scholarly journals Potential for Ammonia Recapture by Farm Woodlands: Design and Application of a New Experimental Facility

2001 ◽  
Vol 1 ◽  
pp. 791-801 ◽  
Author(s):  
Mark R. Theobald ◽  
Mark C. Milford ◽  
Mark K.J. Hargreaves ◽  
Mark L.J. Sheppard ◽  
Mark E. Nemitz ◽  
...  
Keyword(s):  
Dry Deposition ◽  
Atmospheric Transport ◽  
Low Cost ◽  
Minimum Cost ◽  
Ammonia Concentration ◽  
Control Measures ◽  
Experimental Facility ◽  
Financial Climate ◽  
Farm Woodlands ◽  
Careful Design

There has been increasing pressure on farmers in Europe to reduce the emissions of ammonia from their land. Due to the current financial climate in which farmers have to operate, it is important to identify ammonia control measures that can be adopted with minimum cost. The planting of trees around farmland and buildings has been identified as a potentially effective and low-cost measure to enhance ammonia recapture at a farm level and reduce long-range atmospheric transport. This work assesses experimentally what fraction of ammonia farm woodlands could potentially remove from the atmosphere. We constructed an experimental facility in southern Scotland to simulate a woodland shelterbelt planted in proximity to a small poultry unit. By measuring horizontal and vertical ammonia concentration profiles within the woodland, and comparing this to the concentration of an inert tracer (SF6) we estimate the depletion of ammonia due to dry deposition to the woodland canopy. Together with measurements of mean ammonia concentrations and throughfall fluxes of nitrogen, this information is used to provide a first estimate of the fraction of emitted ammonia that is recaptured by the woodland canopy. Analysis of these data give a lower limit of recapture of emitted ammonia, at the experimental facility, of 3%. By careful design of shelterbelt woodlands this figure could be significantly higher.

Efficiency of uphill locomotion in nocturnal and diurnal lizards

1996 ◽  
Vol 199 (3) ◽  
pp. 587-592 ◽  
Author(s):  
C Farley ◽  
M Emshwiller
Keyword(s):  
Body Mass ◽  
Low Cost ◽  
Minimum Cost ◽  
Mechanical Work ◽  
Energetic Cost ◽  
Cost Of Transport ◽  
Unit Distance ◽  
Cost Of Locomotion ◽  
Average Body Mass ◽  
Average Body

Nocturnal geckos can walk on level ground more economically than diurnal lizards. One hypothesis for why nocturnal geckos have a low cost of locomotion is that they can perform mechanical work during locomotion more efficiently than other lizards. To test this hypothesis, we compared the efficiency of the nocturnal gecko Coleonyx variegatus (average body mass 4.2 g) and the diurnal skink Eumeces skiltonianus (average body mass 4.8 g) when they performed vertical work during uphill locomotion. We measured the rate of oxygen consumption when each species walked on the level and up a 50 slope over a range of speeds. For Coleonyx variegatus, the energetic cost of traveling a unit distance (the minimum cost of transport, Cmin) increased from 1.5 to 2.7 ml O2 kg-1 m-1 between level and uphill locomotion. For Eumeces skiltonianus, Cmin increased from 2.5 to 4.7 ml O2 kg-1 m-1 between level and uphill locomotion. By taking the difference between Cmin for level and uphill locomotion, we found that the efficiency of performing vertical work during locomotion was 37 % for Coleonyx variegatus and 19 % for Eumeces skiltonianus. The similarity between the 1.9-fold difference in vertical efficiency and the 1.7-fold difference in the cost of transport on level ground is consistent with the hypothesis that nocturnal geckos have a lower cost of locomotion than other lizards because they can perform mechanical work during locomotion more efficiently.

