaluation of photo-acoustic infrared multigas analyzer in measuring concentrations of greenhouse gases emitted from feedlot soil/manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Photo-acoustic infrared multigas analyzers (PIMAs) are being increasingly utilized to measure concentrations and fluxes of greenhouse gases (i.e., N2O, CO2, and CH4) at the soil surface because of their low cost, portability, and ease of operation. This research evaluated a PIMA in combination with ...

  20. Acoustical tree evaluation of Coptotermes Formosanus (Isoptera: Rhinotermitidae) with imidacloprid and noviflumeron in historic Jackson Square, New Orleans, Louisiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nine years of periodic acoustical monitoring of 93 trees active with Formosan subterranean termite, Coptotermes formosanus Shiraki, evaluated imidacloprid tree foam and noviflumuron bait on activity in trees. Long term, imidacloprid suppressed but did not eliminate termite activity in treated trees...

  1. Non-destructive electromagnetic-acoustic evaluation methods of anisotropy and elastic properties in structural alloy steel rolled products

    NASA Astrophysics Data System (ADS)

    Muraviev, V. V.; Muravieva, O. V.; Gabbasova, M. A.

    2015-10-01

    Application opportunities of acoustic structural analysis methods for evaluation of elastic properties and anisotropy by the example of cold-rolled sheets and spring steel rods are presented. Methods are based on application of non-contact electromagnetic-acoustic transducers of encircling and laid-on types developed by the authors and measurements of volume, Rayleigh and Lamb waves parameters. The methods developed can be used as a research tool of material structural analysis, anisotropy of properties when choosing heat treatment techniques and conditions, under intensive plastic deformation and other external energy deposition, including non-conventional material production with hierarchy structure and development of new technologies and safe constructions.

  2. Exploratory tests of a simple aero-mechanical ride comfort system for lightly loaded aircraft. [evaluation of gust alleviating aircraft control surfaces

    NASA Technical Reports Server (NTRS)

    Hewes, D. E.; Stewart, E. C.

    1974-01-01

    Some exploratory wind tunnel and radio-controlled free-flight tests were made with a small high-wing airplane model (1.23m wing span) to study the concept of a simple aero mechanical system intended to alleviate gust loads and improve ride comfort of lightly loaded aircraft. The system consisted essentially of the outer portions of each wing being hinged in the chordwise direction and connected directly to the wing flaps using internal counter weights to provide neutral mass balance. When the wing experienced a change in velocity or angle of attack, the movable wing panels, acting as sensors and flap actuators, deflected in response to the changes in lift on the wing. The corresponding movements of the interconnected flaps tended to reduce the changes in the wing lift.

  3. Averting comfortable lifestyle crises.

    PubMed

    Bilton, Rod

    2013-01-01

    : alternative non-sugar sweeteners; toxic side-effects of aspartame. Stevia and xylitol as healthy sugar replacements; the role of food processing in dietary health; and beneficial effects of resistant starch in natural and processed foods. The rise of maize and soya-based vegetable oils have led to omega-6 fat overload and imbalance in the dietary ratio of omega-3 to omega-6 fats. This has led to toxicity studies with industrial trans fats; investigations on health risks associated with stress and comfort eating; and abdominal obesity. Other factors to consider are: diet, cholesterol and oxidative stress, as well as the new approaches to the chronology of eating and the health benefits of intermittent fasting.

  4. Averting comfortable lifestyle crises.

    PubMed

    Bilton, Rod

    2013-01-01

    : alternative non-sugar sweeteners; toxic side-effects of aspartame. Stevia and xylitol as healthy sugar replacements; the role of food processing in dietary health; and beneficial effects of resistant starch in natural and processed foods. The rise of maize and soya-based vegetable oils have led to omega-6 fat overload and imbalance in the dietary ratio of omega-3 to omega-6 fats. This has led to toxicity studies with industrial trans fats; investigations on health risks associated with stress and comfort eating; and abdominal obesity. Other factors to consider are: diet, cholesterol and oxidative stress, as well as the new approaches to the chronology of eating and the health benefits of intermittent fasting. PMID:24547668

  5. A New Method to Evaluate Surface Defects with an Electromagnetic Acoustic Transducer.

    PubMed

    Zhang, Kang; Yi, Pengxing; Li, Yahui; Hui, Bing; Zhang, Xuming

    2015-01-01

    Characterizing a surface defect is very crucial in non-destructive testing (NDT). We employ an electromagnetic acoustic transducer (EMAT) to detect the surface defect of a nonmagnetic material. An appropriate feature that can avoid the interference of the human factor is vital for evaluating the crack quantitatively. Moreover, it can also reduce the influence of other factors, such as the lift-off, during the testing. In this paper, we conduct experiments at various depths of surface cracks in an aluminum plate, and a new feature, lift-off slope (LOS), is put forward for the theoretical and experimental analyses of the lift-off effect on the receiving signals. Besides, by changing the lift-off between the receiving probe and the sample for testing, a new method is adopted to evaluate surface defects with the EMAT. Compared with other features, the theoretical and experimental results show that the feature lift-off slope has many advantages prior to the other features for evaluating the surface defect with the EMAT. This can reduce the lift-off effect of one probe. Meanwhile, it is not essential to measure the signal without defects. PMID:26193282

  6. Resource Evaluation and Energy Production Estimate for a Tidal Energy Conversion Installation using Acoustic Flow Measurements

    NASA Astrophysics Data System (ADS)

    Gagnon, Ian; Baldwin, Ken; Wosnik, Martin

    2015-11-01

    The ``Living Bridge'' project plans to install a tidal turbine at Memorial Bridge in the Piscataqua River at Portsmouth, NH. A spatio-temporal tidal energy resource assessment was performed using long term bottom-deployed Acoustic Doppler Current Profilers ADCP. Two locations were evaluated: at the planned deployment location and mid-channel. The goal was to determine the amount of available kinetic energy that can be converted into usable electrical energy on the bridge. Changes in available kinetic energy with ebb/flood and spring/neap tidal cycles and electrical energy demand were analyzed. A system model is used to calculate the net energy savings using various tidal generator and battery bank configurations. Differences in the tidal characteristics between the two measurement locations are highlighted. Different resource evaluation methodologies were also analyzed, e.g., using a representative ADCP ``bin'' vs. a more refined, turbine-geometry-specific methodology, and using static bin height vs. bin height that move w.r.t. the free surface throughout a tidal cycle (representative of a bottom-fixed or floating turbine deployment, respectively). ADCP operating frequencies and bin sizes affect the standard deviation of measurements, and measurement uncertainties are evaluated. Supported by NSF-IIP grant 1430260.

  7. A New Method to Evaluate Surface Defects with an Electromagnetic Acoustic Transducer

    PubMed Central

    Zhang, Kang; Yi, Pengxing; Li, Yahui; Hui, Bing; Zhang, Xuming

    2015-01-01

    Characterizing a surface defect is very crucial in non-destructive testing (NDT). We employ an electromagnetic acoustic transducer (EMAT) to detect the surface defect of a nonmagnetic material. An appropriate feature that can avoid the interference of the human factor is vital for evaluating the crack quantitatively. Moreover, it can also reduce the influence of other factors, such as the lift-off, during the testing. In this paper, we conduct experiments at various depths of surface cracks in an aluminum plate, and a new feature, lift-off slope (LOS), is put forward for the theoretical and experimental analyses of the lift-off effect on the receiving signals. Besides, by changing the lift-off between the receiving probe and the sample for testing, a new method is adopted to evaluate surface defects with the EMAT. Compared with other features, the theoretical and experimental results show that the feature lift-off slope has many advantages prior to the other features for evaluating the surface defect with the EMAT. This can reduce the lift-off effect of one probe. Meanwhile, it is not essential to measure the signal without defects. PMID:26193282

  8. Field evaluation of shallow-water acoustic doppler current profiler discharge measurements

    USGS Publications Warehouse

    Rehmel, M.S.

    2007-01-01

    In 2004, the U.S. Geological Survey (USGS) Office of Surface Water staff and USGS Water Science employees began testing the StreamPro, an acoustic Doppler current profiler (ADCP) for shallow-water discharge measurements. Teledyne RD Instruments introduced the StreamPro in December of 2003. The StreamPro is designed to make a "moving boat" discharge measurement in streams with depths between 0.15 and 2 m. If the StreamPro works reliably in these conditions, it will allow for use of ADCPs in a greater number of streams than previously possible. Evaluation sites were chosen to test the StreamPro over a range of conditions. Simultaneous discharge measurements with mechanical and other acoustic meters, along with stable rating curves at established USGS streamflow-gaging stations, were used for comparisons. The StreamPro measurements ranged in mean velocity from 0.076 to 1.04 m/s and in discharge from 0.083 m 3/s to 43.4 m 3/s. Tests indicate that discharges measured with the StreamPro compare favorably to the discharges measured with the other meters when the mean channel velocity is greater than 0.25 m/s. When the mean channel velocity is less than 0.25 m/s, the StreamPro discharge measurements for individual transects have greater variability than those StreamPro measurements where the mean channel velocity is greater than 0.25 m/s. Despite this greater variation in individual transects, there is no indication that the StreamPro measured discharges (the mean discharge for all transects) are biased, provided that enough transects are used to determine the mean discharge. ?? 2007 ASCE.

  9. Evaluating damage potential of cryogenic concrete using acoustic emission sensors and permeability testing

    NASA Astrophysics Data System (ADS)

    Kogbara, Reginald B.; Parsaei, Boback; Iyengar, Srinath R.; Grasley, Zachary C.; Masad, Eyad A.; Zollinger, Dan G.

    2014-04-01

    This study evaluates the damage potential of concrete of different mix designs subjected to cryogenic temperatures, using acoustic emission (AE) and permeability testing. The aim is to investigate design methodologies that might be employed to produce concrete that resists damage when cooled to cryogenic temperatures. Such concrete would be suitable for primary containment of liquefied natural gas (LNG) and could replace currently used 9% Ni steel, thereby leading to huge cost savings. In the experiments described, concrete cubes, 150 mm x 150 mm x 150 mm, were cast using four different mix designs. The four mixes employed siliceous river sand as fine aggregate. Moreover, limestone, sandstone, trap rock and lightweight aggregate were individually used as coarse aggregates in the mixes. The concrete samples were then cooled from room temperature (20°C) to cryogenic temperature (-165°C) in a temperature chamber. AE sensors were placed on the concrete cubes during the cryogenic freezing process. The damage potential was evaluated in terms of the growth of damage as determined from AE, as a function of temperature and concrete mixture design. The damage potential observed was validated with water permeability testing. Initial results demonstrate the effects of the coefficient of thermal expansion (CTE) of the aggregates on damage growth. Concrete damage (cracking) resistance generally decreased with increasing coarse aggregate CTE, and was in the order, limestone ≥ trap rock << lightweight aggregate ≥ sandstone. Work is in progress to fully understand thermal dilation and damage growth in concrete due to differential CTE of its components.

  10. Identifying factors of bicycle comfort: An online survey with enthusiast cyclists.

    PubMed

    Ayachi, F S; Dorey, J; Guastavino, C

    2015-01-01

    Racing bicycles have evolved significantly over the past decades as technology and cyclists' comfort have become a critical design issue. Although ample research has been conducted on comfort for other means of transportation, cyclists' perception of dynamic comfort has received scant attention in the scientific literature. The present study investigates how enthusiast cyclists conceptualize comfort using an online survey with 244 respondents. The purpose is to determine which factors contribute to comfort when riding a bicycle, to identify situations in which comfort is relevant and to determine the extent to which vibrations play a role in comfort evaluations. We found that comfort is influenced by factors related to bicycle components (specifically the frame, saddle and handlebar), as well as environmental factors (type or road, weather conditions) and factors related to the cyclist (position, adjustments, body parts). Respondents indicated that comfort is a concern when riding a bicycle in most situations and they believed that comfort is compatible with performance. The PCA analysis shows that for the perception "human factor-body parts" are put in evidence, and the "cyclist's comfort" evaluation is mainly based on certain qualities related to the bicycle components, then the road and external conditions (e.g. weather, temperature).

  11. Comfortable loudness level: stimulus effects, long-term reliability, and predictability.

    PubMed

    Cox, R M

    1989-12-01

    This paper reports the results of a series of investigations of comfortable loudness levels with particular reference to their application to hearing aid gain prescriptions. Experiment 1 studied the effects of several stimulus waveforms, bandwidths, and durations on comfortable loudness levels for normal and hearing impaired listeners. Speech band comfort levels were found to be significantly higher than equal-duration noise band or warble tone comfort levels. Comfortable loudness levels were found to be independent of warble tone modulation parameters and of stimulus bandwidth (stimuli did not exceed critical bandwidths). In Experiment 2, reliability of comfortable loudness levels was evaluated in hearing-impaired subjects over two consecutive 1-year periods. Results indicated that comfortable loudness levels were slightly less reliable than thresholds. In addition, the results were consistent with a hypothesis that exposure to amplified sound produces a small increase in comfortable loudness levels. In Experiment 3, data from 67 hearing-impaired subjects were used to develop regression equations for prediction of comfortable loudness levels. Thresholds at the test frequencies were combined with comfortable loudness data at 500 Hz and 4,000 Hz. The prediction method was then evaluated using a new group of 25 subjects. Accuracy of predictions of comfort levels was substantially better with the new method than with an older method that relied exclusively on threshold data. Relevance of the outcomes to hearing aid fitting procedures is discussed.

  12. Operating Comfort Prediction Model of Human-Machine Interface Layout for Cabin Based on GEP.

    PubMed

    Deng, Li; Wang, Guohua; Chen, Bo

    2015-01-01

    In view of the evaluation and decision-making problem of human-machine interface layout design for cabin, the operating comfort prediction model is proposed based on GEP (Gene Expression Programming), using operating comfort to evaluate layout scheme. Through joint angles to describe operating posture of upper limb, the joint angles are taken as independent variables to establish the comfort model of operating posture. Factor analysis is adopted to decrease the variable dimension; the model's input variables are reduced from 16 joint angles to 4 comfort impact factors, and the output variable is operating comfort score. The Chinese virtual human body model is built by CATIA software, which will be used to simulate and evaluate the operators' operating comfort. With 22 groups of evaluation data as training sample and validation sample, GEP algorithm is used to obtain the best fitting function between the joint angles and the operating comfort; then, operating comfort can be predicted quantitatively. The operating comfort prediction result of human-machine interface layout of driller control room shows that operating comfort prediction model based on GEP is fast and efficient, it has good prediction effect, and it can improve the design efficiency.

  13. Operating Comfort Prediction Model of Human-Machine Interface Layout for Cabin Based on GEP

    PubMed Central

    Deng, Li; Wang, Guohua; Chen, Bo

    2015-01-01

    In view of the evaluation and decision-making problem of human-machine interface layout design for cabin, the operating comfort prediction model is proposed based on GEP (Gene Expression Programming), using operating comfort to evaluate layout scheme. Through joint angles to describe operating posture of upper limb, the joint angles are taken as independent variables to establish the comfort model of operating posture. Factor analysis is adopted to decrease the variable dimension; the model's input variables are reduced from 16 joint angles to 4 comfort impact factors, and the output variable is operating comfort score. The Chinese virtual human body model is built by CATIA software, which will be used to simulate and evaluate the operators' operating comfort. With 22 groups of evaluation data as training sample and validation sample, GEP algorithm is used to obtain the best fitting function between the joint angles and the operating comfort; then, operating comfort can be predicted quantitatively. The operating comfort prediction result of human-machine interface layout of driller control room shows that operating comfort prediction model based on GEP is fast and efficient, it has good prediction effect, and it can improve the design efficiency. PMID:26448740

  14. Perceptual and acoustic evaluation of individuals with laryngopharyngeal reflux pre- and post-treatment.

    PubMed

    Selby, Julia C; Gilbert, Harvey R; Lerman, J W

    2003-12-01

    Thirteen individuals with laryngopharyngeal reflux (LPR) were studied pre- and post-treatment. The effect of treatment on perceptual ratings of voice quality and frequency and intensity measures was examined. Relationships between perceptual and acoustic parameters were assessed descriptively. Results showed a small, but significant improvement in the perception of voice quality post-treatment. No significant differences were found between pre- and post-treatment means for any of the acoustic measures except harmonics-to-noise ratio (HNR). Descriptive analyses showed some association between perceptual ratings and acoustic measures. Discussion of results focuses on severity of LPR.

  15. Using Distributed Acoustic Sensing (DAS) for Multichannel Analysis of Surface Waves (MASW) to Evaluate Ground Stiffness

    NASA Astrophysics Data System (ADS)

    Baldwin, J. A.; Fratta, D.; Wang, H. F.; Lord, N. E.; Chalari, A.; Karaulanov, R.; Nigbor, R. L.; Lancelle, C.; Castongia, E.

    2014-12-01

    Since its introduction by Park, et al. (1999), Multichannel Analysis of Surface Waves (MASW) has become an invaluable geophysical technique for geotechnical site investigation. The technique is primarily focused on developing 2-D and 3-D shear stiffness vs. depth images of the near surface. MASW involves measuring surfaces waves of various frequencies produced by a seismic source, such as a sledgehammer or vibroseis source, which is evaluated to determine the velocity of the shear waves propagating through the subsurface at shallow depths. Traditionally, this technique relies on a long string of geophones as receivers. However, our study utilized a Distributed Acoustic Sensor array to detect ground motion caused by passing surface waves at a spatial resolution of one meter. The purpose of this investigation is to compare the effectiveness of using a DAS array for MASW data collection instead of traditional geophones. Data were collected at the Network for Earthquake Engineering Simulation's Garner Valley Downhole Array site (NEES's GVDA). Various time-frequency filtering and moving window cross correlation (MWCC) techniques were examined for extracting the surface wave dispersion. The results were found to be in good agreement with those previously obtained by Stokoe et al. (2004).

  16. Evaluation of marginal failures of dental composite restorations by acoustic emission analysis.

    PubMed

    Gu, Ja-Uk; Choi, Nak-Sam

    2013-01-01

    In this study, a nondestructive method based on acoustic emission (AE) analysis was developed to evaluate the marginal failure states of dental composite restorations. Three types of ring-shaped substrates, which were modeled after a Class I cavity, were prepared from polymethyl methacrylate, stainless steel, and human molar teeth. A bonding agent and a composite resin were applied to the ring-shaped substrates and cured by light exposure. At each time-interval measurement, the tooth substrate presented a higher number of AE hits than polymethyl methacrylate and steel substrates. Marginal disintegration estimations derived from cumulative AE hits and cumulative AE energy parameters showed that a signification portion of marginal gap formation was already realized within 1 min at the initial light-curing stage. Estimation based on cumulative AE energy gave a higher level of marginal failure than that based on AE hits. It was concluded that the AE analysis method developed in this study was a viable approach in predicting the clinical survival of dental composite restorations efficiently within a short test period.

  17. Non-destructive evaluation of laboratory scale hydraulic fracturing using acoustic emission

    NASA Astrophysics Data System (ADS)

    Hampton, Jesse Clay

    The primary objective of this research is to develop techniques to characterize hydraulic fractures and fracturing processes using acoustic emission monitoring based on laboratory scale hydraulic fracturing experiments. Individual microcrack AE source characterization is performed to understand the failure mechanisms associated with small failures along pre-existing discontinuities and grain boundaries. Individual microcrack analysis methods include moment tensor inversion techniques to elucidate the mode of failure, crack slip and crack normal direction vectors, and relative volumetric deformation of an individual microcrack. Differentiation between individual microcrack analysis and AE cloud based techniques is studied in efforts to refine discrete fracture network (DFN) creation and regional damage quantification of densely fractured media. Regional damage estimations from combinations of individual microcrack analyses and AE cloud density plotting are used to investigate the usefulness of weighting cloud based AE analysis techniques with microcrack source data. Two granite types were used in several sample configurations including multi-block systems. Laboratory hydraulic fracturing was performed with sample sizes ranging from 15 x 15 x 25 cm3 to 30 x 30 x 25 cm 3 in both unconfined and true-triaxially confined stress states using different types of materials. Hydraulic fracture testing in rock block systems containing a large natural fracture was investigated in terms of AE response throughout fracture interactions. Investigations of differing scale analyses showed the usefulness of individual microcrack characterization as well as DFN and cloud based techniques. Individual microcrack characterization weighting cloud based techniques correlated well with post-test damage evaluations.

  18. Air-coupled acoustic method for testing and evaluation of microscale structures.

    PubMed

    Ricci, Justin; Cetinkaya, Cetin

    2007-05-01

    A noncontact testing and characterization approach for microscale structures based on air-coupled acoustic excitation and optical sensing is proposed and demonstrated. Using an air-coupled transducer to externally excite and a laser Doppler vibrometer/interferometer to capture transient displacement wave forms, the experimental approach results in a technique to determine mechanical properties of microscale structural elements. The effectiveness of this method has been demonstrated on commercially available microcantilever beams and microscale rotational oscillators fabricated for this study. The resonance frequencies and mechanical properties (Young's modulus and stiffness) extracted from the transient displacement wave forms have been compared, with good agreement, to computational and simplified analytical models for each case. It is also shown that the technique could serve to diagnose stiction problems of microscale structures. Some potential advantages of the approach described include the simplicity of the test setup, functionality at room conditions, noncontact and nondestructive operations, and repeatability and rapid turn-around time for the evaluation of modal parameters and mechanical properties of microscale structures.

  19. Acoustic Imaging of Microstructure and Evaluation of the Adhesive's Physical, Mechanical and Chemical Properties Changes at Different Cure States

    NASA Astrophysics Data System (ADS)

    Severina, I. A.; Fabre, A. J.; Maeva, E. Yu.

    Epoxy thermoset adhesives transform during cure from liquid state into the highly cross-linked solid. Cure state of the material depends on condition of the reaction (temperature, pressure, time etc.) and resin/hardener ratio. It is known that the cure degree of the adhesive correlates with adhesion strength, which is critical for structural adhesives used in automotive, aerospace and marine industries. In this work, characterization of cure process of the adhesive with acoustic methods is presented. Evolution of the acoustic and elastic properties (attenuation, sound velocity, density, elastic moduli) during cure reaction was monitored in relation to the substantial physical and chemical changes of the material. These macro parameters of the adhesive were compared with the material's microstructure obtained by high-resolution acoustic microscopy technique in frequencies range of 50-400 MHz. Development of the microstructure of the adhesive as it cures at different conditions has been investigated. Appearance and development of the granular structure on the adhesive interface during cure reaction has been demonstrated. Acoustic images were analyzed by mathematical method to quantitatively characterize distribution of the adhesive's components. Statistical analysis of such images provides an accurate quantitative measure of the degree of cure of such samples. Research results presented in this paper can be useful as a basis for non-destructive evaluation of the adhesive materials

  20. Speech privacy and annoyance considerations in the acoustic environment of passenger cars of high-speed trains.

    PubMed

    Jeon, Jin Yong; Hong, Joo Young; Jang, Hyung Suk; Kim, Jae Hyeon

    2015-12-01

    It is necessary to consider not only annoyance of interior noises but also speech privacy to achieve acoustic comfort in a passenger car of a high-speed train because speech from other passengers can be annoying. This study aimed to explore an optimal acoustic environment to satisfy speech privacy and reduce annoyance in a passenger car. Two experiments were conducted using speech sources and compartment noise of a high speed train with varying speech-to-noise ratios (SNRA) and background noise levels (BNL). Speech intelligibility was tested in experiment I, and in experiment II, perceived speech privacy, annoyance, and acoustic comfort of combined sounds with speech and background noise were assessed. The results show that speech privacy and annoyance were significantly influenced by the SNRA. In particular, the acoustic comfort was evaluated as acceptable when the SNRA was less than -6 dB for both speech privacy and noise annoyance. In addition, annoyance increased significantly as the BNL exceeded 63 dBA, whereas the effect of the background-noise level on the speech privacy was not significant. These findings suggest that an optimal level of interior noise in a passenger car might exist between 59 and 63 dBA, taking normal speech levels into account.

  1. Making noise comfortable for people

    SciTech Connect

    Leventhall, H.G.; Wise, S.S.

    1998-10-01

    Typical HVAC noise may produce an uncomfortable environment, leading to the associated problems of general dissatisfaction and reduced productivity. It is not sufficient to have good thermal, lighting, and air cleanliness conditions if the noise is disturbing. In this paper, noise comfort is considered, with special emphasis on the developing criteria for low-frequency noise.

  2. Comfort Zone: Model or Metaphor

    ERIC Educational Resources Information Center

    Brown, Mike

    2008-01-01

    The comfort zone model is widespread within adventure education literature. It is based on the belief that when placed in a stressful situation people will respond by overcoming their fear and therefore grow as individuals. This model is often presented to participants prior to activities with a highly perceived sense of risk and challenge which…

  3. A review of ride comfort studies in the United Kingdom

    NASA Technical Reports Server (NTRS)

    Griffin, M. J.

    1975-01-01

    United Kingdom research which is relevant to the assessment of vehicle ride comfort was reviewed. The findings reported in approximately 80 research papers are outlined, and an index to the areas of application of these studies is provided. The data obtained by different research groups are compared, and it is concluded that, while there are some areas of general agreement, the findings obtained from previous United Kingdom research are insufficient to define a general purpose ride comfort evaluation procedure. The degree to which United Kingdom research supports the vibration evaluation procedure defined in the current International Standard on the evaluation of human exposure to whole-body vibration is discussed.

  4. Evaluation of SHM System Produced by Additive Manufacturing via Acoustic Emission and Other NDT Methods

    PubMed Central

    Strantza, Maria; Aggelis, Dimitrios G.; de Baere, Dieter; Guillaume, Patrick; van Hemelrijck, Danny

    2015-01-01

    During the last decades, structural health monitoring (SHM) systems are used in order to detect damage in structures. We have developed a novel structural health monitoring approach, the so-called “effective structural health monitoring” (eSHM) system. The current SHM system is incorporated into a metallic structure by means of additive manufacturing (AM) and has the possibility to advance life safety and reduce direct operative costs. It operates based on a network of capillaries that are integrated into an AM structure. The internal pressure of the capillaries is continuously monitored by a pressure sensor. When a crack nucleates and reaches the capillary, the internal pressure changes signifying the existence of the flaw. The main objective of this paper is to evaluate the crack detection capacity of the eSHM system and crack location accuracy by means of various non-destructive testing (NDT) techniques. During this study, detailed acoustic emission (AE) analysis was applied in AM materials for the first time in order to investigate if phenomena like the Kaiser effect and waveform parameters used in conventional metals can offer valuable insight into the damage accumulation of the AM structure as well. Liquid penetrant inspection, eddy current and radiography were also used in order to confirm the fatigue damage and indicate the damage location on un-notched four-point bending AM metallic specimens with an integrated eSHM system. It is shown that the eSHM system in combination with NDT can provide correct information on the damage condition of additive manufactured metals. PMID:26506349

  5. Evaluation of SHM system produced by additive manufacturing via acoustic emission and other NDT methods.

    PubMed

    Strantza, Maria; Aggelis, Dimitrios G; de Baere, Dieter; Guillaume, Patrick; van Hemelrijck, Danny

    2015-01-01

    During the last decades, structural health monitoring (SHM) systems are used in order to detect damage in structures. We have developed a novel structural health monitoring approach, the so-called "effective structural health monitoring" (eSHM) system. The current SHM system is incorporated into a metallic structure by means of additive manufacturing (AM) and has the possibility to advance life safety and reduce direct operative costs. It operates based on a network of capillaries that are integrated into an AM structure. The internal pressure of the capillaries is continuously monitored by a pressure sensor. When a crack nucleates and reaches the capillary, the internal pressure changes signifying the existence of the flaw. The main objective of this paper is to evaluate the crack detection capacity of the eSHM system and crack location accuracy by means of various non-destructive testing (NDT) techniques. During this study, detailed acoustic emission (AE) analysis was applied in AM materials for the first time in order to investigate if phenomena like the Kaiser effect and waveform parameters used in conventional metals can offer valuable insight into the damage accumulation of the AM structure as well. Liquid penetrant inspection, eddy current and radiography were also used in order to confirm the fatigue damage and indicate the damage location on un-notched four-point bending AM metallic specimens with an integrated eSHM system. It is shown that the eSHM system in combination with NDT can provide correct information on the damage condition of additive manufactured metals.

  6. Evaluating the Effectiveness of an Ultrasonic Acoustic Deterrent for Reducing Bat Fatalities at Wind Turbines

    PubMed Central

    Arnett, Edward B.; Hein, Cris D.; Schirmacher, Michael R.; Huso, Manuela M. P.; Szewczak, Joseph M.

    2013-01-01

    Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21–51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for

  7. Evaluating the Effectiveness of an Ultrasonic Acoustic Deterrent for Reducing Bat Fatalities at Wind Turbines.

    PubMed

    Arnett, Edward B; Hein, Cris D; Schirmacher, Michael R; Huso, Manuela M P; Szewczak, Joseph M

    2013-01-01

    Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21-51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for

  8. Evaluating the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at wind turbines

    USGS Publications Warehouse

    Arnett, Edward B.; Hein, Cris D.; Schirmacher, Michael R.; Huso, Manuela M.P.; Szewczak, Joseph M.

    2013-01-01

    Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21–51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for

  9. Evaluation of real-time acoustical holography for breast imaging and biopsy guidance

    NASA Astrophysics Data System (ADS)

    Lehman, Constance D.; Andre, Michael P.; Fecht, Barbara A.; Johansen, Jennifer M.; Shelby, Ronald L.; Shelby, Jerod O.

    1999-05-01

    Ultrasound is an attractive modality for adjunctive characterization of certain breast lesions, but it is not considered specific for cancer and it is not recommended for screening. An imaging technique remarkably different from pulse-echo ultrasound, termed Optical SonographyTM (Advanced Diagnostics, Inc.), uses the through-transmission signal. The method was applied to breast examinations in 41 asymptomatic and symptomatic women ranging in age from 18 to 83 years to evaluate this imaging modality for detection and characterization of breast disease and normal tissue. This approach uses coherent sound and coherent light to produce real-time, large field-of-view images with pronounced edge definition in soft tissues of the body. The system patient interface was modified to improve coupling to the breast and bring the chest wall to within 3 cm of the sound beam. System resolution (full width half maximum of the line-spread function) was 0.5 mm for a swept-frequency beam centered at 2.7 MHz. Resolution degrades slightly in the periphery of the very large 15.2-cm field of view. Dynamic range of the reconstructed 'raw' images (no post processing) was 3000:1. Included in the study population were women with dense parenchyma, palpable ductal carcinoma in situ with negative mammography, superficial and deep fibroadenomas, and calcifications. Successful breast imaging was performed in 40 of 41 women. These images were then compared with images generated using conventional X-ray mammography and pulse-echo ultrasound. Margins of lesions and internal textures were particularly well defined and provided substantial contrast to fatty and dense parenchyma. In two malignant lesions, Optical SonographyTM appeared to approximate more closely tumor extent compared to mammography than pulse-echo sonography. These preliminary studies indicate the method has unique potential for detecting, differentiating, and guiding the biopsy of breast lesions using real-time acoustical holography.

  10. Evaluating the Effectiveness of an Ultrasonic Acoustic Deterrent for Reducing Bat Fatalities at Wind Turbines.

    PubMed

    Arnett, Edward B; Hein, Cris D; Schirmacher, Michael R; Huso, Manuela M P; Szewczak, Joseph M

    2013-01-01

    Large numbers of bats are killed by wind turbines worldwide and minimizing fatalities is critically important to bat conservation and acceptance of wind energy development. We implemented a 2-year study testing the effectiveness of an ultrasonic acoustic deterrent for reducing bat fatalities at a wind energy facility in Pennsylvania. We randomly selected control and treatment turbines that were searched daily in summer and fall 2009 and 2010. Estimates of fatality, corrected for field biases, were compared between treatment and control turbines. In 2009, we estimated 21-51% fewer bats were killed per treatment turbine than per control turbine. In 2010, we determined an approximate 9% inherent difference between treatment and control turbines and when factored into our analysis, variation increased and between 2% more and 64% fewer bats were killed per treatment turbine relative to control turbines. We estimated twice as many hoary bats were killed per control turbine than treatment turbine, and nearly twice as many silver-haired bats in 2009. In 2010, although we estimated nearly twice as many hoary bats and nearly 4 times as many silver-haired bats killed per control turbine than at treatment turbines during the treatment period, these only represented an approximate 20% increase in fatality relative to the pre-treatment period for these species when accounting for inherent differences between turbine sets. Our findings suggest broadband ultrasound broadcasts may reduce bat fatalities by discouraging bats from approaching sound sources. However, effectiveness of ultrasonic deterrents is limited by distance and area ultrasound can be broadcast, in part due to rapid attenuation in humid conditions. We caution that an operational deterrent device is not yet available and further modifications and experimentation are needed. Future efforts must also evaluate cost-effectiveness of deterrents in relation to curtailment strategies to allow a cost-benefit analysis for

  11. Passenger comfort technology for system decision making

    NASA Technical Reports Server (NTRS)

    Conner, D. W.

    1980-01-01

    Decisions requiring passenger comfort technology were shown to depend on: the relationship between comfort and other factors (e.g., cost, urgency, alternate modes) in traveler acceptance of the systems, serving a selected market require technology to quantify effects of comfort versus offsetting factors in system acceptance. Public predict the maximum percentage of travelers who willingly accept the overall comfort of any trip ride. One or the other of these technology requirements apply to decisions on system design, operation and maintenance.

  12. Property evaluation of thermal sprayed metallic coating by acoustic emission analysis

    SciTech Connect

    Ishida, Asako; Mizutani, Yoshihiro; Takemoto, Mikio; Ono, Kanji

    2000-03-01

    The authors analyzed acoustic emission signals from plasma sprayed sheets by first obtaining the Young's modulus, Poisson's ratio, and density. The sheets of a high Cr-Ni alloy (55Cr-41Ni-Mo, Si, B) were made by low pressure plasma spraying (LPPS) and heat treated. Utilizing laser induced surface acoustic waves (SAWs), the group velocity dispersion data of Rayleigh waves was obtained and matched to that computed by Adler's matrix transfer method. They monitored the acoustic emissions (Lamb waves) produced by microfractures in free standing as sprayed coating subjected to bending. Fast cleavage type microfracture with source rise time of around 2 {micro}s occurred as precursors to the final brittle fracture. The velocity and time-frequency amplitude spectrograms (wavelet contour maps) of the Lamb waves were utilized for the source location and fracture kinetic analyses.

  13. Field evaluation of boat-mounted acoustic Doppler instruments used to measure streamflow

    USGS Publications Warehouse

    Mueller, D.S.; ,

    2003-01-01

    The use of instruments based on the Doppler principle for measuring water velocity and computing discharge is common within the U.S. Geological Survey (USGS). The instruments and software have changed appreciably during the last 5 years; therefore, the USGS has begun field validation of the instruments used to make discharge measurements from a moving boat. Instruments manufactured by SonTek/YSI and RD Instruments, Inc. were used to collect discharge data at five different sites. One or more traditional discharge measurements were made using a Price AA current meter and standard USGS procedures concurrent with the acoustic instruments at each site. Discharges measured with the acoustic instruments were compared with discharges measured with Price AA current meters and the USGS stage-discharge rating for each site. The mean discharges measured by each acoustic instrument were within 5 percent of the Price AA-based measurement and (or) discharge from the stage-discharge rating.

  14. JV Task 110 - Evaluation of an Acoustic Single-Fluid Nozzle for Oil Combustion

    SciTech Connect

    Kevin Galbreath; Jay Gunderson; James Tibbetts; Lingbu Kong

    2007-08-01

    Two residual (No. 6 fuel) oils from Texas and North Dakota with very different chemical compositions and physical properties were burned at similar injection rates ({approx}28 lb/hr) in a pilot-scale (550,000 Btu/hr) combustion test facility unit using conventional dual-fluid and Kimberly-Clark (K-C) acoustic nozzles to compare flame characteristics, gaseous and fly ash emissions, and fly ash morphological and chemical characteristics. The K-C acoustic nozzle supplied a more consistent oil feed rate to the furnace relative to the conventional dual-fluid nozzle. This consistency in oil flow reduced the variability in NO{sub x}, SO{sub 2}, CO{sub 2}, and O{sub 2} flue gas concentrations. K-C nozzle injection, however, produced a more carbon-rich residual oil fly ash (ROFA) relative to the conventional nozzle. The K-C acoustic nozzle promoted oil atomization and extended the flame higher in the furnace so that the residence time of the residual oil was greatly reduced. The lack of oil residence time in the furnace contributed to the incomplete combustion performance of the K-C acoustic nozzle. On average, the K-C acoustic nozzle reduced NO{sub x} emissions from burning the Texas and North Dakota oils by 66% and 33%, respectively. Late in the test program, it was discovered that a significant increase in power to the K-C acoustic nozzle improved combustion efficiency, flame stability, and reduced the amount of unburned carbon in ROFA. The unburned carbon particles were smaller, generally about 50 {micro}m in diameter, as a result of the increase in power to the K-C nozzle. Additional optimization of the K-C nozzle at higher power in a larger furnace has the potential to further improve combustion efficiency.

  15. Comfort, sustainability, and workflow improved.

    PubMed

    Seeney, Brett

    2015-02-01

    Brett Seeney, BEng Hons, CEng, FIHEEM, MCIBSE, an associate at WSP in Melbourne reports, in an article first published in the IFHE Digest 2014, on a major redevelopment scheme at the Echuca Regional Health Hospital in Australia's northern Victoria. The project innovatively harnessed the latest building services engineering technology to help the hospital operate more in a more sustainable and efficient way, while simultaneously improving comfort for patients, visitors, and staff.

  16. Uncertainty Analysis of Thermal Comfort Parameters

    NASA Astrophysics Data System (ADS)

    Ribeiro, A. Silva; Alves e Sousa, J.; Cox, Maurice G.; Forbes, Alistair B.; Matias, L. Cordeiro; Martins, L. Lages

    2015-08-01

    International Standard ISO 7730:2005 defines thermal comfort as that condition of mind that expresses the degree of satisfaction with the thermal environment. Although this definition is inevitably subjective, the Standard gives formulae for two thermal comfort indices, predicted mean vote ( PMV) and predicted percentage dissatisfied ( PPD). The PMV formula is based on principles of heat balance and experimental data collected in a controlled climate chamber under steady-state conditions. The PPD formula depends only on PMV. Although these formulae are widely recognized and adopted, little has been done to establish measurement uncertainties associated with their use, bearing in mind that the formulae depend on measured values and tabulated values given to limited numerical accuracy. Knowledge of these uncertainties are invaluable when values provided by the formulae are used in making decisions in various health and civil engineering situations. This paper examines these formulae, giving a general mechanism for evaluating the uncertainties associated with values of the quantities on which the formulae depend. Further, consideration is given to the propagation of these uncertainties through the formulae to provide uncertainties associated with the values obtained for the indices. Current international guidance on uncertainty evaluation is utilized.

