252 research outputs found

    Improving the quantification of land cover pressure on stream ecological status at the riparian scale using High Spatial Resolution Imagery

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    The aim of this paper is to demonstrate the interest of High Spatial Resolution Imagery (HSRI) and the limits of coarse land cover data such as CORINE Land Cover (CLC), for the accurate characterization of land cover structure along river corridors and of its functional links with freshwater ecological status on a large scale. For this purpose, we compared several spatial indicators built from two land cover maps of the Herault river corridor (southern France): one derived from the CLC database, the other derived from HSRI. The HSRI-derived map was obtained using a supervised object-based classification of multi-source remotely-sensed images (SPOT 5 XS-10 m and aerial photography-0.5 m) and presents an overall accuracy of 70 %. The comparison between the two sets of spatial indicators highlights that the HSRI-derived map allows more accuracy in the quantification of land cover pressures near the stream: the spatial structure of the river landscape is finely resolved and the main attributes of riparian vegetation can be quantified in a reliable way. The next challenge will consist in developing an operational methodology using HSRI for large-scale mapping of river corridor land cover,, for spatial indicator computation and for the development of related pressure/impact models, in order to improve the prediction of stream ecological status

    An OBIA for fine-scale land cover spatial analysis over broad territories: demonstration through riparian corridor and artificial sprawl studies in France

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    International audienceSpatial analysis using fine-scale information over broad territories is essential to define efficient restoration strategies from local to national scale. We designed an OBIA dedicated to produce operationally reliable fine-scale information over broad territories. The originality of our OBIA lies particularly in the top-down approach for the construction of the classification tree and the use of „knowledge-based rules‟ classification technique. The implementation of this OBIA over the two study areas – (i) the Normandy region for riparian area land cover mapping (5600 km² riparian area) and (ii) fours departments over the Languedoc-Roussillon region (22644 km²) – demonstrates the operability of our approach (time-efficient, reproducible, transferable, portable). Broad scale spatial analysis conducted from resulting maps demonstrate the interest of using fine-scale information and highlight that OBIA, following our approach, will be at very short run a broadly applicable method to carry out such analysis

