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1
Lai, D. Y. F., N. T. Roulet, E. R. Humphreys, T. R. Moore, and M. Dalva. "The effect of atmospheric turbulence and chamber deployment period on autochamber CO<sub>2</sub> and CH<sub>4</sub> flux measurements in an ombrotrophic peatland." Biogeosciences 9, no. 8 (August 24, 2012): 3305–22. http://dx.doi.org/10.5194/bg-9-3305-2012.
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Abstract. Accurate quantification of soil-atmosphere gas exchange is essential for understanding the magnitude and controls of greenhouse gas emissions. We used an automatic, closed, dynamic chamber system to measure the fluxes of CO2 and CH4 for several years at the ombrotrophic Mer Bleue peatland near Ottawa, Canada and found that atmospheric turbulence and chamber deployment period had a considerable influence on the observed flux rates. With a short deployment period of 2.5 min, CH4 flux exhibited strong diel patterns and both CH4 and nighttime CO2 effluxes were highly and negatively correlated with ambient friction velocity as were the CO2 concentration gradients in the top 20 cm of peat. This suggests winds were flushing the very porous and relatively dry near-surface peat layers and reducing the belowground gas concentration gradient, which then led to flux underestimations owing to a decrease in turbulence inside the headspace during chamber deployment compared to the ambient windy conditions. We found a 9 to 57% underestimate of the net biological CH4 flux at any time of day and a 13 to 21% underestimate of nighttime CO2 effluxes in highly turbulent conditions. Conversely, there was evidence of an overestimation of ~ 100% of net biological CH4 and nighttime CO2 fluxes in calm atmospheric conditions possibly due to enhanced near-surface gas concentration gradient by mixing of chamber headspace air by fans. These problems were resolved by extending the deployment period to 30 min. After 13 min of chamber closure, the flux rate of CH4 and nighttime CO2 became constant and were not affected by turbulence thereafter, yielding a reliable estimate of the net biological fluxes. The measurement biases we observed likely exist to some extent in all chamber flux measurements made on porous and aerated substrate, such as peatlands, organic soils in tundra and forests, and snow-covered surfaces, but would be difficult to detect unless high frequency, semi-continuous observations were made.
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Lai, D. Y. F., N. T. Roulet, E. R. Humphreys, T. R. Moore, and M. Dalva. "The effect of atmospheric turbulence and chamber deployment period on autochamber CO<sub>2</sub> and CH<sub>4</sub> flux measurements in an ombrotrophic peatland." Biogeosciences Discussions 9, no. 2 (February 1, 2012): 1439–82. http://dx.doi.org/10.5194/bgd-9-1439-2012.
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Abstract. Accurate quantification of soil-atmosphere gas exchange is essential for understanding the magnitude and controls of greenhouse gas emissions. We used an automatic closed dynamic chamber system to measure the fluxes of CO2 and CH4 for several years at the ombrotrophic Mer Bleue peatland near Ottawa, Canada and found that atmospheric turbulence and chamber deployment period had a considerable influence on the observed flux rates. With a short deployment period of 2.5 min, CH4 flux exhibited strong diel patterns and both CH4 and nighttime CO2 effluxes were highly and negatively correlated with friction velocity as were the CO2 concentration gradients in the top 20 cm of peat. This suggests winds were flushing the very porous and relatively dry near surface peat layers, altering the concentration gradient and resulting in a 9 to 57% underestimate of CH4 flux at any time of day and a 13 to 21% underestimate of nighttime CO2 fluxes in highly turbulent conditions. Conversely, there was evidence of an overestimation of ~100% of CH4 and nighttime CO2 effluxes in calm atmospheric conditions possibly due to enhanced near-surface gas concentration gradient by mixing of chamber headspace air by fans. These problems were resolved by extending the deployment period to 30 min. After 13 min of chamber closure, the flux rate of CH4 and nighttime CO2 became constant and were not affected by turbulence thereafter, yielding a reliable estimate of the net biological fluxes. The measurement biases we observed likely exist to some extent in all chamber flux measurements made on porous and aerated substrate, such as peatlands, organic soils in tundra and forests, and snow-covered surfaces, but would be difficult to detect unless high frequency, semi-continuous observations are made.
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Schäfer, K., R. H. Grant, S. Emeis, A. Raabe, C. von der Heide, and H. P. Schmid. "Areal-averaged trace gas emission rates from long-range open-path measurements in stable boundary layer conditions." Atmospheric Measurement Techniques Discussions 5, no. 1 (February 13, 2012): 1459–96. http://dx.doi.org/10.5194/amtd-5-1459-2012.
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Abstract. Measurements of land-surface emission rates of greenhouse and other gases at large spatial scales (10 000 m2) are needed to assess the spatial distribution of emissions. This can be more readily done using spatial-integrating micro-meteorological methods than the widely-utilized small chamber measurements. Several micro-meteorological flux-gradient methods utilizing a non-intrusive path-averaging measurement method were evaluated for determining land-surface emission rates of trace gases under stable boundary layers. Successful application of a flux-gradient method requires confidence in the gradients of trace gas concentration and wind and in the applicability of boundary-layer turbulence theory. While there is relatively high confidence in flux measurements made under unstable atmospheres with mean winds greater than 1 m s−1, there is greater uncertainty in flux measurements made under free convective or stable conditions. The study involved quality-assured determinations of fluxes under low wind, stable or night-time atmospheric conditions when the continuous "steady-state" turbulence of the surface boundary layer breaks down and the layer has intermittent turbulence. Results indicate that the Monin-Obukhov similarity theory (MOST) flux-gradient methods that assume a log-linear profile of the wind speed and concentration gradient incorrectly determine vertical profiles and thus fluxes in the stable boundary layer.
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Grant, Richard H., and Rex A. Omonode. "Estimation of nocturnal CO<sub>2</sub> and N<sub>2</sub>O soil emissions from changes in surface boundary layer mass storage." Atmospheric Measurement Techniques 11, no. 4 (April 12, 2018): 2119–33. http://dx.doi.org/10.5194/amt-11-2119-2018.
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Abstract. Annual budgets of greenhouse and other trace gases require knowledge of the emissions throughout the year. Unfortunately, emissions into the surface boundary layer during stable, calm nocturnal periods are not measurable using most micrometeorological methods due to non-stationarity and uncoupled flow. However, during nocturnal periods with very light winds, carbon dioxide (CO2) and nitrous oxide (N2O) frequently accumulate near the surface and this mass accumulation can be used to determine emissions. Gas concentrations were measured at four heights (one within and three above canopy) and turbulence was measured at three heights above a mature 2.5 m maize canopy from 23 July to 10 September 2015. Nocturnal CO2 and N2O fluxes from the canopy were determined using the accumulation of mass within a 6.3 m control volume and out the top of the control volume within the nocturnal surface boundary layer. Diffusive fluxes were estimated by flux gradient method. The total accumulative and diffusive fluxes during near-calm nights (friction velocities < 0.05 ms−1) averaged 1.16 µmol m−2 s−1 CO2 and 0.53 nmol m−2 s−1 N2O. Fluxes were also measured using chambers. Daily mean CO2 fluxes determined by the accumulation method were 90 to 130 % of those determined using soil chambers. Daily mean N2O fluxes determined by the accumulation method were 60 to 80 % of that determined using soil chambers. The better signal-to-noise ratios of the chamber method for CO2 over N2O, non-stationary flow, assumed Schmidt numbers, and anemometer tilt were likely contributing reasons for the differences in chambers versus accumulated nocturnal mass flux estimates. Near-surface N2O accumulative flux measurements in more homogeneous regions and with greater depth are needed to confirm the conclusion that mass accumulation can be effectively used to estimate soil emissions during nearly calm nights.
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Rickards, Guy. "MARGARET BROUWER, CHEN YI, SADIE HARRISON, MISATO MOCHIZUKI, ONUTE NARBUTAITE, APPARENZE." Tempo 58, no. 229 (July 2004): 60–66. http://dx.doi.org/10.1017/s0040298204360225.
