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1
Gjata, Nerta. "Food Web Simulation Studies on Aquatic Ecosystems." Doctoral thesis, Università degli studi di Trento, 2013. https://hdl.handle.net/11572/367707.
Full textAbstract:
There is an increasing interest in dynamical food web modeling, and recent advances of computational biology provide new algorithms and tools for modern systems ecology.
In this work stochastic individual-based models are used for simulating food web dynamics in two case studies: the Kelian river, in Borneo, Indonesia and a marine ecosystem in Gulf of Guinea. The two cases present effects from human perturbations. In both cases, we constructed food webs, based on real databases. We parameterized the stochastic dynamical model for the system models and performed sensitivity analysis (and community response indicators) in order to quantify the relative importance of system components.
The main aims are to understand the importance of functional diversity of aquatic ecosystems and relations between the dynamics of species and the whole community in perturbed ecosystems due to human activities (pollution due to gold mining activity and human settlements in the case of the Kelian river ecosystem and the impact of Fish Aggregation Devices on skipjack tuna communities in the case of the Gulf of Guinea ecosystem).
In Kelian river case, our results suggest that invertebrate shredders are indicators of human impact on the river. In downstream sites our results show that the river is more polluted and the relative importance of grazers and shredders decrease. The primary producers disappear downstream as consequence of mine activity and human waste.
In the marine system case study, we analyzed the effects of association between tunas and FADs, and compared this to the behavior of free tuna individuals. The results suggest that skipjack tuna is affected by the use of FADs as fishing strategy on them. Some individual species show more sensibility to variation of population size of tuna.
These two studies contribute to better understand how functional diversity is related to human impact. This kind of approach may help in shaping systems-based conservation and marine fisheries management strategies.
Keywords: food web, aquatic ecosystems, stochastic model,
sensitivity analysis
2
Gjata, Nerta. "Food Web Simulation Studies on Aquatic Ecosystems." Doctoral thesis, University of Trento, 2013. http://eprints-phd.biblio.unitn.it/1140/1/TesiN_Gjata.pdf.
Full textAbstract:
There is an increasing interest in dynamical food web modeling, and recent advances of computational biology provide new algorithms and tools for modern systems ecology.
In this work stochastic individual-based models are used for simulating food web dynamics in two case studies: the Kelian river, in Borneo, Indonesia and a marine ecosystem in Gulf of Guinea. The two cases present effects from human perturbations. In both cases, we constructed food webs, based on real databases. We parameterized the stochastic dynamical model for the system models and performed sensitivity analysis (and community response indicators) in order to quantify the relative importance of system components.
The main aims are to understand the importance of functional diversity of aquatic ecosystems and relations between the dynamics of species and the whole community in perturbed ecosystems due to human activities (pollution due to gold mining activity and human settlements in the case of the Kelian river ecosystem and the impact of Fish Aggregation Devices on skipjack tuna communities in the case of the Gulf of Guinea ecosystem).
In Kelian river case, our results suggest that invertebrate shredders are indicators of human impact on the river. In downstream sites our results show that the river is more polluted and the relative importance of grazers and shredders decrease. The primary producers disappear downstream as consequence of mine activity and human waste.
In the marine system case study, we analyzed the effects of association between tunas and FADs, and compared this to the behavior of free tuna individuals. The results suggest that skipjack tuna is affected by the use of FADs as fishing strategy on them. Some individual species show more sensibility to variation of population size of tuna.
These two studies contribute to better understand how functional diversity is related to human impact. This kind of approach may help in shaping systems-based conservation and marine fisheries management strategies.
Keywords: food web, aquatic ecosystems, stochastic model,
sensitivity analysis
3
Bewaji-Adedeji, Eniola Olsimbo. "The development of a general-purpose dynamic simulator for food process design and simulation." Thesis, London South Bank University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245070.
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Kassim, Hamida Omowunmi. "The development of simulation models for food process operations." Thesis, London South Bank University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245061.
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The development of a simulation strategy and modelling algorithm with potential application to a variety of food process operations, particularly to thermal processing of canned foodstuffs has been undertaken. A review of published work identified previous efforts in the development of mathematical models for thennal process operations, including their limitations. The review showed that Finite Difference methods have found wide application in modelling conduction heating of canned foods. A similar model would be a useful numerical yardstick for validating any developments in this work. The great diversity of food handling operations have been grouped into a more manageable small number of classes. Such classification recognised that sets of related operations share common characteristics and functions which are the basis for the development of mathematical models for each class of operations. The strategy developed involved hierarchical decomposition of unit operations into assemblies of basic modules and mathematical modelling of these basics. A model of the operation can then be constructed simply by selecting and arranging the required basic units with due consideration to the boundary conditions of the physical problem. For transient operations with positional variation, these elementary modules have been termed "zones". The range of basic zones to model representative units have been identified. This hierarchical zone-model simulation has been demonstrated for heat transfer in a cylindrical container and for batch retort operation. The repeated use of the same unit modules for different operations makes this a flexible and robust strategy. The mathematics of zone-modelling has been developed for heat conduction in foodstuffs in cylindrical containers. To ensure accuracy, the numerical integration steps were rigorously monitored using mathematical procedures well-established for this purpose. The validity of the model has been tested against the analytical and implicit finite difference solutions. Generally, zone models agreed within 1 % of these standard yardsticks with the difference becoming negligible when sufficiently small integration steps or zone sizes were used. The effectiveness of zone-modelling as a simulation tool has been established using experimental data and the various sources of discrepancy between the model and experimental data accounted for. Thermocouple measurement errors have been found to have contributed most significantly to this discrepancy. Detailed analysis and modelling of thermocouple measurement errors has been carried out using zone-modelling to simulate the true experimental system which accounted for the presence of a thermocouple. The result has been an improved agreement between experiment and the zonemodel, and it also demonstrated the flexibility of the modelling technique. Further resuhs have shown that the discrepancy varied with thermocouple size and type. The contributions to error of temperature variability of, and of uncertainty in, thermophysical properties of the food were discussed. , The flexibility and robustness of zone-modelling have been further demonstrated using some practical situations including heat transfer to foodstuff in flexible packaging - such as sausage rolls, heat transfer in a food container with varying headspaces and the consequence of steam interruption during processing. Examples have been discussed of other transient processes that could similarly be modelled using this technique. The main achievements of this work include the application of hierarchical simulation and zonemodelling techniques to food processing and the development of a novel mathematical modelling technique which is more flexible than finite differences. Moreover, the applications of zonemodelling to the study of thermocouple errors, to the study of the consequences of steam interruption during thermal processing, and to heat transfer in foods in flexible containers, are developments of interest in food processing. It is concluded that the hierarchical simulation and zone modelling algorithm are robust and flexible techniques with potential applications in food process simulation .
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Behara, R. S. "A simulation study of food delivery in cafeteria services." Thesis, Manchester Metropolitan University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235270.
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Blanchard, Jacquelyn. "Simulation of Refrigerated Food Quality during Storage and Distribution." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587045898641609.
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Ghosh, Supriyo. "SIMULATION, NETWORK MODELING, AND IMAGING OF POROUS MEDIA DRYING." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-12112006-103136/.