  17. Acoustic Radiation Force Impulse Imaging for Noninvasive Evaluation of Renal Parenchyma Elasticity: Preliminary Findings

    PubMed Central

    Xu, Hui-Xiong; Peng, Ai; Zhang, Yi-Feng; Liu, Lin-Na

    2013-01-01

    Objective To evaluate the diagnostic value of acoustic radiation force impulse (ARFI) to test the elasticity of renal parenchyma by measuring the shear wave velocity (SWV) which might be used to detect chronic kidney disease (CKD). Methods 327 healthy volunteers and 64 CKD patients were enrolled in the study. The potential influencing factors and measurement reproducibility were evaluated in the healthy volunteers. Correlations between SWV and laboratory tests were analyzed in CKD patients.?Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance of ARFI. Results The SWV of healthy volunteers correlated significantly to age (r = −0.22, P<0.001, n = 327) and differed significantly between men and women (2.06±0.48 m/s vs. 2.2±0.52 m/s, P = 0.018, n = 327). However, it did not correlate significantly to height, weight, body mass index, waistline, kidney dimension and the depth for SWV measurement (n = 30). Inter- and intraobserver agreement expressed as intraclass coefficient correlation were 0.64 (95% CI: 0.13 to 0.82, P = 0.011) and 0.6 (95% CI: 0.31 to 0.81, P = 0.001) (n = 40). The mean SWV in healthy volunteers was 2.15±0.51 m/s, while was 1.81±0.43 m/s, 1.79±0.29 m/s, 1.81±0.44 m/s, 1.64±0.55 m/s, and 1.36±0.17 m/s for stage 1, 2, 3, 4 and 5 in CKD patients respectively. The SWV was significantly higher for healthy volunteers compared with each stage in CKD patients. ARFI could not predict the different stages of CKD except stage 5. In CKD patients, SWV correlated to e-GFR (r = 0.3, P = 0.018), to urea nitrogen (r =  −0.3, P = 0.016), and to creatinine (r =  −0.41, P = 0.001). ROC analyses indicated that the area under the ROC curve was 0.752 (95% CI: 0.704 to 0.797) (P<0.001). The cut-off value for predicting CKD was 1.88 m/s (sensitivity 71.87% and specificity 69.69%). Conclusion ARFI may be a potentially useful tool in detecting CKD. PMID

  18. Acoustic and perceptual evaluation of category goodness of /t/ and /k/ in typical and misarticulated children's speech.

    PubMed

    Strömbergsson, Sofia; Salvi, Giampiero; House, David

    2015-06-01

    This investigation explores perceptual and acoustic characteristics of children's successful and unsuccessful productions of /t/ and /k/, with a specific aim of exploring perceptual sensitivity to phonetic detail, and the extent to which this sensitivity is reflected in the acoustic domain. Recordings were collected from 4- to 8-year-old children with a speech sound disorder (SSD) who misarticulated one of the target plosives, and compared to productions recorded from peers with typical speech development (TD). Perceptual responses were registered with regards to a visual-analog scale, ranging from "clear [t]" to "clear [k]." Statistical models of prototypical productions were built, based on spectral moments and discrete cosine transform features, and used in the scoring of SSD productions. In the perceptual evaluation, "clear substitutions" were rated as less prototypical than correct productions. Moreover, target-appropriate productions of /t/ and /k/ produced by children with SSD were rated as less prototypical than those produced by TD peers. The acoustical modeling could to a large extent discriminate between the gross categories /t/ and /k/, and scored the SSD utterances on a continuous scale that was largely consistent with the category of production. However, none of the methods exhibited the same sensitivity to phonetic detail as the human listeners.

  19. Edge shape and comfort of rigid lenses.

    PubMed

    La Hood, D

    1988-08-01

    One of the main factors determining the comfort of a rigid contact lens is the shape of the edge. The comfort of four different contact lens edge shapes was assessed with four unadapted subjects in a randomized masked trial. Lenses with well rounded anterior edge profiles were found to be significantly more comfortable than lenses with square anterior edges. There was no significant difference in subjective comfort between a rounded and square posterior edge profile. The results suggest that the interaction of the edge with the eyelid is more important in determining comfort than edge effects on the cornea, when lenses are fitted according to a corneal alignment philosophy. PMID:3177585

  20. An evaluation study of mycelium based acoustic absorbers grown on agricultural by-product substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research examines the use of a novel new renewable resource in acoustic absorption applications. The material under test is based on the fruiting body of fungi, a mushroom, in the phylum of Basidiomycetes, which are grown on semi-hydrophobic substrates such as cotton by-products, leaves, sticks...

  1. Evaluation of near-surface stress distributions in dissimilar welded joint by scanning acoustic microscopy.

    PubMed

    Kwak, Dong Ryul; Yoshida, Sanichiro; Sasaki, Tomohiro; Todd, Judith A; Park, Ik Keun

    2016-04-01

    This paper presents the results from a set of experiments designed to ultrasonically measure the near surface stresses distributed within a dissimilar metal welded plate. A scanning acoustic microscope (SAM), with a tone-burst ultrasonic wave frequency of 200 MHz, was used for the measurement of near surface stresses in the dissimilar welded plate between 304 stainless steel and low carbon steel. For quantitative data acquisition such as leaky surface acoustic wave (leaky SAW) velocity measurement, a point focus acoustic lens of frequency 200 MHz was used and the leaky SAW velocities within the specimen were precisely measured. The distributions of the surface acoustic wave velocities change according to the near-surface stresses within the joint. A three dimensional (3D) finite element simulation was carried out to predict numerically the stress distributions and compare with the experimental results. The experiment and FE simulation results for the dissimilar welded plate showed good agreement. This research demonstrates that a combination of FE simulation and ultrasonic stress measurements using SAW velocity distributions appear promising for determining welding residual stresses in dissimilar material joints.

  2. Implosion of an underwater spark-generated bubble and acoustic energy evaluation using the Rayleigh model.

    PubMed

    Buogo, Silvano; Cannelli, Giovanni B

    2002-06-01

    The growth, collapse, and rebound of a vapor bubble generated by an underwater spark is studied by means of high-speed cinematography, simultaneously acquiring the emitted acoustic signature. Video recordings show that the growth and collapse phases are nearly symmetrical during the first two or three cycles, the bubble shape being approximately spherical. After 2-3 cycles the bubble behavior changes from a collapsing/rebounding regime with sound-emitting implosions to a pulsating regime with no implosions. The motion of the bubble wall during the first collapses was found to be consistent with the Rayleigh model of a cavity in an incompressible liquid, with the inclusion of a vapor pressure term at constant temperature within each bubble cycle. An estimate of the pressure inside the bubble is obtained measuring the collapse time and maximum radius, and the amount of energy converted into acoustical energy upon each implosion is deduced. The resulting value of acoustic efficiency was found to be in agreement with measurements based on the emitted acoustic pulse.

  3. Evaluation of acoustical conditions for speech communication in working elementary school classrooms.

    PubMed

    Sato, Hiroshi; Bradley, John S

    2008-04-01

    Detailed acoustical measurements were made in 41 working elementary school classrooms near Ottawa, Canada to obtain more representative and more accurate indications of the acoustical quality of conditions for speech communication during actual teaching activities. This paper describes the room acoustics characteristics and noise environment of 27 traditional rectangular classrooms from the 41 measured rooms. The purpose of the work was to better understand how to improve speech communication between teachers and students. The study found, that on average, the students experienced: teacher speech levels of 60.4 dB A, noise levels of 49.1 dB A, and a mean speech-to-noise ratio of 11 dB A during teaching activities. The mean reverberation time in the occupied classrooms was 0.41 s, which was 10% less than in the unoccupied rooms. The reverberation time measurements were used to determine the average absorption added by each student. Detailed analyses of early and late-arriving speech sounds showed these sound levels could be predicted quite accurately and suggest improved approaches to room acoustics design.

  4. A novel algorithm for buried target detection evaluated on a collection of seismo-acoustic data

    NASA Astrophysics Data System (ADS)

    Malof, Jordan M.; Knox, Mary; Torrione, Peter A.; Collins, Leslie M.; Morton, Kenneth D.

    2014-06-01

    A recently validated technique for buried target detection relies on applying an acoustic stimulus signal to a patch of earth and then measuring its seismic (vibrational) response using a laser Doppler vibrometer (LDV). Target detection in this modality often relies on estimating the acoustic-to-seismic coupling ratio (A/S ratio) of the ground, which is altered by the presence of a buried target. For this study, LDV measurements were collected over patches of earth under varying environmental conditions using a known stimulus. These observations are then used to estimate the performance of several methods to discriminate between target and non-target patches. The first part of the study compares the performance of human observers against a set of established seismo-acoustic features from the literature. The simple features are based on previous studies where statistics on the Fourier transform of the acoustic-to-seismic transfer function estimate are measured. The human observers generally offered much better detection performance than any established feature. One weakness of the Fourier features is their inability to utilize local spatiotemporal target cues. To address these weaknesses, a novel automatic detection algorithm is proposed which uses a multi-scale blob detector to identify suspicious regions in time and space. These suspicious spatiotemporal locations are then clustered and assigned a decision statistic based on the confidence and number of cluster members. This method is shown to improve performance over the established Fourier statistics, resulting in performance much closer to the human observers.

  5. Evaluation of Mycelium Based Acoustic Absorbers Grown on Select Agricultural Byproduct Substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research examines the use of a novel new renewable resource in acoustic absorption applications. The material under test is based on the fruiting body of fungi, a mushroom, in the phylum of Basidiomycetes, which are grown on semi-hydrophobic substrates such as cotton byproducts, leaves, sticks ...

  6. Implosion of an underwater spark-generated bubble and acoustic energy evaluation using the Rayleigh model.

    PubMed

    Buogo, Silvano; Cannelli, Giovanni B

    2002-06-01

    The growth, collapse, and rebound of a vapor bubble generated by an underwater spark is studied by means of high-speed cinematography, simultaneously acquiring the emitted acoustic signature. Video recordings show that the growth and collapse phases are nearly symmetrical during the first two or three cycles, the bubble shape being approximately spherical. After 2-3 cycles the bubble behavior changes from a collapsing/rebounding regime with sound-emitting implosions to a pulsating regime with no implosions. The motion of the bubble wall during the first collapses was found to be consistent with the Rayleigh model of a cavity in an incompressible liquid, with the inclusion of a vapor pressure term at constant temperature within each bubble cycle. An estimate of the pressure inside the bubble is obtained measuring the collapse time and maximum radius, and the amount of energy converted into acoustical energy upon each implosion is deduced. The resulting value of acoustic efficiency was found to be in agreement with measurements based on the emitted acoustic pulse. PMID:12083190

  7. Operators' perception of comfort in two tractor cabs.

    PubMed

    Ferrari, E; Cavallo, E

    2013-01-01

    Workspace characteristics affect the perceived comfort level of the operator and uncomfortable working conditions have been found to have a negative impact on productivity and safety. The comfort of the operator is increasingly recognized by manufacturers as a product's added value. Comfort can positively distinguish a product and increase its competitiveness. The concept of comfort is controversial, and a clear operational definition is missing. Nevertheless, it is widely accepted that comfort is a subjective phenomenon that can be evaluated by the final users. In this study, comfort aspects of the tractor workspace interior (i.e., the cab) were investigated. Users with various levels of expertise and two medium-power utility tractors of different brands were used in a 2 x 2 mixed-factorial experimental design. Participants were involved in a dynamic assessment of the cabs, and their opinions about the different workspaces were collected through a questionnaire. Additionally, objective measurements were taken on both tractors, and subjective data were compared with objective data. Results indicate significant differences in terms of the ease of locating and operating the controls (i.e., rear-mounted three-point linkage, hydraulic system, and power take-off), the ease of starting the tractor, the ease exiting the cab, the required level of concentration in executing the tasks, the adequacy of lateral visibility from the driving station, and the level of noise at the operator's position. This article provides guidance for improving the comfort of tractor workspace interiors. Agricultural machinery manufactures would benefit from research results, differentiating themselves from competitors. PMID:23600166

  8. Operators' perception of comfort in two tractor cabs.

    PubMed

    Ferrari, E; Cavallo, E

    2013-01-01

    Workspace characteristics affect the perceived comfort level of the operator and uncomfortable working conditions have been found to have a negative impact on productivity and safety. The comfort of the operator is increasingly recognized by manufacturers as a product's added value. Comfort can positively distinguish a product and increase its competitiveness. The concept of comfort is controversial, and a clear operational definition is missing. Nevertheless, it is widely accepted that comfort is a subjective phenomenon that can be evaluated by the final users. In this study, comfort aspects of the tractor workspace interior (i.e., the cab) were investigated. Users with various levels of expertise and two medium-power utility tractors of different brands were used in a 2 x 2 mixed-factorial experimental design. Participants were involved in a dynamic assessment of the cabs, and their opinions about the different workspaces were collected through a questionnaire. Additionally, objective measurements were taken on both tractors, and subjective data were compared with objective data. Results indicate significant differences in terms of the ease of locating and operating the controls (i.e., rear-mounted three-point linkage, hydraulic system, and power take-off), the ease of starting the tractor, the ease exiting the cab, the required level of concentration in executing the tasks, the adequacy of lateral visibility from the driving station, and the level of noise at the operator's position. This article provides guidance for improving the comfort of tractor workspace interiors. Agricultural machinery manufactures would benefit from research results, differentiating themselves from competitors.

  9. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Articles Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    NASA Technical Reports Server (NTRS)

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    It is important to realize that some test-articles may have significant sound absorption that may challenge the acoustic power capabilities of a test facility. Therefore, to mitigate this risk of not being able to meet the customers target spectrum, it is prudent to demonstrate early-on an increased acoustic power capability which compensates for this test-article absorption. This paper describes a concise method to reduce this risk when testing aerospace test-articles which have significant absorption. This method was successfully applied during the SpaceX Falcon 9 Payload Fairing acoustic test program at the NASA Glenn Research Center Plum Brook Stations RATF.

  10. An evaluation of the maximum tag burden for implantation of acoustic transmitters in juvenile Chinook salmon

    SciTech Connect

    Brown, Richard S.; Harnish, Ryan A.; Carter, Kathleen M.; Boyd, James W.; Deters, Katherine A.; Eppard, M. B.

    2010-04-01

    Abstract.—The influence of a surgically implanted acoustic micro-transmitter and passive integrated transponder (PIT) tag on the growth and survival of hatchery-reared juvenile Chinook salmon was examined. Growth and survival were compared between treatment (implanted) and control fish within three fork length (FL) size groups (80-89, 90-99, and 100-109 mm). The acoustic micro-transmitter and PIT tag implanted in our study had a combined weight of 0.74 g. Weights of study fish ranged from 4.7 to 16.3 g for treatment fish and from 5.1 to 16.8 g for control fish. The burden for the combined acoustic and PIT tag experienced by implanted fish ranged from 8.8% to 15.7% for the 80-89 mm FL group, 6.0-10.9% for the 90-99 mm FL group, and 4.5-8.6% for the 100-109 mm FL group. Results indicated that growth and survival were size-dependent among implanted juvenile Chinook salmon. Significant differences in growth rate and survival were observed between treatment and control fish in the 80-89 mm FL group. Within this group, growth of fish smaller than 88.5 mm FL (tag burden > 10.0%) was negatively affected by the implantation or presence of an acoustic micro-transmitter and PIT tag. Survival of fish in the 90-99 mm FL group did not differ between treatment and control fish. However, survival of implanted fish within this size group that were smaller than 97.2 mm FL (tag burden > 7.4%) was negatively influenced. These results indicate that the burden of an acoustic micro-transmitter and PIT tag should be maintained at or below about 7.0% for studies that use hatchery-reared juvenile Chinook salmon.

  11. Fundamental Study on the Effect of High Frequency Vibration on Ride Comfort

    NASA Astrophysics Data System (ADS)

    Nakagawa, Chizuru; Shimamune, Ryohei; Watanabe, Ken; Suzuki, Erimitsu

    To develop a more suitable method of evaluating ride comfort of high speed trains, a fundamental study was conducted on sensitivity of passengers to various frequencies of vibration with respect to ride comfort. Experiments were performed on 55 subjects using an electrodynamic vibration system that can generate vibrations in the frequency range of 1 to 80 Hz in the vertical direction. Results of experiments indicated that the subjects tend to experience greater discomfort when exposed to high frequency vibrations than that presumed by the conventional Japanese ride comfort assessment method, the "Ride Comfort Level."

  12. Speakers' comfort and voice level variation in classrooms: laboratory research.

    PubMed

    Pelegrín-García, David; Brunskog, Jonas

    2012-07-01

    Teachers adjust their voice levels under different classroom acoustics conditions, even in the absence of background noise. Laboratory experiments have been conducted in order to understand further this relationship and to determine optimum room acoustic conditions for speaking. Under simulated acoustic environments, talkers do modify their voice levels linearly with the measure voice support, and the slope of this relationship is referred to as room effect. The magnitude of the room effect depends highly on the instruction used and on the individuals. Group-wise, the average room effect ranges from -0.93 dB/dB, with free speech, to -0.1 dB/dB with other less demanding communication tasks as reading and talking at short distances. The room effect for some individuals can be as strong as -1.7 dB/dB. A questionnaire investigation showed that the acoustic comfort for talking in classrooms, in the absence of background noise, is correlated to the decay times derived from an impulse response measured from the mouth to the ears of a talker, and that there is a maximum of preference for decay times between 0.4 and 0.5 s. Teachers with self-reported voice problems prefer higher decay times to speak in than their healthy colleagues.

  13. Coupling of the Models of Human Physiology and Thermal Comfort

    NASA Astrophysics Data System (ADS)

    Pokorny, J.; Jicha, M.

    2013-04-01

    A coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. A coupling combines a modified Tanabe model of human physiology and thermal comfort model developed by Zhang. The Coupled model allows predicting the thermal sensation and comfort of both local and overall from local boundary conditions representing ambient and personal factors. The aim of this study was to compare prediction of the Coupled model with the Fiala model prediction and experimental data. Validation data were taken from the literature, mainly from the validation manual of software Theseus-FE [1]. In the paper validation of the model for very light physical activities (1 met) indoor environment with temperatures from 12 °C up to 48 °C is presented. The Coupled model predicts mean skin temperature for cold, neutral and warm environment well. However prediction of core temperature in cold environment is inaccurate and very affected by ambient temperature. Evaluation of thermal comfort in warm environment is supplemented by skin wettedness prediction. The Coupled model is designed for non-uniform and transient environmental conditions; it is also suitable simulation of thermal comfort in vehicles cabins. The usage of the model is limited for very light physical activities up to 1.2 met only.

  14. Band-limited Green's Functions for Quantitative Evaluation of Acoustic Emission Using the Finite Element Method

    NASA Technical Reports Server (NTRS)

    Leser, William P.; Yuan, Fuh-Gwo; Leser, William P.

    2013-01-01

    A method of numerically estimating dynamic Green's functions using the finite element method is proposed. These Green's functions are accurate in a limited frequency range dependent on the mesh size used to generate them. This range can often match or exceed the frequency sensitivity of the traditional acoustic emission sensors. An algorithm is also developed to characterize an acoustic emission source by obtaining information about its strength and temporal dependence. This information can then be used to reproduce the source in a finite element model for further analysis. Numerical examples are presented that demonstrate the ability of the band-limited Green's functions approach to determine the moment tensor coefficients of several reference signals to within seven percent, as well as accurately reproduce the source-time function.

  15. Evaluation of Fracture in Concrete with Recycled Aggregate by Acoustic Emission

    NASA Astrophysics Data System (ADS)

    Nishibata, Sayaka; Watanabe, Takeshi; Hashimoro, Chikanori; Kohno, Kiyoshi

    This research revealed fracture behavior of concrete in using recycled aggregates by Acoustic Emission as one of the Non-destructive Inspection. The phenomenon of acoustic emission (AE) is the propagation of elastic waves generated from a source, known as a micro-crack in an elastic material. There were taken to use low-treated recycled aggregate, crushed returned ready mixed concrete for aggregate and normal aggregate. Examination measured AE under the uniaxial compression test. The condition of load is repeated loading. As a result, fracture behavior due to low treated recycled aggregate was detected by AE. It is clarified that AE of concrete with low treated recycled aggregate appeared in low stress level. It has been understood that difference of aggregates becomes clear from Kaiser effect in repeated loading. In relation between RA value and average frequency, it has been understood the adhesion properties of the cement paste in recycled aggregate are appreciable.

  16. Acoustic and vibration performance evaluations of a velocity sensing hull array

    NASA Astrophysics Data System (ADS)

    Cray, Benjamin A.; Christman, Russell A.

    1996-04-01

    Acoustic and vibration measurements were conducted at the Naval Undersea Warfare Center's Seneca Lake Facility to investigate the in situ signal response of a linear array of velocity sensors (sensors that measure either acoustic particle acceleration, velocity, or displacement have generically been denoted as velocity sensors) on a coating. The coating used at Seneca Lake consisted of air-voided elastomeric tiles with an overall coating thickness of approximately 3 inches. The accelerometer array and coating were mounted on the Seneca Lake Hull Fixture, which measures 33 feet lengthwise with an arc length of 20 feet. The fixture weighs approximately 30 tons. Specifically, measurements of in situ sensitivity, velocity reduction, reflection gain, array beam response, and equivalent planewave self-noise levels are presented.

  17. Teaching Children about Aspects of Comfort in the Built Environment

    ERIC Educational Resources Information Center

    Kowaltowski, Doris C. C. K.; Filho, Francisco Borges; Labaki, Lucila C.; Pina, Silvia A. Mikami G.; Bernardi, Nubia

    2004-01-01

    This article presents specific teaching material for the primary school level that introduces basic concepts of environmental comfort. The authors developed 2 booklets to make children aware of the built environment. Following a postoccupancy evaluation of state schools in the city of Campinas, in the state of Sao Paulo, Brazil, the research team…

  18. Effect of neck warming and cooling on thermal comfort

    NASA Technical Reports Server (NTRS)

    Williams, B. A.; Chambers, A. B.

    1972-01-01

    The potential use of local neck cooling in an area superficial to the cerebral arteries was evaluated by circulating cold or hot water through two copper disks held firmly against the neck. Subjective responses indicated that neck cooling improves the thermal comfort in a hot environment.

  19. Evaluation of Acoustic Emission NDE of Kevlar Composite Over Wrapped Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Horne, Michael R.; Madaras, Eric I.

    2008-01-01

    Pressurization and failure tests of small Kevlar/epoxy COPV bottles were conducted during 2006 and 2007 by Texas Research Institute Austin, Inc., at TRI facilities. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. Results of some of the tests indicate a possibility that AE can be used to track the stress-rupture degradation of COPV vessels.

  20. Initial Evaluation of Acoustic Emission SHM of PRSEUS Multi-bay Box Tests

    NASA Technical Reports Server (NTRS)

    Horne, Michael R.; Madaras, Eric I.

    2016-01-01

    A series of tests of the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) HWB Multi-Bay Test Article were conducted during the second quarter of 2015 at NASA Langley Research Center (LaRC) in the Combined Loads Test facility (COLTS). This report documents the Acoustic Emission (AE) data collected during those tests along with an initial analysis of the data. A more detailed analysis will be presented in future publications.

  1. Comfort studies of rail passengers

    PubMed Central

    Nicol, J. F.; Doré, C.; Weiner, J. S.; Lee, D. E.; Prestidge, S. P.; Andrews, M. J.

    1973-01-01

    Nicol, J. F., Doré, C., Weiner, J. S., Lee, D. E., Prestidge, S. P., and Andrews, M. J. (1973).British Journal of Industrial Medicine,30, 325-334. Comfort studies of rail passengers. A short series of trials is described in which a specimen car of the new High Density Rolling Stock was laden with passengers at different densities and under different environmental constraints, designed to simulate `shut-down' conditions. The results suggest that the limit for comfort, 21·8°C corrected effective temperature (CET), proposed by Bell and Watts (1971) is reasonable but that temperatures some 3 or 4°C higher can be tolerated without undue discomfort. The physiological limit for safety recommended by Bell and Watts is a CET of 30·6°C. This will be reached in less than 20 minutes if there is a power failure in warm conditions in crowded trains. An undesirable, possibly dangerous, level of discomfort will be experienced by passengers in ventilated but crowded trains after 30 minutes. In any case it is recommended that the globe temperature in a carriage should not exceed 30°C. Images PMID:4753715

  2. Stress-induced endocrine response and anxiety: the effects of comfort food in rats.

    PubMed

    Ortolani, Daniela; Garcia, Márcia Carvalho; Melo-Thomas, Liana; Spadari-Bratfisch, Regina Celia

    2014-05-01

    The long-term effects of comfort food in an anxiogenic model of stress have yet to be analyzed. Here, we evaluated behavioral, endocrine and metabolic parameters in rats submitted or not to chronic unpredictable mild stress (CUMS), with access to commercial chow alone or to commercial chow and comfort food. Stress did not alter the preference for comfort food but decreased food intake. In the elevated plus-maze (EPM) test, stressed rats were less likely to enter/remain in the open arms, as well as being more likely to enter/remain in the closed arms, than were control rats, both conditions being more pronounced in the rats given access to comfort food. In the open field test, stress decreased the time spent in the centre, independent of diet; neither stress nor diet affected the number of crossing, rearing or grooming episodes. The stress-induced increase in serum corticosterone was attenuated in rats given access to comfort food. Serum concentration of triglycerides were unaffected by stress or diet, although access to comfort food increased total cholesterol and glucose. It is concluded that CUMS has an anorexigenic effect. Chronic stress and comfort food ingestion induced an anxiogenic profile although comfort food attenuated the endocrine stress response. The present data indicate that the combination of stress and access to comfort food, common aspects of modern life, may constitute a link among stress, feeding behavior and anxiety.

  3. Simulator studies and psychophysical ride comfort models

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    An elementary psychophysical model to predict ride comfort was developed using flight and simulator data where subjects were exposed to six degrees of freedom. The model presumes that the comfort response is proportional to the logarithm of the stimulus above some threshold stimulus. In order to verify this concept of comfort modeling, it was necessary to obtain ride comfort data for single degree of freedom random motions and for combinations of random motions. Accordingly, a simulator program was performed at the NASA Langley Research Center to measure subjective comfort response ratings using one degree of freedom, two degrees of freedom, three degrees of freedom, and six degrees of freedom. An analysis of the single degree of freedom and two degrees of freedom data is presented. Preliminary models of ride comfort response for single degree of freedom random motions and for certain combinations of two degrees of freedom random motions were developed.

  4. Radiant heat and thermal comfort in vehicles.

    PubMed

    Devonshire, Joel M; Sayer, James R

    2005-01-01

    Infrared-reflective (IRR) treatment of automotive glass has been shown to reduce air temperature in vehicle cabins, thereby increasing fuel economy and occupant comfort. Its effect on radiant heat, however, may augment these benefits. In this study, the hypothesis that radiant heat affects subjective comfort ratings in a vehicle was tested. IRR films were systematically applied to the driver-side window of an outdoor stationary vehicle. In Phase 1, cabin air temperature was controlled while participants rated their thermal comfort. In Phase 2, air temperature was adjusted according to participants' responses. Results in Phase 1 showed that the IRR treatment improved thermal comfort on the left forearm, which was exposed to direct solar irradiance, but not whole-body thermal comfort. In Phase 2, participants indicated that they were comfortable at a higher air temperature (mean of 2.5 degrees F [1.4 degrees C]) with the IRR treatment than in the untreated condition. The results indicate that reducing radiant heat via IRR treatment affects subjective assessments of thermal comfort and allows occupants to maintain the same level of comfort in a warmer vehicle cabin. Applications of this research include future implementations of IRR treatment on automotive glass that may lead to greater fuel economy savings and occupant comfort than have previously been estimated.

  5. Quantitative evaluation of rejuvenators to restore embrittlement temperatures in oxidized asphalt mixtures using acoustic emission

    NASA Astrophysics Data System (ADS)

    Sun, Zhe; Farace, Nicholas; Arnold, Jacob; Behnia, Behzad; Buttlar, William G.; Reis, Henrique

    2015-03-01

    Towards developing a method capable to assess the efficiency of rejuvenators to restore embrittlement temperatures of oxidized asphalt binders towards their original, i.e., unaged values, three gyratory compacted specimens were manufactured with mixtures oven-aged for 36 hours at 135 °C. In addition, one gyratory compacted specimen manufactured using a short-term oven-aged mixture for two hours at 155 °C was used for control to simulate aging during plant production. Each of these four gyratory compacted specimens was then cut into two cylindrical specimen 5 cm thick for a total of six 36-hour oven-aged specimens and two short term aging specimens. Two specimens aged for 36 hours and the two short-term specimens were then tested using an acoustic emission approach to obtain base acoustic emission response of short-term and severely-aged specimens. The remaining four specimens oven-aged for 36 hours were then treated by spreading their top surface with rejuvenator in the amount of 10% of the binder by weight. These four specimens were then tested using the same acoustic emission approach after two, four, six, and eight weeks of dwell time. It was observed that the embrittlement temperatures of the short-term aged and severely oven-aged specimens were -25 °C and - 15 °C, respectively. It was also observed that after four weeks of dwell time, the rejuvenator-treated samples had recuperated the original embrittlement temperatures. In addition, it was also observed that the rejuvenator kept acting upon the binder after four weeks of dwell time; at eight weeks of dwell time, the specimens had an embrittlement temperature about one grade cooler than the embrittlement temperature corresponding to the short-term aged specimen.

  6. Evaluation of bottom trawls as compared to acoustics to assess adult Lake Herring (Coregonus artedi) abundance in Lake Superior

    USGS Publications Warehouse

    Stockwell, J.D.; Yule, D.L.; Gorman, O.T.; Isaac, E.J.; Moore, S.A.

    2006-01-01

    We compared density estimates from day bottom trawl tows against night midwater trawl tows and acoustic gear to test the hypothesis that adult lake herring (≥250 mm) are underestimated by day bottom trawl tows during the annual USGS spring fish community survey in Lake Superior. We found average density at nine nearshore stations was significantly higher at night (21.3 adult fish/ha) compared to day (1.0 adult fish/ha; p = 0.0119). At nine offshore stations, no lake herring were captured during the day but density averaged 39.6 adult fish/ha at night. At a lakewide scale (n = 18 stations), precision (relative standard error) was much better using night midwater trawls and acoustic gear (37%) compared to day bottom trawls (100%). Moderate sample size increases using the former methodology would likely bring precision within recommended levels (≤30%) for stock-recruit data sets. Our results suggest that 1) population abundances of adult lake herring in Lake Superior are much higher than previously considered, 2) the annual spring fish community survey may not provide a relative index of abundance of adult lake herring, 3) night midwater trawls and acoustic gear are necessary for assessing adult lake herring abundance, and 4) previous studies using lake herring data from the annual spring fish community survey need to be re-evaluated in light of these results. Lake herring appear to become progressively more pelagic and less susceptible to bottom trawling as they mature. Day bottom trawls appear to be an adequate tool for estimating relative density of age-1 recruits, although this method still suffers from relatively poor precision.

  7. Southeast Alaska Acoustic Measurement Facility (SEAFAC) environmental data base review, evaluation, and upgrade

    SciTech Connect

    Strand, J.A.; Skalski, J.R.; Faulkner, L.L.; Rodman, C.W.; Carlile, D.W.; Ecker, R.M.; Nicholls, A.K.; Ramsdell, J.V.; Scott, M.J.

    1986-04-01

    This report summarizes the principal issues of public concern, the adequacy of the environmental data base to answer the issues of concern, and the additional data collection required to support a National Environmental Policy Act (NEPA) review of the proposed Southeast Alaska Acoustic Measurement Facility (SEAFAC). The report is based on a review of the readily available environmental literature and a site visit. Representatives of local, state, and federal agencies were also interviewed for their personal insights and concerns not discovered during the literature review.

  8. Evaluation of Acoustic Emission SHM of PRSEUS Composite Pressure Cube Tests

    NASA Technical Reports Server (NTRS)

    Horne, Michael R.; Madaras, Eric I.

    2013-01-01

    A series of tests of the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) pressure cube were conducted during third quarter 2011 at NASA Langley Research Center (LaRC) in the Combined Loads Test facility (COLTS). This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. The AE signals of the later tests are consistent with the final failure progression through two of the pressure cube panels. Calibration tests and damage precursor AE indications, from preliminary checkout pressurizations, indicated areas of concern that eventually failed. Hence those tests have potential for vehicle health monitoring.

  9. Simultaneous evaluation of acoustic nonlinearity parameter and attenuation coefficients using the finite amplitude method

    SciTech Connect

    Zhang, Shuzeng; Li, Xiongbing; Jeong, Hyunjo Cho, Sungjong

    2015-07-15

    A novel method to determine acoustic parameters involved in measuring the nonlinearity parameter of fluids or solids is proposed. The approach is based on the measurement of fundamental and second harmonic pressures with a calibrated receiver, and on a nonlinear least squares data-fitting to multi-Gaussian beam (MGB) equations which explicitly define the attenuation and diffraction effects in the quasilinear regime. Results obtained in water validate the proposed method. The choice of suitable source pressure is discussed with regard to the quasilinear approximation involved. The attenuation coefficients are also acquired in nonlinear regime and their relations are discussed.

  10. Evaluation of an acoustic black hole’s structural characteristics using laser-generated Lamb waves

    NASA Astrophysics Data System (ADS)

    Yan, Shi-Ling; Lomonosov, A. M.; Shen, Zhong-Hua

    2016-02-01

    The interaction of laser-generated Lamb waves propagating in a thin aluminum plate with a two-dimensional (2D) acoustic black hole was studied experimentally and theoretically. The decrease in phase velocity due to the gradual decrease in thickness was validated. The focusing function of the structure was also studied in this work. Experiments were performed using a vibrometer. A scanning laser line source technique was used to generate a series of Lamb wave waveforms to obtain the dispersion spectrum through the 2D fast Fourier transform method. Using this method, the effect of structure on Lamb modes was studied.

  11. The environmental, health, and safety issues of acoustical materials: A strategy for finding, using, and evaluating information effectively

    NASA Astrophysics Data System (ADS)

    Bischel, Marsha S.

    2005-09-01

    Concern over the safety of our indoor environments has increased in recent years. The definition of safety has also evolved to include not just life safety issues such as fire, but issues such as mold growth, toxins, the emission of volatile organic compounds, seismic concerns, and ergonomic issues. Consequently, the understanding of product safety has become increasingly more complex. Simultaneously, there has been an explosion in the number of products available to specifiers, due largely to access to the World Wide Web by international manufacturers of all sizes. Some of these manufacturers may be unable to test all aspects of product safety, or simply may be unaware of safety regulations. Specifiers can no longer assume a product is inherently safe and must do their own evaluations of product safety attributes. This paper will lay out a basic methodology for finding, using, and evaluating environmental, health, and safety information on acoustical products in an effective manner.

  12. Aircraft IR/acoustic detection evaluation. Volume 2: Development of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft

    NASA Technical Reports Server (NTRS)

    Kraft, Robert E.

    1992-01-01

    The design and performance of a ground-based acoustic sensor system for the detection of subsonic jet-powered aircraft is described and specified. The acoustic detection system performance criteria will subsequently be used to determine target detection ranges for the subject contract. Although the defined system has never been built and demonstrated in the field, the design parameters were chosen on the basis of achievable technology and overall system practicality. Areas where additional information is needed to substantiate the design are identified.

  13. Acoustic and perceptual evaluation of Mandarin tone productions before and after perceptual training

    NASA Astrophysics Data System (ADS)

    Wang, Yue; Jongman, Allard; Sereno, Joan A.

    2003-02-01

    Training American listeners to perceive Mandarin tones has been shown to be effective, with trainees' identification improving by 21%. Improvement also generalized to new stimuli and new talkers, and was retained when tested six months after training [Y. Wang et al., J. Acoust. Soc. Am. 106, 3649-3658 (1999)]. The present study investigates whether the tone contrasts gained perceptually transferred to production. Before their perception pretest and after their post-test, the trainees were recorded producing a list of Mandarin words. Their productions were first judged by native Mandarin listeners in an identification task. Identification of trainees' post-test tone productions improved by 18% relative to their pretest productions, indicating significant tone production improvement after perceptual training. Acoustic analyses of the pre- and post-training productions further reveal the nature of the improvement, showing that post-training tone contours approximate native norms to a greater degree than pretraining tone contours. Furthermore, pitch height and pitch contour are not mastered in parallel, with the former being more resistant to improvement than the latter. These results are discussed in terms of the relationship between non-native tone perception and production as well as learning at the suprasegmental level.

  14. Evaluation of a multi-point method for determining acoustic impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Parrott, Tony L.

    1988-01-01

    An investigation was conducted to explore potential improvements provided by a Multi-Point Method (MPM) over the Standing Wave Method (SWM) and Two-Microphone Method (TMM) for determining acoustic impedance. A wave propagation model was developed to model the standing wave pattern in an impedance tube. The acoustic impedance of a test specimen was calculated from a best fit of this standing wave pattern to pressure measurements obtained along the impedance tube centerline. Three measurement spacing distributions were examined: uniform, random, and selective. Calculated standing wave patterns match the point pressure measurement distributions with good agreement for a reflection factor magnitude range of 0.004 to 0.999. Comparisons of results using 2, 3, 6, and 18 measurement points showed that the most consistent results are obtained when using at least 6 evenly spaced pressure measurements per half-wavelength. Also, data were acquired with broadband noise added to the discrete frequency noise and impedances were calculated using the MPM and TMM algorithms. The results indicate that the MPM will be superior to the TMM in the presence of significant broadband noise levels associated with mean flow.

  15. Acoustic mode coupling induced by nonlinear internal waves: evaluation of the mode coupling matrices and applications.

    PubMed

    Yang, T C

    2014-02-01

    This paper applies the mode coupling equation to calculate the mode-coupling matrix for nonlinear internal waves appearing as a train of solitons. The calculation is applied to an individual soliton up to second order expansion in sound speed perturbation in the Dyson series. The expansion is valid so long as the fractional sound speed change due to a single soliton, integrated over range and depth, times the wavenumber is smaller than unity. Scattering between the solitons are included by coupling the mode coupling matrices between the solitons. Acoustic fields calculated using this mode-coupling matrix formulation are compared with that obtained using a parabolic equation (PE) code. The results agree very well in terms of the depth integrated acoustic energy at the receivers for moving solitary internal waves. The advantages of using the proposed approach are: (1) The effects of mode coupling can be studied as a function of range and time as the solitons travel along the propagation path, and (2) it allows speedy calculations of sound propagation through a packet or packets of solitons saving orders of magnitude computations compared with the PE code. The mode coupling theory is applied to at-sea data to illustrate the underlying physics.

  16. Acoustic evaluation of the Helmholtz resonator treatment in the NASA Lewis 8- by 6-foot supersonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Heidelberg, Laurence J.; Gordon, Elliot B.

    1989-01-01

    The acoustic consequences of sealing the Helmholtz resonators of the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT) were experimentally evaluated. This resonator sealing was proposed in order to avoid entrapment of hydrogen during tests of advanced hydrogen-fueled engines. The resonators were designed to absorb energy in the 4- to 20-Hz range; thus, this investigation is primarily concerned with infrasound. Limited internal and external noise measurements were made at tunnel Mach numbers ranging from 0.5 to 2.0. Although the resonators were part of the acoustic treatment installed because of a community noise problem their sealing did not seem to indicate a reoccurrence of the problem would result. Two factors were key to this conclusion: (1) A large bulk treatment muffler downstream of the resonators was able to make up for much of the attenuation originally provided by the resonators, and (2) there was no noise source in the tunnel test section. The previous community noise problem occurred when a large ramjet was tested in an open-loop tunnel configuration. If a propulsion system producing high noise levels at frequencies of less than 10 Hz were tested, the conclusion on community noise would have to be reevaluated.

  17. A comparative evaluation of piezoelectric sensors for acoustic emission-based impact location estimation and damage classification in composite structures

    NASA Astrophysics Data System (ADS)

    Uprety, Bibhisha; Kim, Sungwon; Mathews, V. John; Adams, Daniel O.

    2015-03-01

    Acoustic Emission (AE) based Structural Health Monitoring (SHM) is of great interest for detecting impact damage in composite structures. Within the aerospace industry the need to detect and locate these events, even when no visible damage is present, is important both from the maintenance and design perspectives. In this investigation, four commercially available piezoelectric sensors were evaluated for usage in an AE-based SHM system. Of particular interest was comparing the acoustic response of the candidate piezoelectric sensors for impact location estimations as well as damage classification resulting from the impact in fiber-reinforced composite structures. Sensor assessment was performed based on response signal characterization and performance for active testing at 300 kHz and steel-ball drop testing using both aluminum and carbon/epoxy composite plates. Wave mode velocities calculated from the measured arrival times were found to be in good agreement with predictions obtained using both the Disperse code and finite element analysis. Differences in the relative strength of the received wave modes, the overall signal strengths and signal-to-noise ratios were observed through the use of both active testing as well as passive steel-ball drop testing. Further comparative is focusing on assessing AE sensor performance for use in impact location estimation algorithms as well as detecting and classifying damage produced in composite structures due to impact events.