    Sound-Absorption Properties of Materials Made of Esparto Grass Fibers

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    [EN] Research on sound-absorbing materials made of natural fibers is an emerging area in sustainable materials. In this communication, the use of raw esparto grass as an environmentally friendly sound-absorbing material is explored. Measurements of the normal-incidence sound-absorption coefficient and airflow resistivity of three different types of esparto from different countries are presented. In addition, the best-fit coefficients for reasonable prediction of the sound-absorption performance by means of simple empirical formulae are reported. These formulae require only knowledge of the airflow resistivity of the fibrous material. The results presented in this paper are an addition to the characterization of available natural fibers to be used as alternatives to synthetic ones in the manufacturing of sound-absorbing materials.This research was funded by CONICYT-FONDECYT, grant number 1171110.Arenas, JP.; Rey Tormos, RMD.; Alba, J.; Oltra, R. (2020). Sound-Absorption Properties of Materials Made of Esparto Grass Fibers. Sustainability. 12(14):1-10. https://doi.org/10.3390/su12145533S1101214Faruk, O., Bledzki, A. K., Fink, H.-P., & Sain, M. (2012). Biocomposites reinforced with natural fibers: 2000–2010. Progress in Polymer Science, 37(11), 1552-1596. doi:10.1016/j.progpolymsci.2012.04.003Pickering, K. L., Efendy, M. G. A., & Le, T. M. (2016). A review of recent developments in natural fibre composites and their mechanical performance. Composites Part A: Applied Science and Manufacturing, 83, 98-112. doi:10.1016/j.compositesa.2015.08.038Asdrubali, F., Schiavoni, S., & Horoshenkov, K. V. (2012). A Review of Sustainable Materials for Acoustic Applications. Building Acoustics, 19(4), 283-311. doi:10.1260/1351-010x.19.4.283Berardi, U., & Iannace, G. (2015). Acoustic characterization of natural fibers for sound absorption applications. Building and Environment, 94, 840-852. doi:10.1016/j.buildenv.2015.05.029Koruk, H., & Genc, G. (2015). Investigation of the acoustic properties of bio luffa fiber and composite materials. Materials Letters, 157, 166-168. doi:10.1016/j.matlet.2015.05.071Ersoy, S., & Küçük, H. (2009). Investigation of industrial tea-leaf-fibre waste material for its sound absorption properties. Applied Acoustics, 70(1), 215-220. doi:10.1016/j.apacoust.2007.12.005Hosseini Fouladi, M., Nor, M. J. M., Ayub, M., & Leman, Z. A. (2010). Utilization of coir fiber in multilayer acoustic absorption panel. Applied Acoustics, 71(3), 241-249. doi:10.1016/j.apacoust.2009.09.003Hosseini Fouladi, M., Ayub, M., & Jailani Mohd Nor, M. (2011). Analysis of coir fiber acoustical characteristics. Applied Acoustics, 72(1), 35-42. doi:10.1016/j.apacoust.2010.09.007Ramis, J., Del Rey, R., Alba, J., Godinho, L., & Carbajo, J. (2014). A model for acoustic absorbent materials derived from coconut fiber. Materiales de Construcción, 64(313), e008. doi:10.3989/mc.2014.00513Oldham, D. J., Egan, C. A., & Cookson, R. D. (2011). Sustainable acoustic absorbers from the biomass. Applied Acoustics, 72(6), 350-363. doi:10.1016/j.apacoust.2010.12.009Yang, W., & Li, Y. (2012). Sound absorption performance of natural fibers and their composites. Science China Technological Sciences, 55(8), 2278-2283. doi:10.1007/s11431-012-4943-1Tang, X., Zhang, X., Zhang, H., Zhuang, X., & Yan, X. (2018). Corn husk for noise reduction: Robust acoustic absorption and reduced thickness. Applied Acoustics, 134, 60-68. doi:10.1016/j.apacoust.2018.01.012Berardi, U., Iannace, G., & Di Gabriele, M. (2017). The Acoustic Characterization of Broom Fibers. Journal of Natural Fibers, 14(6), 858-863. doi:10.1080/15440478.2017.1279995Lim, Z. Y., Putra, A., Nor, M. J. M., & Yaakob, M. Y. (2018). Sound absorption performance of natural kenaf fibres. Applied Acoustics, 130, 107-114. doi:10.1016/j.apacoust.2017.09.012Malawade, U. A., & Jadhav, M. G. (2020). Investigation of the Acoustic Performance of Bagasse. Journal of Materials Research and Technology, 9(1), 882-889. doi:10.1016/j.jmrt.2019.11.028Gomez, T. S., Navacerrada, M. A., Díaz, C., & Fernández-Morales, P. (2020). Fique fibres as a sustainable material for thermoacoustic conditioning. Applied Acoustics, 164, 107240. doi:10.1016/j.apacoust.2020.107240Othmani, C., Taktak, M., Zein, A., Hentati, T., Elnady, T., Fakhfakh, T., & Haddar, M. (2016). Experimental and theoretical investigation of the acoustic performance of sugarcane wastes based material. Applied Acoustics, 109, 90-96. doi:10.1016/j.apacoust.2016.02.005Or, K. H., Putra, A., & Selamat, M. Z. (2017). Oil palm empty fruit bunch fibres as sustainable acoustic absorber. Applied Acoustics, 119, 