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MARGARET BROUWER: Lament for violin, clarinet, bassoon and percussion12,4,6,10; Light for soprano, harpsichord, flute, clarinet, violin, cello and percussion1,7,2,5,13,14,11; Under the Summertree for piano8; Skyriding for flute, violin, cello & piano3,13,14,9; Demeter Prelude for string quartet15. 1Sandra Simon (sop), 2Sean Gabriel (fl), 3Alice Kogan Weinreb (fl), 4Jean Kopperud (cl), 5Amitai Vardi (cl), 6Donald McGeen (bsn), 7Jeanette Sorrell (hpschd), 8Kathryn Brown (pno), 9Mitsuko Morikawa (pno), 10Dominic Donato (perc), 11Scott Christian (perc), 12Laura Frautschi (vln), 13Gabriel Bolkosky (vln), 14Ida Mercer (vlc), 15Cavani String Quartet. New World 80606-2.CHEN YI: Momentum; Chinese Folk Dance Suite for violin and orchestra1; Dunhuang Fantasy for organ and chamber wind ensemble3; Romance and Dance for 2 violins and string orchestra1,2; Tu. 1Cho-Liang Lin (vln), 2Yi-Jia Susanne Hou (vln), 3Kimberley Marshall (org), Singapore SO c. Lan Shui. BIS-CD-1352.SADIE HARRISON: The Light Garden for mixed quintet1; The Fourteenth Terrace for clarinet and ensemble2; Bavad Khair Baqi! for solo violin3. Traditional Afghan Music4. 1Tate Ensemble, 2Andrew Spalding (cl), Lontano c. Odaline de la Martinez, 3Peter Sheppard Skærved (vln), 4Ensemble Bakhtar. Metier MSV CD92084.MISATO MOCHIZUKI: Si bleu, si calme1; All that is including me for bass flute, clarinet and violin1,2,3; Chimera; Intermezzi I for flute & piano1,4; La chamber claire. 1Eva Furrer (fl, bass fl), 2Bernhard Zachhuber (cl), 3Sophie Schafleitner (vln), 4Marino Formenti (pno), Klangforum Wien c. Johannes Kalitzke. Kairos 0012402KAIONUTE NARBUTAITE: Symphony No. 2; Liberatio for 12 winds, cymbals & 4 strings; Metabole for chamber orchestra. Lithuanian National SO c.Robertas Fervenikas. Finlandia 0927-49597-2.ALLA PAVLOVA: Symphony No. 1, Farewell Russia1,3,4; Symphony No.32,3,5. 1Leonid Lebedev (fl), Nikolay Lotakov (picc), Mikhail Shestakov (vln), Valery Brill (vlc), Mikhail Adamovich (pno); 2Olga Verdernikova (vln), 3Russian PO c. 4Konstantin D. Krimets, 5Alexander Vedernikov. Naxos 8.557157.‘APPARENZE: Collana di Nuove Musiche 1997’. Works by SILVIA DELITALA, RITA PORTERA, CATERINA DE CARLO, BEATRICE CAMPODONICO, PAOLA CIAR-LANTINI, JANET MAGUIRE, MARCO SANTAM BROGIO, PAOLO MINETTI, FEDERICO MONTAGNER, RINALDO BELLUCCI and BIAGIO PUTIGNANO. Maria Vittoria Vallese (sop), Pia Zanca, Fiametta Facchini, Rinaldo Bellucci (pnos), Duo Soncini-Flückiger, Italian Guitar Quartet, Ensemble Paul Klee, Fabrizio Fantini, Gianluca Calonghi (cls), Giuseppe Giannotti (ob). Radio Onda d'Urto E.F.B 001.
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Evans, W. G., and R. H. Gooding. "Turbulent plumes of heat, moist heat, and carbon dioxide elicit upwind anemotaxis in tsetse flies Glossina morsitans morsitans Westwood (Diptera: Glossinidae)." Canadian Journal of Zoology 80, no. 7 (July 1, 2002): 1149–55. http://dx.doi.org/10.1139/z02-101.
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The roles and interactions of turbulent plumes of heat, moist heat, and carbon dioxide in mediating upwind flight of adult tsetse flies (Glossina morsitans morsitans Westwood) were investigated using a wind tunnel in a constant-environment chamber. Heat fluctuations in the plume that were detected by a thermocouple and displayed as oscilloscope traces allowed direct visualization of the structures of the plumes. Significantly more flies flew upwind when exposed to plumes of (i) carbon dioxide (0.0051% above background) and air (58% relative humidity) compared with air alone; (ii) carbon dioxide and heated air (35% relative humidity and temperature fluctuating up to 0.09°C above background) compared with carbon dioxide and air; and (iii) carbon dioxide and moist (82% relative humidity) heated air (temperature fluctuating up to 0.05°C above background) compared with carbon dioxide and heated air. However, there were no significant differences in upwind flight of flies exposed to plumes of (i) air compared with humidified air (65% relative humidity); (ii) carbon dioxide and heated air compared with heated air alone; and (iii) carbon dioxide and moist heated air compared with moist heated air alone. Recorded temperature fluctuations in heat plumes transported downwind from a tethered steer in a pasture showed patterns similar to those produced in the wind-tunnel plumes. These results suggest that host emissions of carbon dioxide alone and combined heat and moisture carried downwind by low-velocity winds elicit upwind anemotaxis in tsetse flies, which distinguish these emissions from a background of lower atmospheric levels.
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Shantz, N. C., R. Y. W. Chang, J. G. Slowik, J. P. D. Abbatt, and W. R. Leaitch. "Slower CCN growth kinetics of anthropogenic aerosol compared to biogenic aerosol observed at a rural site." Atmospheric Chemistry and Physics Discussions 9, no. 3 (June 23, 2009): 13775–99. http://dx.doi.org/10.5194/acpd-9-13775-2009.
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Abstract. Growth rates of water droplets were measured with a static diffusion cloud condensation chamber in May–June 2007 at a rural field site in Southern Ontario, Canada, 70 km north of Toronto. Observations were made during periods when the winds were from the south and the site was impacted by anthropogenic air from the US and Southern Ontario as well as during a 5-day period of northerly wind flow when the aerosol was dominated by biogenic sources. The growth of droplets on anthropogenic size-selected particles centred at 0.1 μm diameter and composed of approximately 40% organic and 60% ammonium sulphate (AS) by mass, was delayed on the order of 1 second compared to a pure AS aerosol. Simulations of the growth rate indicate that a lowering of the water mass accommodation coefficient from αc=1 to an average of αc=0.044 is needed (assuming an insoluble organic with hygroscopicity parameter, κorg, of zero). In contrast, the growth rate of the aerosol of biogenic character, consisting of >80% organic, was similar to that of pure AS. Simulations of the predominantly biogenic aerosol show agreement between the observations and simulations when κorg=0.05–0.2 and αc=1. Inhibition of water uptake by the anthropogenic organic applied to an adiabatic cloud parcel model in the form of a constant low αc increases the number of droplets in a cloud compared to pure AS. If the αc is assumed to increase with increasing liquid water on the droplets, then the number of droplets decreases which could diminish the indirect effect. The slightly lower κorg in the biogenic case decreases the number of droplets in a cloud compared to pure AS.
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O'Loughlin, Niall. "Wind Chamber." Musical Times 129, no. 1742 (April 1988): 193. http://dx.doi.org/10.2307/965323.
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Klein, Lorin. "Unique Test Capabilities of the Eglin AFB McKinley Climatic Laboratory." Journal of the IEST 30, no. 6 (November 1, 1987): 27–29. http://dx.doi.org/10.17764/jiet.1.30.6.l3663m6017674334.
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The 92,900m3 (3.28 million ft3) Main Chamber of the Climatic Laboratory (Figure 1) is the largest and most complex climatic environmental test chamber in the world. It employs an air makeup system to cool or heat air to the test temperatures and ingest this air into the chamber to allow the operation of jet engines during climatic tests. Other test chambers discussed are the 2,750 m3 (97,000 ft3) Engine and Equipment Test Facility and the 2,125 m3 (75,000 ft3) Sun, Wind, Rain, and Dust Facility.
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Shantz, N. C., R. Y. W. Chang, J. G. Slowik, A. Vlasenko, J. P. D. Abbatt, and W. R. Leaitch. "Slower CCN growth kinetics of anthropogenic aerosol compared to biogenic aerosol observed at a rural site." Atmospheric Chemistry and Physics 10, no. 1 (January 15, 2010): 299–312. http://dx.doi.org/10.5194/acp-10-299-2010.
