Air scrubbing techniques for the reduction of gaseous emissions from livestock farms. Actual knowledge in the Netherlands and possibilities for implementation on Spanish farms.

In The Netherlands, packed-bed biotrickling filters and acid scrubbers for removal of ammonia from exhaust air of animal houses are off-the-shelf techniques for ammonia removal. At the moment a new generation of so-called "multi-pollutant scrubbers" is being developed and tested that also removes odour and particulate matter from the air. Air cleaning systems are unusual in Spanish farms. The study of these techniques and their adaptation to Spanish farms, can be an interesting issue in order to achieve the national gas emission reduction commitments, and also to reduce social nuisances

Evaluating three-pillar sustainability modelling approaches for dairy cattle production systems

Milk production in Europe is facing major challenges to ensure its economic, environmental, and social sustainability. It is essential that holistic concepts are developed to ensure the future sustainability of the sector and to assist farmers and stakeholders in making knowledge-based decisions. In this study, integrated sustainability assessment by means of whole-farm modelling is presented as a valuable approach for identifying factors and mechanisms that could be used to improve the three pillars (3Ps) of sustainability in the context of an increasing awareness of economic profitability, social well-being, and environmental impacts of dairy production systems (DPS). This work aims (i) to create an evaluation framework that enables quantitative analysis of the level of integration of 3P sustainability indicators in whole-farm models and (ii) to test this method. Therefore, an evaluation framework consisting of 35 indicators distributed across the 3Ps of sustainability was used to evaluate three whole-farm models. Overall, the models integrated at least 40% of the proposed indicators. Different results were obtained for each sustainability pillar by each evaluated model. Higher scores were obtained for the environmental pillar, followed by the economic and the social pillars. In conclusion, this evaluation framework was found to be an effective tool that allows potential users to choose among whole-farm models depending on their needs. Pathways for further model development that may be used to integrate the 3P sustainability assessment of DPS in a more complete and detailed way were identified. © 2021 by the authors.This study was financially supported by the German Federal Ministry of Food and Agriculture (BMEL) through the Federal Office for Agriculture and Food (BLE) under grant number 2819ERA08A (MilKey project, funded under the Joint Call 2018 ERA-GAS, SusAn and ICT-AGRI 2 on ?Novel technologies, solutions and systems to reduce the greenhouse gas emissions in animal production systems?). BC3-Research is supported by the Spanish Government through Mar?a de Maeztu excellence accreditation 2018-2022 (Ref. MDM-2017-0714) and by the Basque Government through the BERC 2018-2021 program. Agustin del Prado is financed through the Ramon y Cajal program by the Spanish Ministry of Economy, Industry, and Competitiveness (RYC-2017-22143)

A meta-analysis of environmental factor effects on ammonia emissions from dairy cattle houses

[EN] Livestock housing is one of the main sources of ammonia (NH3) emissions from agriculture. Different management and environmental factors are known to affect NH3 emissions from housing systems. The aim of this study was to quantitatively define the effect of temperature, wind speed, relative humidity, and ventilation rate on NH3 release rates from dairy cattle housing by conducting a meta-analysis of published scientific results. A literature survey was performed to review studies published before January 2018 that have identified statistical relationships between NH3 emissions and environmental factors such as air temperature, wind speed, relative humidity, or ventilation rate in dairy cattle housing. Experimental values were related using a mixed model analysis in order to analyse the effect of environmental factors on NH3 emissions. For this exercise, a total of 19 peerreviewed papers were considered and 27 different relations between air temperature and NH3 emissions were used for the analysis. A significant effect of air temperature inside the barn and ventilation rate on NH3 emissions was observed. Results showed that NH3 emissions increased linearly with increasing air temperature (ºC) inside the barn by 1.47 g [NH3] cow 1 d 1 when temperature increased by one degree. For ventilation rate, an increase of 100 m3 h 1 cow 1 led to an increase in NH3 emissions of 0.007 g [NH3] cow 1 d 1 . The equations obtained in this work might help to provide information on NH3 barnrelated emissions behaviour under these environmental conditions, bearing in mind that other source of emissions such as diet composition and animal performance might be also affected by climate changes.This study is part of the project OPTIBARN and was financially supported by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria through the research grant 618105 FACCE Era Net Plus - Food Security, Agriculture, Climate Change ERA-NET plus. This work has been also funded by the Basque Government through the BERG 2018-2021 program and by Spanish Ministry of Economy and Competitiveness MINECO through BC3 Maria de Maeztu excellence accreditation MDM-2017-0714.Sanchis Jiménez, EM.; Calvet, S.; Del Prado, A.; Estellés, F. (2019). A meta-analysis of environmental factor effects on ammonia emissions from dairy cattle houses. Biosystems Engineering. 178:176-183. https://doi.org/10.1016/j.biosystemseng.2018.11.017S17618317

Heat stress effects in milk yield and milk traits at farm scale

This study was funded by ERA44-OPTIBARN-BC3 project.Galán, E.; Sanchís Jiménez, EM.; Estellés, F.; Calvet, S.; Del Prado, A. (2016). Heat stress effects in milk yield and milk traits at farm scale. Advances in Animal Biosciences. 7(3):238-239. https://doi.org/10.1017/S2040470016000261S2382397