9-16. doi:10.1016/j.apacoust.2016.12.002Taban, E., Khavanin, A., Faridan, M., Samaei, S. E., Samimi, K., & Rashidi, R. (2019). Comparison of acoustic absorption characteristics of coir and date palm fibers: experimental and analytical study of green composites. International Journal of Environmental Science and Technology, 17(1), 39-48. doi:10.1007/s13762-019-02304-8Putra, A., Or, K. H., Selamat, M. Z., Nor, M. J. M., Hassan, M. H., & Prasetiyo, I. (2018). Sound absorption of extracted pineapple-leaf fibres. Applied Acoustics, 136, 9-15. doi:10.1016/j.apacoust.2018.01.029Yun, B. Y., Cho, H. M., Kim, Y. U., Lee, S. C., Berardi, U., & Kim, S. (2020). Circular reutilization of coffee waste for sound absorbing panels: A perspective on material recycling. Environmental Research, 184, 109281. doi:10.1016/j.envres.2020.109281Zhang, J., Shen, Y., Jiang, B., & Li, Y. (2018). Sound Absorption Characterization of Natural Materials and Sandwich Structure Composites. Aerospace, 5(3), 75. doi:10.3390/aerospace5030075Kusno, A., Sakagami, K., Okuzono, T., Toyoda, M., Otsuru, T., Mulyadi, R., & Kamil, K. (2019). A Pilot Study on the Sound Absorption Characteristics of Chicken Feathers as an Alternative Sustainable Acoustical Material. Sustainability, 11(5), 1476. doi:10.3390/su11051476Delany, M. E., & Bazley, E. N. (1970). Acoustical properties of fibrous absorbent materials. Applied Acoustics, 3(2), 105-116. doi:10.1016/0003-682x(70)90031-9Berardi, U., & Iannace, G. (2017). Predicting the sound absorption of natural materials: Best-fit inverse laws for the acoustic impedance and the propagation constant. Applied Acoustics, 115, 131-138. doi:10.1016/j.apacoust.2016.08.012Miki, Y. (1990). Acoustical properties of porous materials. Modifications of Delany-Bazley models. Journal of the Acoustical Society of Japan (E), 11(1), 19-24. doi:10.1250/ast.11.19Attenborough, K. (1982). Acoustical characteristics of porous materials. Physics Reports, 82(3), 179-227. doi:10.1016/0370-1573(82)90131-4Dunn, I. P., & Davern, W. A. (1986). Calculation of acoustic impedance of multi-layer absorbers. Applied Acoustics, 19(5), 321-334. doi:10.1016/0003-682x(86)90044-7Garai, M., & Pompoli, F. (2005). A simple empirical model of polyester fibre materials for acoustical applications. Applied Acoustics, 66(12), 1383-1398. doi:10.1016/j.apacoust.2005.04.008Rey, R. del, Alba, J., Arenas, J. P., & Sanchis, V. J. (2012). An empirical modelling of porous sound absorbing materials made of recycled foam. Applied Acoustics, 73(6-7), 604-609. doi:10.1016/j.apacoust.2011.12.009Arenas, J. P., Rebolledo, J., Del Rey, R., & Alba, J. (2014). Sound Absorption Properties of Unbleached Cellulose Loose-Fill Insulation Material. BioResources, 9(4). doi:10.15376/biores.9.4.6227-6240Silva, C. C. B. da, Terashima, F. J. H., Barbieri, N., & Lima, K. F. de. (2019). Sound absorption coefficient assessment of sisal, coconut husk and sugar cane fibers for low frequencies based on three different methods. Applied Acoustics, 156, 92-100. doi:10.1016/j.apacoust.2019.07.001Sair, S., Mansouri, S., Tanane, O., Abboud, Y., & El Bouari, A. (2019). Alfa fiber-polyurethane composite as a thermal and acoustic insulation material for building applications. SN Applied Sciences, 1(7). doi:10.1007/s42452-019-0685-zMaghchiche, A., Haouam, A., & Immirzi, B. (2013). Extraction and Characterization of Algerian Alfa Grass Short Fibers (Stipa Tenacissima). Chemistry & Chemical Technology, 7(3), 339-344. doi:10.23939/chcht07.03.339Nadji, H., Diouf, P. N., Benaboura, A., Bedard, Y., Riedl, B., & Stevanovic, T. (2009). Comparative study of lignins isolated from Alfa grass (Stipa tenacissima L.). Bioresource Technology, 100(14), 3585-3592. doi:10.1016/j.biortech.2009.01.074Belkhir, S., Koubaa, A., Khadhri, A., Ksontini, M., & Smiti, S. (2012). Variations in the morphological characteristics of Stipa tenacissima fiber: The case of Tunisia. Industrial Crops and Products, 37(1), 200-206. doi:10.1016/j.indcrop.2011.11.021Ingard, K. U., & Dear, T. A. (1985). Measurement of acoustic flow resistance. Journal of Sound and Vibration, 103(4), 567-572. doi:10.1016/s0022-460x(85)80024-9Rey, R. del, Alba, J., Arenas, J. P., & Ramis, J. (2013). Technical Notes: Evaluation of Two Alternative Procedures for Measuring Airflow Resistance of Sound Absorbing Materials. Archives of Acoustics, 38(4), 547-554. doi:10.2478/aoa-2013-0064Nelder, J. A., & Mead, R. (1965). A Simplex Method for Function Minimization. The Computer Journal, 7(4), 308-313. doi:10.1093/comjnl/7.4.308Lagarias, J. C., Reeds, J. A., Wright, M. H., & Wright, P. E. (1998). Convergence Properties of the Nelder--Mead Simplex Method in Low Dimensions. SIAM Journal on Optimization, 9(1), 112-147. doi:10.1137/s105262349630347