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Abstract. Growth rates of water droplets were measured with a static diffusion cloud condensation chamber in May–June 2007 at a rural field site in Southern Ontario, Canada, 70 km north of Toronto. The observations include periods when the winds were from the south and the site was impacted by anthropogenic air from the U.S. and Southern Ontario as well as during a 5-day period of northerly wind flow when the aerosol was dominated by biogenic sources. The growth of droplets on anthropogenic size-selected particles centred at 0.1 μm diameter and composed of approximately 40% organic and 60% ammonium sulphate (AS) by mass, was delayed by on the order of 1 s compared to a pure AS aerosol. Simulations of the growth rate on monodisperse particles indicate that a lowering of the water mass accommodation coefficient from αc=1 to an average of αc=0.04 is needed (assuming an insoluble organic with hygroscopicity parameter, κorg, of zero). Simulations of the initial growth rate on polydisperse anthropogenic particles agree best with observations for αc=0.07. In contrast, the growth rate of droplets on size-selected aerosol of biogenic character, consisting of >80% organic, was similar to that of pure AS. Simulations of the predominantly biogenic polydisperse aerosol show agreement between the observations and simulations when κorg=0.2 (with upper and lower limits of 0.5 and 0.07, respectively) and αc=1. Inhibition of water uptake by the anthropogenic organic applied to an adiabatic cloud parcel model in the form of a constant low αc increases the number of droplets in a cloud compared to pure AS. If the αc is assumed to increase with increasing liquid water on the droplets, then the number of droplets decreases which could diminish the indirect climate forcing effect. The slightly lower κorg in the biogenic case decreases the number of droplets in a cloud compared to pure AS.
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O'Loughlin, Niall. "Modern Wind Chamber." Musical Times 128, no. 1733 (July 1987): 392. http://dx.doi.org/10.2307/964543.
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Glockling, Sally L., and Gordon W. Beakes. "The ultrastructure of the dimorphic infection cells of Haptoglossa heteromorpha illustrates the developmental plasticity of infection apparatus structures in a nematode parasite." Canadian Journal of Botany 78, no. 8 (August 1, 2000): 1095–107. http://dx.doi.org/10.1139/b00-074.
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The nematophagous fungus Haptoglossa heteromorpha Glockling & Beakes is unusual in this genus, as it consistently produces two morphologically distinct infection cells that develop respectively from the large and small aplanospores. The large infection cells are typical "gun cells" and are uninucleate with over half the cytoplasmic volume occupied by the basal vacuole. However, the small infection cells are considerably modified in their structure. They have an elongate tapered morphology with a bilobed base. Small infection cells are binucleate and contain both apical and basal vacuolar regions. The inverted injection tube is highly modified and originates at a raised padlike region on the mid ventral side of the cell. This protruding pad is associated with a diffuse covering of fibrillar material. The bore region extends deep into the cell and the highly compressed missile chamber is located beneath the hindmost nucleus, near the base of the cell. Finally, there is a more typical tube tail segment, which winds between the nuclei and eventually terminates beneath the anterior vacuole. The differences with gun cells of previously described Haptoglossa species are documented. The functional and biological significance of these two different infection cells is discussed. Only the large gun cells were observed to discharge to form sporidia. It seems unlikely that the highly modified smaller cells can infect in this way. It may be that the two different cell types have evolved to infect different hosts, but no direct confirmation of this could be obtained.Key words: Haptoglossa, host-parasite interactions, infection (gun) cell, nematophagous fungi, ultrastructure.
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Smith, E., R. Gordon, C. Bourque, and A. Campbell. "Comparison of three simple field methods for ammonia volatilization from manure." Canadian Journal of Soil Science 87, no. 4 (August 1, 2007): 469–77. http://dx.doi.org/10.4141/cjss06038.
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Land application of swine manure can result in a loss of nitrogen (N) through ammonia (NH3) volatilization. Accurate NH3 loss assessments are essential to support the development of regional and global emission factors and identify best management strategies for reducing losses. The objectives of this study were to simultaneously assess the reliability and applicability of three simple NH3 flux measurement techniques and their effectiveness and usefulness for the measurement of emissions from surface-applied swine manure. Ammonia losses from two chamber systems were compared: (i) static and (ii) wind tunnel chamber, as well as the (iii) micrometeorological theoretical profile shape (TPS) method. A series of field tests was performed at the Agriculture and Agri-Food Canada (AAFC) Research Farm in Harrington, Prince Edward Island (PE) on a sandy loam, stubble field that was surface applied with 100 kg NH4-N ha-1 of liquid swine manure. After application the three NH3 emission techniques were established and measurements were performed over a 5-d period. Ammonia losses from the wind tunnels were comparable with those from the TPS method. The static chambers were found to underestimate NH3 emissions (by ~95–99%), compared with both the wind tunnel and TPS methods. It is therefore recommended that either the TPS or wind tunnel approaches be used to more accurately quantify NH3 losses for field systems. Key words: Ammonia volatilization, flux measurements, swine manure, micrometeorology, static chambers, wind tunnel
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Ruiz-Bejarano, M. Jesús, Enrique Durán-Guerrero, Remedios Castro, Carmelo G. Barroso, and M. Carmen Rodríguez-Dodero. "Use of Sensory Analysis to Investigate the Influence of Climate Chambers and Other Process Variables in the Production of Sweet Wines." Foods 9, no. 4 (April 3, 2020): 424. http://dx.doi.org/10.3390/foods9040424.
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In this study, a climate chamber, as an alternative method, has been used to dry raisins and the sensory profiles of the sweet sherry wines obtained have been evaluated. Other important factors, namely grape variety, vintage, vinification conditions, as well as the ageing method and its length of time, have also been considered. When heavy rainfall had been registered, the musts extracted from grapes dried under controlled conditions in a climate chamber showed a lower intensity of the musty off-odor compared to those elaborated with sun-dried grapes. The wine fermented at low temperature with Saccharomyces bayanus scored the highest in citric and floral notes, and this was preferred over all the other wines that were evaluated. The wines aged in oak barrels were preferred to both, wines aged in the presence of oak chips as well as those aged without any wood contact. The use of climate chambers to dry the grapes that are going to be used for the elaboration of sweet wines appears to be an advantageous alternative to the traditional method, since it allows a more precise control of the process and highly valued sweet wines from a sensory point of view are obtained thereby.
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Saltykova, Marina M., I. P. Bobrovnitskii, M. Yu Yakovlev, A. D. Banchenko, and S. N. Nagornev. "A NEW APPROACH TO THE ANALYSIS OF THE INFLUENCE OF WEATHER CONDITIONS ON THE HUMAN ORGANISM." Hygiene and sanitation 97, no. 11 (November 15, 2018): 1038–42. http://dx.doi.org/10.18821/0016-9900-2018-97-11-1038-42.
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Despite the long history of studying the influence of meteo- and heliogeophysical factors on the human body, the mechanisms of this influence remain unclear. The inability to influence weather conditions makes it necessary to develop new, experimental approaches to such research. To analyze the effect of the ambient air temperature, atmospheric pressure, moisture and other meteorological indices on the human body, and to identify the mechanisms of such impact, there is proposed a new approach using an appropriate experimental stand (weather experimental stand). The basis of such stand can be composed of a climatic chamber, the technical characteristics of which allow carrying out research with human participation. In such studies, various physiological and biochemical indices can be monitored, as well as psychological tests can be administered. Such studies are of particular relevance in relation to the intensive development of the Arctic since in high latitudes the influence of heliogeophysical and meteorological factors is very pronounced. The climate of the Arctic is characterized by a combination of significant temperature fluctuations, atmospheric pressure, low absolute and high relative humidity, strong winds, significant changes in the geomagnetic field and atmospheric electricity, a pronounced deficit of UV radiation and light aperiodicity. Features of the natural conditions of the North, apparently, cause a high incidence of the diseases of the circulatory and respiratory system in the alien population (in comparison with the indigenous one). In addition, the article draws attention to the fact that the only weather factor, whose mechanisms of influence are sufficiently well studied, is the change in ambient air temperature, and these mechanisms were studied through research done under experimental conditions.
