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Sample records for aspen economic model

  1. Full employment and competition in the Aspen economic model: implications for modeling acts of terrorism.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Ehlen, Mark Andrew

    2004-11-01

    Acts of terrorism could have a range of broad impacts on an economy, including changes in consumer (or demand) confidence and the ability of productive sectors to respond to changes. As a first step toward a model of terrorism-based impacts, we develop here a model of production and employment that characterizes dynamics in ways useful toward understanding how terrorism-based shocks could propagate through the economy; subsequent models will introduce the role of savings and investment into the economy. We use Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate for validation purposes that a single-firm economy converges to the known monopoly equilibrium price, output, and employment levels, while multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment. However, we find that competition also leads to churn by consumers seeking lower prices, making it difficult for firms to optimize with respect to wages, prices, and employment levels. Thus, competitive firms generate market ''noise'' in the steady state as they search for prices and employment levels that will maximize profits. In the context of this model, not only could terrorism depress overall consumer confidence and economic activity but terrorist acts could also cause normal short-run dynamics to be misinterpreted by consumers as a faltering economy.

  2. Aspen: A microsimulation model of the economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.; Quint, T.; Arnold, T.

    1996-10-01

    This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of the model are also presented.

  3. Refuse Derived Fuel (RDF) production and gasification in a pilot plant integrated with an Otto cycle ICE through Aspen plus™ modelling: Thermodynamic and economic viability.

    Science.gov (United States)

    Násner, Albany Milena Lozano; Lora, Electo Eduardo Silva; Palacio, José Carlos Escobar; Rocha, Mateus Henrique; Restrepo, Julian Camilo; Venturini, Osvaldo José; Ratner, Albert

    2017-11-01

    This work deals with the development of a Refuse Derived Fuel (RDF) gasification pilot plant using air as a gasification agent. A downdraft fixed bed reactor is integrated with an Otto cycle Internal Combustion Engine (ICE). Modelling was carried out using the Aspen Plus™ software to predict the ideal operational conditions for maximum efficiency. Thermodynamics package used in the simulation comprised the Non-Random Two-Liquid (NRTL) model and the Hayden-O'Connell (HOC) equation of state. As expected, the results indicated that the Equivalence Ratio (ER) has a direct influence over the gasification temperature and the composition of the Raw Produced Gas (RPG), and effects of ER over the Lower Heating Value (LHV) and Cold Gasification Efficiency (CGE) of the RPG are also discussed. A maximum CGE efficiency of 57-60% was reached for ER values between 0.25 and 0.3, also an average reactor temperature values in the range of 680-700°C, with a peak LHV of 5.8MJ/Nm 3 . RPG was burned in an ICE, reaching an electrical power of 50kW el . The economic assessment of the pilot plant implementation was also performed, showing the project is feasible, with power above 120kW el with an initial investment of approximately US$ 300,000. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Landscape composition in aspen woodlands under various modeled fire regimes

    Science.gov (United States)

    Eva K. Strand; Stephen C. Bunting; Lee A. Vierling

    2012-01-01

    Quaking aspen (Populus tremuloides) is declining across the western United States. Aspen habitats are diverse plant communities in this region and loss of these habitats can cause shifts in biodiversity, productivity, and hydrology across spatial scales. Western aspen occurs on the majority of sites seral to conifer species, and long-term maintenance of these aspen...

  5. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    International Nuclear Information System (INIS)

    Joshi, D.M.; Patel, H.K.

    2015-01-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant

  6. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  7. Modeling hygroelastic properties of genetically modified aspen

    Science.gov (United States)

    Laszlo Horvath; Perry Peralta; Ilona Peszlen; Levente Csoka; Balazs Horvath; Joseph Jakes

    2012-01-01

    Numerical and three-dimensional finite element models were developed to improve understanding of major factors affecting hygroelastic wood properties. Effects of chemical composition, microfibril angle, crystallinity, structure of microfibrils, moisture content, and hydrophilicity of the cell wall were included in the model. Wood from wild-type and decreased-lignin...

  8. Model-based assessment of aspen responses to elk herbivory in Rocky Mountain National Park

    Science.gov (United States)

    Peter J. Weisberg; Michael B. Coughenour

    2001-01-01

    In Rocky Mountain National Park, aspen has been observed to decline on elk winter range for many decades. The SAVANNA ecosystem model was adapted to explore interactions between elk herbivory and aspen dynamics on the elk winter range. Several scenarios were explored that considered different levels of overall elk population; different levels of elk utilization of...

  9. Physical property parameter set for modeling ICPP aqueous wastes with ASPEN electrolyte NRTL model

    International Nuclear Information System (INIS)

    Schindler, R.E.

    1996-09-01

    The aqueous waste evaporators at the Idaho Chemical Processing Plant (ICPP) are being modeled using ASPEN software. The ASPEN software calculates chemical and vapor-liquid equilibria with activity coefficients calculated using the electrolyte Non-Random Two Liquid (NRTL) model for local excess Gibbs free energies of interactions between ions and molecules in solution. The use of the electrolyte NRTL model requires the determination of empirical parameters for the excess Gibbs free energies of the interactions between species in solution. This report covers the development of a set parameters, from literature data, for the use of the electrolyte NRTL model with the major solutes in the ICPP aqueous wastes

  10. Simulation of a tubular solid oxide fuel cell stack using AspenPlusTM unit operation models

    International Nuclear Information System (INIS)

    Zhang, W.; Croiset, E.; Douglas, P.L.; Fowler, M.W.; Entchev, E.

    2005-01-01

    The design of a fuel cell system involves both optimization of the fuel cell stack and the balance of plant with respect to efficiency and economics. Many commercially available process simulators, such as AspenPlus TM , can facilitate the analysis of a solid oxide fuel cell (SOFC) system. A SOFC system may include fuel pre-processors, heat exchangers, turbines, bottoming cycles, etc., all of which can be very effectively modelled in process simulation software. The current challenge is that AspenPlus TM or any other commercial process simulators do not have a model of a basic SOFC stack. Therefore, to enable performing SOFC system simulation using one of these simulators, one must construct an SOFC stack model that can be implemented in them. The most common approach is to develop a complete SOFC model in a programming language, such as Fortran, Visual Basic or C++, first and then link it to a commercial process simulator as a user defined model or subroutine. This paper introduces a different approach to the development of a SOFC model by utilizing existing AspenPlus TM functions and existing unit operation modules. The developed ''AspenPlus TM SOFC'' model is able to provide detailed thermodynamic and parametric analyses of the SOFC operation and can easily be extended to study the entire power plant consisting of the SOFC and the balance of plant without the requirement for linking with other software. Validation of this model is performed by comparison to a Siemens-Westinghouse 100 kW class tubular SOFC stack. Sensitivity analyses of major operating parameters, such as utilization factor (U f ), current density (I c ) and steam-carbon ratio (S/C), were performed using the developed model, and the results are discussed in this paper

  11. Simulation Model of Membrane Gas Separator Using Aspen Custom Modeler

    Energy Technology Data Exchange (ETDEWEB)

    Song, Dong-keun [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Shin, Gahui; Yun, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-12-15

    Membranes are used to separate pure gas from gas mixtures. In this study, three different types of mass transport through a membrane were developed in order to investigate the gas separation capabilities of a membrane. The three different models typically used are a lumped model, a multi-cell model, and a discretization model. Despite the multi-cell model producing similar results to a discretization model, the discretization model was selected for this investigation, due to the cell number dependence of a multi-cell model. The mass transport model was then used to investigate the effects of pressure difference, flow rate, total exposed area, and permeability. The results showed that the pressure difference increased with the stage cut, but the selectivity was a trade-off for the increasing pressure difference. Additionally, even though permeability is an important parameter, the selectivity and stage cut of the membrane converged as permeability increased.

  12. Aspen Delineation - Aspen Delineation Project [ds362

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands, where aspen assessment data was gathered. Aspen assessment information corresponding to this polygon layer can...

  13. Pyrolysis of waste tires: A modeling and parameter estimation study using Aspen Plus®.

    Science.gov (United States)

    Ismail, Hamza Y; Abbas, Ali; Azizi, Fouad; Zeaiter, Joseph

    2017-02-01

    This paper presents a simulation flowsheet model of a waste tire pyrolysis process with feed capacity of 150kg/h. A kinetic rate-based reaction model is formulated in a form implementable in the simulation package Aspen Plus, giving the flowsheet model the capability to predict more than 110 tire pyrolysis products as reported in experiments by Laresgoiti et al. (2004) and Williams (2013) for the oil and gas products respectively. The simulation model is successfully validated in two stages: firstly against experimental data from Olazar et al. (2008) by comparing the mass fractions for the oil products (gas, liquids (non-aromatics), aromatics, and tar) at temperatures of 425, 500, 550 and 610°C, and secondly against experimental results of main hydrocarbon products (C 7 to C 15 ) obtained by Laresgoiti et al. (2004) at temperatures of 400, 500, 600, and 700°C. The model was then used to analyze the effect of pyrolysis process temperature and showed that increased temperatures led to chain fractions from C 10 and higher to decrease while smaller chains increased; this is attributed to the extensive cracking of the larger hydrocarbon chains at higher temperatures. The utility of the flowsheet model was highlighted through an energy analysis that targeted power efficiency of the process determined through production profiles of gasoline and diesel at various temperatures. This shows, through the summation of the net power gain from the plant for gasoline plus diesel that the maximum net power lies at the lower temperatures corresponding to minimum production of gasoline and maximum production of diesel. This simulation model can thus serve as a robust tool to respond to market conditions that dictate fuel demand and prices while at the same time identifying optimum process conditions (e.g. temperature) driven by process economics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Modeling Carbon Dioxide Capture by Monoethanolamine Solvent with ASPEN Plus

    Science.gov (United States)

    Luo, Tianyi

    Fossil fuels provide approximately 80% of the world's energy demands. Methods for reducing CO2 emissions resulting from fossil fuels include increasing the efficiency of power plants and production processes, decreasing energy demands, in combination with CO2 capture and long term storage (CCS). CO2 capture technologies include post-combustion, pre-combustion, and oxyfuel combustion. The amine-based post-combustion CO2 capture from a coal-fired power plant was studied in this thesis. In case of post-combustion capture, CO2 can be captured by Monoethanolamine solvent (MEA), a primary ethanolamine. MEA can associate with H3O+ to form an ion MEAH+, and can react with CO2 to form a carbonate ion MEACOO-. Commercial code ASPEN Plus was used to simulate the process of CO2 capture and optimize the process parameters and required energy duty. The major part of thermal energy requirement is from the Absorber and Stripper columns. This suggests that process optimization should focus on the Absorption/Desorption process. Optimization results show that the gas-liquid reaction equilibrium is affected by several operating parameters including solvent flow rate, stream temperature, column operating pressure, flue gas composition, solvent concentration and absorber design. With optimized CO2 capture, the energy consumption for solvent regeneration (reboiler thermal duty) was decreased from 5.76 GJ/ton captured CO2 to 4.56 GJ/t CO2. On the other hand, the cost of CO2 capture (and sequestration) could be reduced by limiting size of the Absorber column and operating pressure.

  15. ASPEN: A fully kinetic, reduced-description particle-in-cell model for simulating parametric instabilities

    International Nuclear Information System (INIS)

    Vu, H.X.; Bezzerides, B.; DuBois, D.F.

    1999-01-01

    A fully kinetic, reduced-description particle-in-cell (RPIC) model is presented in which deviations from quasineutrality, electron and ion kinetic effects, and nonlinear interactions between low-frequency and high-frequency parametric instabilities are modeled correctly. The model is based on a reduced description where the electromagnetic field is represented by three separate temporal envelopes in order to model parametric instabilities with low-frequency and high-frequency daughter waves. Because temporal envelope approximations are invoked, the simulation can be performed on the electron time scale instead of the time scale of the light waves. The electrons and ions are represented by discrete finite-size particles, permitting electron and ion kinetic effects to be modeled properly. The Poisson equation is utilized to ensure that space-charge effects are included. The RPIC model is fully three dimensional and has been implemented in two dimensions on the Accelerated Strategic Computing Initiative (ASCI) parallel computer at Los Alamos National Laboratory, and the resulting simulation code has been named ASPEN. The authors believe this code is the first particle-in-cell code capable of simulating the interaction between low-frequency and high-frequency parametric instabilities in multiple dimensions. Test simulations of stimulated Raman scattering, stimulated Brillouin scattering, and Langmuir decay instability are presented

  16. Comparative simulation study of gas-phase propylene polymerization in fluidized bed reactors using aspen polymers and two phase models

    Directory of Open Access Journals (Sweden)

    Shamiria Ahmad

    2013-01-01

    Full Text Available A comparative study describing gas-phase propylene polymerization in fluidized-bed reactors using Ziegler-Natta catalyst is presented. The reactor behavior was explained using a two-phase model (which is based on principles of fluidization as well as simulation using the Aspen Polymers process simulator. The two-phase reactor model accounts for the emulsion and bubble phases which contain different portions of catalysts with the polymerization occurring in both phases. Both models predict production rate, molecular weight, polydispersity index (PDI and melt flow index (MFI of the polymer. We used both models to investigate the effect of important polymerization parameters, namely catalyst feed rate and hydrogen concentration, on the product polypropylene properties, such as production rate, molecular weight, PDI and MFI. Both the two-phase model and Aspen Polymers simulator showed good agreement in terms of production rate. However, the models differed in their predictions for weight-average molecular weight, PDI and MFI. Based on these results, we propose incorporating the missing hydrodynamic effects into Aspen Polymers to provide a more realistic understanding of the phenomena encountered in fluidized bed reactors for polyolefin production.

  17. Thermochemical Equilibrium Model of Synthetic Natural Gas Production from Coal Gasification Using Aspen Plus

    Directory of Open Access Journals (Sweden)

    Rolando Barrera

    2014-01-01

    Full Text Available The production of synthetic or substitute natural gas (SNG from coal is a process of interest in Colombia where the reserves-to-production ratio (R/P for natural gas is expected to be between 7 and 10 years, while the R/P for coal is forecasted to be around 90 years. In this work, the process to produce SNG by means of coal-entrained flow gasifiers is modeled under thermochemical equilibrium with the Gibbs free energy approach. The model was developed using a complete and comprehensive Aspen Plus model. Two typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated. Emphasis is put on interactions between the fuel feeding technology and selected energy output parameters of coal-SNG process, that is, energy efficiencies, power, and SNG quality. It was found that coal rank does not significantly affect energy indicators such as cold gas, process, and global efficiencies. However, feeding technology clearly has an effect on the process due to the gasifying agent. Simulations results are compared against available technical data with good accuracy. Thus, the proposed model is considered as a versatile and useful computational tool to study and optimize the coal to SNG process.

  18. A kinetic reaction model for biomass pyrolysis processes in Aspen Plus

    International Nuclear Information System (INIS)

    Peters, Jens F.; Banks, Scott W.; Bridgwater, Anthony V.; Dufour, Javier

    2017-01-01

    Highlights: • Predictive kinetic reaction model applicable to any lignocellulosic feedstock. • Calculates pyrolysis yields and product composition as function of reactor conditions. • Detailed modelling of product composition (33 model compounds for the bio-oil). • Good agreement with literature regarding yield curves and product composition. • Successful validation with pyrolysis experiments in bench scale fast pyrolysis rig. - Abstract: This paper presents a novel kinetic reaction model for biomass pyrolysis processes. The model is based on the three main building blocks of lignocellulosic biomass, cellulose, hemicellulose and lignin and can be readily implemented in Aspen Plus and easily adapted to other process simulation software packages. It uses a set of 149 individual reactions that represent the volatilization, decomposition and recomposition processes of biomass pyrolysis. A linear regression algorithm accounts for the secondary pyrolysis reactions, thus allowing the calculation of slow and intermediate pyrolysis reactions. The bio-oil is modelled with a high level of detail, using up to 33 model compounds, which allows for a comprehensive estimation of the properties of the bio-oil and the prediction of further upgrading reactions. After showing good agreement with existing literature data, our own pyrolysis experiments are reported for validating the reaction model. A beech wood feedstock is subjected to pyrolysis under well-defined conditions at different temperatures and the product yields and compositions are determined. Reproducing the experimental pyrolysis runs with the simulation model, a high coincidence is found for the obtained fraction yields (bio-oil, char and gas), for the water content and for the elemental composition of the pyrolysis products. The kinetic reaction model is found to be suited for predicting pyrolysis yields and product composition for any lignocellulosic biomass feedstock under typical pyrolysis conditions

  19. A new numerical approach for a detailed multicomponent gas separation membrane model and AspenPlus simulation

    Energy Technology Data Exchange (ETDEWEB)

    Murad Chowdhury, M.H.; Feng, X.; Douglas, P.; Croiset, E. [Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2005-07-01

    A new numerical solution approach for a widely accepted model developed earlier by Pan [1] for multicomponent gas separation by high-flux asymmetric membranes is presented. The advantage of the new technique is that it can easily be incorporated into commercial process simulators such as AspenPlus trademark [2] as a user-model for an overall membrane process study and for the design and simulation of hybrid processes (i.e., membrane plus chemical absorption or membrane plus physical absorption). The proposed technique does not require initial estimates of the pressure, flow and concentration profiles inside the fiber as does in Pan's original approach, thus allowing faster execution of the model equations. The numerical solution was formulated as an initial value problem (IVP). Either Adams-Moulton's or Gear's backward differentiation formulas (BDF) method was used for solving the non-linear differential equations, and a modified Powell hybrid algorithm with a finite-difference approximation of the Jacobian was used to solve the non-linear algebraic equations. The model predictions were validated with experimental data reported in the literature for different types of membrane gas separation systems with or without purge streams. The robustness of the new numerical technique was also tested by simulating the stiff type of problems such as air dehydration. This demonstrates the potential of the new solution technique to handle different membrane systems conveniently. As an illustration, a multi-stage membrane plant with recycle and purge streams has been designed and simulated for CO{sub 2} capture from a 500 MW power plant flue gas as a first step to build hybrid processes and also to make an economic comparison among different existing separation technologies available for CO{sub 2} separation from flue gas. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  20. Aspen Characteristics - Aspen Delineation Project [ds361

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Lake Tahoe Basin Management Unit (Placer and...

  1. Development of Aspen: A microanalytic simulation model of the US economy

    Energy Technology Data Exchange (ETDEWEB)

    Pryor, R.J.; Basu, N.; Quint, T.

    1996-02-01

    This report describes the development of an agent-based microanalytic simulation model of the US economy. The microsimulation model capitalizes on recent technological advances in evolutionary learning and parallel computing. Results are reported for a test problem that was run using the model. The test results demonstrate the model`s ability to predict business-like cycles in an economy where prices and inventories are allowed to vary. Since most economic forecasting models have difficulty predicting any kind of cyclic behavior. These results show the potential of microanalytic simulation models to improve economic policy analysis and to provide new insights into underlying economic principles. Work already has begun on a more detailed model.

  2. Minnesota's Aspen Resource

    Science.gov (United States)

    Pamela J. Jakes

    1981-01-01

    The fourth Minnesota Forest Inventory shows that aspen continues to dominate the State's forests. Thirty-nine percent of Minnesota's commercial forest area is in the aspen forest type. Aspen species accounted for the largest portion of growing-stock inventory, net annual growth, and removals.

  3. Fire regimes of quaking aspen in the Mountain West

    Science.gov (United States)

    Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

    2013-01-01

    settings and correlated aspen functional types. We propose the following aspen fire regime types: (1) fire-independent, stable aspen; (2) fire-influenced, stable aspen; (3) fire-dependent, seral, conifer-aspen mix; (4) fire-dependent, seral, montane aspen-conifer; and (5) fire-dependent, seral, subalpine aspen-conifer. Closing research gaps and validating our proposed aspen fire regime classification will likely require additional site-specific research, enhanced dendrochronology techniques, charcoal and pollen record analysis, spatially-explicit modeling, and other techniques. We hope to encourage development of site-appropriate disturbance ecology characterizations, in order to aid efforts to manage and restore aspen communities and to diagnose key factors contributing to changes in aspen.

  4. Modelling and testing the performance of a commercial ammonia/water absorption chiller using Aspen-Plus platform

    International Nuclear Information System (INIS)

    Mansouri, Rami; Boukholda, Ismail; Bourouis, Mahmoud; Bellagi, Ahmed

    2015-01-01

    A steady-state simulation model of a commercial 3-ton ammonia/water absorption chiller is developed and validated using the flow-sheeting software Aspen-Plus. First an appropriate thermodynamic property model for the ammonia/water fluid mixture is selected. To this purpose nine methods from the software library are pre-selected and tested, but none of the methods predicts the VLE (vapour–liquid equilibrium) with sufficient accuracy. The interaction parameters of these models are then determined by fitting the equations of state (EOS) to VLE data. It is finally found that the Boston–Mathias modified Peng–Robinson EOS with fitted parameters predicts most accurately the VLE for the temperature and pressure ranges encountered in commercial chillers. A simulation model of the machine is then developed. The simulation results are found to be in good agreement with data from literature at a cooling air temperature of 35 ºC. The heat transfer characteristics (UA) of the various heat exchangers of the machine are then determined and the model modified to make it accept these (UA) as input parameters. The comparison of the simulation predictions at cooling air temperatures of 26.7 and 38 ºC with the bibliographical data showed good concordance. The proposed model could be very useful for the analysis and performance prediction of the commercial absorption chiller. - Highlights: • A commercial NH 3 /H 2 O absorption chiller is simulated using the software Aspen-Plus. • Peng-Robinson-Boston-Mathias equation of state is used to predict VLE of NH 3 /H 2 O fluid mixture. • A steady-state model describing the chiller operation is developed. • The model predicts the internal operating conditions and COP of the chiller.

  5. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    Directory of Open Access Journals (Sweden)

    Javier Fontalvo Alzate

    2014-05-01

    Full Text Available Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed description of how to implement this integration. The interface between Matlab and Aspen Plus is accomplished by sending the relevant information from Aspen Plus to Excel, which feeds the information to a Matlab routine. Once the Matlab routine processes the information, it is returned to Excel and to Aspen Plus. This paper includes the Excel and Matlab template files so the reader can implement their own simulations. By applying the protocol described here, a hybrid distillation-vapor permeation system has been simulated as an example of the applications that can be implemented. For the hybrid system, the effect of membrane selectivity on membrane area and reboiler duty for the partial dehydration of ethanol is studied. Very high selectivities are not necessarily required for an optimum hybrid distillation and vapor permeation system.

  6. Cost evaluation of cellulase enzyme for industrial-scale cellulosic ethanol production based on rigorous Aspen Plus modeling.

    Science.gov (United States)

    Liu, Gang; Zhang, Jian; Bao, Jie

    2016-01-01

    Cost reduction on cellulase enzyme usage has been the central effort in the commercialization of fuel ethanol production from lignocellulose biomass. Therefore, establishing an accurate evaluation method on cellulase enzyme cost is crucially important to support the health development of the future biorefinery industry. Currently, the cellulase cost evaluation methods were complicated and various controversial or even conflict results were presented. To give a reliable evaluation on this important topic, a rigorous analysis based on the Aspen Plus flowsheet simulation in the commercial scale ethanol plant was proposed in this study. The minimum ethanol selling price (MESP) was used as the indicator to show the impacts of varying enzyme supply modes, enzyme prices, process parameters, as well as enzyme loading on the enzyme cost. The results reveal that the enzyme cost drives the cellulosic ethanol price below the minimum profit point when the enzyme is purchased from the current industrial enzyme market. An innovative production of cellulase enzyme such as on-site enzyme production should be explored and tested in the industrial scale to yield an economically sound enzyme supply for the future cellulosic ethanol production.

  7. A review of the potential effects of climate change on quaking aspen (Populus tremuloides) in the Western United States and a new tool for surveying sudden aspen decline

    Science.gov (United States)

    Toni Lyn Morelli; Susan C. Carr

    2011-01-01

    We conducted a literature review of the effects of climate on the distribution and growth of quaking aspen (Populus tremuloides Michx.) in the Western United States. Based on our review, we summarize models of historical climate determinants of contemporary aspen distribution. Most quantitative climate-based models linked aspen presence and growth...

  8. Assessing aspen using remote sensing

    Science.gov (United States)

    Randy Hamilton; Kevin Megown; Jeff DiBenedetto; Dale Bartos; Anne Mileck

    2009-01-01

    Large areas of aspen (Populus tremuloides) have disappeared and continue to disappear from western forests due to successional decline and sudden aspen decline (SAD). This loss of aspen ecosystems negatively impacts watersheds, wildlife, plants, and recreation. Much can still be done to restore aspen if timely and appropriate action is taken. However, land managers...

  9. Modelling of an industrial NGL-Recovery unit considering environmental and economic impacts

    International Nuclear Information System (INIS)

    Sharratt, P. N.; Hernandez-Enriquez, A.; Flores-Tlacuahuac, A.

    2009-01-01

    In this work, an integrated model is presented that identifies key areas in the operation of a cryogenic NGL-recovery unit. This methodology sets out to provide deep understanding of various interrelationship across multiple plant operating factors including reliability, which could be essential for substantial improvement of process performance. The integrated model has been developed to predict the economic and environmental impacts of a real cryogenic unit (600 MMCUF/D) during normal operation, and has been built in Aspen TM. (Author)

  10. Global modeling of Hanford tank waste pretreatment alternatives within a total cleanup system using ASPEN PLUS trademark

    International Nuclear Information System (INIS)

    Knutson, B.J.; Jansen, G. Jr.; Zimmerman, B.D.; Niccoli, L.G.; Lauerhass, L.

    1994-11-01

    The purpose of this work is to evaluate and compare radionuclide separations/processing technologies being developed or considered as Hanford tank waste pretreatment alternatives. These technologies are integrated into a total cleanup system that includes tank waste retrieval, treatment, and disposal. Current Hanford flowsheets typically include only mature, developed technologies, not new technologies. Thus, this work examines the impact/benefits of inserting new technologies into Hanford flowsheets. Waste treatment must produce disposal fractions which are less troublesome than the original material. Researchers seeking effective treatment methods may lack the tools or expertise to fully understand the implications of their approach in terms of secondary and tertiary waste streams or the extent to which a unique new process will affect upstream or downstream processes. This work has developed and demonstrated mass balance methods that clarify the effect of including individual processes in an integrated waste treatment system, such as the Hanford cleanup system. The methods provide a measure of treatment effectiveness and a format for the researcher to understand waste stream interrelationships and determine how a particular treatment technology can best be used in a cleanup system. A description of the Hanford tank waste cleanup model developed using the ASPEN PLUS flowsheet simulation tool is given. Important aspects of the modeling approach are discussed along with a description of how performance measures were developed and integrated within the simulation to evaluate and compare various Hanford tank waste pretreatment alternatives

  11. Modeling solubility of CO2/hydrocarbon gas in ionic liquid ([emim][FAP]) using Aspen Plus simulations.

    Science.gov (United States)

    Bagchi, Bishwadeep; Sati, Sushmita; Shilapuram, Vidyasagar

    2017-08-01

    The Peng-Robinson equation of state with quadratic van der Waals (vdW) mixing rule model was chosen to perform the thermodynamic calculations in Flash3 column of Aspen Plus to predict the solubility of CO 2 or any one of the hydrocarbons (HCs) among methane, ethane, propane, and butane in an ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([emim][FAP]). Bubble point pressure, solubility, bubble point temperature, fugacity, and partial molar volume at infinite dilution were obtained from the simulations, and enthalpy of absorption, Gibbs free energy of solvation, and entropy change of absorption were estimated by thermodynamic relations. Results show that carbon chain length has a significant effect on the bubble point pressure. Methane has the highest bubble point pressure among all the considered HCs and CO 2 . The bubble point pressure and fugacity variation with temperature is different for CO 2 as compared to HCs for mole fractions above 0.2. Two different profiles are noticed for enthalpy of absorption when plotted as a function of mole fraction of gas soluble in IL. Partial molar volume of CO 2 decreases with increase in temperature in [emim][FAP], while it is increased for HCs. Bubble point temperature decreases with increase in the mole fraction of the solute. Entropy of solvation increases with temperature till a particular value followed by a decrease with further increase in temperature. Gibbs free energy change of solvation showed that the process of solubility was spontaneous.

  12. Aspen, climate, and sudden decline in western USA

    Science.gov (United States)

    Gerald E. Rehfeldt; Dennis E. Ferguson; Nicholas L. Crookston

    2009-01-01

    A bioclimate model predicting the presence or absence of aspen, Populus tremuloides, in western USA from climate variables was developed by using the Random Forests classification tree on Forest Inventory data from about 118,000 permanent sample plots. A reasonably parsimonious model used eight predictors to describe aspen's climate profile. Classification errors...

  13. Economic communication model set

    Science.gov (United States)

    Zvereva, Olga M.; Berg, Dmitry B.

    2017-06-01

    This paper details findings from the research work targeted at economic communications investigation with agent-based models usage. The agent-based model set was engineered to simulate economic communications. Money in the form of internal and external currencies was introduced into the models to support exchanges in communications. Every model, being based on the general concept, has its own peculiarities in algorithm and input data set since it was engineered to solve the specific problem. Several and different origin data sets were used in experiments: theoretic sets were estimated on the basis of static Leontief's equilibrium equation and the real set was constructed on the basis of statistical data. While simulation experiments, communication process was observed in dynamics, and system macroparameters were estimated. This research approved that combination of an agent-based and mathematical model can cause a synergetic effect.

  14. Wood Quality and Growth Characterization across Intra- and Inter-Specific Hybrid Aspen Clones

    Directory of Open Access Journals (Sweden)

    Shawn D. Mansfield

    2013-09-01

    Full Text Available Trembling aspen (Populus tremuloides Michx. is one of the most abundant poplar species in North America; it is native, displays substantial breadth in distribution inhabiting several geographical and climatic ecoregions, is notable for its rapid growth, and is ecologically and economically important. As the demand for raw material continues to increase rapidly, there is a pressing need to improve both tree quality and growth rates via breeding efforts. Hybridization is considered one of the most promising options to simultaneously accelerate these tree characteristics, as it takes advantage of heterosis. Two aspen species showing particular promise for hybridization with trembling aspen are European aspen (P. tremula and Chinese aspen (P. davidiana because their native climates are similar to that of P. tremuloides and are also very easy to hybridize. In 2003, aspen clones were planted in Athabasca, Alberta from the following species crosses: open pollinated (OP P. tremuloides (NN, OP P. davidiana (CC, P. tremula × P. tremula (EE, P. tremula × P. tremuloides (EN, and P. tremuloides × P. davidiana (CN. In November 2010, growth measurements and core samples were taken from seven-year field grown clones. Comparisons of the mean growth and cell wall traits were made between crosses using generalized linear model least squares means tests for stem volume, fiber length, fiber width, coarseness, wood density, microfibril angle, total cell wall carbohydrate and lignin content, and lignin composition. The results clearly indicated that the inter-specific crosses offer a means to breed for more desirable wood characteristics than the intra-specific Populus spp. crosses.

  15. Molecular tools and aspen management: A primer and prospectus

    Science.gov (United States)

    Karen E. Mock; Bryce A. Richardson; Paul G. Wolf

    2013-01-01

    Aspen (Populus tremuloides) isaniconic species in North American landscapes, highly valued for recreation, fiber, wildlife and livestock forage, carbon sequestration, biodiversity, and as a fuelbreak. However, there are rising concerns about the ability of aspen to persist in portions of its range, based on bioclimatic modeling, physiological thresholds and mortality...

  16. Approach and development strategy for an agent-based model of economic confidence.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Pryor, Richard J.; Jorgensen, Craig Reed

    2004-08-01

    We are extending the existing features of Aspen, a powerful economic modeling tool, and introducing new features to simulate the role of confidence in economic activity. The new model is built from a collection of autonomous agents that represent households, firms, and other relevant entities like financial exchanges and governmental authorities. We simultaneously model several interrelated markets, including those for labor, products, stocks, and bonds. We also model economic tradeoffs, such as decisions of households and firms regarding spending, savings, and investment. In this paper, we review some of the basic principles and model components and describe our approach and development strategy for emulating consumer, investor, and business confidence. The model of confidence is explored within the context of economic disruptions, such as those resulting from disasters or terrorist events.

  17. Aspen Delineation - Inyo National Forest [ds366

    Data.gov (United States)

    California Natural Resource Agency — The database represents delineations of known aspen stands where aspen assessments were collected in the Inyo National Forest, Inyo County, California. The Inyo...

  18. Aspen Delineation - Klamath National Forest [ds370

    Data.gov (United States)

    California Department of Resources — The database represents polygons of aspen stands in the Klamath National Forest, Siskiyou County, California. The Klamath National Forest Region 5 Vegetation aspen...

  19. Integrated Ecological-Economic Models

    OpenAIRE

    John Tschirhart

    2009-01-01

    Scientific evidence suggests that economic activity is threatening global biodiversity in ways that could severely degrade nature's flow of ecosystem services. Yet, there is relatively little work in economics that addresses biodiversity loss. Some economists have called for better integration of economic and ecological models to address biodiversity and the attendant ecosystem services. Current integrated approaches in economics are discussed, and they take in ecosystem services, ecosystem e...

  20. Manipulations to regenerate aspen ecosystems

    Science.gov (United States)

    Wayne D. Shepperd

    2001-01-01

    Vegetative regeneration of aspen can be initiated through manipulations that provide hormonal stimulation, proper growth environment, and sucker protection - the three elements of the aspen regeneration triangle. The correct course of action depends upon a careful evaluation of the size, vigor, age, and successional status of the existing clone. Soils and site...

  1. Cankers on Western Quaking Aspen

    Science.gov (United States)

    David W. Johnson; Jerome S. Beatty; Thomas E. Hinds

    1995-01-01

    Long appreciated for its esthetic and shade tree value and its importance for wildlife, aspen is also capable of excellent growth and high yields and thus is an important commercial timber species. However, aspen has one major drawback-its soft bark is easily wounded by abiotic factors, animals, and insects. Subsequently, these wounds can be invaded by disease...

  2. Numerical modeling of economic uncertainty

    DEFF Research Database (Denmark)

    Schjær-Jacobsen, Hans

    2007-01-01

    Representation and modeling of economic uncertainty is addressed by different modeling methods, namely stochastic variables and probabilities, interval analysis, and fuzzy numbers, in particular triple estimates. Focusing on discounted cash flow analysis numerical results are presented, comparisons...

  3. Simulation and statistical analysis for the optimization of nitrogen liquefaction plant with cryogenic Claude cycle using process modeling tool: ASPEN HYSYS

    Science.gov (United States)

    Joshi, D. M.

    2017-09-01

    Cryogenic technology is used for liquefaction of many gases and it has several applications in food process engineering. Temperatures below 123 K are considered to be in the field of cryogenics. Extreme low temperatures are a basic need for many industrial processes and have several applications, such as superconductivity of magnets, space, medicine and gas industries. Several methods can be used to obtain the low temperatures required for liquefaction of gases. The process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure, which is below the critical pressure, is the basic liquefaction process. Different cryogenic cycle configurations are designed for getting the liquefied form of gases at different temperatures. Each of the cryogenic cycles like Linde cycle, Claude cycle, Kapitza cycle or modified Claude cycle has its own advantages and disadvantages. The placement of heat exchangers, Joule-Thompson valve and turboexpander decides the configuration of a cryogenic cycle. Each configuration has its own efficiency according to the application. Here, a nitrogen liquefaction plant is used for the analysis purpose. The process modeling tool ASPEN HYSYS can provide a software simulation approach before the actual implementation of the plant in the field. This paper presents the simulation and statistical analysis of the Claude cycle with the process modeling tool ASPEN HYSYS. It covers the technique used to optimize the liquefaction of the plant. The simulation results so obtained can be used as a reference for the design and optimization of the nitrogen liquefaction plant. Efficient liquefaction will give the best performance and productivity to the plant.

  4. Simulating economic effects of disruptions in the telecommunications infrastructure.

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Roger Gary; Barton, Dianne Catherine; Reinert, Rhonda K.; Eidson, Eric D.; Schoenwald, David Alan

    2004-01-01

    CommAspen is a new agent-based model for simulating the interdependent effects of market decisions and disruptions in the telecommunications infrastructure on other critical infrastructures in the U.S. economy such as banking and finance, and electric power. CommAspen extends and modifies the capabilities of Aspen-EE, an agent-based model previously developed by Sandia National Laboratories to analyze the interdependencies between the electric power system and other critical infrastructures. CommAspen has been tested on a series of scenarios in which the communications network has been disrupted, due to congestion and outages. Analysis of the scenario results indicates that communications networks simulated by the model behave as their counterparts do in the real world. Results also show that the model could be used to analyze the economic impact of communications congestion and outages.

  5. Using Aspen plus in thermodynamics instruction a step-by-step guide

    CERN Document Server

    Sandler, Stanley I

    2015-01-01

    A step-by-step guide for students (and faculty) on the use of Aspen in teaching thermodynamics Used for a wide variety of important engineering tasks, Aspen Plus software is a modeling tool used for conceptual design, optimization, and performance monitoring of chemical processes. After more than twenty years, it remains one of the most popular and powerful chemical engineering simulation programs used both industrially and academically. Using Aspen Plus in Thermodynamics Instruction: A Step by Step Guide introduces the reader to the use of Aspen Plus in courses in thermodynamics. It prov

  6. Global Economic Models

    DEFF Research Database (Denmark)

    Fontoynont, Marc; de Boer, Jan; Rötlander, Johan

    of building are retrofit operation more profitable, How do various parameters influence the payback time (investment costs, efficacy of luminaires and sources, cost of electricity, etc.) Then we have investigated various financial models to initiate successful investments in retrofit operations, Direct...... investment by the user, with significant benefits after the payback time Investment by the user with specific loan. This extends payback time, but doe nor require too high of a financial contribution at the beginning. Leasing of the entire installation: the building owner does not own the installation....... The lighting installation is rented (installation and operation is supplied by a third party), From our experience, it appears that leasing options are the best way to trigger lighting retrofit to overcome the barriers associated to investment. However such possibilities requires the benefits associated...