Positioning of the cross-stitch on the modified Kessler core tendon suture

[EN] Cryopreserved human tendons were sutured with different variations of a modified Kessler-type grasping suture in a series of different designs in order to assess the influence of the distance between the cross-stitch on the core suture (5 and 10 mm from the cut tendon edge) on the peripheral suture. An original mathematical model was employed to explain the mechanical behavior (strength, deformation, and distribution of load) of the different suture designs. The effect of the peripheral epitendinous suture, combined with the distance of the core suture, was evaluated. The variation of core suture distance had no relevant consequences on the overall resilience of the design. However, increasing the distance between the cross-stitches of the core suture reduces the deformation that is absorbed not only by the core suture itself but also by the peripheral suture. Adding a peripheral epitendinous suture to a 10-mm design almost doubles the breaking load in absolute values. The mathematical model predicts that the peripheral suture will support a greater load when the distance of the core suture cross-stitches is increased. The evidence level is II.Gil Santos, L.; Monleón Pradas, M.; Gomar-Sancho, F.; Más Estellés, J. (2018). Positioning of the cross-stitch on the modified Kessler core tendon suture. Journal of the Mechanical Behavior of Biomedical Materials. 80:27-32. https://doi.org/10.1016/j.jmbbm.2018.01.018S27328

Uncertainty in the measurement of indoor temperature and humidity in naturally ventilated dairy buildings as influenced by measurement technique and data variability

[EN] The microclimatic conditions in dairy buildings affect animal welfare and gaseous emissions. Measurements are highly variable due to the inhomogeneous distribution of heat and humidity sources (related to farm management) and the turbulent inflow (associated with meteorologic boundary conditions). The selection of the measurement strategy (number and position of the sensors) and the analysis methodology adds to the uncertainty of the applied measurement technique. To assess the suitability of different sensor positions, in situations where monitoring in the direct vicinity of the animals is not possible, we collected long-term data in two naturally ventilated dairy barns in Germany between March 2015 and April 2016 (horizontal and vertical profiles with 10 to 5 min temporal resolution). Uncertainties related to the measurement setup were assessed by comparing the device outputs under lab conditions after the on-farm experiments. We found out that the uncertainty in measurements of relative humidity is of particular importance when assessing heat stress risk and resulting economic losses in terms of temperature-humidity index. Measurements at a height of approximately 3 m-3.5 m turned out to be a good approximation for the microclimatic conditions in the animal occupied zone (including the air volume close to the emission active zone). However, further investigation along this cross-section is required to reduce uncertainties related to the inhomogeneous distribution of humidity. In addition, a regular sound cleaning (and if possible recalibration after few months) of the measurement devices is crucial to reduce the instrumentation uncertainty in long-term monitoring of relative humidity in dairy barns (C) 2017 The Authors. Published by Elsevier Ltd on behalf of IAgrE.The work was financially supported by the German Federal Ministry of Food and Agriculture (BMEL) through the Federal Office for Agriculture and Food (BLE), grant number 2814ERA02C.Hempel, S.; König, M.; Menz, C.; Janke, D.; Amon, B.; Banhazi, T.; Estellés, F.... (2018). Uncertainty in the measurement of indoor temperature and humidity in naturally ventilated dairy buildings as influenced by measurement technique and data variability. Biosystems Engineering. 166:58-75. https://doi.org/10.1016/j.biosystemseng.2017.11.004S587516

Adapting concurrency throttling and voltage–frequency scaling for dense eigensolvers

We analyze power dissipation and energy consumption during the execution of high-performance dense linear algebra kernels on multi-core processors. On top of this analysis, we propose and evaluate several strategies to adapt concurrency throttling and the voltage–frequency setting in order to obtain an energy-efficient execution of LAPACK’s routine dsytrd. Our strategies take into account the differences between the memory-bound and CPU-bound kernels that govern this routine, and whether problem data fits into the processor’s last level cache.This work was supported by the CICYT Project TIN2011-23283 of MINECO and FEDER, the EU Project FP7 318793 “EXA2GREEN”, and the FPU program of the Ministerio de Educación, Cultura y Deporte

Unexpected vertical structure of the Saharan Air Layer and giant dust particles during AER-D