scholarly journals Computer-Optimized Weaning Food Blends

1995 ◽  
Vol 16 (3) ◽  
pp. 1-20 ◽  
Author(s):  
R. E. Hayes ◽  
J. M. Mwale ◽  
P. Tembo ◽  
J. I. Wadsworth
Keyword(s):  
Linear Programming ◽  
Amino Acid ◽  
Total Energy ◽  
Essential Amino Acid ◽  
Protein Quality ◽  
Low Cost ◽  
Minimum Cost ◽  
Weaning Food ◽  
Weaning Foods ◽  
Different Seasons

This computerized linear programming study was performed to formulate low-cost, commercially processed, blended weaning foods, and even less expensive, home-prepared, blended wearing foods, with excellent energy and protein value for use in areas of Lusaka, Zambia, where the risk of malnutrition is high. Ingredient input information included proximate and essential amino acid analyses, into-the-blend costs, and factors for gastrointestinal absorption of proteins and total energy. For most computed mixtures, the minimum cost at selected levels of absorbed protein quality was optimized. Formulations were determined, with calculated cost and nutritional parameters, using only mother-favoured ingredients or, alternatively, selections from among all listed market ingredients; fat versus fat plus sugar as concentrated energy; for different seasons (home-prepared); and, for commercial blends, both with and without puridies amino acid(s) that do or do not include vitamin-antioxidant-mineral mix. The methodology should be widely applicable elsewhere.

Waste stabilization ponds and rock filters: solutions for small communities

2007 ◽  
Vol 55 (7) ◽  
pp. 103-107 ◽  
Author(s):  
D.D. Mara ◽  
M.L. Johnson
Keyword(s):  
Rural Communities ◽  
High Performance ◽  
Low Cost ◽  
Water Discharge ◽  
Ammonia Removal ◽  
Control Measures ◽  
Treated Wastewater ◽  
Waste Stabilization Ponds ◽  
Pathogen Reduction ◽  
Crop Irrigation

In temperate climates facultative ponds and rock filters (either unaerated or, if ammonia removal is required, aerated) are a low-cost but high-performance treatment system for small rural communities. Effluent quality is suitable for surface water discharge or, in summer, for restricted crop irrigation. In tropical climates anaerobic and facultative ponds and either unaerated rock filters or, if ammonia reduction is required, subsurface horizontal-flow or vertical-flow constructed wetland, can be used if the effluents are discharged to surface waters. However, if the treated wastewater is to be used for crop irrigation, then a 3-log unit pathogen reduction by treatment in anaerobic, facultative and single maturation ponds is required for both restricted and unrestricted irrigation, provided that, in the case of unrestricted irrigation, there are in place post-treatment health-protection control measures that together provide a further 4-log unit pathogen reduction.

Optimization of the Design of Hydrogen Production Systems Based on Product Cost

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Abdelhamid Mraoui ◽  
Abdallah Khellaf
Keyword(s):  
Hydrogen Production ◽  
Production Systems ◽  
Low Cost ◽  
Minimum Cost ◽  
Total Power ◽  
Photovoltaic Module ◽  
Power Ratio ◽  
The Cost ◽  
Pv Generator ◽  
Practical Constraints

Abstract In this work, the design of a hydrogen production system was optimized for Algiers in Algeria. The system produces hydrogen by electrolysis using a photovoltaic (PV) generator as a source of electricity. All the elements of the system have been modeled to take into account practical constraints. The cost of producing hydrogen has been minimized by varying the total power of the photovoltaic generator. An optimal ratio between the peak power of the PV array and the nominal power of the electrolyzer was determined. Photovoltaic module technology has been varied using a large database of electrical characteristics. It was noted that PV technology does not have a very significant impact on cost. The minimum cost is around 0.44$/N m3, and the power ratio in this case is 1.45. This results in a cost reduction of around 12% compared to a unit ratio. The power ratio and cost are linearly dependent. Only a small number of technologies give a relatively low cost of about 0.35$/N m3. These generators are interesting; however, we assumed an initial cost of $2.00/Wp for all technologies. In addition, it was noted that it is possible to increase hydrogen production by 10% by increasing the power of the photovoltaic generator, the extra cost in this case will only be 0.1%.