  18. NOTE: Initial evaluation of acoustic reflectors for the preservation of sensitive abdominal skin areas during MRgFUS treatment

    NASA Astrophysics Data System (ADS)

    Gorny, Krzysztof R.; Chen, Shigao; Hangiandreou, Nicholas J.; Hesley, Gina K.; Woodrum, David A.; Brown, Douglas L.; Felmlee, Joel P.

    2009-04-01

    During MR-guided focused ultrasound (MRgFUS) treatments of uterine fibroids using ExAblate®2000 (InSightec, Haifa, Israel), individual tissue ablations are performed extracorporeally through the patient's abdomen using an annular array FUS transducer embedded within the MR table. Ultrasound intensities in the near field are below therapeutic levels and, under normal conditions, heating of the patient skin is minimal. However, increased absorption of ultrasound energy within sensitive skin areas or areas with differing acoustic properties, such as scars, may lead to skin burns and therefore these areas must be kept outside the near field of the FUS beam. Depending on their location and size the sensitive areas may either obstruct parts of the fibroid from being treated or prevent the entire MRgFUS treatment altogether. The purpose of this work is to evaluate acoustic reflector materials that can be applied to protect skin and the underlying sensitive areas. Reflection coefficients of cork (0.88) and foam (0.91) based materials were evaluated with a hydrophone. An ExAblate 2000 MRgFUS system was used to simulate clinical treatment with discs of reflector materials placed in a near field underneath a gel phantom. MR thermometry was used to monitor temperature elevations as well as the integrity of the focal spot. The phantom measurements showed acoustic shadow zones behind the reflectors with zone depths changing between 7 and 27 mm, for reflector disc diameters increasing from 10 to 30 mm (40 mm diameter discs completely blocked the FUS beam at the depth evaluated). The effects on thermal lesions due to the presence of the reflectors in the FUS beam were found to diminish with decreasing disc diameter and increasing sonication depth. For a 20 mm diameter disc and beyond 50 mm sonication depth, thermal lesions were minimally affected by the presence of the disc. No heating was observed on the skin side of the foam reflectors, as confirmed by measurements performed

  19. Thermal Comfort and Strategies for Energy Conservation.

    ERIC Educational Resources Information Center

    Rohles, Frederick H., Jr.

    1981-01-01

    Discusses studies in thermal comfort which served as the basis for the comfort standard. Examines seven variables in the human response to the thermal environment in terms of the ways in which they can be modified to conserve energy. (Author/MK)

  20. Classroom acoustics and hearing ability as determinants for perceived social climate and intentions to stay at work.

    PubMed

    Persson, Roger; Kristiansen, Jesper; Lund, Søren P; Shibuya, Hitomi; Nielsen, Per Møberg

    2013-01-01

    Background noise and room acoustics may impede social interactions by interfering with oral communication and other cognitive processes. Accordingly, recent research in school environments has showed that social relationships with peers and teachers are described more negatively in rooms with long reverberation times (RT). The purpose of this study was to investigate how RT and hearing ability (i.e., hearing thresholds [HT] and distortion product oto-acoustic emissions) were associated with school teachers' perceptions of the social climate at work and their intentions to stay on the job. School teachers (n = 107) from 10 schools that worked in classrooms classified by acoustical experts as "short RT" (3 schools, mean RT 0.41-0.47 s), "medium RT" (3 schools, mean RT 0.50-0.53 s), and "long RT" (4 schools, mean RT 0.59-0.73 s) were examined. Teachers who worked in classrooms with long RT perceived their social climate to be more competitive, conflict laden, and less relaxed and comfortable. They were more doubtful about staying on the job. Even if the teachers were generally satisfied with their work the results suggest that the comfort at work may have been further improved by acoustical interventions that focus on reducing sound reflections in the classrooms. Yet, due the study design and the novelty of the findings the potential practical significance of our observations remains to be evaluated.

  1. Children's exposure to indoor air in urban nurseries-part I: CO₂ and comfort assessment.

    PubMed

    Branco, P T B S; Alvim-Ferraz, M C M; Martins, F G; Sousa, S I V

    2015-07-01

    Indoor air quality (IAQ) in nurseries is an emerging case-study. Thus, this study, as the Part I of the larger study "Children's exposure to indoor air in urban nurseries", aimed to: i) evaluate nurseries' indoor concentrations of carbon dioxide (CO2), a global IAQ indicator, in class and lunch rooms; ii) assess indoor comfort parameters-temperature (T) and relative humidity (RH); and iii) analyse them according to guidelines and references for IAQ, comfort and children's health. Indoor continuous measurements were performed. Non-compliances with guidelines were found in comfort parameters, which could cause discomfort situations and also microbial proliferation. Exceedances in CO2 concentrations were also found and they were caused by poor ventilation and high classroom occupation. More efficient ventilation and control of comfort parameters, as well as to reduce occupation by reviewing Portuguese legislation on that matter, would certainly improve IAQ and comfort in nurseries and consequently safeguard children's health.

  2. Thermal comfort assessment in Moscow during the summer 2010

    NASA Astrophysics Data System (ADS)

    Malinina, Elizaveta; Konstantinov, Pavel

    2013-04-01

    Biometeorological indices are used to asses thermal comfort conditions and evaluate the influence of the weather on the human organism and health. Despite of the fact, that some biometeorological indices are already used in weather forecast, the assessment of these indices is especially important during the extreme weather conditions like continuous heat or cold waves. One of the very urgent issues in the applied climatology is the assessment of thermal comfort conditions in the urban areas, because nowadays more than half population of the planet lives there. Especially important is to study thermal comfort conditions in biggest and, thus, densely populated cities, because the effect of heat waves becomes stronger by the urban heat island effect. In July and August 2010 in the biggest city in Russia - Moscow, where more than 11 million people live, the longest and the strongest heat wave as well as the warmest day (29th of July 2010) were recorded since the meteorological observations in Russian capital were started. The main objective of this work is to evaluate the thermal comfort conditions of the warmest day in Moscow. For that purpose several biometeorological indices, particularly PET (physiological equivalent temperature), were analyzed and calculated for the warmest day in Russian capital. The calculations were done for the certain city canyon on the territory of the Moscow State University as well as for the places with natural vegetation. The results were compared with each other and, thus, the complex thermal comfort assessment was done. Also, the results of the calculations for the 29th of July 2010 were compared with the mean meteorological data for this period.

  3. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique.

    PubMed

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G; Alver, Ninel

    2015-08-05

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods.

  4. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique

    PubMed Central

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G.; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

  5. Analytical modeling of contact acoustic nonlinearity of guided waves and its application to evaluating severity of fatigue damage

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Su, Zhongqing

    2016-04-01

    Targeting quantitative estimate of fatigue damage, a dedicated analytical model was developed based on the modal decomposition method and the variational principle. The model well interprets the contact acoustic nonlinearity induced by a "breathing" crack in a two-dimensional scenario, and the nonlinear characteristics of guided ultrasonic waves (GUWs) (e.g., reflection, transmission, mode conversion and high-order generation) when GUWs traversing the crack. Based on the model, a second-order reflection index was defined. Using the index, a fatigue damage evaluation framework was established, showing demonstrated capacity of estimating the severity of fatigue damage in a quantitative manner. The approach, in principle, does not entail a benchmarking process against baseline signals pre-acquired from pristine counterparts. The results obtained using the analytical modeling were compared with those from finite element simulation, showing good coincidence. Limitations of the model were also discussed.

  6. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam with Emphasis on the Prototype Surface Flow Outlet, 2008

    SciTech Connect

    Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Deng, Zhiqun; Fu, Tao; Monter, Tyrell J.; Johnson, Gary E.; Khan, Fenton; Wilberding, Matthew C.; Cushing, Aaron W.; Zimmerman, Shon A.; Faber, Derrek M.; Durham, Robin E.; Townsend, Richard L.; Skalski, John R.; Kim, Jina; Fischer, Eric S.; Meyer, Matthew M.

    2009-12-01

    The main purpose of the study was to evaluate the performance of Top Spill Weirs installed at two spillbays at John Day Dam and evaluate the effectiveness of these surface flow outlets at attracting juvenile salmon away from the powerhouse and reducing turbine passage. The Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate survival of juvenile salmonids passing the dam and also for calculating performance metrics used to evaluate the efficiency and effectiveness of the dam at passing juvenile salmonids.

  7. A field evaluation of an external and neutrally buoyant acoustic transmitter for juvenile salmon: implications for estimating hydroturbine passage survival.

    PubMed

    Brown, Richard S; Deng, Z Daniel; Cook, Katrina V; Pflugrath, Brett D; Li, Xinya; Fu, Tao; Martinez, Jayson J; Li, Huidong; Trumbo, Bradly A; Ahmann, Martin L; Seaburg, Adam G

    2013-01-01

    Turbine-passed fish are exposed to rapid decreases in pressure which can cause barotrauma. The presence of an implanted telemetry tag increases the likelihood of injury or death from exposure to pressure changes, thus potentially biasing studies evaluating survival of turbine-passed fish. Therefore, a neutrally buoyant externally attached tag was developed to eliminate this bias in turbine passage studies. This new tag was designed not to add excess mass in water or take up space in the coelom, having an effective tag burden of zero with the goal of reducing pressure related biases to turbine survival studies. To determine if this new tag affects fish performance or susceptibility to predation, it was evaluated in the field relative to internally implanted acoustic transmitters (JSATS; Juvenile Salmon Acoustic Telemetry System) used widely for survival studies of juvenile salmonids. Survival and travel time through the study reach was compared between fish with either tag type in an area of high predation in the Snake and Columbia rivers, Washington. An additional group of fish affixed with neutrally-buoyant dummy external tags were implanted with passive integrated transponder (PIT) tags and recovered further downstream to assess external tag retention and injury. There were no significant differences in survival to the first detection site, 12 river kilometers (rkm) downstream of release. Travel times were also similar between groups. Conversely, externally-tagged fish had reduced survival (or elevated tag loss) to the second detection site, 65 rkm downstream. In addition, the retention study revealed that tag loss was first observed in fish recaptured approximately 9 days after release. Results suggest that this new tag may be viable for short term (<8 days) single-dam turbine-passage studies and under these situations, may alleviate the turbine passage-related bias encountered when using internal tags, however further research is needed to confirm this. PMID

  8. A field evaluation of an external and neutrally buoyant acoustic transmitter for juvenile salmon: implications for estimating hydroturbine passage survival.

    PubMed

    Brown, Richard S; Deng, Z Daniel; Cook, Katrina V; Pflugrath, Brett D; Li, Xinya; Fu, Tao; Martinez, Jayson J; Li, Huidong; Trumbo, Bradly A; Ahmann, Martin L; Seaburg, Adam G

    2013-01-01

    Turbine-passed fish are exposed to rapid decreases in pressure which can cause barotrauma. The presence of an implanted telemetry tag increases the likelihood of injury or death from exposure to pressure changes, thus potentially biasing studies evaluating survival of turbine-passed fish. Therefore, a neutrally buoyant externally attached tag was developed to eliminate this bias in turbine passage studies. This new tag was designed not to add excess mass in water or take up space in the coelom, having an effective tag burden of zero with the goal of reducing pressure related biases to turbine survival studies. To determine if this new tag affects fish performance or susceptibility to predation, it was evaluated in the field relative to internally implanted acoustic transmitters (JSATS; Juvenile Salmon Acoustic Telemetry System) used widely for survival studies of juvenile salmonids. Survival and travel time through the study reach was compared between fish with either tag type in an area of high predation in the Snake and Columbia rivers, Washington. An additional group of fish affixed with neutrally-buoyant dummy external tags were implanted with passive integrated transponder (PIT) tags and recovered further downstream to assess external tag retention and injury. There were no significant differences in survival to the first detection site, 12 river kilometers (rkm) downstream of release. Travel times were also similar between groups. Conversely, externally-tagged fish had reduced survival (or elevated tag loss) to the second detection site, 65 rkm downstream. In addition, the retention study revealed that tag loss was first observed in fish recaptured approximately 9 days after release. Results suggest that this new tag may be viable for short term (<8 days) single-dam turbine-passage studies and under these situations, may alleviate the turbine passage-related bias encountered when using internal tags, however further research is needed to confirm this.

  9. A Field Evaluation of an External and Neutrally Buoyant Acoustic Transmitter for Juvenile Salmon: Implications for Estimating Hydroturbine Passage Survival

    PubMed Central

    Brown, Richard S.; Deng, Z. Daniel; Cook, Katrina V.; Pflugrath, Brett D.; Li, Xinya; Fu, Tao; Martinez, Jayson J.; Li, Huidong; Trumbo, Bradly A.; Ahmann, Martin L.; Seaburg, Adam G.

    2013-01-01

    Turbine-passed fish are exposed to rapid decreases in pressure which can cause barotrauma. The presence of an implanted telemetry tag increases the likelihood of injury or death from exposure to pressure changes, thus potentially biasing studies evaluating survival of turbine-passed fish. Therefore, a neutrally buoyant externally attached tag was developed to eliminate this bias in turbine passage studies. This new tag was designed not to add excess mass in water or take up space in the coelom, having an effective tag burden of zero with the goal of reducing pressure related biases to turbine survival studies. To determine if this new tag affects fish performance or susceptibility to predation, it was evaluated in the field relative to internally implanted acoustic transmitters (JSATS; Juvenile Salmon Acoustic Telemetry System) used widely for survival studies of juvenile salmonids. Survival and travel time through the study reach was compared between fish with either tag type in an area of high predation in the Snake and Columbia rivers, Washington. An additional group of fish affixed with neutrally-buoyant dummy external tags were implanted with passive integrated transponder (PIT) tags and recovered further downstream to assess external tag retention and injury. There were no significant differences in survival to the first detection site, 12 river kilometers (rkm) downstream of release. Travel times were also similar between groups. Conversely, externally-tagged fish had reduced survival (or elevated tag loss) to the second detection site, 65 rkm downstream. In addition, the retention study revealed that tag loss was first observed in fish recaptured approximately 9 days after release. Results suggest that this new tag may be viable for short term (<8 days) single-dam turbine-passage studies and under these situations, may alleviate the turbine passage-related bias encountered when using internal tags, however further research is needed to confirm this. PMID

  10. Ride comfort analysis with physiological parameters for an e-health train.

    PubMed

    Lee, Youngbum; Shin, Kwangsoo; Lee, Sangjoon; Song, Yongsoo; Han, Sungho; Lee, Myoungho

    2009-12-01

    Transportation by train has numerous advantages over road transportation, especially with regard to energy efficiency, ecological features, safety, and punctuality. However, the contrast in ride comfort between standard road transportation and train travel has become a competitive issue. The ride comfort enhancement technology of tilting trains (TTX) is a particularly important issue in the development of the Korean high-speed railroad business. Ride comfort is now defined in international standards such as UIC13 and ISO2631. The Korean standards such as KSR9216 mainly address physical parameters such as vibration and noise. In the area of ride comfort, living quality parameter techniques have recently been considered in Korea, Japan, and Europe. This study introduces biological parameters, particularly variations in heart rate, as a more direct measure of comfort. Biological parameters are based on physiological responses rather than on purely external mechanical parameters. Variability of heart rate and other physiological parameters of passengers are measured in a simulation involving changes in the tilting angle of the TTX. This research is a preliminary study for the implementation of an e-health train, which would provide passengers with optimized ride comfort. The e-health train would also provide feedback on altered ride comfort situations that can improve a passenger's experience and provide a healthcare service on the train. The aim of this research was to develop a ride comfort evaluation system for the railway industry, the automobile industry, and the air industry. The degree of tilt correlated with heart rate, fatigue, and unrelieved alertness.

  11. Acoustical standards in engineering acoustics

    NASA Astrophysics Data System (ADS)

    Burkhard, Mahlon D.

    2001-05-01

    The Engineering Acoustics Technical Committee is concerned with the evolution and improvement of acoustical techniques and apparatus, and with the promotion of new applications of acoustics. As cited in the Membership Directory and Handbook (2002), the interest areas include transducers and arrays; underwater acoustic systems; acoustical instrumentation and monitoring; applied sonics, promotion of useful effects, information gathering and transmission; audio engineering; acoustic holography and acoustic imaging; acoustic signal processing (equipment and techniques); and ultrasound and infrasound. Evident connections between engineering and standards are needs for calibration, consistent terminology, uniform presentation of data, reference levels, or design targets for product development. Thus for the acoustical engineer standards are both a tool for practices, for communication, and for comparison of his efforts with those of others. Development of many standards depends on knowledge of the way products are put together for the market place and acoustical engineers provide important input to the development of standards. Acoustical engineers and members of the Engineering Acoustics arm of the Society both benefit from and contribute to the Acoustical Standards of the Acoustical Society.

  12. A survey of the acoustical quality of seventeen libraries at Princeton University

    NASA Astrophysics Data System (ADS)

    Markham, Benjamin

    2003-10-01

    The purpose of this study was to identify objective acoustic measures that correlate with the subjective responses of students and administrators to libraries at Princeton University. The motivation for this study was to determine what is necessary in order to provide a comfortable acoustic environment for users of a new science library to be built on campus. On 31 March 2003, Acentech, Incorporated evaluated 17 library spaces and interviewed a number of students and librarians at Princeton. Based on the results of the survey, the author proposes that a comfortable acoustic environment in a library is an environment that provides freedom from distraction; in other words, casual conversation and other noises in the library will not distract users reading or studying in the library. In order to provide such an environment, a library must have (1) appropriate levels of background sound, (2) a physical barrier between noise-producing and noise-sensitive sections, and (3) sufficient sound absorbing material in the space. Measured quantitative metrics support these conclusions.

  13. Evaluation of a gas chromatograph with a novel surface acoustic wave detector (SAW GC) for screening of volatile organic compounds in Hanford waste tank samples

    SciTech Connect

    Lockrem, L.L.

    1998-01-12

    A novel instrument, a gas chromatograph with a Surface Acoustic Wave Detector (SAW GC), was evaluated for the screening of organic compounds in Hanford tank headspace vapors. Calibration data were developed for the most common organic compounds, and the accuracy and precision were measured with a certified standard. The instrument was tested with headspace samples collected from seven Hanford waste tanks.

  14. Acoustic Remote Sensing

    NASA Astrophysics Data System (ADS)

    Dowling, David R.; Sabra, Karim G.

    2015-01-01

    Acoustic waves carry information about their source and collect information about their environment as they propagate. This article reviews how these information-carrying and -collecting features of acoustic waves that travel through fluids can be exploited for remote sensing. In nearly all cases, modern acoustic remote sensing involves array-recorded sounds and array signal processing to recover multidimensional results. The application realm for acoustic remote sensing spans an impressive range of signal frequencies (10-2 to 107 Hz) and distances (10-2 to 107 m) and involves biomedical ultrasound imaging, nondestructive evaluation, oil and gas exploration, military systems, and Nuclear Test Ban Treaty monitoring. In the past two decades, approaches have been developed to robustly localize remote sources; remove noise and multipath distortion from recorded signals; and determine the acoustic characteristics of the environment through which the sound waves have traveled, even when the recorded sounds originate from uncooperative sources or are merely ambient noise.

  15. Sound source information to improve cardiothoracic patients' comfort.

    PubMed

    Mackrill, Jamie; Cain, Rebecca; Jennings, Paul; England, Michelle

    Hospital sound has been well documented through acoustic measurement and the classification of its adverse effects on patients and nurses. However, little consideration has been given to how the perception of these unavoidable soundscapes can be improved. For instance, does a better understanding of the variety of sounds improve patients' feeling? This paper begins to answer this and documents a pilot questionnaire-based study looking at the effects and potential benefits of sound source information (SSI) on patients' subjective reactions to a ward soundscape. The study was carried out from July to September 2011 with 31 patients in a cardiothoracic ward. Although strong inferences were not made, it was found that this simple intervention created a 21-26% positive change perception (p<0.05). The paper discusses the results in relation to nursing practice, concluding that SSI could be beneficial in helping patients to feel more comfortable.

  16. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. The tumor ... press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the symptoms ...

  17. Multiscale monitoring of interface failure of brittle coating/ductile substrate systems: A non-destructive evaluation method combined digital image correlation with acoustic emission

    NASA Astrophysics Data System (ADS)

    Mao, W. G.; Wu, D. J.; Yao, W. B.; Zhou, M.; Lu, C.

    2011-10-01

    In this paper, we proposed a non-destructive evaluation method combined digital image correlation with acoustic emission techniques. The method was used to in situ monitor interface failure and internal damage of brittle coating/ductile substrate systems with different size scales. The results show that there is a good relationship between digital image correlation and acoustic emission signals, which can be applied to judge cracking formation and coating delamination and to determine fracture toughness of a thermal barrier coating system subjected to bending.

  18. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  19. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  20. Measurement and evaluation of the acoustic noise of a 3 Tesla MR scanner.

    PubMed

    Hattori, Yoko; Fukatsu, Hiroshi; Ishigaki, Takeo

    2007-01-01

    We measured the sound level and frequencies of the acoustic noise generated by a 3 Tesla (T) MR scanner, and investigated the subjective sound level for 30 healthy volunteers with either earplugs, headphones or both. The sound level of 3T was found to be higher than that of 1.5T in all sequences. The peak sound pressure level of 3T ranged from 125.7 dB for MR angiography to 130.7 dB for single shot EPI on the linear scale. The equivalent noise level was from 110.0 dB for FLAIR to 115.8 dB for T1-IR on the A-weighted scale, which exceeded 99 dB, the level regulated by the International Electrotechnical Commission (IEC). The study of the subjective sound level showed that the effect of noise reduction was not significantly different between earplugs and headphones. However, the use of both devices could reduce the subjective sound level significantly better than either one alone (P < 0.01). Thus we propose wearing both devices for ear-protection during 3T examinations.

  1. Evaluation of MPEG-7-Based Audio Descriptors for Animal Voice Recognition over Wireless Acoustic Sensor Networks

    PubMed Central

    Luque, Joaquín; Larios, Diego F.; Personal, Enrique; Barbancho, Julio; León, Carlos

    2016-01-01

    Environmental audio monitoring is a huge area of interest for biologists all over the world. This is why some audio monitoring system have been proposed in the literature, which can be classified into two different approaches: acquirement and compression of all audio patterns in order to send them as raw data to a main server; or specific recognition systems based on audio patterns. The first approach presents the drawback of a high amount of information to be stored in a main server. Moreover, this information requires a considerable amount of effort to be analyzed. The second approach has the drawback of its lack of scalability when new patterns need to be detected. To overcome these limitations, this paper proposes an environmental Wireless Acoustic Sensor Network architecture focused on use of generic descriptors based on an MPEG-7 standard. These descriptors demonstrate it to be suitable to be used in the recognition of different patterns, allowing a high scalability. The proposed parameters have been tested to recognize different behaviors of two anuran species that live in Spanish natural parks; the Epidalea calamita and the Alytes obstetricans toads, demonstrating to have a high classification performance. PMID:27213375

  2. The nondestructive evaluation of high temperature conditioned concrete in conjunction with acoustic emission and x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Su, Yu-Min; Hou, Tsung-Chin; Lin, Li-Chiang; Chen, Gwan-Ying; Pan, Huang-Hsing

    2016-04-01

    Portland Cement Concrete plays a vital part of protecting structural rebars or steels when high-temperature fire incidents occur, that induces loss of evaporate water, dehydration of CH, and deconstruction of C-S-H. The objective of the study was to assess fire-damaged concrete in conjunction with nondestructive evaluation methods of acoustic emission, visual inspections, and X-ray computed tomography. The experimental program was to mix an Ordinary Portland Cement concrete firstly. Concrete cylinders with twenty-day moisture cure were treated in a furnace with 400 and 600°C for one hour. After temperature is cooled down, the concrete cylinders were brought to air or moisture re-curing for ten days. Due to the incident of the furnace, acoustic emission associated with splitting tensile strength test was not able to continue. Future efforts are planned to resume this unfinished task. However, two proposed tasks were executed and completed, namely visual inspections and voids analysis on segments obtained from X-ray CT facility. Results of visual inspections on cross-sectional and cylindrical length of specimens showed that both aggregates and cement pastes turned to pink or red at 600°C. More surface cracks were generated at 600°C than that at 400°C. On the other hand, voids analysis indicated that not many cracks were generated and voids were remedied at 400°C. However, a clear tendency was found that remedy by moisture curing may heal up to 2% voids of the concrete cylinder that was previously subject to 600°C of high temperature conditioning.

  3. The effect of human-mattress interface's temperature on perceived thermal comfort.

    PubMed

    Califano, R; Naddeo, A; Vink, P

    2017-01-01

    In recent years, methods that allow for an objective evaluation of perceived comfort, in terms of postural, physiological, cognitive and environmental comfort, have received a great deal of attention from researchers. This paper focuses on one of the factors that influences physiological comfort perception: the temperature difference between users and the objects with which they interact. The first aim is to create a measuring system that does not affect the perceived comfort during the temperatures' acquisition. The main aim is to evaluate how the temperature at the human-mattress interface can affect the level of perceived comfort. A foam mattress has been used for testing in order to take into account the entire back part of the human body. The temperature at the interface was registered by fourteen 100 Ohm Platinum RTDs (Resistance Temperature Detectors) placed on the mattress under the trunk, the shoulders, the buttocks, the legs, the thighs, the arms and the forearms of the test subject. 29 subjects participated in a comfort test in a humidity controlled environment. The test protocol involved: dress-code, anthropometric-based positioning on mattress, environment temperature measuring and an acclimatization time before the test. At the end of each test, each of the test subject's thermal sensations and the level of comfort perception were evaluated using the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) scale. The data analyses concerned, in the first instance, correlations between the temperature at the interface and comfort levels of the different parts of the body. Then the same analyses were performed independently of the body parts being considered. The results demonstrated that there was no strong correlation among the studied variables and that the total increase of temperature at interface is associated with a reduction in comfort.

  4. The effect of human-mattress interface's temperature on perceived thermal comfort.

    PubMed

    Califano, R; Naddeo, A; Vink, P

    2017-01-01

    In recent years, methods that allow for an objective evaluation of perceived comfort, in terms of postural, physiological, cognitive and environmental comfort, have received a great deal of attention from researchers. This paper focuses on one of the factors that influences physiological comfort perception: the temperature difference between users and the objects with which they interact. The first aim is to create a measuring system that does not affect the perceived comfort during the temperatures' acquisition. The main aim is to evaluate how the temperature at the human-mattress interface can affect the level of perceived comfort. A foam mattress has been used for testing in order to take into account the entire back part of the human body. The temperature at the interface was registered by fourteen 100 Ohm Platinum RTDs (Resistance Temperature Detectors) placed on the mattress under the trunk, the shoulders, the buttocks, the legs, the thighs, the arms and the forearms of the test subject. 29 subjects participated in a comfort test in a humidity controlled environment. The test protocol involved: dress-code, anthropometric-based positioning on mattress, environment temperature measuring and an acclimatization time before the test. At the end of each test, each of the test subject's thermal sensations and the level of comfort perception were evaluated using the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) scale. The data analyses concerned, in the first instance, correlations between the temperature at the interface and comfort levels of the different parts of the body. Then the same analyses were performed independently of the body parts being considered. The results demonstrated that there was no strong correlation among the studied variables and that the total increase of temperature at interface is associated with a reduction in comfort. PMID:27633230

  5. NREL Provides Guidance to Improve Air Mixing and Thermal Comfort in Homes (Fact Sheet)

    SciTech Connect

    Not Available

    2012-02-01

    NREL research determines optimal HVAC system design for proper air mixing and thermal comfort in homes. As U.S. homes become more energy efficient, heating, ventilation, and cooling (HVAC) systems will be downsized, and the air flow volumes required to meet heating and cooling loads may be too small to maintain uniform room air mixing-which can affect thermal comfort. Researchers at the National Renewable Energy Laboratory (NREL) evaluated the performance of high sidewall air supply inlets and confirmed that these systems can achieve good air mixing and provide suitable comfort levels for occupants. Using computational fluid dynamics modeling, NREL scientists tested the performance of high sidewall supply air jets over a wide range of parameters including supply air temperature, air velocity, and inlet size. This technique uses the model output to determine how well the supply air mixes with the room air. Thermal comfort is evaluated by monitoring air temperature and velocity in more than 600,000 control volumes that make up the occupied zone of a single room. The room has an acceptable comfort level when more than 70% of the control volumes meet the comfort criteria on both air temperature and velocity. The study shows that high sidewall supply air jets achieve uniform mixing in a room, which is essential for providing acceptable comfort levels. The study also provides information required to optimize overall space conditioning system design in both heating and cooling modes.

  6. Evaluation of the Acoustic Measurement Capability of the NASA Langley V/STOL Wind Tunnel Open Test Section with Acoustically Absorbent Ceiling and Floor Treatments

    NASA Technical Reports Server (NTRS)

    Theobald, M. A.

    1978-01-01

    The single source location used for helicopter model studies was utilized in a study to determine the distances and directions upstream of the model accurate at which measurements of the direct acoustic field could be obtained. The method used was to measure the decrease of sound pressure levels with distance from a noise source and thereby determine the Hall radius as a function of frequency and direction. Test arrangements and procedures are described. Graphs show the normalized sound pressure level versus distance curves for the glass fiber floor treatment and for the foam floor treatment.

  7. A conceptual model of intentional comfort touch.

    PubMed

    Connor, Ann; Howett, Maeve

    2009-06-01

    This article discusses the application and integration of intentional comfort touch as a holistic nursing practice. A review of the literature on touch and its related concepts is included. Although nurses use touch frequently in patient encounters, it is not always used intentionally or deliberately to enhance care. The article compares and contrasts intentional comfort touch with nonintentional or procedural touch. The use of intentional comfort touch in innovative clinical settings with diverse and at-risk populations is described. Based on clinical experiences and the current literature, a conceptual model of intentional comfort touch is proposed. The application of touch is discussed as is the meaning and importance of intentional touch for students, faculty, and patients. PMID:19443699

  8. A geological-acoustical framework for an integrated environmental evaluation in Mediterranean marine protected areas. Marettimo Island, a case study

    NASA Astrophysics Data System (ADS)

    Agate, M.; Catalano, R.; Chemello, R.; Lo Iacono, C.; Riggio, S.

    2003-04-01

    A GEOLOGICAL-ACOUSTICAL FRAMEWORK FOR AN INTEGRATED ENVIRONMENTAL EVALUATION IN MEDITERRANEAN MARINE PROTECTED AREAS. MARETTIMO ISLAND, A CASE STUDY. M. Agate (1), R. Catalano (1), R. Chemello (2), C. Lo Iacono (1) &S. Riggio (2) (1)Dipartimento di Geologia e Geodesia dell'Università di Palermo, via Archirafi 26, 90123 Palermo, clageo@katamail.com, rcatal@unipa.it (2)Dipartimento di Biologia animale dell'Università di Palermo, via Archirafi 18, 90123 Palermo,rchemello@unipa.it New analytical methods have been designed to support an objective quantitative evaluation of geological components whose results dictate the lines for a sustainable use of the natural resources. We tried to adopt the fundaments of the seascape concept, based on the thematic elements of landscape ecology and translated into terms fitting with the principles of coastal ecology. The seascape concept is central to our view of the environment and is referred to as an integrated unit (Environmental Unit) resulting from a long multidisciplinary approach, carried out in both the field and the laboratory by an interdisciplinary team of experts. Side Scan Sonar and Multi Beam acoustical data collected in the Marettimo and Ustica Islands (south-western Tyrrhenian Sea))inner shelves, make possible to sketch geomorphological and sedimentological maps, whose details have been tested as deep as 45 m in diving surveys. On the basis of the collected data sets, the inner shelf (0-60 m) has been subdivided into different portions, following the concept of the Environmental Unit (E.U). Every E.U. presents constant morphological and sedimentological features that, probably, can be associated to specified biological communities. In order to find the relationships between physical settings and communities, geological thematic maps are eventually overlaid and fitted to macrobenthic and fishery spatial distribution maps. The result, based on the rule of the Environmental Impact Assessment, puts into evidence the

  9. Human comfort in relation to sinusoidal vibration

    NASA Technical Reports Server (NTRS)

    Jones, B.; Rao, B. K. N.

    1975-01-01

    An investigation was made to assess the overall subjective comfort levels to sinusoidal excitations over the range 1 to 19 Hz using a two axis electrohydraulic vibration simulator. Exposure durations of 16 minutes, 25 minutes, 1 hour, and 2.5 hours have been considered. Subjects were not exposed over such durations, but were instructed to estimate the overall comfort levels preferred had they been constantly subjected to vibration over such durations.

  10. Development and evaluation of an acoustic device to estimate size distribution of channel catfish in commercial ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As one step in the continued effort to utilize acoustic methods and techniques to the betterment of catfish aquaculture, an acoustic “catfish sizer” was designed to determine the size distribution of Channel Catfish Ictalurus punctatus in commercial ponds. The catfish sizer employed a custom-built 4...

  11. Reducing the Impacts of Hydroelectric Dams on Juvenile Anadromous Fishes: Bioengineering Evaluations Using Acoustic Imaging in the Columbia River, USA

    SciTech Connect

    Johnson, Gary E.; Ploskey, Gene R.; Hedgepeth, J.; Khan, Fenton; Mueller, Robert P.; Nagy, William T.; Richmond, Marshall C.; Weiland, Mark A.

    2008-07-29

    Dams impact the survival of juvenile anadromous fishes by obstructing migration corridors, lowering water quality, delaying migrations, and entraining fish in turbine discharge. To reduce these impacts, structural and operational modifications to dams— such as voluntary spill discharge, turbine intake guidance screens, and surface flow outlets—are instituted. Over the last six years, we have used acoustic imaging technology to evaluate the effects of these modifications on fish behavior, passage rates, entrainment zones, and fish/flow relationships at hydroelectric projects on the Columbia River. The imaging technique has evolved from studies documenting simple movement patterns to automated tracking of images to merging and analysis with concurrent hydraulic data. This chapter chronicles this evolution and shows how the information gleaned from the scientific evaluations has been applied to improve passage conditions for juvenile salmonids. We present data from Bonneville and The Dalles dams that document fish behavior and entrainment zones at sluiceway outlets (14 to 142 m3/s), fish passage rates through a gap at a turbine intake screen, and the relationship between fish swimming effort and hydraulic conditions. Dam operators and fisheries managers have applied these data to support decisions on operational and structural changes to the dams for the benefit of anadromous fish populations in the Columbia River basin.

  12. Dynamic thermal environment and thermal comfort.

    PubMed

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research.

  13. Dynamic thermal environment and thermal comfort.

    PubMed

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research. PMID:26171688

  14. Preclinical evaluation of acoustic radiation force impulse measurements in regions of heterogeneous elasticity

    PubMed Central

    Gaßmann, Bernhard; Wagenpfeil, Stefan; Moog, Philipp; Vo-Cong, Minh-Truc; Heemann, Uwe; Stock, Konrad Friedrich

    2016-01-01

    Purpose The purpose of this study was to compare the reliability of ultrasound-based shear wave elastography in regions of homogeneous versus heterogeneous elasticity by using two different probes. Methods Using acoustic radiation force impulse (ARFI) elastography, we measured the shear wave velocity (SWV) in different lesions of an elastography phantom with the convex 4C1 probe and the linear 9L4 probe. The region of interest (ROI) was positioned in such a way that it was partly filled by one of the lesions (0%, 25%, 50%, 75%, and 100%) and partly by the background of the phantom (100%, 75%, 50%, 25%, and 0%, respectively). Results The success rate was 98.5%. The measured value and the reference value of SWV correlated significantly (r=0.89, P<0.001). Further, a comparison of the two probes revealed that there was no statistical difference in either the mean or the variance values. However, the deviation of SWV from the reference was higher in the case of the 9L4 probe than in the case of the 4C1 probe, both overall and in measurements in which the ROI contained structures of different elasticity (P=0.021 and P=0.002). Taking into account all data, for both probes, we found that there was a greater spread and deviation of the SWV from the reference value when the ROI was positioned in structures having different elastic properties (standard deviation, 0.02±0.01 m/sec vs. 0.04±0.04 m/sec; P=0.010; deviation from the reference value, 0.21±0.12 m/sec vs. 0.38±0.27 m/sec; P=0.050). Conclusion Quantitative ARFI elastography was achievable in structures of different elasticity; however, the validity and the reliability of the SWV measurements decreased in comparison to those of the measurements performed in structures of homogeneous elasticity. Therefore, a convex probe is preferred for examining heterogeneous structures. PMID:27599889

  15. [Proposal for recognition of the comfort pattern in clients with pemphigus vulgaris using Fuzzy Logic].

    PubMed

    Brandão, Euzeli da Silva; dos Santos, Iraci; Lanzillotti, Regina Serrão; Moreira, Augusto Júnior

    2013-08-01

    The objective was to propose the use of Fuzzy Logic for recognition of comfort patterns in people undergoing a technology of nursing care because of pemphigus vulgaris, a rare mucocutaneous disease that affects mainly adults. The proposal applied experimental methods, with subjects undergoing a qualitative-quantitative comparison (taxonomy/relevance) of the comfort patterns before and after the intervention. A record of a chromatic scale corresponding to the intensity of each attribute was required: pain, mobility and impaired self-image. The Fuzzy rules established by an inference engine set the standard for comfort in maximum, median and minimum discomfort, reflecting the effectiveness of nursing care. Although rarely used in the area of nursing, this logic enabled viable research without a priori scaling of the number of subjects depending on the estimation of population parameters. It is expected to evaluate the pattern of comfort in the client with pemphigus, before the applied technology, in a personalized way, leading to a comprehensive evaluation.

  16. Cold hands, warm hearth?: Climate, net takeback, household comfort

    SciTech Connect

    Schwarz, P.M.; Taylor, T.N.

    1995-12-31

    Insulation reduces marginal heating costs and may lead to a takeback effect of higher wintertime thermostat settings, with a consequent dilution of energy savings. Alternatively, additional insulation could permit a lower thermostat setting by reducing drafts and radiation while increasing moisture retention, thereby enhancing comfort. This paper evaluates thermostat net takeback, the difference between takeback and enhanced comfort. Evidence supports the existence of both effects, with net takeback at the low end of literature estimates. Net thermostat takeback is on the order of 0.05{degrees}F, leading to an energy takeback that ranges from 1-3% of potential energy savings, depending on climate and house size. Other significant determinants of thermostat are heating energy price and the presence of elderly or young occupants. 19 refs., 4 tabs.

  17. Numerical Analysis of Thermal Comfort at Urban Environment

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, K.; Belias, C.

    2009-08-01

    The present paper refers to the numerical simulation of air velocity at open air spaces and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an open environment area in Athens (athletic park), named "Serafeio Athletic and Cultural Centre," trying to form them in such way that will lead to the thermal comfort of the area's visitors. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This modelling procedure is intended to contribute to the effort towards designing open areas, such as parks, squares or outdoor building environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.

  18. Numerical Analysis of Thermal Comfort at Open Air Spaces

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, K.; Belias, C.; Pantos-Kikkos, S.; Assana, A.

    2008-09-01

    The present paper refers to the numerical simulation of air velocity at open air spaces and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an open environment area in Athens (urban park), named "Attiko Alsos," trying to form them in such way that will lead to the thermal comfort of the area's visitors. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This modelling procedure is intended to contribute to the effort towards designing open areas, such as parks, squares or outdoor building environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.

  19. Comparison of subjective comfort ratings between anatomically shaped and cylindrical handles.

    PubMed

    Harih, Gregor; Dolšak, Bojan

    2014-07-01

    Most authors have provided diameter recommendations for cylindrical handle design in order to increase performance, avoid discomfort, and reduce the risk of cumulative trauma disorders. None of the studies has investigated the importance of determining the correct handle shape on the subjective comfort ratings, which could further improve the handles' ergonomics. Therefore, new methods based on a virtual hand model in its optimal power grasp posture have been developed in order to obtain customised handles with best fits for targeted subjects. Cylindrical and anatomically shaped handles were evaluated covering ten subjects by means of an extensive subjective comfort questionnaire. The results suggest large impact of the handle shape on the perceived subjective comfort ratings. Anatomically shaped handles were rated as being considerably more comfortable than cylindrical handles for almost all the subjective comfort predictors. They showed that handle shapes based on optimal power grasp postures can improve subjective comfort ratings, thus maximising performance. Future research should consider real conditions, since the comfort ratings can vary based on the specific task and by the tool selected for the task.