  7. Testing a hydraulic trait based model of stomatal control: results from a controlled drought experiment on aspen (Populus tremuloides, Michx.) and ponderosa pine (Pinus ponderosa, Douglas)

    Science.gov (United States)

    Love, D. M.; Venturas, M.; Sperry, J.; Wang, Y.; Anderegg, W.

    2017-12-01

    Modeling approaches for tree stomatal control often rely on empirical fitting to provide accurate estimates of whole tree transpiration (E) and assimilation (A), which are limited in their predictive power by the data envelope used to calibrate model parameters. Optimization based models hold promise as a means to predict stomatal behavior under novel climate conditions. We designed an experiment to test a hydraulic trait based optimization model, which predicts stomatal conductance from a gain/risk approach. Optimal stomatal conductance is expected to maximize the potential carbon gain by photosynthesis, and minimize the risk to hydraulic transport imposed by cavitation. The modeled risk to the hydraulic network is assessed from cavitation vulnerability curves, a commonly measured physiological trait in woody plant species. Over a growing season garden grown plots of aspen (Populus tremuloides, Michx.) and ponderosa pine (Pinus ponderosa, Douglas) were subjected to three distinct drought treatments (moderate, severe, severe with rehydration) relative to a control plot to test model predictions. Model outputs of predicted E, A, and xylem pressure can be directly compared to both continuous data (whole tree sapflux, soil moisture) and point measurements (leaf level E, A, xylem pressure). The model also predicts levels of whole tree hydraulic impairment expected to increase mortality risk. This threshold is used to estimate survivorship in the drought treatment plots. The model can be run at two scales, either entirely from climate (meteorological inputs, irrigation) or using the physiological measurements as a starting point. These data will be used to study model performance and utility, and aid in developing the model for larger scale applications.

  8. Aspen Delineation - Sequoia National Forest [ds378

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SEQUOIA_NF_PTS) collected in aspen stands in the Cannell Meadows Ranger...

  9. Aspen Delineation - Sierra State Parks [ds380

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SIERRA_SP_PTS) collected in aspen stands on lands administered by the...

  10. Aspen Delineation - Lassen National Forest [ds372

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (LASSEN_NF_EAGLELAKE_PTS) collected in aspen stands in the in the Eagle...

  11. Aspen Delineation - Plumas National Forest [ds374

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_PTS) collected in aspen stands in the Plumas National Forest,...

  12. Model confirmation in climate economics.

    Science.gov (United States)

    Millner, Antony; McDermott, Thomas K J

    2016-08-02

    Benefit-cost integrated assessment models (BC-IAMs) inform climate policy debates by quantifying the trade-offs between alternative greenhouse gas abatement options. They achieve this by coupling simplified models of the climate system to models of the global economy and the costs and benefits of climate policy. Although these models have provided valuable qualitative insights into the sensitivity of policy trade-offs to different ethical and empirical assumptions, they are increasingly being used to inform the selection of policies in the real world. To the extent that BC-IAMs are used as inputs to policy selection, our confidence in their quantitative outputs must depend on the empirical validity of their modeling assumptions. We have a degree of confidence in climate models both because they have been tested on historical data in hindcasting experiments and because the physical principles they are based on have been empirically confirmed in closely related applications. By contrast, the economic components of BC-IAMs often rely on untestable scenarios, or on structural models that are comparatively untested on relevant time scales. Where possible, an approach to model confirmation similar to that used in climate science could help to build confidence in the economic components of BC-IAMs, or focus attention on which components might need refinement for policy applications. We illustrate the potential benefits of model confirmation exercises by performing a long-run hindcasting experiment with one of the leading BC-IAMs. We show that its model of long-run economic growth-one of its most important economic components-had questionable predictive power over the 20th century.

  13. Mathematical modelling in economic processes.

    Directory of Open Access Journals (Sweden)

    L.V. Kravtsova

    2008-06-01

    Full Text Available In article are considered a number of methods of mathematical modelling of economic processes and opportunities of use of spreadsheets Excel for reception of the optimum decision of tasks or calculation of financial operations with the help of the built-in functions.

  14. Aspen's ecological role in the West

    Science.gov (United States)

    William H. Romme; Lisa Floyd-Hanna; David D. Hanna; Elisabeth Bartlett

    2001-01-01

    Aspen exhibits a variety of ecological roles. In southern Colorado, the 1880 landscape mosaic contained a range of stand ages, of which half were >70 years old and half were younger. Pure aspen stands in southern Colorado are widespread and may result from previous short fire intervals that eliminated local conifer seed sources. Aspen regeneration in northern...

  15. Energy-economic policy modeling

    Science.gov (United States)

    Sanstad, Alan H.

    2018-01-01

    Computational models based on economic principles and methods are powerful tools for understanding and analyzing problems in energy and the environment and for designing policies to address them. Among their other features, some current models of this type incorporate information on sustainable energy technologies and can be used to examine their potential role in addressing the problem of global climate change. The underlying principles and the characteristics of the models are summarized, and examples of this class of model and their applications are presented. Modeling epistemology and related issues are discussed, as well as critiques of the models. The paper concludes with remarks on the evolution of the models and possibilities for their continued development.

  16. Economic and Technical Assessment of Wood Biomass Fuel Gasification for Industrial Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Anastasia M. Gribik; Ronald E. Mizia; Harry Gatley; Benjamin Phillips

    2007-09-01

    This project addresses both the technical and economic feasibility of replacing industrial gas in lime kilns with synthesis gas from the gasification of hog fuel. The technical assessment includes a materials evaluation, processing equipment needs, and suitability of the heat content of the synthesis gas as a replacement for industrial gas. The economic assessment includes estimations for capital, construction, operating, maintenance, and management costs for the reference plant. To perform these assessments, detailed models of the gasification and lime kiln processes were developed using Aspen Plus. The material and energy balance outputs from the Aspen Plus model were used as inputs to both the material and economic evaluations.

  17. The Economics of Online Dating: A Course in Economic Modeling

    Science.gov (United States)

    Monaco, Andrew J.

    2018-01-01

    The author discusses the development of a unique course, The Economics of Online Dating. The course is an upper-level undergraduate course that combines intensive discussion, peer review, and economic theory to teach modeling skills to undergraduates. The course uses the framework of "online dating," interpreted broadly, as a point of…

  18. HOMER Economic Models - US Navy

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Jason William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Myers, Kurt Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This LETTER REPORT has been prepared by Idaho National Laboratory for US Navy NAVFAC EXWC to support in testing pre-commercial SIREN (Simulated Integration of Renewable Energy Networks) computer software models. In the logistics mode SIREN software simulates the combination of renewable power sources (solar arrays, wind turbines, and energy storage systems) in supplying an electrical demand. NAVFAC EXWC will create SIREN software logistics models of existing or planned renewable energy projects at five Navy locations (San Nicolas Island, AUTEC, New London, & China Lake), and INL will deliver additional HOMER computer models for comparative analysis. In the transient mode SIREN simulates the short time-scale variation of electrical parameters when a power outage or other destabilizing event occurs. In the HOMER model, a variety of inputs are entered such as location coordinates, Generators, PV arrays, Wind Turbines, Batteries, Converters, Grid costs/usage, Solar resources, Wind resources, Temperatures, Fuels, and Electric Loads. HOMER's optimization and sensitivity analysis algorithms then evaluate the economic and technical feasibility of these technology options and account for variations in technology costs, electric load, and energy resource availability. The Navy can then use HOMER’s optimization and sensitivity results to compare to those of the SIREN model. The U.S. Department of Energy (DOE) Idaho National Laboratory (INL) possesses unique expertise and experience in the software, hardware, and systems design for the integration of renewable energy into the electrical grid. NAVFAC EXWC will draw upon this expertise to complete mission requirements.

  19. Aspen Characteristics - Klamath National Forest [ds369

    Data.gov (United States)

    California Natural Resource Agency — The database represents point locations and associated stand assessment data collected with known aspen stands in the Klamath National Forest, Siskiyou County,...

  20. Aspen Characteristics - Klamath National Forest [ds369

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected with known aspen stands in the Klamath National Forest, Siskiyou County,...

  1. Aspen Characteristics - Sierra State Parks [ds379

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands on lands administrated by the Sierra District, California...

  2. Aspen Characteristics - Plumas National Forest [ds373

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Beckwourth Ranger District...

  3. Aspen Characteristics - Sequoia National Forest [ds377

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Cannell Meadows Ranger District, Sequoia National...

  4. Aspen Delineation - El Dorado National Forest [ds364

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands, where aspen assessments were gathered in the Eldorado National Forest, Eldorado and Amador Counties,...

  5. Aspen Delineation - Klamath National Forest, EUI [ds368

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands where aspen assessments were collected in the Klamath National Forest, Siskiyou County, California. The...

  6. Production economic models of fisheries

    DEFF Research Database (Denmark)

    Andersen, Jesper Levring

    The overall purpose of this PhD thesis is to investigate different aspects of fishermen’s behaviour using production economic models at the individual and industry levels. Three parts make up this thesis. The first part provides an overview of the thesis. The second part consists of four papers a...... in relation to an ITQ system, including concentration, specialisation, market activity and price changes. Finally, plausible consequences of exogenous chocks and changes in management practice in the form of mesh size increases are considered....... via individual learning and adjustments in output mix. All the papers included in Part II: Modelling and Evaluating Fishermen’s Behaviour consider factors influencing fishermen’s behaviour. Knowledge about these factors is important to give a correct description of fishermen’s behaviour. However....... They concern the ability to learn best-practice (catch-up) and the ability to change the input and output composition (mix). The framework is then adapted to a dataset from the Danish fishery. Not surprisingly, the gains rise with increased behavioural flexibility. Under the most restrictive assumptions...

  7. The Need of a New Economic Model

    Directory of Open Access Journals (Sweden)

    Alexandru Cătălin POPA

    2012-02-01

    Full Text Available The current global economic crisis has proven to be unpredictable for most decision-makers worldwide. Moreover, beliefs deeply embedded in the minds of economists about economics, about the virtues of capitalism and free market began to falter. Sooner or later the current crisis will end. The problem that arises and to which the economic science must answer is whether anything should be changed in the current world economic order and especially what exactly. It is quite vital to ask ourselves today in what kind of society we want to live and whether the current economic model, a model mainly based on monetarist ideas, is helping us to achieve those wishes. In addition to analyzing the root causes that led to the current economic crisis, this article aims to analyze whether the current economic model must change and to outline the features of a possible new model.

  8. Nitrogen mineralization in the aspen ecosystem

    Science.gov (United States)

    M. C. Amacher; A. D. Johnson; T. Christopherson; D. E. Kutterer; D. L. Bartos; J. Kotuby-Amacher

    1999-01-01

    Aspen (Populus tremuloides) are in decline throughout the interior western U.S. because of conifer invasion, fire suppression, and overbrowsing by domestic livestock and native ungulates. Aspen restoration requires disturbances such as fire or cutting and exclosures to protect against overbrowsing. We measured the effects of the 1996 Pole Creek fire, Fishlake NF, UT on...

  9. The Fate of Aspen in a World with Diminishing Snowpacks

    Science.gov (United States)

    Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Kemp, K. B.

    2010-12-01

    Aspen (Populus tremuloides) productivity is tightly coupled with soil moisture. In the mountainous regions of the western USA, annual replenishment of soil moisture commonly occurs during snowmelt. Therefore, snow pack depth and duration can play an important role in sustaining aspen productivity. The presence of almost 50 years of detailed climate data across an elevational transect in the Reynolds Creek Experimental Watershed (RCEW) in southwestern Idaho offers a novel opportunity to better understand the role of shifting precipitation patterns on aspen productivity. Over the past 50 years, the proportion of the precipitation falling in the form of snow decreased by almost a factor of 2 at mid to low elevations in the RCEW, coupled with a roughly four week advance of snow ablation, and decline of large snow drifts that release moisture into the early summer. Results from growth ring increment, stable isotope analysis, sapflux and a process model (Biome BGC), will be used to determine the impact of shifting precipitation patterns on tree productivity along this transect over the past 50 years. Aspen trees located on moist microsites continue to transpire water and maintain high stomatal conductance 21 days later in the growing season relative to individuals on drier microsites. Predictions of net primary productivity (NPP) in aspen are very sensitive to precipitation patterns. NPP becomes negative as early as day 183 (90 days post budbreak) for years with little winter and spring precipitation whereas, in years with ample winter and spring precipitation, NPP remains positive until day 260 when leaf fall occurs. These results give unique insight into the conditions that deciduous tree species will encounter in a warming climate where snow water equivalent continues to diminish and soil moisture declines soon after budbreak occurs.

  10. Aspen Code Development Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    none,; Cherry, Robert S. [INL; Richard, Boardman D. [INL

    2013-10-03

    Wyoming has a wealth of primary energy resources in the forms of coal, natural gas, wind, uranium, and oil shale. Most of Wyoming?s coal and gas resources are exported from the state in unprocessed form rather than as refined higher value products. Wyoming?s leadership recognizes the opportunity to broaden the state?s economic base energy resources to make value-added products such as synthetic vehicle fuels and commodity chemicals. Producing these higher value products in an environmentally responsible manner can benefit from the use of clean energy technologies including Wyoming?s abundant wind energy and nuclear energy such as new generation small modular reactors including the high temperature gas-cooled reactors.

  11. Using Aspen simulation package to determine solubility of mixed salts in TRU waste evaporator bottoms

    Energy Technology Data Exchange (ETDEWEB)

    Hatchell, J.L.

    1998-03-01

    Nitric acid from plutonium process waste is a candidate for waste minimization by recycling. Process simulation software packages, such as Aspen, are valuable tools to estimate how effective recovery processes can be, however, constants in equations of state for many ionic components are not in their data libraries. One option is to combine single salt solubility`s in the Aspen model for mixed salt system. Single salt solubilities were regressed in Aspen within 0.82 weight percent of literature values. These were combined into a single Aspen model and used in the mixed salt studies. A simulated nitric acid waste containing mixed aluminum, calcium, iron, magnesium and sodium nitrate was tested to determine points of solubility between 25 and 100 C. Only four of the modeled experimental conditions, at 50 C and 75 C, produced a saturated solution. While experimental results indicate that sodium nitrate is the first salt to crystallize out, the Aspen computer model shows that the most insoluble salt, magnesium nitrate, the first salt to crystallize. Possible double salt formation is actually taking place under experimental conditions, which is not captured by the Aspen model.

  12. Prescribed fire, elk, and aspen in Grand Teton National Park

    Science.gov (United States)

    Ron Steffens; Diane Abendroth

    2001-01-01

    In Grand Teton National Park, a landscape-scale assessment of regeneration in aspen has assisted park managers in identifying aspen stands that may be at risk due to a number of interrelated factors, including ungulate browsing and suppression of wildland fire. The initial aspen survey sampled an estimated 20 percent of the park's aspen stands. Assessment of these...

  13. Economic models for battery energy storage

    International Nuclear Information System (INIS)

    Reckrodt, R.C.; Anderson, M.D.; Kluczny, R.M.

    1990-01-01

    While the technology required to produce viable Battery Energy Storage System exists, the economic feasibility (cost vs. benefits) of building these systems requires justification. First, a generalized decision diagram was developed to ensure that all of the economic factors were considered and properly related for the customer-side-of-the meter. Next, two economic models that had consistently given differing results were compared. One was the McKinney model developed at UM-Rolla in 1987; the second was the SYSPLAN model developed by Battelle. Differences were resolved on a point by point basis with reference to the current economic environment. The economic model was upgraded to include the best of both models based on the resolution of these differences. The upgrades were implemented as modifications to the original SYSPLAN (1986 version) to preserve user friendliness. In this paper four specific cases are evaluated and compared. The results are as predicted, since comparison was made with two known models

  14. Network models in economics and finance

    CERN Document Server

    Pardalos, Panos; Rassias, Themistocles

    2014-01-01

    Using network models to investigate the interconnectivity in modern economic systems allows researchers to better understand and explain some economic phenomena. This volume presents contributions by known experts and active researchers in economic and financial network modeling. Readers are provided with an understanding of the latest advances in network analysis as applied to economics, finance, corporate governance, and investments. Moreover, recent advances in market network analysis  that focus on influential techniques for market graph analysis are also examined. Young researchers will find this volume particularly useful in facilitating their introduction to this new and fascinating field. Professionals in economics, financial management, various technologies, and network analysis, will find the network models presented in this book beneficial in analyzing the interconnectivity in modern economic systems.

  15. Mathematical Models of Economic Growth

    NARCIS (Netherlands)

    J. Tinbergen (Jan); H.C. Bos (Henk)

    1962-01-01

    textabstractEconomics Handbook Series, edited by Seymour E. Harris. In Spanish: Modelos Matematicos del Crecimiento Económico, Series ‘Biblioteca de Ciencias Sociales’, Aguilar, Madrid, 1966, XVI + 165 p. In French: Modèles Mathématiques de Croissance Economique. Series ‘Techniques Economiques

  16. Implementing ASPEN on the CRAY computer

    International Nuclear Information System (INIS)

    Duerre, K.H.; Bumb, A.C.

    1981-01-01

    This paper describes our experience in converting the ASPEN program for use on our CRAY computers at the Los Alamos National Laboratory. The CRAY computer is two-to-five times faster than a CDC-7600 for scalar operations, is equipped with up to two million words of high-speed storage, and has vector processing capability. Thus, the CRAY is a natural candidate for programs that are the size and complexity of ASPEN. Our approach to converting ASPEN and the conversion problems are discussed, including our plans for optimizing the program. Comparisons of run times for test problems between the CRAY and IBM 370 computer versions are presented

  17. Managed Mixtures of Aspen and White Spruce 21 to 25 Years after Establishment

    Directory of Open Access Journals (Sweden)

    Richard Kabzems

    2015-12-01

    Full Text Available Intimate mixtures of trembling aspen (Populus tremuloides Michx. and white spruce (Picea glauca (Moench Voss are a key feature of western Canadian boreal forests. These mixtures have the potential to produce high yields of merchantable fibre and provide numerous ecological services. Achievement of this potential has been difficult, and often expensive, to realize as a regeneration goal in managed forests. We report 21 to 25 year results of managed mixtures on two study sites where the white spruce was planted, and the density of aspen natural regeneration manipulated within five years of the stand initiation disturbance. On both sites, white spruce mortality did not increase with increasing aspen density. While height and diameter growth of white spruce declined with increasing aspen density, the effect was not entirely consistent across the two sites. Abrasion from aspen branches was the most common source of damage to spruce crowns. Mixed stands had greater merchantable volume production than pure spruce stands based on model projections. Application of aspen harvest at year 60, while protecting the spruce component for a second harvest entry at year 90, was projected to optimize combined yield for the mixedwood stands.

  18. Study on Chinese Low Carbon Economic Model

    OpenAIRE

    Huifeng Li; Xiaofang Wang

    2010-01-01

    Global warming, which is caused by over consumption of fossil energy during economic development in human society, threatens global ecological balance, tampers social and economic development, imperils energy security, ecological safety, water and food safety, and endangers the entire human race. Low carbon economy is a new economic development model based on low energy consumption, low pollution, and low-emission-based. This paper analyzes the Status quo and Limits of the Chinese Low Carbon ...

  19. HTGR Application Economic Model Users' Manual

    International Nuclear Information System (INIS)

    Gandrik, A.M.

    2012-01-01

    The High Temperature Gas-Cooled Reactor (HTGR) Application Economic Model was developed at the Idaho National Laboratory for the Next Generation Nuclear Plant Project. The HTGR Application Economic Model calculates either the required selling price of power and/or heat for a given internal rate of return (IRR) or the IRR for power and/or heat being sold at the market price. The user can generate these economic results for a range of reactor outlet temperatures; with and without power cycles, including either a Brayton or Rankine cycle; for the demonstration plant, first of a kind, or nth of a kind project phases; for up to 16 reactor modules; and for module ratings of 200, 350, or 600 MWt. This users manual contains the mathematical models and operating instructions for the HTGR Application Economic Model. Instructions, screenshots, and examples are provided to guide the user through the HTGR Application Economic Model. This model was designed for users who are familiar with the HTGR design and Excel and engineering economics. Modification of the HTGR Application Economic Model should only be performed by users familiar with the HTGR and its applications, Excel, and Visual Basic.

  20. Process and economic model of in-field heavy oil upgrading using aqueous pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Thorsness, C. B., LLNL

    1997-01-21

    A process and economic model for aqueous pyrolysis in-field upgrading of heavy oil has been developed. The model has been constructed using the ASPEN PLUS chemical process simulator. The process features cracking of heavy oil at moderate temperatures in the presence of water to increase oil quality and thus the value of the oil. Calculations with the model indicate that for a 464 Mg/day (3,000 bbl/day) process, which increases the oil API gravity of the processed oil from 13.5{degree} to 22.4{degree}, the required value increase of the oil would need to be at least $2.80/Mg{center_dot}{degree}API($0.40/bbl{center_dot}{degree}API) to make the process economically attractive. This level of upgrading has been demonstrated in preliminary experiments with candidate catalysts. For improved catalysts capable of having the coke make and increasing the pyrolysis rate, a required price increase for the oil as low as $1.34/Mg{center_dot}{degree}API ($0.21/bbl{center_dot}{degree}API)has been calculated.

  1. Biomass of Sacrificed Spruce/Aspen (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Dimension analysis (diameter at breast high, tree height, depth of crown), estimated leaf area, and total aboveground biomass for sacrificed spruce and aspens in...

  2. Aspen Characteristics - Lassen National Forest [ds371

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected in aspen stands in the in the Eagle Lake Ranger District, Lassen National...

  3. What is an Economic Model?

    OpenAIRE

    Puente-Ajovin, Miguel

    2013-01-01

    Continuamente se critica a la ciencia económica en base a que sus modelos son descripciones inexactas de una realidad inabarcable y que, por tanto, carecen de un valor real. En este artículo intento dar una descripción propia de qué son los modelos económicos y por qué son tan valiosos, no solo para el progreso de la ciencia económica, sino para el razonamiento en términos económicos con el que nos debemos topar día a día. Continually, people criticizes economics on the grounds that their mod...

  4. Phosphate removal by refined aspen wood fiber treated with carboxymethyl cellulose and ferrous chloride

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min; James S. Han

    2006-01-01

    Biomass-based filtration media are of interest as an economical means to remove pollutants and nutrients found in stormwater runoff. Refined aspen wood fiber samples treated with iron salt solutions demonstrated limited capacities to remove (ortho)phosphate from test solutions. To provide additional sites for iron complex formation, and thereby impart a greater...

  5. Structural modelling of economic growth: Technological changes

    Directory of Open Access Journals (Sweden)

    Sukharev Oleg

    2016-01-01

    Full Text Available Neoclassical and Keynesian theories of economic growth assume the use of Cobb-Douglas modified functions and other aggregate econometric approaches to growth dynamics modelling. In that case explanations of economic growth are based on the logic of the used mathematical ratios often including the ideas about aggregated values change and factors change a priori. The idea of assessment of factor productivity is the fundamental one among modern theories of economic growth. Nevertheless, structural parameters of economic system, institutions and technological changes are practically not considered within known approaches, though the latter is reflected in the changing parameters of production function. At the same time, on the one hand, the ratio of structural elements determines the future value of the total productivity of the factors and, on the other hand, strongly influences the rate of economic growth and its mode of innovative dynamics. To put structural parameters of economic system into growth models with the possibility of assessment of such modes under conditions of interaction of new and old combinations is an essential step in the development of the theory of economic growth/development. It allows forming stimulation policy of economic growth proceeding from the structural ratios and relations recognized for this economic system. It is most convenient in such models to use logistic functions demonstrating the resource change for old and new combination within the economic system. The result of economy development depends on starting conditions, and on institutional parameters of velocity change of resource borrowing in favour of a new combination and creation of its own resource. Model registration of the resource is carried out through the idea of investments into new and old combinations.

  6. Thermodynamic Phase And Chemical Equilibrium At 0-110 C For The H+-K+-Na+-Cl--H2O System Up To 16 Molal And The HNO3-H2O System Up To 20 Molal Using An Association-Based Pitzer Model Compatible With ASPEN Plus

    Energy Technology Data Exchange (ETDEWEB)

    Nichols,T.T.; Taylor,D.D.

    2003-09-26

    A status is presented of the parameterization during FY2003 of an association-based Pitzer model to simulate chemical and phase equilibria of acid-chloride-nitrate-mercury aqueous electrolyte systems at 0-100 C within the industry-standard process simulator, ASPEN Plus. Compatibility with ASPEN Plus requires that the Pitzer model used be limited to the third virial coefficient and have the values of b and a1 as originally proposed by Pitzer. Two aqueous models for 0-110 C at atmospheric pressure were parameterized in FY03. The model for the aqueous H+-K+-Na+-Cl- system is applicable for 0-16 molal, and the HNO3-H2O for 0-20 molal. An association-based Pitzer activity coefficient model is combined with Henry's law to predict activity/osmotic coefficient and VLE. The chloride model also predicts KCl and NaCl solubility, while the nitric acid model has the unique capability of predicting extent of dissociation with an average absolute deviation of 1.43%. The association-based approach presented here extends the utility of the molality-based Pitzer model past 6 molal to predict activity/osmotic coefficients up to 16-20 molal. The association-based approach offers the additional benefits of predicting extent of dissociation and of allowing the Pitzer model to be fully utilized in commercial simulators, such as ASPEN Plus, that require accounting for association to implement Henry's law. The Pitzer models presented here provide the chemical process simulation engineer with a superior alternative to the Electrolyte NRTL model that can easily be used in ASPEN Plus.

  7. JEDI: Jobs and Economic Development Impact Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-13

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL's researchers to model wind energy jobs and impacts, JEDI has been expanded to also estimate the economic impacts of biofuels, coal, conventional hydro, concentrating solar power, geothermal, marine and hydrokinetic power, natural gas, photovoltaics, and transmission lines. This fact sheet focuses on JEDI for wind energy projects and is revised with 2017 figures.

  8. The modelling of economic consequences in COSYMA

    International Nuclear Information System (INIS)

    Faude, D.

    1991-01-01

    A new model for assessing the economic consequences of accidents, called COCO-1 (Cost of Consequences Off-site) has been developed jointly by NRPB and KfK under the CEC MARIA programme. This paper describes the way in which this model, together with other options, has been implemented in the ECONOMICS module of COSYMA. For consistency with the other parts of COSYMA, the coding of the ECONOMICS module is flexible: in several areas, alternative calculational methods are available and the user may select the method by which a particular cost is calculated. To some extent, economic models other than the COCO-1 model may be applied. There are two types of input data in the ECONOMICS module. These are (1) data from preceding COSYMA modules which quantify the magnitude and distribution of health effects and the impact of countermeasures, and (2) economic data, in terms of costs per unit quantity, to convert the preceding data into monetary values. The structure of the module has been determined by the form and availability of the input data, and the general structure of COSYMA. Details of the method of calculation, and the necessary input data, are discussed, for calculation of the economic consequences of the countermeasures considered in COSYMA (evacuation, relocation, sheltering, decontamination and food bans) and for early and late health effects

  9. A new green process for biodiesel production from waste oils via catalytic distillation using a solid acid catalyst – Modeling, economic and environmental analysis

    Directory of Open Access Journals (Sweden)

    Aashish Gaurav

    2016-04-01

    Full Text Available The challenges in the chemical processing industry today are environmental concerns, energy and capital costs. Catalytic distillation (CD is a green reactor technology which combines a catalytic reaction and separation via distillation in the same distillation column. Utilization of CD in chemical process development could result in capital and energy savings, and the reduction of greenhouse gases. The efficacy of CD and the economic merits, in terms of energy and equipment savings, brought by CD for the production of biodiesel from waste oil such as yellow grease is quantified. Process flow sheets for industrial routes for an annual production of 10 million gallon ASTM purity biodiesel in a conventional process (reactor followed by distillation and CD configurations are modeled in Aspen Plus. Material and energy flows, as well as sized unit operation blocks, are used to conduct an economic assessment of each process. Total capital investment, total operating and utility costs are calculated for each process. The waste oil feedstock is yellow grease containing both triglyceride and free fatty acid. Both transesterification and esterification reactions are considered in the process simulations. Results show a significant advantage of CD compared to a conventional biodiesel processes due to the reduction of distillation columns, waste streams and greenhouse gas emissions. The significant savings in capital and energy costs together with the reduction of greenhouse gases demonstrate that process intensification via CD is a feasible and new green process for the biodiesel production from waste oils. Keywords: Yellow grease, Catalytic distillation, Aspen plus economic analyzer, Process intensification

  10. Economic aspects and models for building codes

    DEFF Research Database (Denmark)

    Bonke, Jens; Pedersen, Dan Ove; Johnsen, Kjeld

    It is the purpose of this bulletin to present an economic model for estimating the consequence of new or changed building codes. The object is to allow comparative analysis in order to improve the basis for decisions in this field. The model is applied in a case study.......It is the purpose of this bulletin to present an economic model for estimating the consequence of new or changed building codes. The object is to allow comparative analysis in order to improve the basis for decisions in this field. The model is applied in a case study....

  11. Economic model of pipeline transportation systems

    Energy Technology Data Exchange (ETDEWEB)

    Banks, W. F.

    1977-07-29

    The objective of the work reported here was to develop a model which could be used to assess the economic effects of energy-conservative technological innovations upon the pipeline industry. The model is a dynamic simulator which accepts inputs of two classes: the physical description (design parameters, fluid properties, and financial structures) of the system to be studied, and the postulated market (throughput and price) projection. The model consists of time-independent submodels: the fluidics model which simulates the physical behavior of the system, and the financial model which operates upon the output of the fluidics model to calculate the economics outputs. Any of a number of existing fluidics models can be used in addition to that developed as a part of this study. The financial model, known as the Systems, Science and Software (S/sup 3/) Financial Projection Model, contains user options whereby pipeline-peculiar characteristics can be removed and/or modified, so that the model can be applied to virtually any kind of business enterprise. The several dozen outputs are of two classes: the energetics and the economics. The energetics outputs of primary interest are the energy intensity, also called unit energy consumption, and the total energy consumed. The primary economics outputs are the long-run average cost, profit, cash flow, and return on investment.

  12. Bridging Economic Theory Models and the Cointegrated Vector Autoregressive Model

    DEFF Research Database (Denmark)

    Møller, Niels Framroze

    2008-01-01

    Examples of simple economic theory models are analyzed as restrictions on the Cointegrated VAR (CVAR). This establishes a correspondence between basic economic concepts and the econometric concepts of the CVAR: The economic relations correspond to cointegrating vectors and exogeneity...... in the economic model is related to econometric concepts of exogeneity. The economic equilibrium corresponds to the so-called long-run value (Johansen 2005), the long-run impact matrix, C; captures the comparative statics and the exogenous variables are the common trends. The adjustment parameters of the CVAR...

  13. Aspen Delineation - Plumas National Forest, FRRD [ds376

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_FEATHERRIVER_PTS) collected in aspen stands in the Plumas...

  14. Simulating the Dependence of Aspen on Redistributed Snow

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Winstral, A. H.

    2013-12-01

    In mountainous regions across the western USA, the distribution of aspen (Populus tremuloides) is often directly related to heterogeneous soil moisture subsidies resulting from redistributed snow. With decades of climate and precipitation data across elevational and precipitation gradients, the Reynolds Creek Experimental Watershed (RCEW) in southwest Idaho provides a unique opportunity to study the relationship between aspen and redistributed snow. Within the RCEW, the total amount of precipitation has not changed in the past 50 years, but there are sharp declines in the percentage of the precipitation falling as snow. As shifts in the distribution of available moisture continue, future trends in aspen net primary productivity (NPP) remain uncertain. In order to assess the importance of snowdrift subsidies, NPP of three aspen stands was simulated at sites spanning elevational and precipitation gradients using the biogeochemical process model BIOME-BGC. At the aspen site experiencing the driest climate and lowest amount of precipitation from snow, approximately 400 mm of total precipitation was measured from November to March of 2008. However, peak measured snow water equivalent (SWE) held in drifts directly upslope of this stand was approximately 2100 mm, 5 times more moisture than the uniform winter precipitation layer initially assumed by BIOME-BGC. BIOME-BGC simulations in dry years forced by adjusted precipitation data resulted in NPP values approximately 30% higher than simulations assuming a uniform precipitation layer. Using BIOME-BGC and climate data from 1985-2011, the relationship between simulated NPP and measured basal area increments (BAI) improved after accounting for redistributed snow, indicating increased simulation representation. In addition to improved simulation capabilities, soil moisture data, diurnal branch water potential, and stomatal conductance observations at each site detail the use of soil moisture in the rooting zone and the onset

  15. Spatial Economics Model Predicting Transport Volume

    Directory of Open Access Journals (Sweden)

    Lu Bo

    2016-10-01

    Full Text Available It is extremely important to predict the logistics requirements in a scientific and rational way. However, in recent years, the improvement effect on the prediction method is not very significant and the traditional statistical prediction method has the defects of low precision and poor interpretation of the prediction model, which cannot only guarantee the generalization ability of the prediction model theoretically, but also cannot explain the models effectively. Therefore, in combination with the theories of the spatial economics, industrial economics, and neo-classical economics, taking city of Zhuanghe as the research object, the study identifies the leading industry that can produce a large number of cargoes, and further predicts the static logistics generation of the Zhuanghe and hinterlands. By integrating various factors that can affect the regional logistics requirements, this study established a logistics requirements potential model from the aspect of spatial economic principles, and expanded the way of logistics requirements prediction from the single statistical principles to an new area of special and regional economics.

  16. Market disruption, cascading effects, and economic recovery:a life-cycle hypothesis model.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.

    2004-11-01

    This paper builds upon previous work [Sprigg and Ehlen, 2004] by introducing a bond market into a model of production and employment. The previous paper described an economy in which households choose whether to enter the labor and product markets based on wages and prices. Firms experiment with prices and employment levels to maximize their profits. We developed agent-based simulations using Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate that multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment, but also suffer from market noise stemming from consumer churn. In this paper we introduce a bond market as a mechanism for household savings. We simulate an economy of continuous overlapping generations in which each household grows older in the course of the simulation and continually revises its target level of savings according to a life-cycle hypothesis. Households can seek employment, earn income, purchase goods, and contribute to savings until they reach the mandatory retirement age; upon retirement households must draw from savings in order to purchase goods. This paper demonstrates the simultaneous convergence of product, labor, and savings markets to their calculated equilibria, and simulates how a disruption to a productive sector will create cascading effects in all markets. Subsequent work will use similar models to simulate how disruptions, such as terrorist attacks, would interplay with consumer confidence to affect financial markets and the broader economy.

  17. Aspen biology, community classification, and management in the Blue Mountains

    Science.gov (United States)

    David K. Swanson; Craig L. Schmitt; Diane M. Shirley; Vicky Erickson; Kenneth J. Schuetz; Michael L. Tatum; David C. Powell

    2010-01-01

    Quaking aspen (Populus tremuloides Michx.) is a valuable species that is declining in the Blue Mountains of northeastern Oregon. This publication is a compilation of over 20 years of aspen management experience by USDA Forest Service workers in the Blue Mountains. It includes a summary of aspen biology and occurrence in the Blue Mountains, and a...

  18. Evaluation of burned aspen communities in Jackson Hole, Wyoming

    Science.gov (United States)

    Charles E. Kay

    2001-01-01

    Aspen has been declining in Jackson Hole for many years, a condition generally attributed to the fact that lightning fires have been aggressively suppressed since the early 1900s. It is also believed that burning will successfully regenerate aspen stands despite high elk numbers. To test this hypothesis, I evaluated 467 burned and 495 adjacent, unburned aspen stands at...

  19. Logistic map with memory from economic model

    International Nuclear Information System (INIS)

    Tarasova, Valentina V.; Tarasov, Vasily E.

    2017-01-01

    A generalization of the economic model of logistic growth, which takes into account the effects of memory and crises, is suggested. Memory effect means that the economic factors and parameters at any given time depend not only on their values at that time, but also on their values at previous times. For the mathematical description of the memory effects, we use the theory of derivatives of non-integer order. Crises are considered as sharp splashes (bursts) of the price, which are mathematically described by the delta-functions. Using the equivalence of fractional differential equations and the Volterra integral equations, we obtain discrete maps with memory that are exact discrete analogs of fractional differential equations of economic processes. We derive logistic map with memory, its generalizations, and “economic” discrete maps with memory from the fractional differential equations, which describe the economic natural growth with competition, power-law memory and crises.

  20. Agent-based modeling in ecological economics.

    Science.gov (United States)

    Heckbert, Scott; Baynes, Tim; Reeson, Andrew

    2010-01-01

    Interconnected social and environmental systems are the domain of ecological economics, and models can be used to explore feedbacks and adaptations inherent in these systems. Agent-based modeling (ABM) represents autonomous entities, each with dynamic behavior and heterogeneous characteristics. Agents interact with each other and their environment, resulting in emergent outcomes at the macroscale that can be used to quantitatively analyze complex systems. ABM is contributing to research questions in ecological economics in the areas of natural resource management and land-use change, urban systems modeling, market dynamics, changes in consumer attitudes, innovation, and diffusion of technology and management practices, commons dilemmas and self-governance, and psychological aspects to human decision making and behavior change. Frontiers for ABM research in ecological economics involve advancing the empirical calibration and validation of models through mixed methods, including surveys, interviews, participatory modeling, and, notably, experimental economics to test specific decision-making hypotheses. Linking ABM with other modeling techniques at the level of emergent properties will further advance efforts to understand dynamics of social-environmental systems.