    Interindividual variability of the modulatory effects of repetitive transcranial magnetic stimulation on cortical excitability

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    Repetitive transcranial magnetic stimulation (rTMS) appears to have effects on cortical excitability that extend beyond the train of rTMS itself. These effects may be inhibitory or facilitatory and appear to depend on the frequency, intensity, duration and intertrain interval of the rTMS. Many studies assume facilitatory effects of high-frequency rTMS and inhibitory effects of low-frequency rTMS. Nevertheless, the interindividual variability of this modulation of cortical excitability by rTMS has not been systematically investigated. In this study, we applied 240 pulses of rTMS at 90% of the subjects' motor threshold to their motor cortex at different frequencies (1, 10, 15 and 20 Hz) and examined the effects on motor evoked potentials (frequency tuning curve). Although the averaged group data showed a frequency-dependent increase in cortical excitability, each subject had a different pattern of frequency tuning curve, i.e. a different modulatory effect on cortical excitability at different rTMS frequencies. The interindividual variability of these modulatory effects was still high, though less so, when the number of rTMS pulses was increased to 1600. These findings illustrate the degree of variability of the rTMS effects in the human brain.Supported in part by grants from the Cellular Science Research Foundation, Yoshida Science Foundation, Japan North America Medical Exchange Foundation, the Stanley Vada Foundation, the National Alliance for Research and Schizophrenia and Depression, and the National Institute of Mental Health (RO1MH57980)Medicin

    An electroacoustic method for measuring airflow resistivity of porous sound-absorbing materials

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    [EN] In this paper, a method for measuring the airflow resistivity of air-saturated porous sound-absorbing materials is presented. The method is based on a modification of the previous device developed by Dragonetti et al. The approach used in the present work involves a cavity and a Helmholtz resonator that are coupled through a loudspeaker so that the complete system behaves as a fourth-order symmetrical band-pass loudspeaker system. After a straightforward calibration, the airflow resistivity of a material sample is indirectly estimated from the direct measurement of the total electric impedance at the loudspeaker connection terminals. In this way, the use of microphones is not necessary, which makes its implementation very simple and inexpensive. Experimental results obtained with the present method agree well with those obtained through a standardized method as long as the values of the material's airflow resistance are not too high. (C) 2019 Elsevier Ltd. All rights reserved.The authors would like to gratefully acknowledge the support of CONICYT-FONDECYT under Grant 1171110 and to the Vicerectorate of R+i+t at Univ. Politecnica of Valencia, Grant PAID0017.Alba, J.; Arenas, JP.; Rey Tormos, RMD.; Rodríguez-Vercher, J. (2019). An electroacoustic method for measuring airflow resistivity of porous sound-absorbing materials. Applied Acoustics. 150:132-137. https://doi.org/10.1016/j.apacoust.2019.02.009S13213715