  20. Using Hand Grip Force as a Correlate of Longitudinal Acceleration Comfort for Rapid Transit Trains.

    PubMed

    Guo, Beiyuan; Gan, Weide; Fang, Weining

    2015-07-02

    Longitudinal acceleration comfort is one of the essential metrics used to evaluate the ride comfort of train. The aim of this study was to investigate the effectiveness of using hand grip force as a correlate of longitudinal acceleration comfort of rapid transit trains. In the paper, a motion simulation system was set up and a two-stage experiment was designed to investigate the role of the grip force on the longitudinal comfort of rapid transit trains. The results of the experiment show that the incremental grip force was linearly correlated with the longitudinal acceleration value, while the incremental grip force had no correlation with the direction of the longitudinal acceleration vector. The results also show that the effects of incremental grip force and acceleration duration on the longitudinal comfort of rapid transit trains were significant. Based on multiple regression analysis, a step function model was established to predict the longitudinal comfort of rapid transit trains using the incremental grip force and the acceleration duration. The feasibility and practicably of the model was verified by a field test. Furthermore, a comparative analysis shows that the motion simulation system and the grip force based model were valid to support the laboratory studies on the longitudinal comfort of rapid transit trains.

  1. Using Hand Grip Force as a Correlate of Longitudinal Acceleration Comfort for Rapid Transit Trains

    PubMed Central

    Guo, Beiyuan; Gan, Weide; Fang, Weining

    2015-01-01

    Longitudinal acceleration comfort is one of the essential metrics used to evaluate the ride comfort of train. The aim of this study was to investigate the effectiveness of using hand grip force as a correlate of longitudinal acceleration comfort of rapid transit trains. In the paper, a motion simulation system was set up and a two-stage experiment was designed to investigate the role of the grip force on the longitudinal comfort of rapid transit trains. The results of the experiment show that the incremental grip force was linearly correlated with the longitudinal acceleration value, while the incremental grip force had no correlation with the direction of the longitudinal acceleration vector. The results also show that the effects of incremental grip force and acceleration duration on the longitudinal comfort of rapid transit trains were significant. Based on multiple regression analysis, a step function model was established to predict the longitudinal comfort of rapid transit trains using the incremental grip force and the acceleration duration. The feasibility and practicably of the model was verified by a field test. Furthermore, a comparative analysis shows that the motion simulation system and the grip force based model were valid to support the laboratory studies on the longitudinal comfort of rapid transit trains. PMID:26147730

  2. Interracial Social Comfort and Its Relationship to Adjustment to College

    ERIC Educational Resources Information Center

    McDonald, Scott D.; Vrana, Scott R.

    2007-01-01

    The present study examined the effects of interracial social comfort on college adjustment for 45 Black and 82 White students at a predominantly-White university. Black students reporting more comfort with Whites, regardless of level of comfort with Blacks, experienced better college adjustment. Furthermore, more social comfort with Blacks…

  3. Topological Acoustics

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-01

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  4. Topological acoustics.

    PubMed

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-20

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  5. Compact test method for the evaluation of acoustical transmission loss and insertion loss of new helmet material samples

    NASA Astrophysics Data System (ADS)

    Maher, Matthew G.; Collier, Robert D.; Ray, Laura E.

    2005-09-01

    There is a need to establish a simple and accurate measurement technique for determining the transmission loss of sample materials for helmets over a frequency range of 300-3 kHz. Standard methods, e.g., ASTM E 90-02, for measuring transmission loss of building materials and structures, based on adjacent reverberation chambers, are too costly and impractical. A 1.22-m-long double-wall tube, packed with Owens Corning R13 insulation, has been fabricated using QUIK-TUBETM cardboard concrete forms of 200 and 300 mm diameters. A circular sample of material, also 300 mm in diameter, is placed on the end of the tube and subjected to an external sound field. Transmission loss is established by external and internal microphones. This paper describes the measurement and analysis procedures and examines the associated variables and error terms. Results are presented for 16 material samples with surface weights covering a range from 0.3 to 14.7 kg/m2 and compared with analytical predictions including mass law models. The acoustical characteristics of commercial helmet materials and liners are evaluated in the context of hearing protection systems. The transmission loss measurement procedure has the potential for meeting standardization objectives.

  6. Evaluation of the Temporal Acoustic Window for Transcranial Doppler in a Multi-Ethnic Population in Brazil.

    PubMed

    Bazan, Rodrigo; Braga, Gabriel Pereira; Luvizutto, Gustavo José; Hueb, João Carlos; Hokama, Newton Key; Zanati Bazan, Silméia Garcia; de Carvalho Nunes, Hélio Rubens; Leite, João Pereira; Pontes-Neto, Octávio Marques

    2015-08-01

    The aim of this study was to relate the presence of a temporal acoustic window (TAW) to the variables sex, age and race. This observational study was conducted in patients under etiologic investigation after stroke, sickle-cell anemia and hospitalization in an intensive therapy neurologic unit. TAW presence was confirmed by bilateral assessment by two neurologists via transcranial Doppler (TCD). Multiple logistic regression was performed to explain the presence of the window as a function of sex, age and race. In 20% of the 262 patients evaluated, a TAW was not present. The incidence of TAW presence was greater in men (odds ratio [OR] = 5.4, 95% confidence interval [CI] = 2.5-11.7, p < 0.01); lower with increased age (OR = 0.9, 95% CI = 0.92-0.97, p < 0.01); and lower among those of African and Asian descent (OR = 0.32, 95% CI = 0.14-0.70, p = 0.005). On the basis of the results, more men than women had TAWs, and the decrease in TAWs was associated with increased age and African or Asian descent.

  7. Evaluation of the Acoustic Doppler Velocity Meter for Computation of Discharge Records at Three Sites in Colorado, 2004-2005

    USGS Publications Warehouse

    Stevens, Michael R.; Diaz, Paul; Smits, Dennis E.

    2008-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board, conducted a study in 2004-2005 at three sites in Colorado: Bear Creek at Morrison, Clear Creek near Empire, and Redlands Canal near Grand Junction. The study was done to evaluate acoustic Doppler velocity meter (ADVM) technology in different hydrologic settings that are characteristic of many Colorado streamflow-gaging sites. ADVMs have been tested and used extensively in many parts of the United States by USGS but not in Colorado where relatively small, shallow, clear, coarse-bed streams that ice up in the winter may affect the ADVM suitability. In this study, ADVM instrumentation was successfully used and discharge computations compared favorably, generally within 5 to 10 percent, with conventional USGS stage/discharge methods at the three Colorado sites. However, two factors, encountered in this study, may adversely affect the use of ADVM technology in Colorado. First, for some streams, the depth required (about 1.5 feet for a side-looking instrument) cannot be met during low-flow periods of the year. Second, cold temperatures and freezing-thawing cycles can produce ice effects that could prevent collection of usable ADVM (and stage) data.

  8. Comfort Theory and its application to pediatric nursing.

    PubMed

    Kolcaba, Katharine; DiMarco, Marguerite A

    2005-01-01

    Although written protocols currently are directed more to pain relief than to the comfort of each child, there is increasing interest in pediatric literature about comforting strategies for children and their families. However, pediatric nurses/researchers currently utilize measures of discomfort that designate a neutral sense of comfort as in the absence of a specific discomfort. Assessing comfort as a positive, holistic outcome is important for measuring effectiveness of comforting strategies. Comfort Theory (Kolcaba, 2003), with its inherent emphasis on physical, psychospiritual, sociocultural, and environmental aspects of comfort, will contribute to a proactive and multifaceted approach to care. The framework of Comfort Theory for pediatric practice and research is easy to understand and implement. The application of the theory is strengthening and satisfying for pediatric patients/families and nurses, and benefits institutions where a culture of comfort is valued. Moreover, comfort is a transcultural and interdisciplinary concern.

  9. Entropy generation method to quantify thermal comfort

    NASA Technical Reports Server (NTRS)

    Boregowda, S. C.; Tiwari, S. N.; Chaturvedi, S. K.

    2001-01-01

    The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study

  10. Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2011

    SciTech Connect

    Weiland, Mark A.; Woodley, Christa M.; Ploskey, Gene R.; Hughes, James S.; Hennen, Matthew J.; Kim, Jin A.; Deng, Zhiqun; Fu, Tao; Skalski, J. R.; Townsend, Richard L.; Wagner, Katie A.; Fischer, Eric S.; Duncan, Joanne P.; Batten, G.; Carlson, Thomas J.; Carpenter, Scott M.; Cushing, Aaron W.; Elder, T.; Etherington, D. J.; Johnson, Gary E.; Khan, Fenton; Miracle, Ann L.; Mitchell, T. D.; Prather, K.; Rayamajhi, Bishes; Royer, Ida; Seaburg, Adam; Zimmerman, Shon A.

    2013-06-21

    This report presents survival, behavioral, and fish passage results for tagged yearling Chinook salmon and juvenile steelhead as part of a survival study conducted at John Day Dam during spring 2011. This study was designed to evaluate the passage and survival of yearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a paired-release survival model.

  11. Vibro-acoustic analysis of composite plates

    NASA Astrophysics Data System (ADS)

    Sarigül, A. S.; Karagözlü, E.

    2014-03-01

    Vibro-acoustic analysis plays a vital role on the design of aircrafts, spacecrafts, land vehicles and ships produced from thin plates backed by closed cavities, with regard to human health and living comfort. For this type of structures, it is required a coupled solution that takes into account structural-acoustic interaction which is crucial for sensitive solutions. In this study, coupled vibro-acoustic analyses of plates produced from composite materials have been performed by using finite element analysis software. The study has been carried out for E-glass/Epoxy, Kevlar/Epoxy and Carbon/Epoxy plates with different ply angles and numbers of ply. The effects of composite material, ply orientation and number of layer on coupled vibro-acoustic characteristics of plates have been analysed for various combinations. The analysis results have been statistically examined and assessed.

  12. Effects of exposure time during flight maneuvers on passenger subjective comfort rating

    NASA Technical Reports Server (NTRS)

    Brown, V. J.

    1975-01-01

    The effects were investigated of length of exposure time to a flight maneuver environment on subjective passenger evaluation of ride comfort. Four statistical analysis tests were performed on ride comfort ratings obtained during one two-hour test flight wherein eleven test subjects were exposed to two identical programmed sequences of twenty four flight segments which covered a wide range of maneuver conditions. The results of the analysis indicate that, for over ninety five percent of the segments, there is no significant change in the test subjects comfort ratings of identical segments spaced one hour apart. These results are in contrast to those found in previous studies involving a vibration environment, rather than flight maneuver environment, where increased exposure-time was found to cause a degradation of ride comfort ratings.

  13. Evaporative cooling: Thermal comfort and its energy implications in California climates

    NASA Astrophysics Data System (ADS)

    Xu, Tengfang

    1998-09-01

    acceptable temperatures than specified in ASHRAE Standard 55's comfort zone. Controllable air movement is beneficial for thermal comfort in these buildings. The simulations predict indoor conditions and energy use in selected climates for evaluating energy savings' against conventional systems. The results suggest that evaporative cooling can be a feasible alternative cooling technology in California, from the standpoint of thermal comfort and energy efficiency.

  14. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  15. Quantitative broadband ultrasonic backscatter - An approach to nondestructive evaluation in acoustically inhomogeneous materials

    NASA Technical Reports Server (NTRS)

    Odonnell, M.; Miller, J. G.

    1981-01-01

    The use of a broadband backscatter technique to obtain the frequency dependence of the longitudinal-wave ultrasonic backscatter coefficient from a collection of scatterers in a solid is investigated. Measurements of the backscatter coefficient were obtained over the range of ultrasonic wave vector magnitude-glass sphere radius product between 0.1 and 3.0 from model systems consisting of dilute suspensions of randomly distributed crown glass spheres in hardened polyester resin. The results of these measurements were in good agreement with theoretical prediction. Consequently, broadband measurements of the ultrasonic backscatter coefficient may represent a useful approach toward characterizing the physical properties of scatterers in intrinsically inhomogeneous materials such as composites, metals, and ceramics, and may represent an approach toward nondestructive evaluation of these materials.

  16. Adaptive structural vibration control of acoustic deflector

    NASA Astrophysics Data System (ADS)

    Ostasevicius, Vytautas; Palevicius, Arvydas; Ragulskis, Minvydas; Dagys, Donatas; Janusas, Giedrius

    2004-06-01

    Vehicle interior acoustics became an important design criterion. Both legal restrictions and the growing demand for comfort, force car manufacturers to optimize the vibro-acoustic behavior of their products. The main source of noise is, of course, the engine, but sometimes some ill-designed cover or other shell structure inside the car resonates and makes unpredicted noise. To avoid this, we must learn the genesis mechanism of such vibrations, having as subject complex 3D shells. The swift development of computer technologies opens the possibility to numerically predict and optimize the vibrations and noises.

  17. Achieving success: moving beyond the comfort level.

    PubMed

    Manji, I

    1993-11-01

    Understanding the stages of growth, saturation and transition is the first step to setting meaningful career goals. While this concept is fairly new in dentistry, it is not new in other commercial enterprises. Business managers and owners have known for decades that growth stagnates after a period of time. At that point, a new infusion of energy and a reformation of the business's objectives and methods are needed to launch forward into the next phase of growth. Transition management in dentistry represents periods of growth that are followed by saturation and a comparatively rapid changeover to a new practice form. Saturation occurs when the clinical capacity of a practice is exceeded by the needs of a growing patient base. The key transitions in the career of a dentist are those from school to practising, and practising to retirement. A great number of dentists (due to low motivation, the comfort level or poor management skills) never reach the saturation point during their practising career. For these dentists, starting out and retirement are the only transitions that will ever apply to them. Dentists evaluating transition options must first identify which career stage they belong to since their objectives will be different at each stage. Dentists in the growth phase should focus on practice management and achieving saturation before attempting a transition. Since transitions like start-up, retirement, partnerships, associateships and buy-ins have pivotal roles in the life cycle of a practice, transitions must be managed carefully to achieve successful results.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Acoustic metafluids.

    PubMed

    Norris, Andrew N

    2009-02-01

    Acoustic metafluids are defined as the class of fluids that allow one domain of fluid to acoustically mimic another, as exemplified by acoustic cloaks. It is shown that the most general class of acoustic metafluids are materials with anisotropic inertia and the elastic properties of what are known as pentamode materials. The derivation uses the notion of finite deformation to define the transformation of one region to another. The main result is found by considering energy density in the original and transformed regions. Properties of acoustic metafluids are discussed, and general conditions are found which ensure that the mapped fluid has isotropic inertia, which potentially opens up the possibility of achieving broadband cloaking. PMID:19206861

  19. Evaluating Directional Resolution of Aplanatic Acoustic Lens for Designing Ambient Noise Imaging System

    NASA Astrophysics Data System (ADS)

    Mori, Kazuyoshi; Ogasawara, Hanako; Nakamura, Toshiaki; Sato, Yuji; Tsuchiya, Takenobu; Endoh, Nobuyuki

    2009-07-01

    In our previous studies, it was verified that a spherical biconcave lens with an aperture diameter of 2.0 m has a sufficient directional resolution (e.g., a beam width of 1° at 60 kHz) for realizing an ambient noise imaging (ANI) system. In this study, an aplanatic lens that corrects both spherical and coma aberrations with the same aperture was designed for an ANI system, and its directional resolution was evaluated. First, in order to predict the resolution, we performed a numerical analysis using the finite difference time domain (FDTD) method. Second, the numerical analysis results were verified by a small-scale trial of one-fifth of full size in a water tank. The shapes of the -3 dB areas were similar between the numerical analysis and experimental results at small incidence angles, and the -3 dB areas do not overlap at 1° increments of incidence angle. The resolution of the aplanatic lens was closer to that of an ideal lens than to that of the spherical lens. Finally, it was satisfied that the present lens has sufficient directional resolution for use in an ANI system.

  20. Evaluation of a scale-model experiment to investigate long-range acoustic propagation

    NASA Technical Reports Server (NTRS)

    Parrott, Tony L.; Mcaninch, Gerry L.; Carlberg, Ingrid A.

    1987-01-01

    Tests were conducted to evaluate the feasibility of using a scale-model experiment situated in an anechoic facility to investigate long-range sound propagation over ground terrain. For a nominal scale factor of 100:1, attenuations along a linear array of six microphones colinear with a continuous-wave type of sound source were measured over a wavelength range from 10 to 160 for a nominal test frequency of 10 kHz. Most tests were made for a hard model surface (plywood), but limited tests were also made for a soft model surface (plywood with felt). For grazing-incidence propagation over the hard surface, measured and predicted attenuation trends were consistent for microphone locations out to between 40 and 80 wavelengths. Beyond 80 wavelengths, significant variability was observed that was caused by disturbances in the propagation medium. Also, there was evidence of extraneous propagation-path contributions to data irregularities at more remote microphones. Sensitivity studies for the hard-surface and microphone indicated a 2.5 dB change in the relative excess attenuation for a systematic error in source and microphone elevations on the order of 1 mm. For the soft-surface model, no comparable sensitivity was found.

  1. Intracardiac Acoustic Radiation Force Impulse Imaging: A Novel Imaging Method for Intraprocedural Evaluation of Radiofrequency Ablation Lesions

    PubMed Central

    Eyerly, Stephanie A.; Bahnson, Tristram D.; Koontz, Jason I.; Bradway, David P.; Dumont, Douglas M.; Trahey, Gregg E.; Wolf, Patrick D.

    2012-01-01

    Background Arrhythmia recurrence after cardiac radiofrequency ablation (RFA) for atrial fibrillation (AF) has been linked to conduction through discontinuous lesion lines. Intraprocedural visualization and corrective ablation of lesion line discontinuities could decrease post-procedure AF recurrence. Intracardiac acoustic radiation force impulse (ARFI) imaging is a new imaging technique that visualizes RFA lesions by mapping the relative elasticity contrast between compliant-unablated and stiff-RFA treated myocardium. Objective To determine if intraprocedure ARFI images can identify RFA treated myocardium in vivo. Methods In eight canines, an electroanatomical mapping (EAM) guided intracardiac echo catheter (ICE) was used to acquire 2D ARFI images along right atrial ablation lines before and after RFA. ARFI images were acquired during diastole with the myocardium positioned at the ARFI focus (1.5 cm) and parallel to the ICE transducer for maximal and uniform energy delivery to the tissue. Three reviewers categorized each ARFI image as depicting no lesion, non-contiguous, or contiguous lesion. For comparison, three separate reviewers confirmed RFA lesion presence and contiguity based on functional conduction block at the imaging plane location on EAM activation maps. Results Ten percent of ARFI images were discarded due to motion artifacts. Reviewers of the ARFI images detected RFA-treated sites with high sensitivity (95.7%) and specificity (91.5%). Reviewer identification of contiguous lesion had 75.3% specificity and 47.1% sensitivity. Conclusions Intracardiac ARFI imaging was successful in identifying endocardial RFA treatment when specific imaging conditions were maintained. Further advances in ARFI imaging technology would facilitate a wider range of imaging opportunities for clinical lesion evaluation. PMID:22772134

  2. Evaluation of the effects of botulinum toxin A injections when used to improve ease of care and comfort in children with cerebral palsy whom are non-ambulant: a double blind randomized controlled trial

    PubMed Central

    2012-01-01

    Background Children with cerebral palsy (CP) whom are non-ambulant are at risk of reduced quality of life and poor health status. Severe spasticity leads to discomfort and pain. Carer burden for families is significant. This study aims to determine whether intramuscular injections of botulinum toxin A (BoNT-A) combined with a regime of standard therapy has a positive effect on care and comfort for children with CP whom are non-ambulant (GMFCS IV/V), compared with standard therapy alone (cycle I), and whether repeated injections with the same regime of adjunctive therapy results in greater benefits compared with a single injecting episode (cycle II). The regime of therapy will include serial casting, splinting and/or provision of orthoses, as indicated, combined with four sessions of goal directed occupational therapy or physiotherapy. Method/design This study is a double blind randomized controlled trial. Forty participants will be recruited. In cycle I, participants will be randomized to either a treatment group who will receive BoNT-A injections into selected upper and/or lower limb muscles, or a control group who will undergo sham injections. Both groups will receive occupational therapy and /or physiotherapy following injections. Groups will be assessed at baseline then compared at 4 and 16 weeks following injections or sham control. Parents, treating clinicians and assessors will be masked to group allocation. In cycle II, all participants will undergo intramuscular BoNT-A injections to selected upper and/or lower limb muscles, followed by therapy. The primary outcome measure will be change in parent ratings in identified areas of concern for their child’s care and comfort, using the Canadian Occupational Performance Measure (COPM). Secondary measures will include the Care and Comfort Hypertonicity Scale (ease of care), the Cerebral Palsy Quality of Life Questionnaire (CP QoL–Child) (quality of life), the Caregiver Priorities and Child Health Index of Life

  3. Infants and Toddlers: Soothing and Comforting Babies

    ERIC Educational Resources Information Center

    Honig, Alice Sterling

    2004-01-01

    Babies thrive on security. In early months, secure feelings stem from being warm, cuddled closely, and comfortable in their tummies (and in having clean bottoms!). In this article, the author discusses how to soothe infants and toddlers. The strategies to help ease babies' distress are described. Some of the recommended strategies include: (1) to…

  4. Transmission in nonuniform ducts - A comparative evaluation of finite element and weighted residuals computational schemes. [acoustic propagation

    NASA Technical Reports Server (NTRS)

    Eversman, W.; Astley, R. J.; Thanh, V. P.

    1977-01-01

    The Method of Weighted Residuals (MWR) and the Finite Element Method (FEM) are considered as computational schemes in the problem of acoustic transmission in nonuniform ducts. MWR is presented in an improved form which includes the interaction of acoustic modes (irrotational) and hydrodynamic modes (rotational). FEM is based on a weighted residuals formulation using eight noded isoparametric elements. Both are applicable to two-dimensional and axially symmetric problems. Calculations are made for several sample problems to demonstrate accuracy and relative efficiency. One test case has implications in the phenomenon of subsonic acoustic choking and it is found that a large transmission loss is not an automatic consequence of propagation against a high subsonic mean flow.

  5. Are pressure measurements effective in the assessment of office chair comfort/discomfort? A review.

    PubMed

    Zemp, Roland; Taylor, William R; Lorenzetti, Silvio

    2015-05-01

    Nowadays, the majority of jobs in the western world involves sitting in an office chair. As a result, a comfortable and supported sitting position is essential for employees. In the literature, various objective methods (e.g. pressure measurements, measurements of posture, EMG etc.) have been used to assess sitting comfort/discomfort, but their validity remains unknown. This review therefore examines the relationship between subjective comfort/discomfort and pressure measurements while sitting in office chairs. The literature search resulted in eight papers that met all our requirements. Four studies identified a relationship between subjective comfort/discomfort and pressure distribution parameters (including correlations of up to r = 0.7 ± 0.13). However, the technique for evaluating subjective comfort/discomfort seems to play an important role on the results achieved, therefore placing their validity into question. The peak pressure on the seat pan, the pressure distribution on the backrest and the pressure pattern changes (seat pan and backrest) all appear to be reliable measures for quantifying comfort or discomfort.

  6. Evaluation of acoustic doppler velocity meters to quantify flow from Comal Springs and San Marcos Springs, Texas

    USGS Publications Warehouse

    Gary, Marcus O.; Gary, Robin H.; Asquith, William H.

    2008-01-01

    Comal Springs and San Marcos Springs are the two largest springs in Texas, are major discharge points for the San Antonio segment of the Edwards aquifer, and provide habitat for several Federally listed endangered species that depend on adequate springflows for survival. It is therefore imperative that the Edwards Aquifer Authority have accurate and timely springflow data to guide resource management. Discharge points for Comal Springs and San Marcos Springs are submerged in Landa Lake and in Spring Lake, respectively. Flows from the springs currently (2008) are estimated by the U.S Geological Survey in real time as surface-water discharge from conventional stage-discharge ratings at sites downstream from each spring. Recent technological advances and availability of acoustic Doppler velocity meters (ADVMs) now provide tools to collect data (stream velocity) related to springflow that could increase accuracy of real-time estimates of the springflows. The U.S. Geological Survey, in cooperation with the Edwards Aquifer Authority, did a study during May 2006 through September 2007 to evaluate ADVMs to quantify flow from Comal and San Marcos Springs. The evaluation was based on two monitoring approaches: (1) placement of ADVMs in important spring orifices - spring run 3 and spring 7 at Comal Springs, and diversion spring at San Marcos Springs; and (2) placement of ADVMs at the nearest flowing streams - Comal River new and old channels for Comal Springs, Spring Lake west and east outflow channels and current (2008) San Marcos River streamflow-gaging site for San Marcos Springs. For Comal Springs, ADVM application at spring run 3 and spring 7 was intended to indicate whether the flows of spring run 3 and spring 7 can be related to total springflow. The findings indicate that velocity data from both discharge features, while reflecting changes in flow, do not reliably show a direct relation to measured streamflow and thus to total Comal Springs flow. ADVMs at the Comal

  7. Acoustic trauma

    MedlinePlus

    Acoustic trauma is a common cause of sensory hearing loss . Damage to the hearing mechanisms within the inner ... Symptoms include: Partial hearing loss that most often involves ... The hearing loss may slowly get worse. Noises, ringing in ...

  8. Acoustic Neuroma

    MedlinePlus

    ... slow growing tumor which arise primarily from the vestibular portion of the VIII cranial nerve and lie ... you have a "brain tumor" called acoustic neuroma (vestibular schwannoma). You think you are the only one ...

  9. Underwater Acoustics.

    ERIC Educational Resources Information Center

    Creasey, D. J.

    1981-01-01

    Summarizes the history of underwater acoustics and describes related research studies and teaching activities at the University of Birmingham (England). Also includes research studies on transducer design and mathematical techniques. (SK)

  10. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  11. Quantitative evaluation of residual torque of a loose bolt based on wave energy dissipation and vibro-acoustic modulation: A comparative study

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Liu, Menglong; Su, Zhongqing; Xiao, Yi

    2016-11-01

    A wave energy dissipation (WED)-based linear acoustic approach and a vibro-acoustic modulation (VM)-based nonlinear method were developed comparatively, for detecting bolt loosening in bolted joints and subsequently evaluating the residual torque of the loose bolt. For WED-based, an analytical model residing on the Hertzian contact theory was established, whereby WED was linked to the residual torque of a loose bolt, contributing to a linear index. For VM-based, contact acoustic nonlinearity (CAN) engendered at the joining interface, when a pumping vibration perturbs a probing wave, was interrogated, and the nonlinear contact stiffness was described in terms of a Taylor series, on which basis a nonlinear index was constructed to associate spectral features with the residual torque. Based respectively on a linear and a nonlinear premise, the two indices were validated experimentally, and the results well coincided with theoretical predication. Quantitative comparison of the two indices surmises that the VM-based nonlinear method outperforms the WED-based linear approach in terms of sensitivity and accuracy, and particularly when the bolt loosening is in its embryo stage. In addition, the detectability of the nonlinear index is not restricted by the type of the joint, against a high dependence of its linear counterpart on the joint type.

  12. Validation and Simulation of Ares I Scale Model Acoustic Test - 3 - Modeling and Evaluating the Effect of Rainbird Water Deluge Inclusion

    NASA Technical Reports Server (NTRS)

    Strutzenberg, Louise L.; Putman, Gabriel C.

    2011-01-01

    The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. Building on dry simulations of the ASMAT tests with the vehicle at 5 ft. elevation (100 ft. real vehicle elevation), wet simulations of the ASMAT test setup have been performed using the Loci/CHEM computational fluid dynamics software to explore the effect of rainbird water suppression inclusion on the launch platform deck. Two-phase water simulation has been performed using an energy and mass coupled lagrangian particle system module where liquid phase emissions are segregated into clouds of virtual particles and gas phase mass transfer is accomplished through simple Weber number controlled breakup and boiling models. Comparisons have been performed to the dry 5 ft. elevation cases, using configurations with and without launch mounts. These cases have been used to explore the interaction between rainbird spray patterns and launch mount geometry and evaluate the acoustic sound pressure level knockdown achieved through above-deck rainbird deluge inclusion. This comparison has been anchored with validation from live-fire test data which showed a reduction in rainbird effectiveness with the presence of a launch mount.

  13. Measured Cooling Season Results Relating the Impact of Mechanical Ventilation on Energy, Comfort, and Indoor Air Quality in Humid Climates

    SciTech Connect

    Martin, Eric; Amos, Bryan; McIlvaine, Janet; Chasar, David; Widder, Sarah H.; Fonorow, Ken

    2014-08-22

    Conference Paper for ACEEE Summer Study in Buildings discussing results to date of a project evaluating the impact of ventialtion on energy use, comfort, durability, and cost in the hot humid climate.

  14. On the evaluation of effective density for plate- and membrane-type acoustic metamaterials without mass attached.

    PubMed

    Huang, Tai-Yun; Shen, Chen; Jing, Yun

    2016-08-01

    The effective densities of plate- and membrane-type acoustic metamaterials (AMMs) without mass attached are studied theoretically and numerically. Three models, including the analytic model (based on the plate flexural wave equation and the membrane wave equation), approximate model (under the low frequency approximation), and the finite element method (FEM) model, are first used to calculate the acoustic impedance of square and clamped plates or membranes. The effective density is then obtained using the resulting acoustic impedance and a lumped model. Pressure transmission coefficients of the AMMs are computed using the obtained densities. The effect of the loss from the plate is also taken into account. Results from different models are compared and good agreement is found, particularly between the analytic model and the FEM model. The approximate model is less accurate when the frequency of interest is above the first resonance frequency of the plate or membrane. The approximate model, however, provides simple formulae to predict the effective densities of plate- or membrane-type AMMs and is accurate for the negative density frequency region. The methods presented in this paper are useful in designing AMMs for manipulating acoustic waves. PMID:27586723

  15. Acoustic Analysis of Composite Soft Materials IV.Evaluation of Compressibility of Bound Rubber in Carbon Black Filled SBR

    NASA Astrophysics Data System (ADS)

    Maebayashi, Masahiro; Endo, Masashi; Matsuoka, Tatsuro; Koda, Shinobu; Isono, Yoshinobu

    A carbon black (CB) filled styrene-butadiene rubber (SBR) compound was investigated by acoustic techniques, scanning acoustic microscopy and longitudinal wave velocitometry. The CB agglomerates of larger than 5 µm dispersed in the compound mixed by two-roll mill were observed as black spots in acoustic micrographs. On the other hand, the CB agglomerates in the compound mixed by oil-pressure kneader were not observed in the acoustic micrograph, since the particle size of the agglomerates was less than 5 µm. The density and the longitudinal wave velocity of the compound were measured as a function of the weight percentage of the CB. The density and the velocity increased linearly with the content of the CB. The mass ratio of the bound rubber to the CB in the unvulcanized sample was determined by using toluene extraction and thermo gravimetric analysis. The partial specific adiabatic compressibility of the CB was estimated as (-0.5±0.5)×10-10 Pa-1 on the basis of the three states model. The adiabatic compressibility of the bound rubber was (2.2±0.5)×10-10 Pa-1, and it is half of that of the SBR matrix.

  16. On the evaluation of effective density for plate- and membrane-type acoustic metamaterials without mass attached.

    PubMed

    Huang, Tai-Yun; Shen, Chen; Jing, Yun

    2016-08-01

    The effective densities of plate- and membrane-type acoustic metamaterials (AMMs) without mass attached are studied theoretically and numerically. Three models, including the analytic model (based on the plate flexural wave equation and the membrane wave equation), approximate model (under the low frequency approximation), and the finite element method (FEM) model, are first used to calculate the acoustic impedance of square and clamped plates or membranes. The effective density is then obtained using the resulting acoustic impedance and a lumped model. Pressure transmission coefficients of the AMMs are computed using the obtained densities. The effect of the loss from the plate is also taken into account. Results from different models are compared and good agreement is found, particularly between the analytic model and the FEM model. The approximate model is less accurate when the frequency of interest is above the first resonance frequency of the plate or membrane. The approximate model, however, provides simple formulae to predict the effective densities of plate- or membrane-type AMMs and is accurate for the negative density frequency region. The methods presented in this paper are useful in designing AMMs for manipulating acoustic waves.

  17. Comfort, Indoor Air Quality, and Energy Consumption in Low Energy Homes

    SciTech Connect

    Engelmann, P.; Roth, K.; Tiefenbeck, V.

    2013-01-01

    This report documents the results of an in-depth evaluation of energy consumption and thermal comfort for two potential net zero-energy homes (NZEHs) in Massachusetts, as well as an indoor air quality (IAQ) evaluation performed in conjunction with Lawrence Berkeley National Laboratory (LBNL).

  18. Evaluating the intensity of the acoustic radiation force impulse (ARFI) in intravascular ultrasound (IVUS) imaging: Preliminary in vitro results.

    PubMed

    Shih, Cho-Chiang; Lai, Ting-Yu; Huang, Chih-Chung

    2016-08-01

    The ability to measure the elastic properties of plaques and vessels is significant in clinical diagnosis, particularly for detecting a vulnerable plaque. A novel concept of combining intravascular ultrasound (IVUS) imaging and acoustic radiation force impulse (ARFI) imaging has recently been proposed. This method has potential in elastography for distinguishing between the stiffness of plaques and arterial vessel walls. However, the intensity of the acoustic radiation force requires calibration as a standard for the further development of an ARFI-IVUS imaging device that could be used in clinical applications. In this study, a dual-frequency transducer with 11MHz and 48MHz was used to measure the association between the biological tissue displacement and the applied acoustic radiation force. The output intensity of the acoustic radiation force generated by the pushing element ranged from 1.8 to 57.9mW/cm(2), as measured using a calibrated hydrophone. The results reveal that all of the acoustic intensities produced by the transducer in the experiments were within the limits specified by FDA regulations and could still displace the biological tissues. Furthermore, blood clots with different hematocrits, which have elastic properties similar to the lipid pool of plaques, with stiffness ranging from 0.5 to 1.9kPa could be displaced from 1 to 4μm, whereas the porcine arteries with stiffness ranging from 120 to 291kPa were displaced from 0.4 to 1.3μm when an acoustic intensity of 57.9mW/cm(2) was used. The in vitro ARFI images of the artery with a blood clot and artificial arteriosclerosis showed a clear distinction of the stiffness distributions of the vessel wall. All the results reveal that ARFI-IVUS imaging has the potential to distinguish the elastic properties of plaques and vessels. Moreover, the acoustic intensity used in ARFI imaging has been experimentally quantified. Although the size of this two-element transducer is unsuitable for IVUS imaging, the

  19. An evaluation of fish behavior upstream of the water temperature control tower at Cougar Dam, Oregon, using acoustic cameras, 2013

    USGS Publications Warehouse

    Adams, Noah S.; Smith, Collin; Plumb, John M.; Hansen, Gabriel S.; Beeman, John W.

    2015-07-06

    This report describes the initial year of a 2-year study to determine the feasibility of using acoustic cameras to monitor fish movements to help inform decisions about fish passage at Cougar Dam near Springfield, Oregon. Specifically, we used acoustic cameras to measure fish presence, travel speed, and direction adjacent to the water temperature control tower in the forebay of Cougar Dam during the spring (May, June, and July) and fall (September, October, and November) of 2013. Cougar Dam is a high-head flood-control dam, and the water temperature control tower enables depth-specific water withdrawals to facilitate adjustment of water temperatures released downstream of the dam. The acoustic cameras were positioned at the upstream entrance of the tower to monitor free-ranging subyearling and yearling-size juvenile Chinook salmon (Oncorhynchus tshawytscha). Because of the large size discrepancy, we could distinguish juvenile Chinook salmon from their predators, which enabled us to measure predators and prey in areas adjacent to the entrance of the tower. We used linear models to quantify and assess operational and environmental factors—such as time of day, discharge, and water temperature—that may influence juvenile Chinook salmon movements within the beam of the acoustic cameras. Although extensive milling behavior of fish near the structure may have masked directed movement of fish and added unpredictability to fish movement models, the acoustic-camera technology enabled us to ascertain the general behavior of discrete size classes of fish. Fish travel speed, direction of travel, and counts of fish moving toward the water temperature control tower primarily were influenced by the amount of water being discharged through the dam.

  20. An evaluation of fish behavior upstream of the water temperature control tower at Cougar Dam, Oregon, using acoustic cameras, 2013

    USGS Publications Warehouse

    Adams, Noah S.; Smith, Collin; Plumb, John M.; Hansen, Gabriel S.; Beeman, John W.

    2015-01-01

    This report describes the initial year of a 2-year study to determine the feasibility of using acoustic cameras to monitor fish movements to help inform decisions about fish passage at Cougar Dam near Springfield, Oregon. Specifically, we used acoustic cameras to measure fish presence, travel speed, and direction adjacent to the water temperature control tower in the forebay of Cougar Dam during the spring (May, June, and July) and fall (September, October, and November) of 2013. Cougar Dam is a high-head flood-control dam, and the water temperature control tower enables depth-specific water withdrawals to facilitate adjustment of water temperatures released downstream of the dam. The acoustic cameras were positioned at the upstream entrance of the tower to monitor free-ranging subyearling and yearling-size juvenile Chinook salmon (Oncorhynchus tshawytscha). Because of the large size discrepancy, we could distinguish juvenile Chinook salmon from their predators, which enabled us to measure predators and prey in areas adjacent to the entrance of the tower. We used linear models to quantify and assess operational and environmental factors—such as time of day, discharge, and water temperature—that may influence juvenile Chinook salmon movements within the beam of the acoustic cameras. Although extensive milling behavior of fish near the structure may have masked directed movement of fish and added unpredictability to fish movement models, the acoustic-camera technology enabled us to ascertain the general behavior of discrete size classes of fish. Fish travel speed, direction of travel, and counts of fish moving toward the water temperature control tower primarily were influenced by the amount of water being discharged through the dam.

  1. A Preliminary Evaluation of Near-Transducer Velocities Collected with Low-Blank Acoustic Doppler Current Profiler

    USGS Publications Warehouse

    Gartner, J.W.; Ganju, N.K.

    2002-01-01

    Many streams and rivers for which the US Geological Survey must provide discharge measurements are too shallow to apply existing acoustic Doppler current profiler techniques for flow measurements of satisfactory quality. Because the same transducer is used for both transmitting and receiving acoustic signals in most Doppler current profilers, some small time delay is required for acoustic "ringing" to be damped out of transducers before meaningful measurements can be made. The result of that time delay is that velocity measurements cannot be made close to the transducer thus limiting the usefulness of these instruments in shallow regions. Manufacturers and users are constantly striving for improvements to acoustic instruments which would permit useful discharge measurements in shallow rivers and streams that are still often measured with techniques and instruments more than a century old. One promising area of advance appeared to be reduction of time delay (blank) required between transmitting and receiving signals during acoustic velocity measurements. Development of a low- or zero-blank transducer by RD Instruments3 held promise that velocity measurements could be made much closer to the transducer and thus in much shallower water. Initial experience indicates that this is not the case; limitation of measurement quality appears to be related to the physical presence of the transducer itself within the flow field. The limitation may be the result of changes to water flow pattern close to the transducer rather than transducer ringing characteristics as a function of blanking distance. Results of field experiments are discussed that support this conclusion and some minimum measurement distances from transducer are suggested based on water current speed and ADCP sample modes.

  2. Relationship of acoustic gain to aided threshold improvement in children.

    PubMed

    Jirsa, R E; Norris, T W

    1978-08-01

    Aided threshold improvement obtained by 12 hearing-impaired children was compared to the acoustic gain of their hearing aids using both the traditional 2-cc coupler and a variable volume coupler designed to approximate real ear volume in children. Results indicated that acoustic gain determined in the 2-cc coupler underestimated aided threshold improvement by approximately 8.7 dB. Use of the variable volume coupler to determine acoustic gain, however, adequately predicted aided improvement at comfort setting. Use of the variable volume coupler in hearing-aid fittings for children is discussed with special emphasis on preventing over-amplification.

