4,315 research outputs found
Simulation of site-specific irrigation control strategies with sparse input data
Crop and irrigation water use efficiencies may be improved by managing irrigation application timing and volumes using physical and agronomic principles. However, the crop water requirement may be spatially variable due to different soil properties and genetic variations in the crop across the field. Adaptive control strategies can be used to locally control water applications in response to in-field temporal and spatial variability with the aim of maximising both crop development and water use efficiency. A simulation framework ‘VARIwise’ has been created to aid the development, evaluation and management of spatially and temporally varied adaptive irrigation control strategies (McCarthy et al., 2010). VARIwise enables alternative control strategies to be simulated with different crop and environmental conditions and at a range of spatial resolutions.
An iterative learning controller and model predictive controller have been implemented in VARIwise to improve the irrigation of cotton. The iterative learning control strategy involves using the soil moisture response to the previous irrigation volume to adjust the applied irrigation volume applied at the next irrigation event. For field implementation this controller has low data requirements as only soil moisture data is required after each irrigation event. In contrast, a model predictive controller has high data requirements as measured soil and plant data are required at a high spatial resolution in a field implementation. Model predictive control involves using a calibrated model to determine the irrigation application and/or timing which results in the highest predicted yield or water use efficiency. The implementation of these strategies is described and a case study is presented to demonstrate the operation of the strategies with various levels of data availability. It is concluded that in situations of sparse data, the iterative learning controller performs significantly better than a model predictive controller
Air pollution and livestock production
The air in a livestock farming environment contains high concentrations of dust particles and gaseous pollutants. The total inhalable dust can enter the nose and mouth during normal breathing and the thoracic dust can reach into the lungs. However, it is the respirable dust particles that can penetrate further into the gas-exchange region, making it the most hazardous dust component. Prolonged exposure to high concentrations of dust particles can lead to respiratory health issues for both livestock and farming staff. Ammonia, an example of a gaseous pollutant, is derived from the decomposition of nitrous compounds. Increased exposure to ammonia may also have an effect on the health of humans and livestock. There are a number of technologies available to ensure exposure to these pollutants is minimised. Through proactive means, (the optimal design and management of livestock buildings) air quality can be improved to reduce the likelihood of risks associated with sub-optimal air quality. Once air problems have taken hold, other reduction methods need to be applied utilising a more reactive approach. A key requirement for the control of concentration and exposure of airborne pollutants to an acceptable level is to be able to conduct real-time measurements of these pollutants. This paper provides a review of airborne pollution including methods to both measure and control the concentration of pollutants in livestock buildings
Energy Efficient Window Development
The paper investigates the development of energy efficient windows in the past 30 years. The focus is on the development and interlinkages among technology, actors´ interaction and market diffusion in a broader policy context. The paper shows that in singular development cycles, different factors and the interfaces among these factors influenced the improvement and penetration of energy efficient window technologies. Such factors includes a) surrounding factors, such as climate characteristics, oil crisis and international concerns and strategies, b) policy instruments, like building codes and technology procurement programs, as well as c) industry initiatives, including niche market strategies
The second energy R & D programme. Energy conservation (1979-83). Survey of results. EUR 8661 EN. Energy
Advanced Industrial Materials (AIM) Program Compilation of Project Summaries and Significant Accomplishments FY 1999
Manufacturing process applications team (MATeam)
Activities of the manufacturing applications team (MATeam) in effecting widespread transfer of NASA technology to aid in the solution of manufacturing problems in the industrial sector are described. During the program's first year of operation, 450 companies, industry associations, and government agencies were contacted, 150 manufacturing problems were documented, and 20 potential technology transfers were identified. Although none of the technology transfers has been commercialized and put in use, several are in the applications engineering phase, and others are in the early stages of implementation. The technology transfer process is described and guidelines used for the preparation of problems statements are included
The Application of Microwave Energy in Mineral Processing – a Review
This paper presents a review of the application of microwave energy in the field of mineral processing at the Institute of Geotechnics,Slovak Academy of Sciences. The influence of microwave radiation of rocks on the failure disintegration of minerals and ores as well as,a modification of magnetic properties and thermal processing of rocks was studied. Moreover, the rate of microwave heating of minerals,effect of microwaves on coal desulphurisation and the extraction of diterpanes from coal were investigated
Economic and environmental analysis of energy efficiency measures in agriculture. Case Studies and trade offs.
