Now showing 1 - 10 of 65
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A dispersion modelling approach to determine the odour impact of intensive poultry production units in Ireland

2006-10, Hayes, Enda T., Curran, Thomas P., Dodd, V. A.

The use of atmospheric dispersion modelling has become more common for the determination of odour impacts from existing poultry production facilities and the assessment of setback distances for new facilities. Setback distances for broiler, layer and turkey units were determined using the atmospheric dispersion model ISCST3 and the Environmental Protection Agency (EPA, Ireland) recommended criterion (C98.1-h <= 6.0 ou(E) m(-3)) and a new odour annoyance criterion (C-98,C-1-h <= 9.7 ou(E) m(-3)) developed in this study. For a typical size unit in Ireland, maximum setback distances of 660, 665 and 1035 in were calculated for 40,000 broilers, 40,000 layers and 10,000 turkeys respectively at the current limit (C-98,C-1-h <= 6.0 ou(E) m(-3)). However, if the suggested odour impact criterion (C-98,C-1-h <= 9.7 ou(E) m(-3)) is implemented, the maximum setback distances decrease to 460, 500 and 785 in for broilers, layers and turkeys, respectively. 

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Mathematical modelling of domestic water flow

2012-05-13, Prieto Lage, Miguel Ángel, Anders, Yvonne, Bartlett, John, Curran, Thomas P.

A model was developed to simulate water flow with reliable parameters allowing the analysis of water consumption in selected areas. The model was applied to investigate the daily water consumption by domestic users in County Sligo, Ireland. The water flow data was obtained in 15 minute intervals from bulk meters in selected areas. The water consumption data was averaged in different time interval formats and fitted to the model. In all cases, the parameters were consistent (α=0.05) and the correlation coefficients (r2) were high, thus demonstrating the reliability of this approach.

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Predicting atmospheric ammonia dispersion and potential ecological effects using monitored emission rates from an intensive laying hen facility in Ireland

2021-02-15, Kelleghan, David B., Hayes, Enda T., Everard, Mark, Curran, Thomas P.

Agriculture is responsible for 98% of atmospheric ammonia (NH3) in Ireland, of which pigs and poultry produce 7%; with laying hens specifically contributing 0.6%. Though a small proportion of the national NH3 total emissions, the ecological impacts on sensitive sites attributed to laying hen farms can be substantial. NH3 emission monitoring was conducted in Spring (February to March) and Summer (July to August) 2016 to account for seasonal variation. The total average emission and ventilation rate was 0.25 g bird−1 day−1 and 931 cm3 s−1 bird−1. This is lower than the previously used emission factor for the Irish national inventory of 0.5 g bird−1 day−1, but broadly similar to factors reported in the United Kingdom (UK) and the European Union (EU). Dispersion modelling using monitored data indicated potentially acute effects within 84 m, critical level exceedance within 312 m and exceedance of 0.3 kg N ha−1 year−1 deposition within 2.9–5.2 km. The sensitivity of the model was tested using SCAIL-Agriculture emission and ventilation rates which showed P-values for one tailed critical level below 0.01 for all models, indicating that when normalised the maximum extents modelled by AERMOD were significantly different. This analysis showed emission rate having more influence than ventilation rate. Both parameters combined had the greatest increase in dispersion extent, on average 55.8% greater than the use of monitored rates. A deposition rate of 0.3 kg N ha−1 year−1 was modelled to occur within 5.1–7.7 km when using SCAIL-Agriculture rates. Indicating that the use of SCAIL-Agriculture recommended emission and ventilation rates would have been sufficiently precautionary to assess negative ecological effects on a Natura 2000 site under the Habitats Directive (92/43/EEC). In relation to Appropriate Assessment (AA) screening, the use of any contribution from a source within a set distance may be an appropriate full AA trigger.

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Profile of ammonia and water vapor in an Irish broiler production house

2016-06-20, Kelleghan, David B., Hayes, Enda T., Curran, Thomas P.