    Evaluation of two alternative procedures for measuring airflow resistance of sound absorbing materials

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    [EN] It is well known that sound absorption and sound transmission properties of open porous materials are highly dependent on their airflow resistance values. Low values of airflow resistance indicate little resistance for air streaming through the porous material and high values are a sign that most of the pores inside the material are closed. The laboratory procedures for measuring airflow resistance have been stan- dardized by several organizations, including ISO and ASTM for both alternate flow and continuous flow. However, practical implementation of these standardized methods could be both complex and expensive. In this work, two indirect alternative measurement procedures were compared against the alternate flow standardized technique. The techniques were tested using three families of eco-friendly sound absorbent materials: recycled polyurethane foams, coconut natural fibres, and recycled polyester fibres. It is found that the values of airflow resistance measured using both alternative methods are very similar. There is also a good correlation between the values obtained through alternative and standardized methods.This project has been made possible thanks to the FONDECYT Project 1110605 and the grant GV/2012/066 Projects I+D for emerging research groups. The authors would like to thank Dr. Luis Godinho from the Department of Civil Engineering of University of Coimbra (Portugal) for his help with the experimental work and the ISO data reported in Table 1 of this paper.Rey Tormos, RMD.; Alba Fernández, J.; Arenas, JP.; Ramis Soriano, J. (2013). Evaluation of two alternative procedures for measuring airflow resistance of sound absorbing materials. Archives of Acoustics. 38(4):547-554. https://doi.org/10.2478/aoa:2013-0064S54755438

    The Barcelona Brain Health Initiative : Cohort description and first follow-up

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    The Barcelona Brain Health Initiative is a longitudinal cohort study that began in 2017 and aims to understand and characterize the determinants of brain health maintenance in middle aged adults. A cohort of 4686 individuals between the ages of 40 and 65 years free from any neurological or psychiatric diseases was established, and we collected extensive demographic, socio-economic information along with measures of self-perceived health and lifestyles (general health, physical activity, cognitive activity, socialization, sleep, nutrition and vital plan). Here we report on the baseline characteristics of the participants, and the results of the one-year follow-up evaluation. Participants were mainly women, highly educated, and with better lifestyles compared with the general population. After one year 60% of participants completed the one-year follow-up, and these were older, with higher educational level and with better lifestyles in some domains. In the absence of any specific interventions to-date, these participants showed small improvements in physical activity and sleep, but decreased adherence to a Mediterranean diet. These changes were negatively associated with baseline scores, and poorer habits at baseline were predictive of an improvement in lifestyle domains. Of the 2353 participants who completed the one-year follow-up, 73 had been diagnosed with new neurological and neuropsychiatric diseases. Changes in vital plan at follow-up, as well as gender, sleep quality and sense of coherence at baseline were shown to be significant risk factors for the onset of these diagnoses. Notably, gender risk factor decreased in importance as we adjusted by sleep habits, suggesting its potential mediator effects. These findings stress the importance of healthy lifestyles in sustaining brain health, and illustrate the individual benefit that can be derived from participation in longitudinal observational studies. Modifiable lifestyles, specifically quality of sleep, may partially mediate the effect of other risk factors in the development of some neuropsychiatric conditions

    Traumatic brain injury modifies the relationship between physical activity and global and cognitive health : Results from the barcelona brain health initiative