  3. 24 CFR 3280.511 - Comfort cooling certificate and information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Comfort cooling certificate and... § 3280.511 Comfort cooling certificate and information. (a) The manufactured home manufacturer shall permanently affix a “Comfort Cooling Certificate” to an interior surface of the home that is readily...

  4. The Role of Interpersonal Comfort in Mentoring Relationships

    ERIC Educational Resources Information Center

    Allen, Tammy D.; Day, Rachel; Lentz, Elizabeth

    2005-01-01

    This research examined interpersonal comfort as a potential mediating mechanism in mentoring relationships. Results indicated that interpersonal comfort mediated the relationship between gender similarity and protege reports of career and psychosocial mentoring. Contrary to prediction, interpersonal comfort did not mediate relationships involving…

  5. Walking after Stroke: Comfortable versus Maximum Safe Speed.

    ERIC Educational Resources Information Center

    Bohannon, Richard W.

    1992-01-01

    This study attempted to (1) determine whether stroke patients (n=20) can safely increase their walking speed above that of comfortable walking; (2) describe the relationship between comfortable and maximum safe walking speed; and (3) examine correlations between maximum and comfortable speeds and a functional walking score. Subjects were able to…

  6. Heartwarming memories: Nostalgia maintains physiological comfort.

    PubMed

    Zhou, Xinyue; Wildschut, Tim; Sedikides, Constantine; Chen, Xiaoxi; Vingerhoets, Ad J J M

    2012-08-01

    Nostalgia, a sentimental longing or wistful affection for the past, is a predominantly positive and social emotion. Recent evidence suggests that nostalgia maintains psychological comfort. Here, we propose, and document in five methodologically diverse studies, a broader homeostatic function for nostalgia that also encompasses the maintenance of physiological comfort. We show that nostalgia--an emotion with a strong connotation of warmth--is triggered by coldness. Participants reported stronger nostalgia on colder (vs. warmer) days and in a cold (vs. neutral or warm) room. Nostalgia, in turn, modulates the interoceptive feeling of temperature. Higher levels of music-evoked nostalgia predicted increased physical warmth, and participants who recalled a nostalgic (vs. ordinary autobiographical) event perceived ambient temperature as higher. Finally, and consistent with the close central nervous system integration of temperature and pain sensations, participants who recalled a nostalgic (vs. ordinary autobiographical) event evinced greater tolerance to noxious cold. PMID:22390713

  7. Heartwarming memories: Nostalgia maintains physiological comfort.

    PubMed

    Zhou, Xinyue; Wildschut, Tim; Sedikides, Constantine; Chen, Xiaoxi; Vingerhoets, Ad J J M

    2012-08-01

    Nostalgia, a sentimental longing or wistful affection for the past, is a predominantly positive and social emotion. Recent evidence suggests that nostalgia maintains psychological comfort. Here, we propose, and document in five methodologically diverse studies, a broader homeostatic function for nostalgia that also encompasses the maintenance of physiological comfort. We show that nostalgia--an emotion with a strong connotation of warmth--is triggered by coldness. Participants reported stronger nostalgia on colder (vs. warmer) days and in a cold (vs. neutral or warm) room. Nostalgia, in turn, modulates the interoceptive feeling of temperature. Higher levels of music-evoked nostalgia predicted increased physical warmth, and participants who recalled a nostalgic (vs. ordinary autobiographical) event perceived ambient temperature as higher. Finally, and consistent with the close central nervous system integration of temperature and pain sensations, participants who recalled a nostalgic (vs. ordinary autobiographical) event evinced greater tolerance to noxious cold.

  8. Phantom evaluation of stacked-type dual-frequency 1-3 composite transducers: A feasibility study on intracavitary acoustic angiography.

    PubMed

    Kim, Jinwook; Li, Sibo; Kasoji, Sandeep; Dayton, Paul A; Jiang, Xiaoning

    2015-12-01

    In this paper, we present phantom evaluation results of a stacked-type dual-frequency 1-3 piezoelectric composite transducer as a feasibility study for intracavitary acoustic angiography. Our previous design (6.5/30 MHz PMN-PT single crystal transducer) for intravascular contrast ultrasound imaging exhibited a contrast-to-tissue ratio (CTR) of 12 dB with a penetration depth of 2.5 mm. For improved penetration depth (>3 mm) and comparable contrast-to-tissue ratio (>12 dB), we evaluated a lower frequency 2/14 MHz PZT 1-3 composite transducer. Superharmonic imaging performance of this transducer and a detailed characterization of key parameters for acoustic angiography are presented. The 2/14 MHz arrangement demonstrated a -6 dB fractional bandwidth of 56.5% for the transmitter and 41.8% for the receiver, and produced sufficient peak-negative pressures (>1.5 MPa) at 2 MHz to induce a strong nonlinear harmonic response from microbubble contrast agents. In an in-vitro contrast ultrasound study using a tissue mimicking phantom and 200 μm cellulose microvessels, higher harmonic microbubble responses, from the 5th through the 7th harmonics, were detected with a signal-to-noise ratio of 16 dB. The microvessels were resolved in a two-dimensional image with a -6dB axial resolution of 615 μm (5.5 times the wavelength of 14 MHz waves) and a contrast-to-tissue ratio of 16 dB. This feasibility study, including detailed explanation of phantom evaluation and characterization procedures for key parameters, will be useful for the development of future dual-frequency array transducers for intracavitary acoustic angiography. PMID:26112426

  9. Phantom evaluation of stacked-type dual-frequency 1-3 composite transducers: A feasibility study on intracavitary acoustic angiography.

    PubMed

    Kim, Jinwook; Li, Sibo; Kasoji, Sandeep; Dayton, Paul A; Jiang, Xiaoning

    2015-12-01

    In this paper, we present phantom evaluation results of a stacked-type dual-frequency 1-3 piezoelectric composite transducer as a feasibility study for intracavitary acoustic angiography. Our previous design (6.5/30 MHz PMN-PT single crystal transducer) for intravascular contrast ultrasound imaging exhibited a contrast-to-tissue ratio (CTR) of 12 dB with a penetration depth of 2.5 mm. For improved penetration depth (>3 mm) and comparable contrast-to-tissue ratio (>12 dB), we evaluated a lower frequency 2/14 MHz PZT 1-3 composite transducer. Superharmonic imaging performance of this transducer and a detailed characterization of key parameters for acoustic angiography are presented. The 2/14 MHz arrangement demonstrated a -6 dB fractional bandwidth of 56.5% for the transmitter and 41.8% for the receiver, and produced sufficient peak-negative pressures (>1.5 MPa) at 2 MHz to induce a strong nonlinear harmonic response from microbubble contrast agents. In an in-vitro contrast ultrasound study using a tissue mimicking phantom and 200 μm cellulose microvessels, higher harmonic microbubble responses, from the 5th through the 7th harmonics, were detected with a signal-to-noise ratio of 16 dB. The microvessels were resolved in a two-dimensional image with a -6dB axial resolution of 615 μm (5.5 times the wavelength of 14 MHz waves) and a contrast-to-tissue ratio of 16 dB. This feasibility study, including detailed explanation of phantom evaluation and characterization procedures for key parameters, will be useful for the development of future dual-frequency array transducers for intracavitary acoustic angiography.

  10. Acoustic characteristics of vowel sounds in patients with Parkinson disease.

    PubMed

    Bang, Young-Im; Min, Kyunghoon; Sohn, Young H; Cho, Sung-Rae

    2013-01-01

    The purpose of this study was to define the acoustic voice and speech characteristics of patients with Parkinson disease (PD). Seven female patients with PD and seven female healthy controls participated in this study. Each subject was instructed to vocalize extended corner vowels (/a/, /e/, /i/, /u/) three times for at least 5 seconds at a comfortable voice loudness and tone. The voice was analyzed using the Praat program. As a result, female patients with PD showed a significant increase in jitter and noise-to-harmonics ratio (NHR). In addition, F1 and F2 among the PD patients demonstrated asymmetric centralization of unrounded vowels (/a/, /e/, /i/) in high/low/front/back positions of the tongue, consequently leading to a significant decrease in vowel space area, compared to healthy controls. This study showed the acoustic characteristics of vowel sounds not only by laryngeal variables such as abnormal jitter and NHR, but also by articulatory variables such as asymmetric centralization and reduced vowel space area in female patients with PD. Therefore, it is important to use these objective and sensitive variables to evaluate the status or severity of hypokinetic dysarthria in patients with PD.

  11. Perceived Competence and Comfort in Respiratory Protection

    PubMed Central

    Burgel, Barbara J.; Novak, Debra; Burns, Candace M.; Byrd, Annette; Carpenter, Holly; Gruden, MaryAnn; Lachat, Ann; Taormina, Deborah

    2015-01-01

    In response to the Institute of Medicine (2011) report Occupational Health Nurses and Respiratory Protection: Improving Education and Training, a nationwide survey was conducted in May 2012 to assess occupational health nurses’ educational preparation, roles, responsibilities, and training needs in respiratory protection. More than 2,000 occupational health nurses responded; 83% perceived themselves as competent, proficient, or expert in respiratory protection, reporting moderate comfort with 12 respiratory program elements. If occupational health nurses had primary responsibility for the respiratory protection program, they were more likely to perceive higher competence and more comfort in respiratory protection, after controlling for occupational health nursing experience, highest education, occupational health nursing certification, industry sector, Association of Occupational Health Professionals in Healthcare membership, taking a National Institute for Occupational Safety and Health spirometry course in the prior 5 years, and perceiving a positive safety culture at work. These survey results document high perceived competence and comfort in respiratory protection. These findings support the development of targeted educational programs and interprofessional competencies for respiratory protection. PMID:23429638

  12. Micro- and nano-force evaluation of bioengineered muscle cells: a non-contact two-dimensional biosensing using surface acoustic wave devices.

    PubMed

    Wong, Yoke-Rung

    2015-08-01

    A high degree of cell-generated force measurement is required to evaluate the biomechanical performance of bioengineered muscle tissues. However, the conventional cantilever types of direct force measurement methods have limitations in developing a non-contact two-dimensional force sensing device for a single muscle cell. In this paper, a method is proposed and discussed by using focused surface acoustic wave and magneto-optic Kerr measurements. To depict the capability of the proposed method, a conceptual design of such a sensory device is demonstrated for non-contact two-dimensional force measurement of a single muscle cell.

  13. Evaluating the Acoustic Effect of Over-the-Rotor Foam-Metal Liner Installed on a Low Speed Fan Using Virtual Rotating Microphone Imaging

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Dougherty, Robert P.; Walker, Bruce E.

    2010-01-01

    An in-duct beamforming technique for imaging rotating broadband fan sources has been used to evaluate the acoustic characteristics of a Foam-Metal Liner installed over-the-rotor of a low-speed fan. The NASA Glenn Research Center s Advanced Noise Control Fan was used as a test bed. A duct wall-mounted phased array consisting of several rings of microphones was employed. The data are mathematically resampled in the fan rotating reference frame and subsequently used in a conventional beamforming technique. The steering vectors for the beamforming technique are derived from annular duct modes, so that effects of reflections from the duct walls are reduced.

  14. The architecture of shopping centers: An acoustical perspective

    NASA Astrophysics Data System (ADS)

    Kusakawa, Marisa S.; Viveiros, Elvira B.

    2002-11-01

    This paper analyzes the current state-of-the-art of the architecture of shopping centers from an acoustical point of view. There has been a worldwide spread of such buildings, whose characteristics do not differ much across cultural or climatic conditions. Despite the success achieved as a commercial product for big and medium cities, the acoustical comfort of employees and consumers has not been of concern. The food court and recreational areas tend to be reverberant spaces and usually very noisy. The research aims to correlate modern architectural solutions and typical sound fields generated in these buildings, taking a Brazilian case study. Also intended is to establish guidelines for architects and planners in order to provide acoustical comfort.

  15. Thermal comfort of various building layouts with a proposed discomfort index range for tropical climate.

    PubMed

    Md Din, Mohd Fadhil; Lee, Yee Yong; Ponraj, Mohanadoss; Ossen, Dilshan Remaz; Iwao, Kenzo; Chelliapan, Shreeshivadasan

    2014-04-01

    Recent years have seen issues related to thermal comfort gaining more momentum in tropical countries. The thermal adaptation and thermal comfort index play a significant role in evaluating the outdoor thermal comfort. In this study, the aim is to capture the thermal sensation of respondents at outdoor environment through questionnaire survey and to determine the discomfort index (DI) to measure the thermal discomfort level. The results indicated that most respondents had thermally accepted the existing environment conditions although they felt slightly warm and hot. A strong correlation between thermal sensation and measured DI was also identified. As a result, a new discomfort index range had been proposed in association with local climate and thermal sensation of occupants to evaluate thermal comfort. The results had proved that the respondents can adapt to a wider range of thermal conditions.Validation of the questionnaire data at Putrajaya was done to prove that the thermal sensation in both Putrajaya and UTM was almost similar since they are located in the same tropical climate region. Hence, a quantitative field study on building layouts was done to facilitate the outdoor human discomfort level based on newly proposed discomfort index range. The results showed that slightly shaded building layouts of type- A and B exhibited higher temperature and discomfort index. The resultant adaptive thermal comfort theory was incorporated into the field studies as well. Finally, the study also showed that the DI values were highly dependent on ambient temperature and relative humidity but had fewer effects for solar radiation intensity.

  16. Social marketing meets health literacy: Innovative improvement of health care providers’ comfort with patient interaction

    PubMed Central

    Primack, Brian A.; Bui, Thuy; Fertman, Carl I.

    2010-01-01

    Objective It is essential to train health care providers to deliver care sensitive to the needs of diverse individuals with varying degrees of health literacy. We aimed to evaluate an innovative, theory-based, educational intervention involving social marketing and health literacy. Methods In 2006 at a large medical school, all first-year students were exposed to the intervention. They completed pre- and post-test anonymous surveys including demographic data, covariates, and key outcome variables. Paired t-tests and multiple linear regression were used to evaluate the intervention and to determine independent associations among the key outcome variables. Results Post-intervention scores were significantly higher than pre-intervention scores for social marketing (3.31 versus 1.90, p < 0.001), health literacy (3.41 versus 2.98, p < 0.001), and comfort in brochure development (3.11 versus 2.52, p < 0.001) (N = 83). After controlling for demographic and covariate data, health literacy and comfort in brochure development were independent predictors of comfort interacting with diverse populations. Conclusion A brief intervention involving social marketing and health literacy can improve skills that improve medical students’ comfort with patients of diverse backgrounds. Practice implications Health care providers can be taught educational principles and skills involved in developing effective patient education materials. These skills may improve providers’ comfort with direct patient interaction. PMID:17418522

  17. Thermal comfort of various building layouts with a proposed discomfort index range for tropical climate.

    PubMed

    Md Din, Mohd Fadhil; Lee, Yee Yong; Ponraj, Mohanadoss; Ossen, Dilshan Remaz; Iwao, Kenzo; Chelliapan, Shreeshivadasan

    2014-04-01

    Recent years have seen issues related to thermal comfort gaining more momentum in tropical countries. The thermal adaptation and thermal comfort index play a significant role in evaluating the outdoor thermal comfort. In this study, the aim is to capture the thermal sensation of respondents at outdoor environment through questionnaire survey and to determine the discomfort index (DI) to measure the thermal discomfort level. The results indicated that most respondents had thermally accepted the existing environment conditions although they felt slightly warm and hot. A strong correlation between thermal sensation and measured DI was also identified. As a result, a new discomfort index range had been proposed in association with local climate and thermal sensation of occupants to evaluate thermal comfort. The results had proved that the respondents can adapt to a wider range of thermal conditions.Validation of the questionnaire data at Putrajaya was done to prove that the thermal sensation in both Putrajaya and UTM was almost similar since they are located in the same tropical climate region. Hence, a quantitative field study on building layouts was done to facilitate the outdoor human discomfort level based on newly proposed discomfort index range. The results showed that slightly shaded building layouts of type- A and B exhibited higher temperature and discomfort index. The resultant adaptive thermal comfort theory was incorporated into the field studies as well. Finally, the study also showed that the DI values were highly dependent on ambient temperature and relative humidity but had fewer effects for solar radiation intensity. PMID:24679966

  18. Acoustic biosensors

    PubMed Central

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  19. Acoustic biosensors.

    PubMed

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  20. How "Does" the Comforting Process Work? An Empirical Test of an Appraisal-Based Model of Comforting

    ERIC Educational Resources Information Center

    Jones, Susanne M.; Wirtz, John G.

    2006-01-01

    Burleson and Goldsmith's (1998) comforting model suggests an appraisal-based mechanism through which comforting messages can bring about a positive change in emotional states. This study is a first empirical test of three causal linkages implied by the appraisal-based comforting model. Participants (N=258) talked about an upsetting event with a…

  1. The human thermoneutral and thermal comfort zones: Thermal comfort in your own skin blood flow

    PubMed Central

    Schlader, Zachary J

    2014-01-01

    Human thermoregulation is achieved via autonomic and behavioral responses. Autonomic responses involve 2 synchronous ‘components’. One counteracts large thermal perturbations, eliciting robust heat loss or gain (i.e., sweating or shivering). The other fends off smaller insults, relying solely on changes in sensible heat exchange (i.e., skin blood flow). This sensible component occurs within the thermoneutral zone [i.e., the ambient temperature range in which temperature regulation is achieved only by sensible heat transfer, without regulatory increases in metabolic heat production (e.g., shivering) or evaporative heat loss (e.g., sweating)].1 The combination of behavior and sensible heat exchange permits a range of conditions that are deemed thermally comfortable, which is defined as the thermal comfort zone.1 Notably, we spend the majority of our lives within the thermoneutral and thermal comfort zones. It is only when we are unable to stay within these zones that deleterious health and safety outcomes can occur (i.e., hypo- or hyperthermia). Oddly, although the thermoneutral zone and thermal preference (a concept similar to the thermal comfort zone) has been extensively studied in non-human animals, our understanding of human thermoregulation within the thermoneutral and thermal comfort zones remains rather crude. PMID:27226992

  2. The human thermoneutral and thermal comfort zones: Thermal comfort in your own skin blood flow.

    PubMed

    Schlader, Zachary J

    2015-01-01

    Human thermoregulation is achieved via autonomic and behavioral responses. Autonomic responses involve 2 synchronous 'components'. One counteracts large thermal perturbations, eliciting robust heat loss or gain (i.e., sweating or shivering). The other fends off smaller insults, relying solely on changes in sensible heat exchange (i.e., skin blood flow). This sensible component occurs within the thermoneutral zone [i.e., the ambient temperature range in which temperature regulation is achieved only by sensible heat transfer, without regulatory increases in metabolic heat production (e.g., shivering) or evaporative heat loss (e.g., sweating)].(1) The combination of behavior and sensible heat exchange permits a range of conditions that are deemed thermally comfortable, which is defined as the thermal comfort zone.(1) Notably, we spend the majority of our lives within the thermoneutral and thermal comfort zones. It is only when we are unable to stay within these zones that deleterious health and safety outcomes can occur (i.e., hypo- or hyperthermia). Oddly, although the thermoneutral zone and thermal preference (a concept similar to the thermal comfort zone) has been extensively studied in non-human animals, our understanding of human thermoregulation within the thermoneutral and thermal comfort zones remains rather crude.

  3. The human thermoneutral and thermal comfort zones: Thermal comfort in your own skin blood flow

    PubMed Central

    Schlader, Zachary J

    2015-01-01

    Human thermoregulation is achieved via autonomic and behavioral responses. Autonomic responses involve 2 synchronous ‘components’. One counteracts large thermal perturbations, eliciting robust heat loss or gain (i.e., sweating or shivering). The other fends off smaller insults, relying solely on changes in sensible heat exchange (i.e., skin blood flow). This sensible component occurs within the thermoneutral zone [i.e., the ambient temperature range in which temperature regulation is achieved only by sensible heat transfer, without regulatory increases in metabolic heat production (e.g., shivering) or evaporative heat loss (e.g., sweating)].1 The combination of behavior and sensible heat exchange permits a range of conditions that are deemed thermally comfortable, which is defined as the thermal comfort zone.1 Notably, we spend the majority of our lives within the thermoneutral and thermal comfort zones. It is only when we are unable to stay within these zones that deleterious health and safety outcomes can occur (i.e., hypo- or hyperthermia). Oddly, although the thermoneutral zone and thermal preference (a concept similar to the thermal comfort zone) has been extensively studied in non-human animals, our understanding of human thermoregulation within the thermoneutral and thermal comfort zones remains rather crude. PMID:27226992

  4. Subjective evaluation of a concert hall's acoustics using a free-format-type questionnaire and comparison with objective measurements

    NASA Astrophysics Data System (ADS)

    Okano, Toshiyuki; Beranek, Leo L.

    2002-11-01

    A free-format type of audiences' judgment of the acoustical properties of a hall and music critics' writings were used as the basis for this study. These subjective responses are related to the Dai-Ichi Seimei Hall in Tokyo. This hall is an oval-shaped, one-balcony space, seating 767 persons. Its primary use is for various types of chamber music and solo-instrument performances. Eight acoustical attributes were investigated, ''reverberation,'' ''clarity,'' ''loudness,'' ''intimacy,'' ''spaciousness,'' ''balance,'' ''localization,'' and ''timbre,'' plus ''general impression.'' Subjective comments about these attributes were obtained. Objective measurements were made in the hall and are compared with those made in several similar-sized halls of two shapes. In the rear seats of two oval-shaped halls the strength factor GE (determined in the first 80 ms of the impulse response) was greater than the GE found in the rear seats of similar-sized rectangular halls. The subjective results and the objective measurements were closely correlated, especially for reverberation, clarity, and warmth (a subcomponent of timbre). It was suggested that the greater strength GE in the rear seats made the hall seem smaller and thus more intimate. The subjective comments also confirmed the hall's wide applicability, indicating that the acoustical characteristics used for its design were well chosen.

  5. Energy expenditure and comfort during Nordic walking with different pole lengths.

    PubMed

    Hansen, Ernst A; Smith, Gerald

    2009-07-01

    Energy expenditure and comfort for Nordic walking with self-selected and 7.5-cm shorter poles and ordinary walking were measured during uphill (12 degrees ), downhill (12 degrees ), and horizontally. Twelve (11 women and 1 man) Nordic walking practitioners participated (mean +/- SEM: 171.5 +/- 1.5 cm, 67.0 +/- 2.7 kg, 50.6 +/- 2.4 years, and maximal oxygen uptake of 43.4 +/- 2.8 mL x kg(-1) x min(-1)). Energy expenditure was calculated from oxygen uptake and comfort was self-rated. Differences in physiological responses between the 3 locomotion types at each slope were first analyzed by a 1-way analysis of variance. In case of significance, Student's paired samples 2-tailed t-test was applied twice to test for differences between the 2 pole lengths and between Nordic walking (with self-selected pole length) and ordinary walking. The corresponding differences in comfort were evaluated by a Wilcoxon matched pairs test. The relative exercise intensity during Nordic walking with self-selected pole length ranged between approximately 44 and 87% of the maximal oxygen uptake across the different slopes. For comparison, it ranged between approximately 29 and 80% during ordinary walking. Uphill Nordic walking with short poles compared with poles of self-selected length caused 3% greater energy expenditure. Notwithstanding, comfort was similar. Horizontally and downhill energy expenditure and comfort were similar between pole lengths. Compared with ordinary walking, Nordic walking required as much as 67% greater energy expenditure. Comfort was similar for ordinary and Nordic walking for each slope. In conclusion, shorter poles caused greater energy expenditure during uphill Nordic walking, whereas comfort was similar to poles of self-selected length. The substantially enhanced energy expenditure of Nordic walking compared with previous studies reflects the vigorous technique used here.

  6. Evaluation of a Laser-Acoustic System for Continuously Monitoring Suspended-Sediment Concentration and Grain Size in the Colorado River in Grand Canyon

    NASA Astrophysics Data System (ADS)

    Topping, D. J.; Melis, T. S.; Rubin, D. M.

    2003-12-01

    Sandbars and other sandy deposits in and along the Colorado River in Grand Canyon National Park (GCNP) were an integral part of the pre-dam riverscape, and are important for habitat, protecting archeological sites, and recreation. These deposits have eroded substantially following the 1963 closure of Glen Canyon Dam that reduced the supply of sand at the upstream boundary of GCNP by about 94%; sandbars in the upstream portion of Grand Canyon have decreased in size by about 25% during only the last 15 years. Recent work has shown that sand transport in the post-dam river is supply limited, and is equally regulated by the discharge of water and short-term changes in the grain size of sand available for transport. During and following tributary floods, fine sand supplied to the Colorado River travels downstream as an elongating sediment wave. As the front of a sediment wave passes a given location, sand on the bed first fines and sand-transport rates increase independently of the discharge of water. Subsequently, the bed is winnowed and sand-transport rates decrease independently of discharge. By virtue of this process, sand supplied by tributaries is typically exported from the upstream portion of Grand Canyon within months under normal dam releases. Thus, newly input sand may be available to rebuild sandbars during controlled floods conducted only following large tributary floods. Accurate monitoring of sand transport in such a river requires frequent measurements of suspended-sediment concentration and grain size, and cannot be accomplished by using stable sediment-rating curves constructed from a sparser dataset of suspended-sediment measurements. To monitor sediment transport in the Colorado River, we have designed and are evaluating a laser-acoustic system for measuring the concentration and grain size of suspended sediment every 15 minutes. This system consists of (1) a subaqueously deployed laser-diffraction instrument (either a LISST 100 or a LISST 25X

  7. Aspects of seat modelling for seating comfort analysis.

    PubMed

    Verver, M M; de Lange, R; van Hoof, J; Wismans, J S H M

    2005-01-01

    The development of more comfortable seats is an important issue in the automotive industry. However, the development of new car seats is very time consuming and costly since it is typically based on experimental evaluation using prototypes. Computer models of the human-seat interaction could accelerate this process. The objective of this paper is to establish a protocol for the development of seat models using numerically efficient simulation techniques. The methodology is based on multi-body techniques: arbitrary surfaces, providing an accurate surface description, are attached to rigid bodies. The bodies are connected by kinematic joints, representing the seat back recliner and head restraint joint. Properties of the seat foam and frame have been lumped together. Further, experiments have been defined to characterise the mechanical properties required for the seat model for comfort applications. The protocol has been exemplified using a standard car seat. The seat model has been validated based on experiments with rigid loading devices with human-like shapes in terms of force-deflection characteristics. The response of the seat model agrees well with the experimental results. Therefore the presented method can be a useful tool in the seat development process, especially in early stages of the design process.

  8. The relationship between end-state comfort effects and memory performance in serial and free recall.

    PubMed

    Logan, S Wood; Fischman, Mark G

    2011-07-01

    In two experiments we examined the relationship between end-state comfort effects and memory performance in serial and free recall. In Experiment 1, 24 university students completed a bimanual end-state comfort task and a memory task. Participants viewed a series of 11 letters, then performed the bimanual overturned glass task in which they simultaneously moved two glasses from an upper shelf to a lower shelf, and then recalled the letters in either serial or free recall conditions. Memory recall was evaluated based on the presence or absence of primacy and recency effects. The end-state comfort effect was assessed by the percentage of initial hand positions that allowed the hands to end up in a comfortable thumbs-up posture. The end-state comfort effect was present in both memory conditions. The results revealed the disappearance of the recency effect in serial and free recall, although the effect was much stronger during serial recall. In Experiment 2, we asked whether simpler motor tasks might bring back the recency effect. Forty-eight participants completed either a bimanual or unimanual task that involved moving non-descript plastic cylinder(s) from an upper shelf to a lower shelf. An unexpected finding was that even after performance of the simpler motor tasks, the recency effect was still absent. The disappearance of the recency effect, regardless of the complexity of the motor task, suggests a reciprocal influence of physical action and cognitive processes, which we interpret as a basic concurrence cost.

  9. An Open Source "Smart Lamp" for the Optimization of Plant Systems and Thermal Comfort of Offices.

    PubMed

    Salamone, Francesco; Belussi, Lorenzo; Danza, Ludovico; Ghellere, Matteo; Meroni, Italo

    2016-03-07

    The article describes the design phase, development and practical application of a smart object integrated in a desk lamp and called "Smart Lamp", useful to optimize the indoor thermal comfort and energy savings that are two important workplace issues where the comfort of the workers and the consumption of the building strongly affect the economic balance of a company. The Smart Lamp was built using a microcontroller, an integrated temperature and relative humidity sensor, some other modules and a 3D printer. This smart device is similar to the desk lamps that are usually found in offices but it allows one to adjust the indoor thermal comfort, by interacting directly with the air conditioner. After the construction phase, the Smart Lamp was installed in an office normally occupied by four workers to evaluate the indoor thermal comfort and the cooling consumption in summer. The results showed how the application of the Smart Lamp effectively reduced the energy consumption, optimizing the thermal comfort. The use of DIY approach combined with read-write functionality of websites, blog and social platforms, also allowed to customize, improve, share, reproduce and interconnect technologies so that anybody could use them in any occupied environment.

  10. An Open Source "Smart Lamp" for the Optimization of Plant Systems and Thermal Comfort of Offices.

    PubMed

    Salamone, Francesco; Belussi, Lorenzo; Danza, Ludovico; Ghellere, Matteo; Meroni, Italo

    2016-01-01

    The article describes the design phase, development and practical application of a smart object integrated in a desk lamp and called "Smart Lamp", useful to optimize the indoor thermal comfort and energy savings that are two important workplace issues where the comfort of the workers and the consumption of the building strongly affect the economic balance of a company. The Smart Lamp was built using a microcontroller, an integrated temperature and relative humidity sensor, some other modules and a 3D printer. This smart device is similar to the desk lamps that are usually found in offices but it allows one to adjust the indoor thermal comfort, by interacting directly with the air conditioner. After the construction phase, the Smart Lamp was installed in an office normally occupied by four workers to evaluate the indoor thermal comfort and the cooling consumption in summer. The results showed how the application of the Smart Lamp effectively reduced the energy consumption, optimizing the thermal comfort. The use of DIY approach combined with read-write functionality of websites, blog and social platforms, also allowed to customize, improve, share, reproduce and interconnect technologies so that anybody could use them in any occupied environment. PMID:26959035

  11. Energy usage while maintaining thermal comfort: A case study of a UNT dormitory

    NASA Astrophysics Data System (ADS)

    Gambrell, Dusten

    Campus dormitories for the University of North Texas house over 5500 students per year; each one of them requires certain comfortable living conditions while they live there. There is an inherit amount of money required in order to achieve minimal comfort levels; the cost is mostly natural gas for water and room heating and electricity for cooling, lighting and peripherals. The US Department of Energy has developed several programs to aid in performing energy simulations to help those interested design more cost effective building designs. Energy-10 is such a program that allows users to conduct whole house evaluations by reviewing and altering a few parameters such as building materials, solar heating, energy efficient windows etc. The idea of this project was to recreate a campus dormitory and try to emulate existent energy consumption then try to find ways of lowering that usage while maintaining a high level of personal comfort.

  12. A Study of Student Consultants' Comfort Levels with Research-Related Tasks

    ERIC Educational Resources Information Center

    Holler Phillips, Carissa M.

    2011-01-01

    Student consulting is a form of problem-based learning through which students work on strategic issues for organizations. To explore how students perceive their research-related tasks, 15 student consultants were asked to evaluate their comfort levels with seven tasks--adapted from the Association of College and Research Libraries' Information…

  13. Evaluation of B/A nonlinear parameter using an acoustic self-calibrated pulse-echo method

    SciTech Connect

    Vander Meulen, F.; Haumesser, L.

    2008-05-26

    The objective of this work is to develop an easy-to-build and robust setup for measuring the nonlinearity parameter B/A in fluids using ultrasound. The method is based on the pulse-echo technique, using a single element broadband acoustic transducer, and requires electrical signal measurements. Results obtained in water and denatured alcohol validate the proposed procedure. The choice of a suitable primary wave frequency is discussed with regard to the transducer sensitivity. Further, the influence of the perturbations introduced by the experimental device nonlinearities, and the role of the reflector on the measured second harmonic field amplitude are investigated.

  14. LyP-1 ultrasonic microbubbles targeting to cancer cell as tumor bio-acoustics markers or drug carriers: targeting efficiency evaluation in, microfluidic channels.

    PubMed

    Li, Xiang; Jin, Qiaofeng; Chen, Tan; Zhang, Baoyue; Zheng, Rongqin; Wang, Zhanhui; Zheng, Hairong

    2009-01-01

    Using ultrasonic contrast microbubbles as acoustic biomarkers and drug carrier vehicles by conjugating tumor specific antibody to microbubbles has shown great potential in ultrasonic tumor molecular imaging or drug-delivery and therapy. Microbubble probe targeting efficiency is one of the major challenges. In this study, we developed a novel method to evaluate the targeting capability and efficiency of microbubbles to cells, and more specifically, microbubbles binding LyP-1 (a cyclic nonapeptide acid peptide) target to cancer cell within a microfluidic system. The micro cell sieves within the microfludic channels could trap the tumor cells and enhance the microbubble's interaction with the cell. Assisted with the controllable fluid shear stress, the microbubble's targeting to the cell and the corresponding affinity efficiency could be quantitatively evaluated under a florescent microscope. The system provides a useful low-cost high efficient in vitro platform for studying microbubble-cell interaction for ultrasonic tumor molecular imaging or drug-delivery and therapy.

  15. Integrating fluorescent dye flow-curve testing and acoustic Doppler velocimetry profiling for in situ hydraulic evaluation and improvement of clarifier performance.

    PubMed

    Tarud, F; Aybar, M; Pizarro, G; Cienfuegos, R; Pastén, P

    2010-08-01

    Enhancing the performance of clarifiers requires a thorough understanding of their hydraulics. Fluorescence spectroscopy and acoustic doppler velocimeter (ADV) profiling generally have been used separately to evaluate secondary settlers. We propose that simultaneous use of these techniques is needed to obtain a more reliable and useful evaluation. Experiments were performed on laboratory- and full-scale clarifiers. Factors affecting Fluorescein and Rhodamine 6G properties were identified. Underestimations up to 500% in fluorescence intensities may be derived from differential fluorescence quenching by oxygen. A careful control and interpretation of fluorescent dye experiments is needed to minimize artifacts in real settings. While flow-curve tests constructed under controlled conditions provided a more accurate overall quantitative estimation of the hydraulic performance, ADV velocity and turbulence profiling provided a detailed spatial understanding of flow patterns that was used to troubleshoot and fix the causes of hydraulic short-circuits.

  16. Integrating fluorescent dye flow-curve testing and acoustic Doppler velocimetry profiling for in situ hydraulic evaluation and improvement of clarifier performance.

    PubMed

    Tarud, F; Aybar, M; Pizarro, G; Cienfuegos, R; Pastén, P

    2010-08-01

    Enhancing the performance of clarifiers requires a thorough understanding of their hydraulics. Fluorescence spectroscopy and acoustic doppler velocimeter (ADV) profiling generally have been used separately to evaluate secondary settlers. We propose that simultaneous use of these techniques is needed to obtain a more reliable and useful evaluation. Experiments were performed on laboratory- and full-scale clarifiers. Factors affecting Fluorescein and Rhodamine 6G properties were identified. Underestimations up to 500% in fluorescence intensities may be derived from differential fluorescence quenching by oxygen. A careful control and interpretation of fluorescent dye experiments is needed to minimize artifacts in real settings. While flow-curve tests constructed under controlled conditions provided a more accurate overall quantitative estimation of the hydraulic performance, ADV velocity and turbulence profiling provided a detailed spatial understanding of flow patterns that was used to troubleshoot and fix the causes of hydraulic short-circuits. PMID:20853746

  17. Suitability of different comfort indices for the prediction of thermal conditions in tree-covered outdoor spaces in arid cities

    NASA Astrophysics Data System (ADS)

    Ruiz, María Angélica; Correa, Erica Norma

    2015-10-01

    Outdoor thermal comfort is one of the most influential factors in the habitability of a space. Thermal level is defined not only by climate variables but also by the adaptation of people to the environment. This study presents a comparison between inductive and deductive thermal comfort models, contrasted with subjective reports, in order to identify which of the models can be used to most correctly predict thermal comfort in tree-covered outdoor spaces of the Mendoza Metropolitan Area, an intensely forested and open city located in an arid zone. Interviews and microclimatic measurements were carried out in winter 2010 and in summer 2011. Six widely used indices were selected according to different levels of complexity: the Temperature-Humidity Index (THI), Vinje's Comfort Index (PE), Thermal Sensation Index (TS), the Predicted Mean Vote (PMV), the COMFA model's energy balance (S), and the Physiological Equivalent Temperature (PET). The results show that the predictive models evaluated show percentages of predictive ability lower than 25 %. Despite this low indicator, inductive methods are adequate for obtaining a diagnosis of the degree and frequency in which a space is comfortable or not whereas deductive methods are recommended to influence urban design strategies. In addition, it is necessary to develop local models to evaluate perceived thermal comfort more adequately. This type of tool is very useful in the design and evaluation of the thermal conditions in outdoor spaces, based not only to climatic criteria but also subjective sensations.

  18. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens. 9 figs.

  19. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  20. Force Limiting Vibration Tests Evaluated from both Ground Acoustic Tests and FEM Simulations of a Flight Like Vehicle System Assembly

    NASA Technical Reports Server (NTRS)

    Smith, Andrew; LaVerde, Bruce; Waldon, James; Hunt, Ron

    2014-01-01

    Marshall Space Flight Center has conducted a series of ground acoustic tests with the dual goals of informing analytical judgment, and validating analytical methods when estimating vibroacoustic responses of launch vehicle subsystems. The process of repeatedly correlating finite element-simulated responses with test-measured responses has assisted in the development of best practices for modeling and post-processing. In recent work, force transducers were integrated to measure interface forces at the base of avionics box equipment. Other force data was indirectly measured using strain gauges. The combination of these direct and indirect force measurements has been used to support and illustrate the advantages of implementing the Force Limiting approach for equipment qualification tests. The comparison of force response from integrated system level tests to measurements at the same locations during component level vibration tests provides an excellent illustration. A second comparison of the measured response cases from the system level acoustic tests to finite element simulations has also produced some principles for assessing the suitability of Finite Element Models (FEMs) for making vibroacoustics estimates. The results indicate that when FEM models are employed to guide force limiting choices, they should include sufficient detail to represent the apparent mass of the system in the frequency range of interest.

  1. Passenger safety, health, and comfort: a review.

    PubMed

    Rayman, R B

    1997-05-01

    Since the birth of aviation medicine approximately 80 yrs ago, practitioners and scientists have given their attention primarily to flight deck crew, cabin crew, and ground support personnel. However, in more recent years we have broadened our horizons to include the safety, health, and comfort of passengers flying commercial aircraft. This will be even more compelling as more passengers take to the air in larger aircraft and flying longer hours to more distant destinations. Further, we can expect to see more older passengers because people in many countries are living longer, healthier lives. The author first discusses the stresses imposed by ordinary commercial flight upon travelers such as airport tumult, barometric pressure changes, immobility, jet lag, noise/ vibration, and radiation. Medical considerations are next addressed describing inflight illness and medical care capability aboard U.S. air carriers. Passenger safety, cabin air quality, and the preventive medicine aspects of air travel are next reviewed in the context of passenger safety, health, and comfort. Recommendations are addressed to regulator agencies, airlines aircraft manufacturers, and the aerospace medicine community.

  2. Evaluating the Feasibility of Acoustic Radiation Force Impulse Shear Wave Elasticity Imaging of the Uterine Cervix With an Intracavity Array: A Simulation Study

    PubMed Central

    Feltovich, Helen; Homyk, Andrew D.; Carlson, Lindsey C.; Hall, Timothy J.