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Drying is a unit operation where water is removed from a material by means of evaporation and mass transfer. It is widely used in industrial manufacturing processes. Many of these processes involve drying of porous materials. Porous media are, in general, heterogeneous systems. The microstructure of the pore space influences transport properties and hence, drying rates. Thus, a quantitative geometrical characterization of the pore space is crucial for accurate prediction of porous media drying rates. Simulation of porous media structure, given a specific size distribution of constituent particles, followed by pore-space characterization is a powerful as well as economical predictive tool for product design. Realistic unconsolidated porous media were reconstructed through Monte Carlo gravitational particle packing simulation. The porous media simulation was validated by comparison with extracted transport related micro-structural parameters from x-ray micro-CT (computed tomographic) images. A mathematical morphology based three-dimensional image processing algorithm was developed to characterize the pore space in the simulated porous media. This realistic pore-throat network information was utilized in an invasion percolation based simulation of porous media drying and showed satisfactory agreement with quantitative data extracted from in-situ NMR (nuclear magnetic resonance) imaging experiments.
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Soydan, Karabacak Meltem. "Finite Element Modelling And Simulation Of Drying Isotropic And Anisotropic Food Samples." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615618/index.pdf.
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The aim of this study was to investigate drying characteristics (temperature gradient, rate of drying and temperature change, drying time, diffusivity values, shrinkage) of isotropic and anisotropic foods by observing the changes in temperatures at four different locations and moisture contents and to build an appropriate model for simulation of temperature and moisture distribution using finite element method. The lean meat samples (anisotropic) with three fiber configurations (vflow normal to fiber, drying along the fiber, h1
flow normal to fiber, h2
flow along to fiber) and minced meat (isotropic) were dried at two different temperatures (48
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Sandoval, Diana, Manuela Palomares, Jose Rojas, Pablo Mendoza, and Carlos Raymundo. "Lean Thinking Simulation Model to Improve the Service Performance in Fast Food." Advances in Intelligent Systems and Computing, 2021. http://hdl.handle.net/10757/653849.
Full textAbstract:
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.The fast food industry, specifically the service department, has experienced sustainable economic growth and has evolved in the application of substantial methods, however, it has presented a slowdown due to deficient operation level provided in the customer service area. A large number of customers do not make the purchase owing to a series of unmet trends that face the consumer behaviour which leads to significant economic losses and inefficient service. They have therefore focused their efforts on finding impulse mechanisms through allowing them to migrate to less costly processes and/or to achieve better utilisation of available resources without success. This research inquires into the effectiveness of the Lean Thinking Simulation (LTS) model, which consists in the development of a set of methodological phases and the adaptation of the technological support termed as Digital Change to improve the performance of customer service in Peruvian fast food. The main result of this practical study was defined by a Dashboard in real-time, and as a first approximation of the model, a 17.03% improvement can be shown in the performance of customer service on the fast food selected.
Revisión por pares
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COLETTO, MAURICIO MIGUEL. "Atmospheric Freeze Drying of Food in Fluidized Beds - Practical aspects and CFD simulation." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2588248.
Full textAbstract:
Atmospheric freeze drying (AFD) is the lyophilization of a product at atmospheric pressure conditions and temperatures ranging generally between -15 and -5 ◦C (avoiding, thereby, ice melting). The quality of the obtained dried products is quite similar to the quality of products dried by vacuum freeze drying (VFD), but without the need of generating vacuum, maintaining temperatures around -50 ◦C in the condenser, or defrosting it.
There are several ways to carry out AFD, such as the use of a fluidized bed or a tunnel conveyor. Nevertheless, AFD involves considerably longer drying times than VFD, and the process must be modified in some way in order to shorten them without loss of product quality at the same time. Moreover, since this process is usually carried out with air at very low temperatures, it can saturate rapidly. This situation leads to a reduction of the gradient of water concentration between air and product surface, and consequently, a diminution of the mass transfer rate.
The use of an adsorbent material compatible with the food product (i.e., not toxic for human consumption) in a fluidized bed, could constitute an alternative for using other extra energy supplies (such as IR application, or heat pump). At the same time, the use of the adsorbent medium presents two additional advantages: the first, as the heat of adsorption of water vapour is of the same order of magnitude than sublimation heat of ice, no additional energy supply is necessary; second, it acts as adsorbent medium for generated water vapour, allowing air recirculation, which means an additional reduction of operative costs.
In particular, non-food wheat bran is an interesting material to be applied as adsorbent in this process; this adsorbent is not only compatible with foodstuff, but also, since it is a by-product of the cereal processing industry, it is cheap and can be easily discarded (and reused, for example, in compost) without recovering it by means of a thermal treatment. Nonetheless, as it is the hard outer layer of cereals consisting of combined aleurone and pericarp, its particles exhibit a very irregular plane shape, with rests of grain brush and, in some cases, broken pericarp. These characteristics confer to the particle a rough surface and, as undesired consequence, the possibility of mechanical interaction during fluidization.
However, when two different materials are fluidized in a fluidized bed, the mixture may undergo segregation, causing a poor contact between the adsorbent and the food particles. Thus, instead of using a traditional fluidized bed, a spout-fluid bed (an apparatus similar to the spouted bed, with lateral air injectors beside the main jet) may be utilized, and thereby enhancing mixing.
On the other hand, CFD simulation would offer a great potential for simulating the AFD process, its optimization from the fluid dynamic point of view, and the design of new equipment. Various investigators have been working on the application of CFD models for simulating AFD in fluidized bed. However, in general, they simulated a single piece of foodstuff, but not the complete system with air, food material, and adsorbent (when it is applied).
The general objectives of the PhD work are to determine the hydrodynamic conditions under which AFD in adsorbent fluidized bed is feasible, and to obtain a first approach to a CFD model of the process. Particularly, the study of the hydrodynamics of the process (non-food wheat bran fluidization behaviour, and mixing of binary mixtures) in a fluidized bed as well as in a spout-fluid bed is aimed from the experimental point of view, while the evaluation of the possibility of simulation by means of a CFD code of the AFD process by immersion in adsorbent medium in a fluidized bed is intended in the theoretical field.
Unlike sand or other materials in which regular bubbles are formed, non-food wheat bran exhibits canalization or preferential air paths formation, and bed does not expand after overcoming minimum fluidization velocity. In addition, bran particle diameter is represented by a population distribution whose majority is Geldart B. Therefore, considering other bran particles physical characteristics such as rough surface and rest of grain brushes, it can be said that this "pseudo-cohesive" behaviour is caused principally by mechanical interactions rather than electrostatic forces as occurs in cohesive powders.
In general terms, it can be observed a cyclical behaviour of channels generation and collapse. The number of channels and their shape depend on air superficial velocity as well as the bed position where they are formed. Anyway, in general they follow the Channel Generation and Collapse Cycle where two main stages are represented: I, generation, and II, collapse.
Experiments emulating different stages of the AFD process with adsorbent application (using fresh food, partially lyophilized material, and completely lyophilized foodstuff) were done employing different food particles (peas, carrot discs, and potato slabs). Experiments were carried out in a 35 cm squared base fluidized bed and in a 20x10 rectangle base fluid-spout bed. The effects on segregation of air superficial velocity, product volumetric fraction, and particle shape were evaluated.