scholarly journals Energy Saving and Low-Cost-Oriented Design Processes of Blank’s Dimensions Based on Multi-Objective Optimization Model

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 811 ◽  
Author(s):  
Yongmao Xiao ◽  
Qingshan Gong ◽  
Xiaowu Chen
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Optimization Model ◽  
Low Cost ◽  
Minimum Cost ◽  
Processing Parameters ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Multi Objective ◽  
Set Up

The blank’s dimensions are an important focus of blank design as they largely determine the energy consumption and cost of manufacturing and further processing the blank. To achieve energy saving and low cost during the optimization of blank dimensions design, we established energy consumption and cost objectives in the manufacturing and further processing of blanks by optimizing the parameters. As objectives, we selected the blank’s production and further processing parameters as optimization variables to minimize energy consumption and cost, then set up a multi-objective optimization model. The optimal blank dimension was back calculated using the parameters of the minimum processing energy consumption and minimum cost state, and the model was optimized using the non-dominated genetic algorithm-II (NSGA-II). The effect of designing blank dimension in saving energy and costs is obvious compared with the existing methods.

scholarly journals Direct Measurement of Mercury Deposition at Rural and Suburban Sites in Washington State, USA

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Marc W. Beutel ◽  
Lanka DeSilva ◽  
Louis Amegbletor
Keyword(s):  
Direct Measurement ◽  
Dry Deposition ◽  
Low Cost ◽  
Deposition Velocity ◽  
Washington State ◽  
Rural Site ◽  
Storm Events ◽  
Mercury Deposition ◽  
Spatial And Temporal Patterns ◽  
Atmospheric Concentration

Because of mercury’s (Hg) capacity for long-range transport in the atmosphere, and its tendency to bioaccumulate in aquatic biota, there is a critical need to measure spatial and temporal patterns of Hg atmospheric deposition. Dry deposition of Hg is commonly calculated as the product of a measured atmospheric concentration and an assumed deposition velocity. An alternative is to directly assess Hg deposition via accumulation on surrogate surfaces. Using a direct measurement approach, this study quantified Hg deposition at a rural site (Pullman) and suburban site (Puyallup) in Washington State using simple, low-cost equipment. Dry deposition was measured using an aerodynamic “wet sampler” consisting of a Teflon plate, 35 cm in diameter, holding a thin layer (2.5 mm) of recirculating acidic aqueous receiving solution. In addition, wet Hg deposition was measured using a borosilicate glass funnel with a 20-cm-diameter opening and a 1 L Teflon sampling bottle. Hg deposition was estimated based on changes in total Hg in the aqueous phase of the samplers. Dry Hg deposition was 2.4 ± 1.4 ng/m2·h (average plus/minus standard deviation; n = 4) in Pullman and 1.3 ± 0.3 ng/m2·h (n = 6) in Puyallup. Wet Hg deposition was 7.0 ± 4.8 ng/m2·h (n = 4) in Pullman and 1.1 ± 0.2 ng/m2·h (n = 3) in Puyallup. Relatively high rates of Hg deposition in Pullman were attributed to regional agricultural activities that enhance mercury re-emission and deposition including agricultural harvesting and field burning. Hg concentration in precipitation negatively correlated with precipitation depth, indicating that Hg was scavenged from the atmosphere during the beginning of storm events. Because of their relative simplicity and robustness, direct measurement approaches such as those described in this study are useful in assessing Hg deposition, and for comparing results to less direct estimates and model estimates of Hg deposition.