  1. Sparse High Dimensional Models in Economics.

    Science.gov (United States)

    Fan, Jianqing; Lv, Jinchi; Qi, Lei

    2011-09-01

    This paper reviews the literature on sparse high dimensional models and discusses some applications in economics and finance. Recent developments of theory, methods, and implementations in penalized least squares and penalized likelihood methods are highlighted. These variable selection methods are proved to be effective in high dimensional sparse modeling. The limits of dimensionality that regularization methods can handle, the role of penalty functions, and their statistical properties are detailed. Some recent advances in ultra-high dimensional sparse modeling are also briefly discussed.

  2. Economical modelling of social and moral norms

    International Nuclear Information System (INIS)

    Nyborg, Karine

    2001-01-01

    Social norms and moral motivations are often ignored in economic models. It is possible, however, to model social and moral norms within the framework of economical theory. This may be useful even if the exposition is necessarily simplified. The article gives some examples. An analysis shows how the ''No Smoking Act'' may have led to a change in social norms in Norway and indirectly changed the behaviour of smokers in places where this act does not apply. Behaviour with moral motivation may also be affected by changes in regulations, economic incentives or other external conditions. For example, a more efficient collection system for source-separated waste may induce people to sharpen the moral claim on their own efforts. Indeed, interviews show that imposing a fee upon people not volunteering in communal work may cause the attendance to drop further

  3. Modeling Regional Economic Impacts of Natural Disasters

    Science.gov (United States)

    Boissonnade, A.; Hallegate, S.; Muir-Wood, R.; Schlumberger, M.; Onur, T.

    2007-05-01

    Common features of natural disasters are intense regional impacts and the need for assessing their economic impacts on the construction sectors. The years 2004 and 2005 were record-setting time for natural disasters with major disasters or catastrophic (Cat) events all around the world with dramatic consequences in human lives and economic losses around the world, affecting developed and developing countries. Although there is a large body of literature on assessing the impact of cat events, there is little available research on the quantification and modeling of the regional economic impact of such events on the cost and length of reconstruction. Current available econometric models have serious limitations because they need detailed information for modeling the complex interactions between the different stakeholders of the economy at a regional level that is generally not available. Also, very little research was performed for quantifying the demand surge, defined as the sudden increase in the cost of repairs due to amplified payments, following a hurricane or a series of hurricane events or other natural disasters. Demand surge is an important component of the overall economic impact of cat events and there is a need to better quantify it. This paper presents results of a research program that started after the 2004 and 2005 U.S. hurricane seasons. A large data set of economic and observed losses resulting from the hurricanes that affected Florida and the Gulf states in the US was collected at county level. This provided us with the basis for assessing the change in repair costs before and after these historical events, to quantify the demand surge (after removing the underlying baseline trends) at several dozens of locations across the areas affected, and to provide information on how the changes in demand surge vary spatially and temporally in affected areas for which the amount of structure losses were reported. A parallel research effort was undertaken for

  4. Learning About Learning in Dynamic Economic Models

    NARCIS (Netherlands)

    Kendrick, D.A.; Amman, H.M.; Tucci, M.P.

    This chapter of the Handbook of Computational Economics is mostly about research on active learning and is confined to discussion of learning in dynamic models in which the systems equations are linear, the criterion function is quadratic and the additive noise terms are Gaussian. Though there is

  5. Modeling Economic Planning for Exhaustible Natural Resources ...

    African Journals Online (AJOL)

    Petroleum economics is a key component of any field development plan (FDP) for crude oil and natural gas fields having finite life. This paper presents an analytical equation to model the relationship between initial speculative fund(s) and investment cost(s) in a project with finite life. We define a utility function for three ...

  6. Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2015-01-01

    Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as competition, or functional traits, such as allometry. To assess the role of disease in mediating mortality risk in quaking aspen (Populus tremuloides), we developed hierarchical Bayesian models for both disease prevalence in live aspen stems and the resulting survival rates of healthy and diseased aspen near the species' southern range limit using 5088 individual trees on 281 United States Forest Service Forest Inventory and Analysis plots in the southwestern United States.

  7. Foreword: "We already know all about aspen"

    Science.gov (United States)

    Dan Binkley

    2001-01-01

    As we developed plans for the symposium on sustaining aspen in western landscapes (held in Grand Junction, Colorado, on June 13-15, 2000), we solicited support from state and federal agencies, universities, and the Rocky Mountain Elk Foundation. The widespread support was very encouraging, and only one agency turned down the opportunity to join in supporting this...

  8. Aspen Winter Conferences on High Energy

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-02-12

    The 2011 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 12 to February 18, 2011. Ninety-four participants from ten countries, and several universities and national labs attended the workshop titled, "New Data From the Energy Frontier." There were 54 formal talks, and a considerable number of informal discussions held during the week. The week's events included a public lecture ("The Hunt for the Elusive Higgs Boson" given by Ben Kilminster from Ohio State University) and attended by 119 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists. The 2011 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was "Indirect and Direct Detection of Dark Matter." It was held from February 6 to February 12, 2011. The 70 participants came from 7 countries and attended 53 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists from other institutions and countries or due to incipient collaborations. In addition, Blas Cabrera of Stanford University gave a public lecture titled "What Makes Up Dark Matter." There were 183 members of the general public in attendance. Before the lecture, 45 people attended the physics cafe to discuss dark matter. This report provides the attendee lists, programs, and announcement posters for each event.

  9. Economic Models as Devices of Policy Change

    DEFF Research Database (Denmark)

    Henriksen, Lasse Folke

    2013-01-01

    Can the emergence of a new policy model be a catalyst for a paradigm shift in the overall interpretative framework of how economic policy is conducted within a society? This paper claims that models are understudied as devices used by actors to induce policy change. This paper explores the role...... the extent to which the performativity approach can help identify macroscopic changes in policy from seemingly microscopic changes in policy models. The concept of performativity is explored as a means of thinking about the constitution of agency directed at policy change. The paper brings this concept...

  10. Mathematical model in economic environmental problems

    Energy Technology Data Exchange (ETDEWEB)

    Nahorski, Z. [Polish Academy of Sciences, Systems Research Inst. (Poland); Ravn, H.F. [Risoe National Lab. (Denmark)

    1996-12-31

    The report contains a review of basic models and mathematical tools used in economic regulation problems. It starts with presentation of basic models of capital accumulation, resource depletion, pollution accumulation, and population growth, as well as construction of utility functions. Then the one-state variable model is discussed in details. The basic mathematical methods used consist of application of the maximum principle and phase plane analysis of the differential equations obtained as the necessary conditions of optimality. A summary of basic results connected with these methods is given in appendices. (au) 13 ills.; 17 refs.

  11. Landscape dynamics in aspen and western juniper woodlands on the Owyhee Plateau, Idaho

    Science.gov (United States)

    Strand, Eva K.

    A century of altered fire regimes has affected the landscape vegetation dynamics in the Intermountain West. Suppression of wildfires has resulted in increases in woody plant cover in these semi-arid ecosystems, which has resulted in land cover changes affecting biogeochemical cycling, landscape composition, and habitat diversity. Recent developments in remote sensing technology, computational power, and a rapid development of analysis techniques have enabled us to quantify such changes at the landscape scale. Wavelet analysis is a powerful image analysis technique that is here applied in a novel fashion to fine scale remote sensing imagery to automatically detect the location and crown diameter of individual western juniper plants (Juniperus occidentalis ssp. occidentalis) expanding into sagebrush (Artemisia spp.) steppe at multiple scales. The produced marked point pattern of historical and current spatial juniper distribution was compared regionally and changes in foliar cover and above ground biomass were estimated across a 330,000 ha area on the Owyhee Plateau, Idaho. The above ground carbon accumulation rate from 1946 to 1998 was estimate to be 3.3 gCm-2yr-1 and 10.0 gCm-2yr -1 employing the wavelet and conventional texture analysis methods, respectively, with an additional 25% rise in belowground carbon accumulation in root stock. This research further demonstrates that estimates of carbon accumulation rates as a result of woody encroachment are highly dependent on the spatial and temporal scales of analysis. Conifer species, western juniper and Douglas-fir (Pseudotsuga menziesii) on the Owyhee Plateau, have further expanded into the biologically important quaking aspen ( Populus tremuloides) habitats resulting in conifer dominance and occasional loss of aspen clones. Classification of remotely sensed imagery combined with spatially explicit modeling of aspen successional stages indicate that, in the absence of management activity, loss of seral aspen stands

  12. Hydro-economic modelling in mining catchments

    Science.gov (United States)

    Ossa Moreno, J. S.; McIntyre, N.; Rivera, D.; Smart, J. C. R.

    2017-12-01

    Hydro-economic models are gaining momentum because of their capacity to model both the physical processes related to water supply, and socio-economic factors determining water demand. This is particularly valuable in the midst of the large uncertainty upon future climate conditions and social trends. Agriculture, urban uses and environmental flows have received a lot of attention from researchers, as these tend to be the main consumers of water in most catchments. Mine water demand, although very important in several small and medium-sized catchments worldwide, has received less attention and only few models have attempted to reproduce its dynamics with other users. This paper describes an on-going project that addresses this gap, by developing a hydro-economic model in the upper Aconcagua River in Chile. This is a mountain catchment with large scale mining and hydro-power users at high altitudes, and irrigation areas in a downstream valley. Relevant obstacles to the model included the lack of input climate data, which is a common feature in several mining areas, the complex hydrological processes in the area and the difficulty of quantifying the value of water used by mines. A semi-distributed model developed within the Water Evaluation and Planning System (WEAP), was calibrated to reproduce water supply, and this was complemented with an analysis of the value of water for mining based on two methods; water markets and an analysis of its production processes. Agriculture and other users were included through methods commonly used in similar models. The outputs help understanding the value of water in the catchment, and its sensitivity to changes in climate variables, market prices, environmental regulations and changes in the production of minerals, crops and energy. The results of the project highlight the importance of merging hydrology and socio-economic calculations in mining regions, in order to better understand trade-offs and cost of opportunity of using

  13. Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

    Directory of Open Access Journals (Sweden)

    Teresa A. Newsome

    2012-01-01

    Full Text Available Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximized R2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. Maximum R2 values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

  14. Economic Modeling of Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Rui Bo

    2013-04-01

    Full Text Available Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES in systems with large-scale wind power generation. The co-optimization of energy and ancillary services markets is implemented in order to analyze the impacts of CAES, not only on energy supply, but also on system operating reserves. Both hourly and 5-minute simulations are considered to capture the economic performance of CAES in the day-ahead (DA and real-time (RT markets. The generalized network flow formulation is used to model the characteristics of CAES in detail. The proposed model is applied on a modified IEEE 24-bus reliability test system. The numerical example shows that besides the economic benefits gained through energy arbitrage in the DA market, CAES can also generate significant profits by providing reserves, compensating for wind forecast errors and intra-hour fluctuation, and participating in the RT market.

  15. Economic model of the US uranium market

    International Nuclear Information System (INIS)

    Owen, A.D.

    1984-01-01

    An economic model of the US uranium market is developed using annual data for the period 1966-81. The model consists of five stochastic equations explaining uranium consumption, forward commitments, mine production, contract prices, and spot prices. A forecasting exercise is also undertaken. By way of essential background information, however, an analysis of current trends in the international uranium market is given, followed by a summary of historical price movements in the US uranium market. A brief discussion on the current state of the US market precedes the statistical analysis. 19 footnotes and references, 3 tables

  16. Economic tour package model using heuristic

    Science.gov (United States)

    Rahman, Syariza Abdul; Benjamin, Aida Mauziah; Bakar, Engku Muhammad Nazri Engku Abu

    2014-07-01

    A tour-package is a prearranged tour that includes products and services such as food, activities, accommodation, and transportation, which are sold at a single price. Since the competitiveness within tourism industry is very high, many of the tour agents try to provide attractive tour-packages in order to meet tourist satisfaction as much as possible. Some of the criteria that are considered by the tourist are the number of places to be visited and the cost of the tour-packages. Previous studies indicate that tourists tend to choose economical tour-packages and aiming to visit as many places as they can cover. Thus, this study proposed tour-package model using heuristic approach. The aim is to find economical tour-packages and at the same time to propose as many places as possible to be visited by tourist in a given geographical area particularly in Langkawi Island. The proposed model considers only one starting point where the tour starts and ends at an identified hotel. This study covers 31 most attractive places in Langkawi Island from various categories of tourist attractions. Besides, the allocation of period for lunch and dinner are included in the proposed itineraries where it covers 11 popular restaurants around Langkawi Island. In developing the itinerary, the proposed heuristic approach considers time window for each site (hotel/restaurant/place) so that it represents real world implementation. We present three itineraries with different time constraints (1-day, 2-day and 3-day tour-package). The aim of economic model is to minimize the tour-package cost as much as possible by considering entrance fee of each visited place. We compare the proposed model with our uneconomic model from our previous study. The uneconomic model has no limitation to the cost with the aim to maximize the number of places to be visited. Comparison between the uneconomic and economic itinerary has shown that the proposed model have successfully achieved the objective that

  17. Modeling and simulation of economic processes

    Directory of Open Access Journals (Sweden)

    Bogdan Brumar

    2010-12-01

    Full Text Available In general, any activity requires a longer action often characterized by a degree of uncertainty, insecurity, in terms of size of the objective pursued. Because of the complexity of real economic systems, the stochastic dependencies between different variables and parameters considered, not all systems can be adequately represented by a model that can be solved by analytical methods and covering all issues for management decision analysis-economic horizon real. Often in such cases, it is considered that the simulation technique is the only alternative available. Using simulation techniques to study real-world systems often requires a laborious work. Making a simulation experiment is a process that takes place in several stages.

  18. The Budget and Economic Outlook: Fiscal Years 2006 to 2015

    Science.gov (United States)

    2005-01-01

    Labor, Bureau of Labor Statistics; Federal Reserve Board; Aspen Publishers, Inc., Blue Chip Economic Indicators (January 10, 2005); Council of...Transmission Biodiesel Fuel Tax Credit African Growth Opportunity Act Depreciation Period for Motor Tracks Dividends of Mutual Funds FUTA Surtax of 0.2...economic forecasts compiled and published monthly by Aspen Publishers, Inc. book depreciation: See depreciation. book profits: Profits calculated using

  19. From Plant Hydraulics to Ecohydrology: a Case Study of Water Limitation in Aspen Forests

    Science.gov (United States)

    Sperry, J.; Venturas, M.; Love, D.; Anderegg, W.; Mackay, D. S.

    2017-12-01

    How dry must it get to threaten a standing forest? We answered this question for aspen stands in Utah with a model that predicts tree gas exchange and water status by optimizing photosynthetic gain vs. hydraulic risk from xylem cavitation. The model was parameterized for 10 aspen stands from various elevations and mountain ranges in the state of Utah, USA. The 2016 growing season was simulated from site-specific micrometeorological data under shallow (0.5 m) vs. deep (2m) root depth scenarios starting at field capacity. The model predicted a water-limiting threshold for each stand, defined as the minimum water input required to maximize stand gas exchange. All but one stand was estimated to be near or above its threshold in 2016. In the majority of stands, spring soil moisture and summer rain fell far short of supplying the threshold requirement. Without additional water, these stands would suffer over 70% loss of tree hydraulic conductance and high mortality risk. These more water-demanding stands were predicted to rely on groundwater for 60-95% of their threshold supply. Groundwater dependence suggests a greater sensitivity to winter precipitation than to growing season conditions. All but the sparsest aspen stands would experience significant mortality risk from a 50% reduction in groundwater input. The aspen test case suggests a wider utility for linking plant hydraulics and hydrology.

  20. Bridging Economic Theory Models and the Cointegrated Vector Autoregressive Model

    DEFF Research Database (Denmark)

    Møller, Niels Framroze

    2008-01-01

    in the economic model implies the econometric concept of strong exogeneity for ß. The economic equilibrium corresponds to the so-called long-run value (Johansen 2005), the comparative statics are captured by the long-run impact matrix, C; and the exogenous variables are the common trends. Also, the adjustment...... parameters of the CVAR are shown to be interpretable in terms of expectations formation, market clearing, nominal rigidities, etc. The general-partial equilibrium distinction is also discussed....

  1. Aspen wood characteristics, properties and uses: a review of recent literature.

    Science.gov (United States)

    Fred M. Lamb

    1967-01-01

    Summarizes information on wood properties and uses of quaking aspen from recent literature. Includes current data on the growth and production of aspen in the Lake States. Outlines additional research needs concerning aspen wood properties and uses.

  2. Forecasting models for national economic planning

    CERN Document Server

    Heesterman, A R G

    1972-01-01

    This book is about the specification of linear econometric models, and for this reason some important related fields have been deliberately omitted. I did not want to discuss the problems of parameter-estimation, at least not in any detail, as there are other books on these problems written by specialized statisticians. This book is about the models them­ selves and macro-economic models in particular. A second related sub­ ject is the policy decision that can be made with the help of a model. While I did write a chapter on policy decisions, I limited myself to some extent because of my views on planning as such. The logical approach to this problem is in terms of mathematical programming, but our models and our ideas about the policies we want are too crude for its effective utilisation. A realistic formulation of the problem should involve non­ linearities in an essential way, the models I consider (and most existing models) are linear. At the present state of econometrics, I do not really believe in suc...

  3. Aspen Characteristics - Plumas National Forest, FRRD [ds375

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Feather River Ranger...

  4. USING GEM - GLOBAL ECONOMIC MODEL IN ACHIEVING A GLOBAL ECONOMIC FORECAST

    Directory of Open Access Journals (Sweden)

    Camelia Madalina Orac

    2013-12-01

    Full Text Available The global economic development model has proved to be insufficiently reliable under the new economic crisis. As a result, the entire theoretical construction about the global economy needs rethinking and reorientation. In this context, it is quite clear that only through effective use of specific techniques and tools of economic-mathematical modeling, statistics, regional analysis and economic forecasting it is possible to obtain an overview of the future economy.

  5. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  6. Simulation of electric power conservation strategies: model of economic evaluation

    International Nuclear Information System (INIS)

    Pinhel, A.C.C.

    1992-01-01

    A methodology for the economic evaluation model for energy conservation programs to be executed by the National Program of Electric Power Conservation is presented. From data as: forecasting of conserved energy, tariffs, energy costs and budget, the model calculates the economic indexes for the programs, allowing the evaluation of economic impacts in the electric sector. (C.G.C.)

  7. Drought causes reduced growth of trembling aspen in western Canada.

    Science.gov (United States)

    Chen, Lei; Huang, Jian-Guo; Alam, Syed Ashraful; Zhai, Lihong; Dawson, Andria; Stadt, Kenneth J; Comeau, Philip G

    2017-07-01

    Adequate and advance knowledge of the response of forest ecosystems to temperature-induced drought is critical for a comprehensive understanding of the impacts of global climate change on forest ecosystem structure and function. Recent massive decline in aspen-dominated forests and an increased aspen mortality in boreal forests have been associated with global warming, but it is still uncertain whether the decline and mortality are driven by drought. We used a series of ring-width chronologies from 40 trembling aspen (Populus tremuloides Michx.) sites along a latitudinal gradient (from 52° to 58°N) in western Canada, in an attempt to clarify the impacts of drought on aspen growth by using Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Results indicated that prolonged and large-scale droughts had a strong negative impact on trembling aspen growth. Furthermore, the spatiotemporal variability of drought indices is useful for explaining the spatial heterogeneity in the radial growth of trembling aspen. Due to ongoing global warming and rising temperatures, it is likely that severer droughts with a higher frequency will occur in western Canada. As trembling aspen is sensitive to drought, we suggest that drought indices could be applied to monitor the potential effects of increased drought stress on aspen trees growth, achieve classification of eco-regions and develop effective mitigation strategies to maintain western Canadian boreal forests. © 2017 John Wiley & Sons Ltd.

  8. Ecology and management of aspen: A Lake States perspective

    Science.gov (United States)

    David T. Cleland; Larry A. Leefers; Donald I. Dickmann

    2001-01-01

    Aspen has been an ecologically important, though relatively minor, component of the Lake States (Michigan, Wisconsin, and Minnesota) forests for millennia. General Land Office records from the 1800s indicate that aspen comprised a small fraction of the region's eastern forests, but was more extensive on the western edge. Then Euro-American settlement in the 1800s...

  9. The effect of aspen wood characteristics and properties on utilization

    Science.gov (United States)

    Kurt H. Mackes; Dennis L. Lynch

    2001-01-01

    This paper reviews characteristics and properties of aspen wood, including anatomical structure and characteristics, moisture and shrinkage properties, weight and specific gravity, mechanical properties, and processing characteristics. Uses of aspen are evaluated: sawn and veneer products, composite panels, pulp, excelsior, post and poles, animal bedding, animal food...

  10. Mycorrhizal fungi of aspen forests: Natural occurrence and potential applications

    Science.gov (United States)

    Cathy L. Cripps

    2001-01-01

    Native mycorrhizal fungi associated with aspen were surveyed on three soil types in the north-central Rocky Mountains. Selected isolates were tested for the ability to enhance aspen seedling growth in vitro. Over 50 species of ectomycorrhizal fungi occur with Populus tremuloides in this region, primarily basidiomycete fungi in the Agaricales. Almost one-third (30%)...

  11. Predation risk and elk-aspen foraging patterns

    Science.gov (United States)

    Clifford A. White; Michael C. Feller

    2001-01-01

    Elk-aspen foraging patterns may be influenced by cover type, distance from roads or trails, the type of user on road or trail (park visitor, human hunter, or predator), and two general states of aspen condition (open-grown or thicket). Pellet group and browse utilization transects in the Canadian Rockies showed that elk were attracted to roads used by park visitors and...

  12. Aspen response to prescribed fire and wild ungulate herbivory

    Science.gov (United States)

    Steve Kilpatrick; Diane Abendroth

    2001-01-01

    Land management agencies in northwest Wyoming have implemented an active prescribed fire program to address historically altered fire regimes, regenerate aspen, and improve overall watershed functions. Treated clones are susceptible to extensive browsing from elk concentrated on supplemental feedgrounds and from wintering moose. Previous attempts at fire-induced aspen...

  13. Predicting Ground Fire Ignition Potential in Aspen Communities

    Science.gov (United States)

    S. G. Otway; E. W. Bork; K. R. Anderson; M. E. Alexander

    2006-01-01

    Fire is one of the key disturbances affecting aspen (Populus tremuloides Michx.) forest ecosystems within western Canadian wildlands, including Elk Island National Park. Prescribed fire use is a tool available to modify aspen forests, yet clearly understanding its potential impact is necessary to successfully manage this disturbance.

  14. Effects of ugulate browsing on aspen regeneration in northwestern Wyoming

    Science.gov (United States)

    Bruce L. Smith; J. Scott Dieni; Roxane L. Rogers; Stanley H. Anderson

    2001-01-01

    Although clearcutting has been demonstrated to be an effective means to regenerate aspen, stand replacement may be retarded under conditions of intense browsing of regeneration, such as that experienced near elk feedgrounds in northwestern Wyoming. We studied the effects of ungulate browsing on regenerating aspen following clearcutting on the National Elk Refuge. Nine...

  15. Dynamics of aspen root biomass and sucker production following fire

    Science.gov (United States)

    Roy A. Renkin; Don G. Despain

    2001-01-01

    Changes in preburn aspen root biomass 8 years following prescribed fire were analyzed for five experimental sites distributed across a moisture gradient. Total root biomass decreased across all sites but was proportionately greater in xeric than mesic sites. Response of post-burn aspen suckers to ungulate browsing varied according to site and treatment. Browsing...

  16. Effects of moisture on aspen-fiber/polypropylene composites

    Science.gov (United States)

    Roger M. Rowell; Sandra E. Lange; Rodney E. Jacobson

    2004-01-01

    Moisture sorption in fiber-thermoplastic composites leads to dimensional instability and biological attack. To determine the pick up of moisture this type of composite, aspen fiber/polypropylene composites were made using several different levels of aspen fiber (30 to 60% by weight) with and without the addition of a compatibilizer (maleic anhydride grafted...

  17. A simple and efficient transient transformation for hybrid aspen (Populus tremula × P. tremuloides

    Directory of Open Access Journals (Sweden)

    Takata Naoki

    2012-08-01

    Full Text Available Abstract Background The genus Populus is accepted as a model system for molecular tree biology. To investigate gene functions in Populus spp. trees, generating stable transgenic lines is the common technique for functional genetic studies. However, a limited number of genes have been targeted due to the lengthy transgenic process. Transient transformation assays complementing stable transformation have significant advantages for rapid in vivo assessment of gene function. The aim of this study is to develop a simple and efficient transient transformation for hybrid aspen and to provide its potential applications for functional genomic approaches. Results We developed an in planta transient transformation assay for young hybrid aspen cuttings using Agrobacterium-mediated vacuum infiltration. The transformation conditions such as the infiltration medium, the presence of a surfactant, the phase of bacterial growth and bacterial density were optimized to achieve a higher transformation efficiency in young aspen leaves. The Agrobacterium infiltration assay successfully transformed various cell types in leaf tissues. Intracellular localization of four aspen genes was confirmed in homologous Populus spp. using fusion constructs with the green fluorescent protein. Protein-protein interaction was detected in transiently co-transformed cells with bimolecular fluorescence complementation technique. In vivo promoter activity was monitored over a few days in aspen cuttings that were transformed with luciferase reporter gene driven by a circadian clock promoter. Conclusions The Agrobacterium infiltration assay developed here is a simple and enhanced throughput method that requires minimum handling and short transgenic process. This method will facilitate functional analyses of Populus genes in a homologous plant system.

  18. International Jobs and Economic Development Impacts (I-JEDI) Model

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    International Jobs and Economic Development Impacts (I-JEDI) is a freely available economic model that estimates gross economic impacts from wind, solar, biomass, and geothermal energy projects. Building on a similar model for the United States, I-JEDI was developed by the National Renewable Energy Laboratory under the U.S. government's Enhancing Capacity for Low Emission Development Strategies (EC-LEDS) program to support partner countries in assessing economic impacts of LEDS actions in the energy sector.

  19. The impact of the British model on economic growth

    Directory of Open Access Journals (Sweden)

    Simon György Jr.

    2007-01-01

    Full Text Available The paper is searching for an answer to the question how the British model affected economic development in its mother country, the United Kingdom. The statistical analysis, models of mathematical economics and econometric investigation make it probable to conclude that there was a substantial difference in success between the Thatcherite and the Blairite economic policies; the latter proved more effective. It is particularly remarkable that the Blairite model, connecting privatization with a successful employment policy, reduced unemployment and social sensitivity, has not only speeded up economic growth but also improved economic equilibrium, curtailing, among others, the budget deficit.

  20. Economic-mathematical methods and models under uncertainty

    CERN Document Server

    Aliyev, A G

    2013-01-01

    Brief Information on Finite-Dimensional Vector Space and its Application in EconomicsBases of Piecewise-Linear Economic-Mathematical Models with Regard to Influence of Unaccounted Factors in Finite-Dimensional Vector SpacePiecewise Linear Economic-Mathematical Models with Regard to Unaccounted Factors Influence in Three-Dimensional Vector SpacePiecewise-Linear Economic-Mathematical Models with Regard to Unaccounted Factors Influence on a PlaneBases of Software for Computer Simulation and Multivariant Prediction of Economic Even at Uncertainty Conditions on the Base of N-Comp

  1. Simulation of IGFC power generation system by Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Rosendahl, Lasse; Sayem, Abu Sadahat

    2010-01-01

    The solid oxide fuel cell (SOFC) is a promising technology for electricity generation. Sulfur free syngas from the gas cleaning unit serves as a fuel for SOFC in IGFC (Integrated gasification Fuel cell) power plant. It converts the chemical energy of the fuel gas directly to electric energy...... efficiency and power with respect to a variety of SOFC inputs. HRSG which is located after the SOFC is also included in current simulation study with various operating parameters. This paper also describes for the IGFC Power Plants, the optimization of the Heat Recovery Steam Generator (HRSG...... and therefore, very high efficiencies can be achieved. The outputs from SOFC can be utilized by HRSG which drives steam turbine for electricity production. The SOFC stack model developed using the process flow sheet simulator Aspen Plus which is of equilibrium type. The results indicate there must be tread off...

  2. Advanced Small Modular Reactor Economics Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Thomas J [ORNL

    2014-10-01

    The US Department of Energy Office of Nuclear Energy’s Advanced Small Modular Reactor (SMR) research and development activities focus on four key areas: Developing assessment methods for evaluating advanced SMR technologies and characteristics; and Developing and testing of materials, fuels and fabrication techniques; and Resolving key regulatory issues identified by US Nuclear Regulatory Commission and industry; and Developing advanced instrumentation and controls and human-machine interfaces. This report focuses on development of assessment methods to evaluate advanced SMR technologies and characteristics. Specifically, this report describes the expansion and application of the economic modeling effort at Oak Ridge National Laboratory. Analysis of the current modeling methods shows that one of the primary concerns for the modeling effort is the handling of uncertainty in cost estimates. Monte Carlo–based methods are commonly used to handle uncertainty, especially when implemented by a stand-alone script within a program such as Python or MATLAB. However, a script-based model requires each potential user to have access to a compiler and an executable capable of handling the script. Making the model accessible to multiple independent analysts is best accomplished by implementing the model in a common computing tool such as Microsoft Excel. Excel is readily available and accessible to most system analysts, but it is not designed for straightforward implementation of a Monte Carlo–based method. Using a Monte Carlo algorithm requires in-spreadsheet scripting and statistical analyses or the use of add-ons such as Crystal Ball. An alternative method uses propagation of error calculations in the existing Excel-based system to estimate system cost uncertainty. This method has the advantage of using Microsoft Excel as is, but it requires the use of simplifying assumptions. These assumptions do not necessarily bring into question the analytical results. In fact, the

  3. REFERENCE MODELS OF ENDOGENOUS ECONOMIC GROWTH

    OpenAIRE

    GEAMĂNU MARINELA

    2012-01-01

    The new endogenous growth theories are a very important research area for shaping the most effective policies and long term sustainable development strategies. Endogenous growth theory has emerged as a reaction to the imperfections of neoclassical theory, by the fact that the economic growth is the endogenous product of an economical system.

  4. Environmental flows in hydro-economic models

    Science.gov (United States)

    Pereau, Jean-Christophe; Pryet, Alexandre

    2018-03-01

    The protection of environmental flows, as a management objective for a regulating agency, needs to be consistent with the aquifer water balance and the degree of resource renewability. A stylized hydro-economic model is used where natural recharge, which sustains environmental flows, is considered both in the aquifer water budget and in the welfare function as ecosystem damage. Groundwater recharge and the associated natural drainage may be neglected for aquifers containing fossil water, where the groundwater is mined. However, when dealing with an aquifer that constitutes a renewable resource, for which recharge is not negligible, natural drainage should explicitly appear in the water budget. In doing so, the optimum path of net extraction rate does not necessarily converge to the recharge rate, but depends on the costs associated with ecosystem damages. The optimal paths and equilibrium values for the water volume and water extraction are analytically derived, and numerical simulations based on the Western La Mancha aquifer (southwest Spain) illustrate the theoretical results of the study.

  5. Economic contract theory tests models of mutualism.

    Science.gov (United States)

    Weyl, E Glen; Frederickson, Megan E; Yu, Douglas W; Pierce, Naomi E

    2010-09-07

    Although mutualisms are common in all ecological communities and have played key roles in the diversification of life, our current understanding of the evolution of cooperation applies mostly to social behavior within a species. A central question is whether mutualisms persist because hosts have evolved costly punishment of cheaters. Here, we use the economic theory of employment contracts to formulate and distinguish between two mechanisms that have been proposed to prevent cheating in host-symbiont mutualisms, partner fidelity feedback (PFF) and host sanctions (HS). Under PFF, positive feedback between host fitness and symbiont fitness is sufficient to prevent cheating; in contrast, HS posits the necessity of costly punishment to maintain mutualism. A coevolutionary model of mutualism finds that HS are unlikely to evolve de novo, and published data on legume-rhizobia and yucca-moth mutualisms are consistent with PFF and not with HS. Thus, in systems considered to be textbook cases of HS, we find poor support for the theory that hosts have evolved to punish cheating symbionts; instead, we show that even horizontally transmitted mutualisms can be stabilized via PFF. PFF theory may place previously underappreciated constraints on the evolution of mutualism and explain why punishment is far from ubiquitous in nature.

  6. An Alternative Theoretical Model for Economic Reforms in Africa ...

    African Journals Online (AJOL)

    This paper offers an alternative model for economic reforms in Africa. It proposes that Africa can still get on the pathway of sustained economic growth if economic reforms can focus on a key variable, namely, the price of non-tradables. Prices of non-tradables are generally less in Africa than in advanced economies, and the ...

  7. Proof of Economic Viability of Blended Learning Business Models

    Science.gov (United States)

    Druhmann, Carsten; Hohenberg, Gregor

    2014-01-01

    The discussion on economically sustainable business models with respect to information technology is lacking in many aspects of proven approaches. In the following contribution the economic viability is valued based on a procedural model for design and evaluation of e-learning business models in the form of a case study. As a case study object a…

  8. Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chung-Jui Tsai; Mark F. Davis; Vincent L. Chiang

    2004-11-10

    As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspen in order to produce trees with reduced lignin content, more reactive lignin structures and increased cellulose content. Transgenic aspen trees with reduced lignin content have already been achieved, prior to the start of this project, by antisense downregulation of a 4-coumarate:coenzyme A ligase gene (Hu et al., 1999 Nature Biotechnol 17: 808- 812). The primary objective of this study was to genetically augment syringyl lignin biosynthesis in these low-lignin trees in order to enhance lignin reactivity during chemical pulping. To accomplish this, both aspen and sweetgum genes encoding coniferaldehyde 5-hydroxylase (Osakabe et al., 1999 PNAS 96: 8955-8960) were targeted for over-expression in wildtype or low-lignin aspen under control of either a constitutive or a xylem-specific promoter. A second objective for this project was to develop reliable and cost-effective methods, such as pyrolysis Molecular Beam Mass Spectrometry and NMR, for rapid evaluation of cell wall chemical components of transgenic wood samples. With these high-throughput techniques, we observed increased syringyl-to-guaiacyl lignin ratios in the transgenic wood samples, regardless of the promoter used or gene origin. Our results confirmed that the coniferaldehyde 5-hydroxylase gene is key to syringyl lignin biosynthesis. The outcomes of this research should be readily applicable to other pulpwood species, and promise to bring direct economic and environmental benefits to the pulp and paper industry.

  9. Genetic diversity in aspen and its relation to arthropod abundance

    Science.gov (United States)

    Zhang, Chunxia; Vornam, Barbara; Volmer, Katharina; Prinz, Kathleen; Kleemann, Frauke; Köhler, Lars; Polle, Andrea; Finkeldey, Reiner

    2015-01-01

    The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen. PMID:25674097

  10. Economic modeling for life extension decision making

    International Nuclear Information System (INIS)

    Farber, M.A.; Harrison, D.L.; Carlson, D.D.

    1986-01-01

    This paper presents a methodology for the economic and financial analysis of nuclear plant life extension under uncertainty and demonstrates its use in a case analysis. While the economic and financial evaluation of life extension does not require new analytical tools, such studies should be based on the following three premises. First, the methodology should examine effects at the level of the company or utility system, because the most important economic implications of life extension relate to the altered generation system expansion plan. Second, it should focus on the implications of uncertainty in order to understand the factors that most affect life extension benefits and identify risk management efforts. Third, the methodology should address multiple objectives, at a minimum, both economic and financial objectives

  11. Techno-Economic Analysis of Magnesium Extraction from Seawater via a Catalyzed Organo-Metathetical Process

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian; Bearden, Mark D.; Fernandez, Carlos A.; Fifield, Leonard S.; Nune, Satish K.; Motkuri, Radha K.; Koech, Philip K.; McGrail, B. Pete

    2018-01-16

    Magnesium (Mg) has many useful applications especially in various Mg alloys which can decrease weight while increasing strength. To increase the affordability and minimize environment consequence, a novel catalyzed organo-metathetical (COMET) process was proposed to extract Mg from seawater aiming to achieve significant reduction in total energy and production cost comparing with the melting salt electrolysis method currently adopted by US Mg LLC. A process flowsheet for a reference COMET process was set-up using Aspen Plus which included five key steps, anhydrous MgCl2 production, transmetallation, dibutyl Mg decomposition, n-BuLi regeneration, and LiCL electrolysis. The energy and production cost and CO2 emission were estimated based on the Aspen modeling using Aspen economic analyzer. Our results showed that it is possible to produce Mg from seawater with a production cost of $2.0/kg-Mg while consuming about 35.3 kWh/kg-Mg and releasing 7.0 kg CO2/kg-Mg. A simplified US Mg manufacturing process was also generated using Aspen and the cost and emission results were estimated for comparison purpose. Under our simulation conditions, the reference COMET process maintain a comparable CO2 emission rate and can save about 40% in production cost and save about 15% energy compared to the simplified US Mg process.

  12. Cloning and characterization of cellulose synthase-like gene, PtrCSLD2 from developing xylem of aspen trees.

    Science.gov (United States)

    Samuga, Anita; Joshi, Chandrashekhar P.