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    Physical activity has many health benefits for individuals with and without history of brain injury. Here, we evaluated in a large cohort study the impact of physical activity on global and cognitive health as measured by the PROMIS global health and NeuroQoL cognitive function questionnaires. A nested case control study assessed the influence of a history of traumatic brain injury (TBI) on the effects of physical activity since underlying pathophysiology and barriers to physical activity in individuals with TBI may mean the effects of physical activity on perceived health outcomes differ compared to the general population. Those with a history of TBI (n = 81) had significantly lower Global health (β = −1.66, p = 0.010) and NeuroQoL cognitive function (β = −2.65, p = 0.006) compared to healthy adults (n = 405). A similar proportion of individuals in both groups reported being active compared to being insufficiently active ((Formula presented.) = 0.519 p = 0.471). Furthermore, the effect of physical activity on global health (β = 0.061, p = 0.076) and particularly for NeuroQoL (β = 0.159, p = 0.002) was greater in those with a history of TBI. Individuals with a history of TBI can adhere to a physically active lifestyle, and if so, that is associated with higher global and cognitive health perceptions. Adhering to a physically active lifestyle is non-trivial, particularly for individuals with TBI, and therefore adapted strategies to increase participation in physical activity is critical for the promotion of public health

    Impact of biodiesel fuel on cold starting of automotive direct injection diesel engines

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    The use of biodiesel fuels in diesel engines is gaining attention as a promising solution to control CO2 emissions. Great research efforts have been carried out to identify the impact of biodiesel physical and chemical properties on engine systems and processes. Most of these investigations were performed in warm conditions, but the suitability of biodiesel for starting the engine at under-zero ambient temperatures has not widely evaluated. The surface tension and the viscosity of biodiesel fuels are higher compared to those of standard diesel and, in cold conditions, these differences become critical since the injection fuel rate is largely affected and consequently the combustion process can be deteriorated. In order to improve its flow characteristics at cold temperatures and make them more suitable for low temperatures operation, additives are used in biodiesel fuels. In this paper the suitability of different biodiesel fuels, with and without additives, for cold starting of DI (direct injection) diesel engines has been evaluated. The results have shown that the engine start-ability with pure biodiesel fuels can be largely deteriorated. However, using diesel/biodiesel blends the start-ability of the engine can be recovered with the additional benefit of reducing the opacity peak of the exhaust gasesBroatch Jacobi, JA.; Tormos Martínez, BV.; Olmeda González, PC.; Novella Rosa, R. (2014). Impact of biodiesel fuel on cold starting of automotive direct injection diesel engines. Energy. 73:653-660. doi:10.1016/j.energy.2014.06.062S6536607

    The Barcelona Brain Health Initiative: A Cohort Study to Define and Promote Determinants of Brain Health

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    The Barcelona Brain Health Initiative (BBHI) is an ongoing prospective longitudinal study focused on identifying determinants of brain health. The main objectives are: (i) to characterize lifestyle, cognitive, behavioral and environmental markers related to a given individual’s cognitive and mental functions in middle to old age, (ii) to assess the biological determinants predictive of maintenance of brain health, and (iii) to evaluate the impact of a controlled multi-dimensional lifestyle intervention on improving and maintaining brain health. The BBHI cohort consists of >4500 healthy participants aged 40–65 years followed through online questionnaires (Phase I) assessing participants’ self-perceived health and lifestyle factors in seven different domains: overall health, physical exercise, cognitive activity, sleep, nutrition, social interactions, and life purpose. In Phase II a sub-group of 1,000 individuals is undergoing detailed in-person evaluations repeated at two-yearly intervals. These evaluations will provide deep phenotyping of brain function, including medical, neurological and psychiatric examinations, assessment of physical fitness, neuropsychological assessments, structural and functional brain magnetic resonance imaging, electroencephalography and perturbation-based non-invasive brain stimulation evaluations of brain activity, as well as collection of biological samples. Finally, in Phase III a further sub-group of 500 participants will undergo a similar in-person assessment before and after a multi-dimensional intervention to optimize lifestyle habits and evaluate its effects on cognitive and brain structure and function. The intervention group will receive remote supervision through an ICT-based solution, with the support of an expert in health and lifestyle coaching strategies aimed at promoting adherence. On the other hand, the control group will not have this coaching support, and will only receive education and recommendations about healthy habits. Results of this three-part initiative shall critically contribute to a better understanding of the determinants to promote and maintain brain health over the lifespan
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