A New Automatic Readout Circuit for a Gas Sensor With Organic Vertical Nano-Junctions

2016 ◽  
Author(s):  
Hung-Che Chen ◽  
Yung-Hua Kao ◽  
Paul C.-P. Chao ◽  
Chin-Long Wey
Keyword(s):  
Gas Sensor ◽  
Low Cost ◽  
Logic Gate ◽  
Control Unit ◽  
Ammonia Concentration ◽  
Added Value ◽  
Cmos Process ◽  
Readout Circuit ◽  
Readout System ◽  
Operational Errors

The design of the proposed readout circuit provides benefits of detection speed, portability, low-cost and less human operational errors compared with the measurement by traditional instruments. Thus the added value is brought for biosensors and applied in home care. A novel readout circuit for a gas sensor based on an organic diode with vertical nano-junctions (VNJ) is proposed in this study. There are seven parts included in the readout system. First part is a preamplifier, second part is a peak-detect-and-hold circuit, third part is a divider, fourth part is the saturation detector, fifth part is the auto-reset circuit, sixth part is a logic gate and a buffer, seventh part is a micro-processor control unit (MCU). STM32 is the CPU of proposed MCU by ALIENTEK. The ADC of MCU is used to transform the output data of readout circuit. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 μm 2P4M 3.3 V mixed signal CMOS process, the area of chip is 0.74×0.75 mm2. Finally, the differences between experimental results with post-simulation results in 10 ppb ∼ 3 ppm of ammonia, the differences are within 7.24%. The sensing system is able to detect minimum ammonia concentration of 10 ppb, while the maximum one reaches around 3 ppm.

scholarly journals How are NH<sub>3</sub> dry deposition estimates affected by combining the LOTOS-EUROS model with IASI-NH<sub>3</sub> satellite observations?

2018 ◽  
Author(s):  
Shelley C. van der Graaf ◽  
Enrico Dammers ◽  
Martijn Schaap ◽  
Jan Willem Erisman
Keyword(s):  
Dry Deposition ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Deposition Velocity ◽  
Deposition Flux ◽  
Deposition Fluxes ◽  
Po Valley ◽  
Atmospheric Remote Sensing ◽  
Spatial Coverage ◽  
Recent Developments

Abstract. Atmospheric levels of reactive nitrogen have substantially increased during the last century resulting in increased nitrogen deposition to ecosystems, causing harmful effects such as soil acidification, reduction in plant biodiversity and eutrophication in lakes and the ocean. Recent developments in the use of atmospheric remote sensing enabled us to resolve concentration fields of NH3 with larger spatial coverage and these observations may be used to improve the quantification of NH3 deposition. In this paper we use a relatively simple, data-driven method to derive dry deposition fluxes and surface concentrations of NH3 for Europe and for the Netherlands. The aim of this paper is to determine for the applicability and the limitations of this method for NH3 using space-born observations of the Infrared Atmospheric Sounding Interferometer (IASI) and the LOTOS-EUROS atmospheric transport model. The original modelled dry NH3 deposition flux from LOTOS-EUROS and the flux inferred from IASI are compared to indicate areas with large discrepancies between the two and where potential model improvements are needed. The largest differences in derived dry deposition fluxes occur in large parts of Central Europe, where the satellite-observed NH3 concentrations are higher than the modelled ones, and in Switzerland, northern Italy (Po Valley) and southern Turkey, where the modelled NH3 concentrations are higher than the satellite-observed ones. A sensitivity analysis of 8 model input parameters important for NH3 dry deposition modelling showed that the IASI-derived dry NH3 deposition fluxes may vary from ~ 20 % up to ~ 50 % throughout Europe. Variations in the dry deposition velocity used for NH3 led to the largest deviations in the IASI-derived dry NH3 deposition flux and should be focused on in the future. A comparison of NH3 surface concentrations with in-situ measurements of several established networks (EMEP, MAN and LML) showed no significant, or consistent improvement in the IASI-derived NH3 surface concentrations compared to the originally modelled NH3 surface concentrations from LOTOS-EUROS. It is concluded that the IASI-derived NH3 deposition fluxes do not show strong improvements compared to modelled NH3 deposition fluxes and there is future need for better, more robust, methods to derive NH3 dry deposition fluxes.

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