    2015-01-01

    The uterine cervix softens, shortens, and dilates throughout pregnancy in response to progressive disorganization of its layered collagen microstructure. This process is an essential part of normal pregnancy, but premature changes are associated with preterm birth. Clinically, there are no reliable noninvasive methods to objectively measure cervical softening or assess cervical microstructure. The goal of these preliminary studies was to evaluate the feasibility of using an intracavity ultrasound array to generate acoustic radiation force impulse (ARFI) excitations in the uterine cervix through simulation, and to optimize the acoustic radiation force (ARF) excitation for shear wave elasticity imaging (SWEI) of the tissue stiffness. The cervix is a unique soft tissue target for SWEI because it has significantly greater acoustic attenuation (α = 1.3 to 2.0 dB·cm−1·MHz−1) than other soft tissues, and the pathology being studied tends to lead to an increase in tissue compliance, with healthy cervix being relatively stiff compared with other soft tissues (E ≈ 25 kPa). Additionally, the cervix can only be accessed in vivo using a transvaginal or catheter-based array, which places additional constraints on the excitation focal characteristics that can be used during SWEI. Finite element method (FEM) models of SWEI show that larger-aperture, catheter-based arrays can utilize excitation frequencies up to 7 MHz to generate adequate focal gain up to focal depths 10 to 15 mm deep, with higher frequencies suffering from excessive amounts of near-field acoustic attenuation. Using full-aperture excitations can yield ~40% increases in ARFI-induced displacements, but also restricts the depth of field of the excitation to ~0.5 mm, compared with 2 to 6 mm, which limits the range that can be used for shear wave characterization of the tissue. The center-frequency content of the shear wave particle velocity profiles ranges from 1.5 to 2.5 kHz, depending on the focal

  3. Micro acoustic spectrum analyzer

    DOEpatents

    Schubert, W. Kent; Butler, Michael A.; Adkins, Douglas R.; Anderson, Larry F.

    2004-11-23

    A micro acoustic spectrum analyzer for determining the frequency components of a fluctuating sound signal comprises a microphone to pick up the fluctuating sound signal and produce an alternating current electrical signal; at least one microfabricated resonator, each resonator having a different resonant frequency, that vibrate in response to the alternating current electrical signal; and at least one detector to detect the vibration of the microfabricated resonators. The micro acoustic spectrum analyzer can further comprise a mixer to mix a reference signal with the alternating current electrical signal from the microphone to shift the frequency spectrum to a frequency range that is a better matched to the resonant frequencies of the microfabricated resonators. The micro acoustic spectrum analyzer can be designed specifically for portability, size, cost, accuracy, speed, power requirements, and use in a harsh environment. The micro acoustic spectrum analyzer is particularly suited for applications where size, accessibility, and power requirements are limited, such as the monitoring of industrial equipment and processes, detection of security intrusions, or evaluation of military threats.

  4. Influence of the Si particle size on the mechanical stability of Si-based electrodes evaluated by in-operando dilatometry and acoustic emission

    NASA Astrophysics Data System (ADS)

    Tranchot, A.; Idrissi, H.; Thivel, P.-X.; Roué, L.

    2016-10-01

    The influence of the Si particle size (85 nm versus 230 nm) on the mechanical stability of composite Si/C/carboxymethyl cellulose (CMC) electrodes is evaluated from in-operando dilatometry and acoustic emission measurements. A lower, more progressive and more reversible expansion/contraction of the electrode is observed with the Si 230 nm powder, with a maximum expansion of ∼140% and a residual irreversible expansion of ∼25% measured during the first cycle compared to ∼350% and ∼90% for the Si 85 nm based electrode. Moreover, during the 2nd cycle, an abrupt and very large expansion/contraction (up to ∼400%) is observed for the Si 85 nm based electrode, which results in the irreversible cracking and exfoliation of the electrode as confirmed by post-mortem scanning electron microscopy observations. This is also in accordance with the more intensive acoustic activity measured during the Si 85 nm electrode cycling. The lower mechanical strength of the Si 85 nm electrode is interpreted as the consequence of an insufficient amount of CMC binder relative to the larger specific surface area of the Si 85 nm powder. This tends to be confirmed by the significant improvement of its electrochemical cycling performance as its CMC content is increased.

  5. Possibilities to improve the aircraft interior comfort experience.

    PubMed

    Vink, P; Bazley, C; Kamp, I; Blok, M

    2012-03-01

    Comfort plays an increasingly important role in the interior design of airplanes. Although ample research has been conducted on airplane design technology, only a small amount of public scientific information is available addressing the passenger's opinion. In this study, more than 10,000 internet trip reports and 153 passenger interviews were used to gather opinions about aspects which need to be improved in order to design a more comfortable aircraft interior. The results show clear relationships between comfort and legroom, hygiene, crew attention and seat/personal space. Passengers rate the newer planes significantly better than older ones, indicating that attention to design for comfort has proven effective. The study also shows that rude flight attendants and bad hygiene reduce the comfort experience drastically and that a high comfort rating is related to higher "fly again" values.

  6. Perceived Comfort of Indoor Environment and Users' Performance in Office Building with Smart Elements - case Study

    NASA Astrophysics Data System (ADS)

    Pilipová, Ivana; Vilčeková, Silvia

    2013-11-01

    A greater degree of awareness of comfort and productivity of building users according to post-occupancy evaluation and feedback of users in intelligent buildings is necessary. This report presents a summary of the results from a physical measurements, a post-occupancy evaluation study on perceived comfort of indoor environment and self-evaluation of occupant's performance in the new multifunctional 5 floor-building in city of Kosice, Slovakia. There were investigated degree of perceived comfort and user's performance with regard to objective measurement, respondents' response and building character. This case study has highlighted that influence of monitored factors of building with smart elements is positively received and wasn't determined their negative impact on perceived comfort of indoor environment and occupants' performance. Results show that respondents are mostly satisfied with their indoor environment conditions of workplace. Interviews with respondents detected they have not been perceived (negative) factors in workplace because they have been too concentric on the work and they have not felt discomfort.

  7. Structures and Acoustics Division

    NASA Technical Reports Server (NTRS)

    Acquaviva, Cynthia S.

    1999-01-01

    The Structures and Acoustics Division of NASA Glenn Research Center is an international leader in rotating structures, mechanical components, fatigue and fracture, and structural aeroacoustics. Included are disciplines related to life prediction and reliability, nondestructive evaluation, and mechanical drive systems. Reported are a synopsis of the work and accomplishments reported by the Division during the 1996 calendar year. A bibliography containing 42 citations is provided.

  8. Structures and Acoustics Division

    NASA Technical Reports Server (NTRS)

    Acquaviva, Cynthia S.

    2001-01-01

    The Structures and Acoustics Division of the NASA Glenn Research Center is an international leader in rotating structures, mechanical components, fatigue and fracture, and structural aeroacoustics. Included in this report are disciplines related to life prediction and reliability, nondestructive evaluation, and mechanical drive systems. Reported is a synopsis of the work and accomplishments completed by the Division during the 1997, 1998, and 1999 calendar years. A bibliography containing 93 citations is provided.

  9. The social comfort of wearable technology and gestural interaction.

    PubMed

    Dunne, Lucy E; Profita, Halley; Zeagler, Clint; Clawson, James; Gilliland, Scott; Do, Ellen Yi-Luen; Budd, Jim

    2014-01-01

    The "wearability" of wearable technology addresses the factors that affect the degree of comfort the wearer experiences while wearing a device, including physical, psychological, and social aspects. While the physical and psychological aspects of wearing technology have been investigated since early in the development of the field of wearable computing, the social aspects of wearability have been less fully-explored. As wearable technology becomes increasingly common on the commercial market, social wearability is becoming an ever-more-important variable contributing to the success or failure of new products. Here we present an analysis of social aspects of wearability within the context of the greater understanding of wearability in wearable technology, and focus on selected theoretical frameworks for understanding how wearable products are perceived and evaluated in a social context. Qualitative results from a study of social acceptability of on-body interactions are presented as a case study of social wearability.

  10. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk W.; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  11. The thematic structure of passenger comfort experience and its relationship to the context features in the aircraft cabin.

    PubMed

    Ahmadpour, Naseem; Lindgaard, Gitte; Robert, Jean-Marc; Pownall, Bernard

    2014-01-01

    This paper describes passenger comfort as an experience generated by the cabin interior features. The findings of previous studies are affirmed regarding a set of 22 context features. Passengers experience a certain level of comfort when these features impact their body and elicit subjective perceptions. New findings characterise these perceptions in the form of eight themes and outline their particular eliciting features. Comfort is depicted as a complex construct derived by passengers' perceptions beyond the psychological (i.e. peace of mind) and physical (i.e. physical well-being) aspects, and includes perceptual (e.g. proxemics) and semantic (e.g. association) aspects. The seat was shown to have a focal role in eliciting seven of those themes and impacting comfort through its diverse characteristics. In a subsequent study, a group of aircraft cabin interior designers highlighted the possibility of employing the eight themes and their eliciting features as a framework for design and evaluation of new aircraft interiors.

  12. Progress in thermal comfort research over the last twenty years.

    PubMed

    de Dear, R J; Akimoto, T; Arens, E A; Brager, G; Candido, C; Cheong, K W D; Li, B; Nishihara, N; Sekhar, S C; Tanabe, S; Toftum, J; Zhang, H; Zhu, Y

    2013-12-01

    Climate change and the urgency of decarbonizing the built environment are driving technological innovation in the way we deliver thermal comfort to occupants. These changes, in turn, seem to be setting the directions for contemporary thermal comfort research. This article presents a literature review of major changes, developments, and trends in the field of thermal comfort research over the last 20 years. One of the main paradigm shift was the fundamental conceptual reorientation that has taken place in thermal comfort thinking over the last 20 years; a shift away from the physically based determinism of Fanger's comfort model toward the mainstream and acceptance of the adaptive comfort model. Another noticeable shift has been from the undesirable toward the desirable qualities of air movement. Additionally, sophisticated models covering the physics and physiology of the human body were developed, driven by the continuous challenge to model thermal comfort at the same anatomical resolution and to combine these localized signals into a coherent, global thermal perception. Finally, the demand for ever increasing building energy efficiency is pushing technological innovation in the way we deliver comfortable indoor environments. These trends, in turn, continue setting the directions for contemporary thermal comfort research for the next decades.

  13. Passenger comfort response times as a function of aircraft motion

    NASA Technical Reports Server (NTRS)

    Rinalducci, E. J.

    1975-01-01

    The relationship between a passenger's response time of changes in level of comfort experienced as a function of aircraft motion was examined. The aircraft used in this investigation was capable of providing a wide range of vertical and transverse accelerations by means of direct lift flap control surfaces and side force generator surfaces in addition to normal control surfaces. Response times to changes in comfort were recorded along with the passenger's rating of comfort on a five point scale. In addition, a number of aircraft motion variables including vertical and transverse accelerations were also recorded. Results indicate some relationship between human comfort response times to reaction time data.

  14. A model to assess the comfort of automotive seat cushions.

    PubMed

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed.

  15. A model to assess the comfort of automotive seat cushions.

    PubMed

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed. PMID:25189755

  16. Progress in thermal comfort research over the last twenty years.

    PubMed

    de Dear, R J; Akimoto, T; Arens, E A; Brager, G; Candido, C; Cheong, K W D; Li, B; Nishihara, N; Sekhar, S C; Tanabe, S; Toftum, J; Zhang, H; Zhu, Y

    2013-12-01

    Climate change and the urgency of decarbonizing the built environment are driving technological innovation in the way we deliver thermal comfort to occupants. These changes, in turn, seem to be setting the directions for contemporary thermal comfort research. This article presents a literature review of major changes, developments, and trends in the field of thermal comfort research over the last 20 years. One of the main paradigm shift was the fundamental conceptual reorientation that has taken place in thermal comfort thinking over the last 20 years; a shift away from the physically based determinism of Fanger's comfort model toward the mainstream and acceptance of the adaptive comfort model. Another noticeable shift has been from the undesirable toward the desirable qualities of air movement. Additionally, sophisticated models covering the physics and physiology of the human body were developed, driven by the continuous challenge to model thermal comfort at the same anatomical resolution and to combine these localized signals into a coherent, global thermal perception. Finally, the demand for ever increasing building energy efficiency is pushing technological innovation in the way we deliver comfortable indoor environments. These trends, in turn, continue setting the directions for contemporary thermal comfort research for the next decades. PMID:23590514

  17. NREL Provides Guidance to Improve Thermal Comfort in High-Performance Homes (Fact Sheet)

    SciTech Connect

    Not Available

    2012-01-01

    This technical highlight describes NREL research to develop recommendations on HVAC system design and operating conditions to achieve optimal thermal comfort in high-performance homes. Researchers at the National Renewable Energy Laboratory (NREL) have developed recommendations to help residential heating, cooling, and ventilation (HVAC) designers select optimal supply inlet size and system operating conditions to maintain good thermal comfort in low heating and cooling load homes. This can be achieved by using high sidewall supply air jets to create proper combinations of air temperature and air motion in the occupied zone of the conditioned space. The design of air distribution systems for low-load homes is an integral part of residential system research and development in systems integration. As American homes become more energy efficient, space conditioning systems will be downsized. The downsizing will reach the point where the air flow volumes required to meet the remaining heating and cooling loads may be too small to maintain uniform room air mixing, which can affect thermal comfort. NREL researchers performed a detailed study evaluating the performance of high sidewall supply air jets over a wide range of parameters including supply air temperature, supply air velocity, and supply inlet size. They found that in heating mode, low and intermediate supply temperatures of 95 F (308 K) and 105 F (314 K) maintained acceptable comfort levels at lower fan powers than can be achieved at 120 F (322 K) supply temperatures. For the high supply temperature of 120 F (322 K), higher fan powers (supply velocities) were required to overcome buoyancy effects and reach a good mixing in the room. In cooling mode, a supply temperature of 55 F (286 K) provided acceptable comfort levels. A small supply inlet of 8-in. (0.2 m) x 1-in. (0.025 m) is recommended in both heating and cooling modes. Computational fluid dynamics was used to model heat transfer and airflow in the room

  18. Cold-flow acoustic evaluation of a small scale, divergent, lobed nozzle for supersonic jet noise suppression

    NASA Technical Reports Server (NTRS)

    Huff, R. G.; Groesbeck, D. E.

    1975-01-01

    A supersonic jet noise suppressor was tested with cold flow for acoustic and thrust characteristics at nozzle- to atmospheric-pressure ratios of 1.5 to 4.0. Jet noise suppression and spectral characteristics of the divergent, lobed, suppressor (DLS) nozzle with and without an ejector are presented. Suppression was obtained at nozzle pressure ratios of 2.5 to 4.0. The largest, maximum-lobe, sound pressure level suppression with a hard-wall ejector was 14.6 decibels at a nozzle pressure ratio of 3.5. The thrust loss was 2 percent. In general, low-frequency jet noise was suppressed, leaving higher frequencies essentially unchanged. Without the ejector the nozzle showed a thrust loss of 11 percent together with slightly poorer noise suppression.

  19. Non-auditory factors affecting urban soundscape evaluation.

    PubMed

    Jeon, Jin Yong; Lee, Pyoung Jik; Hong, Joo Young; Cabrera, Densil

    2011-12-01

    The aim of this study is to characterize urban spaces, which combine landscape, acoustics, and lighting, and to investigate people's perceptions of urban soundscapes through quantitative and qualitative analyses. A general questionnaire survey and soundwalk were performed to investigate soundscape perception in urban spaces. Non-auditory factors (visual image, day lighting, and olfactory perceptions), as well as acoustic comfort, were selected as the main contexts that affect soundscape perception, and context preferences and overall impressions were evaluated using an 11-point numerical scale. For qualitative analysis, a semantic differential test was performed in the form of a social survey, and subjects were also asked to describe their impressions during a soundwalk. The results showed that urban soundscapes can be characterized by soundmarks, and soundscape perceptions are dominated by acoustic comfort, visual images, and day lighting, whereas reverberance in urban spaces does not yield consistent preference judgments. It is posited that the subjective evaluation of reverberance can be replaced by physical measurements. The categories extracted from the qualitative analysis revealed that spatial impressions such as openness and density emerged as some of the contexts of soundscape perception.

  20. Evaluation of brainstem function, using acoustic evoked potentials, in 26 patients harbouring a CSF shunt for non-tumoral aqueductal stenosis hydrocephalus.

    PubMed

    Ducati, A; Cenzato, M; Landi, A; Sina, C; Villani, R

    1986-01-01

    26 patients harbouring a CSF shunt for non-tumoral aqueductal stenosis hydrocephalus underwent Brainstem Acoustic Evoked Potentials (BAEPs) recording, to evaluate brainstem function. Only 6 patients presented with normal responses both at standard and at sensitized tests. In the remaining 19 patients, BAEPs were abnormal, bilaterally in 10 cases, monolaterally in 9. Four out of the 6 normal responses belonged to the group recognized of congenital origin. As refers to ventricular size BAEPs were abnormal in 62% of patients with normal ventricle and in 92% of patients with enlarged ventricles. The most significant BAEPs abnormalities were found in patients with maximal ventricular dilation. It appears that BAEPs abnormalities are to the ascribed to both primary and secondary brainstem dysfunction: no reliable criterion to differentiate between these two possibilities is evident. In the individual patient, serial BAEPs recording may contribute to recognize the early phase of supratentorial hypertension due to shunt dysfunction.

  1. Survival of Seaward-Migrating PIT and Acoustic-Tagged Juvenile Chinook Salmon in the Snake and Columbia Rivers: An Evaluation of Length-Specific Tagging Effects

    SciTech Connect

    Brown, Richard S.; Oldenburg, Eric W.; Seaburg, Adam; Cook, Katrina V.; Skalski, John R.; Eppard, M. B.; Deters, Katherine A.

    2013-06-12

    Studies examining the survival of juvenile salmon as they emigrate to the ocean provide important information regarding the management of regulated river systems. Acoustic telemetry is a widely used tool for evaluating the behavior and survival of juvenile salmonids in the Columbia River basin. Thus, it is important to understand how the surgical tagging process and the presence of a transmitter affect survival so any biases can be accounted for or eliminated. This study evaluated the effects of fish length and tag type on the survival of yearling and subyearling Chinook salmon during their seaward migrations through the Snake and Columbia rivers during 2006, 2007, and 2008. Fish were collected at Lower Granite Dam on the Snake River (river kilometer 695) and implanted with either only a passive integrated transponder (PIT) tag (PIT fish) or both a PIT tag and an acoustic transmitter (AT fish). Survival was estimated from release at Lower Granite Dam to multiple downstream locations (dams) using the Cormack–Jolly–Seber single release model, and analysis of variance was used to test for differences among length-classes and between tag types. No length-specific tag effect was detected between PIT and AT fish (i.e., length affected the survival of PIT fish in a manner similar to which it affected the survival of AT fish). Survival among the smallest length class (i.e., 80–89 mm) of both PIT and AT subyearling Chinook salmon was markedly low (i.e., 4%). Fish length was positively correlated with the survival of both PIT and AT fish. Significant differences in survival were detected between tag types; the survival of PIT fish was generally greater than that of AT fish. However, confounding variables warrant caution in making strong inferences regarding this factor. Further, results suggest that tag effects may be due to the process of surgically implanting the transmitter rather than the presence of the transmitter.

  2. Acoustic Tooth Cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1984-01-01

    Acoustically-energized water jet aids in plaque breakdown. Acoustic Wand includes acoustic transducer 1/4 wave plate, and tapered cone. Together elements energize solution of water containing mild abrasive injected into mouth to help prevent calculous buildup.

  3. Acoustic Noise Prediction of the Amine Swingbed ISS ExPRESS Rack Payload

    NASA Technical Reports Server (NTRS)

    Welsh, David; Smith, Holly; Wang, Shuo

    2010-01-01

    Acoustics plays a vital role in maintaining the health, safety, and comfort of crew members aboard the International Space Station (ISS). In order to maintain this livable and workable environment, acoustic requirements have been established to ensure that ISS hardware and payload developers account for the acoustic emissions of their equipment and develop acoustic mitigations as necessary. These requirements are verified by an acoustic emissions test of the integrated hardware. The Amine Swingbed ExPRESS (Expedite the PRocessing of ExperimentS to Space) rack payload creates a unique challenge to the developers in that the payload hardware is transported to the ISS in phases, making an acoustic emissions test on the integrated flight hardware impossible. In addition, the payload incorporates a high back pressure fan and a diaphragm vacuum pump, which are recognized as significant and complex noise sources. In order to accurately predict the acoustic emissions of the integrated payload, the individual acoustic noise sources and paths are first characterized. These characterizations are conducted though a series of acoustic emissions tests on the individual payload components. Secondly, the individual acoustic noise sources and paths are incorporated into a virtual model of the integrated hardware. The virtual model is constructed with the use of hybrid method utilizing the Finite Element Acoustic (FEA) and Statistical Energy Analysis (SEA) techniques, which predict the overall acoustic emissions. Finally, the acoustic model is validated though an acoustic characterization test performed on an acoustically similar mock-up of the flight unit. The results of the validated acoustic model are then used to assess the acoustic emissions of the flight unit and define further acoustic mitigation efforts.

  4. Acoustic engineering at Universidad de las Americas, Ecuador

    NASA Astrophysics Data System (ADS)

    Bravo, Luis A.; Naranjo, Jaime O.; Tassara, Alberto

    2001-05-01

    Acoustics, like science, an instrument to develop new technologies, comfortable atmospheres, and pleasant sounds, has not had a sufficient push in Ecuador. The shortage of professionals in the area, and the social ignorance of the advances and benefits of acoustics have been part of the problem. The University of the Americas has taken the initiative to develop an undergraduate program-only in the country-of sound and acoustics engineering, to contribute to the formation of professional futures that fortify the recent labor market in the areas of audio, professional, and acoustic engineering. This work presents/displays the results of the studies made for the creation of the race, the curricular mesh, and its projections.

  5. 24 CFR 3280.507 - Comfort heat gain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat...

  6. 24 CFR 3280.507 - Comfort heat gain.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat...

  7. 24 CFR 3280.507 - Comfort heat gain.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat...

  8. 24 CFR 3280.507 - Comfort heat gain.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat...

  9. 24 CFR 3280.507 - Comfort heat gain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Comfort heat gain. 3280.507 Section 3280.507 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort...

  10. The End-State Comfort Effect in Young Children

    ERIC Educational Resources Information Center

    Adalbjornsson, Carola F.; Fischman, Mark G.; Rudisill, Mary E.

    2008-01-01

    The end-state comfort effect has been observed in recent studies of grip selection in adults. The present study investigated whether young children also exhibit sensitivity to end-state comfort. The task was to pick up an overturned cup from a table, turn the cup right side up, and pour water into it. Two age groups (N = 20 per group) were…

  11. Passenger ride comfort technology for transport aircraft situations

    NASA Technical Reports Server (NTRS)

    Conner, D. W.; Jacobsen, I. D.

    1976-01-01

    A brief overview is given of NASA research in ride comfort and of the resultant technology. Three useful relations derived from the technology are presented together with five applications of these relations to illustrate their effectiveness in addressing various ride comfort situations of passenger transports.

  12. The Relationship of Empathy to Comforting Behavior Following Film Exposure.

    ERIC Educational Resources Information Center

    Tamborini, Ron; And Others

    1993-01-01

    Investigates differences in comforting behavior that are associated with dimensions of empathy and exposure to film. Finds that fictional involvement and empathic concern were important predictors of comforting behavior and that, after accounting for the influence of these dimensions of empathy, film condition explained further differences in…

  13. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  14. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  15. Using Saliency-Weighted Disparity Statistics for Objective Visual Comfort Assessment of Stereoscopic Images

    NASA Astrophysics Data System (ADS)

    Zhang, Wenlan; Luo, Ting; Jiang, Gangyi; Jiang, Qiuping; Ying, Hongwei; Lu, Jing

    2016-06-01

    Visual comfort assessment (VCA) for stereoscopic images is a particularly significant yet challenging task in 3D quality of experience research field. Although the subjective assessment given by human observers is known as the most reliable way to evaluate the experienced visual discomfort, it is time-consuming and non-systematic. Therefore, it is of great importance to develop objective VCA approaches that can faithfully predict the degree of visual discomfort as human beings do. In this paper, a novel two-stage objective VCA framework is proposed. The main contribution of this study is that the important visual attention mechanism of human visual system is incorporated for visual comfort-aware feature extraction. Specifically, in the first stage, we first construct an adaptive 3D visual saliency detection model to derive saliency map of a stereoscopic image, and then a set of saliency-weighted disparity statistics are computed and combined to form a single feature vector to represent a stereoscopic image in terms of visual comfort. In the second stage, a high dimensional feature vector is fused into a single visual comfort score by performing random forest algorithm. Experimental results on two benchmark databases confirm the superior performance of the proposed approach.

  16. Short-term airing by natural ventilation - implication on IAQ and thermal comfort.

    PubMed

    Heiselberg, P; Perino, M

    2010-04-01

    The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. Among the available ventilation strategies that are currently available, buoyancy driven, single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and Indoor Air Quality (IAQ) control. However, to promote a wider distribution of these systems an improvement in the knowledge of their working principles is necessary. The present study analyses and presents the results of an experimental evaluation of airing performance in terms of ventilation characteristics, IAQ and thermal comfort. It includes investigations of the consequences of opening time, opening frequency, opening area and expected airflow rate, ventilation efficiency, thermal comfort and dynamic temperature conditions. A suitable laboratory test rig was developed to perform extensive experimental analyses of the phenomenon under controlled and repeatable conditions. The results showed that short-term window airing is very effective and can provide both acceptable IAQ and thermal comfort conditions in buildings. Practical Implications This study gives the necessary background and in-depth knowledge of the performance of window airing by single-sided natural ventilation necessary for the development of control strategies for window airing (length of opening period and opening frequency) for optimum IAQ and thermal comfort in naturally ventilated buildings.

  17. Validation of the Comfort scale for relatives of people in critical states of health 1

    PubMed Central

    Freitas, Kátia Santana; Menezes, Igor Gomes; Mussi, Fernanda Carneiro

    2015-01-01

    Abstract Objective: this methodological study aims to present the construct validity of the Comfort scale for family members of people in a critical state of health (ECONF). Method: this is a methodological study. The sample was made up of 274 family members of adults receiving inpatient treatment in six Intensive Care Units (ICU) in the State of Bahía responded to 62 items distributed in 7 dimensions. The validation procedures adopted were based on the techniques of the Classical Test Theory. Results: the analysis of dimensionality was undertaken through principal components analysis, a scale being obtained with 55 items distributed in four factors: Safety, Support, Family member-relative interaction and Integration with oneself and the everyday. The analysis of the items' , discriminative power, undertaken by the item-total correlation-coefficient showed a good relationship of the items with their respective factors. From the ECONF's reliability test, from the analysis of internal consistency, a raised Alpha Cronbach coefficient was obtained for the 4 factors and the general measurement. Conclusion: the comfort scale presented satisfactory psychometric parameters, thus constituting the first valid instrument for evaluating the comfort of family members of people in a critical state of health. The advance made by the study lies in its theoretical framework on comfort, and provides the health team with a scale based on empirical evidence. PMID:26444168

  18. Analysis of human thermal comfort and its tendencies in Budapest (Hungary)

    NASA Astrophysics Data System (ADS)

    Nemeth, Akos; Kovacs, Attila

    2013-04-01

    In spite of the fact that the evaluation of the thermal conditions in the urban areas is extremely important and timely, in Budapest (capital of Hungary) very few studies were performed in this direction until now. The aim of this paper is to analyze the differences and changes of the thermal comfort conditions in the last half century (1961-2010) by comparing measurements of two meteorological stations located in different environments of Budapest: one in the central urban area (Local Climate Zone 2 - 'compact midrise') and the other in the suburbs (between Local Climate Zones 6 - 'open lowrise' and A - 'dense trees'). The thermal comfort was characterized by two human bioclimatological comfort indices, the Physiologically Equivalent Temperature (PET) and the Universal Thermal Climate Index (UTCI), for four characteristic times of the day in the examined period. Then the thermal comfort differences between the stations according to two climatic normal periods (1961-1990 and 1981-2010), and the tendencies detected among the periods were also under investigation. For the last decade, 2001-2010, hourly-resolution investigations were carried out. The results indicate that the central area is affected by a higher degree of hot stress and less cold stress. Additionally, the warm stress has become more frequent, however, the cold heat load decreased in both examined area at each time.

  19. Experimental verification of transient nonlinear acoustical holography.

    PubMed

    Jing, Yun; Cannata, Jonathan; Wang, Tianren

    2013-05-01

    This paper presents an experimental study on nonlinear transient acoustical holography. The validity and effectiveness of a recently proposed nonlinear transient acoustical holography algorithm is evaluated in the presence of noise. The acoustic field measured on a post-focal plane of a high-intensity focused transducer is backward projected to reconstruct the pressure distributions on the focal and a pre-focal plane, which are shown to be in good agreement with the measurement. In contrast, the conventional linear holography produces erroneous results in this case where the nonlinearity involved is strong. Forward acoustic field projection was also carried out to further verify the algorithm. PMID:23654362

  20. Experimental verification of transient nonlinear acoustical holography.

    PubMed

    Jing, Yun; Cannata, Jonathan; Wang, Tianren

    2013-05-01

    This paper presents an experimental study on nonlinear transient acoustical holography. The validity and effectiveness of a recently proposed nonlinear transient acoustical holography algorithm is evaluated in the presence of noise. The acoustic field measured on a post-focal plane of a high-intensity focused transducer is backward projected to reconstruct the pressure distributions on the focal and a pre-focal plane, which are shown to be in good agreement with the measurement. In contrast, the conventional linear holography produces erroneous results in this case where the nonlinearity involved is strong. Forward acoustic field projection was also carried out to further verify the algorithm.

  1. 33 CFR 165.809 - Security Zones; Port of Port Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zones; Port of Port Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi Inner Harbor, Corpus Christi, TX. 165... Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi Inner Harbor, Corpus Christi, TX....

  2. Highly sensitive monitoring of chest wall dynamics and acoustics provides diverse valuable information for evaluating ventilation and diagnosing pneumothorax.

    PubMed

    Pesin, Jimy; Faingersh, Anna; Waisman, Dan; Landesberg, Amir

    2014-06-15

    Current practice of monitoring lung ventilation in neonatal intensive care units, utilizing endotracheal tube pressure and flow, end-tidal CO2, arterial O2 saturation from pulse oximetry, and hemodynamic indexes, fails to account for asymmetric pathologies and to allow for early detection of deteriorating ventilation. This study investigated the utility of bilateral measurements of chest wall dynamics and sounds, in providing early detection of changes in the mechanics and distribution of lung ventilation. Nine healthy New Zealand rabbits were ventilated at a constant pressure, while miniature accelerometers were attached to each side of the chest. Slowly progressing pneumothorax was induced by injecting 1 ml/min air into the pleural space on either side of the chest. The end of the experiment (tPTX) was defined when arterial O2 saturation from pulse oximetry dropped <90% or when vigorous spontaneous breathing began, since it represents the time of clinical detection using common methods. Consistent and significant changes were observed in 15 of the chest dynamics parameters. The most meaningful temporal changes were noted for features extracted from subsonic dynamics (<10 Hz), e.g., tidal amplitude, energy, and autoregressive poles. Features from the high-frequency band (10-200 Hz), e.g., energy and entropy, exhibited smaller but significant changes. At 70% tPTX, identification of asymmetric ventilation was attained for all animals. Side identification of the pneumothorax was achieved at 50% tPTX, within a 95% confidence interval. Diagnosis was, on average, 34.1 ± 18.8 min before tPTX. In conclusion, bilateral monitoring of the chest dynamics and acoustics provide novel information that is sensitive to asymmetric changes in ventilation, enabling early detection and localization of pneumothorax. PMID:24790013

  3. Highly sensitive monitoring of chest wall dynamics and acoustics provides diverse valuable information for evaluating ventilation and diagnosing pneumothorax.

    PubMed

    Pesin, Jimy; Faingersh, Anna; Waisman, Dan; Landesberg, Amir

    2014-06-15

    Current practice of monitoring lung ventilation in neonatal intensive care units, utilizing endotracheal tube pressure and flow, end-tidal CO2, arterial O2 saturation from pulse oximetry, and hemodynamic indexes, fails to account for asymmetric pathologies and to allow for early detection of deteriorating ventilation. This study investigated the utility of bilateral measurements of chest wall dynamics and sounds, in providing early detection of changes in the mechanics and distribution of lung ventilation. Nine healthy New Zealand rabbits were ventilated at a constant pressure, while miniature accelerometers were attached to each side of the chest. Slowly progressing pneumothorax was induced by injecting 1 ml/min air into the pleural space on either side of the chest. The end of the experiment (tPTX) was defined when arterial O2 saturation from pulse oximetry dropped <90% or when vigorous spontaneous breathing began, since it represents the time of clinical detection using common methods. Consistent and significant changes were observed in 15 of the chest dynamics parameters. The most meaningful temporal changes were noted for features extracted from subsonic dynamics (<10 Hz), e.g., tidal amplitude, energy, and autoregressive poles. Features from the high-frequency band (10-200 Hz), e.g., energy and entropy, exhibited smaller but significant changes. At 70% tPTX, identification of asymmetric ventilation was attained for all animals. Side identification of the pneumothorax was achieved at 50% tPTX, within a 95% confidence interval. Diagnosis was, on average, 34.1 ± 18.8 min before tPTX. In conclusion, bilateral monitoring of the chest dynamics and acoustics provide novel information that is sensitive to asymmetric changes in ventilation, enabling early detection and localization of pneumothorax.

  4. Noise and vibration ride comfort criteria

    NASA Technical Reports Server (NTRS)

    Dempsey, T. K.; Leatherwood, J. D.; Clevenson, S. A.

    1976-01-01

    A program is underway at Langley Research Center to develop a comprehensive ride quality model based upon the various physical and psychological factors that most affect passenger ride comfort. Two of the most important factors, namely, vibration and noise were studied to (1) determine whether composite or separate noise and vibration criteria are needed for the prediction of ride quality, (2) determine a noise correction for the previously-defined vibration criteria of the ride quality model, (3) assess whether these noise corrections depend on the nature of the vibration stimuli, i.e., deterministic as opposed to random, and (4) specify noise-vibration criteria for this combined environment. The stimuli for the study consisted of octave bands of noise centered at 500 or 2000 Hz and vertical vibrations composed of either 5 Hz sinusoidal vibration or random vibrations centered at 5 Hz and with a 5 Hz bandwidth. The noise stimuli were presented at levels ranging from ambient to 95 dB(A) and the vibrations at levels ranging from 0.02 to 0.13 g-rms.

  5. Acoustic emission descriptors

    NASA Astrophysics Data System (ADS)

    Witos, Franciszek; Malecki, Ignacy

    The authors present selected problems associated with acoustic emission interpreted as a physical phenomenon and as a measurement technique. The authors examine point sources of acoustic emission in isotropic, homogeneous linearly elastic media of different shapes. In the case of an unbounded medium the authors give the analytical form of the stress field and the wave shift field of the acoustic emission. In the case of a medium which is unbounded plate the authors give a form for the equations which is suitable for numerical calculation of the changes over time of selected acoustic emission values. For acoustic emission as a measurement technique, the authors represent the output signal as the resultant of a mechanical input value which describes the source, the transient function of the medium, and the transient function of specific components of the measurement loop. As an effect of this notation, the authors introduce the distinction between an acoustic measurement signal and an acoustic measurement impulse. The authors define the basic parameters of an arbitrary impulse. The authors extensively discuss the signal functions of acoustic emission impulses and acoustic emission signals defined in this article as acoustic emission descriptors (or signal functions of acoustic emission impulses) and advanced acoustic emission descriptors (which are either descriptors associated with acoustic emission applications or the signal functions of acoustic emission signals). The article also contains the results of experimental research on three different problems in which acoustic emission descriptors associated with acoustic emission pulses, acoustic emission applications, and acoustic emission signals are used. These problems are respectively: a problem of the amplitude-load characteristics of acoustic emission pulses in carbon samples subjected to compound uniaxial compression, the use of acoustic emission to predict the durability characteristics of conveyor belts, and

  6. Comparisons among aerodynamic, electroglottographic, and acoustic spectral measures of female voice.

    PubMed

    Holmberg, E B; Hillman, R E; Perkell, J S; Guiod, P C; Goldman, S L

    1995-12-01

    This study examines measures of the glottal airflow waveform, the electroglottographic signal (EGG), amplitude differences between peaks in the acoustic spectrum, and observations of the spectral energy content of the third formant (F3), in terms of how they relate to one another. Twenty females with normal voices served as subjects. Both group and individual data were studied. Measurements were made for the vowel in two speech tasks: strings of the syllable /pae/and sustained phonation of /ae/, which were produced at two levels of vocal effort: comfortable and loud voice. The main results were: 1. Significant differences in parameter values between /pae/and/ae/were related to significant differences in the sound pressure level (SPL). 2. An "adduction quotient," measured from the glottal waveform at a 30% criterion, was sensitive enough to differentiate between waveforms reflecting abrupt versus gradual vocal fold closing movements. 3. DC flow showed weak or nonsignificant relationships with acoustic measures. 4. The spectral content in the third formant (F3) in comfortable loudness typically consisted of a mix of noise and harmonic energy. In loud voice, the F3 spectral content typically consisted of harmonic energy. 5. Significant differences were found in all measures between tokens with F3 harmonic energy and tokens with F3 noise, independent of loudness condition. 6. Strong relationships between flow- and EGG-adduction quotients suggested that these signals can be used to complement each other. 7. The amplitude difference between spectral peaks of the first and third formant (F1-F3) was found to add information about abruptness of airflow decrease (flow declination) that may be lost in the glottal waveform signal due to low-pass filtering. The results are discussed in terms of how an integrated use of these measures can contribute to a better understanding of the normal vocal mechanism and help to improve methods for evaluating vocal function. PMID:8747815

  7. Vocal projection in actors: the long-term average spectral features that distinguish comfortable acting voice from voicing with maximal projection in male actors.

    PubMed

    Pinczower, Rachel; Oates, Jennifer

    2005-09-01

    This study explored whether acoustic and perceptual features could distinguish comfortable from maximally projected acting voice. Thirteen professional male actors performed a passage from William Shakespeare's Julius Caesar twice. The first delivery used their comfortably projected voices, whereas the second used maximal projection. Acoustic measures, expert ratings, and self-ratings of projection and voice quality were investigated. Long-term average spectra (LTAS) and sound pressure level (SPL) analyses were conducted. Perceptual variables included projection, breathiness, roughness, and strain. When comparing the intensity difference between the higher (2-4 kHz) and lower (0-2 kHz) regions of the spectrum in voice samples from the maximal projected condition, LTAS analyses demonstrated increased acoustic energy in the higher part of the spectrum. This LTAS pattern was not as evident in the comfortable projected condition. These findings offered some preliminary support for the existence of an actor's formant (prominent peak in the upper part of the spectrum) during maximal projection. PMID:16102670

  8. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  9. Acoustic cryocooler

    DOEpatents

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

    An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

  10. Acoustic telemetry.

    SciTech Connect

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  11. Home studio acoustic treatments on a budget

    NASA Astrophysics Data System (ADS)

    Haverstick, Gavin A.

    2003-04-01

    Digital technology in the recording industry has evolved and expanded, allowing it to be widely available to the public at a significantly lower cost than in previous years. Due to this fact, numerous home studios are either being built inside or converted from bedrooms, dens, and basements. Hobbyists and part-time musicians that typically do not have the advantage of a large recording budget operate the majority of these home studios. Along with digital equipment, acoustic treatment has become more affordable over the years giving many musicians the ability to write, record, and produce an entire album in the comfort of their own home without having to sacrifice acoustical quality along the way. Three separate case studies were conducted on rooms with various sizes, applications, and budgets. Acoustical treatment such as absorption, diffusion, and bass trapping were implemented to reduce the effects of issues such as flutter echo, excessive reverberation, and bass build-up among others. Reactions and subjective comments from each individual studio owner were gathered and assessed to determine how effective home studios can be on a personal and professional level if accurately treated acoustically.