    2004-04-01

    Genetic improvement of cell wall polymer synthesis in forest trees is one of the major goals of forest biotechnology that could possibly impact their end product utilization. Identification of genes involved in cell wall polymer biogenesis is essential for achieving this goal. Among various candidate cell wall-related genes, cellulose synthase-like D (CSLD) genes are intriguing due to their hitherto unknown functions in cell wall polymer synthesis but strong structural similarity with cellulose synthases (CesAs) involved in cellulose deposition. Little is known about CSLD genes from trees. In the present article PtrCSLD2, a first CSLD gene from an economically important tree, aspen (Populus tremuloides) is reported. PtrCSLD2 cDNA was isolated from an aspen xylem cDNA library and encodes a protein that shares 90% similarity with Arabidopsis AtCSLD3 protein involved in root hair tip growth. It is possible that xylem fibers that also grow by intrusive tip growth may need expression of PtrCSLD2 for controlling the length of xylem fibers, a wood quality trait of great economical importance. PtrCSLD2 protein has a N-terminal cysteine-rich putative zinc-binding domain; eight transmembrane domains; alternating conserved and hypervariable domains; and a processive glycosyltransferases signature, D, D, D, QXXRW; all similar to aspen CesA proteins. However, PtrCSLD2 shares only 43-48% overall identity with the known aspen CesAs suggesting its distinct functional role in cell wall polymer synthesis perhaps other than cellulose biosynthesis. Based on Southern analysis, the aspen CSLD gene family consists of at least three genes and this gene copy estimate is supported by phylogenetic analysis of available CSLDs from plants. Moreover, gene expression studies using RT-PCR and in situ mRNA hybridization showed that PtrCSLD2 is expressed at a low level in all aspen tissues examined with a slightly higher expression level in secondary cell wall-enriched aspen xylem as compared to

  13. Optimization of composition and technology for tablets containing aspen bark extract

    Directory of Open Access Journals (Sweden)

    O. I. Onуshkiv

    2015-04-01

    Full Text Available Summary. Influence of quantitativefactorsof basic quality parameters has been investigated for tabletscontainingextractofaspenbark, receivedbydirect pressingmethodand mathematicalplanningof experiment.To set the optimal composition of tablets containingaspen bark extract the proportion ofProsolv 90, Ludiflash and Polyplasdone XL 10 has been studied. The relationship between the studied factors and parameters of tablets’ regression models has been described. As a result tablets containing aspen bark extractwith mentioned above formula match necessary pharmaco-technological parameters of State Pharmacopoeia of Ukraine. Introduction.Peptic and duodenal ulcer are serious problems in modern medicine. According to statistics this disease is found in 12,83 % of the adult population in Ukraine [1]. Among the remedies for treatment and prevention of peptic ulcers we can find herbal medicines that may be used in the treatment of pre-peptic conditions and during an acute period as a means of adjuvant therapy in combination with strong remedies [2]. An antacid, cytoprotective, anti-inflammatory and reparative actions of aspen bark extract were proved by the researches of domestic and foreign scientists [3, 4]. Previously, we researched the mutual influence of excipients on the main indicators of quality of aspen bark extract tablets obtained by direct compression method. Due to these researches the best excipientshave been selected. It is necessary to establish the optimal quantitative proportion of excipients in order to obtain the tablets with suitable parameters that satisfy the requirements of the State Pharmacopoeia of Ukraine (SPU [5, 6]. Rational selection of excipients requires wide range of studies to obtain the optimal composition of the tablets containing aspen bark extract. Using mathematical planning of the experiment gives the possibility to reduce the number of experiments and to obtain the most detailed results of researches about effects

  14. Conversion of bioprocess ethanol to industrial chemical products - Applications of process models for energy-economic assessments

    Science.gov (United States)

    Rohatgi, Naresh K.; Ingham, John D.

    1992-01-01

    An assessment approach for accurate evaluation of bioprocesses for large-scale production of industrial chemicals is presented. Detailed energy-economic assessments of a potential esterification process were performed, where ethanol vapor in the presence of water from a bioreactor is catalytically converted to ethyl acetate. Results show that such processes are likely to become more competitive as the cost of substrates decreases relative to petrolium costs. A commercial ASPEN process simulation provided a reasonably consistent comparison with energy economics calculated using JPL developed software. Detailed evaluations of the sensitivity of production cost to material costs and annual production rates are discussed.

  15. Economic assessment model architecture for AGC/AVLIS selection

    International Nuclear Information System (INIS)

    Hoglund, R.L.

    1984-01-01

    The economic assessment model architecture described provides the flexibility and completeness in economic analysis that the selection between AGC and AVLIS demands. Process models which are technology-specific will provide the first-order responses of process performance and cost to variations in process parameters. The economics models can be used to test the impacts of alternative deployment scenarios for a technology. Enterprise models provide global figures of merit for evaluating the DOE perspective on the uranium enrichment enterprise, and business analysis models compute the financial parameters from the private investor's viewpoint

  16. CAN “THE IDEAL” ECONOMIC MODELS BE CONSIDERED COMPREHENSIBLE ?!

    Directory of Open Access Journals (Sweden)

    A.A. Kuklin

    2006-03-01

    Full Text Available This article opens the cycle of authors’ publications on the questions of theoretical approaches and representations of systems’ economics development. Digression of origin and development of social-economical formations is given. The attempt to consider the transformation of systems’ economics with the consideration of latent dynamic characteristics, to reveal the laws of structural-genetic and functional attribute of changing economy forming was made. Also it is offered to consider the models of systems’ economics transformation and their influence on territorial economic safety of different level.

  17. Modelling and sequential simulation of multi-tubular metallic membrane and techno-economics of a hydrogen production process employing thin-layer membrane reactor

    KAUST Repository

    Shafiee, Alireza

    2016-09-24

    A theoretical model for multi-tubular palladium-based membrane is proposed in this paper and validated against experimental data for two different sized membrane modules that operate at high temperatures. The model is used in a sequential simulation format to describe and analyse pure hydrogen and hydrogen binary mixture separations, and then extended to simulate an industrial scale membrane unit. This model is used as a sub-routine within an ASPEN Plus model to simulate a membrane reactor in a steam reforming hydrogen production plant. A techno-economic analysis is then conducted using the validated model for a plant producing 300 TPD of hydrogen. The plant utilises a thin (2.5 μm) defect-free and selective layer (Pd75Ag25 alloy) membrane reactor. The economic sensitivity analysis results show usefulness in finding the optimum operating condition that achieves minimum hydrogen production cost at break-even point. A hydrogen production cost of 1.98 $/kg is estimated while the cost of the thin-layer selective membrane is found to constitute 29% of total process capital cost. These results indicate the competiveness of this thin-layer membrane process against conventional methods of hydrogen production. © 2016 Hydrogen Energy Publications LLC

  18. Modeling the Economic Behavior of Households within the Context of Development of Economic Thought

    Directory of Open Access Journals (Sweden)

    Ivanov Roman V.

    2017-04-01

    Full Text Available The main purpose of the publication is to study formation of the household economic behavior modeling in the context of development of economic thought and methods of the economic-mathematical modeling. The study was carried out under the assumption that, when studying the development of theoretical and methodological foundations of the economic behavior of households one must take into account not only the history of development of economic theory, but also the transformation of attitudes in other areas of human knowledge, in particular the paradigm shift in scientific thinking. It has been specified that the massive use of mathematical methods in economics is associated with formation of the marginal theory and at the same time – with the proliferation of the marginal analysis. At the present stage, the economic behavior of households is being analyzed in the terms of concepts such as neoclassicism, institutionalism and behaviorism. But by dividing the concepts of «individual» and «household», it can be argued that precisely the institutionalism in conjunction with synergistic approach provide the basis for elaboration of strategies for the economic behavior of households, ensuring their economic security.

  19. Modelling management process of key drivers for economic sustainability in the modern conditions of economic development

    Directory of Open Access Journals (Sweden)

    Pishchulina E.S.

    2017-01-01

    Full Text Available The text is about issues concerning the management of driver for manufacturing enterprise economic sustainability and manufacturing enterprise sustainability assessment as the key aspect of the management of enterprise economic sustainability. The given issues become topical as new requirements for the methods of manufacturing enterprise management in the modern conditions of market economy occur. An economic sustainability model that is considered in the article is an integration of enterprise economic growth, economic balance of external and internal environment and economic sustainability. The method of assessment of economic sustainability of a manufacturing enterprise proposed in the study allows to reveal some weaknesses in the enterprise performance, and untapped reserves, which can be further used to improve the economic sustainability and efficiency of the enterprise. The management of manufacturing enterprise economic sustainability is one of the most important factors of business functioning and development in modern market economy. The relevance of this trend is increasing in accordance with the objective requirements of the growing volumes of production and sale, the increasing complexity of economic relations, changing external environment of an enterprise.

  20. Economic modeling and energy policy planning. [technology transfer, market research

    Science.gov (United States)

    Thompson, R. G.; Schwartz, A., Jr.; Lievano, R. J.; Stone, J. C.

    1974-01-01

    A structural economic model is presented for estimating the demand functions for natural gas and crude oil in industry and in steam electric power generation. Extensions of the model to other commodities are indicated.

  1. The Structured Intuitive Model for Product Line Economics (SIMPLE)

    National Research Council Canada - National Science Library

    Clements, Paul C; McGregor, John D; Cohen, Sholom G

    2005-01-01

    .... This report presents the Structured Intuitive Model of Product Line Economics (SIMPLE), a general-purpose business model that supports the estimation of the costs and benefits in a product line development organization...

  2. ASPEN Plus Simulation of CO2 Recovery Process

    Energy Technology Data Exchange (ETDEWEB)

    White, Charles W. [EG& G Technical Services, Inc., Morgantown, WV (United States)

    2002-09-30

    ASPEN Plus simulations have been created for a CO2 capture process based on adsorption by monoethanolamine (MEA). Three separate simulations were developed, one each for the flue gas scrubbing, recovery, and purification sections of the process. Although intended to work together, each simulation can be used and executed independently. The simulations were designed as template simulations to be added as a component to other more complex simulations. Applications involving simple cycle or hybrid power production processes were targeted. The default block parameters were developed based on a feed stream of raw flue gas of approximately 14 volume percent CO2 with a 90% recovery of the CO2 as liquid. This report presents detailed descriptions of the process sections as well as technical documentation for the ASPEN simulations including the design basis, models employed, key assumptions, design parameters, convergence algorithms, and calculated outputs.

  3. Quantitative predictions of bioconversion of aspen by dilute acid and SPORL pretreatments using a unified combined hydrolysis factor (CHF)

    Science.gov (United States)

    W. Zhu; Carl J. Houtman; J.Y. Zhu; Roland Gleisner; K.F. Chen

    2012-01-01

    A combined hydrolysis factor (CHF) was developed to predict xylan hydrolysis during pretreatments of native aspen (Populus tremuloides) wood chips. A natural extension of previously developed kinetic models allowed us to account for the effect of catalysts by dilute acid and two sulfite pretreatments at different pH values....

  4. Aspen Grupp võitis RKASi / Lemmi Kann

    Index Scriptorium Estoniae

    Kann, Lemmi

    2008-01-01

    Ehitusfirma Aspen Grupp OÜ võitis Tallinna ringkonnakohtus Riigi Kinnisvara AS-i, kes diskvalifitseeris ehitusfirma riigihankelt seaduses olnud maksevõlgnevuse keelu tõttu. Vt. samas: Lahendust ootavad veel kaks kohtuasja

  5. Simulation Models in Economic Higher Education

    OpenAIRE

    Paraschiv Dorel Mihai; Belu Mihaela Gabriela; Popa Ioan

    2013-01-01

    The simulation methods are implemented to develop students' professional skills and competencies in the economic field, making the link between the academic and business environments. The paper presents these methods of simulation in areas such as trade, international business, tourism and banking, applied in the European Program POSDRU/90/2.1/S/63442 project.

  6. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Science.gov (United States)

    Oldén, Anna; Ovaskainen, Otso; Kotiaho, Janne S; Laaka-Lindberg, Sanna; Halme, Panu

    2014-01-01

    Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L.) retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered) and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old-growth forests.

  7. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Directory of Open Access Journals (Sweden)

    Anna Oldén

    Full Text Available Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L. retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old

  8. Simulation of SOFCs based power generation system using Aspen

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-12-01

    Full Text Available This study presents a thermodynamic Aspen simulation model for Solid Oxide Fuel Cells, SOFCs, based power generation system. In the first step, a steady-state SOFCs system model was developed. The model includes the electrochemistry and the diffusion phenomena. The electrochemical model gives good agreement with experimental data in a wide operating range. Then, a parametric study has been conducted to estimate effects of the oxygen to carbon ratio, O/C, on reformer temperature, fuel cell temperature, fuel utilization, overall fuel cell performance, and the results are discussed in this paper. In the second step, a dynamic analysis of SOFCs characteristic has been developed. The aim of dynamic modelling was to find the response of the system against the fuel utilization and the O/C ratio variations. From the simulations, it was concluded that both developed models in the steady and dynamic state were reasonably accurate and can be used for system level optimization studies of the SOFC based power generation system.

  9. Interaction among cervids, fungi, and aspen in northwest Wyoming

    Science.gov (United States)

    John H. Hart; D. L. Hart

    2001-01-01

    Eighty-five 0.02-ha plots in the Gros Ventre River drainage of northwestern Wyoming with high elk usage had 39% fewer aspen stems in 1985 than in 1970. Sixtyfive of these plots were remeasured in 1989 and 53 additional plots established in 1986 on the Hoback River drainage (lower winter elk usage) were remeasured in 1990. Overall mortality (average/year) of aspen stems...

  10. Mathematical model comparing of the multi-level economics systems

    Science.gov (United States)

    Brykalov, S. M.; Kryanev, A. V.

    2017-12-01

    The mathematical model (scheme) of a multi-level comparison of the economic system, characterized by the system of indices, is worked out. In the mathematical model of the multi-level comparison of the economic systems, the indicators of peer review and forecasting of the economic system under consideration can be used. The model can take into account the uncertainty in the estimated values of the parameters or expert estimations. The model uses the multi-criteria approach based on the Pareto solutions.

  11. Long-term monitoring of western aspen--lessons learned.

    Science.gov (United States)

    Strand, E K; Bunting, S C; Starcevich, L A; Nahorniak, M T; Dicus, G; Garrett, L K

    2015-08-01

    Aspen woodland is an important ecosystem in the western United States. Aspen is currently declining in western mountains; stressors include conifer expansion due to fire suppression, drought, disease, heavy wildlife and livestock use, and human development. Forecasting of tree species distributions under future climate scenarios predicts severe losses of western aspen within the next 50 years. As a result, aspen has been selected as one of 14 vital signs for long-term monitoring by the National Park Service Upper Columbia Basin Network. This article describes the development of a monitoring protocol for aspen including inventory mapping, selection of sampling locations, statistical considerations, a method for accounting for spatial dependence, field sampling strategies, and data management. We emphasize the importance of collecting pilot data for use in statistical power analysis and semi-variogram analysis prior to protocol implementation. Given the spatial and temporal variability within aspen stem size classes, we recommend implementing permanent plots that are distributed spatially within and among stands. Because of our careful statistical design, we were able to detect change between sampling periods with desired confidence and power. Engaging a protocol development and implementation team with necessary and complementary knowledge and skills is critical for success. Besides the project leader, we engaged field sampling personnel, GIS specialists, statisticians, and a data management specialist. We underline the importance of frequent communication with park personnel and network coordinators.

  12. Agent-based models in economics a toolkit

    CERN Document Server

    Fagiolo, Giorgio; Gallegati, Mauro; Richiardi, Matteo; Russo, Alberto

    2018-01-01

    In contrast to mainstream economics, complexity theory conceives the economy as a complex system of heterogeneous interacting agents characterised by limited information and bounded rationality. Agent Based Models (ABMs) are the analytical and computational tools developed by the proponents of this emerging methodology. Aimed at students and scholars of contemporary economics, this book includes a comprehensive toolkit for agent-based computational economics, now quickly becoming the new way to study evolving economic systems. Leading scholars in the field explain how ABMs can be applied fruitfully to many real-world economic examples and represent a great advancement over mainstream approaches. The essays discuss the methodological bases of agent-based approaches and demonstrate step-by-step how to build, simulate and analyse ABMs and how to validate their outputs empirically using the data. They also present a wide set of applications of these models to key economic topics, including the business cycle, lab...

  13. Fuel modelling and its economical competitiveness

    International Nuclear Information System (INIS)

    Marino, A.C.; Savino, E.J.

    1996-01-01

    Due to reasons of economical competitiveness, there is at present a strong need in the nuclear industry to improve fuel performance under more demanding operating conditions, such as those resulting from an extended burnup. This requires a good understanding of the properties of fuel rod materials and their in-service performance. As it can be easily foreseen, thermal, mechanical and microstructural irradiation effects are strongly interrelated while the fuel is at reactor operating conditions. (author). 7 refs., 16 figs

  14. Establishment of alleycropped hybrid aspen "Crandon" in central Iowa, USA: effects of topographic position and fertilizer rate on above ground biomass production and allocation

    Science.gov (United States)

    William L. Headlee; Richard B. Hall; Ronald S., Jr. Zalesny

    2013-01-01

    Hybrid poplars have demonstrated high productivity as short rotation woody crops (SRWC) in the Midwest USA, and the hybrid aspen "Crandon" (Populus alba L. × P. grandidenta Michx.) has exhibited particularly promising yields on marginal lands. However, a key obstacle for wider deployment is the lack of economic...

  15. HTGR Application Economic Model Users' Manual

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Gandrik

    2012-01-01

    The High Temperature Gas-Cooled Reactor (HTGR) Application Economic Model was developed at the Idaho National Laboratory for the Next Generation Nuclear Plant Project. The HTGR Application Economic Model calculates either the required selling price of power and/or heat for a given internal rate of return (IRR) or the IRR for power and/or heat being sold at the market price. The user can generate these economic results for a range of reactor outlet temperatures; with and without power cycles, including either a Brayton or Rankine cycle; for the demonstration plant, first of a kind, or nth of a kind project phases; for up to 16 reactor modules; and for module ratings of 200, 350, or 600 MWt. This users manual contains the mathematical models and operating instructions for the HTGR Application Economic Model. Instructions, screenshots, and examples are provided to guide the user through the HTGR Application Economic Model. This model was designed for users who are familiar with the HTGR design and Excel and engineering economics. Modification of the HTGR Application Economic Model should only be performed by users familiar with the HTGR and its applications, Excel, and Visual Basic.

  16. Models of economic geography : dynamics, estimation and policy evaluation

    NARCIS (Netherlands)

    Knaap, Thijs

    2004-01-01

    In this thesis we look at economic geography models from a number of angles. We started by placing the theory in a context of preceding theories, both earlier work on spatial economics and other children of the monopolistic competition ‘revolution.’ Next, we looked at the theoretical properties of

  17. Models of Economic Growth and Development in the Context of ...

    African Journals Online (AJOL)

    The Way Forward for Africa. Lansana Keita* ... to such progress. Key Words: economic growth, economic development, human capital, growth models. Résumé. La littérature économique depuis l'avènement de l'économie moderne a été ..... between the economy's growth rate according to investment and the propensity to ...

  18. Modeling ecological and economic systems with STELLA : Part III

    NARCIS (Netherlands)

    Costanza, Robert; Voinov, Alexey

    2001-01-01

    This special issue contains a group of eight modeling studies covering a range of ecological and economic systems and problems. The models were all developed using Stella®, an icon-based software package specifically designed for dynamic systems modeling. Models included in the special issue were

  19. FISHRENT; Bio-economic simulation and optimisation model

    NARCIS (Netherlands)

    Salz, P.; Buisman, F.C.; Soma, K.; Frost, H.; Accadia, P.; Prellezo, R.

    2011-01-01

    Key findings: The FISHRENT model is a major step forward in bio-economic model-ling, combining features that have not been fully integrated in earlier models: 1- Incorporation of any number of species (or stock) and/or fleets 2- Integration of simulation and optimisation over a period of 25 years 3-

  20. Moving forward socio-economically focused models of deforestation.

    Science.gov (United States)

    Dezécache, Camille; Salles, Jean-Michel; Vieilledent, Ghislain; Hérault, Bruno

    2017-09-01

    Whilst high-resolution spatial variables contribute to a good fit of spatially explicit deforestation models, socio-economic processes are often beyond the scope of these models. Such a low level of interest in the socio-economic dimension of deforestation limits the relevancy of these models for decision-making and may be the cause of their failure to accurately predict observed deforestation trends in the medium term. This study aims to propose a flexible methodology for taking into account multiple drivers of deforestation in tropical forested areas, where the intensity of deforestation is explicitly predicted based on socio-economic variables. By coupling a model of deforestation location based on spatial environmental variables with several sub-models of deforestation intensity based on socio-economic variables, we were able to create a map of predicted deforestation over the period 2001-2014 in French Guiana. This map was compared to a reference map for accuracy assessment, not only at the pixel scale but also over cells ranging from 1 to approximately 600 sq. km. Highly significant relationships were explicitly established between deforestation intensity and several socio-economic variables: population growth, the amount of agricultural subsidies, gold and wood production. Such a precise characterization of socio-economic processes allows to avoid overestimation biases in high deforestation areas, suggesting a better integration of socio-economic processes in the models. Whilst considering deforestation as a purely geographical process contributes to the creation of conservative models unable to effectively assess changes in the socio-economic and political contexts influencing deforestation trends, this explicit characterization of the socio-economic dimension of deforestation is critical for the creation of deforestation scenarios in REDD+ projects. © 2017 John Wiley & Sons Ltd.

  1. Effects of conifers and elk browsing on quaking aspen forests in the central Rocky Mountains, USA

    Science.gov (United States)

    Kaye, Margot W.; Binkley, Dan; Stohlgren, Thomas J.

    2005-01-01

    Elk browsing and conifer species mixing with aspen (Populus tremuloides Michx.) present current challenges to aspen forest management in the western United States. We evaluated the effects of conifers and elk browsing on quaking aspen stands in and near Rocky Mountain National Park using tree rings to reconstruct patterns of aspen establishment, growth, and mortality over the past 120 years. High conifer encroachment and elk browse were both associated with decreased aspen recruitment, with mean recruitment dropping over 30% from pure aspen to mixed stands and over 50% from low-browse to high-browse stands. Maximum aspen recruitment was lower in mixed stands than in pure stands with the same tree basal area. High levels of elk browsing were also associated with a 30% decrease in stand-level growth of aspen. Neither high conifer abundance nor elk browse affected the growth of individual trees or aspen mortality. Aspen establishment was negatively influenced by conifers and elk browsing; however, aspen growth and mortality appeared to be resilient to these two external influences. Overall, these results suggest that long-term preservation of aspen forests could be achieved by enhancing aspen recruitment.

  2. Bifurcations of a class of singular biological economic models

    International Nuclear Information System (INIS)

    Zhang Xue; Zhang Qingling; Zhang Yue

    2009-01-01

    This paper studies systematically a prey-predator singular biological economic model with time delay. It shows that this model exhibits two bifurcation phenomena when the economic profit is zero. One is transcritical bifurcation which changes the stability of the system, and the other is singular induced bifurcation which indicates that zero economic profit brings impulse, i.e., rapid expansion of the population in biological explanation. On the other hand, if the economic profit is positive, at a critical value of bifurcation parameter, the system undergoes a Hopf bifurcation, i.e., the increase of delay destabilizes the system and bifurcates into small amplitude periodic solution. Finally, by using Matlab software, numerical simulations illustrate the effectiveness of the results obtained here. In addition, we study numerically that the system undergoes a saddle-node bifurcation when the bifurcation parameter goes through critical value of positive economic profit.

  3. Response Surface Methodology and Aspen Plus Integration for the Simulation of the Catalytic Steam Reforming of Ethanol

    Directory of Open Access Journals (Sweden)

    Bernay Cifuentes

    2017-01-01

    Full Text Available The steam reforming of ethanol (SRE on a bimetallic RhPt/CeO2 catalyst was evaluated by the integration of Response Surface Methodology (RSM and Aspen Plus (version 9.0, Aspen Tech, Burlington, MA, USA, 2016. First, the effect of the Rh–Pt weight ratio (1:0, 3:1, 1:1, 1:3, and 0:1 on the performance of SRE on RhPt/CeO2 was assessed between 400 to 700 °C with a stoichiometric steam/ethanol molar ratio of 3. RSM enabled modeling of the system and identification of a maximum of 4.2 mol H2/mol EtOH (700 °C with the Rh0.4Pt0.4/CeO2 catalyst. The mathematical models were integrated into Aspen Plus through Excel in order to simulate a process involving SRE, H2 purification, and electricity production in a fuel cell (FC. An energy sensitivity analysis of the process was performed in Aspen Plus, and the information obtained was used to generate new response surfaces. The response surfaces demonstrated that an increase in H2 production requires more energy consumption in the steam reforming of ethanol. However, increasing H2 production rebounds in more energy production in the fuel cell, which increases the overall efficiency of the system. The minimum H2 yield needed to make the system energetically sustainable was identified as 1.2 mol H2/mol EtOH. According to the results of the integration of RSM models into Aspen Plus, the system using Rh0.4Pt0.4/CeO2 can produce a maximum net energy of 742 kJ/mol H2, of which 40% could be converted into electricity in the FC (297 kJ/mol H2 produced. The remaining energy can be recovered as heat.

  4. "Economic microscope": The agent-based model set as an instrument in an economic system research

    Science.gov (United States)

    Berg, D. B.; Zvereva, O. M.; Akenov, Serik

    2017-07-01

    To create a valid model of a social or economic system one must consider a lot of parameters, conditions and restrictions. Systems and, consequently, the corresponding models are proved to be very complicated. The problem of such system model engineering can't be solved only with mathematical methods usage. The decision could be found in computer simulation. Simulation does not reject mathematical methods, mathematical expressions could become the foundation for a computer model. In these materials the set of agent-based computer models is under discussion. All the set models simulate productive agents communications, but every model is geared towards the specific goal, and, thus, has its own algorithm and its own peculiarities. It is shown that computer simulation can discover new features of the agents' behavior that can not be obtained by analytical solvation of mathematical equations and thus plays the role of some kind of economic microscope.

  5. A Discrete Monetary Economic Growth Model with the MIU Approach

    Directory of Open Access Journals (Sweden)

    Wei-Bin Zhang

    2008-01-01

    Full Text Available This paper proposes an alternative approach to economic growth with money. The production side is the same as the Solow model, the Ramsey model, and the Tobin model. But we deal with behavior of consumers differently from the traditional approaches. The model is influenced by the money-in-the-utility (MIU approach in monetary economics. It provides a mechanism of endogenous saving which the Solow model lacks and avoids the assumption of adding up utility over a period of time upon which the Ramsey approach is based.

  6. Paths of economic development: modelling factors of endogenous growth

    OpenAIRE

    Fusari, Angelo

    1994-01-01

    This article sets out a model giving an interpretation of the engine of economic development and growth, and business cycle. Based on a peculiar concept of dynamic competition, the model explains innovation and uncertainty and describes the way equilibrating and disequilibrating processes are intertwined and operate. It also carries out concise application to successive stages of economic development, along with some econometric application, that demonstrates the degree of gene...

  7. Models and relations in economics and econometrics

    DEFF Research Database (Denmark)

    Juselius, Katarina

    1999-01-01

    Based on a money market analysis using the cointegrated VAR model the paper demonstrates some possible pitfalls in macroeconomic inference as a direct consequence of inadequate stochastic model formulation. A number of questions related to concepts such as empirical and theoretical steady-states,...

  8. Models and relations in economics and econometrics

    DEFF Research Database (Denmark)

    Juselius, Katarina

    1999-01-01

    Based on a money market analysis using the cointegrated VAR model the paper demonstrates some possible pitfalls in macroeconomic inference as a direct consequence of inadequate stochastic model formulation. A number of questions related to concepts such as empirical and theoretical steady...

  9. Aspen Global Change Institute Summer Science Sessions

    Energy Technology Data Exchange (ETDEWEB)

    Katzenberger, John; Kaye, Jack A

    2006-10-01

    The Aspen Global Change Institute (AGCI) successfully organized and convened six interdisciplinary meetings over the course of award NNG04GA21G. The topics of the meetings were consistent with a range of issues, goals and objectives as described within the NASA Earth Science Enterprise Strategic Plan and more broadly by the US Global Change Research Program/Our Changing Planet, the more recent Climate Change Program Strategic Plan and the NSF Pathways report. The meetings were chaired by two or more leaders from within the disciplinary focus of each session. 222 scholars for a total of 1097 participants-days were convened under the auspices of this award. The overall goal of each AGCI session is to further the understanding of Earth system science and global environmental change through interdisciplinary dialog. The format and structure of the meetings allows for presentation by each participant, in-depth discussion by the whole group, and smaller working group and synthesis activities. The size of the group is important in terms of the group dynamics and interaction, and the ability for each participant's work to be adequately presented and discussed within the duration of the meeting, while still allowing time for synthesis

  10. Modelling the interaction between flooding events and economic growth

    Directory of Open Access Journals (Sweden)

    J. Grames

    2015-06-01

    Full Text Available Socio-hydrology describes the interaction between the socio-economy and water. Recent models analyze the interplay of community risk-coping culture, flooding damage and economic growth (Di Baldassarre et al., 2013; Viglione et al., 2014. These models descriptively explain the feedbacks between socio-economic development and natural disasters like floods. Contrary to these descriptive models, our approach develops an optimization model, where the intertemporal decision of an economic agent interacts with the hydrological system. In order to build this first economic growth model describing the interaction between the consumption and investment decisions of an economic agent and the occurrence of flooding events, we transform an existing descriptive stochastic model into an optimal deterministic model. The intermediate step is to formulate and simulate a descriptive deterministic model. We develop a periodic water function to approximate the former discrete stochastic time series of rainfall events. Due to the non-autonomous exogenous periodic rainfall function the long-term path of consumption and investment will be periodic.

  11. R.M. Solow Adjusted Model of Economic Growth

    Directory of Open Access Journals (Sweden)

    Ion Gh. Rosca

    2007-05-01

    Full Text Available Besides the models of M. Keynes, R.F. Harrod, E. Domar, D. Romer, Ramsey-Cass-Koopmans etc., the R.M. Solow model is part of the category which characterizes the economic growth. The paper proposes the study of the R.M. Solow adjusted model of economic growth, while the adjustment consisting in the model adaptation to the Romanian economic characteristics. The article is the first one from a three paper series dedicated to the macroeconomic modelling theme, using the R.M. Solow model, such as: “Measurement of the economic growth and extensions of the R.M. Solow adjusted model” and “Evolution scenarios at the Romanian economy level using the R.M. Solow adjusted model”. The analysis part of the model is based on the study of the equilibrium to the continuous case with some interpretations of the discreet one, by using the state diagram. The optimization problem at the economic level is also used; it is built up of a specified number of representative consumers and firms in order to reveal the interaction between these elements.

  12. Modeling PPP Economic Benefits for Lunar ISRU

    Science.gov (United States)

    Blair, B.

    2017-10-01

    A new tool is needed for selecting the PPP strategy that could maximize the rate of lunar commercialization by attracting private capital into the development of critical infrastructure and robust capability. A PPP model under development for NASA-ESO will be described.

  13. A Simple Macro-Economic Model

    Science.gov (United States)

    Carr, J. L.

    1976-01-01

    A simplified model based on assumed linear realtionships between the main variables is used to show how changes in expenditure, tax rate, etc. affect other parts of the national economy in successive periods. See SO 505 143 for ordering information. (Author/ND)

  14. ECONOMIC AND MATHEMATICAL MODELING INNOVATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    D.V. Makarov

    2014-06-01

    Full Text Available The paper presents one of the mathematical tools for modeling innovation processes. With the help of Kondratieff long waves can define innovation cycles. However, complexity of the innovation system implies a qualitative description. The article describes the problems of this area of research.

  15. Economic Models and Algorithms for Distributed Systems

    CERN Document Server

    Neumann, Dirk; Altmann, Jorn; Rana, Omer F

    2009-01-01

    Distributed computing models for sharing resources such as Grids, Peer-to-Peer systems, or voluntary computing are becoming increasingly popular. This book intends to discover fresh avenues of research and amendments to existing technologies, aiming at the successful deployment of commercial distributed systems

  16. Biodiversity: Aspen stands have the lead, but will nonnative species take over?

    Science.gov (United States)

    Geneva W. Chong; Sara E. Simonson; Thomas J. Stohlgren; Mohammed A. Kalkhan

    2001-01-01

    We investigated vascular plant and butterfly diversity in Rocky Mountain National Park. We identified 188 vascular plant species unique to the aspen vegetation type. The slope of the mean species-area curve for the aspen vegetation type was the steepest of the 10 types sampled, thus, an increase in aspen area could have much greater positive impacts on plant species...

  17. Simulation of quaking aspen potential fire behavior in Northern Utah, USA

    Science.gov (United States)

    R. Justin DeRose; A. Joshua Leffler

    2014-01-01

    Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and...

  18. Lichen community change in response to succession in aspen forests of the southern Rocky Mountains

    Science.gov (United States)

    Paul C. Rogers; Ronald J. Ryel

    2008-01-01

    In western North America, quaking aspen (Populus tremuloides) is the most common hardwood in montane landscapes. Fire suppression, grazing and wildlife management practices, and climate patterns of the past century are all potential threats to aspen coverage in this region. If aspen-dependent species are losing habitat, this raises concerns about...

  19. Aspen structure and variability in Rocky Mountain National Park, Colorado, USA

    Science.gov (United States)

    Kaye, Margot W.; Stohlgren, T.J.; Binkley, Dan

    2003-01-01

    Elk, fire and climate have influenced aspen populations in the Rocky Mountains, but mostly subjective studies have characterized these factors. A broad-scale perspective may shed new light on the status of aspen in the region. We collected field measurements of aspen (Populus tremuloides Michx.) patches encountered within 36 randomly located belt transects in 340 km2 of Rocky Mountain National Park, Colorado, to quantify the aspen population. Aspen covered 5.6% of the area in the transects, much more than expected based on previously collected remotely sensed data. The distribution and structure of aspen patches were highly heterogeneous throughout the study area. Of the 123 aspen patches encountered in the 238 ha surveyed, all but one showed signs of elk browsing or had conifer species mixed with the aspen stems. No significant difference occurred in aspen basal area, density, regeneration, browsing of regeneration and patch size, between areas of concentrated elk use (elk winter range) and areas of dispersed elk use (elk summer range). Two-thirds of the aspen patches were mixed with conifer species. We concluded that the population of aspen in our study area is highly variable in structure and that, at a landscape-scale, evidence of elk browsing is widespread but evidence of aspen decline is not.

  20. Plant Community Chemical Composition Influences Trembling Aspen (Populus tremuloides) Intake by Sheep.

    Science.gov (United States)

    Heroy, Kristen Y; St Clair, Samuel B; Burritt, Elizabeth A; Villalba, Juan J

    2017-08-01

    Nutrients and plant secondary compounds in aspen (Populus tremuloides) may interact with nutrients in the surrounding vegetation to influence aspen use by herbivores. Thus, this study aimed to determine aspen intake and preference by sheep in response to supplementary nutrients or plant secondary compounds (PSC) present in aspen trees. Thirty-two lambs were randomly assigned to one of four molasses-based supplementary feeds to a basal diet of tall fescue hay (N = 8) during three experiments. The supplements were as follows: (1) high-protein (60% canola meal), (2) a PSC (6% quebracho tannins), (3) 25% aspen bark, and (4) control (100% molasses). Supplements were fed from 0700 to 0900, then lambs were fed fresh aspen leaves collected from stands containing high (Experiment 1, 2) or low (Experiment 3) concentrations of phenolic glycosides (PG). In Experiment 2, lambs were simultaneously offered aspen, a forb (Lathyrus pauciflorus), and a grass (Bromus inermis) collected from the aspen understory. Animals supplemented with high protein or tannins showed greater intake of aspen leaves than animals supplemented with bark or the control diet (P tannins have a positive effect on protein nutrition and protein aids in PSC detoxification. Overall, animals supplemented with bark showed the lowest aspen intake, suggesting PSC in bark and aspen leaves had additive inhibitory effects on intake. In summary, these results suggest that not only the concentration but also the types and proportions of nutrients and chemical defenses available in the plant community influence aspen use by herbivores.

  1. Trembling aspen response to a mixed-severity wildfire in the Black Hills, South Dakota, USA

    Science.gov (United States)

    Tara L. Keyser; Frederick W. Smith; Wayne D. Shepperd

    2005-01-01

    Trembling aspen (Populus tremuloides Michx.) regeneration dynamics including sprout production, growth, and clone size were measured to determine the effects of fire on small aspen clone persistence following a mixedseverity wildfire in the Black Hills, South Dakota. Four years postfire, 10 small, isolated aspen clones per low and high fire severity...

  2. Economic Modeling of Residual Generation for the Lingayen Gulf Watershed

    Directory of Open Access Journals (Sweden)

    Douglas McGlone

    2000-12-01

    Full Text Available The Philippines is one of four countries involved in the Southeast Asian core project of LOICZ (Land Ocean Interactions in the Coastal Zone which has among its general goals the determination of how changes in human activities affect the fluxes of materials between land, sea, and atmosphere through the coastal zone. The economic component of the Philippine project addresses the question: “How does a change in economic activity affect coastal waters?” Of particular concern is the introduction of anthropogenically-derived residuals (N, P, C, SS into coastal waters. A regional input-output (IO model for Region 1 of the Philippines has been developed to estimate how projected changes in economic activity may affect residual flows into Lingayen Gulf. A residual coefficient matrix, derived from information obtained with a rapid assessment model (RA of residual generation in the Lingayen Gulf watershed, has been incorporated into the IO model. Such a model allows for analysis of various economic scenarios for the region, with projections of residual generation as the output. The resulting changes in residual flows may then serve as inputs to biogeochemical models of Lingayen Gulf. From this process, the impact of various economic scenarios on the water quality of Lingayen Gulf may be ascertained.This paper discusses and compares the RA and IO models of residual generation for the Lingayen Gulf watershed and provides examples of the scenario analysis process.