For evaluating the segregation, segregation indexes form literature were evaluated, but some difficulties were found using them, besides it is not possible to obtain information about the segregation profiles with them. Thus, a novel way for characterizing segregation was proposed (the Three Thirds Segregation Indexes Set, TTSIS), consisting of three numbers that evaluate the distribution profile of a material of interest (food product, for the current case) and a fourth one that gives an idea of the segregation level. TTSIS was found the best tool for quantifying the segregation phenomenon, as it allows not only to measure the segregation level, but also classify the segregation pattern.
As it was expected from the theory, it was evidenced that, even for a binary mixture composed by a pseudo-cohesive powder and a solid whose particles are considerably greater than the powder ones, the air superficial velocity plays a very important role in mixing. Particularly, at high air flows (2.6 umf-adsorbent for the analysed cases) uniform distribution of the material of interest are reached when dried foodstuff is used. Nonetheless, product density plays a fundamental role, since disuniform segregation profiles were obtained when fresh or partially lyophilized food material was used. Uniform mixing profiles were reached in the fluid-spout bed with a good circulation of the food particles along the bed during the fluidization. These results shown to be independent of the product density. Thus, this kind of bed should be used if an uniform mixing between adsorbent and food product is desired.
Segregation phenomenon in channelling fluidized beds and the mixing process in fluid-spout beds might be explained by means of two food particle transport mechanisms (passive and active) and two movement blocking effects (floor and roof effects) observed during experimentation (video analysis), and the Channel Generation and Collapse Cycle.
Regarding to CFD simulations, relatively reasonable results were obtained from the hydrodynamic point of view only at high air superficial velocity. However, specific models for cohesive or pseudo-cohesive powders are required if an accurate simulation of this kind of solids or binary mixtures integrated by them is intended.
In sum, from the experimental results, emerged that the fresh product completely segregates toward the bed bottom in fluidized bed when mixtures containing food material without drying were used. Thus, a good contact between the material to be dried and the adsorbent (desirable for utilizing the adsorption heat for ice sublimation) would be not possible for AFD with use of adsorbent in fluidized bed applications. In contrast, using a fluid-spout bed maintains a very good mixing even if fresh food particles are used. Thus, beside the already known applications of this kind of beds for catalytic processes, its utilization for AFD with adsorbent medium seems to be an interesting and novel option for this process.
Nevertheless, CFD simulation might be performed only for non-cohesive powders since the simulation of pseudo-cohesive materials fluidization is currently limited because of the lack of hydrodynamic models for this kind of solids.
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Chen, Hao. "Computer simulation of combined microwave and water heating processes for packaged foods using finite difference time domain method." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Dissertations/Spring2008/h_chen_031008.pdf.
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Chen, Cuiren 1962. "Application of computer simulation and artificial intelligence technologies for modeling and optimization of food thermal processing." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37877.
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The major objective of this project was to evaluate the feasibility of artificial neural networks (ANNs) and genetic algorithms (GAs) for modeling and optimization of food thermal processing. The specific objectives were: (1) to develop a comprehensive computer simulation program for thermal processing, (2) to apply ANNs and GAs for modeling and optimization of constant retort temperature (CRT) thermal processing and variable retort temperature (VRT) thermal processing, (3) to develop dynamic models for thermal processing using ANNs, and (4) to explore ANN-model-based analysis of critical control points for deviant thermal processes.As a preliminary research, neural network models were successfully developed for modeling of residence time distribution (RTD) under aseptic processing conditions. The main configuration parameters of neural networks such as the number of hidden layers and their neurons, learning runs, choice of transfer functions and learning rules were optimized.
In order to provide experimental data needed for developing and testing of ANN models and GA optimization, a comprehensive finite difference computer simulation program for thermal processing was first developed in MS Visual Basic language, which could be used for simulating different thermal processes such as constant retort temperature (CRT) and variable retort temperature (VRT) thermal processing.
The second objective was focused on developing modeling and optimization methods for CRT thermal processing using ANNs and GAs. The ANN models were developed for predicting process time, average quality retention, surface cook value, final temperature difference, lethality ratio, and equivalent energy consumption. Using this optimization program, the effects of process variables on the optimal retort temperature and the maximum average quality retention were investigated.
The final part of the thesis research was focused on applying ANN methods for the analysis of critical control points (CCPs) for deviant thermal processes, one of the important steps required for developing hazard analysis of critical control points (HACCP) program. The results indicated that ANN models could be efficiently used for the analysis of CCPs of thermal processing. Such a concept can be expanded for developing an ANN based HACCP expert system for thermal processing. (Abstract shortened by UMI.)
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Shan, Shengyue. "The Optimization of the Tempering Process for a Pork Belly Product on the Basis of Physical Property Simulation." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563554049641523.
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Moreira, da Silva Maria da Conceicao Barbosa. "Optimization of a continuous membrane bioreactor for the saccharification of starch using temperature as a control variable : experimental study and simulation analysis." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280323.
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Edi-Soetaredjo, Felycia. "Numerical simulation of twin-screw extrusion of starch based material /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18502.pdf.
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Stone, James B. "Simulation of Temperature and Texture During Thawing of Par-Baked Crust." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1499611846591832.
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Tiwari, Gopal. "Computer simulation of radio frequency (RF) heating in dry food materials and quality evaluation of RF treated persimmons." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Dissertations/Spring2010/g_tiwari_041910.pdf.
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Saad, Zoubeir. "Simulation of temperature history and estimation of thermal properties of food materials during freezing." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-02132009-170810/.
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Mahiuddin, Md. "Mechanical characterizing and drying simulation of plant-based food materials: The fractional model approach." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/204285/1/Md_Mahiuddin_Thesis.pdf.
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Food processing industry is one of the largest manufacturing sectors in Australia. Drying is one of the major processes in food industry that reduces food waste by increasing shelf-life. However, drying is highly energy-intensive lengthy process and results in significant quality deterioration. To retain the fresh like quality and reduce the energy consumption, a comprehensive understanding of transport process during drying is essential. To overcome the limitations of current mathematical models, this study introduced new fractional differential models for mechanical characterising and drying simulation of food materials. These models can be applied in many areas outside food drying.
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Lakhani, Muhammad Bashir 1960. "Simulation of pecan processing for evaluation of process alternatives." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282370.
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A number of alternatives were considered to keep pecan processing economically competitive and sustainable. The industry needed a low risk evaluation technique for testing new high capital plant configurations. A simulation model was developed using the AweSimTM simulation system to form the model structure and framework. The Visual SLAMTM and Visual BASIC programming languages were used to build a network model that provided a mathematical-logical representation of the system. The model mathematically expresses all sub-processes including moisture conditioning, pasteurizing, cracking, shelling, sizing, manual and electronic sorting, resizing, resorting, and packaging. The pecan process simulation model consists of 24 RESOURCES, 353 ACTIVITIES, 48 AWAIT/QUEUE and FREE nodes, 83 BATCH and UNBATCH nodes, 79 ASSIGN nodes, 20 COLCT nodes, 39 GOON nodes, 10 other miscellaneous nodes and a graphic user interface (GUI). The model provides information on equipment utilization, delays, queues and bottlenecks for each process in the system. It also predicts total pecan cracked and total pecan packed, including details of production for each size class i.e. halves; large; medium; small; midget; fine; granule; and oil stock. The model was validated quantitatively by comparing output with actual production figures and qualitatively by plant management. Five options of process alternatives were simulated using the pecan simulation model. The first alternative (including 3 options) was a management proposed configuration for dual electronic sorting of pecan halves to reduce the shell pieces and ensure a lighter color product. Two options were found not viable as they required major capital investments and plant reconfiguration. The third option for dual sorting was found to be a viable process alternative with minor labor additions.