  12. An evaluation of acoustic seabed classification techniques for marine biotope monitoring over broad-scales (>1 km 2) and meso-scales (10 m 2-1 km 2)

    NASA Astrophysics Data System (ADS)

    van Rein, H.; Brown, C. J.; Quinn, R.; Breen, J.; Schoeman, D.

    2011-07-01

    Acoustic seabed classification is a useful tool for monitoring marine benthic habitats over broad-scales (>1 km 2) and meso-scales (10 m 2-1 km 2). Its utility in this context was evaluated using two approaches: by describing natural changes in the temporal distribution of marine biotopes across the broad-scale (4 km 2), and by attempting to detect specific experimentally-induced changes to kelp-dominated biotopes across the meso-scale (100 m 2). For the first approach, acoustic backscatter mosaics were constructed using sidescan sonar and multibeam echosounder data collected from Church Bay (Rathlin Island, Northern Ireland) in 1999, 2008 and 2009. The mosaics were manually segmented into acoustic facies, which were ground-truthed using a drop-video camera. Biotopes were classified from the video by multivariate exploratory analysis and cross-tabulated with the acoustic facies, showing a positive correlation. These results were integrated with bathymetric data to map the distribution of seven unique biotopes in Church Bay. Kappa analysis showed the biotope distribution was highly similar between the biotope maps, possibly due to the stability of bedforms shaped by the tidal regime around Rathlin Island. The greatest biotope change in this approach was represented by seasonal and annual changes in the growth of the seagrass, Zostera marina. In the second approach, sidescan sonar data were collected before and after the removal of 100 m 2 of kelp from three sites. Comparison of the data revealed no differences between the high-resolution backscatter imagery. It is concluded that acoustic seabed classification can be used to monitor change over broad- and meso-scales but not necessarily for all biotopes; its success depends on the type of acoustic system employed and the biological characteristics of the target biotope.

  13. Design and evaluation of a higher-order spherical microphone/ambisonic sound reproduction system for the acoustical assessment of concert halls

    NASA Astrophysics Data System (ADS)

    Clapp, Samuel W.

    Previous studies of the perception of concert hall acoustics have generally employed two methods for soliciting listeners' judgments. One method is to have listeners rate the sound in a hall while physically present in that hall. The other method is to make recordings of different halls and seat positions, and then recreate the environment for listeners in a laboratory setting via loudspeakers or headphones. In situ evaluations offer a completely faithful rendering of all aspects of the concert hall experience. However, many variables cannot be controlled and the short duration of auditory memory precludes an objective comparison of different spaces. Simulation studies allow for more control over various aspects of the evaluations, as well as A/B comparisons of different halls and seat positions. The drawback is that all simulation methods suffer from limitations in the accuracy of reproduction. If the accuracy of the simulation system is improved, then the advantages of the simulation method can be retained, while mitigating its disadvantages. Spherical microphone array technology has received growing interest in the acoustics community in recent years for many applications including beamforming, source localization, and other forms of three-dimensional sound field analysis. These arrays can decompose a measured sound field into its spherical harmonic components, the spherical harmonics being a set of spatial basis functions on the sphere that are derived from solving the wave equation in spherical coordinates. Ambisonics is a system for two- and three-dimensional spatialized sound that is based on recreating a sound field from its spherical harmonic components. Because of these shared mathematical underpinnings, ambisonics provides a natural way to present fully spatialized renderings of recordings made with a spherical microphone array. Many of the previously studied applications of spherical microphone arrays have used a narrow frequency range where the array

  14. National Television of Chile--New headquarters building acoustic projects

    NASA Astrophysics Data System (ADS)

    Huaquin, Mario

    2002-11-01

    In the last 15 years TV stations in Chile have been incorporating in their facilities architectural acoustic and noise control approaches. This has been necessary as much for the technological advance, as for the necessity to achieve a better quality of sound that the listeners receive. In 1998, the National Television of Chile, with the sponsorship of the College of Architects of Chile, requested preliminary architectural designs in order to enlarge and to renovate its headquarters buildings in Santiago, Chile in stages. The Acoustic Project has been developed in an integral way, with three fundamental disciplines: noise and noise control; Machine rooms; vibrations and vibration control; Buildings, engines; architectural acoustics and acoustic comfort; TV studios and technical rooms. This presentation describes the Acoustic Project, phases I (1999), and II (2002), how it was possible to establish a common language with architects and engineers and the different specialties, to apply acoustic criteria and standards, the theoretical development and the projected acoustic solutions. (To be presented in Spanish.)

  15. A real challenge: Teaching acoustics to architecture students

    NASA Astrophysics Data System (ADS)

    Raichel, Daniel R.

    2003-04-01

    The key to instilling the fundamentals of acoustics in architecture students is to arouse their interest. Because so many of the students are interested in music and high-fidelity equipment, it does not take much to ignite their interest in acoustics, particularly when they come to realize that perfectly good equipment can be undermined by poor room acoustics. Because they generally are not comfortable with mathematics, having had received perhaps no more than one or two semesters of introductory calculus; they need to be spoon-fed mathematics, even to the point of reviewing logarithmic manipulations, which are normally taught in secondary schools. The purpose of teaching acoustics to architects is not to make them acoustic experts, per se, but to make them appreciative of the effect of room acoustics and to understand that they must work hand-in-hand with acousticians when they design listening spaces that range in size from small classrooms to lecture halls to large concert halls. A regular acoustics text, such as that by Beranek, or Kinsler and Frey, or Raichel would be beyond the scope of an architectural course, but a text written especially for nonscience majors (such as that by Apfel) should and did serve admirably.

  16. Visual Comfort Analysis of Innovative Interior and Exterior Shading Systems for Commercial Buildings using High Resolution Luminance Images

    SciTech Connect

    Konis, Kyle; Lee, Eleanor; Clear, Robert

    2011-01-11

    The objective of this study was to explore how calibrated high dynamic range (HDR) images (luminance maps) acquired in real world daylit environments can be used to characterize, evaluate, and compare visual comfort conditions of innovative facade shading and light-redirecting systems. Detailed (1536 x 1536 pixel) luminance maps were time-lapse acquired from two view positions in an unoccupied full scale testbed facility. These maps were analyzed using existing visual comfort metrics to quantify how innovative interior and exterior shading systems compare to conventional systems under real sun and sky conditions over a solstice-to-solstice test interval. The results provide a case study in the challenges and potential of methods of visualizing, evaluating and summarizing daily and seasonal variation of visual comfort conditions computed from large sets of image data.

  17. Numerical predictions in acoustics

    NASA Technical Reports Server (NTRS)

    Hardin, Jay C.

    1992-01-01

    Computational Aeroacoustics (CAA) involves the calculation of the sound produced by a flow as well as the underlying flowfield itself from first principles. This paper describes the numerical challenges of CAA and recent research efforts to overcome these challenges. In addition, it includes the benefits of CAA in removing restrictions of linearity, single frequency, constant parameters, low Mach numbers, etc. found in standard acoustic analyses as well as means for evaluating the validity of these numerical approaches. Finally, numerous applications of CAA to both classical as well as modern problems of concern to the aerospace industry are presented.

  18. Numerical predictions in acoustics

    NASA Astrophysics Data System (ADS)

    Hardin, Jay C.

    Computational Aeroacoustics (CAA) involves the calculation of the sound produced by a flow as well as the underlying flowfield itself from first principles. This paper describes the numerical challenges of CAA and recent research efforts to overcome these challenges. In addition, it includes the benefits of CAA in removing restrictions of linearity, single frequency, constant parameters, low Mach numbers, etc. found in standard acoustic analyses as well as means for evaluating the validity of these numerical approaches. Finally, numerous applications of CAA to both classical as well as modern problems of concern to the aerospace industry are presented.

  19. Nurses' fear of death and comfort level with dying patients.

    PubMed

    Hare, J; Pratt, C C

    1989-01-01

    This study examined differences in nurses' fear of death and level of comfort with patients having a poor prognosis for survival, as a function of the nurses' occupational level, work setting, and level of exposure to such patients. In addition, the relationship among the multidimensional aspects of fear of death and level of comfort with patients' poor prognosis was assessed. The sample included 312 professional and paraprofessional nurses who worked in hospitals and nursing homes. Level of comfort with working with dying patients was found to differ significantly by exposure to such patients and by occupational role. Fear of death for significant others was found to differ significantly by work setting. Finally, a significant inverse relationship was found between comfort working with dying patients and overall fear of death. Suggestions for future research are presented.

  20. 67. Smart view recreation area comfort station, reflecting Appalachian Architecture, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. Smart view recreation area comfort station, reflecting Appalachian Architecture, was completed by the summer of 1940 by era crews. View to the south-southeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  1. Thermal comfort of patients in hospital ward areas.

    PubMed Central

    Smith, R. M.; Rae, A.

    1977-01-01

    The patient is identified as being of prime importance for comfort standards in hospital ward areas, other ward users being expected to adjust their dress to suit the conditions necessary for patients comfort. A study to identify the optimum steady state conditions for patients comfort is then described. Although this study raises some doubts as to the applicability of the standard thermal comfort assessment techniques to ward areas, it is felt that its results give a good indication of the steady-state conditions preferred by the patients. These were an air temperature of between 21-5 degrees and 22 degrees C and a relative humidity of between 30% and 70%, where the air velocity was less than 0-1 m/s and the mean radiant temperature was close to air temperature. PMID:264497

  2. Thermal Comfort in the Hot Humid Tropics of Australia

    PubMed Central

    Wyndham, C. H.

    1963-01-01

    Day and night comfort votes were recorded from Caucasian residents at Weipa, a mission station in the hot humid tropics of North Queensland, Australia. The limit of day comfort for more than 50% of the men was 81·5°F. (27·5°C.) “normal” corrected effective temperature; the night limit was 78·0°F. (25·5°C.). Day comfort limits correlated well with air conditions at which sweat was apparent: night limits correlated with the amount of bed covering. Evidence of a change over 14 days in day comfort limit was found. Limitations in the effective temperature scale for expressing the “oppressive nature” of night air conditions are pointed out. Criticism is voiced of the use of dry bulb temperature instead of the effective temperature scale in conditions of high wet bulb temperatures with high relative humidity, such as in the hot humid tropics. PMID:14002126

  3. 68. Smart view recreation area comfort station with postandrail fence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    68. Smart view recreation area comfort station with post-and-rail fence reflecting Appalachian culture. Facing west. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  4. Acoustical Modifications for the Classroom.

    ERIC Educational Resources Information Center

    Crandell, Carl C.; Smaldino, Joseph J.

    1999-01-01

    This article reviews procedures for evaluating, measuring, and modifying noise and reverberation levels in the classroom environment. Recommendations include: relocating children away from high noise sources, such as fans, air conditioners, heating ducts, and faulty lighting fixtures, using sound-absorbing materials, using acoustical ceiling tile…

  5. From occupying to inhabiting - a change in conceptualising comfort

    NASA Astrophysics Data System (ADS)

    Jaffari, Svenja D.; Matthews, Ben

    2009-11-01

    The concept of 'comfort' has been influential in shaping aspects of our built environment. For the construction industry, comfort is predominantly understood in terms of the balance between an ideal human physiological state and a finite number of measurable environmental parameters that can be controlled (temperature, humidity, air quality, daylighting, noise). It is such a notion of comfort that has informed the establishment of universally applied comfort standards and guidelines for the built environment. When buildings rigidly conform to these standards, they consume vast quantities of energy and are responsible for higher levels of GHG emissions. Recent researchers have challenged such instrumental definitions of comfort on moral and environmental grounds. In this paper, we address this issue from two different standpoints: one empirical, one related to the design of technology. Empirically, we present an analysis of ethnographic field material that has examined how, in what circumstances, and at what times ordinary users employ energy-intensive indoor climate technologies in their daily lives. We argue that when comfort is viewed as an achievement, rather than as a reified and static ideal homeostasis between humans and their environmental conditions, it becomes easier to appreciate the extent to which comfort is, for ordinary people, personally idiosyncratic, culturally relative, socially influenced and highly dependent on temporality, sequence and activity. With respect to design, we introduce a set of provocative designed prototypes that embody alternative conceptions of 'comfort' than those to which the building industry typically subscribes. Our discussion has critical implications for the types of technologies that result from a 'comfort standards' conception. Firstly, we show that comfort is not simply a homeostatic equilibrium-such a view is overly narrow, inflexible and ultimately an inaccurate conception of what comfort is for ordinary people

  6. ACOUSTIC LINERS FOR TURBOFAN ENGINES

    NASA Technical Reports Server (NTRS)

    Minner, G. L.

    1994-01-01

    This program was developed to design acoustic liners for turbofan engines. This program combines results from theoretical models of wave alternation in acoustically treated passages with experimental data from full-scale fan noise suppressors. By including experimentally obtained information, the program accounts for real effects such as wall boundary layers, duct terminations, and sound modal structure. The program has its greatest use in generating a number of design specifications to be used for evaluation of trade-offs. The program combines theoretical and empirical data in designing annular acoustic liners. First an estimate of the noise output of the fan is made based on basic fan aerodynamic design variables. Then, using a target noise spectrum after alternation and the estimated fan noise spectrum, a design spectrum is calculated as their difference. Next, the design spectrum is combined with knowledge of acoustic liner performance and the liner design variables to specify the acoustic design. Details of the liner design are calculated by combining the required acoustic impedance with a mathematical model relating acoustic impedance to the physical structure of the liner. Input to the noise prediction part of the program consists of basic fan operating parameters, distance that the target spectrum is to be measured and the target spectrum. The liner design portion of the program requires the required alternation spectrum, desired values of length to height and several option selection parameters. Output from the noise prediction portion is a noise spectrum consisting of discrete tones and broadband noise. This may be used as input to the liner design portion of the program. The liner design portion of the program produces backing depths, open area ratios, and face plate thicknesses. This program is written in FORTRAN V and has been implemented in batch mode on a UNIVAC 1100 series computer with a central memory requirement of 12K (decimal) of 36 bit words.

  7. Creating high performance buildings: Lower energy, better comfort

    NASA Astrophysics Data System (ADS)

    Brager, Gail; Arens, Edward

    2015-03-01

    Buildings play a critical role in the challenge of mitigating and adapting to climate change. It is estimated that buildings contribute 39% of the total U.S. greenhouse gas (GHG) emissions [1] primarily due to their operational energy use, and about 80% of this building energy use is for heating, cooling, ventilating, and lighting. An important premise of this paper is about the connection between energy and comfort. They are inseparable when one talks about high performance buildings. Worldwide data suggests that we are significantly overcooling buildings in the summer, resulting in increased energy use and problems with thermal comfort. In contrast, in naturally ventilated buildings without mechanical cooling, people are comfortable in much warmer temperatures due to shifting expectations and preferences as a result of occupants having a greater degree of personal control over their thermal environment; they have also become more accustomed to variable conditions that closely reflect the natural rhythms of outdoor climate patterns. This has resulted in an adaptive comfort zone that offers significant potential for encouraging naturally ventilated buildings to improve both energy use and comfort. Research on other forms for providing individualized control through low-energy personal comfort systems (desktop fans, foot warmed, and heated and cooled chairs) have also demonstrated enormous potential for improving both energy and comfort performance. Studies have demonstrated high levels of comfort with these systems while ambient temperatures ranged from 64-84°F. Energy and indoor environmental quality are inextricably linked, and must both be important goals of a high performance building.

  8. Creating high performance buildings: Lower energy, better comfort

    SciTech Connect

    Brager, Gail; Arens, Edward

    2015-03-30

    Buildings play a critical role in the challenge of mitigating and adapting to climate change. It is estimated that buildings contribute 39% of the total U.S. greenhouse gas (GHG) emissions [1] primarily due to their operational energy use, and about 80% of this building energy use is for heating, cooling, ventilating, and lighting. An important premise of this paper is about the connection between energy and comfort. They are inseparable when one talks about high performance buildings. Worldwide data suggests that we are significantly overcooling buildings in the summer, resulting in increased energy use and problems with thermal comfort. In contrast, in naturally ventilated buildings without mechanical cooling, people are comfortable in much warmer temperatures due to shifting expectations and preferences as a result of occupants having a greater degree of personal control over their thermal environment; they have also become more accustomed to variable conditions that closely reflect the natural rhythms of outdoor climate patterns. This has resulted in an adaptive comfort zone that offers significant potential for encouraging naturally ventilated buildings to improve both energy use and comfort. Research on other forms for providing individualized control through low-energy personal comfort systems (desktop fans, foot warmed, and heated and cooled chairs) have also demonstrated enormous potential for improving both energy and comfort performance. Studies have demonstrated high levels of comfort with these systems while ambient temperatures ranged from 64–84°F. Energy and indoor environmental quality are inextricably linked, and must both be important goals of a high performance building.

  9. Acoustic hemostasis

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence; Beach, Kirk; Carter, Stephen; Chandler, Wayne; Curra, Francesco; Kaczkowski, Peter; Keilman, George; Khokhlova, Vera; Martin, Roy; Mourad, Pierre; Vaezy, Shahram

    2000-07-01

    In cases of severe injury, physicians speak of a "golden hour"—a brief grace period in which quickly applied, proper therapy can save the life of the patient. Much of this mortality results from exsanguination, i.e., bleeding to death—often from internal hemorrhage. The inability of a paramedic to treat breaches in the vascular system deep within the body or to stem the loss of blood from internal organs is a major reason for the high level of mortality associated with blunt trauma. We have undertaken an extensive research program to treat the problem of internal bleeding. Our approach is as follows: (a) We use scanning ultrasound to identify internal bleeding and hemorrhage, (b) we use ultrasound imaging to locate specific breaches in the vascular system, both from damaged vessels and gross damage to the capillary bed, and (c) we use High Intensity Focused Ultrasound (HIFU) to treat the damaged region and to induce hemostasis. We present a general review of this research with some emphasis on the role of nonlinear acoustics.

  10. The acoustics of snoring.

    PubMed

    Pevernagie, Dirk; Aarts, Ronald M; De Meyer, Micheline

    2010-04-01

    Snoring is a prevalent disorder affecting 20-40% of the general population. The mechanism of snoring is vibration of anatomical structures in the pharyngeal airway. Flutter of the soft palate accounts for the harsh aspect of the snoring sound. Natural or drug-induced sleep is required for its appearance. Snoring is subject to many influences such as body position, sleep stage, route of breathing and the presence or absence of sleep-disordered breathing. Its presentation may be variable within or between nights. While snoring is generally perceived as a social nuisance, rating of its noisiness is subjective and, therefore, inconsistent. Objective assessment of snoring is important to evaluate the effect of treatment interventions. Moreover, snoring carries information relating to the site and degree of obstruction of the upper airway. If evidence for monolevel snoring at the site of the soft palate is provided, the patient may benefit from palatal surgery. These considerations have inspired researchers to scrutinize the acoustic characteristics of snoring events. Similarly to speech, snoring is produced in the vocal tract. Because of this analogy, existing techniques for speech analysis have been applied to evaluate snoring sounds. It appears that the pitch of the snoring sound is in the low-frequency range (<500 Hz) and corresponds to a fundamental frequency with associated harmonics. The pitch of snoring is determined by vibration of the soft palate, while nonpalatal snoring is more 'noise-like', and has scattered energy content in the higher spectral sub-bands (>500 Hz). To evaluate acoustic properties of snoring, sleep nasendoscopy is often performed. Recent evidence suggests that the acoustic quality of snoring is markedly different in drug-induced sleep as compared with natural sleep. Most often, palatal surgery alters sound characteristics of snoring, but is no cure for this disorder. It is uncertain whether the perceived improvement after palatal surgery, as

  11. Simple, all-optical, noncontact, depth-selective, narrowband surface acoustic wave measurement system for evaluating the Rayleigh velocity of small samples or areas.

    PubMed

    Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun

    2009-03-10

    In this paper a new ultrasonic testing system is described that utilizes noncontact optical methods to generate and detect surface acoustic waves (SAWs) and has significant applications in the nondestructive evaluation of surface material. A narrowband SAW is generated with a new and straightforward grating mask image projection method that provides fast switching and a controllable frequency band, and hence control of the penetration depth of the ultrasonic wave. A narrowband SAW with center frequency above 30 MHz, and hence better depth resolution, is generated. The detection of the SAW is performed with a simplified design of an optical fiber interferometer that has good sensitivity and manoeuvrability without requiring additional auxiliary components. The novel combination of these two optical techniques permits the measurement of small samples that are otherwise difficult to measure, especially nondestructively. A model was constructed to simulate the temporal characteristics of the generated narrowband SAW and showed good agreement with experiment. Measurements on an aluminum sample and an extracted human incisor demonstrate the system's performance. PMID:19277076

  12. Evaluation of suspended sediment concentrations, sediment fluxes and sediment depositions along a reservoir by using laser diffraction and acoustic backscatter data

    NASA Astrophysics Data System (ADS)

    Lizano, Laura; Haun, Stefan

    2015-04-01

    The construction of dams and reservoirs disturb the natural morphological behavior of rivers. A natural settling effect occurs due to the reduced turbulences and flow velocities. As a consequence, reservoirs fill up with sediments which results in a reduction of storage volume, influences the operation of hydropower plants and leads in several cases to flood protection problems. The sediment depositions in reservoirs are standardly evaluated by using bathymetric data, obtained by a single beam sonar from pre-defined cross sections or by an extensive evaluation of the reservoir bed by a side scan sonar. However, a disadvantage of this method is that it is not possible to evaluate the pore water content of the depositions, which may lead as consequence to an uncertainty in the measured amount of deposited sediments. Given that a major part of sediments entering reservoirs are transported in suspension, sediment flux measurements along defined transects could give more reliable information on the settled amount of sediments and additional information on the sediment transport mechanism within the reservoir. An evaluation of the sediment fluxes is in practice often conducted by a single suspended sediment concentration (SSC) measurement in combination with a cross sectional calibration factor to take changes in the SSC along the transect into account. However, these calibration factors are often developed only for one specific in-situ condition and may give unreliable results in case that the boundaries change e.g. the hydraulic conditions. Hence an evaluation of the sediment fluxes along the whole transect would give a more reliable number for the amount of transported sediments through the reservoir. This information can afterwards be used to calculate the amount of settled sediments in different sections of the reservoir and the amount of sediments which will enter the intake. For this study the suspended sediment transport within the Peñas Blancas reservoir in

  13. Baffling or Baffled: Improve Your Acoustics.

    ERIC Educational Resources Information Center

    Abdoo, Frank B.

    1981-01-01

    Presents techniques for evaluating the acoustics (reverberation time, and standing waves and resonance phenomena) of a band performance room. Gives instructions for building and placing inexpensive baffles (free-standing, portable sound barriers) to correct room defects. (SJL)

  14. Acoustic source for generating an acoustic beam

    DOEpatents

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  15. Effectiveness of traditional climatic responses in the central Texas region in maintaining thermal comfort

    SciTech Connect

    Bentley, D.; Chabannes, G.

    1982-01-01

    Traditional building responses to the Central Texas climate are compared and evaluated in a parametric study. Building parameters of size, shape, orientation, capacitance and resistance values of materials, ceiling height, porch chading devices, and ventilation strategies are simulated using the DEROB computer code. Unassisted thermal comfort parameters of air temperature and mean radiant surface temperature are tabulated by hour into temperature bins to allow comparison of the relative effect of each response. Results indicate that high capacitance materials are more effective in maintaining thermal comfort in winter, and high resistance materials are more effective in summer. Building elongation improves summer performance, but reduces winter performance. Increased ceiling height provides marginal improvement in both winter and summer performance of traditional structures. The presence of a porch shading device improves summer performance slightly, but degrades winter performance by a similar degree. Ventilation strategies also show an improvement in summer building performance.

  16. Aircraft motion and passenger comfort response data from TIFS ride-quality flight experiments

    NASA Technical Reports Server (NTRS)

    Schoonover, W. E., Jr.

    1976-01-01

    The aircraft motion data and passenger comfort response data obtained during ride-quality flight experiments using the USAD Total In-Flight Simulator (TIFS) are given. During each of 40 test flights, 10 passenger subjects individually assessed the ride comfort of various types of aircraft motions. The 115 individuals who served as passenger subjects were selected to be representative of air travelers in general. Aircraft motions tested consisted of both random and sinusoidal oscillations in various combinations of five degrees of freedom (transverse, normal, roll, pitch, and yaw), as well as of terminal-area flight maneuvers. The data are sufficiently detailed to allow analysis of passenger reactions to flight environments, evaluation of the use of a portable environment measuring/recording system and comparison of the in-flight simulator responses with input commands.

  17. Safe and comfortable assistance for elderly during lie-to-sit transition

    NASA Astrophysics Data System (ADS)

    Pervez, Aslam; Ryu, Jeha

    2009-12-01

    While assisting elderly in mobility tasks (such as walking, sit-to-stand, and lie-to-sit etc.) the elderly and robots work cooperatively and remain in continuous physical contact during the task. In order to realize a safe and comfortable assistance to elderly, the natural motion patterns of the elderly during a particular task should be respected and augmented by the robot. This paper is focused on designing robot motion paths that accommodate the natural movement patterns of elderly and are based on modeling the caregivers' actions reported in the biomechanics and elder-care literature. As an example, one such motion path for lie-to-sit and sit-to-stand activities is implemented on SpiderBot-II and experimental results are reported in the paper. Proposed motion path is compared with conventional motion path by evaluating through quantitative safety and comfort indices for mobility assistance robots.

  18. Safe and comfortable assistance for elderly during lie-to-sit transition

    NASA Astrophysics Data System (ADS)

    Pervez, Aslam; Ryu, Jeha

    2010-01-01

    While assisting elderly in mobility tasks (such as walking, sit-to-stand, and lie-to-sit etc.) the elderly and robots work cooperatively and remain in continuous physical contact during the task. In order to realize a safe and comfortable assistance to elderly, the natural motion patterns of the elderly during a particular task should be respected and augmented by the robot. This paper is focused on designing robot motion paths that accommodate the natural movement patterns of elderly and are based on modeling the caregivers' actions reported in the biomechanics and elder-care literature. As an example, one such motion path for lie-to-sit and sit-to-stand activities is implemented on SpiderBot-II and experimental results are reported in the paper. Proposed motion path is compared with conventional motion path by evaluating through quantitative safety and comfort indices for mobility assistance robots.

  19. Radiation doses to paediatric patients and comforters undergoing chest X rays.

    PubMed

    Sulieman, A; Vlychou, M; Tsougos, I; Theodorou, K

    2011-09-01

    Pneumonia is an important cause of hospital admission among children in the developed world and it is estimated to be responsible for 3-18 % of all paediatric admissions. Chest X ray is an important examination for pneumonia diagnosis and for evaluation of complications. This study aims to determine the entrance surface dose (ESD), organ, effective doses and propose a local diagnostic reference level. The study was carried out at the university hospital of Larissa, Greece. Patients were divided into three groups: organ and effective doses were estimated using National Radiological Protection Board software. The ESD was determined by thermoluminescent dosemeters for 132 children and 76 comforters. The average ESD value was 55 ± 8 µGy. The effective dose for patients was 11.2 ± 5 µSv. The mean radiation dose for comforter is 22 ± 3 µGy. The radiation dose to the patients is well within dose constraint, in the light of the current practice.

  20. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    NASA Astrophysics Data System (ADS)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  1. What Is an Acoustic Neuroma

    MedlinePlus

    ... Acoustic Neuroma An acoustic neuroma, also called a vestibular schwannoma, is a rare benign tumor of the ... Acoustic Neuroma? An acoustic neuroma, known as a vestibular schwannoma, is a benign (non-cancerous) growth that ...

  2. Acoustic Radiation Force Impulse (ARFI) and Transient Elastography (TE) for evaluation of liver fibrosis in HIV-HCV co-infected patients

    PubMed Central

    2014-01-01

    Background Transient elastography (TE) is widely used for non-invasive assessment of liver fibrosis in HIV-HCV co-infected patients. TE, however, cannot determine liver morphology. Acoustic radiation force impulse (ARFI) imaging is a novel procedure enabling assessment of liver fibrosis during a conventional ultrasonographic examination. This study evaluated the correlation between liver fibrosis measurements by TE and ARFI. Methods Each of 46 HIV-HCV patients underwent both ARFI and TE within 6 months. Patients were evaluated by the “equivalent METAVIR” scoring system, using previously established cut-off values. Agreements between the ARFI and TE scores were estimated by Kappa coefficients, with Kappa values ≥0.40, ≥0.60, and ≥0.80 defined as moderate, good and very good agreement, respectively. Results ARFI and TE yielded "Equivalent Metavir" fibrosis scores of F1 in 26 and 31 patients, respectively; F2 in nine and seven, respectively; F3 in three and two, respectively; and F4 in eight and six, respectively. The two methods showed very good agreement in predicting overall stages [Kappa = 0.82] and for F ≥3 [Kappa = 0.80] and moderate agreement in predicting significant fibrosis F ≥2 [Kappa = 0.50]. Morphologic ultrasound analysis concomitant to ARFI detected two hepatocarcinomas. Conclusions ARFI showed promising results in the non-invasive assessment of liver fibrosis in HIV-HCV patients, with liver fibrosis staging similar to that of TE. Moreover, ARFI can assess morphology and fibrosis during the same session. PMID:25041708

  3. Automatic detection of wheezes by evaluation of multiple acoustic feature extraction methods and C-weighted SVM

    NASA Astrophysics Data System (ADS)

    Sosa, Germán. D.; Cruz-Roa, Angel; González, Fabio A.

    2015-01-01

    This work addresses the problem of lung sound classification, in particular, the problem of distinguishing between wheeze and normal sounds. Wheezing sound detection is an important step to associate lung sounds with an abnormal state of the respiratory system, usually associated with tuberculosis or another chronic obstructive pulmonary diseases (COPD). The paper presents an approach for automatic lung sound classification, which uses different state-of-the-art sound features in combination with a C-weighted support vector machine (SVM) classifier that works better for unbalanced data. Feature extraction methods used here are commonly applied in speech recognition and related problems thanks to the fact that they capture the most informative spectral content from the original signals. The evaluated methods were: Fourier transform (FT), wavelet decomposition using Wavelet Packet Transform bank of filters (WPT) and Mel Frequency Cepstral Coefficients (MFCC). For comparison, we evaluated and contrasted the proposed approach against previous works using different combination of features and/or classifiers. The different methods were evaluated on a set of lung sounds including normal and wheezing sounds. A leave-two-out per-case cross-validation approach was used, which, in each fold, chooses as validation set a couple of cases, one including normal sounds and the other including wheezing sounds. Experimental results were reported in terms of traditional classification performance measures: sensitivity, specificity and balanced accuracy. Our best results using the suggested approach, C-weighted SVM and MFCC, achieve a 82.1% of balanced accuracy obtaining the best result for this problem until now. These results suggest that supervised classifiers based on kernel methods are able to learn better models for this challenging classification problem even using the same feature extraction methods.

  4. Children's exposure to indoor air in urban nurseries-part I: CO{sub 2} and comfort assessment

    SciTech Connect

    Branco, P.T.B.S.; Alvim-Ferraz, M.C.M.; Martins, F.G.; Sousa, S.I.V.

    2015-07-15

    Indoor air quality (IAQ) in nurseries is an emerging case-study. Thus, this study, as the Part I of the larger study “Children's exposure to indoor air in urban nurseries”, aimed to: i) evaluate nurseries’ indoor concentrations of carbon dioxide (CO{sub 2}), a global IAQ indicator, in class and lunch rooms; ii) assess indoor comfort parameters–temperature (T) and relative humidity (RH); and iii) analyse them according to guidelines and references for IAQ, comfort and children's health. Indoor continuous measurements were performed. Non-compliances with guidelines were found in comfort parameters, which could cause discomfort situations and also microbial proliferation. Exceedances in CO{sub 2} concentrations were also found and they were caused by poor ventilation and high classroom occupation. More efficient ventilation and control of comfort parameters, as well as to reduce occupation by reviewing Portuguese legislation on that matter, would certainly improve IAQ and comfort in nurseries and consequently safeguard children's health. - Highlights: • High occupation and poor ventilation were main determinants of IAQ in nurseries. • T and RH indoor values found in nurseries are likely to cause thermal discomfort. • Building characteristics and an inadequate ventilation determined T and RH values. • High CO{sub 2} concentrations found could indicate accumulation of other air pollutants.

  5. Applying outdoor environment to develop health, comfort, and energy saving in the office in hot-humid climate.

    PubMed

    Chen, Rong; Sung, Wen-Pei; Chang, Hung-Chang; Chi, Yi-Rou

    2013-01-01

    A human life demand set to emerge in the future is the achievement of sustainability by maintaining a comfortable indoor environment without excessive reliance on energy-consuming air conditioners. The major research processes in this study are: (1) measuring indoor air quality and thermal comfort to evaluate the comfort of an indoor environment; (2) implementing questionnaire survey analysis to explore people's environmental self-perceptions and conducting a meta-analysis of the measurement results for air quality and physical aspects; and (3) constructing an indoor monitoring and management system. The experimental and analysis results of this research reveal that most of the office occupants preferred a cooler environment with a lower temperature. Additionally, because the summers in Taiwan are humid and hot, the occupants of an indoor space tend to feel uncomfortable because of the high humidity and poor indoor air quality. Therefore, Variable Air Volume (VAV), two air intakes, and exhaust plant are installed to improve indoor environment. After improvement, a lower temperature (approximately 21.2-23.9°C) indirectly reduces humidity, thereby making the occupants comfortable. Increasing air velocity to 0.1~0.15 m/s, the carbon dioxide concentrations decrease below the requirement of the WHO. Ninety-five percent of the workers corresponded to the standard comfort zone after this improvement.

  6. An Open Source “Smart Lamp” for the Optimization of Plant Systems and Thermal Comfort of Offices

    PubMed Central

    Salamone, Francesco; Belussi, Lorenzo; Danza, Ludovico; Ghellere, Matteo; Meroni, Italo

    2016-01-01

    The article describes the design phase, development and practical application of a smart object integrated in a desk lamp and called “Smart Lamp”, useful to optimize the indoor thermal comfort and energy savings that are two important workplace issues where the comfort of the workers and the consumption of the building strongly affect the economic balance of a company. The Smart Lamp was built using a microcontroller, an integrated temperature and relative humidity sensor, some other modules and a 3D printer. This smart device is similar to the desk lamps that are usually found in offices but it allows one to adjust the indoor thermal comfort, by interacting directly with the air conditioner. After the construction phase, the Smart Lamp was installed in an office normally occupied by four workers to evaluate the indoor thermal comfort and the cooling consumption in summer. The results showed how the application of the Smart Lamp effectively reduced the energy consumption, optimizing the thermal comfort. The use of DIY approach combined with read-write functionality of websites, blog and social platforms, also allowed to customize, improve, share, reproduce and interconnect technologies so that anybody could use them in any occupied environment. PMID:26959035

  7. Applying Outdoor Environment to Develop Health, Comfort, and Energy Saving in the Office in Hot-Humid Climate

    PubMed Central

    Chen, Rong; Sung, Wen-Pei; Chang, Hung-Chang; Chi, Yi-Rou

    2013-01-01

    A human life demand set to emerge in the future is the achievement of sustainability by maintaining a comfortable indoor environment without excessive reliance on energy-consuming air conditioners. The major research processes in this study are: (1) measuring indoor air quality and thermal comfort to evaluate the comfort of an indoor environment; (2) implementing questionnaire survey analysis to explore people's environmental self-perceptions and conducting a meta-analysis of the measurement results for air quality and physical aspects; and (3) constructing an indoor monitoring and management system. The experimental and analysis results of this research reveal that most of the office occupants preferred a cooler environment with a lower temperature. Additionally, because the summers in Taiwan are humid and hot, the occupants of an indoor space tend to feel uncomfortable because of the high humidity and poor indoor air quality. Therefore, Variable Air Volume (VAV), two air intakes, and exhaust plant are installed to improve indoor environment. After improvement, a lower temperature (approximately 21.2–23.9°C) indirectly reduces humidity, thereby making the occupants comfortable. Increasing air velocity to 0.1 ~ 0.15 m/s, the carbon dioxide concentrations decrease below the requirement of the WHO. Ninety-five percent of the workers corresponded to the standard comfort zone after this improvement. PMID:24311976

  8. Validation and Simulation of Ares I Scale Model Acoustic Test - 2 - Simulations at 5 Foot Elevation for Evaluation of Launch Mount Effects

    NASA Technical Reports Server (NTRS)

    Strutzenberg, Louise L.; Putman, Gabriel C.

    2011-01-01

    The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. Expanding from initial simulations of the ASMAT setup in a held down configuration, simulations have been performed using the Loci/CHEM computational fluid dynamics software for ASMAT tests of the vehicle at 5 ft. elevation (100 ft. real vehicle elevation) with worst case drift in the direction of the launch tower. These tests have been performed without water suppression and have compared the acoustic emissions for launch structures with and without launch mounts. In addition, simulation results have also been compared to acoustic and imagery data collected from similar live-fire tests to assess the accuracy of the simulations. Simulations have shown a marked change in the pattern of emissions after removal of the launch mount with a reduction in the overall acoustic environment experienced by the vehicle and the formation of highly directed acoustic waves moving across the platform deck. Comparisons of simulation results to live-fire test data showed good amplitude and temporal correlation and imagery comparisons over the visible and infrared wavelengths showed qualitative capture of all plume and pressure wave evolution features.

  9. Comfort, satisfaction, and anxiolysis in surgical patients using a patient-adjustable comfort warming system: a prospective randomized clinical trial.

    PubMed

    O'Brien, Denise; Greenfield, Mary Lou V H; Anderson, Jane E; Smith, Beverly A; Morris, Michelle

    2010-04-01

    Comfort warming systems aim to produce a comfortable local environment over which the individual patient has control. We studied a patient-adjustable comfort warming system using the Bair PAWS (Patient Adjustable Warming System) (Arizant Healthcare, Inc, Eden Prairie, MN), specifically to study comfort warming rather than therapeutic warming. One-hundred thirty patients were enrolled in this prospective randomized clinical trial, with 58 patients randomized to the patient warming gown, and 72 randomized to the warm blanket group. Groups were similar for gender, age, height, weight, surgical time, body surface area, and body mass index. The patient-adjustable warming system group had perceived greater control and satisfaction at 30 minutes after treatment was initiated compared with the warmed blanket control group. However, there were no differences in satisfaction levels with thermal comfort among those patients contacted one day postoperatively. Additional research is needed to improve external validity of study findings. Further refinement of a nursing definition of thermal comfort should be explored. PMID:20359643

  10. Threshold improvement and acoustic gain with hearing aids.

    PubMed

    Walden, B E; Kasten, R N

    1976-01-01

    Aided speech reception thresholds were obtained from 20 hearing-impaired listeners with three hearing aids adjusted to confort settings, and with the aids adjusted to deliver 40 dB of acoustic gain. The aided speech reception threshold under each condition was substracted from the unaided speech reception threshold to yield a measure of threshold improvement. Threshold improvement and acoustic gain comparisons revealed that, at comfort setting, these two measures were quite similar. However, at the 40-dB gain setting, acoustic gain exceeded threshold improvement by an average of 5.6 dB. For the high-gain condition, it appeared that the threshold improvement obtained by subjects with relatively good unaided sensitivity was limited by the ambient noise in the test chamber.

  11. Applied topology optimization of vibro-acoustic hearing instrument models

    NASA Astrophysics Data System (ADS)

    Søndergaard, Morten Birkmose; Pedersen, Claus B. W.

    2014-02-01

    Designing hearing instruments remains an acoustic challenge as users request small designs for comfortable wear and cosmetic appeal and at the same time require sufficient amplification from the device. First, to ensure proper amplification in the device, a critical design challenge in the hearing instrument is to minimize the feedback between the outputs (generated sound and vibrations) from the receiver looping back into the microphones. Secondly, the feedback signal is minimized using time consuming trial-and-error design procedures for physical prototypes and virtual models using finite element analysis. In the present work it is demonstrated that structural topology optimization of vibro-acoustic finite element models can be used to both sufficiently minimize the feedback signal and to reduce the time consuming trial-and-error design approach. The structural topology optimization of a vibro-acoustic finite element model is shown for an industrial full scale model hearing instrument.