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Graczykowski, Cezary, and Jan Holnicki-Szulc. "Protecting Offshore Wind Turbines against Ship Impacts by Means of Adaptive Inflatable Structures." Shock and Vibration 16, no. 4 (2009): 335–53. http://dx.doi.org/10.1155/2009/725969.
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Collisions with small service ships are serious danger for offshore wind turbines. Installing torus-shaped adaptive inflatable structure that surrounds a wind turbine tower at water level is one method of effective protection. Proposed pneumatic structure contains several separate air chambers equipped with devices for fast inflation and pressure release. The system can be adapted to various impact scenarios by adjusting the level of initial pressure in each chamber and by controlling the release of compressed air during collision. The paper presents finite element simulation of ship collision with wind turbine tower protected by pneumatic structure, conducted using ABAQUS software. Introduced methods of pressure adjustment are aimed at mitigating tower and ship response. The performed feasibility study proves that inflatable structure can effectively protect the wind turbine tower and the ship against serious damage.
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Law, Cliff S., Murray J. Smith, Mike J. Harvey, Thomas G. Bell, Luke T. Cravigan, Fiona C. Elliott, Sarah J. Lawson, et al. "Overview and preliminary results of the Surface Ocean Aerosol Production (SOAP) campaign." Atmospheric Chemistry and Physics 17, no. 22 (November 16, 2017): 13645–67. http://dx.doi.org/10.5194/acp-17-13645-2017.
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Abstract. Establishing the relationship between marine boundary layer (MBL) aerosols and surface water biogeochemistry is required to understand aerosol and cloud production processes over the remote ocean and represent them more accurately in earth system models and global climate projections. This was addressed by the SOAP (Surface Ocean Aerosol Production) campaign, which examined air–sea interaction over biologically productive frontal waters east of New Zealand. This overview details the objectives, regional context, sampling strategy and provisional findings of a pilot study, PreSOAP, in austral summer 2011 and the following SOAP voyage in late austral summer 2012. Both voyages characterized surface water and MBL composition in three phytoplankton blooms of differing species composition and biogeochemistry, with significant regional correlation observed between chlorophyll a and DMSsw. Surface seawater dimethylsulfide (DMSsw) and associated air–sea DMS flux showed spatial variation during the SOAP voyage, with maxima of 25 nmol L−1 and 100 µmol m−2 d−1, respectively, recorded in a dinoflagellate bloom. Inclusion of SOAP data in a regional DMSsw compilation indicates that the current climatological mean is an underestimate for this region of the southwest Pacific. Estimation of the DMS gas transfer velocity (kDMS) by independent techniques of eddy covariance and gradient flux showed good agreement, although both exhibited periodic deviations from model estimates. Flux anomalies were related to surface warming and sea surface microlayer enrichment and also reflected the heterogeneous distribution of DMSsw and the associated flux footprint. Other aerosol precursors measured included the halides and various volatile organic carbon compounds, with first measurements of the short-lived gases glyoxal and methylglyoxal in pristine Southern Ocean marine air indicating an unidentified local source. The application of a real-time clean sector, contaminant markers and a common aerosol inlet facilitated multi-sensor measurement of uncontaminated air. Aerosol characterization identified variable Aitken mode and consistent submicron-sized accumulation and coarse modes. Submicron aerosol mass was dominated by secondary particles containing ammonium sulfate/bisulfate under light winds, with an increase in sea salt under higher wind speeds. MBL measurements and chamber experiments identified a significant organic component in primary and secondary aerosols. Comparison of SOAP aerosol number and size distributions reveals an underprediction in GLOMAP (GLObal Model of Aerosol Processes)-mode aerosol number in clean marine air masses, suggesting a missing marine aerosol source in the model. The SOAP data will be further examined for evidence of nucleation events and also to identify relationships between MBL composition and surface ocean biogeochemistry that may provide potential proxies for aerosol precursors and production.
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Si, Chao Wei, Guo Wei Han, Jin Ning, Wei Wei Zhong, and Fu Hua Yang. "Design of a MEMS Resonant Wind Sensor on Airplane Wing." Key Engineering Materials 562-565 (July 2013): 436–40. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.436.
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A new kind of wind sensor made up of MEMS resonators is designed in the paper capable of sensing the lift, the resistance and the turbulence of airplane wings by mounting on the surface. The designed wind sensor is made up of four MEMS wind pressure gauges fixed around a square wind resistance block which used to block the wind to change the wind pressure on the surface, and the change of wind pressure is detected by MEMS wind pressure gauges to reveal the air condition on the surface of the airplane wings. As known, a MEMS resonator is a second-order resonant system whose damping factor is mainly dependent on the air pressure, and the characteristic is often used to detecting the airtightness of a sealed chamber for the damping factor is sensitive under high vacuum, while a MEMS resonator with the damping factor sensitive at atmospheric pressure is designed in this paper for sensing wind pressure change, and the MEMS resonator is manufactured on SOI substrates with deep reactive ion etching technology. Also relations between the wind pressure change and the wind speed around a block at atmosphere is revealed by finite element simulation. Compared to traditional wind sensors such as anemometers and Venturi tubes, the designed MEMS wind sensor with a very small size is suitable to mount on different zones of a wing with a large amount to monitor the air condition and have less influence on air flow.
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Maier, Martin, Samuel Mayer, and Thomas Laemmel. "Rain and wind affect chamber measurements." Agricultural and Forest Meteorology 279 (December 2019): 107754. http://dx.doi.org/10.1016/j.agrformet.2019.107754.
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Zajdel, Barbara, Monika Fliszkiewicz, Kornelia Kucharska, and Jakub Gąbka. "Influence of the presence of Cacoxenus indagator Loew. parasite larvae in brood chambers on the emergence rate and size of red mason bees." Medycyna Weterynaryjna 72, no. 9 (2016): 567–70. http://dx.doi.org/10.21521/mw.5559.
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Cacoxenus indagator is one of cleptoparasites most frequently found in the nests of Osmia bicornis L. The goal of this experiment was to examine the influence of the presence of 2-3 C. indagator larvae in the brood chamber on the cocoon mass, on the mass and size of bee imagines, and on their emergence rate. During the analysis of red mason bee nest material, 200 cocoons were taken from brood chambers, each of them also containing 2-3 larvae of C. indagator (CC). The control group consisted of 200 randomly chosen cocoons from brood chambers with no parasites inside (CFFC). The cocoons and the emerged bees were weighed, and then the size of the bees was determined by the microscope image analysis software Axio Vision Rel. 4.0 coupled with a Stereo Lumar V12 stereoscopic microscope (Carl Zeiss, Germany). This involved measuring the sum of the widths of tergites 3 and 4, the distance between the wings and the forewing length and width. It was found that the presence of 2-3 C. indagator larvae in the brood chamber had no impact on the mortality of bees in cocoons. The research demonstrates that CC cocoons do not have to be removed when collecting cocoons from artificial nests in managed O. bicornis populations, as bees emerging from such cocoons are fully developed.
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Daems, David, Antoine Tilmans, Timo De Mets, and Xavier Loncour. "Design of an advanced hot box-cold box with full climatic control to test heat, air and moisture transport through real scale building elements." E3S Web of Conferences 172 (2020): 19008. http://dx.doi.org/10.1051/e3sconf/202017219008.
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A versatile hot box-cold box test facility called HAMSTER enables to evaluate the energy and hygrothermal performance of up to 3m high, 3m wide and 3.6m deep building test elements including walls, flat or pitched roofs and floors. This equipment allows for the precise measurement of thermal performance according to standards. It also allows for the study of heat, air and moisture phenomena taking place in building elements under realistic climatic conditions including the effects of rain, sun or wind. Interior and exterior climates are simulated in, respectively, the hot and cold chambers by controlling the temperature, relative humidity, pressure difference between both chambers, infra-red or solar simulator heating and water spraying in the cold chamber. Critical issues that have been solved during the design and construction phases in order to reach both the required performances and the versatility of the test facility are discussed.
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He, Xue Feng, Yi Fu Fang, and Zhi Gang Du. "Effects of Geometrical Parameters on Performances of Wind Energy Harvester with a Chamber." Key Engineering Materials 562-565 (July 2013): 1075–79. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.1075.