Ireland produces approximately 8 million broilers annually from 550 farms. In Irish systems, broiler litter is allowed to build up during the 37 day growing cycle, after which it is removed and used for either land spreading or mushroom compost production. It is important to monitor key indoor environmental parameters in order to optimize bird performance but also to comply with legislation such as the EU National Emissions Ceilings Directive. This study used Off Axis - Integrated Cavity Output Spectroscopy to evaluate the ammonia and water vapor content of air within an Irish broiler house. Three broiler cycles were measured at different times of the year to account for seasonal variation, covering spring, summer and autumn. This paper examines the difference in ammonia and water concentrations at 1 m, 2.5 m, and 4 m above floor level following the flow of air from the ground through to the exhaust fan. Autumn had the highest concentration of ammonia indoors throughout the cycle with an average of 1.23 ppm, while summer had the lowest concentration for the majority of the cycle, though increased by a spike towards the end with an average of 0.69 ppm.

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Atmospheric ammonia and nitrogen deposition on Irish Natura 2000 sites: Implications for Irish agriculture

2021-09-15, Kelleghan, David B., Hayes, Enda T., Everard, Mark, Keating, Padraig, Lesniak, Anna, Curran, Thomas P.

With growing global demand for food, the agriculture sector worldwide is under pressure to intensify and expand, risking acceleration of existing negative biodiversity impacts. Agriculture is the dominant source of ammonia (NH3) emissions, which can impact biodiversity directly through dry deposition as NH3 and by wet deposition following conversion to ammonium (NH4) in the atmosphere. Nitrogen deposition is one of the leading causes of global decline in biodiversity alongside changing land use and climate. Natura 2000 sites which are intended to protect important habitats and species across Europe, require strict levels of protection to ensure designated features achieve favourable conservation status. Many of these sites are nitrogen-limited, and/or contain sensitive species such as lichens or mosses. This project carried out ambient NH3 monitoring on selected Irish Natura 2000 sites, in order to establish potential impacts from agricultural NH3. Monitoring on twelve Natura 2000 sites observed concentrations ranging from 0.47 to 4.59 μg NH3 m−3, from which dry deposition was calculated to be 1.22–11.92 kg N ha−1 yr−1. European Monitoring and Evaluation Programme (EMEP) was used to quantify wet deposited NH4 and nitrogen oxides (NOx), in addition to dry deposited NOx on monitored sites. Estimated total nitrogen deposition ranged between 5.93 and 17.78 kg N ha−1 yr−1. On average across all monitored sites, deposition was comprised of 50.4%, 31.7%, 7.5%, and 10.3% dry NH3, wet NH4, dry NOx and wet NOx respectively. Implications for Irish agriculture are discussed in the light of both this monitoring and the European Commission Dutch Nitrogen Case (C 293/17 & C 294/17), highlighting a number of recommendations to aid compliance with the EU Habitats Directive (92/43/EEC).

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Analytical criteria to quantify and compare the antioxidant and pro-oxidant capacity in competition assays: The bell protection function

2014-06, Prieto Lage, Miguel Ángel, Murado García, Miguel Anxo, Vázquez Álvarez, José Antonio, Curran, Thomas P.

The development of a convenient mathematical application for testing the antioxidant and pro-oxidant potential of standard and novel therapeutic agents is essential for the research community and food industry in order to perform more precise evaluations of products and processes. In this work, a simple non-linear dose–time tool to test the effectiveness of compounds for competitive assays is presented. The model helps to describe accurately the antioxidant and pro-oxidant response as a function of time and dose by two criteria values and allows one to perform easily comparisons of both capacities from different compounds. The quantification procedure developed was applied to two well known in vitro competition assays, the β-carotene and crocin bleaching asymptotic reactions. The dose–time dependency of the response of commercial antioxidants and some expected pro-oxidant compounds was evaluated in this study and the results showed low experimental error. In addition, as an illustrative example of the capabilities of the criteria proposed, the quantification of the combined effect of an antioxidant and a pro-oxidant was analyzed. Afterwards, the model was verified for other relevant competitive methods, using available experimental data from the bibliography. Its application is simple, it provides parametric estimates which characterize the response, and it facilitates rigorous comparisons among the effects of different compounds and experimental approaches. In all experimental data tested, the calculated parameters were always statistically significant (Student's t-test, α = 0.05), the equations were consistent (Fisher's F-test) and the goodness of fit coefficient of determination was higher than 0.98.