  3. NEUROBIOLOGY OF ECONOMIC CHOICE: A GOOD-BASED MODEL

    Science.gov (United States)

    Padoa-Schioppa, Camillo

    2012-01-01

    Traditionally the object of economic theory and experimental psychology, economic choice recently became a lively research focus in systems neuroscience. Here I summarize the emerging results and I propose a unifying model of how economic choice might function at the neural level. Economic choice entails comparing options that vary on multiple dimensions. Hence, while choosing, individuals integrate different determinants into a subjective value; decisions are then made by comparing values. According to the good-based model, the values of different goods are computed independently of one another, which implies transitivity. Values are not learned as such, but rather computed at the time of choice. Most importantly, values are compared within the space of goods, independent of the sensori-motor contingencies of choice. Evidence from neurophysiology, imaging and lesion studies indicates that abstract representations of value exist in the orbitofrontal and ventromedial prefrontal cortices. The computation and comparison of values may thus take place within these regions. PMID:21456961

  4. Sustainable economic production quantity models for inventory systems with shortage

    DEFF Research Database (Denmark)

    Taleizadeh, Ata Allah; Soleymanfar, Vahid Reza; Govindan, Kannan

    2018-01-01

    (EPQ). The theoretical sustainable EOQ and EPQ models are basic models that ignore many real-life conditions such as the possibility of stock-out in inventory systems. In this paper, we develop four new sustainable economic production quantity models that consider different shortage situations. To find...... optimal values of inventory system variables, we solve four independent profit maximization problems for four different situations. These proposed models include a basic model in which shortages are not allowed, and when shortages are allowed, the lost sale, full backordering and partial backordering...... models can be selected by operations managers depending on the manufacturer's motivation to improve service levels. We have also proposed an algorithm for determining optimum values of the decision variables for these sustainable economic production quantity models. Finally, the formulated models...

  5. Generic modelling framework for economic analysis of battery systems

    DEFF Research Database (Denmark)

    You, Shi; Rasmussen, Claus Nygaard

    2011-01-01

    Deregulated electricity markets provide opportunities for Battery Systems (BS) to participate in energy arbitrage and ancillary services (regulation, operating reserves, contingency reserves, voltage regulation, power quality etc.). To evaluate the economic viability of BS with different business...... for battery cycle life estimation, since the cycle life plays a central role in the economic analysis of BS. To illustrate the modelling framework, a case study using a Sodium Sulfur Battery (NAS) system with 5-minute regulating service is performed. The economic performances of two dispatch scenarios, a so...

  6. Migration modelling in the New Economic Geography

    OpenAIRE

    Camacho Pérez, Maria del Carmen

    2010-01-01

    The benchmark of this paper is the Fujita and Thisse (2002) core-periphery model, which adds a R&D sector with skilled labor to create new varieties for the modern sector. The number of R&D firms increases not only with the number of existing patents and knowledge spillovers but also with the number of skilled workers who can migrate and choose theregion offering the better lifetime salary.The main objective of the present work is to analyse the long-term consequences of the choice of the mig...

  7. Economic Analysis of Endogenous Growth Model with ICT Capital

    OpenAIRE

    Shoji Katagiri; Hugang Han

    2014-01-01

    This paper clarifies the role of ICT capital in economic growth. Albeit ICT remarkably contributes to economic growth, there are few studies on ICT capital in ICT sector from theoretical point of view. In this paper, production function of ICT which is used as input of intermediate good in final good and ICT sectors is incorporated into our model. In this setting, we analyze the role of ICT on balance growth path and show the possibility of general equilibrium solutions f...

  8. CRISP. Information Security Models and Their Economics

    International Nuclear Information System (INIS)

    Gustavsson, R.; Mellstrand, P.; Tornqvist, B.

    2005-03-01

    The deliverable D1.6 includes background material and specifications of a CRISP Framework on protection of information assets related to power net management and management of business operations related to energy services. During the project it was discovered by the CRISP consortium that the original description of WP 1.6 was not adequate for the project as such. The main insight was that the original emphasis on cost-benefit analysis of security protection measures was to early to address in the project. This issue is of course crucial in itself but requires new models of consequence analysis that still remains to be developed, especially for the new business models we are investigated in the CRISP project. The updated and approved version of the WP1.6 description, together with the also updated WP2.4 focus on Dependable ICT support of Power Grid Operations constitutes an integrated approach towards dependable and secure future utilities and their business processes. This document (D1.6) is a background to deliverable D2.4. Together they provide a dependability and security framework to the three CRISP experiments in WP3

  9. Criteria for comparing economic impact models of tourism

    NARCIS (Netherlands)

    Klijs, J.; Heijman, W.J.M.; Korteweg Maris, D.; Bryon, J.

    2012-01-01

    There are substantial differences between models of the economic impacts of tourism. Not only do the nature and precision of results vary, but data demands, complexity and underlying assumptions also differ. Often, it is not clear whether the models chosen are appropriate for the specific situation

  10. Economic modelling of pork production-marketing chains

    NARCIS (Netherlands)

    Ouden, den M.

    1996-01-01

    The research described in this thesis was focused on the development of economic simulation and optimization computer models to support decision making with respect to pork production- marketing chains. The models include three production stages: pig farrowing, pig fattening and pig slaughtering

  11. Activity-Based Costing Model for Assessing Economic Performance.

    Science.gov (United States)

    DeHayes, Daniel W.; Lovrinic, Joseph G.

    1994-01-01

    An economic model for evaluating the cost performance of academic and administrative programs in higher education is described. Examples from its application at Indiana University-Purdue University Indianapolis are used to illustrate how the model has been used to control costs and reengineer processes. (Author/MSE)

  12. Diagnostics of Expectations of Economic Agents as an Instrument for the Modelling of Economic Cycles

    Directory of Open Access Journals (Sweden)

    Marat Rashitovich Safiullin

    2017-06-01

    Full Text Available The emerging trends of the development of are based on rapid institutional transformations and corresponding progressive forms of value added creation. Therefore, the analysis of these trends demand advanced and evidence-based approaches. Earlier, the processes of economic industrialization, implementation of large-scale solutions, high localization of economic processes were the priority directions for the development. Nowadays, the major proprieties are such strategic focus for the development as the formation and large-scale replication of the local low-concentrated growth points, diversification of business activity, and distribution of technological, institutional, product developments; development of the social parameters of economic growth including those based on the principles of environmental friendliness of business activities, etc. The complexity and multidimensionality of the processes of socio-economic development create a basis for the improvement of the traditional theoretical approaches to modeling and forecasting of economic growth and, respectively, of the cyclic development of the economy. The strengthening of globalization processes as well as the regionalization of the economy, formation of the complex and mobile dynamic structures generating the crisis phenomena make relevant the problem of the modern regulation of the cyclic development of the economy. Its solution is impossible with classical methods of the cyclist theory. The traditional approaches for the modeling of the cyclic development of the economy can lead to a decline in the quality of the predictive models constructed on the basis of extrapolation methods with the application of the scenario forecasts of market and institutional factors which are the drivers of the phase changes of a cycle. The above-mentioned means that the current development of the considered predictive models supposes a number of risks connected with the accuracy of prediction and

  13. Evaluation to the aspen for the air pollution monitoring

    International Nuclear Information System (INIS)

    De La Rosa, D.; Lima, L.; Santana, J.L.; Olivares, S.; Martin, R.; Garcia, M.

    2003-01-01

    Aspen is not often used in bio monitoring programs, but when it is, several interacting and confounding variables have to be considered. Biomass of leaves, and height changes are not easy linked with air pollution, whereas dry weight and leaf abscission are. Visible injury diagnosis and crown thinning are useful records for bio monitoring programs to consider, but skill and understanding of air pollution effects versus seasonal effects are very important. Understanding of actual air pollution symptoms and elemental ratios are especially important. Clonal response and heritability is discuses below, and has to be considered in any bio monitoring program. Above all, integration of aspen response with other key variables is key

  14. Growing Season Conditions Mediate the Dependence of Aspen on Redistributed Snow Under Climate Change.

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Strand, E. K.

    2016-12-01

    Precipitation regimes in many semiarid ecosystems are becoming increasingly dominated by winter rainfall as a result of climate change. Across these regions, snowpack plays a vital role in the distribution and timing of soil moisture availability. Rising temperatures will result in a more uniform distribution of soil moisture, advanced spring phenology, and prolonged growing seasons. Productive and wide ranging tree species like aspen, Populus tremuloides, may experience increased vulnerability to drought and mortality resulting from both reduced snowpack and increased evaporative demand during the growing season. We simulated the net primary production (NPP) of aspen stands spanning the rain:snow transition zone in the Reynolds Creek Critical Zone Observatory (RCCZO) in southwest Idaho, USA. Within the RCCZO, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. The biogeochemical process model Biome-BGC was used to simulate aspen NPP at three stands located directly below snowdrifts that provide melt water late into the spring. After adjusting precipitation inputs to account for the redistribution of snow, we assessed climate change impacts on future aspen productivity. Mid-century (2046-2065) aspen NPP was simulated using temperature projections from a multi-model average under high emission conditions using the Multivariate Adaptive Constructed Analogs (MACA) data set. While climate change simulations indicated over a 20% decrease in annual NPP for some years, NPP rates for other mid-century years remained relatively unchanged due to variations in growing season conditions. Mid-century years with the largest decreases in NPP typically showed increased spring transpiration rates resulting from earlier leaf flush combined with warmer spring conditions. During these years, the onset of drought stress occurred

  15. Physical-Socio-Economic Modeling of Climate Change

    Science.gov (United States)

    Chamberlain, R. G.; Vatan, F.

    2008-12-01

    Because of the global nature of climate change, any assessment of the effects of plans, policies, and response to climate change demands a model that encompasses the entire Earth System, including socio- economic factors. Physics-based climate models of the factors that drive global temperatures, rainfall patterns, and sea level are necessary but not sufficient to guide decision making. Actions taken by farmers, industrialists, environmentalists, politicians, and other policy makers may result in large changes to economic factors, international relations, food production, disease vectors, and beyond. These consequences will not be felt uniformly around the globe or even across a given region. Policy models must comprehend all of these considerations. Combining physics-based models of the Earth's climate and biosphere with societal models of population dynamics, economics, and politics is a grand challenge with high stakes. We propose to leverage our recent advances in modeling and simulation of military stability and reconstruction operations to models that address all these areas of concern. Following over twenty years' experience of successful combat simulation, JPL has started developing Minerva, which will add demographic, economic, political, and media/information models to capabilities that already exist. With these new models, for which we have design concepts, it will be possible to address a very wide range of potential national and international problems that were previously inaccessible. Our climate change model builds on Minerva and expands the geographical horizon from playboxes containing regions and neighborhoods to the entire globe. This system consists of a collection of interacting simulation models that specialize in different aspects of the global situation. They will each contribute to and draw from a pool of shared data. The basic models are: the physical model; the demographic model; the political model; the economic model; and the media

  16. A Model for Assessing the Gender Aspect in Economic Policy

    Directory of Open Access Journals (Sweden)

    Ona Rakauskienė

    2015-06-01

    Full Text Available The purpose of research is to develop a conceptual model for assessing the impact of the gender aspect on economic policy at macro– and microeconomic levels. The research methodology is based on analysing scientific approaches to the gender aspect in economics and gender–responsive budgeting as well as determining the impact of the gender aspect on GDP, foreign trade, the state budget and the labour market. First, the major findings encompass the main idea of a conceptual model proposing that a socio–economic picture of society can be accepted as completed only when, alongside public and private sectors, includes the care/reproductive sector that is dominated by women and creating added value in the form of educated human resources; second, macroeconomics is not neutral in terms of gender equality. Gender asymmetry is manifested not only at the level of microeconomics (labour market and business but also at the level of macroeconomics (GDP, the state budget and foreign trade, which has a negative impact on economic growth and state budget revenues. In this regard, economic decisions, according to the principles of gender equality and in order to achieve gender equality in economics, must be made, as the gender aspect has to be also implemented at the macroeconomic level.

  17. How does economic theory explain the Hubbert peak oil model?

    International Nuclear Information System (INIS)

    Reynes, F.; Okullo, S.; Hofkes, M.

    2010-01-01

    The aim of this paper is to provide an economic foundation for bell shaped oil extraction trajectories, consistent with Hubbert's peak oil model. There are several reasons why it is important to get insight into the economic foundations of peak oil. As production decisions are expected to depend on economic factors, a better comprehension of the economic foundations of oil extraction behaviour is fundamental to predict production and price over the coming years. The investigation made in this paper helps us to get a better understanding of the different mechanisms that may be at work in the case of OPEC and non-OPEC producers. We show that profitability is the main driver behind production plans. Changes in profitability due to divergent trajectories between costs and oil price may give rise to a Hubbert production curve. For this result we do not need to introduce a demand or an exploration effect as is generally assumed in the literature.

  18. Economic model for seaborne oil trade. Master`s thesis

    Energy Technology Data Exchange (ETDEWEB)

    Kian-Wah, H.

    1996-03-01

    This thesis aims to provide some insights as to how oil prices and oil flows might vary with the carrying capacity of the tanker fleet as affected by political events. It provides an econometric analysis of tanker freight rates in the modern era and proposes a mathematical (quadratic) programming economic model that links the crude oil market to the supply elasticity of the world oil tanker fleet based on a competitive economy. The economic model can be considered as a version of the Walras-Cassel general-equilibrium system which possesses an economically meaningful equilibrium solution in terms of oil prices, freight rates and the pattern of oil distribution. The implementation of the model is completed using the General Algebraic Modeling System (GAMS). The study concludes with a scenario study showing how the model could be used to examine the importance of South East Asia`s sealanes in world seaborne oil trade. The model shows the economic vulnerability of oil importing nations, especially Japan, the United States, and Western Europe, to a possible closure of South East Asian sealanes.

  19. Evolutionary modelling of the macro-economic impacts of catastrophic flood events

    NARCIS (Netherlands)

    Safarzynska, K.E.; Brouwer, R.; Hofkes, M.

    2013-01-01

    This paper examines the possible contribution of evolutionary economics to macro-economic modelling of flood impacts to provide guidance for future economic risk modelling. Most macro-economic models start from a neoclassical economic perspective and focus on equilibrium outcomes, either in a static

  20. ON SKEW-NORMAL MODEL FOR ECONOMICALLY ACTIVE POPULATION

    Directory of Open Access Journals (Sweden)

    OLOSUNDE AKINLOLU A

    2011-04-01

    Full Text Available The literature related to skew-symmetric distribution have grown rapidly in recent years but at the moment no publication on its applications concerning the description of economically active data with this type of probability models. In this paper, we provided an extension to this skew-normal distribution, which is also part of the family of skewed class of normal but with additional shape parameters δ. Some properties of this distribution are presented and finally, we considered fitting it to economically active population data. The model exhibited a better behaviour when compared to normal and skew normal distributions.

  1. Renewable hydrocarbon fuels from hydrothermal liquefaction: A techno-economic analysis

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Hansen, Nick Høy; Pérez, Oscar Miralles

    2018-01-01

    This study demonstrates the economic feasibility of producing renewable transportation drop-in fuels from lignocellulosic biomass through hydrothermal liquefaction and upgrading. An Aspen Plus® process model is developed based on extensive experimental data to document a techno-economic assessment...... by thermal cracking and hydroprocessing. Results show that a minimum fuel selling price (MFSP) of 1.14 $ per liter of gasoline equivalent (LGE) can be obtained. In Scenario II, only wood is used as feedstock, which reduces the MFSP to 0.82 $/LGE. Scenario III is also based on a pure wood feedstock...

  2. ONTOLOGICAL MODEL OF STRATEGIC ECONOMIC SECURITY OF ENTERPRISE

    Directory of Open Access Journals (Sweden)

    L. A. Zaporozhtseva

    2014-01-01

    Full Text Available Article explains the necessity the application of the ontological approach to modeling the strategic economic security in the formalization of the basic categories of domain company recognized its benefits. Among the advantages of the model distinguishes its versatility and ability to describe various aspects of strategic security - the system strategies and goals of the organization and business processes; possibility of its use at different levels of detail - from the top-level description of the basic categories of management, to design-level analytic applications; as well as the adaptability of the model, with depth on particular aspects determined by practical necessity and not regulated methodology. The model integrates various aspects of the concept of enterprise architecture and organizes conceptual apparatus. Ontological model easy to understand and adjust as business architects and specialists in designing systems of economic security and offers many categories of verbal representation of the domain of the enterprise. Proved the feasibility of using process-functional approach in providing strategic economic security, according to which the components of such a security company proposed as business processes, finance, staff and contractors. The article presents the author's ontological model of strategic economic security, including endangered sites, the presence of factors that threaten the security of the object and the subject of providing security. Further, it is proved that in the subjects of security impact on the object using the tools, measures and activities within the strategy formed the mechanism is implemented managerial decisions to strengthen the strategic economic security. The process of diagnosis, detection, identification of threats of economic security, and the development of enterprise development strategies, taking into account its level of economic security must be under the constant supervision of the process of

  3. Using glyphosate herbicide in converting aspen to conifers.

    Science.gov (United States)

    Donald A. Perala

    1985-01-01

    Glyphosate at 1.5 to 2.0 lbs. Per acre active ingredient will control aspen suckers, shrubs, and herbs when applied during August to early September. There appears to be some intersite variability in the efficacy of the herbicide.

  4. Historical patterns in lichen communities of montane quaking aspen forests

    Science.gov (United States)

    Paul C. Rogers; Dale L. Bartos; Ronald J. Ryel

    2011-01-01

    Climate shifts and resource exploitation in Rocky Mountain forests have caused profound changes in quaking aspen (Populus tremuloides Michx.) structure and function since Euro-American settlement. It therefore seems likely that commensurate shifts in dependent epiphytes would follow major ecological transitions. In the current study, we merge several lines of inquiry...

  5. Defining Excellence: Lessons from the 2013 Aspen Prize Finalists

    Science.gov (United States)

    Aspen Institute, 2013

    2013-01-01

    In many respects, one couldn't find a group of 10 schools more diverse than the finalists for the 2013 Aspen Prize for Community College Excellence. One community college serves 1,500 students, another 56,000. There are institutions devoted primarily--even solely--to technical degrees, and ones devoted mainly to preparing students for further…

  6. The 2013 Aspen Prize for Community College Excellence

    Science.gov (United States)

    Perlstein, Linda

    2013-01-01

    For millions of Americans, community colleges provide an essential pathway to well-paying jobs and continuing higher education. The Aspen Prize for Community College Excellence honors those institutions that strive for and achieve exceptional levels of success for all students, while they are in college and after they graduate. Community colleges…

  7. Preliminary study on flakeboard panels made from aspen slash wood

    Science.gov (United States)

    Yan Yu; Alan Rudie; Zhiyong Cai

    2010-01-01

    The disposal of forest-thinning residue is one of the major problems for sustainable forest management. The purpose of this study was to investigate the technical possibility of utilizing aspen logging slash wood with a diameter ranging from 50 to 76 mm for flakeboard production. Influences of weight ratio between slash wood and commercial flakes on the selected...

  8. Aspen ecosystem properties in the Upper Great Lakes.

    Science.gov (United States)

    David H. Alban; Donald A. Perala; Martin F. Jurgensen; Michael E. Ostry; John R. Probst

    1991-01-01

    Describes four ecosystems in Minnesota and Michigan comprised of mature aspen stands on a range of soils from sandy to clay. The ecosystems are part of a long-term study of the effects of harvesting and species conversion on ecosystem properties. Presents data on geology, weather, soils, vegetation, litterfall, nitrogen dynamics, insects, disease, and wildlife.

  9. Timber resource of Minnesota's Aspen-Birch Unit, 1977.

    Science.gov (United States)

    John S. Jr. Spencer; Arnold J. Ostrom

    1979-01-01

    The fourth inventory of Minnesota's Aspen-Birch Unit shows solid gains in growing-stock and sawtimber volumes between 1962 and 1977, but a 13% decline in commercial forest area. This report gives statistical highlights and contains detailed tables of forest area a well as timber volume, growth, mortality, ownership, and use.

  10. Aspen fencing in northern Arizona: A 15-year perspective

    Science.gov (United States)

    James M. Rolf

    2001-01-01

    Aspen clearcuts in the 1960s and 1970s on the Peaks Ranger District of the Coconino National Forest in northern Arizona failed to regenerate successfully because of browsing primarily by elk. Since 1985, over 400 acres have been successfully regenerated using fencing of various designs to exclude elk. The expense and visual impact of establishing and maintaining over...

  11. Economic decision making and the application of nonparametric prediction models

    Science.gov (United States)

    Attanasi, E.D.; Coburn, T.C.; Freeman, P.A.

    2008-01-01

    Sustained increases in energy prices have focused attention on gas resources in low-permeability shale or in coals that were previously considered economically marginal. Daily well deliverability is often relatively small, although the estimates of the total volumes of recoverable resources in these settings are often large. Planning and development decisions for extraction of such resources must be areawide because profitable extraction requires optimization of scale economies to minimize costs and reduce risk. For an individual firm, the decision to enter such plays depends on reconnaissance-level estimates of regional recoverable resources and on cost estimates to develop untested areas. This paper shows how simple nonparametric local regression models, used to predict technically recoverable resources at untested sites, can be combined with economic models to compute regional-scale cost functions. The context of the worked example is the Devonian Antrim-shale gas play in the Michigan basin. One finding relates to selection of the resource prediction model to be used with economic models. Models chosen because they can best predict aggregate volume over larger areas (many hundreds of sites) smooth out granularity in the distribution of predicted volumes at individual sites. This loss of detail affects the representation of economic cost functions and may affect economic decisions. Second, because some analysts consider unconventional resources to be ubiquitous, the selection and order of specific drilling sites may, in practice, be determined arbitrarily by extraneous factors. The analysis shows a 15-20% gain in gas volume when these simple models are applied to order drilling prospects strategically rather than to choose drilling locations randomly. Copyright ?? 2008 Society of Petroleum Engineers.

  12. Models of Russia's Participation in Regional Economic Integration

    Directory of Open Access Journals (Sweden)

    Darya I. Ushkalova

    2014-01-01

    Full Text Available The article analyses models and mechanisms of Russia's participation in integration processes in Post-Soviet space in recent years. The article examines the model of integration of Customs Union Common Economic Space Eurasian Economic Union and particular mechanisms of its realization. It also examines key challenges to further development of integration in the frameworks of Eurasian Economic Union including exhausting of short-term and medium-term integration effects against a background of low level of economic cooperation and the lack of effective mechanism of interest coordination and decisionmaking similar to qualified majority. It concludes that deterioration of mutual trade dynamics in Customs Union is determined by fundamental factors, first of all, exhausting of medium-term integration effects which lead to extension of mutual trade immediately after Customs Union creation but do not change its qualitative characteristics in long-term outlook. The author shows an absence of significant long-term integration effects which were based on increase of domestic market capacity due to a modification of economic structure. It is founded that appearance of such long-term integration effects is possible only in the context of coalescence of national economies at the microlevel based on development of system of communications between enterprises including intrasectoral industrial cooperation. The article also analyses results of realization of Russia's strategy of interaction with states beyond Eurasian Economic Union based on open regionalism concept. The paper presents recommendation on perfection of tools of integration in and outside Eurasian Economic Union. In particular, creation of system of decentralized organizations is proposed, for the implementation of specific cooperation projects in selected areas, taking into account the multiplier effect of such a "point-aimed" action/

  13. Review of whole-farm economic modelling for irrigation farming ...

    African Journals Online (AJOL)

    The main objective of this paper is to review the progress that has been made in South Africa with respect to whole-farm economic modelling over the past 2 decades. Farming systems are complex and careful consideration to the stochastic dynamic nature of irrigation farming processes and their linkages with the larger ...

  14. The economic production lot size model with several production rates

    DEFF Research Database (Denmark)

    Larsen, Christian

    We study an extension of the economic production lot size model, where more than one production rate can be used during a cycle. The production rates and their corresponding runtimes are decision variables. We decompose the problem into two subproblems. First, we show that all production rates...

  15. Micro-economic panel data models for Dutch dairy farming

    NARCIS (Netherlands)

    Ooms, D.L.

    2007-01-01

    Keywords:micro-economic models, panel data, GMM, CAP reform, dairy farmingIn The Netherlands, thedairy sector is the largest agricultural sub-sector based on both gross production value and number of

  16. Bio-economic household modelling for agricultural intensification

    NARCIS (Netherlands)

    Kruseman, G.

    2000-01-01

    This study contributes to the quest for sustainable agricultural intensification through the development of a quantitative bio-economic modelling framework that allows assessment of new technology and policy measures in terms of household welfare and sustainability indicators. The main aim

  17. An Economic Model of Workplace Mobbing in Academe

    Science.gov (United States)

    Faria, Joao Ricardo; Mixon, Franklin G., Jr.; Salter, Sean P.

    2012-01-01

    Workplace bullying or mobbing can be defined as the infliction of various forms of abuse (e.g., verbal, emotional, psychological) against a colleague or subordinate by one or more other members of a workplace. Even in the presence of academic tenure, workplace mobbing remains a prevalent issue in academe. This study develops an economic model that…

  18. Using STELLA Simulation Models to Teach Natural Resource Economics

    Science.gov (United States)

    Dissanayake, Sahan T. M.

    2016-01-01

    In this article, the author discusses how graphical simulation models created using STELLA software can be used to present natural resource systems in an intuitive way in undergraduate natural resource economics classes based on his experiences at a leading research university, a state university, and a leading liberal arts college in the United…

  19. Real-Time Optimization for Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Edlund, Kristian; Frison, Gianluca

    2012-01-01

    In this paper, we develop an efficient homogeneous and self-dual interior-point method for the linear programs arising in economic model predictive control. To exploit structure in the optimization problems, the algorithm employs a highly specialized Riccati iteration procedure. Simulations show...

  20. Electric vehicle charge planning using Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus; Poulsen, Niels K.; Madsen, Henrik

    2012-01-01

    Economic Model Predictive Control (MPC) is very well suited for controlling smart energy systems since electricity price and demand forecasts are easily integrated in the controller. Electric vehicles (EVs) are expected to play a large role in the future Smart Grid. They are expected to provide...

  1. R.M. Solow Adjusted Model of Economic Growth

    Directory of Open Access Journals (Sweden)

    Ion Gh. Rosca

    2007-05-01

    The analysis part of the model is based on the study of the equilibrium to the continuous case with some interpretations of the discreet one, by using the state diagram. The optimization problem at the economic level is also used; it is built up of a specified number of representative consumers and firms in order to reveal the interaction between these elements.

  2. Student Migration to Online Education: An Economic Model

    Science.gov (United States)

    Eisenhauer, Joseph G.

    2013-01-01

    The popularity of distance education has increasingly led universities to consider expanding their online offerings. Remarkably few financial models have been presented for online courses, however, and fewer still have investigated the economic consequences of the migration, or cross-over, of students from traditional classes within the…

  3. Neural networks in economic modelling : An empirical study

    NARCIS (Netherlands)

    Verkooijen, W.J.H.

    1996-01-01

    This dissertation addresses the statistical aspects of neural networks and their usability for solving problems in economics and finance. Neural networks are discussed in a framework of modelling which is generally accepted in econometrics. Within this framework a neural network is regarded as a

  4. A Markov decision model for optimising economic production lot size ...

    African Journals Online (AJOL)

    Abstract. Traditional approaches towards determining the economic production lot (EPL) size in man- ufacturing applications assume deterministic demand, often at a constant rate. In this paper, an optimisation model is developed for determining the EPL size that minimises production and inventory costs of a periodic ...

  5. Energy technologies and energy efficiency in economic modelling

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik

    1998-01-01

    This paper discusses different approaches to incorporating energy technologies and technological development in energy-economic models. Technological development is a very important issue in long-term energy demand projections and in environmental analyses. Different assumptions on technological...... technological development. This paper examines the effect on aggregate energy efficiency of using technological models to describe a number of specific technologies and of incorporating these models in an economic model. Different effects from the technology representation are illustrated. Vintage effects...... illustrates the dependence of average efficiencies and productivity on capacity utilisation rates. In the long run regulation induced by environmental policies are also very important for the improvement of aggregate energy efficiency in the energy supply sector. A Danish policy to increase the share...

  6. Accounting for household heterogeneity in general equilibrium economic growth models

    International Nuclear Information System (INIS)

    Melnikov, N.B.; O'Neill, B.C.; Dalton, M.G.

    2012-01-01

    We describe and evaluate a new method of aggregating heterogeneous households that allows for the representation of changing demographic composition in a multi-sector economic growth model. The method is based on a utility and labor supply calibration that takes into account time variations in demographic characteristics of the population. We test the method using the Population-Environment-Technology (PET) model by comparing energy and emissions projections employing the aggregate representation of households to projections representing different household types explicitly. Results show that the difference between the two approaches in terms of total demand for energy and consumption goods is negligible for a wide range of model parameters. Our approach allows the effects of population aging, urbanization, and other forms of compositional change on energy demand and CO 2 emissions to be estimated and compared in a computationally manageable manner using a representative household under assumptions and functional forms that are standard in economic growth models.

  7. Control of chaotic dynamics in an OLG economic model

    International Nuclear Information System (INIS)

    Mendes, Diana A; Mendes, Vivaldo

    2005-01-01

    This paper deals with the control of chaotic economic motion. We show that very complicated dynamics arising, e.g., from an overlapping generations model (OLG) with production and an endogenous intertemporal decision between labour and leisure, which produces chaos, can in fact be controlled with relative simplicity. The aperiodic and very complicated motion that stems from this model can be subject to control by small perturbations in its parameters and turned into a stable steady state or into a regular cycle. Therefore, the system can be controlled without changing of its original properties. To perform the control of the totally unstable equilibrium (both eigenvalues with modulus greater than unity) in this economic model we apply the pole-placement technique, developed by Romeiras, Grebogi, Ott and Dayawansa (1992). The application of control methods to chaotic economic dynamics may raise serious reservations, at least on mathematical and logical grounds, to some recent views on economics which have argued that economic policy becomes useless in the presence of chaotic motion (and thus, that the performance of the economic system cannot be improved by public intervention, i.e., that the amplitude of cycles can not be controlled or reduced). In fact, the fine tuning of the system (that is, the control) can be performed without having to rely only on infinitesimal accuracy in the perturbation to the system, because the control can be performed with larger or smaller perturbations, but neither too large (because these would lead to a different fixed point of the system, therefore modifying its original nature), nor too small because the control becomes too inefficient

  8. Orbital Express mission operations planning and resource management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel

    2008-04-01

    As satellite equipment and mission operations become more costly, the drive to keep working equipment running with less labor-power rises. Demonstrating the feasibility of autonomous satellite servicing was the main goal behind the Orbital Express (OE) mission. Like a tow-truck delivering gas to a car on the road, the "servicing" satellite of OE had to find the "client" from several kilometers away, connect directly to the client, and transfer fluid (or a battery) autonomously, while on earth-orbit. The mission met 100% of its success criteria, and proved that autonomous satellite servicing is now a reality for space operations. Planning the satellite mission operations for OE required the ability to create a plan which could be executed autonomously over variable conditions. As the constraints for execution could change weekly, daily, and even hourly, the tools used create the mission execution plans needed to be flexible and adaptable to many different kinds of changes. At the same time, the hard constraints of the plans needed to be maintained and satisfied. The Automated Scheduling and Planning Environment (ASPEN) tool, developed at the Jet Propulsion Laboratory, was used to create the schedule of events in each daily plan for the two satellites of the OE mission. This paper presents an introduction to the ASPEN tool, an overview of the constraints of the OE domain, the variable conditions that were presented within the mission, and the solution to operations that ASPEN provided. ASPEN has been used in several other domains, including research rovers, Deep Space Network scheduling research, and in flight operations for the NASA's Earth Observing One mission's EO1 satellite. Related work is discussed, as are the future of ASPEN and the future of autonomous satellite servicing.

  9. A Reformulation of Normative Economics for Models with Endogenous Preferences

    OpenAIRE

    Vipul Bhatt; Masao Ogaki; Yuichi Yaguchi

    2014-01-01

    This paper proposes a framework to balance considerations of welfarism and virtue ethics in the normative analysis of economic models with endogenous preferences. We introduce the moral evaluation function (MEF), which ranks alternatives based purely on virtue ethics, and define the social objective function (SOF), which combines the Social Welfare Function (SWF) and the MEF. In a model of intergenerational altruism with endogenous time preference, using numerical simulations we show that max...

  10. A Reformulation of Normative Economics for Models with Endogenous

    OpenAIRE

    Bhatt, Vipul; Ogaki, Masao; Yaguchi, Yuichi

    2015-01-01

    This paper proposes a framework to balance considerations of welfarism and virtue ethics in the normative analysis of economic models with endogenous preferences. We introduce the moral evaluation function (MEF), which ranks alternatives based purely on virtue ethics, and define the social objective function (SOF), which combines the Social Welfare Function (SWF) and the MEF. In a model of intergenerational altruism with endogenous time preference, using numerical simulations we show that max...

  11. Economic MPC based on LPV model for thermostatically controlled loads

    DEFF Research Database (Denmark)

    Zemtsov, Nikita; Hlava, Jaroslav; Frantsuzova, Galina

    2017-01-01

    Rapid increase of the renewable energy share in electricity production requires optimization and flexibility of the power consumption side. Thermostatically controlled loads (TCLs) have a large potential for regulation service provision. Economic model predictive control (MPC) is an advanced....... As a case study, we present control system that minimizes operational cost of swimming pool heating system, where parameters of the model depend on the weather forecast. Simulation results demonstrate that the proposed method is able to deal with this kind of systems....

  12. Aspen Plus Simulation of Saponification of Ethyl Acetate in the Presence of Sodium Hydroxide in a Plug Flow Reactor

    OpenAIRE

    U. P. L. Wijayarathne; K. C. Wasalathilake

    2014-01-01

    This work presents the modelling and simulation of saponification of ethyl acetate in the presence of sodium hydroxide in a plug flow reactor using Aspen Plus simulation software. Plug flow reactors are widely used in the industry due to the non-mixing property. The use of plug flow reactors becomes significant when there is a need for continuous large scale reaction or fast reaction. Plug flow reactors have a high volumetric unit conversion as the occurrence for side rea...

  13. A review of mathematical models in economic environmental problems

    DEFF Research Database (Denmark)

    Nahorski, Z.; Ravn, H.F.

    2000-01-01

    The paper presents a review of mathematical models used,in economic analysis of environmental problems. This area of research combines macroeconomic models of growth, as dependent on capital, labour, resources, etc., with environmental models describing such phenomena like natural resources...... exhaustion or pollution accumulation and degradation. In simpler cases the models can be treated analytically and the utility function can be optimized using, e.g., such tools as the maximum principle. In more complicated cases calculation of the optimal environmental policies requires a computer solution....

  14. Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performance

    Science.gov (United States)

    Leanne M. Vigue; Richard L. Lindroth

    2010-01-01

    Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as...

  15. Modeling utility-scale wind power plants, part 1: Economics

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, M.

    2000-06-29

    As the worldwide use of wind turbine generators continues to increase in utility-scale applications, it will become increasingly important to assess the economic and reliability impact of these intermittent resources. Although the utility industry in the United States appears to be moving towards a restructured environment, basic economic and reliability issues will continue to be relevant to companies involved with electricity generation. This paper is the first of two that address modeling approaches and results obtained in several case studies and research projects at the National Renewable Energy Laboratory (NREL). This first paper addresses the basic economic issues associated with electricity production from several generators that include large-scale wind power plants. An important part of this discussion is the role of unit commitment and economic dispatch in production-cost models. This paper includes overviews and comparisons of the prevalent production-cost modeling met hods, including several case studies applied to a variety of electric utilities. The second paper discusses various methods of assessing capacity credit and results from several reliability-based studies performed at NREL.

  16. Economics of extreme weather events: Terminology and regional impact models

    Directory of Open Access Journals (Sweden)

    Malte Jahn

    2015-12-01

    Full Text Available Impacts of extreme weather events are relevant for regional (in the sense of subnational economies and in particular cities in many aspects. Cities are the cores of economic activity and the amount of people and assets endangered by extreme weather events is large, even under the current climate. A changing climate with changing extreme weather patterns and the process of urbanization will make the whole issue even more relevant in the future. In this paper, definitions and terminology in the field of extreme weather events are discussed. Possible regional impacts of extreme weather events are collected, focusing on European cities. The human contributions to those impacts are emphasized. Furthermore, methodological aspects of economic impact assessment are discussed along a temporal and a sectoral dimension. Finally, common economic impact models are compared, analyzing their strengths and weaknesses.

  17. [Human resources planning: the use of demographic-economic models].

    Science.gov (United States)

    Daubon, R E

    1980-01-01

    This article provides an overview of the evolution of employment at different stages of economic development and describes the employment situation in developing countries, suggesting future trends and means of improvement. The lack of authentic development is reflected in the problem of employment of both natural and human resources in Third World countries. Their occupational structures may be examined in 2 periods, 1 in which a certain pretransitional equilibrium was still observed, and the other following the beginning of industrialization. With increased population growth and the application of development strategies favoring urban areas and manufacturing, a series of imbalances were introduced which had as 1 consequence an ever widening income gap between rural areas, cities, and developed countries. Rural stagnation and population pressure ultimately led to massive urban migration in many areas, swelling the cities and creating an "informal sector" of underemployed persons in marginal activities of low productivity. By 2050, the world labor force will have increased from its present 1.7 billion workers to 3.8 billion, of which only 660 million will be in presently developed countries. Each country must plan the best use of its human resources, and must include employment planning in overall development planning. The development of economic-demographic models, adapted to the context of each country, can be a valuable tool in planning. Various types of economic-demographic models and their uses are described and differentiated. Economic-demographic models of employment have 3 main parts, demography, economy, and training. Their use in the analysis of the impact of specific variables on employment, of policies, and of general strategies is described. Finally, the characteristics and uses of MODEMP, an economic-demographic model created for analysis of labor force and employment problems in Peru, are described.