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Al-Obaidi, Mudhar A. A. R. "Modelling, Simulation, and Optimisation of Reverse Osmosis Process with Application in Wastewater Treatment and Food Processing." Thesis, University of Bradford, 2018. http://hdl.handle.net/10454/17345.
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Reverse Osmosis (RO) is a membrane-based separation process applied in several industrial and food processing applications. In this research, performance of RO process is investigated in respect of two applications (a) wastewater treatment (b) concentration fruit juices using model-based techniques. For this purpose, a number of models (both 1 and 2-dimensional steady state and dynamic) for spiral wound RO process are developed based on Solution-Diffusion model and Irreversible Thermodynamic model. The models are validated against actual experimental data reported in the literature before being used in further simulation and optimisation studies for both wastewater treatment and fruit juice concentration. Wastewater effluents of many industrial applications contain a variety of micro-pollutants and highly-toxic compounds, which are released into a variety of water resources. Such pollutants not only disrupt the biological ecosystem, but they also pose a real threat to the water supply for human consumption and to the aquatic ecosystems. The earlier chapters of the thesis evaluate the performance of RO process in terms of removal efficiency of toxic compounds such as chlorophenol, N-nitrosamine, etc. from wastewater. The effect of several operating parameters such as feed pressure, concentration, flow rate and temperature, on the performance of RO process are evaluated. Also, suitability of a number of different RO configurations for efficient removal of toxic compounds are evaluated. For example, (a) two-stage/two-pass RO design synthesis of RO network for the removal of chlorophenol (b) multistage multi-pass RO process with and without energy recovery option for the removal of N-nitrosamine are investigated. The dynamic response of the RO process for step changes in the operating parameters is investigated for the removal of phenolic compounds. Finally, in the context of wastewater treatment, a case study with multi compounds contaminants is suggested where a multi-objective optimisation problem has achieved the optimum rejection of all the compounds and recovery rate. In respect of food processing, RO has been considered as a prominent process in fruit juice concentration due to its ability to effectively retain the flavour, sensory, aroma and nutritional characteristics and concentrate the juice. This research elucidates one example of apple juice concentration process and focuses on highlighting successful modelling and optimisation methodology. This in turn provides an efficient method of RO process for concentrating apple juice by improving the reliability and efficiency of the underlying separation and concentration process.Ministry of High Education and Scientific Research of Iraq
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Karunasena, H. C. P. "Numerical simulation of micro-scale morphological changes of plant food materials during drying: A meshfree approach." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/76526/1/H.C.P.%20Karunasena%20Thesis.pdf.
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This thesis developed a high preforming alternative numerical technique to investigate microscale morphological changes of plant food materials during drying. The technique is based on a novel meshfree method, and is more capable of modeling large deformations of multiphase problem domains, when compared with conventional grid-based numerical modeling techniques. The developed cellular model can effectively replicate dried tissue morphological changes such as shrinkage and cell wall wrinkling, as influenced by moisture reduction and turgor loss.
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Ghazala, Suad. "Degradation kinetics of quality factors, their verification and optimization in a thermoprocessed simulated food system." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74358.
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A novel simulated food model (ascorbic acid, thiamine and a mixture of glucose and glycine) incorporating celite was developed. Basic kinetic parameters were established and the analysis of this data led to a reconsideration of the fundamental aspects relating the TDT and Arrhenius systems of evaluating kinetic parameters and their meaning. Heat penetration data was obtained for both conduction and convection systems, with the conduction system being characterized by parameters calculated from the heat penetration data. Stainless steel micro-capsules were used to isolate and obtain centerpoint nutrient destruction and compared it to the predictions of two computer models. Computer models were tested and verified for the conduction system and an optimization technique based on a multi-factor objective function evaluated.Celite simulated a typical conduction system and the kinetics of quality factor degradation varied depending on composition. Centerpoint capsules worked well in evaluating nutrient destruction and provided a means for verifying computer simulations. Predictions from the Teixeira and Ball models indicated that the Teixeira model was a better process predictor. Multi-factor objective functions for maximizing nutrient retention were shown to work well in defining optimal conditions using the Teixeira program, while those based on the Ball model were indeterminate.
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Quayesam, Dennis. "The Food Truck Problem, Supply Chains and Extensions of the Newsvendor Problem." Digital Commons @ East Tennessee State University, 2021. https://dc.etsu.edu/etd/3905.
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Inventory control is important to ensuring sufficient quantities of items are available tomeet demands of customers. The Newsvendor problem is a model used in Operations Research to determine optimal inventory levels for fulfilling future demands. Our study extends the newsvendor problem to a food truck problem. We used simulation to show that the food truck does not reduce to a newsvendor problem if demand depends on exogenous factors such temperature, time etc. We formulate the food truck problem as a multi-product multi-period linear program and found the dual for a single item. We use Discrete Event Simulation to solve the stochastic version of the dual and found the optimal order to maximize the food vendors profit.
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Chi, Minli 1965. "Development of virtual laboratory as an educationalresearch tool in food processing." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111501.
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Personal computers (PC) and high level programming techniques have been developing so rapidly during last decade leading to new and exciting opportunities in the field of education. The purpose of this research was to develop food processing virtual labs as efficient teaching and study tools for food processing courses using user-friendly computer languages (VC++, MFC and OpenGL). A 3D graphic technique was employed in this study as a specific objective to generate 3D graphics in the visualization mode.According to functionalities, virtual labs were designed for three basic simulations: (1) Calculation simulations, which perform various calculations related to food processing. These simulations help users to remember and understand the formula used in process calculations. Several simple concept calculations were included: conduction heat transfer in steady state through individual and composite slabs; two-component mass balance systems, Pearson rule applications; freezing and thawing time calculations; (2) Animation simulations, which are aimed to visualize processing scenarios for different physical phenomena or working principles. Included in these simulations were: conduction heat transfer through single and multiple walls under steady state; mixing processes involving two and three component systems and Pearson rule concept; freezing and thawing processes through slab, cylinder, and sphere, the three regular shapes, agitation thermal processing modes which include axial agitation and end-over-end agitation in rotational retort; (3) Virtual equipment simulations, which are aimed to dynamically simulate a real operating environment and to demonstrate equipment working principle, internal structure, and operating procedures. The simulated equipment include a horizontal retort used in thermal processing and a high pressure processing equipment used in non-thermal processing.
The food processing virtual labs provide a new way in teaching and learning, with no risk, time or place limitations, and are cost effective. The simulated scenarios and equipment can be used as teaching tools in food processing courses, which provide an efficient way to the instructor/assistant. Instructor/assistant can dynamically and repeatedly demonstrate the operating process for the simulated equipment in a vivid and interested manner. Also students can get intuitive understanding by viewing these simulations. Computers are the waves of the future; however, traditional learning techniques should not be forgotten.*
*This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Windows 95 or higher.
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ROSA, FAENA M. L. "Simulação numérica da migração de elementos metálicos e do monômero e-caprolactama de embalagens poliméricas irradiadas para simulantes de alimentos." reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11653.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP
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Fiorentini, Davide. "Design of a Cartesian Robot for Agro-Food Applications." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Nella tesi si affronta il problema della progettazione di un sistema meccatronico fortemente automatizzato per applicazioni agricole. In particolare il progetto è rivolto alla costruzione di una macchina per l’attività di raccolta automatizzata di teste di broccoli disposte in filari presenti in campo coltivato.