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To improve the performances under low speed wind, a wind energy harvester similar to harmonicas was proposed. The harvester mainly includes a cuboid chamber and a cantilevered beam. The front wall of the chamber is opened as the air entrance and a rectangular hole is opened on the sidewall as the exit. The cantilever composed of a piezoelectric sheet and a flexible beam was fixed onto the sidewall of the chamber near the exit. Experimental results show that the width and height of the chamber significantly affect critical wind speed and output power, respectively. The initial attack angle of the cantilever has important influence on the critical wind speed. Blunt body at the air entrance could remarkably decrease the critical wind speed. For a prototype with a 60 mm×20 mm×13 mm chamber, the length of the cantilever of 30 mm and the length of the piezoelectric sheet of 8 mm, the measured maximum output power is 1.1 mW under 17 m/s wind.
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Ismail, Ismail, Johanis John, Erlanda Augupta Pane, Rahman Maulana, Reza Abdu Rahman, and Agri Suwandi. "Experimental Evaluation for The Feasibility of Test Chamber in The Open-Loop Wind Tunnel." WSEAS TRANSACTIONS ON FLUID MECHANICS 16 (May 31, 2021): 120–26. http://dx.doi.org/10.37394/232013.2021.16.12.
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The test chamber in an open-loop wind tunnel is a critical part for aerodynamic experiment. The study aims to assess the feasibility of the new design of test chamber for open–loop wind tunnel by studying the fluid characteristic and the average pressure in the test chamber. The study is done by a series experimental test for the test chamber. From experimental test, the downstream velocity in the test chamber is increased from 8.9 m/s to 12.72 m/s where the pressure gradient is ranging from 6.19 to 8.398 atm with the overall turbulence intensity for the test chamber is 0.749%. According to the results, the designed open-loop wind tunnel is acceptable to use for an aerodynamic test.
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Ahmed, Razeen F., Yenas Yendrew, and Noor A. Ahmed. "Building a Practical Anechoic Chamber for Aero-Acoustic Measurements." Applied Mechanics and Materials 607 (July 2014): 685–93. http://dx.doi.org/10.4028/www.scientific.net/amm.607.685.
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The design, manufacture and installation of a practical and cost-effective anechoic chamber for aero-acoustic measurements are presented in this paper. The work was undertaken with a view to measure the aerodynamically generated noise of wind turbines under laboratory conditions. The chamber was designed to be used in conjunction with a wind tunnel. Tests were carried out to compare the reduction of noise levels from external sources with and without the chamber. The results obtained suggest a clear reduction of noise levels with different wind speeds, and as expected, resulted with higher reductions at higher wind tunnel speeds.
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Zhang, Shikai, Anlan Ding, Xiuguo Zou, Bo Feng, Xinfa Qiu, Siyu Wang, Shixiu Zhang, Yan Qian, Heyang Yao, and Yuning Wei. "Simulation Analysis of a Ventilation System in a Smart Broiler Chamber Based on Computational Fluid Dynamics." Atmosphere 10, no. 6 (June 6, 2019): 315. http://dx.doi.org/10.3390/atmos10060315.
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In this paper, a CFD (computational fluid dynamics) numerical calculation was employed to examine whether the ventilation system of the self-designed smart broiler house meets the requirements of cooling and ventilation for the welfare in poultry breeding. The broiler chamber is powered by two negative pressure fans. The fans are designed with different frequencies for the ventilation system according to the specific air temperature in the broiler chamber. The simulation of ventilation in the empty chamber involved five working conditions in this research. The simulation of ventilation in the broiler chamber and the simulation of the age of air were carried out under three working conditions. According to the measured dimensions of the broiler chamber, a three-dimensional model of the broiler chamber was constructed, and then the model was simplified and meshed in ICEM CFD (integrated computer engineering and manufacturing code for computational fluid dynamics). Two models, i.e., the empty chamber mesh model and the chamber mesh model with block model, were imported in the Fluent software for calculation. In the experiment, 15 measurement points were selected to obtain the simulated and measured values of wind velocity. For the acquired data on wind velocity, the root mean square error (RMSE) was 19.1% and the maximum absolute error was 0.27 m/s, which verified the accuracy of the CFD model in simulating the ventilation system of the broiler chamber. The boundary conditions were further applied to the broiler chamber model to simulate the wind velocity and the age of air. The simulation results show that, when the temperature was between 32 and 34 °C, the average wind velocity on the plane of the corresponding broiler chamber (Y = 0.2 m) was higher than 0.8 m/s, which meets the requirement of comfortable breeding. At the lowest frequency of the fan, the oldest age of air was less than 150 s, which meets the basic requirement for broiler chamber design. An optimization idea is proposed for the age of air analysis under three working conditions to improve the structure of this smart broiler chamber.
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Lira-Loarca, Andrea, Asunción Baquerizo, and Sandro Longo. "Interaction of Swell and Sea Waves with Partially Reflective Structures for Possible Engineering Applications." Journal of Marine Science and Engineering 7, no. 2 (February 2, 2019): 31. http://dx.doi.org/10.3390/jmse7020031.
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In this work, we investigate the interaction between the combination of wind-driven and regular waves and a chamber defined by a rigid wall and a thin vertical semi-submerged barrier. A series of laboratory experiments were performed with different values of incident wave height, wave period, and wind speed. The analysis focuses on the effect of the geometry of the system characterized in terms of its relative submergence d/h and relative width B/L. Results show that for the case of d/h = 0.58 a resonant effect takes place inside the chamber regardless of the wind speed. Wind-driven waves have a higher influence on the variation of the wave period of the waves seaward and leeward of the plate, as well as on the phase lag. Results show that the amplification or reduction of the wave energy inside the chamber is closely related to the wave period as compared to the 1st order natural period of the chamber.
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Kim, Min-Suk, and Jeong-Gyu Kim. "Effects of Thickness of Solid Media, Ventilation Rate, and Chamber Volume on Ammonia Emission from Liquid Fertilizers Using Dynamic Chamber-Capture System (DCS)." Agriculture 10, no. 6 (June 12, 2020): 226. http://dx.doi.org/10.3390/agriculture10060226.
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This study was conducted with the aim of improving the dynamic camber-capture system, which estimates ammonia emissions during the application of liquid fertilizer from livestock manure. We focused on the volume of the chamber and headspace, the height of the solid media, the flow rate of the pump, and the ventilation rate. Total ammoniacal nitrogen (NH3 + NH4+) is an important factor affecting ammonia volatilization. Even though the characteristics of liquid fertilizer were changed, the effect of total ammoniacal nitrogen on ammonia volatilization remained the largest. Increasing the thickness of solid media inside the chamber has the effect of reducing ammonia emission by reducing the contact area between liquid fertilizer and air. Although it is very difficult to measure and control the wind velocity in a chamber using a general vacuum pump, it can be indirectly evaluated through the ventilation rate in the macroscopic aspect. The higher the ventilation rate, the faster the flow of air in the chamber, which is linear with the increase in ammonia emission flux. We find that it may be necessary to improve the steady wind velocity within the chamber and of the linkages to upscale the wind tunnel system.
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Bielek, Boris, and Daniel Szabó. "New Façade Ventilation Units of under Pressure Controlled Ventilation System." Advanced Materials Research 1057 (October 2014): 113–20. http://dx.doi.org/10.4028/www.scientific.net/amr.1057.113.
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Task of controlled ventilation in modern residential buildings is to ensure optimum quality of interior environment and fulfill hygienic and thermal technical requirements guaranteeing comfort of user. The paper discusses development and experimental verification of atypical vertical ventilation units of under pressure controlled ventilation system for residential high-rise building. Recommended concept of solution to façade detail in relation to ventilation system. Optimized alternative of air inlet openings in the bottom level of vertical pilaster with function of air distribution channel for under pressure controlled ventilation system. The paper discusses laboratory experimental verification of physical properties of optimized alternative of ventilation units of under pressure controlled ventilation system for high-rise residential building in their development cycle. Boundary conditions of physical designing of envelope structures for load of wind-driven rain and their modifications for high-rise building in the locality of Bratislava. Hydrodynamic regime of air inlet openings of controlled ventilation system – maintaining water impermeability of air inlet openings of the ventilation system under the effect of wind-driven rain – laboratory experimental research in large rain chamber, its results and necessary construction modifications of elements of ventilation units. Aerodynamic regime of natural controlled ventilation system – quantification of volume of air flow rate through ventilation units in dependence to air pressure difference - laboratory experimental research in large pressure chamber. Acoustic properties of natural controlled ventilation system – quantification of index of air impermeability of controlled ventilation system in open and closed position - laboratory experimental research in acoustic chambers. Comparison by the experiment of verified parameters of ventilation units of under pressure controlled ventilation with design parameters.