  18. Assisted migration to address climate change: recommendations for aspen reforestation in western Canada.

    Science.gov (United States)

    Gray, Laura K; Gylander, Tim; Mbogga, Michael S; Chen, Pei-Yu; Hamann, Andreas

    2011-07-01

    Human-aided movement of species populations in large-scale reforestation programs could be a potent and cost-effective climate change adaptation strategy. Such large-scale management interventions, however, tend to entail the risks of unintended consequences, and we propose that three conditions should be met before implementing assisted migration in reforestation programs: (1) evidence of a climate-related adaptational lag, (2) observed biological impacts, and (3) robust model projections to target assisted migration efforts. In a case study of aspen (Populus tremuloides Michaux.) we use reciprocal transplant experiments to study adaptation of tree populations to local environments. Second, we monitor natural aspen populations using the MODIS enhanced vegetation index as a proxy for forest health and productivity. Last, we report results from bioclimate envelope models that predict suitable habitat for locally adapted genotypes under observed and predicted climate change. The combined results support assisted migration prescriptions and indicate that the risk of inaction likely exceeds the risk associated with changing established management practices. However, uncertainty in model projections also implies that we are restricted to a relatively short 20-year planning horizon for prescribing seed movement in reforestation programs. We believe that this study exemplifies a safe and realistic climate change adaptation strategy based on multiple sources of information and some understanding of the uncertainty associated with recommendations for assisted migration. Ad hoc migration prescriptions without a similar level of supporting information should be avoided in reforestation programs.

  19. Modeling human behavior in economics and social science.

    Science.gov (United States)

    Dolfin, M; Leonida, L; Outada, N

    2017-12-01

    The complex interactions between human behaviors and social economic sciences is critically analyzed in this paper in view of possible applications of mathematical modeling as an attainable interdisciplinary approach to understand and simulate the aforementioned dynamics. The quest is developed along three steps: Firstly an overall analysis of social and economic sciences indicates the main requirements that a contribution of mathematical modeling should bring to these sciences; subsequently the focus moves to an overview of mathematical tools and to the selection of those which appear, according to the authors bias, appropriate to the modeling; finally, a survey of applications is presented looking ahead to research perspectives. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. ECONOMIC FORECASTS BASED ON ECONOMETRIC MODELS USING EViews 5

    Directory of Open Access Journals (Sweden)

    Cornelia TomescuDumitrescu,

    2009-05-01

    Full Text Available The forecast of evolution of economic phenomena represent on the most the final objective of econometrics. It withal represent a real attempt of validity elaborate model. Unlike the forecasts based on the study of temporal series which have an recognizable inertial character the forecasts generated by econometric model with simultaneous equations are after to contour the future of ones of important economic variables toward the direct and indirect influences bring the bear on their about exogenous variables. For the relief of the calculus who the realization of the forecasts based on the econometric models its suppose is indicate the use of the specialized informatics programs. One of this is the EViews which is applied because it reduces significant the time who is destined of the econometric analysis and it assure a high accuracy of calculus and of the interpretation of results.

  1. Stochastic effects in a discretized kinetic model of economic exchange

    Science.gov (United States)

    Bertotti, M. L.; Chattopadhyay, A. K.; Modanese, G.

    2017-04-01

    Linear stochastic models and discretized kinetic theory are two complementary analytical techniques used for the investigation of complex systems of economic interactions. The former employ Langevin equations, with an emphasis on stock trade; the latter is based on systems of ordinary differential equations and is better suited for the description of binary interactions, taxation and welfare redistribution. We propose a new framework which establishes a connection between the two approaches by introducing random fluctuations into the kinetic model based on Langevin and Fokker-Planck formalisms. Numerical simulations of the resulting model indicate positive correlations between the Gini index and the total wealth, that suggest a growing inequality with increasing income. Further analysis shows, in the presence of a conserved total wealth, a simultaneous decrease in inequality as social mobility increases, in conformity with economic data.

  2. Impact of epidermal leaf mining by the aspen leaf miner (Phyllocnistis populiella) on the growth, physiology, and leaf longevity of quaking aspen.

    Science.gov (United States)

    Diane L. Wagner; Linda DeFoliart; Patricia Doak; Jenny Schneiderheinze

    2008-01-01

    The aspen leaf miner, Phyllocnistis populiella, feeds on the contents of epidermal cells on both top (adaxial) and bottom (abaxial) surfaces of quaking aspen leaves, leaving the photosynthetic tissue of the mesophyll intact. This type of feeding is taxonomically restricted to a small subset of leaf mining insects but can cause widespread plant...

  3. Nonlinear Economic Model Predictive Control Strategy for Active Smart Buildings

    DEFF Research Database (Denmark)

    Santos, Rui Mirra; Zong, Yi; Sousa, Joao M. C.

    2016-01-01

    Nowadays, the development of advanced and innovative intelligent control techniques for energy management in buildings is a key issue within the smart grid topic. A nonlinear economic model predictive control (EMPC) scheme, based on the branch-and-bound tree search used as optimization algorithm...... for solving the nonconvex optimization problem is proposed in this paper. A simulation using the nonlinear model-based controller to control the temperature levels of an intelligent office building (PowerFlexHouse) is addressed. Its performance is compared with a linear model-based controller. The nonlinear...

  4. Economic value added model upon conditions of banking company

    Directory of Open Access Journals (Sweden)

    Vlasta Kašparovská

    2008-01-01

    Full Text Available The content of this article is the application of the economic value added model (EVA upon the conditions of a banking company. Due to the character of banking business, which is in a different structure of financial sheet, it is not possible to use the standard model EVA for this banking company. The base of this article is the outlined of basic principles of the EVA mode in a non-banking company. Basic specified banking activity dissimilarities are analysed and a directed methodology adjustment of a model such as this, so that it is possible to use it for a banking company.

  5. Automated economic analysis model for hazardous waste minimization

    International Nuclear Information System (INIS)

    Dharmavaram, S.; Mount, J.B.; Donahue, B.A.

    1990-01-01

    The US Army has established a policy of achieving a 50 percent reduction in hazardous waste generation by the end of 1992. To assist the Army in reaching this goal, the Environmental Division of the US Army Construction Engineering Research Laboratory (USACERL) designed the Economic Analysis Model for Hazardous Waste Minimization (EAHWM). The EAHWM was designed to allow the user to evaluate the life cycle costs for various techniques used in hazardous waste minimization and to compare them to the life cycle costs of current operating practices. The program was developed in C language on an IBM compatible PC and is consistent with other pertinent models for performing economic analyses. The potential hierarchical minimization categories used in EAHWM include source reduction, recovery and/or reuse, and treatment. Although treatment is no longer an acceptable minimization option, its use is widespread and has therefore been addressed in the model. The model allows for economic analysis for minimization of the Army's six most important hazardous waste streams. These include, solvents, paint stripping wastes, metal plating wastes, industrial waste-sludges, used oils, and batteries and battery electrolytes. The EAHWM also includes a general application which can be used to calculate and compare the life cycle costs for minimization alternatives of any waste stream, hazardous or non-hazardous. The EAHWM has been fully tested and implemented in more than 60 Army installations in the United States

  6. Stand Composition, Tree Proximity and Size Have Minimal Effects on Leaf Function of Coexisting Aspen and Subalpine Fir.

    Directory of Open Access Journals (Sweden)

    Aaron C Rhodes

    Full Text Available Forest structural heterogeneity due to species composition, spatial relationships and tree size are widely studied patterns in forest systems, but their impacts on tree function are not as well documented. The objective of this study was to examine how stand composition, tree proximity relationships and tree size influence the leaf functional traits of aspen, an early successional species, and subalpine fir, a climax species. We measured foliar nutrients, nonstructural carbohydrates (aspen only, defense chemistry and xylem water potential of aspen and subalpine fir trees in three size classes growing in close proximity or independently from other trees under three stand conditions: aspen dominant, aspen-conifer mixed, and conifer dominant stands. Close proximity of subalpine fir to aspen reduced aspen's storage of starch in foliar tissue by 17% suggesting that competition between these species may have small effects on carbon metabolism in aspen leaves. Simple sugar (glucose + sucrose concentrations in aspen leaves were slightly higher in larger aspen trees than smaller trees. However, no differences were found in stem water potential, foliar concentrations of nitrogen, phosphorus, or secondary defense chemicals of aspen or subalpine fir across the gradients of stand composition, tree proximity or tree size. These results suggest that mechanisms of coexistence allow both aspen and subalpine fir to maintain leaf function across a wide range of stand structural characteristics. For aspen, resource sharing through its clonal root system and high resource storage capacity may partially contribute to its functional stability in mixed aspen-conifer stands.

  7. Economic Model Predictive Control for Spray Drying Plants

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert

    and MPC strategies to optimize the operation of four-stage spray dryers. The models are first-principle dynamic models with parameters identified from dryer specific experiments and powder properties identified from laboratory tests. A simulation model is used for detailed closed-loop simulations...... and a complexity reduced control model is used for state estimation and prediction in the controllers. These models facilitate development and comparison of control strategies. We develop two MPC strategies; a linear tracking MPC with a Real-Time Optimization layer (MPC with RTO) and an Economic Nonlinear MPC (E...... and sticky powder is avoided from building up on the dryer walls; 3) Demonstrate the industrial application of an MPC strategy to a full-scale industrial four-stage spray dryer. The main scientific contributions can be summarized to: - Modeling of a four-stage spray dryer. We develop new first-principles...

  8. Elevated Rocky Mountain elk numbers prevent positive effects of fire on quaking aspen (Populus tremuloides) recruitment

    Science.gov (United States)

    Smith, David Solance; Fettig, Stephen M.; Bowker, Matthew A.

    2016-01-01

    Quaking aspen (Populus tremuloides) is the most widespread tree species in North America and has supported a unique ecosystem for tens of thousands of years, yet is currently threatened by dramatic loss and possible local extinctions. While multiple factors such as climate change and fire suppression are thought to contribute to aspen’s decline, increased browsing by elk (Cervus elaphus), which have experienced dramatic population increases in the last ∼80 years, may severely inhibit aspen growth and regeneration. Fires are known to favor aspen recovery, but in the last several decades the spatial scale and intensity of wildfires has greatly increased, with poorly understood ramifications for aspen growth. Here, focusing on the 2000 Cerro Grande fire in central New Mexico – one of the earliest fires described as a “mega-fire” - we use three methods to examine the impact of elk browsing on aspen regeneration after a mega-fire. First, we use an exclosure experiment to show that aspen growing in the absence of elk were 3× taller than trees growing in the presence of elk. Further, aspen that were both protected from elk and experienced burning were 8.5× taller than unburned trees growing in the presence of elk, suggesting that the combination of release from herbivores and stimulation from fire creates the largest aspen growth rates. Second, using surveys at the landscape level, we found a correlation between elk browsing intensity and aspen height, such that where elk browsing was highest, aspen were shortest. This relationship between elk browsing intensity and aspen height was stronger in burned (r = −0.53) compared to unburned (r = −0.24) areas. Third, in conjunction with the landscape-level surveys, we identified possible natural refugia, microsites containing downed logs, shrubs etc. that may inhibit elk browsing by physically blocking aspen from elk or by impeding elk’s ability to move through the forest patch. We did not find any

  9. Economic model predictive control theory, formulations and chemical process applications

    CERN Document Server

    Ellis, Matthew; Christofides, Panagiotis D

    2017-01-01

    This book presents general methods for the design of economic model predictive control (EMPC) systems for broad classes of nonlinear systems that address key theoretical and practical considerations including recursive feasibility, closed-loop stability, closed-loop performance, and computational efficiency. Specifically, the book proposes: Lyapunov-based EMPC methods for nonlinear systems; two-tier EMPC architectures that are highly computationally efficient; and EMPC schemes handling explicitly uncertainty, time-varying cost functions, time-delays and multiple-time-scale dynamics. The proposed methods employ a variety of tools ranging from nonlinear systems analysis, through Lyapunov-based control techniques to nonlinear dynamic optimization. The applicability and performance of the proposed methods are demonstrated through a number of chemical process examples. The book presents state-of-the-art methods for the design of economic model predictive control systems for chemical processes. In addition to being...

  10. A non-linear model of economic production processes

    Science.gov (United States)

    Ponzi, A.; Yasutomi, A.; Kaneko, K.

    2003-06-01

    We present a new two phase model of economic production processes which is a non-linear dynamical version of von Neumann's neoclassical model of production, including a market price-setting phase as well as a production phase. The rate of an economic production process is observed, for the first time, to depend on the minimum of its input supplies. This creates highly non-linear supply and demand dynamics. By numerical simulation, production networks are shown to become unstable when the ratio of different products to total processes increases. This provides some insight into observed stability of competitive capitalist economies in comparison to monopolistic economies. Capitalist economies are also shown to have low unemployment.

  11. Gravity model used for the analysis of economic developments

    Directory of Open Access Journals (Sweden)

    Ion PÂRŢACHI

    2010-04-01

    Full Text Available In this article we study the influence of ethnic fragmentation on foreign trade in the countries of Southeastern Europe in the conditions of recent conflicts. The analysis of trade is done using the gravity model. The explanatory variables of economic foreign relations, as inter-state social structure and inter-state political relations, play an important role in this region, namely in the context of the economic transition, and of EU enlargement to the East.The gravity approach followed in the article allows to consider the multilateral resistance, by the introduction of the fixed effects, and the model is estimated by pseudo-Poisson of Maximum Likelihood, that allows to include the null trade flows. The results show a positive influence of ethnic fractionalization on the import flows, as well as a positive influence of the 1990 conflicts on the volume of trade.

  12. Regressional modeling and forecasting of economic growth for arkhangelsk region

    Directory of Open Access Journals (Sweden)

    Robert Mikhailovich Nizhegorodtsev

    2012-12-01

    Full Text Available The regression models of GRP, considering the impact of three main factors: investment in fixed assets, wages amount, and, importantly, the innovation factor –the expenditures for research and development, are constructed in this paper on the empirical data for Arkhangelsk region. That approach permits to evaluate explicitly the contribution of innovation to economic growth. Regression analysis is the main research instrument, all calculations areperformedin the Microsoft Excel. There were made meaningful conclusions regarding the potential of the region's GRP growth by various factors, including impacts of positive and negative time lags. Adequate and relevant models are the base for estimation and forecasting values of the dependent variable (GRP and evaluating their confidence intervals. The invented method of research can be used in factor assessment and prediction of regional economic growth, including growth by expectations.

  13. Estimation of Continuous Time Models in Economics: an Overview

    OpenAIRE

    Clifford R. Wymer

    2009-01-01

    The dynamics of economic behaviour is often developed in theory as a continuous time system. Rigorous estimation and testing of such systems, and the analysis of some aspects of their properties, is of particular importance in distinguishing between competing hypotheses and the resulting models. The consequences for the international economy during the past eighteen months of failures in the financial sector, and particularly the banking sector, make it essential that the dynamics of financia...

  14. The European Model: Economic Growth, Convergence and Cohesion

    Directory of Open Access Journals (Sweden)

    Aura Socol

    2006-10-01

    Full Text Available The european model is confronted with a potential crise. Economic convergence concerns the gaps in living standards between countries: are they closing or widening, and at what speed? Are relatively poor economies to remain poor for many generations? Are the rich countries of next century to be the same as relatively rich countries of nowadays? Is the degree of income inequality across economies increasing or falling over time? Posing these questions, motivating convergence debate, immediately raises the problem of the variable/variables that need to be considered. In our study, prior to providing answers to these questions, basic definitions concerning convergence in European model are followed by an overview of specific features, achievements and hurdles countries have had to overcome on their way from centrally planned towards market economy. After that, a summary of Solow-Swan model of economic growth is offered. Concept of convergence emerges here as a natural implication of the model. The distinctions between Solow-Swan model and endogenous growth model are stated. Finally, some measures of macroeconomic policy for sustainable growth are presented and interpreted in connection with real macroeconomic situation of the Romanian economy.

  15. Tax Compliance Models: From Economic to Behavioral Approaches

    Directory of Open Access Journals (Sweden)

    Larissa Margareta BĂTRÂNCEA

    2012-06-01

    Full Text Available The paper reviews the models of tax compliance with an emphasis on economic and behavioral perspectives. Although the standard tax evasion model of Allingham and Sandmo and other similar economic models capture some important aspects of tax compliance (i.e., taxpayers’ response to increases in tax rate, audit probability, penalty rate they do not suffice the need for an accurate prediction of taxpayers’ behavior. The reason is that they do not offer a comprehensive perspective on the sociological and psychological factors which shape compliance (i.e., attitudes, beliefs, norms, perceptions, motivations. Therefore, the researchers have considered examining taxpayers’ inner motivations, beliefs, perceptions, attitudes in order to accurately predict taxpayers’ behavior. As a response to their quest, behavioral models of tax compliance have emerged. Among the sociological and psychological factors which shape tax compliance, the ‘slippery slope’ framework singles out trust in authorities and the perception of the power of authorities. The aim of the paper is to contribute to the understanding of the reasons for which there is a need for a tax compliance model which incorporates both economic and behavioral features and why governments and tax authorities should consider these models when designing fiscal policies.

  16. Aspen Overstory Recruitment in Northern Yellowstone National Park During the Last 200 Years

    OpenAIRE

    Larsen, Eric J; Ripple, William J

    2001-01-01

    Using a monograph provided by Warren (1926) and two sets of aspen increment cores collected in 1997 and 1998, we analyzed aspen overstory recruitment in Yellowstone National Park (YNP) over the past 200 years. We found that successful aspen overstory recruitment occurred on the northern range of YNP from the middle to late 1700s until the 1920s, after which it essentially ceased. We hypothesized why the browsing influence of Rocky Mountain elk (Cervus elaphus) may be different now than it was...

  17. Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

    Science.gov (United States)

    Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

    2017-06-01

    High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  18. Controlling Hazel, Aspen Suckers, and Mountain Maple with Picloram

    Science.gov (United States)

    Donald A. Perala

    1971-01-01

    Tests showed that picloram/2,4-D mixture was equal to or superior to 2,4-D alone or a 2,4,5-D/2,4,5-T mixture in controlling hazel, aspen suckers, and mountain maple for reforestation purposes. Survival of red pine planted 9 months after treatment was not influenced by residual soil effects of picloram. However, foliar application contributed to mortality of...

  19. Financial Transaction Tax: Determination of Economic Impact Under DSGE Model

    Directory of Open Access Journals (Sweden)

    Veronika Solilová

    2015-01-01

    Full Text Available The discussion about the possible taxation of the financial sector has started in the European Union as a result of the financial crisis which has spread to the Europe from the United States in 2008 and consequently of the massive financial interventions by governments made in favour of the financial sector. On 14 February 2013, after rejection of the draft of the directive introducing a common system of financial transaction tax in 2011, the European Commission introduced the financial transaction tax through enhanced cooperation. The aim of the paper is to research economic impact of financial transaction tax on EU (EU27 or EU11 with respect to the DSGE model which was used for the determination of impacts. Based on our analysis the DSGE model can be considered as underestimated in case of the impact on economic growth and an overestimated in case of the revenue collection. Particularly, the overall impact of the financial transaction tax considering cascade effects of securities (tax rate 2.2% and derivatives (tax rate 0.2% is ranged between −4.752 and 1.472 percent points of GDP. And further, is assumed that the relocation effects of business/trade can be in average 40% causes a decline of expected tax revenues in the amount of 13bn EUR. Thus, at a time of fragile economic growth across the EU and the increased risk of recession in Europe, the introduction of the FTT should be undesirable.

  20. Mathematical modeling in economics, ecology and the environment

    CERN Document Server

    Hritonenko, Natali

    2013-01-01

    Updated to textbook form by popular demand, this second edition discusses diverse mathematical models used in economics, ecology, and the environmental sciences with emphasis on control and optimization. It is intended for graduate and upper-undergraduate course use, however, applied mathematicians, industry practitioners, and a vast number of interdisciplinary academics will find the presentation highly useful. Core topics of this text are: ·         Economic growth and technological development ·         Population dynamics and human impact on the environment ·         Resource extraction and scarcity ·         Air and water contamination ·         Rational management of the economy and environment ·         Climate change and global dynamics The step-by-step approach taken is problem-based and easy to follow. The authors aptly demonstrate that the same models may be used to describe different economic and environmental processes and that similar invest...

  1. 77 FR 60373 - Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and Piute...

    Science.gov (United States)

    2012-10-03

    ... stands by ungulates; improving native species diversity; reducing hazardous fuel accumulations; and...), effects from insects and disease, effects on livestock grazing management, overbrowsing of new aspen by...

  2. Adverse Influence of Radio Frequency Background on Trembling Aspen Seedlings: Preliminary Observations

    Directory of Open Access Journals (Sweden)

    Katie Haggerty

    2010-01-01

    Full Text Available Numerous incidents of aspen decline have been recorded in North America over the past half century, and incidents of very rapid mortality of aspen clones have been observed in Colorado since 2004. The radio frequency (RF environment of the earth has undergone major changes in the past two centuries due to the development and use of electricity in power and communications applications, and the anthropogenic RF background continues to increase in intensity and complexity. This study suggests that the RF background may have strong adverse effects on growth rate and fall anthocyanin production in aspen, and may be an underlying factor in aspen decline.

  3. Exploring regional economic convergence in Romania. A spatial modeling approach

    Directory of Open Access Journals (Sweden)

    Zizi GOSCHIN

    2017-12-01

    Full Text Available This paper explores spatial economic convergence in Romania, from the perspective of real GDP/capita, and examines how the shock of the recent economic crisis has affected the convergence process. Given the presence of spatial autocorrelation in the values of GDP per capita, we address the question of convergence in terms of both classic and spatial regression models, thus filling a gap in the Romanian literature on this topic. The empirical results seem to provide support for both absolute and relative beta divergence in GDP/capita, as well as sigma divergence among Romanian counties on the long run. This is the consequence of the two-speed regional development, with the capital region and some large cities thriving by attracting human capital and FDIs, while the lagging regions are systematically left behind. Failing to validate the neoclassical approach on convergence, our results rather support the new divergence theory based on polarization and centre-periphery inequality.

  4. Linking Simple Economic Theory Models and the Cointegrated Vector AutoRegressive Model

    DEFF Research Database (Denmark)

    Møller, Niels Framroze

    This paper attempts to clarify the connection between simple economic theory models and the approach of the Cointegrated Vector-Auto-Regressive model (CVAR). By considering (stylized) examples of simple static equilibrium models, it is illustrated in detail, how the theoretical model and its...

  5. Stand Composition, Tree Proximity and Size Have Minimal Effects on Leaf Function of Coexisting Aspen and Subalpine Fir

    Science.gov (United States)

    Rhodes, Aaron C.; Barney, Trevor; St. Clair, Samuel B.

    2016-01-01

    Forest structural heterogeneity due to species composition, spatial relationships and tree size are widely studied patterns in forest systems, but their impacts on tree function are not as well documented. The objective of this study was to examine how stand composition, tree proximity relationships and tree size influence the leaf functional traits of aspen, an early successional species, and subalpine fir, a climax species. We measured foliar nutrients, nonstructural carbohydrates (aspen only), defense chemistry and xylem water potential of aspen and subalpine fir trees in three size classes growing in close proximity or independently from other trees under three stand conditions: aspen dominant, aspen-conifer mixed, and conifer dominant stands. Close proximity of subalpine fir to aspen reduced aspen’s storage of starch in foliar tissue by 17% suggesting that competition between these species may have small effects on carbon metabolism in aspen leaves. Simple sugar (glucose + sucrose) concentrations in aspen leaves were slightly higher in larger aspen trees than smaller trees. However, no differences were found in stem water potential, foliar concentrations of nitrogen, phosphorus, or secondary defense chemicals of aspen or subalpine fir across the gradients of stand composition, tree proximity or tree size. These results suggest that mechanisms of coexistence allow both aspen and subalpine fir to maintain leaf function across a wide range of stand structural characteristics. For aspen, resource sharing through its clonal root system and high resource storage capacity may partially contribute to its functional stability in mixed aspen-conifer stands. PMID:27124496

  6. Toward linking demographic and economic models for impact assessment

    International Nuclear Information System (INIS)

    Williams, C.A.; Meenan, C.D.

    1991-01-01

    One of the objectives of the Yucca Mountain Project, in Southern Nevada, is to evaluate the effects of the development of a high-level nuclear waste repository. As described in the Section 175 Report to the Congress of the US, the temporal scope of this repository project encompasses approximately 70 years and includes four phases: Site characterization and licensing, construction, operation, and closure and decommissioning. If retrieval of the waste were to be required, the temporal scope of the repository project could be extended to approximately 100 years. The study of the potential socioeconomic effects of this project is the foundation for this paper. This paper focuses on the economic and demographic aspects and a possible method to interface the two. First, the authors briefly discuss general socioeconomic modeling theory from a county level view point, as well as methods for the apportionment of county level data to sub-county areas. Next, the authors describe the unique economic and demographic conditions which exist in Nevada at both the state and county levels. Finally, the authors evaluate a possible procedure for analyzing repository effects at a sub-county level; this involves discussion of an interface linking the economic and demographic aspects, which is based on the reconciliation of supply and demand for labor. The authors conclude that the basis for further model development may rely on the interaction of supply and demand to produce change in wage rates. These changes in expected wages should be a justification for allocating economic migrants (who may respond to Yucca Mountain Project development) into various communities

  7. Unification and mechanistic detail as drivers of model construction: models of networks in economics and sociology.

    Science.gov (United States)

    Kuorikoski, Jaakko; Marchionni, Caterina

    2014-12-01

    We examine the diversity of strategies of modelling networks in (micro) economics and (analytical) sociology. Field-specific conceptions of what explaining (with) networks amounts to or systematic preference for certain kinds of explanatory factors are not sufficient to account for differences in modelling methodologies. We argue that network models in both sociology and economics are abstract models of network mechanisms and that differences in their modelling strategies derive to a large extent from field-specific conceptions of the way in which a good model should be a general one. Whereas the economics models aim at unification, the sociological models aim at a set of mechanism schemas that are extrapolatable to the extent that the underlying psychological mechanisms are general. These conceptions of generality induce specific biases in mechanistic explanation and are related to different views of when knowledge from different fields should be seen as relevant.

  8. Incorporating incorporating economic models into seasonal pool conservation planning

    Science.gov (United States)

    Freeman, Robert C.; Bell, Kathleen P.; Calhoun, Aram J.K.; Loftin, Cyndy

    2012-01-01

    Massachusetts, New Jersey, Connecticut, and Maine have adopted regulatory zones around seasonal (vernal) pools to conserve terrestrial habitat for pool-breeding amphibians. Most amphibians require access to distinct seasonal habitats in both terrestrial and aquatic ecosystems because of their complex life histories. These habitat requirements make them particularly vulnerable to land uses that destroy habitat or limit connectivity (or permeability) among habitats. Regulatory efforts focusing on breeding pools without consideration of terrestrial habitat needs will not ensure the persistence of pool-breeding amphibians. We used GIS to combine a discrete-choice, parcel-scale economic model of land conversion with a landscape permeability model based on known habitat requirements of wood frogs (Lithobates sylvaticus) in Maine (USA) to examine permeability among habitat elements for alternative future scenarios. The economic model predicts future landscapes under different subdivision open space and vernal pool regulatory requirements. Our model showed that even “no build” permit zones extending 76 m (250 ft) outward from the pool edge were insufficient to assure permeability among required habitat elements. Furthermore, effectiveness of permit zones may be inconsistent due to interactions with other growth management policies, highlighting the need for local and state planning for the long-term persistence of pool-breeding amphibians in developing landscapes.

  9. Clinical laboratory as an economic model for business performance analysis

    Science.gov (United States)

    Buljanović, Vikica; Patajac, Hrvoje; Petrovečki, Mladen

    2011-01-01

    Aim To perform SWOT (strengths, weaknesses, opportunities, and threats) analysis of a clinical laboratory as an economic model that may be used to improve business performance of laboratories by removing weaknesses, minimizing threats, and using external opportunities and internal strengths. Methods Impact of possible threats to and weaknesses of the Clinical Laboratory at Našice General County Hospital business performance and use of strengths and opportunities to improve operating profit were simulated using models created on the basis of SWOT analysis results. The operating profit as a measure of profitability of the clinical laboratory was defined as total revenue minus total expenses and presented using a profit and loss account. Changes in the input parameters in the profit and loss account for 2008 were determined using opportunities and potential threats, and economic sensitivity analysis was made by using changes in the key parameters. The profit and loss account and economic sensitivity analysis were tools for quantifying the impact of changes in the revenues and expenses on the business operations of clinical laboratory. Results Results of simulation models showed that operational profit of €470 723 in 2008 could be reduced to only €21 542 if all possible threats became a reality and current weaknesses remained the same. Also, operational gain could be increased to €535 804 if laboratory strengths and opportunities were utilized. If both the opportunities and threats became a reality, the operational profit would decrease by €384 465. Conclusion The operational profit of the clinical laboratory could be significantly reduced if all threats became a reality and the current weaknesses remained the same. The operational profit could be increased by utilizing strengths and opportunities as much as possible. This type of modeling may be used to monitor business operations of any clinical laboratory and improve its financial situation by

  10. Clinical laboratory as an economic model for business performance analysis.

    Science.gov (United States)

    Buljanović, Vikica; Patajac, Hrvoje; Petrovecki, Mladen

    2011-08-15

    To perform SWOT (strengths, weaknesses, opportunities, and threats) analysis of a clinical laboratory as an economic model that may be used to improve business performance of laboratories by removing weaknesses, minimizing threats, and using external opportunities and internal strengths. Impact of possible threats to and weaknesses of the Clinical Laboratory at Našice General County Hospital business performance and use of strengths and opportunities to improve operating profit were simulated using models created on the basis of SWOT analysis results. The operating profit as a measure of profitability of the clinical laboratory was defined as total revenue minus total expenses and presented using a profit and loss account. Changes in the input parameters in the profit and loss account for 2008 were determined using opportunities and potential threats, and economic sensitivity analysis was made by using changes in the key parameters. The profit and loss account and economic sensitivity analysis were tools for quantifying the impact of changes in the revenues and expenses on the business operations of clinical laboratory. Results of simulation models showed that operational profit of €470 723 in 2008 could be reduced to only €21 542 if all possible threats became a reality and current weaknesses remained the same. Also, operational gain could be increased to €535 804 if laboratory strengths and opportunities were utilized. If both the opportunities and threats became a reality, the operational profit would decrease by €384 465. The operational profit of the clinical laboratory could be significantly reduced if all threats became a reality and the current weaknesses remained the same. The operational profit could be increased by utilizing strengths and opportunities as much as possible. This type of modeling may be used to monitor business operations of any clinical laboratory and improve its financial situation by implementing changes in the next fiscal

  11. 2012 Aspen Winter Conferences on High Energy and Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Olivier, Dore [California Inst. of Technology (CalTech), Pasadena, CA (United States); Fox, Patrick [Aspen Center for Physics, CO (United States); Furic, Ivan [Univ. of Florida, Gainesville, FL (United States); Halkiadakis, Eva [Rutgers Univ., Piscataway, NJ (United States); Schmidt, Fabian [California Inst. of Technology (CalTech), Pasadena, CA (United States); Senatore, Leonardo [Stanford Univ., CA (United States); Smith, Kendrick M. [Princeton Univ., NJ (United States); Whiteson, Daniel [Univ. of California, Irvine, CA (United States)

    2012-05-01

    Aspen Center for Physics Project Summary DE-SC0007313 Budget Period: 1/1/2012 to 12/31/2012 The Hunt for New Particles, from the Alps to the Plains to the Rockies The 2012 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 11 to February 17, 2012. Sixty-seven participants from nine countries, and several universities and national labs attended the workshop titled, The Hunt for New Particles, from the Alps to the Plains to the Rockies. There were 53 formal talks, and a considerable number of informal discussions held during the week. The weeks events included a public lecture-Hunting the Dark Universe given by Neal Weiner from New York University) and attended by 237 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists conducted by Spencer Chang (University of Oregon), Matthew Reece (Harvard University) and Julia Shelton (Yale University) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by John Campbell (Fermilab), Patrick Fox (Fermilab), Ivan Furic (University of Florida), Eva Halkiadakis (Rutgers University) and Daniel Whiteson (University of California Irvine). Additional information is available at http://indico.cern.ch/conferenceDisplay.py?confId=143360. Inflationary Theory and its Confrontation with Data in the Planck Era The 2012 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was Inflationary Theory and its Confrontation with Data in the Planck Era. It was held from January 30 to February 4, 2012. The 62 participants came from 7 countries and attended 43 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists

  12. Modelling the lifetime economic consequences of glaucoma in France.

    Science.gov (United States)

    Philippe Nordmann, Jean; Lafuma, Antoine; Berdeaux, Gilles

    2009-03-01

    To estimate the lifetime economic consequences of glaucoma in France. A Markov model estimated the average discounted outcome and cost of glaucoma treatment over a patient's lifetime. Clinical states were defined as first- to fourth-line drugs, no treatment, laser therapy, surgery, blindness and death. After each failure (always after the fourth-line drug) patients could receive either laser treatment or surgery followed by no treatment, or a new treatment. A societal perspective was adopted. Sensitivity analyses were performed. Discounted medical costs were euro 7,322 for ocular hypertension treatment (OHT) and euro 8,488 for a glaucoma patient. Social costs of OHT and glaucoma patients exceeded medical costs. First-line use of the most effective drug would reduce medical and social costs. Societal willingness to pay for the vision benefit would equal the medical costs. Treatment initiated with the most effective drug is a cost saving strategy. Public health decisions in glaucoma treatment should take a broad economic view embracing the lifetime duration of the disease. There is still a place both within and outside the healthcare system for therapeutic innovations with important economic consequences that bring high added value to patients.

  13. Nonlinear Economic Model Predictive Control Strategy for Active Smart Buildings

    DEFF Research Database (Denmark)

    Santos, Rui Mirra; Zong, Yi; Sousa, Joao M. C.

    2016-01-01

    Nowadays, the development of advanced and innovative intelligent control techniques for energy management in buildings is a key issue within the smart grid topic. A nonlinear economic model predictive control (EMPC) scheme, based on the branch-and-bound tree search used as optimization algorithm...... for solving the nonconvex optimization problem is proposed in this paper. A simulation using the nonlinear model-based controller to control the temperature levels of an intelligent office building (PowerFlexHouse) is addressed. Its performance is compared with a linear model-based controller. The nonlinear...... controller is shown very reliable keeping the comfort levels in the two considered seasons and shifting the load away from peak hours in order to achieve the desired flexible electricity consumption....

  14. Methodology and basic algorithms of the Livermore Economic Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.B.

    1981-03-17

    The methodology and the basic pricing algorithms used in the Livermore Economic Modeling System (EMS) are described. The report explains the derivations of the EMS equations in detail; however, it could also serve as a general introduction to the modeling system. A brief but comprehensive explanation of what EMS is and does, and how it does it is presented. The second part examines the basic pricing algorithms currently implemented in EMS. Each algorithm's function is analyzed and a detailed derivation of the actual mathematical expressions used to implement the algorithm is presented. EMS is an evolving modeling system; improvements in existing algorithms are constantly under development and new submodels are being introduced. A snapshot of the standard version of EMS is provided and areas currently under study and development are considered briefly.

  15. Direct regional energy/economic modeling (DREEM) design

    Energy Technology Data Exchange (ETDEWEB)

    Hall, P.D.; Pleatsikas, C.J.

    1979-10-01

    This report summarizes an investigation into the use of regional and multiregional economic models for estimating the indirect and induced impacts of Federally-mandated energy policies. It includes an examination of alternative types of energy policies that can impact regional economies and the available analytical frameworks for measuring the magnitudes and spatial extents of these impacts. One such analytical system, the National Regional Impact Evaluation System (NRIES), currently operational in the Bureau of Economic Analysis (BEA), is chosen for more detailed investigation. The report summarizes the models capabilities for addressing various energy policy issues and then demonstrates the applicability of the model in specified contexts by developing appropriate input data for three scenarios. These scenarios concern the multi-state impacts of alternative coal-mining-development decisions, multi-regional impacts of macroeconomic change, and the comprehensive effects of an alternative national energy supply trajectory. On the basis of this experience, the capabilities of NRIES for analyzing energy-policy issues are summarized in a concluding chapter.

  16. Empirical Bayes Credibility Models for Economic Catastrophic Losses by Regions

    Directory of Open Access Journals (Sweden)

    Jindrová Pavla

    2017-01-01

    Full Text Available Catastrophic events affect various regions of the world with increasing frequency and intensity. The number of catastrophic events and the amount of economic losses is varying in different world regions. Part of these losses is covered by insurance. Catastrophe events in last years are associated with increases in premiums for some lines of business. The article focus on estimating the amount of net premiums that would be needed to cover the total or insured catastrophic losses in different world regions using Bühlmann and Bühlmann-Straub empirical credibility models based on data from Sigma Swiss Re 2010-2016. The empirical credibility models have been developed to estimate insurance premiums for short term insurance contracts using two ingredients: past data from the risk itself and collateral data from other sources considered to be relevant. In this article we deal with application of these models based on the real data about number of catastrophic events and about the total economic and insured catastrophe losses in seven regions of the world in time period 2009-2015. Estimated credible premiums by world regions provide information how much money in the monitored regions will be need to cover total and insured catastrophic losses in next year.