  12. Threshold improvement and acoustic gain with hearing aids.

    PubMed

    Walden, B E; Kasten, R N

    1976-01-01

    Aided speech reception thresholds were obtained from 20 hearing-impaired listeners with three hearing aids adjusted to confort settings, and with the aids adjusted to deliver 40 dB of acoustic gain. The aided speech reception threshold under each condition was substracted from the unaided speech reception threshold to yield a measure of threshold improvement. Threshold improvement and acoustic gain comparisons revealed that, at comfort setting, these two measures were quite similar. However, at the 40-dB gain setting, acoustic gain exceeded threshold improvement by an average of 5.6 dB. For the high-gain condition, it appeared that the threshold improvement obtained by subjects with relatively good unaided sensitivity was limited by the ambient noise in the test chamber. PMID:938347

  13. Ultrasonic field profile evaluation in acoustically inhomogeneous anisotropic materials using 2D ray tracing model: Numerical and experimental comparison.

    PubMed

    Kolkoori, S R; Rahman, M-U; Chinta, P K; Ktreutzbruck, M; Rethmeier, M; Prager, J

    2013-02-01

    Ultrasound propagation in inhomogeneous anisotropic materials is difficult to examine because of the directional dependency of elastic properties. Simulation tools play an important role in developing advanced reliable ultrasonic non destructive testing techniques for the inspection of anisotropic materials particularly austenitic cladded materials, austenitic welds and dissimilar welds. In this contribution we present an adapted 2D ray tracing model for evaluating ultrasonic wave fields quantitatively in inhomogeneous anisotropic materials. Inhomogeneity in the anisotropic material is represented by discretizing into several homogeneous layers. According to ray tracing model, ultrasonic ray paths are traced during its energy propagation through various discretized layers of the material and at each interface the problem of reflection and transmission is solved. The presented algorithm evaluates the transducer excited ultrasonic fields accurately by taking into account the directivity of the transducer, divergence of the ray bundle, density of rays and phase relations as well as transmission coefficients. The ray tracing model is able to calculate the ultrasonic wave fields generated by a point source as well as a finite dimension transducer. The ray tracing model results are validated quantitatively with the results obtained from 2D Elastodynamic Finite Integration Technique (EFIT) on several configurations generally occurring in the ultrasonic non destructive testing of anisotropic materials. Finally, the quantitative comparison of ray tracing model results with experiments on 32mm thick austenitic weld material and 62mm thick austenitic cladded material is discussed.

  14. The death of recency: Relationship between end-state comfort and serial position effects in serial recall: Logan and Fischman (2011) revisited.

    PubMed

    Logan, Samuel W; Fischman, Mark G

    2015-12-01

    Two experiments examined the dynamic interaction between cognitive resources in short-term memory and bimanual object manipulation by extending recent research by Logan and Fischman (2011). In Experiment 1, 16 participants completed a bimanual end-state comfort task and a memory task requiring serial recall of 12 words or pictures. The end-state comfort task involved moving two glasses between two shelves. Participants viewed the items, performed the end-state comfort task, and then serially recalled the items. Recall was evaluated by the presence or absence of primacy and recency effects. The end-state comfort effect (ESCE) was assessed by the percentage of initial hand positions that allowed the hands to end comfortably. The main findings indicated that the ESCE was disrupted; the primacy effect remained intact; and the recency effect disappeared regardless of the type of memory item recalled. In Experiment 2, 16 participants viewed six items, performed an end-state comfort task, viewed another six items, and then serially recalled all 12 items. Results were essentially the same as in Experiment 1. Findings suggest that executing a bimanual end-state comfort task, regardless of when it is completed during a memory task, diminishes the recency effect irrespective of the type of memory item.

  15. Using the Comfortability-in-Learning Scale to Enhance Positive Classroom Learning Environments

    ERIC Educational Resources Information Center

    Kiener, Michael; Green, Peter; Ahuna, Kelly

    2014-01-01

    A goal of higher education is to advance learning. This study examined the role "comfortability" plays in that process. Defined as the level of comfort students experience with their classmates, instructor, and course material, comfortability addresses how secure a student feels in the classroom. Comfortability was assessed multiple…

  16. Human comfort response to random motions with a dominant longitudinal motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with longitudinal acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.

  17. Human comfort response to random motions with a dominant transverse motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with transverse acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.

  18. Passive acoustic monitoring of human physiology during activity indicates health and performance of soldiers and firefighters

    NASA Astrophysics Data System (ADS)

    Scanlon, Michael V.

    2003-04-01

    The Army Research Laboratory has developed a unique gel-coupled acoustic physiological monitoring sensor that has acoustic impedance properties similar to the skin. This facilitates the transmission of body sounds into the sensor pad, yet significantly repels ambient airborne noises due to an impedance mismatch. The sensor's sensitivity and bandwidth produce excellent signatures for detection and spectral analysis of diverse physiological events. Acoustic signal processing detects heartbeats, breaths, wheezes, coughs, blood pressure, activity, motion, and voice for communication and automatic speech recognition. The health and performance of soldiers, firefighters, and other first responders in strenuous and hazardous environments can be continuously and remotely monitored with body-worn acoustic sensors. Comfortable acoustic sensors can be in a helmet or in a strap around the neck, chest, and wrist. Noise-canceling sensor arrays help remove out-of-phase motion noise and enhance covariant physiology by using two acoustic sensors on the front sides of the neck and two additional acoustic sensors on each wrist. Pulse wave transit time between neck and wrist acoustic sensors will indicate systolic blood pressure. Larger torso-sized arrays can be used to acoustically inspect the lungs and heart, or built into beds for sleep monitoring. Acoustics is an excellent input for sensor fusion.

  19. End-state comfort and joint configuration variance during reaching.

    PubMed

    Solnik, Stanislaw; Pazin, Nemanja; Coelho, Chase J; Rosenbaum, David A; Scholz, John P; Zatsiorsky, Vladimir M; Latash, Mark L

    2013-03-01

    This study joined two approaches to motor control. The first approach comes from cognitive psychology and is based on the idea that goal postures and movements are chosen to satisfy task-specific constraints. The second approach comes from the principle of motor abundance and is based on the idea that control of apparently redundant systems is associated with the creation of multi-element synergies stabilizing important performance variables. The first approach has been tested by relying on psychophysical ratings of comfort. The second approach has been tested by estimating variance along different directions in the space of elemental variables such as joint postures. The two approaches were joined here. Standing subjects performed series of movements in which they brought a hand-held pointer to each of four targets oriented within a frontal plane, close to or far from the body. The subjects were asked to rate the comfort of the final postures, and the variance of their joint configurations during the steady state following pointing was quantified with respect to pointer endpoint position and pointer orientation. The subjects showed consistent patterns of comfort ratings among the targets, and all movements were characterized by multi-joint synergies stabilizing both pointer endpoint position and orientation. Contrary to what was expected, less comfortable postures had higher joint configuration variance than did more comfortable postures without major changes in the synergy indices. Multi-joint synergies stabilized the pointer position and orientation similarly across a range of comfortable/uncomfortable postures. The results are interpreted in terms conducive to the two theoretical frameworks underlying this work, one focusing on comfort ratings reflecting mean postures adopted for different targets and the other focusing on indices of joint configuration variance. PMID:23288326

  20. End-state comfort and joint configuration variance during reaching

    PubMed Central

    Solnik, Stanislaw; Pazin, Nemanja; Coelho, Chase J.; Rosenbaum, David A.; Scholz, John P.; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2013-01-01

    This study joined two approaches to motor control. The first approach comes from cognitive psychology and is based on the idea that goal postures and movements are chosen to satisfy task-specific constraints. The second approach comes from the principle of motor abundance and is based on the idea that control of apparently redundant systems is associated with the creation of multi-element synergies stabilizing important performance variables. The first approach has been tested by relying on psychophysical ratings of comfort. The second approach has been tested by estimating variance along different directions in the space of elemental variables such as joint postures. The two approaches were joined here. Standing subjects performed series of movements in which they brought a hand-held pointer to each of four targets oriented within a frontal plane, close to or far from the body. The subjects were asked to rate the comfort of the final postures, and the variance of their joint configurations during the steady state following pointing was quantified with respect to pointer endpoint position and pointer orientation. The subjects showed consistent patterns of comfort ratings among the targets, and all movements were characterized by multi-joint synergies stabilizing both pointer endpoint position and orientation. Contrary to what was expected, less comfortable postures had higher joint configuration variance than did more comfortable postures without major changes in the synergy indices. Multi-joint synergies stabilized the pointer position and orientation similarly across a range of comfortable/uncomfortable postures. The results are interpreted in terms conducive to the two theoretical frameworks underlying this work, one focusing on comfort ratings reflecting mean postures adopted for different targets and the other focusing on indices of joint configuration variance. PMID:23288326

  1. Symptoms of Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  2. Acoustic Neuroma Educational Video

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  3. Frequency steerable acoustic transducers

    NASA Astrophysics Data System (ADS)

    Senesi, Matteo

    Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing

  4. Passivhaus: indoor comfort and energy dynamic analysis.

    NASA Astrophysics Data System (ADS)

    Guida, Antonella; Pagliuca, Antonello; Cardinale, Nicola; Rospi, Gianluca

    2013-04-01

    The research aims to verify the energy performance as well as the indoor comfort of an energy class A+ building, built so that the sum of the heat passive contributions of solar radiation, transmitted through the windows, and the heat generated inside the building, are adeguate to compensate for the envelope loss during the cold season. The building, located in Emilia Romagna (Italy), was built using a wooden structure, an envelope realized using a pinewood sandwich panels (transmittance U = 0.250 W/m2K) and, inside, a wool flax insulation layer and thermal window frame with low-emissivity glass (U = 0524 W/m2K). The building design and construction process has followed the guidelines set by "CasaClima". The building has been modeled in the code of dynamic calculation "Energy Plus" by the Design Builder application and divided it into homogenous thermal zones, characterized by winter indoor temperature set at 20 ° (+ / - 1 °) and summer indoor temperature set at 26 ° (+ / - 1 °). It has modeled: the envelope, as described above, the "free" heat contributions, the air conditioning system, the Mechanical Ventilation system as well as home automation solutions. The air conditioning system is an heat pump, able to guarantee an optimization of energy consumption (in fact, it uses the "free" heat offered by the external environment for conditioning indoor environment). As regards the air recirculation system, it has been used a mechanical ventilation system with internal heat cross-flow exchanger, with an efficiency equal to 50%. The domotic solutions, instead, regard a system for the control of windows external screening using reeds, adjustable as a function of incident solar radiation and a lighting management system adjusted automatically using a dimmer. A so realized building meets the requirement imposed from Italian standard UNI/TS 11300 1, UNI/TS 11300 2 and UNI/TS 11300 3. The analysis was performed according to two different configurations: in "spontaneous

  5. Acoustic emission frequency discrimination

    NASA Technical Reports Server (NTRS)

    Sugg, Frank E. (Inventor); Graham, Lloyd J. (Inventor)

    1988-01-01

    In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered.

  6. The South Pole Acoustic Test Setup (SPATS)

    NASA Astrophysics Data System (ADS)

    Laihem, Karim; IceCube Collaboration

    2012-11-01

    New detection techniques for (GZK) neutrinos are required for instrumenting a large detector volume needed to observe the low neutrino fluxes at the EeV energy range. Studies on a larger IceCube Neutrino Observatory at the South Pole have been intensively investigated in the last decade. A larger effective volume at a reasonable cost is possible if an acoustic array is a part of a large hybrid detector which includes radio and the existing optical array. The feasibility and the physics capabilities of an acoustic array at the South Pole depend on the knowledge of the acoustic properties of the ice such as the sound speed, the attenuation length, the background noise level and the transient rate. To investigate the ice properties, the first three acoustic strings of the South Pole Acoustic Test Setup (SPATS) have been deployed in the austral summer 2006/2007, then completed with an additional string in 2007/2008. With its four strings SPATS was able to evaluate in situ the acoustic properties of the South Pole ice in the 10-100 kHz frequency range. In this paper the performance of SPATS is described, results on the acoustic ice properties are presented and a new drilling method to deploy acoustic strings in ice is introduced.

  7. Tutorial on architectural acoustics

    NASA Astrophysics Data System (ADS)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  8. Air movement and thermal comfort in tropical schools

    SciTech Connect

    Kwok, A.G.

    1997-12-31

    Comfort standards (ASHRAE 55, ISO 7730) specify exact physical criteria for producing acceptable thermal environments, which include temperature, air movement, and humidity limits that are often difficult to comply with, particularly in hot and humid tropical climates such as Hawaii`s. Are these temperate climate, air-conditioning based standards appropriate to situations in tropical climates? During two seasons, thermal comfort experiments conducted in Hawaii in both naturally-ventilated and air-conditioned classrooms polled responses from 3,544 students and teachers, while they simultaneously measured indoor climate variables. Results indicated that more than 75% of the classrooms were not within comfort zone prescriptions. Air-conditioned classrooms were overcooled, causing half of the occupants to experience cool thermal sensations. Although many naturally-ventilated classrooms were 3--4 C warmer than comfort zone requirements, occupants found conditions acceptable. Occupants generally preferred more air movement, even though measured air velocities met the Standard`s criteria. Comfort responses are discussed in terms of comparisons to ASHRAE Standard 55-92.

  9. The psychobiology of comfort eating: implications for neuropharmacological interventions.

    PubMed

    Gibson, E Leigh

    2012-09-01

    Comfort eating, that is eating induced by negative affect, has been a core theme of explanations for overeating and obesity. Psychobiological explanations and processes underlying comfort eating are examined, as well as its prevalence in clinical and nonclinical populations, to consider who may be susceptible, whether certain foods are comforting, and what the implications for treatment may be. Comfort eating may occur in a substantial minority, particularly in women and the obese. Human and animal theories and models of emotional or stress-induced eating show some convergence, and may incorporate genetic predispositions such as impulsivity and reward sensitivity, associated with dopamine dysregulation underlying incentive salience. Comfort eaters show vulnerability to depression, emotional dysregulation and a need to escape negative affect and rumination. During negative affect, they preferentially consume sweet, fatty, energy-dense food, which may confer protection against stress, evidenced by suppression of the hypothalamic-pituitary-adrenal axis response, although activation of the hypothalamic-pituitary-adrenal axis may itself drive appetite for these palatable foods, and the risk of weight gain is increased. Benefits to mood may be transient, but perhaps sufficient to encourage repeated attempts to prolong mood improvement or distract from negative rumination. Cognitive behavioural treatments may be useful, but reliable drug therapy awaits further pharmacogenomic developments.

  10. Evaluation of Acoustic Radiation Force Impulse Imaging (ARFI) for the Determination of Liver Stiffness Using Transient Elastography as a Reference in Children

    PubMed Central

    Sagir, A.; Ney, D.; Oh, J.; Pandey, S.; Kircheis, G.; Mayatepek, E.; Häussinger, D.

    2015-01-01

    Purpose: Transient elastography (Fibroscan©; (FS)) and acoustic radiation force impulse imaging (ARFI) represent noninvasive, user-friendly and quick methods providing an objective and reproducible measure of liver stiffness. The aim of the study was to evaluate cut-off values and performance of ARFI measurements in children using transient elastography as a reference. Methods/Patients: A total of 198 children were enrolled in this study. All patients underwent liver stiffness measurements with FS (FS-LS) as well as ARFI (with shear wave velocity quantification; ARFI-SWV) and the performance of ARFI in comparison to FS was studied. Results: Significantly higher rates of successful measurements were found for ARFI compared to FS (198/198 (100%) vs. 160/198 (80.8%); p<0.001). ARFI-SWV correlated significantly with FS-LS (r=0.751, p=0.001). ARFI-SWV increased significantly with the stage of fibrosis (1.19+0.15 m/s for patients with FS-LS<7.6 kPa); 1.34+0.22 m/s for patients with 7.613.0 kPa). ARFI-SWV cut-off values were identified for no significant fibrosis (1.31 m/s; sensitivity 61.8% and specificity 79.5%) and for liver cirrhosis (1.63 m/s; sensitivity 70.0% and specificity 97.4%). The median values of liver stiffness measured by FS were age-dependent in 90 children without liver diseases with 4.8, 5.6, and 5.7 kPa in children 0–5, 6–11, and 12–18 years, respectively.

  11. Lighting energy savings potential of split-pane electrochromic windows controlled for daylighting with visual comfort

    SciTech Connect

    Software, Anyhere; Fernandes, Luis; Lee, Eleanor; Ward, Greg

    2013-03-15

    A simulation study was conducted to evaluate lighting energy savings of split-pane electrochromic (EC) windows controlled to satisfy key visual comfort parameters. Using the Radiance lighting simulation software, interior illuminance and luminance levels were computed for a south-facing private office illuminated by a window split into two independently-controlled EC panes. The transmittance of these was optimized hourly for a workplane illuminance target while meeting visual comfort constraints, using a least-squares algorithm with linear inequality constraints. Blinds were successively deployed until visual comfort criteria were satisfied. The energy performance of electrochromics proved to be highly dependent on how blinds were controlled. With hourly blind position adjustments, electrochromics showed significantly higher (62percent and 53percent, respectively without and with overhang) lighting energy consumption than clear glass. With a control algorithm designed to better approximate realistic manual control by an occupant, electrochromics achieved significant savings (48percent and 37percent, respectively without and with overhang). In all cases, energy consumption decreased when the workplace illuminance target was increased. In addition, the fraction of time during which the occupant had an unobstructed view of the outside was significantly greater with electrochromics: 10 months out of the year versus a handful of days for the reference case.

  12. Impact of three biological decontamination methods on filtering facepiece respirator fit, odor, comfort, and donning ease.

    PubMed

    Viscusi, Dennis J; Bergman, Michael S; Novak, Debra A; Faulkner, Kimberly A; Palmiero, Andrew; Powell, Jeffrey; Shaffer, Ronald E

    2011-07-01

    The objective of this study was to determine if ultraviolet germicidal irradiation (UVGI), moist heat incubation (MHI), or microwave-generated steam (MGS) decontamination affects the fitting characteristics, odor, comfort, or donning ease of six N95 filtering facepiece respirator (FFR) models. For each model, 10 experienced test subjects qualified for the study by passing a standard OSHA quantitative fit test. Once qualified, each subject performed a series of fit tests to assess respirator fit and completed surveys to evaluate odor, comfort, and donning ease with FFRs that were not decontaminated (controls) and with FFRs of the same model that had been decontaminated. Respirator fit was quantitatively measured using a multidonning protocol with the TSI PORTACOUNT Plus and the N95 Companion accessory (designed to count only particles resulting from face to face-seal leakage). Participants' subjective appraisals of the respirator's odor, comfort, and donning ease were captured using a visual analog scale survey. Wilcoxon signed rank tests compared median values for fit, odor, comfort, and donning ease for each FFR and decontamination method against their respective controls for a given model. Two of the six FFRs demonstrated a statistically significant reduction (p < 0.05) in fit after MHI decontamination. However, for these two FFR models, post-decontamination mean fit factors were still ≥ 100. One of the other FFRs demonstrated a relatively small though statistically significant increase (p < 0.05) in median odor response after MHI decontamination. These data suggest that FFR users with characteristics similar to those in this study population would be unlikely to experience a clinically meaningful reduction in fit, increase in odor, increase in discomfort, or increased difficulty in donning with the six FFRs included in this study after UVGI, MHI, or MGS decontamination. Further research is needed before decontamination of N95 FFRs for purposes of reuse can be

  13. Comfort effects of a new car headrest with neck support.

    PubMed

    Franz, M; Durt, A; Zenk, R; Desmet, P M A

    2012-03-01

    This paper describes the design of a neck-/headrest to increase car comfort. Two studies were undertaken to create a new comfortable headrest with neck support. In experiment one, neck- and headrest data were gathered using 35 test subjects. The pressure distribution, stiffness of the foam material and position of the head and neck support were determined. In experiment two a full adjustable final headrest with adjustable neck support was constructed and tested with 12 subjects using a new adjustable headrest under virtual reality driving conditions. Experiment two showed that the headrest with the new/adjustable neck support was favoured by the majority of the subjects. 83% were satisfied with the stiffness of the material. 92% were satisfied with the size of the neck- and headrest. All subjects mentioned that the neck support is a comfort benefit in calm traffic conditions or on the motorway.

  14. Guidelines on Thermal Comfort of Air Conditioned Indoor Environment

    NASA Astrophysics Data System (ADS)

    Miura, Toyohiko

    The thermal comfort of air conditioned indoor environment for workers depended, of course, on metabolic rate of work, race, sex, age, clothing, climate of the district and state of acclimatization. The attention of the author was directed to the seasonal variation and the sexual difference of comfortable temperature and a survey through a year was conducted on the thermal comfort, and health conditions of workers engaged in light work in a precision machine factory, in some office workers. Besides, a series of experiments were conducted for purpose of determinning the optimum temperature of cooling in summer time in relation to the outdoor temperature. It seemed that many of workers at present would prefer somewhat higher temperature than those before the World War II. Forty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerably heavier.

  15. Postural sway and perceived comfort in pointing tasks.

    PubMed

    Solnik, Stanislaw; Pazin, Nemanja; Coelho, Chase J; Rosenbaum, David A; Zatsiorsky, Vladimir M; Latash, Mark L

    2014-05-21

    In this study, we explored relations between indices of postural sway and perceived comfort during pointing postures performed by standing participants. The participants stood on a force plate, grasped a pointer with the dominant (right) hand, and pointed to targets located at four positions and at two distances from the body. We quantified postural sway over 60-s intervals at each pointing posture, and found no effects of target location or distance on postural sway indices. In contrast, comfort ratings correlated significantly with indices of one of the sway components, trembling. Our observations support the hypothesis that rambling and trembling sway components involve different neurophysiological mechanisms. They also suggest that subjective perception of comfort may be more important than the actual posture for postural sway. PMID:24686189

  16. Postural sway and perceived comfort in pointing tasks

    PubMed Central

    Solnik, Stanislaw; Pazin, Nemanja; Coelho, Chase J.; Rosenbaum, David A.; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2014-01-01

    In this study, we explored relations between indices of postural sway and perceived comfort during pointing postures performed by standing participants. The participants stood on a force plate, grasped a pointer with the dominant (right) hand, and pointed to targets located at four positions and at two distances from the body. We quantified postural sway over 60-s intervals at each pointing posture, and found no effects of target location or distance on postural sway indices. In contrast, comfort ratings correlated significantly with indices of one of the sway components, trembling. Our observations support the hypothesis that rambling and trembling sway components involve different neurophysiological mechanisms. They also suggest that subjective perception of comfort may be more important than the actual posture for postural sway. PMID:24686189

  17. Alternating pressure mattresses: comfort and quality of sleep.

    PubMed

    Grindley, A; Acres, J

    Comfort is particularly important for patients with terminal illness where the priority is to maximize quality of life. Equally important is effective pressure area care, as such patients are at high risk of developing pressure sores because of their poor general condition (Bale and Regnard, 1995). The present randomized controlled study set in a hospice focused on the development of methodology for assessing patient comfort and quality of sleep and used this to compare two widely used, alternating air pressure mattresses (the Nimbus II and the Pegasus Airwave). The Nimbus II mattress performed consistently better than the Pegasus Airwave in terms of patient comfort and quality of sleep. Features of the Nimbus II that may explain its better performance include less extreme changes in pressure, lower peak inflation pressures and the ability to automatically vary the pressure to suit the patient's position and weight.

  18. Acoustically based fetal heart rate monitor

    NASA Technical Reports Server (NTRS)

    Baker, Donald A.; Zuckerwar, Allan J.

    1991-01-01

    The acoustically based fetal heart rate monitor permits an expectant mother to perform the fetal Non-Stress Test in her home. The potential market would include the one million U.S. pregnancies per year requiring this type of prenatal surveillance. The monitor uses polyvinylidene fluoride (PVF2) piezoelectric polymer film for the acoustic sensors, which are mounted in a seven-element array on a cummerbund. Evaluation of the sensor ouput signals utilizes a digital signal processor, which performs a linear prediction routine in real time. Clinical tests reveal that the acoustically based monitor provides Non-Stress Test records which are comparable to those obtained with a commercial ultrasonic transducer.

  19. ACOUSTICAL STANDARDS NEWS.

    PubMed

    Stremmel, Neil; Struck, Christopher J

    2016-07-01

    American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Neil Stremmel.Comments are welcomed on all material in Acoustical Standards News.This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org. PMID:27475185

  20. Using Dashboards to Improve Energy and Comfort in Federal Buildings

    SciTech Connect

    Lawrence Berkeley National Laboratory; Marini, Kyle; Ghatikar, Girish; Diamond, Richard

    2011-02-01

    Federal agencies are taking many steps to improve the sustainability of their operations, including improving the energy efficiency of their buildings, promoting recycling and reuse of materials, encouraging carpooling and alternative transit schemes, and installing low flow water fixture units are just a few of the common examples. However, an often overlooked means of energy savings is to provide feedback to building users about their energy use through information dashboards connected to a building?s energy information system. An Energy Information System (EIS), broadly defined, is a package of performance monitoring software, data acquisition hardware, and communication systems that is used to collect, store, analyze, and display energy information. At a minimum, the EIS provides the whole-building energy-use information (Granderson 2009a). We define a ?dashboard? as a display and visualization tool that utilizes the EIS data and technology to provide critical information to users. This information can lead to actions resulting in energy savings, comfort improvements, efficient operations, and more. The tools to report analyzed information have existed in the information technology as business intelligence (Few 2006). The dashboard is distinguished from the EIS as a whole, which includes additional hardware and software components to collect and storage data, and analysis for resources and energy management (Granderson 2009b). EIS can be used for a variety of uses, including benchmarking, base-lining, anomaly detection, off-hours energy use evaluation, load shape optimization, energy rate analysis, retrofit and retro-commissioning savings (Granderson 2009a). The use of these EIS features depends on the specific users. For example, federal and other building managers may use anomaly detection to identify energy waste in a specific building, or to benchmark energy use in similar buildings to identify energy saving potential and reduce operational cost. There are

  1. Acoustic emission from composite materials. [nondestructive tests

    NASA Technical Reports Server (NTRS)

    Visconti, I. C.; Teti, R.

    1979-01-01

    The two basic areas where the acoustic emission (AE) technique can be applied are materials research and the evaluation of structural reliability. This experimental method leads to a better understanding of fracture mechanisms and is an NDT technique particularly well suited for the study of propagating cracks. Experiments are described in which acoustic emissions were unambiguously correlated with microstructural fracture mechanisms. The advantages and limitations of the AE technique are noted.

  2. Acoustic optic hybrid (AOH) sensor

    PubMed

    Matthews; Arrieta

    2000-09-01

    The ability of laser vibrometers to receive and process acoustic echoes from the water surface above a submerged target is established and evaluated. Sonar echoes from a submerged target are collected from the water surface by a laser vibrometer. Feasibility of this approach to sensing underwater sound is demonstrated. If the acoustic excitation at an otherwise undisturbed water surface is 195 to 168 dB re: 1 microPa, signal-to-noise ratio (SNR), at the vibrometer output, is shown to range from about 46 to 6 dB. Capillary waves and gravity waves at the water surface are expected and shown to have some destructive effect on the process of echo retrieval. A series of experiments to quantify the surface wave effects is described. The wave experiment results are reported. A successful attempt to acquire echoes from a submerged target over a grid of points for further processing into a three-dimensional image is made and described. The data acquisition and beamforming techniques constitute a three-dimensional, acoustic optic, synthetic aperture sonar (SAS). Beamformed images are included. For an aircraft towing acoustic sensors through the water with a mechanical link, this technique holds the promise of increased safety and improved fuel efficiency. PMID:11008811

  3. Acoustic optic hybrid (AOH) sensor

    PubMed

    Matthews; Arrieta

    2000-09-01

    The ability of laser vibrometers to receive and process acoustic echoes from the water surface above a submerged target is established and evaluated. Sonar echoes from a submerged target are collected from the water surface by a laser vibrometer. Feasibility of this approach to sensing underwater sound is demonstrated. If the acoustic excitation at an otherwise undisturbed water surface is 195 to 168 dB re: 1 microPa, signal-to-noise ratio (SNR), at the vibrometer output, is shown to range from about 46 to 6 dB. Capillary waves and gravity waves at the water surface are expected and shown to have some destructive effect on the process of echo retrieval. A series of experiments to quantify the surface wave effects is described. The wave experiment results are reported. A successful attempt to acquire echoes from a submerged target over a grid of points for further processing into a three-dimensional image is made and described. The data acquisition and beamforming techniques constitute a three-dimensional, acoustic optic, synthetic aperture sonar (SAS). Beamformed images are included. For an aircraft towing acoustic sensors through the water with a mechanical link, this technique holds the promise of increased safety and improved fuel efficiency.

  4. Acoustic Liner for Turbomachinery Applications

    NASA Technical Reports Server (NTRS)

    Huff, Dennis L.; Sutliff, Daniel L.; Jones, Michael G.; Hebsur, Mohan G.

    2010-01-01

    The purpose of this innovation is to reduce aircraft noise in the communities surrounding airports by significantly attenuating the noise generated by the turbomachinery, and enhancing safety by providing a containment barrier for a blade failure. Acoustic liners are used in today's turbofan engines to reduce noise. The amount of noise reduction from an acoustic liner is a function of the treatment area, the liner design, and the material properties, and limited by the constraints of the nacelle or casement design. It is desirable to increase the effective area of the acoustic treatment to increase noise suppression. Modern turbofan engines use wide-chord rotor blades, which means there is considerable treatment area available over the rotor tip. Turbofan engines require containment over the rotors for protection from blade failure. Traditional methods use a material wrap such as Kevlar integrated with rub strips and sometimes metal layers (sandwiches). It is possible to substitute the soft rub-strip material with an open-cell metallic foam that provides noise-reduction benefits and a sacrificial material in the first layer of the containment system. An open-cell foam was evaluated that behaves like a bulk acoustic liner, serves as a tip rub strip, and can be integrated with a rotor containment system. Foams can be integrated with the fan-containment system to provide sufficient safety margins and increased noise attenuation. The major innovation is the integration of the foam with the containment.

  5. Study Acoustic Emissions from Composites

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1997-01-01

    The nondestructive evaluation (NDE) of future propulsion systems utilizing advanced composite structures for the storage of cryogenic fuels, such as liquid hydrogen or oxygen, presents many challenges. Economic justification for these structures requires, light weight, reusable components with an infrastructure allowing periodic evaluation of structural integrity after enduring demanding stresses during operation. A major focus has been placed on the use of acoustic emission NDE to detect propagating defects, in service, necessitating an extensive study into characterizing the nature of acoustic signal propagation at very low temperatures and developing the methodology of applying AE sensors to monitor cryogenic components. This work addresses the question of sensor performance in the cryogenic environment. Problems involving sensor mounting, spectral response and durability are addressed. The results of this work provides a common point of measure from which sensor selection can be made when testing composite components at cryogenic temperatures.

  6. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  7. Evaluation of Acoustic Emission NDE of Composite Crew Module Service Module/Alternate Launch Abort System (CCM SM/ALAS) Test Article Failure Tests

    NASA Technical Reports Server (NTRS)

    Horne, Michael R.; Madaras, Eric I.

    2010-01-01

    Failure tests of CCM SM/ALAS (Composite Crew Module Service Module / Alternate Launch Abort System) composite panels were conducted during July 10, 2008 and July 24, 2008 at Langley Research Center. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests.

  8. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  9. Tecnology innovation related to comfort on commercial vehicles.

    PubMed

    Martini, M; Ferrero, D

    2012-01-01

    The scope of this article is to show the Iveco activity in terms of comfort improvement in all its product Portfolio, focusing on innovation research and realization of tools to get better the life of the driver on commercial vehicles. Comfort related to the ergonomics, thermal, vibrational comfort and after-treatment system in order to improve the life of driver and passengers. It is to remember that Commercial vehicles have different use from a car. For example an heavy truck cabin is not only a place where to drive 8 hours a day, but it is at the same time, an office, a place where to eat, where to sleep and to have a rest. The effort in the last 10 years of Iveco is to improve the comfort of the life of the drivers, utilizing continuous research in standards and innovative systems in order to increase the security and life improvement, focusing also on worldwide legislation as a partner in European committees for health and safety. PMID:23213810

  10. Beyond the Comfort Zone: Lessons of Intercultural Service

    ERIC Educational Resources Information Center

    Urraca, Beatriz; Ledoux, Michael; Harris, James T., III

    2009-01-01

    This article describes an international service-learning project in Bolivia undertaken by faculty and students from Widener University. The authors examine characteristics of the student group, trip preparation, and lessons learned from the experience. The article discusses the American cultural biases that emphasize personal comfort and…

  11. A Series of Computational Neuroscience Labs Increases Comfort with MATLAB.

    PubMed

    Nichols, David F

    2015-01-01

    Computational simulations allow for a low-cost, reliable means to demonstrate complex and often times inaccessible concepts to undergraduates. However, students without prior computer programming training may find working with code-based simulations to be intimidating and distracting. A series of computational neuroscience labs involving the Hodgkin-Huxley equations, an Integrate-and-Fire model, and a Hopfield Memory network were used in an undergraduate neuroscience laboratory component of an introductory level course. Using short focused surveys before and after each lab, student comfort levels were shown to increase drastically from a majority of students being uncomfortable or with neutral feelings about working in the MATLAB environment to a vast majority of students being comfortable working in the environment. Though change was reported within each lab, a series of labs was necessary in order to establish a lasting high level of comfort. Comfort working with code is important as a first step in acquiring computational skills that are required to address many questions within neuroscience.

  12. A Series of Computational Neuroscience Labs Increases Comfort with MATLAB.

    PubMed

    Nichols, David F

    2015-01-01

    Computational simulations allow for a low-cost, reliable means to demonstrate complex and often times inaccessible concepts to undergraduates. However, students without prior computer programming training may find working with code-based simulations to be intimidating and distracting. A series of computational neuroscience labs involving the Hodgkin-Huxley equations, an Integrate-and-Fire model, and a Hopfield Memory network were used in an undergraduate neuroscience laboratory component of an introductory level course. Using short focused surveys before and after each lab, student comfort levels were shown to increase drastically from a majority of students being uncomfortable or with neutral feelings about working in the MATLAB environment to a vast majority of students being comfortable working in the environment. Though change was reported within each lab, a series of labs was necessary in order to establish a lasting high level of comfort. Comfort working with code is important as a first step in acquiring computational skills that are required to address many questions within neuroscience. PMID:26557798

  13. Development of Light Powered Sensor Networks for Thermal Comfort Measurement

    PubMed Central

    Lee, Dasheng

    2008-01-01

    Recent technological advances in wireless communications have enabled easy installation of sensor networks with air conditioning equipment control applications. However, the sensor node power supply, through either power lines or battery power, still presents obstacles to the distribution of the sensing systems. In this study, a novel sensor network, powered by the artificial light, was constructed to achieve wireless power transfer and wireless data communications for thermal comfort measurements. The sensing node integrates an IC-based temperature sensor, a radiation thermometer, a relative humidity sensor, a micro machined flow sensor and a microprocessor for predicting mean vote (PMV) calculation. The 935 MHz band RF module was employed for the wireless data communication with a specific protocol based on a special energy beacon enabled mode capable of achieving zero power consumption during the inactive periods of the nodes. A 5W spotlight, with a dual axis tilt platform, can power the distributed nodes over a distance of up to 5 meters. A special algorithm, the maximum entropy method, was developed to estimate the sensing quantity of climate parameters if the communication module did not receive any response from the distributed nodes within a certain time limit. The light-powered sensor networks were able to gather indoor comfort-sensing index levels in good agreement with the comfort-sensing vote (CSV) preferred by a human being and the experimental results within the environment suggested that the sensing system could be used in air conditioning systems to implement a comfort-optimal control strategy.

  14. Assessing Thermal Comfort of Broiler Chicks During Brooding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper management of the thermal environment during brooding is essential to performance in broilers. Brooding programs used in the broiler industry are prescriptive, but little information exists about thermal comfort in chicks. Identifying thermal conditions that chicks prefer would allow for be...

  15. A novel medical bandage with enhanced clothing comfort

    NASA Astrophysics Data System (ADS)

    Oğlakcioğlu, N.; Sari, B.; Bedez Üte, T.; Marmarali, A.

    2016-07-01

    Compression garments are special textile products which apply a pressure on needed body zones for supporting medical, sport or casual activities. Medical bandages are a group of these garments and they have a very common usage for compression effect on legs or arms. These bandages are generally produced by using synthetic raw materials such as polyamide or polyester fibres. Medical bandages are in contact with skin. Even if the synthetic fibres are used, they may cause both comfort and health problems like allergies. Nowadays in textile sector, the expectations of clients include using of natural fibres as far as possible in all garments. Natural fibres have good advantages such as breathability, softness, moisture management ability, non-allergenic and ecologic structure and these characteristics present optimum utilization conditions. In this study, tubular medical bandages were manufactured by using core spun yarns (sheath fibres are selected as tencel, bamboo and cotton, core material is elastane) and their pressure and comfort (air and water vapour permeability) characteristics were investigated. The results indicated that the bandages have good comfort abilities beside adequate pressure values for compression effect. These garments can constitute a new production field for medical bandages with their comfort properties in addition to pressure characteristics.

  16. Dew Point Evaporative Comfort Cooling: Report and Summary Report

    SciTech Connect

    Dean, J.; Herrmann, L.; Kozubal, E.; Geiger, J.; Eastment, M.; Slayzak, S.

    2012-11-01

    The project objective was to demonstrate the capabilities of the high-performance multi-staged IEC technology and its ability to enhance energy efficiency and interior comfort in dry climates, while substantially reducing electric-peak demand. The project was designed to test 24 cooling units in five commercial building types at Fort Carson Army Base in Colorado Springs, Colorado.

  17. A Series of Computational Neuroscience Labs Increases Comfort with MATLAB

    PubMed Central

    Nichols, David F.

    2015-01-01

    Computational simulations allow for a low-cost, reliable means to demonstrate complex and often times inaccessible concepts to undergraduates. However, students without prior computer programming training may find working with code-based simulations to be intimidating and distracting. A series of computational neuroscience labs involving the Hodgkin-Huxley equations, an Integrate-and-Fire model, and a Hopfield Memory network were used in an undergraduate neuroscience laboratory component of an introductory level course. Using short focused surveys before and after each lab, student comfort levels were shown to increase drastically from a majority of students being uncomfortable or with neutral feelings about working in the MATLAB environment to a vast majority of students being comfortable working in the environment. Though change was reported within each lab, a series of labs was necessary in order to establish a lasting high level of comfort. Comfort working with code is important as a first step in acquiring computational skills that are required to address many questions within neuroscience. PMID:26557798

  18. 24 CFR 3280.511 - Comfort cooling certificate and information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... such air conditioners are rated at 0.3 inch water column static pressure or greater for the cooling air... following shall be supplied in the Comfort Cooling Certificate: Air Conditioner Manufacturer Air Conditioner... Conditioner Manufacturer Certified Capacity ___ BTU/Hr. in accordance with the appropriate Air......

  19. Affordable comfort 95 - investing in our energy future

    SciTech Connect

    1995-12-31

    This report describes the topics from the conference on Affordable Comfort, held March 26-31, 1995. Topics are concerned with energy efficiency in homes, retrofitting, weatherization, and monitoring of appliances, heating, and air conditioning systems for performance, as well as topics on electric utilities.

  20. Two hospitals join forces to sponsor "A Woman's Comfort Day".

    PubMed

    1995-01-01

    Two Baton Rouge, La., hospitals--usually strong competitors--decided to join forces and collaborate on a special event for the women of the community. "A Woman's Comfort Day," now in its third year, was the successful result. If they're feeling good about themselves, can the Super Bowl be far behind?