The Saharan Air Layer (SAL) in the summertime eastern Atlantic is typically well mixed and 3-4 km deep, overlying the marine boundary layer (MBL). In this paper, we show experimental evidence that at times a very different structure can be observed. During the AERosol properties - Dust (AER-D) airborne campaign in August 2015, the typical structure described above was observed most of the time, and was associated with a moderate dust content yielding an aerosol optical depth (AOD) of 0.3-0.4 at 355 nm. In an intense event, however, an unprecedented vertical structure was observed close to the eastern boundary of the basin, displaying an uneven vertical distribution and a very large AOD (1.5-2), with most of the dust in a much lower level than usual (0.3-2 km). Estimated dust concentrations and column loadings for all flights during the campaign spanned 300-5500 and 0.8-7.5 g m−2, respectively. The shortwave direct radiative impact of the intense dust event has been evaluated to be as large as −260±30 and −120±15 W m−2 at the surface and top of atmosphere (TOA), respectively. We also report the correlation of this event with anomalous lightning activity in the Canary Islands. In all cases, our measurements detected a broad distribution of aerosol sizes, ranging from ∼0.1 to ∼80 µm (diameter), thus highlighting the presence of giant particles. Giant dust particles were also found in the MBL. We note that most aerosol models may miss the giant particles due to the fact that they use size bins up to 10-25 µm. The unusual vertical structure and the giant particles may have implications for dust transport over the Atlantic during intense events and may affect the estimate of dust deposited to the ocean. We believe that future campaigns could focus more on events with high aerosol load and that instrumentation capable of detecting giant particles will be key to dust observations in this part of the world

Ammonia and greenhouse gas emissions from an enriched cage laying hen facility

[EN] Ammonia, methane, nitrous oxide and carbon dioxide emissions were measured during a complete production cycle in an enriched cage laying hen facility under Oceanic climate conditions. Continuous monitoring of gas concentration, ventilation rate and environmental parameters were conducted from April 2012 to September 2013. The seasonal and diurnal pattern of gas emissions was analysed. Seasonality effect was found for NH3 emission, showing an average emission of 144.9 mg d 1 hen 1 and 90.3 mg d 1 hen 1 in summer and winter, respectively. On the contrary, diurnal pattern of NH3 emission did not differ between these seasons. For CO2, mean emission values did not show seasonality, although the diurnal pattern differed between winter and summer. Results obtained for CH4 and N2O emissions did not provide sufficient evidence to determine either seasonality or diurnal effect on these gases. An NH3 emission factor of 7% of total N in manure was defined for this system. These losses increased at higher ventilation rates and lower belt cleaning frequencies. Thus, NH3 mitigation strategies at housing level should consider both parameters. Further studies would be necessary to determine how these factors regulate NH3 emission at laying hen houses. © 2016 IAgrE. Published by Elsevier Ltd. All rights reservedThis work has been funded by BATFARM Interreg-Atlantic Area Project (2009-1/071) entitled "Evaluation of best available techniques to decrease air and water pollution in animal farms". Oier Alberdi holds a grant from the Ph.D. student's research program of the Department of Economic Development and Competitiveness of the Basque Government. The authors are especially grateful to Larrabe Oilotegia S.A.T. that facilitated productive data and access to the farm and to the engineering company Ingenieria Avicola S.L. for the detailed information on ventilation aspects of the installation.Alberdi, O.; Arriaga, H.; Calvet, S.; Estellés, F.; Merino, P. (2016). Ammonia and greenhouse gas emissions from an enriched cage laying hen facility. Biosystems Engineering. 144:1-12. doi:10.1016/j.biosystemseng.2016.01.009S11214

Evaluation of the NH3 Removal Efficiency of an Acid Packed Bed Scrubber Using Two Methods: A Case Study in a Pig Facility

[EN] The use of air cleaning systems to reduce ammonia emissions from animal houses is increasing. These systems are normally used in order to comply with local or national regulations of ammonia emission. Therefore, accurate determination of the proportion of ammonia being removed by these systems is crucial. There are two main methods available to measure ammonia removal efficiency of scrubbers: air balance (based on the measurement of ammonia concentrations in air) and combined water-air balance (in which it is also necessary to determine the amount of nitrogen recovered in the liquid phase). The first method is simpler to establish, while the second method might provide deeper information about the processes occurring. The main aim of this work was to assess, in terms of the variability of the results, the use of these two methods to evaluate the efficiency of an acid packed bed scrubber on a pig farm. An acid packed bed scrubber (70% NH3 removal) was monitored during ten complete 24 h cycles for ammonia concentrations, airflow rates, and nitrogen accumulation in the acid solution basin. The average efficiency calculated using the air balance method was 71% (+/- 4%), close to the design value of 70%, while the average efficiency when using the combined water-air balance method was 255% (+/- 53%). The accumulation and precipitation of ammonium salts in the packing material seem to be the main cause of the high variability and inaccuracy of the combined water-air balance method observed for this type of scrubber. According to these results, it is recommended to use the air balance method when determining the ammonia removal efficiency for acid packed bed scrubbers similar to the one studied here. According to the variability of the results observed in this work, at least 24 measurement days are needed in order to keep the relative error below 5% when using the air balance method to determine the ammonia removal efficiency of an acid packed bed scrubberWe would like to thank the Netherlands Ministry of Economic Affairs, Agriculture, and Innovation and the Netherlands Ministry of Infrastructure and the Environment for financial support. We also acknowledge the owner of the facility where the study was conducted for allowing the access to the building and for help in many other ways.Estellés, F.; Melse, R.; Ogink, NWM.; Calvet Sanz, S. (2011). Evaluation of the NH3 Removal Efficiency of an Acid Packed Bed Scrubber Using Two Methods: A Case Study in a Pig Facility. Transactions of the ASABE. 54(5):1905-1912. https://doi.org/10.13031/2013.39831S1905191254