  17. Partial differential equation models in the socio-economic sciences.

    Science.gov (United States)

    Burger, Martin; Caffarelli, Luis; Markowich, Peter A

    2014-11-13

    Mathematical models based on partial differential equations (PDEs) have become an integral part of quantitative analysis in most branches of science and engineering, recently expanding also towards biomedicine and socio-economic sciences. The application of PDEs in the latter is a promising field, but widely quite open and leading to a variety of novel mathematical challenges. In this introductory article of the Theme Issue, we will provide an overview of the field and its recent boosting topics. Moreover, we will put the contributions to the Theme Issue in an appropriate perspective. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  18. A mean-field game economic growth model

    KAUST Repository

    Gomes, Diogo A.

    2016-08-05

    Here, we examine a mean-field game (MFG) that models the economic growth of a population of non-cooperative, rational agents. In this MFG, agents are described by two state variables - the capital and consumer goods they own. Each agent seeks to maximize his/her utility by taking into account statistical data about the whole population. The individual actions drive the evolution of the players, and a market-clearing condition determines the relative price of capital and consumer goods. We study the existence and uniqueness of optimal strategies of the agents and develop numerical methods to compute these strategies and the equilibrium price.

  19. ANALYSIS OF ECONOMIC MODELS OF POTATO PRODUCTION IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Miomir JOVANOVIC

    2014-04-01

    Full Text Available The northern region of Montenegro represents a very important resource for agricultural production. However, the depopulation of the analysed area, pronounced in-kind character of production without significant participation of market producers, lack of market research, stronger vertical and horizontal connection between primary production and processing sectors have significant impacts causing the low level of competitiveness of agricultural production. Potato production in the analysed area has recorded positive trends in last ten years. This paper presents economic models of agriculture households on the analysed area from the potatoes production point of view.

  20. Partial differential equation models in the socio-economic sciences

    KAUST Repository

    Burger, Martin

    2014-10-06

    Mathematical models based on partial differential equations (PDEs) have become an integral part of quantitative analysis in most branches of science and engineering, recently expanding also towards biomedicine and socio-economic sciences. The application of PDEs in the latter is a promising field, but widely quite open and leading to a variety of novel mathematical challenges. In this introductory article of the Theme Issue, we will provide an overview of the field and its recent boosting topics. Moreover, we will put the contributions to the Theme Issue in an appropriate perspective.

  1. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    International Nuclear Information System (INIS)

    Bassyouni, M.; Waheed ul Hasan, Syed; Abdel-Aziz, M.H.; Abdel-hamid, S.M.-S.; Naveed, Shahid; Hussain, Ahmed; Ani, Farid Nasir

    2014-01-01

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO 2 and CH 4 in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H 2 = 56.27%, CO = 21.71%, CO 2 = 18.24%, CH 4 = 3.78%). Increasing steam to biomass ratio increases CO 2 and H 2 at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas

  2. Economic man as model man: Ideal types, idealization and caricatures

    NARCIS (Netherlands)

    Morgan, M.S.

    2006-01-01

    Economics revolves around a central character: "economic man." As historians, we are all familiar with various episodes in the history of this character, and we appreciate his ever-changing aspect even while many of our colleagues in economics think the rational economic agent of neoclassical

  3. Process model economics of xanthan production from confectionery industry wastewaters.

    Science.gov (United States)

    Bajić, Bojana Ž; Vučurović, Damjan G; Dodić, Siniša N; Grahovac, Jovana A; Dodić, Jelena M

    2017-12-01

    In this research a process and cost model for a xanthan production facility was developed using process simulation software (SuperPro Designer ® ). This work represents a novelty in the field for two reasons. One is that xanthan gum has been produced from several wastes but never from wastewaters from confectionery industries. The other more important is that the aforementioned software, which in intended exclusively for bioprocesses, is used for generating a base case, i.e. starting point for transferring the technology to industrial scales. Previously acquired experimental knowledge about using confectionery wastewaters from five different factories as substitutes for commercially used cultivation medium have been incorporated into the process model in order to obtain an economic viability of implementing such substrates. A lower initial sugar content in the medium based on wastewater (28.41 g/L) compared to the synthetic medium (30.00 g/L) gave a lower xanthan content at the end of cultivation (23.98 and 26.27 g/L, respectively). Although this resulted in somewhat poorer economic parameters, they were still in the range of being an investment of interest. Also the possibility of utilizing a cheap resource (waste) and reducing pollution that would result from its disposal has a positive effect on the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Economic implications of Japan's aging population: a macro-economic demographic modeling approach.

    Science.gov (United States)

    Ogawa, N

    1982-01-01

    This paper utilizes a macroeconomic demographic model to analyze the probable impact of population aging on various public programs in Japan. Rapid fertility decline aided by mortality decline has caused the proportion of the Japanese population aged 65 and over to increase from 4.9% in 1950 to 9.0% in 1980. A population projection based on the 1975 population census assumes a recovery of fertility from a total fertility rate (TFR) of 1.9 in 1976 to 2.16 in 1980 and a gradual decline to 2.1 by 1987, while an alternative projection assumes a continuing fertility decline to a TFR of 1.65 in 2025. According to these assumptions, in 2025 18.12% to 21.29% of the total population would be aged 65 or over and 38.66% to 43.80% of the working age population would be aged 45-64. A macroeconomic neoclassical growth model with some Keynesian features was formulated to evaluate the future impact of population aging on social security programs. Population changes are transmitted to economic variables in the model through the supply of labor, level of savings, public health care plans, and old-age pension schemes. The simulation experiments included the 2 population projections and 2 alternative production functions, 1 with the quality of labor incorporated and 1 without. The results indicated that, regardless of the population projection and production function used, the growth of the economy is likely to slow to 1 or 0% in the beginning of the next century due to decreased growth of the labor force and a change in its quality due to age-compositional variations. Public health insurance schemes and pension plans will require increasing financial resources as a result of accelerated population aging; depending on the choice of benefit levels, the proportion of national income allocated to them is expected to range from 14%-40% in the year 2010. Per capita gross national product will continue to grow despite decreased economic growth, but savings might be adversely affected if the

  5. OBJECT ORIENTED MODELLING, A MODELLING METHOD OF AN ECONOMIC ORGANIZATION ACTIVITY

    Directory of Open Access Journals (Sweden)

    TĂNĂSESCU ANA

    2014-05-01

    Full Text Available Now, most economic organizations use different information systems types in order to facilitate their activity. There are different methodologies, methods and techniques that can be used to design information systems. In this paper, I propose to present the advantages of using the object oriented modelling at the information system design of an economic organization. Thus, I have modelled the activity of a photo studio, using Visual Paradigm for UML as a modelling tool. For this purpose, I have identified the use cases for the analyzed system and I have presented the use case diagram. I have, also, realized the system static and dynamic modelling, through the most known UML diagrams.

  6. Fuzzy economic production quantity model with time dependent demand rate

    Directory of Open Access Journals (Sweden)

    Susanta Kumar Indrajitsingha

    2016-09-01

    Full Text Available Background: In this paper, an economic production quantity model is considered under a fuzzy environment. Both the demand cost and holding cost are considered using fuzzy pentagonal numbers. The Signed Distance Method is used to defuzzify the total cost function. Methods: The results obtained by these methods are compared with the help of a numerical example. Sensitivity analysis is also carried out to explore the effect of changes in the values of some of the system parameters. Results and conclusions: The fuzzy EPQ model with time dependent demand rate was presented together with the possible implementation. The behavior of changes in parameters was analyzed. The possible extension of the implementation of this method was presented.

  7. Factors influencing epiphytic lichen communities in aspen-associated forests of the Bear River Range, Idaho and Utah

    Science.gov (United States)

    Paul C. Rogers

    2007-01-01

    In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing...

  8. Habitone analysis of quaking aspen in the Utah Book Cliffs: Effects of site water demand and conifer cover

    Science.gov (United States)

    Joseph O. Sexton; R. Douglas Ramsey; Dale L. Bartos

    2006-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widely distributed tree species in North America, but its presence is declining across much of the Western United States. Aspen decline is complex, but results largely from two factors widely divergent in temporal scale: (1) Holocene climatic drying of the region has led to water limitation of aspen seedling...

  9. Allozyme and microsatellite data reveal small clone size and high genetic diversity in aspen in the southern Cascade Mountains

    Science.gov (United States)

    Jennifer DeWoody; Thomas H. Rickman; Bobette E. Jones; Valerie D. Hipkins

    2009-01-01

    The most widely distributed tree in North America, quaking aspen (Populus tremuloides, Michx.), reproduces sexually via seed and clonally via suckers. The size of aspen clones varies geographically, generally smaller in the east and large in the arid Intermountain West. In order to describe clone size and genetic structure of aspen in the southern Cascade...

  10. The aspen mortality summit; December 18 and 19, 2006; Salt Lake City, UT

    Science.gov (United States)

    Dale L. Bartos; Wayne D. Shepperd

    2010-01-01

    The USDA Forest Service Rocky Mountain Research Station sponsored an aspen summit meeting in Salt Lake City, Utah, on December 18 and19, 2006, to discuss the rapidly increasing mortality of aspen (Populus tremuloides) throughout the western United States. Selected scientists, university faculty, and managers from Federal, State, and non-profit agencies with experience...

  11. Nest-site selection and nest survival of Lewis's woodpecker in aspen riparian woodlands

    Science.gov (United States)

    Karen R. Newlon; Victoria A. Saab

    2011-01-01

    Riparian woodlands of aspen (Populus tremuloides) provide valuable breeding habitat for several cavity-nesting birds. Although anecdotal information for this habitat is available for Lewis's Woodpecker (Melanerpes lewis), no study has previously examined the importance of aspen woodlands to this species' breeding biology. From 2002 to 2004, we monitored 76...

  12. 76 FR 77591 - Surety Companies Acceptable on Federal Bonds: Aspen American Insurance Company

    Science.gov (United States)

    2011-12-13

    ... Fiscal Service Surety Companies Acceptable on Federal Bonds: Aspen American Insurance Company AGENCY.... 9305 to the following company: Aspen American Insurance Company (NAIC 43460). Business Address: 175... subject to subsequent annual renewal as long as the companies remain qualified (see 31 CFR part 223). A...

  13. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Sharkey, Thomas D.; Calfapietra, Carlo; Karnosky, David F.

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO 2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO 2 protected photosynthesis of both species against moderate heat stress. Elevated CO 2 increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO 2 treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO 2 were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO 2 . Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO 2 confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  14. Scaling Aspen-FACE experimental results to century and landscape scales

    Science.gov (United States)

    Eric J. Gustafson; Mark E. Kubiske; Brian R. Sturtevant; Brian R. Miranda

    2013-01-01

    The Aspen-FACE experiment generated 11 years of empirical data on the effect of CO2 enrichment and elevated ozone on the growth of field-grown trees (maple, birch and six aspen clones) in northern Wisconsin, but it is not known how these short-term plot-level responses might play out at the landscape scale over multiple decades where competition...

  15. 75 FR 13805 - Aspen Group Resources Corp., Commercial Concepts, Inc., Desert Health Products, Inc., Equalnet...

    Science.gov (United States)

    2010-03-23

    ... COMMISSION Aspen Group Resources Corp., Commercial Concepts, Inc., Desert Health Products, Inc., Equalnet Communications Corp., Geneva Steel Holdings Corp., Orderpro Logistics, Inc. (n/k/a Securus Renewable Energy, Inc... Aspen Group Resources Corp. because it has not filed any periodic reports since the period ended...

  16. Response of transplanted aspen to irrigation and weeding on a Colorado reclaimed surface coal mine

    Science.gov (United States)

    Robert C. Musselman; Wayne D. Shepperd; Frederick W. Smith; Lance A. Asherin; Brian W. Gee

    2012-01-01

    Successful re-establishment of aspen (Populus tremuloides Michx.) on surface-mined lands in the western United States is problematic because the species generally regenerates vegetatively by sprouting from parent roots in the soil; however, topsoil is removed in the mining process. Previous attempts to plant aspen on reclaimed mine sites have failed because...

  17. Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

    Science.gov (United States)

    Buck, Joshua R; St Clair, Samuel B

    2012-01-01

    Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.

  18. Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

    Directory of Open Access Journals (Sweden)

    Joshua R Buck

    Full Text Available Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3 and NH(4 were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.

  19. Harvesting Impacts on Soil Properties and Tree Regeneration in Pure and Mixed Aspen Stands

    Science.gov (United States)

    Melissa J. Arikian; Kiaus J. Peuttmann; Alaina L. Davis; George E. Host; John Zasada

    1999-01-01

    Impacts of clearcutting and selective harvesting on pure aspen/mixed aspen hardwood stands were examined in northern Minnesota. We studied these impacts on 18 stands, which were harvested 4 to 11 years ago and received no further treatment. In each stand, residual composition, soil compaction, and tree regeneration were determined along a gradient of disturbance in the...

  20. Simulation of Quaking Aspen Potential Fire Behavior in Northern Utah, USA

    Directory of Open Access Journals (Sweden)

    R. Justin DeRose

    2014-12-01

    Full Text Available Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread and torching (surface to crown fire spread were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion of aspen in the stand. Results showed a strong effect of species composition on crowning, but only under moderate fire weather, where aspen-dominated stands were unlikely to crown or torch. Although rarely observed in actual fires, conifer-dominated stands were likely to crown but not to torch, an example of “hysteresis” in crown fire behavior. Results support the hypothesis that potential crown fire behavior varies across a gradient of aspen dominance and fire weather, where it was likely under extreme and severe fire weather, and unlikely under moderate and high fire weather. Furthermore, the “fire-proof” nature of aspen stands broke down across the gradient of aspen dominance and fire weather.

  1. Landscape-scale dynamics of aspen in Rocky Mountain National Park, Colorado

    Science.gov (United States)

    Margot W. Kaye; Kuni Suzuki; Dan Binkley; Thomas J. Stohlgren

    2001-01-01

    Past studies of quaking aspen in Rocky Mountain National Park suggested that the aspen population is declining due to intensive browsing by elk (Cervus elaphus). These studies were conducted in the elk winter range, an area of intensive elk impact. The elk summer range experiences less intense grazing pressure. We tested the hypothesis that impacts of elk would be...

  2. Hybrid Aspen Response to Shearing in Minnesota: Implications for Biomass Production

    Science.gov (United States)

    Grant M. Domke; Andrew J. David; Anthony W. D' Amato; Alan R. Ek; Gary W. Wycoff

    2011-01-01

    There is great potential for the production of woody biomass feedstocks from hybrid aspen stands; however, little is known about the response of these systems to silvicultural treatments, such as shearing. We sought to address this need by integrating results from more than 20 years of individual tree and yield measurements in hybrid aspen (Populus tremuloides Mich. ×...

  3. Decline of aspen (Populus tremuloides) in the Interior West [Abstract 2

    Science.gov (United States)

    Dale L. Bartos

    1997-01-01

    It is commonly recognized that aspen (Populus tremuloides) ecosystems in the Interior West provide numerous benefits: (1) forage for livestock, (2) habitat for wildlife, (3) water for downstream users, (4) esthetics, (5) sites for recreational opportunities, (6) wood fiber, and (7) landscape diversity. Loss or potential loss of aspen on these lands can be attributed...

  4. The Budget and Economic Outlook: Fiscal Years 2008 to 2017

    Science.gov (United States)

    2007-01-01

    Federal Reserve Board; Aspen Publishers, Inc., Blue Chip Economic Indicators (January 10, 2007); Council of Economic Advisers, Department of the...Partnership Act 9/30/08 n.a. n.a. * * * * * * * * * -0.1 -0.2 Biodiesel Credits 12/31/08 n.a. n.a. -0.1 -0.1 -0.1 -0.2 -0.2 -0.2 -0.2 -0.2 -0.2 -0.5 -1.6...private-sector economic forecasts compiled and published monthly by Aspen Publishers, Inc. book depreciation: See depreciation. book profits: Profits

  5. Agricultural climate impacts assessment for economic modeling and decision support

    Science.gov (United States)

    Thomson, A. M.; Izaurralde, R. C.; Beach, R.; Zhang, X.; Zhao, K.; Monier, E.

    2013-12-01

    A range of approaches can be used in the application of climate change projections to agricultural impacts assessment. Climate projections can be used directly to drive crop models, which in turn can be used to provide inputs for agricultural economic or integrated assessment models. These model applications, and the transfer of information between models, must be guided by the state of the science. But the methodology must also account for the specific needs of stakeholders and the intended use of model results beyond pure scientific inquiry, including meeting the requirements of agencies responsible for designing and assessing policies, programs, and regulations. Here we present methodology and results of two climate impacts studies that applied climate model projections from CMIP3 and from the EPA Climate Impacts and Risk Analysis (CIRA) project in a crop model (EPIC - Environmental Policy Indicator Climate) in order to generate estimates of changes in crop productivity for use in an agricultural economic model for the United States (FASOM - Forest and Agricultural Sector Optimization Model). The FASOM model is a forward-looking dynamic model of the US forest and agricultural sector used to assess market responses to changing productivity of alternative land uses. The first study, focused on climate change impacts on the UDSA crop insurance program, was designed to use available daily climate projections from the CMIP3 archive. The decision to focus on daily data for this application limited the climate model and time period selection significantly; however for the intended purpose of assessing impacts on crop insurance payments, consideration of extreme event frequency was critical for assessing periodic crop failures. In a second, coordinated impacts study designed to assess the relative difference in climate impacts under a no-mitigation policy and different future climate mitigation scenarios, the stakeholder specifically requested an assessment of a

  6. Anticipating the uncertain: economic modeling and climate change policy

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Svenn

    2012-11-01

    With this thesis I wish to contribute to the understanding of how uncertainty and the anticipation of future events by economic actors affect climate policies. The thesis consists of four papers. Two papers are analytical models which explicitly consider that emissions are caused by extracting scarce fossil fuels which in the future must be replaced by clean technologies. The other two are so called numerical integrated assessment models. Such models represent the world economy, the climate system and the interactions between those two quantitatively, complementing more abstract theoretical work. Should policy makers discriminate between subsidizing renewable energy sources such as wind or solar power, and technologies such as carbon capture and storage (CCS)? Focusing only on the dynamic supply of fossil fuels and hence Co{sub 2}, we find here that cheaper future renewables cause extraction to speed up, lower costs of CCS may delay it. CCS hence may dampen the dynamic inefficiency caused by the absence of comprehensive climate policies today. Does it matter whether uncertainty about future damage assessment is due to scientific complexities or stems from the political process? In paper two, I find that political and scientific uncertainties have opposing effects on the incentives to investment in renewables and the extraction of fossil fuels: The prospect of scientific learning about the climate system increases investment incentives and, ceteris paribus, slows extraction down; uncertainty about future political constellations does the opposite. The optimal carbon tax under scientific uncertainty equals expected marginal damages, whereas political uncertainty demands a tax below marginal damages that decreases over time. Does uncertainty about economic growth impact optimal climate policy today? Here we are the first to consistently analyze how uncertainty about future economic growth affects optimal emission reductions and the optimal social cost of carbon. We

  7. Economical analysis based on a simplified model of micro distillery

    International Nuclear Information System (INIS)

    Bristoti, A.; Adams, R.

    1987-01-01

    The investment costs of the hydrate alcohol distillery as well as the energy balance of its production made inviable its diffusion on a small scale. The present economical analysis is based on a simplified model of micro distillery where the reduction on investment costs in based on technical data based on the possibility of the utilization of an hydrate alcohol with a higher water constant than the usual, i. e. around 85 0 GL. The engineering project of this plant eliminates all pumps, all the liquids (water, sugar cane, syrup and wine) are fed by gravity. The bagasse is considered a noble by-product and it is utilized in poultry industry as a substitute of wood dust. All the heat needs of the micro distillery are supplied by wood. (author)

  8. Pollution and economic growth in a model of overlapping generations

    International Nuclear Information System (INIS)

    Fisher, Eric O'N.; Van Marrewijk, Charles

    1994-01-01

    We analyze a model of overlapping generations in which clean air, a pure public consumption good, is used as a private input into production. Although production exhibits constant returns to scale, endogenous growth can occur because the economy has tWO sectors. In a laissez-faire equilibrium, there is no market for pollution rights, and firms appropriate clean air in an arbitrary manner. Growth occurs only if the marginal propensity to save is high enough and the asymptotic share of pollution in the investment sector is zero. Firms generate quasi-rents that are the value of pollution rights. These quasi-rents crowd out investment and slow economic growth. A laissez- faire equilibrium may not support Pareto optimal allocations, but a Pigouvian tax with lump-sum distribution of the resulting revenues does. Hence, a pollution lax yields a double dividend because it can increase both the static efficiency of the economy and its growth rate. 1 fig., 20 refs

  9. Empirical Analysis and Modeling of the Global Economic System

    Science.gov (United States)

    Duan, Wen-Qi; Sun, Bo-Liang

    2009-09-01

    In the global economic system, each economy stimulates the growth of its gross domestic products (GDP) by increasing its international trade. Using a fluctuation analysis of the flux data of GDP and foreign trade, we find that both GDP and foreign trade are dominated by external force and driven by each other. By excluding the impact of the associated trade dependency degree, GDP and the total volume of foreign trade collapse well into a power-law function. The economy's total trade volume scales with the number of trade partners, and it is distributed among its trade partners in an exponential form. The model which incorporated these empirical results can integrate the growth dynamics of GDP and the interplay dynamics between GDP and weighted international trade networks simultaneously.

  10. Modelling Technical and Economic Parameters in Selection of Manufacturing Devices

    Directory of Open Access Journals (Sweden)

    Naqib Daneshjo

    2017-11-01

    Full Text Available Sustainable science and technology development is also conditioned by continuous development of means of production which have a key role in structure of each production system. Mechanical nature of the means of production is complemented by controlling and electronic devices in context of intelligent industry. A selection of production machines for a technological process or technological project has so far been practically resolved, often only intuitively. With regard to increasing intelligence, the number of variable parameters that have to be considered when choosing a production device is also increasing. It is necessary to use computing techniques and decision making methods according to heuristic methods and more precise methodological procedures during the selection. The authors present an innovative model for optimization of technical and economic parameters in the selection of manufacturing devices for industry 4.0.

  11. Ecological theories and indicators in economic models of biodiversity loss and conservation: a critical review.

    NARCIS (Netherlands)

    Eppink, F.V.; van den Bergh, J.C.J.M.

    2007-01-01

    We evaluate how well environmental-economic models describe biodiversity loss and conservation issues. Four types of economic models turn out to dominate economic research into biodiversity conservation. For each of these, we assess the extent to which they integrate relevant ecological theories and

  12. Ecological Theories and Indicators in Economic Models of Biodiversity Loss and Conservation: A Critical Review

    NARCIS (Netherlands)

    Eppink, F.V.; van den Bergh, J.C.J.M.

    2007-01-01

    We evaluate how well environmental-economic models describe biodiversity loss and conservation issues. Four types of economic models turn out to dominate economic research into biodiversity conservation. For each of these, we assess the extent to which they integrate relevant ecological theories and

  13. Bio-economic modeling of water quality improvements using a dynamic applied general equilibrium approach

    NARCIS (Netherlands)

    Dellink, R.; Brouwer, R.; Linderhof, V.G.M.; Stone, K.

    2011-01-01

    An integrated bio-economic model is developed to assess the impacts of pollution reduction policies on water quality and the economy. Emission levels of economic activities to water are determined based on existing environmental accounts. These emission levels are built into a dynamic economic model

  14. A spatial-dynamic value transfer model of economic losses from a biological invasion

    Science.gov (United States)

    Thomas P. Holmes; Andrew M. Liebhold; Kent F. Kovacs; Betsy. Von Holle

    2010-01-01

    Rigorous assessments of the economic impacts of introduced species at broad spatial scales are required to provide credible information to policy makers. We propose that economic models of aggregate damages induced by biological invasions need to link microeconomic analyses of site-specific economic damages with spatial-dynamic models of value change associated with...

  15. Economic Crisis and Marital Problems in Turkey: Testing the Family Stress Model

    Science.gov (United States)

    Aytac, Isik A.; Rankin, Bruce H.

    2009-01-01

    This paper applied the family stress model to the case of Turkey in the wake of the 2001 economic crisis. Using structural equation modeling and a nationally representative urban sample of 711 married women and 490 married men, we tested whether economic hardship and the associated family economic strain on families resulted in greater marital…

  16. Recent advances in estimating nonlinear models with applications in economics and finance

    CERN Document Server

    Ma, Jun

    2013-01-01

    Featuring current research in economics, finance and management, this book surveys nonlinear estimation techniques and offers new methods and insights into nonlinear time series analysis. Covers Markov Switching Models for analyzing economics series and more.

  17. Sustainability and economics: The Adirondack Park experience, a forest economic-ecological model, and solar energy policy

    Science.gov (United States)

    Erickson, Jon David

    The long-term sustainability of human communities will depend on our relationship with regional environments, our maintenance of renewable resources, and our successful disengagement from nonrenewable energy dependence. This dissertation investigates sustainability at these three levels, following a critical analysis of sustainability and economics. At the regional environment level, the Adirondack Park of New York State is analyzed as a potential model of sustainable development. A set of initial and ongoing conditions are presented that both emerge from and support a model of sustainability in the Adirondacks. From these conditions, a clearer picture emerges of the definition of regional sustainability, consequences of its adoption, and lessons from its application. Next, an economic-ecological model of the northern hardwood forest ecosystem is developed. The model integrates economic theory and intertemporal ecological concepts, linking current harvest decisions with future forest growth, financial value, and ecosystem stability. The results indicate very different economic and ecological outcomes by varying opportunity cost and ecosystem recovery assumptions, and suggest a positive benefit to ecological recovery in the forest rotation decision of the profit maximizing manager. The last section investigates the motives, economics, and international development implications of renewable energy (specifically photovoltaic technology) in rural electrification and technology transfer, drawing on research in the Dominican Republic. The implications of subsidizing a photovoltaic market versus investing in basic research are explored.

  18. Economic modeling of the rational consumption of addictive substances.

    Science.gov (United States)

    Ferguson, Brian S

    2006-01-01

    This article gives an overview of the way economists model the decision to consume addictive commodities and reviews some of the relevant literature testing aspects of the model. It aims to answer the question of how it is that economists can speak of the consumption of addictive harmful commodities as a rational decision. Health economics treats the consumption of commodities that have beneficial (or harmful) effects on health, and therefore on utility or well-being, as intertemporal decisions with regard to investment decisions. In investment in health, the payoff to an action comes appreciably later than the action itself. The decision to consume harmful, and even addictive, commodities fits into the investment in health framework, with the benefit comes now, in the form of the pleasure derived from consuming them, and the costs, in terms of damage to the individual's health, comes later. The value that a person places on the future vs. the present is called time preference or subjective rate of time discounting, which represents the weight he places on the future relative to the present when he makes decisions that have future consequences. The more they discount the future, the more myopic they are and the more likely to undertake risky behaviors, including smoking or using drugs such as amphetamines or heroin, as well as dropping out of school or taking on high risk jobs.

  19. Modelling the economic impacts of addressing climate change

    International Nuclear Information System (INIS)

    2002-01-01

    This Power Point report presents highlights of the latest economic modelling of Canada's Kyoto commitment to address climate change. It presents framework assumptions and a snapshot under 4 scenarios. The objective of this report is to evaluate the national, sectoral, provincial and territorial impacts of the federal reference case policy package in which the emissions reduction target is 170 Mt from a business-as-usual scenario. The reference case policy package also includes 30 Mt of sinks from current packages of which 20 Mt are derived from the forestry sector and the remainder from agricultural sector. The report examined 4 scenarios based on 2 international carbon prices ($10 and $50) per tonne of carbon dioxide in 2010. The scenarios were also based on the fiscal assumptions that climate change initiatives and revenue losses would directly affect the governments' balances, or that the government balances are maintained by increasing personal income tax. A comparison of impacts under each of the 4 scenarios to 2010 was presented. The model presents impacts on GDP, employment, disposable income per household, and energy prices. 4 tabs., 4 figs

  20. Public sector administration of ecological economics systems using mediated modeling.

    Science.gov (United States)

    van den Belt, Marjan; Kenyan, Jennifer R; Krueger, Elizabeth; Maynard, Alison; Roy, Matthew Galen; Raphael, Ian

    2010-01-01

    In today's climate of government outsourcing and multiple stakeholder involvement in public sector management and service delivery, it is more important than ever to rethink and redesign the structure of how policy decisions are made, implemented, monitored, and adapted to new realities. The traditional command-and-control approach is now less effective because an increasing amount of responsibility to deliver public goods and services falls on networks of nongovernment agencies. Even though public administrators are seeking new decision-making models in an increasingly more complex environment, the public sector currently only sparsely utilizes Mediated Modeling (MM). There is growing evidence, however, that by employing MM and similar tools, public interest networks can be better equipped to deal with their long-term viability while maintaining the short-term needs of their clients. However, it may require a shift in organizational culture within and between organizations to achieve the desired results. This paper explores the successes and barriers to implementing MM and similar tools in the public sector and offers insights into utilizing them through a review of case studies and interdisciplinary literature. We aim to raise a broader interest in MM and similar tools among public sector administrators at various administrative levels. We focus primarily, but not exclusively, on those cases operating at the interface of ecology and socio-economic systems.

  1. Biomass to Hydrogen Production Detailed Design and Economics Utilizing the Battelle Columbus Laboratory Indirectly-Heated Gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Spath, P.; Aden, A.; Eggeman, T.; Ringer, M.; Wallace, B.; Jechura, J.

    2005-05-01

    This analysis developed detailed process flow diagrams and an Aspen Plus{reg_sign} model, evaluated energy flows including a pinch analysis, obtained process equipment and operating costs, and performed an economic evaluation of two process designs based on the syngas clean up and conditioning work being performed at NREL. One design, the current design, attempts to define today's state of the technology. The other design, the goal design, is a target design that attempts to show the effect of meeting specific research goals.

  2. Economic models and having children: some evidence from Kwahu, Ghana.

    Science.gov (United States)

    Oppong, C; Bleek, W

    1982-01-01

    This discussion outlines briefly some of the main features of economic models of rational decision making with regard to fertility which focus on the perceived costs and benefits of parenthood, noting the findings of several Ghanaian studies which have tried to link changing patterns of costs and benefits involved in kin and conjugal family ties with changes in fertility and parental role expectations. Procreation and its context in a rural Kwahu town of southern Ghana in the early 1970s is then described and illustration is included of how a "cost benefit" analysis of pregnancy termination and child bearing in this society illuminates why, although induced abortion rates appeared high, there was little noticeable shift to much lower fertility values or achievements than those traditionally admired. The data on the families of Ghanaian salary earners indicated the usefulness of an economic approach, with attention given to the allocation of scarce resources through the essentially rational choices of individual parents, continually trying to avoid or alleviate the effects of role strain and conflict. They also illustrate the need for household economists' models to take more sophisticated account of variables such as the openness or closure of the conjugal family in various areas of its operation and the need to treat the degrees of jointness of the conjugal role relationship in different areas as crucial variables. The town of the research is a typical "home town," which means that it constitutes the base from which people depart, either to an urban center where they take up trading or look for other employment, or to a farming settlement where they may spend from a few months to several years clearing new land or harvesting crops. The data from Kwahu reveal that the people are struggling to improve their lot in an uncertain and changing context in which lineage support is not guaranteed, marriage is unstable and children often leave their parents at an early age

  3. Technological, economic and environmental evaluation of rice husk gasification in a biorefinery context to produce indirect energy as jet fuel

    Directory of Open Access Journals (Sweden)

    Juan Jacobo Jaramillo Obando

    2017-09-01

    Full Text Available Higher alcohol 1-octanol was evaluated as jet fuel potential. The synthesis of the 1-octanol was modeled and the technological, economic and environmental evaluation of the global production process of the rice husk gasification was performed. The best operating conditions to 1-octanol synthesis were obtained in packed bed reactor PBR using Matlab software. Mass and energy balances were calculated using Aspen Plus Software. Economic assessment was developed using Aspen Process Economic Analyzer Software. Environmental impact evaluation was carried out using the waste reduction algorithm WAR. Process yield was 0.83 kg of 1-Octanol by kg of rice husk. Total production cost obtained was USD 0.957 per kg of 1-octanol and the total PEI of product leave the system is 0.08142 PEI/kg with a PEI mitigated of 12.97 PEI/kg. Production process of high alcohols from rice husk shows a high potential technological, economical and environmental as a sustainable industry at take advantage of an agroindustrial residue and transformed in products with added value and energy. 1-octanol as jet fuel has a potential but need to be more studied for direct use in jet motors.

  4. The Budget and Economic Outlook: Fiscal Years 2007 to 2016

    Science.gov (United States)

    2006-01-01

    of Labor Statistics; Federal Reserve Board; Aspen Publishers, Inc., Blue Chip Economic Indicators (January 10, 2005); Council of Economic Advisers...Partnership Act 09/30/08 n.a. n.a. n.a. * * * * * * * * -0.1 -0.2 Biodiesel Credits 12/31/08 n.a. n.a. n.a. -0.1 -0.1 -0.2 -0.2 -0.2 -0.2 -0.2 -0.3 -0.4...monthly by Aspen Publishers, Inc. book depreciation: See depreciation. book profits: Profits calculated using book (or tax) de- preciation and standard

  5. Modeling the Development of Vocational Competence: A Psychometric Model for Economic Domains

    Science.gov (United States)

    Klotz, Viola Katharina; Winther, Esther; Festner, Dagmar

    2015-01-01

    This article discusses the development of vocational competence through economic vocational educational training (VET) from a theoretical and psychometric perspective. Most assessment and competence models tend to adopt a state perspective toward assessments of competence and carve out different structures of competence for diverse vocational…

  6. Regional Economic Development Impact Model: Phase I Study.

    Science.gov (United States)

    1985-11-01

    the technical coefficients were suggested by Walras as early as the late nineteenth century’ [ Walras (33)]. Recently, Hudson and Jorgenson...Economics and Statistics, August, 1957. 33. Walras , L., Elements of Pure Economics, (English Edition), George Allen and Urwin, London, 1954. 6 ,. 69

  7. A Panel Threshold Model of Tourism Specialization and Economic Development

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); T. Khamkaew (Tanchanok); M.J. McAleer (Michael)

    2009-01-01

    textabstractThe significant impact of international tourism in stimulating economic growth is especially important from a policy perspective. For this reason, the relationship between international tourism and economic growth would seem to be an interesting empirical issue. In particular, if there

  8. A Simple Model of Entrepreneurship for Principles of Economics Courses

    Science.gov (United States)

    Gunter, Frank R.

    2012-01-01

    The critical roles of entrepreneurs in creating, operating, and destroying markets, as well as their importance in driving long-term economic growth are still generally either absent from principles of economics texts or relegated to later chapters. The primary difficulties in explaining entrepreneurship at the principles level are the lack of a…

  9. Modeling the economics and market adoption of distributed power generation

    International Nuclear Information System (INIS)

    Maribu, Karl Magnus

    2006-01-01

    After decades of power generating units increasing in size, there is currently a growing focus on distributed generation, power generation close to energy loads. Investments in large-scale units have been driven by economy of scale, but recent technological improvements on small generating plants have made it possible to exploit the benefits of local power generation to a larger extent than previously. Distributed generation can improve power system efficiency because heat can be recovered from thermal units to supply heat and thermally activated cooling, and because small-scale renewables have a promising end-user market. Further benefits of distributed generation include improved reliability, deferral of often controversial and costly grid investments and reduction of grid losses. The new appeal of small-scale power generation means that there is a need for new tools to analyze distributed generation, both from a system perspective and from the perspective of potential developers. In this thesis, the focus is on the value of power generation for end-users. The thesis identifies how an end-user can find optimal distributed generation systems and investment strategies under a variety of economic and regulatory scenarios. The final part of the thesis extends the analysis with a bottom up model of how the economics of distributed generation for a representative set of building types can transfer to technology diffusion in a market. Four separate research papers make up the thesis. In the first paper, Optimal Investment Strategies in Decentralized Renewable Power Generation under Uncertainty, a method for evaluation of investments in renewable power units under price uncertainty is presented. It is assumed the developer has a building with an electricity load and a renewable power resource. The case study compares a set of wind power systems with different capacity and finds that capacity depends on the electricity price and that there under uncertain prices can be a

  10. Economic analysis of open space box model utilization in spacecraft

    Science.gov (United States)

    Mohammad, Atif F.; Straub, Jeremy

    2015-05-01

    It is a known fact that the amount of data about space that is stored is getting larger on an everyday basis. However, the utilization of Big Data and related tools to perform ETL (Extract, Transform and Load) applications will soon be pervasive in the space sciences. We have entered in a crucial time where using Big Data can be the difference (for terrestrial applications) between organizations underperforming and outperforming their peers. The same is true for NASA and other space agencies, as well as for individual missions and the highly-competitive process of mission data analysis and publication. In most industries, conventional opponents and new candidates alike will influence data-driven approaches to revolutionize and capture the value of Big Data archives. The Open Space Box Model is poised to take the proverbial "giant leap", as it provides autonomic data processing and communications for spacecraft. We can find economic value generated from such use of data processing in our earthly organizations in every sector, such as healthcare, retail. We also can easily find retailers, performing research on Big Data, by utilizing sensors driven embedded data in products within their stores and warehouses to determine how these products are actually used in the real world.

  11. A Behavioral Economic Model of Alcohol Advertising and Price.

    Science.gov (United States)

    Saffer, Henry; Dave, Dhaval; Grossman, Michael

    2016-07-01

    This paper presents a new empirical study of the effects of televised alcohol advertising and alcohol price on alcohol consumption. A novel feature of this study is that the empirical work is guided by insights from behavioral economic theory. Unlike the theory used in most prior studies, this theory predicts that restriction on alcohol advertising on TV would be more effective in reducing consumption for individuals with high consumption levels but less effective for individuals with low consumption levels. The estimation work employs data from the National Longitudinal Survey of Youth, and the empirical model is estimated with quantile regressions. The results show that advertising has a small positive effect on consumption and that this effect is relatively larger at high consumption levels. The continuing importance of alcohol taxes is also supported. Education is employed as a proxy for self-regulation, and the results are consistent with this assumption. The key conclusion is that restrictions on alcohol advertising on TV would have a small negative effect on drinking, and this effect would be larger for heavy drinkers. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Risk-trading in flood management: An economic model.