This report is the result of the collaboration of the partners of the AGREE work-package “Economic and environmental analysis”, which is based on case study analyses of the partners in seven countries of the EU. The case studies show economic and environmental trade-offs in the different regions in the EU, for which each partner is responsible. Nevertheless prior to the reporting of the case studies an intensive discussion on a common methodological approach has been accomplished and applied to the case studies. The case studies show a wide range of different perspectives of energy efficiency in agriculture, but they are all based on the common methodology presented in Chapter 3. In Chapter 4, the case studies are presented, with authors indicated at the beginning of each section. Each section of Chapter 4 ends with a synthesis analysis of the results from the different case studies. Chapter 5 summarizes and concludes the report by highlighting the major findings of the analyses.
The report builds upon the “State of the Art in Energy Efficiency in Europe” published separately by the AGREE consortium (Gołaszewski et al. 2012), which shows the status quo of energy use and possible energy efficiency measures in agriculture across different production systems and regions in Europe. This report presents an economic and environmental analysis based on in-depth case studies which show the potential for, and constraints on, energy efficiency measures in agriculture with respect to the specific environments in Europe
Electric motor selection
"4/83/5M""Electric motors are used for a multitude of tasks. The use of this equipment has relieved us from tedious and time-consuming chores. For example, a 1 horsepower (HP) motor that is about 75 percent efficient will consume approximately 1,000 watts. Thus, a general rule for electric motors is 1 horsepower-hour equals 1 kilowatt-hour. One horsepower-hour is equivalent to one person working 10 hours. A 1 HP motor can do in one hour for about 6[cents] what it would take a person about 10 hours to do. Electric motors will continue to be used for new jobs around the farm as long as the price and scarcity of labor continue to increase. Once you determine that a motor is required for a particular task, you must decide on one of a variety of types, classes, efficiencies, and makes. This booklet provides an explanation of the various terms used and compared different electric motors."--Page 1.Missouri Farm Electrification Council, Inc., Cooperative Extension Service University of Missouri--Columbia
Dynamic Modeling of Kilning Process in Matlab & Simulink Environment
Hlavním cílem této práce je simulace závěrečné fáze procesu sladování - hvozdění. K tomuto účelu je v práci analyzován a následně použit model jednolískového kruhového hvozdu v Simulinku (model vlastní společnost Bühler). Teoretická část popisuje všechny úseky výroby sladu včetně zařízení používaného v moderní sladovně. Proces hvozdění je podrobně popsán v samostatné kapitole. Praktická část je věnována simulaci procesu hvozdění. Nejprve se práce zaměřuje na analýzu modelu, jeho modifikaci a nastavení podle vybraného skutečného hvozdu. Následuje verifikace modelu pro různé receptury hvozdění a za různých okolních podmínek porovnáním simulovaných hodnot s měřením. Práce pokračuje návrhy, jak lze model použít pro dimenzování ohřívačů vzduchu a ventilátorů. Nakonec se praktická část zabývá různými možnostmi snížení spotřeby tepelné a elektrické energie. Na základě výsledků simulace vzniká závislost mezi spotřebou energie a dobou procesu.The main aim of this work is to simulate and analyse the final phase of the malting process - kilning. For this purpose, the Simulink model of a single-deck circular kiln is used (owned by Bühler). The theoretical part describes all the steps of the malt production including the equipment commonly used in a modern malt house. The kilning process is described in detail in a separate chapter. The practical part is dedicated to the simulation of the kilning process. Firstly, the thesis focuses on the model analysis, its modification and setting according to the selected real kiln. Then the model verification follows, using different kilning recipes and under different ambient conditions by comparing simulated values with measurements. The work continues with suggestions how the model can be used for the dimensioning of air heaters and fans. Finally, the practical part deals with various possibilities for reducing the thermal and electric energy consumption. Based on the simulation results, the relationship between the energy consumption and process time is described
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