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Afanasev, L. V., A. A. Yatskih, A. D. Kosinov, Yu G. Yermolaev, N. V. Semionov, O. P. Minin, and S. G. Shevelkov. "A Study of the Pulsations of Flow in the Settling Chamber and Their Relationship with the Pulsations of the Supersonic Flow." Siberian Journal of Physics 14, no. 2 (2019): 77–85. http://dx.doi.org/10.25205/2541-9447-2019-14-2-77-85.
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Experimental study of the influence of flow pulsation in settling chamber on the supersonic free stream disturbances was carried out. Data on the pulsations in the settling chamber and the efficiency of deturbulization system as well as the correlation of pulsations of the flow of settling chamber and flow pulsations in test section of T-325 supersonic wind tunnel of ITAM SB RAS were obtained.
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Martin-Gomez, Juan, M. Angeles Varo, Julieta Merida, and Maria P. Serratosa. "Bioactive Compounds of Chamber-Dried Blueberries at Controlled Temperature and Wines Obtained from Them." Journal of Chemistry 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/1567106.
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The effects of chamber drying under controlled temperature and moisture conditions and fermentation process on blueberry juices to obtain three wines were studied in this work. Drying was carried out with a view to increase the sugar content and obtain wines with an ethanol content similar to a commercial grape wine or to obtain sweet wines. Analyses included color parameters; browning index; and anthocyanin, flavonols, flavan-3-ol derivatives, and tannin concentrations, as well as vitamin C concentration and antioxidant activity. Based on the results, drying increases color and the concentration of anthocyanins and tannins most probably by the effect of dehydration of the berries and diffusion of the colored compounds from the skin to the pulp due to the structural alterations in their skin. In addition, drying decreases flavonols, flavan-3-ol derivatives, and vitamin C concentrations. The browning index, anthocyanins, and tannins decreased with the fermentation time, and vitamin C was constant with the fermentation time. The sensory analysis showed that the wines with the best sensory characteristics were those with residual sugar, partial fermented wines 1 and 2.
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McGinn, S. M., and H. H. Janzen. "Ammonia sources in agriculture and their measurement." Canadian Journal of Soil Science 78, no. 1 (February 1, 1998): 139–48. http://dx.doi.org/10.4141/s96-059.
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There are several reasons why the measurement of ammonia emissions is important in agriculture. The emission of ammonia from stored and land-applied manure to the atmosphere can result in a significant loss of nitrogen for crop production. It is necessary to quantify this loss to evaluate manure handling practices for maintaining the nutritive value of the manure. Minimizing the emissions of ammonia from manure also reduces agriculture's impact on the environment. A high atmospheric concentration of ammonia can result in acidification of land and water surfaces, cause plant damage and reduce plant biodiversity in natural systems. Ammonia emissions from manure coincide with odors, which are a nuisance in areas of intensive livestock operations. Reducing ammonia emissions by altering manure management will also reduce odor problems. The purpose of this paper is to review agricultural sources of ammonia and describe techniques used in determining the loss of ammonia from manure-amended soils. Micrometeorological techniques are used to estimate field scale emissions whereas, for small plots where treatment (effects) is used, chambers and mass balance techniques are more suitable methods. A simple method is described, which, when combined with a denuder sampler mounted on a wind vane, permits flexibility in experimental design and requires fewer ammonia samples than the traditional mass balance approach. A chamber method making use of diffusion samplers that can measure the ammonia concentration in the air at the soil surface is also described. Key words: Ammonia, nitrogen loss, agriculture, manure, micrometeorology, chamber
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Monje, Oscar, and Bruce Bugbee. "Radiometric Method for Determining Canopy Stomatal Conductance in Controlled Environments." Agronomy 9, no. 3 (February 27, 2019): 114. http://dx.doi.org/10.3390/agronomy9030114.
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Canopy stomatal conductance is a key physiological factor controlling transpiration from plant canopies, but it is extremely difficult to determine in field environments. The objective of this study was to develop a radiometric method for calculating canopy stomatal conductance for two plant species—wheat and soybean from direct measurements of bulk surface conductance to water vapor and the canopy aerodynamic conductance in controlled-environment chambers. The chamber provides constant net radiation, temperature, humidity, and ventilation rate to the plant canopy. In this method, stepwise changes in chamber CO2 alter canopy temperature, latent heat, and sensible heat fluxes simultaneously. Sensible heat and the radiometric canopy-to-air temperature difference are computed from direct measurements of net radiation, canopy transpiration, photosynthesis, radiometric temperature, and air temperature. The canopy aerodynamic conductance to the transfer of water vapor is then determined from a plot of sensible heat versus radiometric canopy-to-air temperature difference. Finally, canopy stomatal conductance is calculated from canopy surface and aerodynamic conductances. The canopy aerodynamic conductance was 5.5 mol m−2 s−1 in wheat and 2.5 mol m−2 s−1 in soybean canopies. At 400 umol mol−1 of CO2 and 86 kPa atmospheric pressure, canopy stomatal conductances were 2.1 mol m−2 s−1 for wheat and 1.1 mol m−2 s−1 for soybean, comparable to canopy stomatal conductances reported in field studies. This method measures canopy aerodynamic conductance in controlled-environment chambers where the log-wind profile approximation does not apply and provides an improved technique for measuring canopy-level responses of canopy stomatal conductance and the decoupling coefficient. The method was used to determine the response of canopy stomatal conductance to increased CO2 concentration and to determine the sensitivity of canopy transpiration to changes in canopy stomatal conductance. These responses are useful for improving the prediction of ecosystem-level water fluxes in response to climatic variables.
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Jiang, Kaiyun, and Ralph Kaye. "Comparison study on portable wind tunnel system and isolation chamber for determination of VOCs from areal sources." Water Science and Technology 34, no. 3-4 (August 1, 1996): 583–89. http://dx.doi.org/10.2166/wst.1996.0479.
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Many environmental monitoring programmes require the determination of volatile organic compounds (VOCs) emitted from large areal sources including liquid surfaces. A study was carried out to compare existing sampling techniques. Both the isolation chamber method (static technique) and the wind tunnel method (dynamic technique) were examined. A review of the mechanisms suggested that static techniques would not be appropriate for determining emissions from liquid surfaces which result from gas phase controlled volatilisation processes. A portable wind tunnel developed at the University of New South Wales and an isolation chamber built to USEPA specification were used in an experimental study of emissions from aqueous liquid surfaces. An acetone solution was chosen to represent gas phase controlled volatilisation processes. Toluene and methyl ethyl ketone in aqueous solution were chosen, respectively to investigate (1) liquid phase controlled volatilisation processes, and (2) combined gas and liquid phase controlled volatilisation processes. It was found that the use of the isolation chamber method resulted in different degrees of underestimation of the emission rates for the above three compounds. The wind tunnel method is suitable for sampling all VOC emissions from areal sources.
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Mehta, R. D., and P. Bradshaw. "Longitudinal vortices imbedded in turbulent boundary layers Part 2. Vortex pair with ‘common flow’ upwards." Journal of Fluid Mechanics 188 (March 1988): 529–46. http://dx.doi.org/10.1017/s0022112088000837.
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Detailed mean flow and turbulence measurements have been made in a low-speed turbulent boundary layer in zero pressure gradient with an isolated, artificially generated vortex pair imbedded in it. The vortices, generated by two half-delta wings on the floor of the wind-tunnel settling chamber, rotate in opposite directions such that the ‘common flow’ between the vortices is away from the surface, and the vortex pair draws boundary-layer fluid upwards. The distance of the vortex cores above the surface grows downstream, and is roughly twice the local boundary-layer thickness. The cancellation of circulation by mixing of fluid from the two vortices is slow, and the vortices are identifiable down the full length of the test section. As in the case of the single vortex investigated in Part 1 of this series, large changes in structural parameters of the turbulence occur.