Il fine dello studio, tramite l’applicazione su un vegetale specifico, è l’introduzione di tecnologie di uso ormai comune nel campo industriale in un settore tradizionalmente poco sensibile all’innovazione come quello agricolo. La progettazione deve quindi tenere conto di diverse problematiche di natura differente a quelle tipicamente industriali ed adoperare opportuni accorgimenti.
L’ideazione di un sistema essenzialmente completo e funzionale, con relativa simulazione di un tipico ciclo di lavoro, si presta successivamente ad ulteriori valutazioni non esclusivamente tecniche ma anche di tipo economico.
Dopo un’analisi generale dello scenario, si è trovato idoneo l’utilizzo di un robot cartesiano montato sopra una macchina agricola guidata da un operatore. Viene concretizzato il disegno ed il dimensionamento delle varie componenti meccaniche, compreso il manipolatore.
In seguito è creato un modello matematico del sistema fisico utile a simulare il funzionamento della macchina. Particolare attenzione è data al controllo del robot in quanto risultante essere la parte più critica del sistema. E’ inoltre fornito il controllo temporizzato delle varie azioni.
Infine si è effettuata una simulazione al calcolatore di un tipico ciclo di raccolta su una singola testa broccolo. Il vegetale, riconosciuto dalla macchina, viene raccolto secondo una sequenza di azioni sincronizzate tra loro e depositato in un punto specifico nel raggio di azione del robot. Sono inoltre forniti elementi sugli aspetti simulativi e sull’integrazione tra varie componenti del sistema complesso.
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Rahman, Mohammad Mahbubur. "Microscale modelling of cellular level transport and deformation during food drying." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/120676/1/Mohammad%20Mahbubur_Rahman_Thesis.pdf.
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This thesis contributed to the development of a microscale drying model to predict the actual moisture distribution and physical quality of food material during the drying process. This research has developed a novel methodology to create realistic cellular geometry from microscopic images of food material which can be used as an exact computational domain for the microscale drying model. The model developed is capable of predicting of the cellular level transport and the anisotropic deformation of food material during the drying. The results obtained from the model were validated against extensive experimental investigations.
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Kulasiri, G. Don. "Simulation of deep-bed drying of Virginia peanuts to minimize energy use." Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/39762.
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A deep-bed drying model simulating the drying of peanuts in a fixed bed is required for designing energy-efficient and automatically controlled dryers. A deep-bed drying model consists of a thin-layer drying model to calculate the moisture release from the material and a set of mass and energy balances. An experimental setup was constructed to determine drying rates of Virginia-type peanuts under 14 different drying air conditions. Selected empirical and semi-theoretical models available for modeling thin-layer drying rates were fitted to the collected data using nonlinear regression techniques. The modified Page's model and the two-term exponential model fitted the data better than other models considered. A deep-bed drying model PEATECH based on four coupled partial differential equations consisting of four variables, air temperature, peanut temperature, air humidity, and peanut moisture content was developed. Validation of the model was accomplished by using the data collected from 36 deep-bed drying experiments conducted using three laboratory dryers during 1987, 1988, and 1989. PEATECH predicted the variables within a peanut bed with an accuracy of less than ± 6%. The energy saving potential of exhaust-air recirculation was established by conducting simulated experiments using a modified version of PEATECH.Ph. D.
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Doyle, Carolyn. "Computer modeling and simulation of ground beef and lettuce handling for hamburgers at a typical fast-food restaurant." [Johnson City, Tenn. : East Tennessee State University], 2001. http://etd-submit.etsu.edu/etd/theses/available/etd-1112101-093056/restricted/doylec113001a.pdf.
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Doyle, Carolyn. "Computer Modeling and Simulation of Ground Beef and Lettuce Handling for Hamburgers at a Typical Fast-Food Restaurant." Digital Commons @ East Tennessee State University, 2002. https://dc.etsu.edu/etd/728.
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Numerous Escherichia coli O157:H7 outbreaks have been associated with fast food restaurants. This research created a computer model and simulation with the Micrografx computer software program Process™ for the safe handling of ground beef patties and lettuce in a typical fast food restaurant.
A reference facility was visited to obtain a text description of the flow of food. To create the model, a process diagram was made that graphically represented the series of steps that were taken from the arrival of products to the delivery of the cooked and assembled product to the consumer. A process model was created when the steps in the process diagram was assigned behaviors. The final phase was process simulation.
The simulation results indicated the model was representative of a typical fast-food restaurant. The model was then used successfully to simulate three potential breakdowns of the food safety system that could lead to a foodborne illness outbreak.
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Pietromonaco, Joseph Allen. "A Heat Transfer Model for Industrial Food Processes." Youngstown State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1312936641.
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Kim, Jongsoon. "Dose calculation methodology for irradiation treatment of complex-shaped foods." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1899.
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Ratemo, Assa Isoka. "Maize market liberalisation and food security in Kenya : policy analysis and evaluation using a quadratic programming and simulation approach." Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360738.
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Ahlqvist, Marcus. "Applicability of simulation analysis for planning agri-food supply chains : A case study at a Swedish farmer-owned cooperative." Thesis, Uppsala universitet, Institutionen för samhällsbyggnad och industriell teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-446478.
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Agri-food supply chains (ASCs) are becoming increasingly complex, and its actors are in need of sophisticated planning tools to remain competitive in an industry that have been moving away from small individual actors towards large multi-national, highly vertically integrated cooperatives. This case study views reality from an objectivist point of view and utilises a positivist approach to study this reality. It combines qualitative and quantitative methods to study an ASC operating in the Kingdom of Sweden. This ASC’s planning processes are investigated in order to identify processes that are applicable to simulation by considering model verification, validation, and credibility. The simulation model allowed for system analyses from a strategic perspective and, hence, simplified the planning process of evaluating different scenarios. The model was intrinsically verified and validated in consultation with the supervisor and subject reader and was thus able to accurately imitate the real-world system. The simulated scenarios comprised changes to the ASC’s infrastructure or design. The changes, in turn, comprised decommissions of one or more port-site storage facilities (HPs). Questions that were asked during the evaluation of the experiment results included what happens to the inventory levels of the non-decommissioned HPs when certain ones close? will the demand still be met? and if, then where, will queues arise in the system? It is shown that the non-decommissioned HPs will manage the closed HP’s volumes, but only to a certain extent. One closed HP does not cause severe problems, while two closed ones can create queues, which, in turn, will result in lower than desired inventory levels at the end of the harvesting period. Queues will arise from the closing of just one HP, although this queue is practically negligible, but as two are closed, the queues will create problems. The demand was able to be met even though an HP was closed, but to meet it while two HPs are closed, one of the non-decommissioned ones’ capacity must be increased. This, ultimately, generated or achieved for the host organisation a so called proof of concept (this is argued to generate credibility in the model). Some of the identified characteristics of their ASC are considered generic, while others can only be claimed to be specific the studied ASC. The study thus claims to have initiated a framework for the differentiation of strategic, tactical, and operational planning levels in an ASC.