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Podivny cpavek

2021-12-07, Wright, Nathan T., Kelleghan, David B., Nosek, Stepán, Curran, Thomas P.

This is a comic aimed at children from the age of eight upwards. It highlights impacts from ammonia in agriculture, plus sources and solutions to the problem.

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一个关于氨的故事

2021-12-07, Wright, Nathan T., Kelleghan, David B., Zhang, Kexin, Curran, Thomas P.

This is a comic aimed at children from the age of eight upwards. It highlights impacts from ammonia in agriculture, plus sources and solutions to the problem.

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Predicting freshwater demand on Irish dairy farms using farm data

2017-11-10, Murphy, Eleanor, de Boer, I. J. M, van Middelaar, C. M., Holden, Nicholas M., Curran, Thomas P., Upton, J.

Freshwater use in agriculture is a matter of discussion due to rising concerns over water scarcity, availability and pollution. To make robust predictions of freshwater demand, a large dataset of agricultural data is needed to discern the relationships between production parameters and water demand. The objective of this research was to predict freshwater demand (L yr−1) on Irish dairy farms based on a minimal set of farm data. A detailed water footprint (WF) was calculated for 20 dairy farms for 2014 and 2015, and the relationships between the WF and agricultural inputs explored via a mixed modelling procedure, to develop a minimal footprinting solution. The WF comprised of the consumption of soil moisture due to evapotranspiration (green water, GW) and ground and surface water (blue water, BW). The performance of the models was validated using an independent data set of five dairy farms. The GW model was applied to 221 dairy farms to establish the relationship between the GWF of milk and economic performance. The average total volumetric WF of the 20 farms was 778 L/kg fat and protein corrected milk (L/kg FPCM) (range 415¿1338 L/kg FPCM). Freshwater for pasture production made up 93% of the GW footprint. Grass grown, imported forages and concentrates fed were all significant predictors of GW. The relative prediction error (RPE) of the GW model was 11.3%. Metered on-farm water and concentrates were both significant predictors of BW. The RPE of the BW model was 3.4%. When applied to 221 dairy farms ranked by net margin per hectare, there was a trend (P < 0.05) towards higher profitability as the GWF decreased, indicating that the GWF of dairy farms can be improved by implementing good management practices aligned with improving profitability.

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Biofiltration of n-butyric acid for the control of odour

2003-09, Sheridan, B. A., Curran, Thomas P., Dodd, V. A.

Odour control from pig production facilities is a significant concern due to increased public awareness and the development of more stringent legislation to control production. Although many technologies exist, biofiltration is still the most attractive due to its low maintenance and operating costs. One of the key odour components, n-butyric acid, was selected for a laboratory scale biofilter study. It was examined as a sole carbon substrate in order to investigate the effectiveness of biofiltration in reducing n-butyric acid concentration under different operating conditions using a moist enriched woodchip medium. Three superficial gas velocities; 38.2, 76.4, and 114.6 m h−1 were tested for n-butyric acid concentrations ranging from 0.13 to 3.1 g [n-butyric acid] m−3 [air]. For superficial gas velocities 38.2, 76.4, and 114.6 m h−1, maximum elimination capacities (100% removal) of 148, 113 and 34.4 g m3 h−1, respectively, were achieved. Upon investigation of effective bed height, true elimination capacities (100% removal) of 230, 233 and 103 g m−3 h−1, respectively, were achieved at these superficial gas velocities. Averaged pressure drops for superficial gas velocities 38.2, 76.4, and 114.6 m h−1 were 30, 78 and 120 Pa, respectively. It was concluded that biofiltration is a viable technology for the removal of n-butyric acid from waste exhaust air, but near 100% removal efficiency is required due to the low odour detection threshold for this gaseous compound.