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Whitlow, T. H., and L. Y. Mudrak. "Effect of Pot Lip Shape on Soil Surface Evaporative Losses." Journal of Environmental Horticulture 5, no. 2 (June 1, 1987): 41–45. http://dx.doi.org/10.24266/0738-2898-5.2.41.
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Small pots containing a loam soil were monitored in a growth chamber and wind tunnel to determine the effect of 13 different lip shapes on evaporation from the soil surface. In the growth chamber, pots with modified lips showed evaporative losses ranging from 52-95% of the unmodified control during the first 24 hrs following watering. The same trend was observed during the second 24 hrs following watering but not during the third 24 hr period. In the wind tunnel, nine treatments showed significant reductions in evaporation in comparison to the control 24 hrs after watering; no differences were observed after three days of drying.
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Barták, Miloš, Kamil Láska, Josef Hájek, and Peter Váczi. "Microclimate variability of Antarctic terrestrial ecosystems manipulated by open top chambers: Comparison of selected austral summer seasons within a decade." Czech Polar Reports 9, no. 1 (January 1, 2019): 88–106. http://dx.doi.org/10.5817/cpr2019-1-8.
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Open top chambers (OTCs) were established in the northern part of the James Ross Island, Antarctic Peninsula, as a part of long-term program in January 2007. They were installed in two typical locations differing in vegetation cover. First group was set in a seashore ecosystem dominated by moss carpet supplemented with few lichen species. The other group was located on the top of a volcanic mesa (350 m a.s.l.) with irregular cover of lichens Usnea antarctica and Umbilicaria decussata. Temperature regimes inside and outside OTCs were continuously measured and related to year-round reference meteorological data. For majority of OTC installations, temperature increase caused by OTC was apparent in the period of September-March. Detailed analysis of chamber effect on the increase in air, surface, vegetation, and ground temperatures was done for late austral summer seasons of 2007 and 2008, and 10 years later, the seasons of 2017 and 2018. The OTC-induced temperature increase was more pronounced for mesa than seashore plot. For both locations, OTC-induced increase in temperature was highest for warm days with full sunshine and limited wind speed. On stormy days with overcast sky and high wind speed, the shift in temperature was smaller. Consequences of a long-term manipulation of Antarctic terrestrial ecosystems by OTCs for moss and lichen ecophysiology are discussed.
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Pomelov, Vladislav, Olga Poddaeva, and Pavel Churin. "Experimental studies of wind impact on coke chambers." MATEC Web of Conferences 251 (2018): 02034. http://dx.doi.org/10.1051/matecconf/201825102034.
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The article deals with the experimental investigation of the wind effect on coke chambers, which are part of delayed coking units. These structures are one of the most susceptible structures of an increased level of responsibility in the structure of industrial enterprises, which is primarily due to their height (height exceeds 100 meters). Experimental researches were carried out on the basis of the Educational Scientific and Production Laboratory for Aerodynamic Tests of Building Structures of NIU MGSU, using the Unique Scientific Installation of the Large Gradient Wind Tunnel. The text of the article shows the main features of the models made for carrying out experimental studies, briefly describes the process of testing and their results.
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Tague, Noel Thistle. "Resonance Chambers and Industrial Nightmares: Big Wind’s Civic Afflictions." Rhetoric Review 38, no. 1 (January 2, 2019): 50–62. http://dx.doi.org/10.1080/07350198.2019.1549412.
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Platonov, Aleksey, Yu Mikhaylova, Svetlana Snegireva, Aleksandra Kiseleva, and Nikolay Mozgovoy. "DETERMINING THE MINIMUM HEIGHT OF THE EMISSION SOURCE FROM CAMERA FOR DRYING BEECH WOOD." Forestry Engineering Journal 9, no. 4 (January 13, 2020): 117–25. http://dx.doi.org/10.34220/issn.2222-7962/2019.4/13.
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The process of chamber drying of wood is accompanied by a prolonged exposure to wood of heat and moisture. As a result of this effect, the ligno-carbohydrate complex of wood decomposes with the release of various harmful substances, the most dangerous are furfural and formaldehyde. The amount of furfural and formaldehyde in the spent drying agent depends on the initial moisture content of the wood, duration and drying mode. The degree of environmental impact of harmful substances depends on the drying regime, the height of the release of the drying agent from the chamber, and environmental conditions. The low emission height of the spent drying agent with harmful substances leads to exceeding the maximum permissible concentration of harmful substances in the surface layer. Therefore, the aim of research is to reduce the concentration of furfural and formaldehyde in the surface layer. The studies were carried out on beech wood growing in the Krasnodar region. It was found that the maximum amount of furfural and formaldehyde is released from beech wood during drying by mild conditions. The largest amount of harmful substances is released from beech wood in the first stage, when free moisture is removed, regardless of the drying mode. It is possible to lower the value of near-ground concentration at the border of the sanitary zone by correctly choosing the height of the source of dispersion of harmful substances. The work determines the height of the source of emissions of harmful substances from the drying chamber, depending on the drying regime of beech wood and climatic environmental conditions. In the warm season and at dangerous wind speeds (less than 1 m / s), the height of the source of emission during drying of beech wood should be the greatest, in the cold - the smallest. Based on the studies performed, recommendations are given for the placement of exhaust pipes and their heights for drying chambers, taking into account the volume of simultaneously dried wood.
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Wolf, B. O., K. M. Wooden, and G. E. Walsberg. "Effects of complex radiative and convective environments on the thermal biology of the white-crowned sparrow (Zonotrichia leucophrys gambelii)." Journal of Experimental Biology 203, no. 4 (February 15, 2000): 803–11. http://dx.doi.org/10.1242/jeb.203.4.803.
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The energy budgets of small endotherms are profoundly affected by characteristics of the physical environment such as wind speed, air temperature and solar radiation. Among these, solar radiation represents a potentially very large heat load to small animals and may have an important influence on their thermoregulatory metabolism and heat balance. In this investigation, we examined the interactive effects of wind speed and irradiance on body temperature, thermoregulatory metabolism and heat balance in the white-crowned sparrow (Zonotrichia leucophrys gambelii). We measured changes in metabolic heat production by exposing birds to different wind speeds (0.25, 0.5, 1.0 and 2.0 m s(−1)) and irradiance combinations (<3 W m(−2) and 936+/−11 W m(−2); mean +/− s.d.) at an air temperature of 10 degrees C. Body temperature was not affected by wind speed, but was significantly higher in animals not exposed to simulated solar radiation compared with those exposed at most wind speeds. In the absence of solar radiation, metabolic heat production was strongly affected by wind speed and increased by 30 % from 122 to 159 W m(−2) as wind speed increased from 0.25 to 2.0 m s(−1). Metabolic heat production was even more strongly influenced by wind speed in the presence of simulated solar radiation and increased by 51% from 94 to 142 W m(−2) as wind speed increased from 0.25 to 2. 0 m s(−1). Solar heat gain was negatively correlated with wind speed and declined from 28 to 12 W m(−2) as wind speed increased from 0.25 to 2.0 m s(−1) and, at its maximum, equaled 11% of the radiation intercepted by the animal. The overall thermal impact of the various wind speed and irradiance combinations on the animal's heat balance was examined for each treatment. Under cold conditions, with no solar radiation present, an increase in wind speed from 0.25 to 2.0 m s(−1) was equivalent to a decrease in chamber air temperature of 12.7 degrees C. With simulated solar radiation present, a similar increase in wind speed was equivalent to a decrease in chamber air temperature of 16 degrees C. Overall, shifting environmental conditions from a wind speed of 0.25 m s(−1) and irradiance of 936 W m(−2) to a wind speed of 2.0 m s(−1) with no short-wave radiation present was equivalent to decreasing chamber air temperature by approximately 20 degrees C. The sensitivity to changes in the convective environment, combined with the complex effects of changes in irradiance levels revealed by re-analyzing data published previously, significantly complicates the task of estimating the heat balance of animals in nature.