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Warshamana, Dewayalage Chathura Chandimal Wijerathne. "A new coarse-grained multiscale model for the numerical simulation of morphological changes of food-plant materials during drying." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/130784/1/Chathura%20Chandimal%20Wijerathne_Warshamana%20Dewayalage_Thesis.pdf.
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This research project is a step forward in predicting the bulk-scale deformations in food-plant materials during drying in a computationally efficient and accurate manner. In the proposed numerical modelling method, a novel force interaction field was introduced to represent the mechanics of a whole plant cell during drying through its centroid. By utilising this novel modelling approach, the distinct deformation profiles of several food-plant materials were revealed along with the impact of drying situations and features in the microstructure. The developed modelling framework has potential applications in the field of food engineering in controlling quality attributes of dried food-plant products.
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Crotta, M. "PROBABILISTIC MODELLING IN FOOD SAFETY: A SCIENCE-BASED APPROACH FOR POLICY DECISIONS." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/339138.
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This thesis deals with use of qualitative and quantitative probabilistic models for the animal-derived food safety management. Four unrelated models are presented: three quantitative and one qualitative. Two of the quantitative models concern the risk posed by pathogens in raw milk, in the first study, a probabilistic approach for the inclusion of the variability and the uncertainty in the consumers’ habits and the bacterial pathogenic potential is proposed while the second study, demonstrate how the overlook of the relationship between the storage time and temperature has led to overestimated results in raw milk-related models published so far and an equation to address the issue is provided. In the third study, quantitative modelling techniques are used to simulate the dynamics underlying the spread of Campylobacter in broiler flocks and quantify the potential effects that different on-farm mitigation strategies or management measures have on the microbial load in the intestine of infected birds at the end of the rearing period. In the qualitative study, a general approach for the estimation of the likelihoods of introduction of live parasites in aquaculture implants and the commercialization of infested product is outlined by using the example of Anisakids in farmed Atlantic salmon.
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Jenkinson, William. "Simulation de la mécanique mésoscopique des aliments par méthodes de particules lagrangiennes." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASB047.
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Le rôle des mécanismes mésoscopiques dans le traitement et la conception des aliments est encore mal compris, notamment pour la transformation orale et la perception de la texture. Malgré le développement de la physique de la matière molle, les scientifiques peinent encore à relier les comportements micro-, méso- et macroscopiques par des simulations. Cette thèse se concentre sur les simulations mécaniques, excluant les effets thermiques, chimiques et physico-chimiques, pour explorer le comportement des aliments à l'échelle mésoscopique. Nous avons développé une approche de simulation dans LAMMPS combinant des implémentations de "smoothed-particle hydrodynamics" (SPH) pour les liquides et les solides élastiques. Cette approche a été validée pour des scénarios comme l'écoulement de Couette et la déformation des granules. Les résultats démontrent l'efficacité de l'approche pour capter la dynamique des structures alimentaires et leurs interactions avec des papilles et des cils ; offrant de nouvelles perspectives sur la perception de la texture. L'étude met aussi en évidence l'impact de l'élasticité des granules et de leur fraction volumique sur les propriétés d'écoulement. Ce travail, centré sur la mécanique, reste ouvert à l'intégration future de processus thermiques, chimiques et biologiques dans les modèles alimentaires. Les recherches futures viseront à intégrer plus de physiques et à rendre les outils de simulation plus accessibles aux ingénieurs, pour favoriser les applications pratiques en science des alimentsThe role of mesoscopic mechanics in food processing and design is not well understood, particularly for oral processing and texture perception. Despite the recognized importance of soft matter, the food science community has struggled to bridge the gap between micro-, meso-, and macro-scale behaviours using simulations. This thesis addresses this challenge by focusing on mechanical simulations, excluding thermal, chemical and physicochemical effects, to explore food behaviour at the mesoscopic scale. We have developed a simulation framework within the LAMMPS environment, combining smoothed-particle hydrodynamics (SPH) implementations for liquids and elastic solids. We validated the framework across scenarios such as Couette flow and deformation of granules in a flow. The results show the framework's effectiveness in capturing food structure dynamics and interactions with cilia and papillae and offer new insights into texture perception and hydrodynamics. The study also highlights how granule elasticity and volume fraction impact flow properties and their eventual role in texture perception. This work focuses on mechanics while deliberately remaining flexible enough to integrate mechanical, thermal, chemical, and biological processes in future food science models. Proposed future research includes strategies to integrate more physics and scales and efforts to improve the accessibility of simulation tools for engineers, advancing practical applications in food science
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Sawert, Adam. "Dynamic Menu Management Utilizing the Relationship Between Preparation Time and Monetary Revenue : A Simulation Approach to the Food and Beverage Industry." Thesis, Luleå tekniska universitet, Datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-80925.
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Queue buildup is a problem that every fast food restaurant would like to reduce, as its effect on customer satisfaction and restaurant revenue is obviously negative. This thesis looks at how a dynamic menu management system would affect fast food restaurants, specifically how the promotion of fast products, in certain situations, would affect total revenue and queue lengths. A neural network was used to categorize products depending on their preparation time and to predict queue waiting times. A simulation approach was used to find out how the menu management system would affect the restaurant. The results are that in situations where long queues are formed, the promotion of fast products increases revenue by 7.8% and decreases queue lengths by 13.3%. In situations where little to no queues are formed, the same system still decreases queue lengths by 4.7%, but also decreases revenue by 0.2%
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Dallinger, Niels, and Jörg Hübler. "Simulation of Bottle Conveyors – Opportunities of the Discrete Element Method (DEM)." Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-231768.
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The Discrete Element Method (DEM) provides an approach to recognition of the problems within bottle conveyors at an early stage of the engineering process. Key points in bottle conveyor systems, such as buffers, ejectors, diverters and transfers can be numerically analyzed. It is possible to calculate forces on lateral guides and forces between bottles within accumulation situations. The DEM provides an alternative opportunity for the virtual process optimization and numeric case studies of conveying systems at beverage and food industriesDie diskrete Elementmethode (DEM) ermöglicht in einem frühen Stadium des Engineering-Prozesses die Erkennung von Problemen in Flaschenförderern. Wichtige Systemelemente wie Puffer, Ausschleuser, Weichen und Übergabestellen können numerisch analysiert werden. Es ist somit u. a. möglich, Kräfte auf Seitenführungen und Kräfte zwischen den Flaschen innerhalb von Stausituationen zu berechnen. Die DEM bietet eine alternative Möglichkeit für die virtuelle Prozessoptimierung und die Durchführung numerischer Fallstudien von Fördersystemen u. a. in der Getränke- und Lebensmittelindustrie
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Culbertson, Greg S. "Investigating methods of conditioning fresh vegetables in retail establishments and exploring procedural modifications that improve product quality and safety." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397488227.
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Forsell, Adam. "Exploring the Efficiency of a Digital Simulation Game for Vocational Training : An experimental approach." Thesis, Högskolan i Skövde, Institutionen för informationsteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-16526.
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This thesis covers an experiment which explores how effectively skills that are gained in a digital serious game can be transferred to a real situation. The context of the experiment is the casual restaurant industry, with focus on the task of a food runner. The results showed to be unreliable when ruling out the chance element with the use of t-tests, which points to that the data produced were coincidental, however the limited deviation in the groups’ performances indicate that there is potential in the addition of a digital game to the traditional training material. This is learned from the reports of the experiments and the analysis of the questionnaires filled out by all the participators.
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Fageehi, Yahya. "SIMULATION-BASED OPTIMIZATION FOR COMPLEX SYSTEMS WITH SUPPLY AND DEMAND UNCERTAINTY." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1531147903589262.
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Shirmohammadi, Maryam. "Process modelling and simulation of tissue damage during mechanical peeling of pumpkin as a tough skinned vegetable." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/67921/1/Maryam_Shirmohammadi_Thesis.pdf.
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Food waste is a current challenge that both developing and developed countries face. This project applied a novel combination of available methods in Mechanical, agricultural and food engineering to address these challenges. A systematic approach was devised to investigate possibilities of reducing food waste and increasing the efficiency of industry by applying engineering concepts and theories including experimental, mathematical and computational modelling methods. This study highlights the impact of comprehensive understanding of agricultural and food material response to the mechanical operations and its direct relation to the volume of food wasted globally.
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Garedew, Efrem. "Land-use and land-cover dynamics and rural livelihood perspectives, in the semi-arid areas of Central Rift Valley of Ethiopia." Umeå : Dept.of Forest Resource Management, Swedish University of Agricultural Sciences, 2010. http://epsilon.slu.se/201007.pdf.
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D'AMMARO, DANIELE. "From environmental concerns toward sustainable agro-food production. Mathematical models, indicators to achieve the sustainability of the wine sector." Doctoral thesis, Università Cattolica del Sacro Cuore, 2022. http://hdl.handle.net/10280/115286.
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Il sistema alimentare è sempre più interconnesso con il nostro futuro, il quale include un'ampia varietà di preoccupazioni della società che vanno dalla sicurezza alimentare, alla nutrizione, alle disuguaglianze sociali ed economiche, al cambiamento climatico, alla biodiversità e ai servizi generati dagli ecosistemi oceanici. In particolare, la filiera agroalimentare del vino emerge come una tra le filiere più analizzate data la sua importante rilevanza nel mercato economico produttivo e distributivo mondiale. In accordo con le disposizioni del New Green Deal dell'Unione Europea e dell'Agenda 2030 delle Nazioni Unite, il settore vitivinicolo deve indirizzarsi verso sistemi di gestione economicamente e ambientalmente sostenibili, legati a produzioni di qualità e ad un contesto riconosciuto e remunerato di conservazione della biodiversità. Una corretta scelta dei metodi e delle linee di azione per migliorare la sostenibilità del settore vitivinicolo deve iniziare con un'analisi obiettiva e accurata delle prestazioni di sostenibilità dei suoi prodotti e delle procedure. In questo contesto, la presente tesi mira a una più profonda comprensione delle strategie applicate nel settore vitivinicolo e dei loro risultati. A tal fine, sono state condotte numerose valutazioni, con diversi indicatori impiegati per misurare, monitorare e migliare le prestazioni di sostenibilità.The food system is increasingly interlinked with our future, which includes a wide variety of societal concerns ranging from food security, nutrition, social and economic inequities to climate change, biodiversity, and ocean ecosystem services. In particular, the wine chain emerges as one of the most examined areas given its significant relevance in economic production and global distribution market. In accordance with the provisions of the European Union's New Green Deal and the United Nations Agenda 2030, the wine sector must strive to transition to economically and environmentally sustainable management systems, linked to premium quality production and a recognized and remunerated context of biodiversity conservation. A proper determination of the methods and courses of action to enhance the wine industry's sustainability must begin with an objective and accurate analysis of its products and procedures' sustainability performance. Within this framework, the present thesis aims at a deeper understanding of the strategies applied in the wine sector and of their outcomes. For this purpose, numerous assessments have been conducted, with different indicators used to measure, monitor and improve sustainability performance.
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Nascimento, Nayra Reis do. "Análise termodinâmica e otimização de um sistema de refrigeração por absorção para conservação de alimentos." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266783.
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Orientadores: José Vicente Hallak d'Angelo, Francine de Mendonça FábregaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Sistemas de refrigeração têm diversas aplicações, como por exemplo: proporcionar conforto térmico através da climatização de ambientes; gerar utilidades frias para aplicações em processos industriais; conservação de alimentos, bebidas e produtos farmacêuticos, entre outros. Sistemas de refrigeração por absorção podem ser aplicados para obter níveis de refrigeração menor, utilizando fontes alternativas de energia, como por exemplo, a energia solar. Essa tecnologia pode ser implantada em regiões onde não há energia elétrica, como é o caso de boa parte do Estado do Amazonas. No entanto, nessa região, há um alto potencial de energia solar, pois é cortada pela Linha do Equador. Nesse trabalho, um ciclo de refrigeração por absorção capaz de ser acionado por energia solar, utilizando como fluidos refrigerante-absorvente NH3/H2O, R134a/DMF, (R134a+R32+R23)/DMF e (R134a+R32)/DMF, foi estudado visando sua aplicação para a conservação de alimentos de pequenas comunidades do Estado do Amazonas. Os ciclos foram simulados utilizando o simulador de processos Aspen Hysys®, versão 7.2. Uma vez validadas as simulações, foi realizada uma análise termodinâmica das principais variáveis operacionais (temperatura do gerador e do evaporador e pressão da região de baixa pressão) e em seguida, utilizando a ferramenta Optimizer do simulador, foi realizada a otimização dos ciclos visando a maximização do coeficiente de desempenho (COP) dos mesmos, obtendo-se uma melhoria em torno de 8 % para o sistema NH3/H2O. Para o sistema R134a/DMF, O COP aumentou 25 %. Os sistemas simulados mostraram-se adequados para usar como fonte de calor no gerador, a energia solar, aproveitando assim a alta incidência que ocorre no local proposto para sua aplicação
Abstract: Refrigeration systems have a lot of applications, like: thermal comfort for environmental acclimatization; generation of cold utilities used in industrial processes; food, beverage and pharmaceutical products preservation, and many others. Absorption refrigeration systems may be used to obtain refrigeration at low levels, using energy alternative sources, as solar energy for example. This technology may be implemented in places where there is no electric energy available, like is the case of a great part of Amazonas State. In this region, there is a high availability of solar energy, since it is situated at Equator Line. In this work, absorption refrigeration cycles, which can use solar energy as primary energy source, using the following pairs refrigerant-absorbent NH3/H2O, R134a/DMF, (R134a+R32+R23)/DMF e (R134a+R32)/DMF were studied, aiming its application for food preservation in small communities at Amazonas State. The cycles were simulated using a commercial process simulator, Aspen Hysys®, version 7.2. Once the simulations performed were validated using literature data, a thermodynamic analysis of the main operational variables of the cycle was done. These variables are: generator and evaporator outlet temperature and pressure at low pressure side of the cycle and then, using the Optimizer tool of the simulator, the optimization of the cycle was performed using as objective function the maximization of the coefficient of performance (COP). An improvement of 8% for the system NH3/H2O was achieved. For the system R134a/DMF, an increase of 25% for the COP was observed. Simulated systems are adequate to use solar energy as heat source in the generator, using the great potential of the region proposed for their application
Mestrado
Sistemas de Processos Quimicos e Informatica
Mestre em Engenharia Química
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Roockley, Claire Ellen. "A Mixed Methods Obesity Prevention Intervention For Australian Children Aged 6-12 Years: Influence Of Parents Misperceptions About Food And Exercise On The Efficacy Of Educational Obesity Simulations." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2014. https://ro.ecu.edu.au/theses/1419.