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Lee, In. "Plenum chamber effect on wind-tunnel resonance by the finite-elementmethod." AIAA Journal 26, no. 9 (September 1988): 1087–93. http://dx.doi.org/10.2514/3.10015.
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de Souza Obata, Daniel Henrique, Thiago Antonini Alves, Márcio Antonio Bazani, and Amarildo Tabone Paschoalini. "Experimental Analysis of a Vapor Chamber Applied to Thermal Management of Microelectronics." Advanced Materials Research 1120-1121 (July 2015): 1368–72. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.1368.
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In this research, a vapor chamber embedded in the base of a heat sink was experimentally analyzed for the application in thermal management of microelectronics. The vapor chamber was produced by a copper and molybdenum alloy with length of 240 mm, width of 54 mm, thickness of 3 mm, and capillary structures composed by copper screen meshes. The working fluid used was de-ionized water. The pure aluminum heat sink was cooled by air forced convection and the evaporator vapor chamber was heated using an electrical resistor simulating integrated circuit power dissipation. The experimental tests were done in a suction type wind tunnel with open return for a heat load varying from 20 to 80 W and for an airflow velocity varying from 1 to 4 m/s. The experimental results showed that the considered vapor chamber worked successfully, maintaining low operating temperature.
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Eremenko, Z. Ye, Ye M. Ganapolsky, V. N. Skresanov, V. V. Vasylchenko, V. G. Gerzhikova, T. A. Zhylyakova, and N. C. Anikina. "CYLINDRICAL RESONATOR WITH RADIAL CHAMBER FOR COMPLEX PERMITTIVITY DETERMINATION OF TABLE WINES." Telecommunications and Radio Engineering 69, no. 17 (2010): 1573–90. http://dx.doi.org/10.1615/telecomradeng.v69.i17.60.
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McGoey, Brechann V., Rafal Janik, and John R. Stinchcombe. "Individual chambers for controlling crosses in wind‐pollinated plants." Methods in Ecology and Evolution 8, no. 7 (January 30, 2017): 887–91. http://dx.doi.org/10.1111/2041-210x.12722.
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Brasil, Reyolando Manoel Lopes Rabelo da Fonseca, L. C. S. Feitosa, and José Manoel Balthazar. "A Nonlinear and Non-Ideal Wind Generator Supporting Structure." Applied Mechanics and Materials 5-6 (October 2006): 433–42. http://dx.doi.org/10.4028/www.scientific.net/amm.5-6.433.
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We present a simple mathematical model of a wind turbine supporting tower. Here, the wind excitation is considered to be a non-ideal power source. In such a consideration, there is interaction between the energy supply and the motion of the supporting structure. If power is not enough, the rotation of the generator may get stuck at a resonance frequency of the structure. This is a manifestation of the so-called Sommerfeld Effect. In this model, at first, only two degrees of freedom are considered, the horizontal motion of the upper tip of the tower, in the transverse direction to the wind, and the generator rotation. Next, we add another degree of freedom, the motion of a free rolling mass inside a chamber. Its impact with the walls of the chamber provides control of both the amplitude of the tower vibration and the width of the band of frequencies in which the Sommerfeld effect occur. Some numerical simulations are performed using the equations of motion of the models obtained via a Lagrangian approach.
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Kim, Min-Suk, Namin Koo, Seunghun Hyun, and Jeong-Gyu Kim. "Comparison of Ammonia Emission Estimation between Passive Sampler and Chamber System in Paddy Soil after Fertilizer Application." International Journal of Environmental Research and Public Health 17, no. 17 (September 2, 2020): 6387. http://dx.doi.org/10.3390/ijerph17176387.
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Ammonia (NH3) is an important precursor for particulate secondary aerosol formation. This study was conducted to evaluate the applicability of a passive sampler (PAS) for estimating the NH3 emission from chemical fertilizer application (85 kg-N·ha−1) at field scale and to compare the results with a chamber system for the calculation of NH3 emission flux at lab scale. The application of chemical fertilizer increased the ambient NH3 concentration from 7.11 to 16.87 μg·m−3. Also, the ambient NH3 concentration measured by the PAS was found to be highly influenced by not only the chemical fertilizer application but also the weather (temperature and rainfall). Wind rose diagram data can be useful for understanding the distribution of ambient NH3 concentration. In the case of a chamber with few environmental variables, NH3 was emitted very quickly in the early stages and gradually decreased, whereas it was delayed at intervals of about one week at the site. It was found that daily temperature range, atmospheric disturbance by wind and rainfall, changes in soil moisture, and the presence of a flooded water table were the main influencing factors. The PAS data and the chamber system data were observed to have significant differences in spatial-temporal scale. In order to reduce the gap, it seems to be necessary to further develop a chamber system, in order to improve the precision of field analysis and to strengthen the connection between experimental results.
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Seymour, Jasmine. "From Armenia to Poland ‘with love’s light wings’." Cahiers Élisabéthains: A Journal of English Renaissance Studies 104, no. 1 (March 7, 2021): 95–104. http://dx.doi.org/10.1177/0184767821991553.
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On 30 July 2019, Yerevan State Chamber Theatre’s unconventional version of Romeo and Juliet was performed at the annual Gdańsk Shakespeare Theatre Festival in Poland, after successfully premiering in Yerevan, Armenia, in 2017. Following the overwhelming success of the production with local and international audiences and critics, invitations from other European festivals followed. When the current devastating restrictions imposed on theatres worldwide by the Covid-19 pandemic are finally lifted, the journey of the world’s best-known love story retold by this innovative theatre troupe will resume.
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Jansen, Joachim, Brett F. Thornton, Alicia Cortés, Jo Snöälv, Martin Wik, Sally MacIntyre, and Patrick M. Crill. "Drivers of diffusive CH<sub>4</sub> emissions from shallow subarctic lakes on daily to multi-year timescales." Biogeosciences 17, no. 7 (April 8, 2020): 1911–32. http://dx.doi.org/10.5194/bg-17-1911-2020.
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Abstract. Lakes and reservoirs contribute to regional carbon budgets via significant emissions of climate forcing trace gases. Here, for improved modelling, we use 8 years of floating chamber measurements from three small, shallow subarctic lakes (2010–2017, n=1306) to separate the contribution of physical and biogeochemical processes to the turbulence-driven, diffusion-limited flux of methane (CH4) on daily to multi-year timescales. Correlative data include surface water concentration measurements (2009–2017, n=606), total water column storage (2010–2017, n=237), and in situ meteorological observations. We used the last to compute near-surface turbulence based on similarity scaling and then applied the surface renewal model to compute gas transfer velocities. Chamber fluxes averaged 6.9±0.3 mg CH4 m−2 d−1 and gas transfer velocities (k600) averaged 4.0±0.1 cm h−1. Chamber-derived gas transfer velocities tracked the power-law wind speed relation of the model. Coefficients for the model and dissipation rates depended on shear production of turbulence, atmospheric stability, and exposure to wind. Fluxes increased with wind speed until daily average values exceeded 6.5 m s−1, at which point emissions were suppressed due to rapid water column degassing reducing the water–air concentration gradient. Arrhenius-type temperature functions of the CH4 flux (Ea′=0.90±0.14 eV) were robust (R2≥0.93, p<0.01) and also applied to the surface CH4 concentration (Ea′=0.88±0.09 eV). These results imply that emissions were strongly coupled to production and supply to the water column. Spectral analysis indicated that on timescales shorter than a month, emissions were driven by wind shear whereas on longer timescales variations in water temperature governed the flux. Long-term monitoring efforts are essential to identify distinct functional relations that govern flux variability on timescales of weather and climate change.
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Cabrera, M. L., D. E. Kissel, R. C. Davis, N. P. Qafoku, and W. I. Segars. "Design and Ammonia-Recovery Evaluation of a Wind Speed-Sensitive Chamber System." Soil Science Society of America Journal 65, no. 4 (July 2001): 1302–6. http://dx.doi.org/10.2136/sssaj2001.6541302x.
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Woolley, Christopher. "Dispersal behavior in agrobiont spiders (Linyphiidae) — differential response to a wind chamber." Journal of Arachnology 44, no. 3 (November 2016): 405–7. http://dx.doi.org/10.1636/j15-67.1.
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