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Increasing numbers of Australian children are being classified as overweight or obese. Given the health complications associated with excess weight, interventions to prevent children becoming overweight are crucial. Despite literature showing that parents shape their children’s food and exercise habits, no child obesity prevention programs have directly targeted parents. Moreover, although fear appeals have been used across several health promotion areas to change attitudes and behaviours, they have not been incorporated into an obesity preventive program. This study addressed these gaps by testing whether fear-based obesity simulations, targeted at parents as a tool for preventing childhood obesity, was more effective than an educational obesity message. The study was designed in two stages, with the first piloting the effectiveness of the simulations and an obesity message on a small sample of parents. Stage 2 tested a larger sample of parents and incorporated modifications from the pilot. In Stage 1, nine parents were randomly assigned to a Simulation or Education Presentation. Parents completed interviews and questionnaires at three different time points over a week. SPANOVAs revealed no significant improvements in attitudes, intentions, motivations, fears, and knowledge about obesity prevention for the Simulation compared to the Education Presentation. This contrasted to interview findings which indicated that parents found the Simulation Presentation more effective and changed their attitudes and behaviours compared to the Education Presentation. These findings highlighted important outcomes and informed the development of Stage 2. A qualitative approach was more effective in eliciting parental responses to their presentation; the education information may have been “too effective” and masked any impact of the simulations; and potential limitations regarding the insensitivity of the Likert scale, used to measure changes in parent responses to the questionnaire, may have mitigated any significant effects being found. The purpose of Stage 2 was to explore any impact of the simulations only through in depth parent interviews, and to use objective pedometer, food and anthropometric measures to triangulate and enhance the interview findings. Twenty four different parents were assigned to a photo or non-photo group. Parents and children completed interviews, anthropometric measurements, food records, and pedometer counts at three time points over eight weeks. Quantitative analyses found no significant improvements in children’s pedometer scores, food intake, and achievement of activity and diet recommendations, or in parent intention to change their children’s eating and exercise habits for the photo compared to the non-photo group. Many children failed to meet daily food and activity guidelines by the end of the study. This contrasts markedly to interview findings stating that: parents made improvements to their children’s diet and exercise patterns and, for parents who didn’t make changes, this was attributed to perceptions that they were already doing the right thing for their children. This disparity in results revealed an important yet underexplored issue for interventions targeting weight-related lifestyle changes. This focuses on levels of parental awareness about their children’s dietary adequacy and activity levels, and bridging the gap between what one perceives they are doing versus the reality of what is actually happening. This discrepancy may have mitigated any impact of the simulations through a false sense of adequacy and parent risk levels toward their children developing obesity.
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Gianfrancesco, Alessandro. "Séchage par atomisation : propriétés de collage des particules en relation avec l'agglomération." Phd thesis, AgroParisTech, 2009. http://pastel.archives-ouvertes.fr/pastel-00005602.
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Les poudres alimentaires instantanées (lait, soupe, jus, café) sont habituellement produites par séchage par pulvérisation, suivi d'une étape ultérieure d'agglomération pour augmenter la taille des particules (de 50-100 μm à 250-500 μm) avec une distribution de taille étroite et une structure modifiée (porosité), pour améliorer la manutention et les propriétés instantanées (mouillabilité, dispersibilité, solubilité). L'agglomération est réalisée dans un lit fluidisé intérieur ou extérieur à la chambre de séchage, ou par réinsertion des fines (sèches) dans la chambre. L'agglomération de particules passe par les contacts et l'adhésion entre particules pour créer des liaisons entre elles. Les propriétés collantes de la surface d'une particule dépendent de la présence de constituants capables de développer un comportement collant. Pour les polysaccharides le collage est lié à la transition vitreuse, en relation avec la teneur en eau, l'activité de l'eau et la température, paramètres représentatifs du séchage. Une méthode est développée pour relier l'évolution des propriétés de l'air de séchage au séchage des particules dans la chambre. Les mesures de la température de l'air et de son humidité relative ont permis de calculer l'évolution de la teneur en eau des gouttes dans la chambre, et d'en déduire des conditions opératoires et positions où les particules seraient collantes. Des solutions aqueuses de produits modèles (collants) (maltodextrine DE12 et DE21) ont été séchées dans un séchoir pilote en co-courant, avec turbine de pulvérisation. L'effet de différents paramètres ont été étudiés : le débit liquide (1 à 3,2 kg.h-1 d'eau évaporée), la température d'entrée de l'air (144 à 200°C), le débit d'air (80 - 110 kg. h-1) et la vitesse de rotation de la turbine (22500 à 30000 rpm). Les particules de maltodextrine DE12 sont rapidement séchées en dessous de la température de transition vitreuse, et le collage est envisagé seulement près de l'atomiseur. La maltodextrine DE21 montre un comportement collant dans une large partie de la chambre, dû à de plus faibles températures de transition vitreuse, en particulier pour des forts débits de liquide et des faibles températures de l'air de séchage. La mécanique des fluides numérique (CFD) est aussi utilisée pour simuler le séchage de solutions, et pour prédire l'existence de conditions collantes. Ces conditions ont été testées et validées par des essais d'agglomération réalisés en introduisant de la poudre à différents endroits dans la chambre. Enfin, cette approche expérimentale basée sur la mesure des propriétés de l'air a été appliquée pour interpréter le comportement au séchage d'un produit différent (hydrolysat de protéines) dans un séchoir pilote à plus grande échelle, équipé d'un retour de fines et d'un lit fluidisé interne.
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Anputhas, Markandu. "Simulating land use change for assessing future dynamics of land and water resources." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/56181.
Full textAbstract:
Models of land use change fall into two broad categories: pattern based and process based. This thesis focuses on pattern based land use change models, expanding our understanding of these models in three important ways.
First, it is demonstrated that some driving variables do not have a smooth impact on the land use transition process. Our example variable is access to water. Land managers with access to piped water do not have any need for surface or groundwater. For variables like this, a model needs to change the way that driving variables are represented. The second important result is that including a variable which captures spatial correlation between land use types significantly increases the explanatory power of the prediction model. A major weakness of pattern based land use models is their inability to model interactions between neighbouring land parcels; the method proposed in this study can be an alternative to account for spatial neighbourhood association.
These innovations are applied using the CLUE-S (Conversion of Land Use and its Effects at Small regional extent) system to the Deep Creek watershed in the Southern Interior of British Columbia. The results highlight the challenge of balancing the protection of agricultural land and conserving forest and natural areas when population and economic growth are inevitable. The results also demonstrate the implications of land use change on existing land use policies.
The calibrated model was validated using remote sensing data. A series of discriminant functions were estimated for each land use type in the recent period and these functions were then used to classify. The calibrated model was run in reverse, back to the generated land use classification, and results compared. Fit was reasonable with error rates falling below ten percent when radii beyond 2.5 km were considered.
Another important contribution is demonstrating the importance of modelling dynamic variables. Some important drivers are changing continuously and others depend on land use change itself. Failure to update these variables will bias model forecasts. Spatial neighbourhood association, an endogenous variable governed by land use change itself, is again used as the example dynamic variable. The study demonstrates the importance of updating all associated information.Graduate Studies, College of (Okanagan)
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