    Science.gov (United States)

    Chang, Chiung Ting

    2017-09-15

    Although flood management is no longer exclusively a topic of engineering, flood mitigation continues to be associated with hard engineering options. Flood adaptation or the capacity to adapt to flood risk, as well as a demand for internalizing externalities caused by flood risk between regions, complicate flood management activities. Even though integrated river basin management has long been recommended to resolve the above issues, it has proven difficult to apply widely, and sometimes even to bring into existence. This article explores how internalization of externalities as well as the realization of integrated river basin management can be encouraged via the use of a market-based approach, namely a flood risk trading program. In addition to maintaining efficiency of optimal resource allocation, a flood risk trading program may also provide a more equitable distribution of benefits by facilitating decentralization. This article employs a graphical analysis to show how flood risk trading can be implemented to encourage mitigation measures that increase infiltration and storage capacity. A theoretical model is presented to demonstrate the economic conditions necessary for flood risk trading. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. EUROPEAN SOCIAL MODEL.COMPETITIVE ADVANTAGE OR ECONOMIC HANDICAP

    Directory of Open Access Journals (Sweden)

    Iovitu Mariana

    2010-07-01

    Full Text Available “Corporative social responsibility” (CSR represents equally a very actual debate, but also an appraisal criteria of the dynamic of eco-social integration quality process at European level. Especially that the protection need is demanded by the current economic crisis. This concept is meant to combine the position, attitude and behaviour of the trade-unions with the interests of employer’s organisations in search of possible influential mechanisms of the competitive advantage at European level. Due to the current economic crisis, the implications on the labour force market are causing an explainable anxiety. The attention of the decision takers is oriented towards joining the objectives “social well being with economic well being” in view of an expected economic come back. This approach proves a significant change at the level of economic and social policies within the European Union.

  14. The South Korean Model of Political and Economic Development: Economic Aspects.

    Science.gov (United States)

    1983-10-01

    chaebol , a Korean version of the earlier Japanese zaibatsu) also promote the increases in scale that reduce absorption. In mining and manufacturing...industry projects, and the chaebol , or large conglomerate enterprises. The governent’s activity or inactivity in economic affairs is mainly significant in

  15. Modeling economic growth fuelled by science and technology

    Directory of Open Access Journals (Sweden)

    Leonardo Costa Ribeiro

    2010-06-01

    Full Text Available This paper suggests a simulation model to investigate how science and technology fuel economic growth. This model is built upon a synthesis of technological capabilities represented by national innovation systems. This paper gathers data of papers and patents for 183 countries between 1999 and 2003, as well as GDP and population for 2003. These data show a strong correlation between science, technology and income. Three simulation exercises are performed. Feeding our algorithm with data for population, patents and scientific papers, we obtain the world income distribution. These results support our conjecture on the role of science and technology as sources of the wealth of nations.Este artigo propõe um modelo de simulação para investigar a contribuição da ciência e da tecnologia para o crescimento econômico. O ponto de partida são os sistemas nacionais de inovação, um conceito que sintetiza a capacitação tecnológica das nações. Desta forma, o modelo pode preservar simplicidade e parcimônia. Os dados coletados (patentes, artigos e PIB e população, para 183 países indicam uma forte correlação entre ciência, tecnologia e renda. Três exercícios com simulações são realizados para diversos momentos do tempo, mostrando a progressiva aderência do modelo a essas variáveis tecnológicas.

  16. The future of food demand: understanding differences in global economic models

    NARCIS (Netherlands)

    Valin, H.; Sands, R.D.; Mensbrugghe, van der D.; Nelson, G.; Ahammad, H.; Blanc, E.; Bodirsky, B.; Fujimori, S.; Hasegawa, T.; Havlik, P.; Heyhoe, E.; Kyle, P.; Mason d'Croz, D.; Paltsev, S.; Rolinksi, S.; Tabeau, A.A.; Meijl, van J.C.M.; Lampe, von M.; Willenbockel, D.

    2014-01-01

    Understanding the capacity of agricultural systems to feed the world population under climate change requires projecting future food demand. This article reviews demand modeling approaches from 10 global economic models participating in the Agricultural Model Intercomparison and Improvement Project

  17. The model of localized business community economic development under limited financial resources: computer model and experiment

    Directory of Open Access Journals (Sweden)

    Berg Dmitry

    2016-01-01

    Full Text Available Globalization processes now affect and are affected by most of organizations, different type resources, and the natural environment. One of the main restrictions initiated by these processes is the financial one: money turnover in global markets leads to its concentration in the certain financial centers, and local business communities suffer from the money lack. This work discusses the advantages of complementary currency introduction into a local economics. By the computer simulation with the engineered program model and the real economic experiment it was proved that the complementary currency does not compete with the traditional currency, furthermore, it acts in compliance with it, providing conditions for the sustainable business community development.

  18. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Directory of Open Access Journals (Sweden)

    Philipp Emanuel Hirsch

    Full Text Available Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity. Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  19. A Hydro-Economic Model for Water Level Fluctuations: Combining Limnology with Economics for Sustainable Development of Hydropower

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands. PMID:25526619

  20. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  1. A Study on the development of macro environmental economic model(I)

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Young Keun; Han, Min Jung [Korea Environment Institute, Seoul (Korea)

    1998-12-01

    This study is the first year study of the two year research project for developing a macro environmental economic model to analyze environment and economics. By using this model, the economic effects of investment on pollution reduction and on energy conservation are analyzed. Also, a comprehensive modeling of analyzing effects of environmental tax, reduction on greenhouse gas emission, and problems on foreign exchange on environment and economy is a main goal of this study. It is planned to develop a simulation program for the estimation of model and policies using environmental and economic data. 126 refs., 2 figs., 5 tabs.

  2. Growth structure and environment. 6 contributions to the macro economic model development

    International Nuclear Information System (INIS)

    Wier, Mette

    1998-04-01

    This thesis comprises 6 papers on the application of macro economic models to environmental problems. Interactions between the economic and the ecological models are elucidated and a description is given of a possible systematization of of the environmental-economic cycle within a macro economic model. Economic and technological limitations affecting the potential environmental advantages are discussed. In the second part of the thesis the general interdependence of production and consumption, and the various forms of environmental stress is analyzed. For this purpose an environment-related input-output model is presented, where for each industry there are given emissions and/or consumption of natural resources (so-called environmental coefficients), which are likely to originate from the activities of this industry. As examples of macro economic modelling,the nitrogen cycle in Denmark, environmental effects of consumer choice, use of building materials and emission due to energy generation and consumption etc. are analyzed. (EG) 146 refs

  3. Thinning Pole-Sized Aspen Has no Effect on Number of Veneer Trees or Total Yield

    Science.gov (United States)

    Bryce E. Schlaegel; Stanley B. Ringlod

    1971-01-01

    Thinning 37-year-old aspen in north central Minnesota did not increase either total volume production or the number of veneer-sized trees after 10 years. Thinning is not recommended for stands nearing rotation age.

  4. Best Practices Case Study: Shaw Construction Burlingame Ranch Ph.1, Aspen, CO

    Energy Technology Data Exchange (ETDEWEB)

    Pacific Northwest National Laboratory & Oak Ridge National Laboratory

    2010-12-01

    Shaw Construction built 84 energy efficient, affordable condominiums forthe City of Aspen that achieved HERS scores of less than 62 with help from Building America’s research team lead Building Science Corporation.

  5. Elevated CO2 response of photosynthesis depends on ozone concentration in aspen

    Science.gov (United States)

    Asko Noormets; Olevi Kull; Anu Sober; Mark E. Kubiske; David F. Karnosky

    2010-01-01

    The effect of elevated CO2 and O3 on apparent quantum yield (ø), maximum photosynthesis (Pmax), carboxylation efficiency (Vcmax) and electron transport capacity (Jmax) at different canopy locations was studied in two aspen (Populus...

  6. Mercuric Chloride Effects on Root Water Transport in Aspen Seedlings.

    Science.gov (United States)

    Wan; Zwiazek

    1999-11-01

    HgCl(2) (0.1 mM) reduced pressure-induced water flux and root hydraulic conductivity in the roots of 1-year-old aspen (Populus tremuloides Michx.) seedlings by about 50%. The inhibition was reversed with 50 mM mercaptoethanol. Mercurial treatment reduced the activation energy of water transport in the roots from 10.82 +/- 0.700 kcal mol(-1) to 6.67 +/- 0.193 kcal mol(-1) when measured over the 4 degrees C to 25 degrees C temperature range. An increase in rhodamine B concentration in the xylem sap of mercury-treated roots suggested a decrease in the symplastic transport of water. However, the apoplastic pathway in both control and mercury-treated roots constituted only a small fraction of the total root water transport. Electrical conductivity and osmotic potentials of the expressed xylem sap suggested that 0.1 mM HgCl(2) and temperature changes over the 4 degrees C to 25 degrees C range did not induce cell membrane leakage. The 0.1 mM HgCl(2) solution applied as a root drench severely reduced stomatal conductance in intact plants, and this reduction was partly reversed by 50 mM mercaptoethanol. In excised shoots, 0.1 mM HgCl(2) did not affect stomatal conductance, suggesting that the signal that triggered stomatal closure originated in the roots. We suggest that mercury-sensitive processes in aspen roots play a significant role in regulating plant water balance by their effects on root hydraulic conductivity.

  7. Impact of ozone on understory plants of the aspen zone

    Energy Technology Data Exchange (ETDEWEB)

    Harward, M.R.; Treshow, M.

    1971-01-01

    The purpose of this study was to learn how ozone might affect the growth and reproduction of understory species of the aspen community, and thereby influence its stability and composition. Plants of 15 representative species of the aspen community were grown in chambers and fumigated 4 hours each day, 5 days per week throughout their growing seasons. These included: Achillea millifolium, Chenopodium album, Chenopodium fremontii, Cruciferae sp., Descurainia pinnata, Descurainia sp., Geranium fremontii, Isatis tinctoria, Ligusticum porteri, Lepidium virginicum, Madia glomerata, Polygonum aviculare, Polygonum douglasii, Phacelia heterophylla, Viola italica. Plants were exposed to 30 pphm, 15 pphm, ambient air reaching 5-7 pphm for 2 hours per day, and filtered air. The study was repeated for 3 seasons. Ambient air caused a significant reduction of total plant weight only of Lepidium virginicum. Six species produced fruit and seeds. At 15 pphm, seed production by Madia glomerata and Polygonum douglasii was significantly reduced. At 30 pphm, seed production was also reduced in Polygonum aviculare and Lepidium virginicum. The two most significant conclusions to emerge from the study were first that several species were more sensitive to ozone than might have been suspected. Second, this sensitivity varied sufficiently that major shifts in community composition would be probable following only a year or two of exposure. More tolerant species have no doubt already become dominant over more sensitive species in natural plant communities exposed to elevated ozone concentrations. It must be stressed that the species studied did not necessarily represent the most ozone sensitive members of the community, or the most tolerant.

  8. Special Issue on Using Econometrics for Assessing Economic Models

    DEFF Research Database (Denmark)

    Juselius, Katarina

    2009-01-01

    Two methodological approaches to empirical economics which are labelled ‘theory first' versus ‘reality first' are introduced building the background for the discussion of the individual contributions to this special issue....

  9. Review of regional economic models with special reference to labor impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ferris, G.; Mason, B.

    1979-06-01

    This paper reviews several regional economic models and examines the capabilities of these models for assessing the total employment impacts of solar energy adoption. Five generic analytic methods are discussed: economic base analysis, shift-share analysis, demographic-economic interaction models, input-output analysis, and industrial location analysis. Ten regional models incorporating some aspect of these methods are reviewed. From the model review, the conclusion is drawn that there is no single model that fits all of the necessary criteria for planned research efforts. Models that appear to hold promise are the Economic Activity Analysis (EAA) Model, the Regional Industrial Multipliers System (RIMS), the Multiregion, Multi-industry (MRMI) Model, and the MULTIREGION model.

  10. Design, fabrication, operation and Aspen simulation of oil shale pyrolysis and biomass gasification process using a moving bed downdraft reactor

    Science.gov (United States)

    Golpour, Hassan

    Energy is the major facilitator of the modern life. Every developed and developing economy requires access to advanced sources of energy to support its growth and prosperity. Declining worldwide crude oil reserves and increasing energy needs has focused attention on developing existing unconventional fossil fuels like oil shale and renewable resources such as biomass. Sustainable, renewable and reliable resources of domestically produced biomass comparing to wind and solar energy is a sensible motivation to establish a small-scale power plant using biomass as feed to supply electricity demand and heat for rural development. The work in Paper I focuses on the possibility of water pollution from spent oil shale which should be studied before any significant commercial production is attempted. In Paper II, the proposed Aspen models for oil shale pyrolysis is to identify the key process parameters for the reactor and optimize the rate of production of syncrude from oil shale. The work in Paper III focuses on (1) Design and operation of a vertical downdraft reactor, (2) Establishing an optimum operating methodology and parameters to maximize syngas production through process testing. Finally in Paper IV, a proposed Aspen model for biomass gasification simulates a real biomass gasification system discussed in Paper III.

  11. A Critical Review of Model-Based Economic Studies of Depression: Modelling Techniques, Model Structure and Data Sources

    OpenAIRE

    Hossein Haji Ali Afzali; Jonathan Karnon; Jodi Gray

    2012-01-01

    Depression is the most common mental health disorder and is recognized as a chronic disease characterized by multiple acute episodes/relapses. Although modelling techniques play an increasingly important role in the economic evaluation of depression interventions, comparatively little attention has been paid to issues around modelling studies with a focus on potential biases. This, however, is important as different modelling approaches, variations in model structure and input parameters may ...

  12. Modeling the economic costs of disasters and recovery: analysis using a dynamic computable general equilibrium model

    Science.gov (United States)

    Xie, W.; Li, N.; Wu, J.-D.; Hao, X.-L.

    2014-04-01

    Disaster damages have negative effects on the economy, whereas reconstruction investment has positive effects. The aim of this study is to model economic causes of disasters and recovery involving the positive effects of reconstruction activities. Computable general equilibrium (CGE) model is a promising approach because it can incorporate these two kinds of shocks into a unified framework and furthermore avoid the double-counting problem. In order to factor both shocks into the CGE model, direct loss is set as the amount of capital stock reduced on the supply side of the economy; a portion of investments restores the capital stock in an existing period; an investment-driven dynamic model is formulated according to available reconstruction data, and the rest of a given country's saving is set as an endogenous variable to balance the fixed investment. The 2008 Wenchuan Earthquake is selected as a case study to illustrate the model, and three scenarios are constructed: S0 (no disaster occurs), S1 (disaster occurs with reconstruction investment) and S2 (disaster occurs without reconstruction investment). S0 is taken as business as usual, and the differences between S1 and S0 and that between S2 and S0 can be interpreted as economic losses including reconstruction and excluding reconstruction, respectively. The study showed that output from S1 is found to be closer to real data than that from S2. Economic loss under S2 is roughly 1.5 times that under S1. The gap in the economic aggregate between S1 and S0 is reduced to 3% at the end of government-led reconstruction activity, a level that should take another four years to achieve under S2.

  13. Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L..

    Directory of Open Access Journals (Sweden)

    Kathryn M Robinson

    Full Text Available We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

  14. Genetic variation of hydraulic and wood anatomical traits in hybrid poplar and trembling aspen.

    Science.gov (United States)

    Schreiber, Stefan G; Hacke, Uwe G; Hamann, Andreas; Thomas, Barb R

    2011-04-01

    Intensive forestry systems and breeding programs often include either native aspen or hybrid poplar clones, and performance and trait evaluations are mostly made within these two groups. Here, we assessed how traits with potential adaptive value varied within and across these two plant groups. Variation in nine hydraulic and wood anatomical traits as well as growth were measured in selected aspen and hybrid poplar genotypes grown at a boreal planting site in Alberta, Canada. Variability in these traits was statistically evaluated based on a blocked experimental design. We found that genotypes of trembling aspen were more resistant to cavitation, exhibited more negative water potentials, and were more water-use-efficient than hybrid poplars. Under the boreal field test conditions, which included major regional droughts, height growth was negatively correlated with branch vessel diameter (Dv ) in both aspen and hybrid poplars and differences in Dv were highly conserved in aspen trees from different provenances. Differences between the hybrid poplars and aspen provenances suggest that these two groups employ different water-use strategies. The data also suggest that vessel diameter may be a key trait in evaluating growth performance in a boreal environment. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  15. Climate change feedback on economic growth: Explorations with a dynamic general equilibrium model

    OpenAIRE

    Eboli, Fabio; Parrado, Ramiro; Roson, Roberto

    2009-01-01

    Human-generated greenhouse gases depend on the level of economic activity. Therefore, most climate change studies are based on models and scenarios of economic growth. Economic growth itself, however, is likely to be affected by climate change impacts. These impacts affect the economy in multiple and complex ways: changes in productivity, resource endowments, production and consumption patterns. We use a new dynamic, multi-regional Computable General Equilibrium (CGE) model of the world econo...

  16. Modeling the economic outcomes of immuno-oncology drugs: alternative model frameworks to capture clinical outcomes

    Directory of Open Access Journals (Sweden)

    Gibson EJ

    2018-03-01

    Full Text Available EJ Gibson,1 N Begum,1 I Koblbauer,1 G Dranitsaris,2 D Liew,3 P McEwan,4 AA Tahami Monfared,5,6 Y Yuan,7 A Juarez-Garcia,7 D Tyas,8 M Lees9 1Wickenstones Ltd, Didcot, UK; 2Augmentium Pharma Consulting Inc, Toronto, ON, Canada; 3Department of Epidemiology and Preventive Medicine, Alfred Hospital, Monash University, Melbourne, VIC, Australia; 4Health Economics and Outcomes Research Ltd, Cardiff, UK; 5Bristol-Myers Squibb Canada, Saint-Laurent, QC Canada; 6Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC, Canada; 7Bristol-Myers Squibb, Princeton, NJ, USA; 8Bristol-Myers Squibb, Uxbridge, UK; 9Bristol-Myers Squibb, Rueil-Malmaison, France Background: Economic models in oncology are commonly based on the three-state partitioned survival model (PSM distinguishing between progression-free and progressive states. However, the heterogeneity of responses observed in immuno-oncology (I-O suggests that new approaches may be appropriate to reflect disease dynamics meaningfully. Materials and methods: This study explored the impact of incorporating immune-specific health states into economic models of I-O therapy. Two variants of the PSM and a Markov model were populated with data from one clinical trial in metastatic melanoma patients. Short-term modeled outcomes were benchmarked to the clinical trial data and a lifetime model horizon provided estimates of life years and quality adjusted life years (QALYs. Results: The PSM-based models produced short-term outcomes closely matching the trial outcomes. Adding health states generated increased QALYs while providing a more granular representation of outcomes for decision making. The Markov model gave the greatest level of detail on outcomes but gave short-term results which diverged from those of the trial (overstating year 1 progression-free survival by around 60%. Conclusion: Increased sophistication in the representation of disease dynamics in economic models

  17. The role of decision analytic modeling in the health economic assessment of spinal intervention.

    Science.gov (United States)

    Edwards, Natalie C; Skelly, Andrea C; Ziewacz, John E; Cahill, Kevin; McGirt, Matthew J

    2014-10-15

    Narrative review. To review the common tenets, strengths, and weaknesses of decision modeling for health economic assessment and to review the use of decision modeling in the spine literature to date. For the majority of spinal interventions, well-designed prospective, randomized, pragmatic cost-effectiveness studies that address the specific decision-in-need are lacking. Decision analytic modeling allows for the estimation of cost-effectiveness based on data available to date. Given the rising demands for proven value in spine care, the use of decision analytic modeling is rapidly increasing by clinicians and policy makers. This narrative review discusses the general components of decision analytic models, how decision analytic models are populated and the trade-offs entailed, makes recommendations for how users of spine intervention decision models might go about appraising the models, and presents an overview of published spine economic models. A proper, integrated, clinical, and economic critical appraisal is necessary in the evaluation of the strength of evidence provided by a modeling evaluation. As is the case with clinical research, all options for collecting health economic or value data are not without their limitations and flaws. There is substantial heterogeneity across the 20 spine intervention health economic modeling studies summarized with respect to study design, models used, reporting, and general quality. There is sparse evidence for populating spine intervention models. Results mostly showed that interventions were cost-effective based on $100,000/quality-adjusted life-year threshold. Spine care providers, as partners with their health economic colleagues, have unique clinical expertise and perspectives that are critical to interpret the strengths and weaknesses of health economic models. Health economic models must be critically appraised for both clinical validity and economic quality before altering health care policy, payment strategies, or

  18. Modelling the economic consequences of Marine Protected Areas using the BEMCOM model

    DEFF Research Database (Denmark)

    Hoff, A.; Andersen, J.L.; Christensen, Asbjørn

    2013-01-01

    the question ‘what’s best?’, i.e. finds the overall optimal effort allocation, from an economic point of view, between multiple harvesting fleets fishing under a subset of restrictions on catches and effort levels. The BEMCOM model is described and applied to the case of the Danish sandeel fishery in the North...... reliable estimates of the effect of MPAs, and can thus be a valuable tool when deciding where to locate MPA...

  19. Influence of stocking, site quality, stand age, low-severity canopy disturbance, and forest composition on sub-boreal aspen mixedwood carbon stocks

    Science.gov (United States)

    Reinikainen, Michael; D’Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Low-severity canopy disturbance presumably influences forest carbon dynamics during the course of stand development, yet the topic has received relatively little attention. This is surprising because of the frequent occurrence of such events and the potential for both the severity and frequency of disturbances to increase as a result of climate change. We investigated the impacts of low-severity canopy disturbance and average insect defoliation on forest carbon stocks and rates of carbon sequestration in mature aspen mixedwood forests of varying stand age (ranging from 61 to 85 years), overstory composition, stocking level, and site quality. Stocking level and site quality positively affected the average annual aboveground tree carbon increment (CAAI), while stocking level, site quality, and stand age positively affected tree carbon stocks (CTREE) and total ecosystem carbon stocks (CTOTAL). Cumulative canopy disturbance (DIST) was reconstructed using dendroecological methods over a 29-year period. DIST was negatively and significantly related to soil carbon (CSOIL), and it was negatively, albeit marginally, related to CTOTAL. Minima in the annual aboveground carbon increment of trees (CAI) occurred at sites during defoliation of aspen (Populus tremuloides Michx.) by forest tent caterpillar (Malacosoma disstria Hubner), and minima were more extreme at sites dominated by trembling aspen than sites mixed with conifers. At sites defoliated by forest tent caterpillar in the early 2000s, increased sequestration by the softwood component (Abies balsamea (L.) Mill. and Picea glauca (Moench) Voss) compensated for overall decreases in CAI by 17% on average. These results underscore the importance of accounting for low-severity canopy disturbance events when developing regional forest carbon models and argue for the restoration and maintenance of historically important conifer species within aspen mixedwoods to enhance stand-level resilience to disturbance agents and maintain

  20. Wood properties of trembling aspen and paper birch after 5 years of exposure to elevated concentrations of CO2 and O3

    International Nuclear Information System (INIS)

    Kostiainen, K.; Kaakinen, S.; Warsta, E.; Vapaavuori, E.; Kubiske, M.E.; Nelson, N.D.; Sober, J.; Karnosky, D.F.; Saranpaa, P.

    2008-01-01

    This study examined the interactive effects of increased levels of carbon dioxide (CO 2 ) and ozone (O 3 ) on the radial growth, wood chemistry, and structure of 5 year old trembling aspen clones and paper birch trees. Samples were collected from the Aspen Free Air CO 2 Enrichment (FACE) experiment in Wisconsin. The aim of the study was to assess whether the responses of wood properties after 3 years of exposure were maintained as the canopies closed after 5 years. Annual rings were examined in order to determine the responses of the species to elevated CO 2 and O 3 were the same; to determine if slow-growing aspen genotypes became suppressed by the dominant genotypes in different treatments; and (3) to assess if the positive effects of elevated CO 2 counteracted the negative effects of O 3 . Effects were analyzed by mixed-model analysis of variance (ANOVA). Results of the study showed that the wood properties of both species were both altered in response to the increased O 3 and CO 2 levels. Elevated CO 2 decreased uronic acids in the trembling aspens and increased stem diameter. Acid-soluble lignin concentrations decreased with elevated O 3 and decreased vessel lumen diameter. Increased levels of O 3 raised concentrations of acetone-soluble extractives in paper birch. Elevated CO 2 and O 3 levels increased starch concentrations. It was concluded that wood properties after 5 years of fumigation differed significantly from properties reported in experiments with saplings examined after 3 years of fumigation. 48 refs., 3 tabs., 2 figs

  1. Economic efficiency versus social equality? The U.S. liberal model versus the European social model.

    Science.gov (United States)

    Navarro, Vicente; Schmitt, John

    2005-01-01

    This article begins by challenging the widely held view in neoliberal discourse that there is a necessary trade-off between higher efficiency and lower reduction of inequalities: the article empirically shows that the liberal, U.S. model has been less efficient economically (slower economic growth, higher unemployment) than the social model in existence in the European Union and in the majority of its member states. Based on the data presented, the authors criticize the adoption of features of the liberal model (such as deregulation of their labor markets, reduction of public social expenditures) by some European governments. The second section analyzes the causes for the slowdown of economic growth and the increase of unemployment in the European Union--that is, the application of monetarist and neoliberal policies in the institutional frame of the European Union, including the Stability Pact, the objectives and modus operandi of the European Central Bank, and the very limited resources available to the European Commission for stimulating and distributive functions. The third section details the reasons for these developments, including (besides historical considerations) the enormous influence of financial capital in the E.U. institutions and the very limited democracy. Proposals for change are included.

  2. AN ECONOMIC-AND-MATHEMATICAL MODEL OF OPENING PARAMETERS OF PREPARATION WORKS

    Directory of Open Access Journals (Sweden)

    A. H. Vahonova

    2010-03-01

    Full Text Available We propose an economic-and-mathematical model of opening and preparation of mine field based on the graph theory. The model is optimized by the factor of minimum amounts of conducting the preparation underground works.

  3. Status Report on Modeling and Analysis of Small Modular Reactor Economics

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Thomas J [ORNL; Hale, Richard Edward [ORNL; Moses, Rebecca J [ORNL

    2013-04-01

    This report describes the work performed to generate the model for SMR economic analysis. The model is based on the G4-ECONS calculation tool developed for the Generation IV International Forum (GIF).

  4. Petroleum Refinery Jobs and Economic Development Impact (JEDI) Model User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Marshall [MRG and Associates, Nevada City, CA (United States)

    2013-12-31

    The Jobs and Economic Development Impact (JEDI) models, developed through the National Renewable Energy Laboratory (NREL), are user-friendly tools utilized to estimate the economic impacts at the local level of constructing and operating fuel and power generation projects for a range of conventional and renewable energy technologies. The JEDI Petroleum Refinery Model User Reference Guide was developed to assist users in employing and understanding the model. This guide provides information on the model's underlying methodology, as well as the parameters and references used to develop the cost data utilized in the model. This guide also provides basic instruction on model add-in features, operation of the model, and a discussion of how the results should be interpreted. Based on project-specific inputs from the user, the model estimates job creation, earning and output (total economic activity) for a given petroleum refinery. This includes the direct, indirect and induced economic impacts to the local economy associated with the refinery's construction and operation phases. Project cost and job data used in the model are derived from the most current cost estimations available. Local direct and indirect economic impacts are estimated using economic multipliers derived from IMPLAN software. By determining the regional economic impacts and job creation for a proposed refinery, the JEDI Petroleum Refinery model can be used to field questions about the added value refineries may bring to the local community.

  5. Black liquor fractionation for biofuels production - a techno-economic assessment.

    Science.gov (United States)

    Mesfun, Sennai; Lundgren, Joakim; Grip, Carl-Erik; Toffolo, Andrea; Nilsson, Rasika Lasanthi Kudahettige; Rova, Ulrika

    2014-08-01

    The hemicelluloses fraction of black liquor is an underutilized resource in many chemical pulp mills. It is possible to extract and separate the lignin and hemicelluloses from the black liquor and use the hemicelluloses for biochemical conversion into biofuels and chemicals. Precipitation of the lignin from the black liquor would consequently decrease the thermal load on the recovery boiler, which is often referred to as a bottleneck for increased pulp production. The objective of this work is to techno-economically evaluate the production of sodium-free lignin as a solid fuel and butanol to be used as fossil gasoline replacement by fractionating black liquor. The hydrolysis and fermentation processes are modeled in Aspen Plus to analyze energy and material balances as well as to evaluate the plant economics. A mathematical model of an existing pulp and paper mill is used to analyze the effects on the energy performance of the mill subprocesses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. The current Russian model of social development, and economic growth

    Directory of Open Access Journals (Sweden)

    V V Paramonov

    2016-12-01

    Full Text Available Although the Article 7 of the Constitution of Russia adopted in 1993 defines the country as a social state, the contemporary social and economic situation is significantly different from this declaration. The author considers the current situation focusing on the foundations of the welfare state. The indicators of social inequality and stratification that allow to identify the country as a social state prove the widening gap between the rich and poor. In recent years, nothing has been done to achieve the more equitable distribution of income and national wealth, which led to the further growth of social inequality exceeding the global indices. The author believes that the high level of social inequality negatively affects the economic growth. Based on the studies of Russian scientists he concludes that equal distribution of income provides higher rates of economic growth and prosperity of the country. The modified theory of the factors of production explains this interconnection, and adds a few more factors, including such a specific resource as sales market, to three factors introduced by J.B. Say at the beginning of the XIX century. The huge social inequality and, consequently, a significant number of the poor deprive the country of such an important resource. To change the situation, the author proposes to return to the progressive tax scale and introduce the zero rate of income tax for the poorest groups in order to create prerequisites for the growth of consumer demand under the economic crisis.

  7. Integrating global socio-economic influences into a regional land use change model for China

    Science.gov (United States)

    Xu, Xia; Gao, Qiong; Peng, Changhui; Cui, Xuefeng; Liu, Yinghui; Jiang, Li

    2014-03-01

    With rapid economic development and urbanization, land use in China has experienced huge changes in recent years; and this will probably continue in the future. Land use problems in China are urgent and need further study. Rapid land-use change and economic development make China an ideal region for integrated land use change studies, particularly the examination of multiple factors and global-regional interactions in the context of global economic integration. This paper presents an integrated modeling approach to examine the impact of global socio-economic processes on land use changes at a regional scale. We develop an integrated model system by coupling a simple global socio-economic model (GLOBFOOD) and regional spatial allocation model (CLUE). The model system is illustrated with an application to land use in China. For a given climate change, population growth, and various socio-economic situations, a global socio-economic model simulates the impact of global market and economy on land use, and quantifies changes of different land use types. The land use spatial distribution model decides the type of land use most appropriate in each spatial grid by employing a weighted suitability index, derived from expert knowledge about the ecosystem state and site conditions. A series of model simulations will be conducted and analyzed to demonstrate the ability of the integrated model to link global socioeconomic factors with regional land use changes in China. The results allow an exploration of the future dynamics of land use and landscapes in China.

  8. MULTIREGION: a simulation-forecasting model of BEA economic area population and employment. [Bureau of Economic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, R.J.; Westley, G.W.; Herzog, H.W. Jr.; Kerley, C.R.; Bjornstad, D.J.; Vogt, D.P.; Bray, L.G.; Grady, S.T.; Nakosteen, R.A.

    1977-10-01

    This report documents the development of MULTIREGION, a computer model of regional and interregional socio-economic development. The MULTIREGION model interprets the economy of each BEA economic area as a labor market, measures all activity in terms of people as members of the population (labor supply) or as employees (labor demand), and simultaneously simulates or forecasts the demands and supplies of labor in all BEA economic areas at five-year intervals. In general the outputs of MULTIREGION are intended to resemble those of the Water Resource Council's OBERS projections and to be put to similar planning and analysis purposes. This report has been written at two levels to serve the needs of multiple audiences. The body of the report serves as a fairly nontechnical overview of the entire MULTIREGION project; a series of technical appendixes provide detailed descriptions of the background empirical studies of births, deaths, migration, labor force participation, natural resource employment, manufacturing employment location, and local service employment used to construct the model.

  9. Global water resources modeling with an integrated model of the social-economic-environmental system

    Science.gov (United States)

    Davies, Evan G. R.; Simonovic, Slobodan P.

    2011-06-01

    Awareness of increasing water scarcity has driven efforts to model global water resources for improved insight into water resources infrastructure and management strategies. Most water resources models focus explicitly on water systems and represent socio-economic and environmental change as external drivers. In contrast, the system dynamics-based integrated assessment model employed here, ANEMI, incorporates dynamic representations of these systems, so that their broader changes affect and are affected by water resources systems through feedbacks. Sectors in ANEMI therefore include the global climate system, carbon cycle, economy, population, land use and agriculture, and novel versions of the hydrological cycle, global water use and water quality. Since the model focus is on their interconnections through explicit nonlinear feedbacks, simulations with ANEMI provide insight into the nature and structure of connections between water resources and socio-economic and environmental change. Of particular interest to water resources researchers and modelers will be the simulated effects of a new water stress definition that incorporates both water quality and water quantity effects into the measurement of water scarcity. Five simulation runs demonstrate the value of wastewater treatment and reuse programs and the feedback-effects of irrigated agriculture and greater consumption of animal products.

  10. Scenario Analysis With Economic-Energy Systems Models Coupled to Simple Climate Models

    Science.gov (United States)

    Hanson, D. A.; Kotamarthi, V. R.; Foster, I. T.; Franklin, M.; Zhu, E.; Patel, D. M.

    2008-12-01

    Here, we compare two scenarios based on Stanford University's Energy Modeling Forum Study 22 on global cooperative and non-cooperative climate policies. In the former, efficient transition paths are implemented including technology Research and Development effort, energy conservation programs, and price signals for greenhouse gas (GHG) emissions. In the non-cooperative case, some countries try to relax their regulations and be free riders. Total emissions and costs are higher in the non-cooperative scenario. The simulations, including climate impacts, run to the year 2100. We use the Argonne AMIGA-MARS economic-energy systems model, the Texas AM University's Forest and Agricultural Sector Optimization Model (FASOM), and the University of Illinois's Integrated Science Assessment Model (ISAM), with offline coupling between the FASOM and AMIGA-MARS and an online coupling between AMIGA-MARS and ISAM. This set of models captures the interaction of terrestrial systems, land use, crops and forests, climate change, human activity, and energy systems. Our scenario simulations represent dynamic paths over which all the climate, terrestrial, economic, and energy technology equations are solved simultaneously Special attention is paid to biofuels and how they interact with conventional gasoline/diesel fuel markets. Possible low-carbon penetration paths are based on estimated costs for new technologies, including cellulosic biomass, coal-to-liquids, plug-in electric vehicles, solar and nuclear energy. We explicitly explore key uncertainties that affect mitigation and adaptation scenarios.

  11. Formation of Behavioural Finance as the Natural Stage of the Human Model Evolution in Economics

    Directory of Open Access Journals (Sweden)

    Viktor Pavlovich Ivanitsky

    2017-09-01

    Full Text Available The paper presents the background analysis of the formation of human model in economics. in the conditions of the constantly performing development of the economic science until the neoclassic paradigm and its modifications. Among them is behavioural finance, which presents a special interest for modern researchers. The evolution of the model of making economically significant decisions in inter-temporal and essential dimensions is the subject matter of the research. We have shown that the concept of the economic human model itself is the multidimensional one. In parallel with the processes of economical, social and political changes and economic science development, the economic human model was becoming more complex and relevant for each period of time. In this regard, we followed the stages of defining the concept of “subject rationality”. The study determines the significant traits implemented by researchers to create a full and consistent human model. We demonstrate the gradual development of economists’ idea of different types of the motivation of economic agents. Along with the financial factors of motivation, the scientists begin to take into account non-financial ones. This approach can help researchers get more “humanistic” view at the economic human. The modern concept of the economic human with attention to its implicit restrictions is formed through the complication of requirements to the rationality and its components crystallization. In the paper, we characterize contribution of the domestic scientists to the development of new directions of economic theory. The research describes the role of different regional economic scientific schools in the process of the formation of the Russian behavioural finance school

  12. On the Practice of Bayesian Inference in Basic Economic Time Series Models using Gibbs Sampling

    NARCIS (Netherlands)

    M.D. de Pooter (Michiel); R. Segers (René); H.K. van Dijk (Herman)

    2006-01-01

    textabstractSeveral lessons learned from a Bayesian analysis of basic economic time series models by means of the Gibbs sampling algorithm are presented. Models include the Cochrane-Orcutt model for serial correlation, the Koyck distributed lag model, the Unit Root model, the Instrumental Variables

  13. Modeling And Economics Of Extreme Subduction Earthquakes: Two Case Studies

    Science.gov (United States)

    Chavez, M.; Cabrera, E.; Emerson, D.; Perea, N.; Moulinec, C.

    2008-05-01

    The destructive effects of large magnitude, thrust subduction superficial (TSS) earthquakes on Mexico City (MC) and Guadalajara (G) has been shown in the recent centuries. For example, the 7/04/1845 and the 19/09/1985, two TSS earthquakes occurred on the coast of the state of Guerrero and Michoacan, with Ms 7+ and 8.1. The economical losses for the later were of about 7 billion US dollars. Also, the largest Ms 8.2, instrumentally observed TSS earthquake in Mexico, occurred in the Colima-Jalisco region the 3/06/1932, and the 9/10/1995 another similar, Ms 7.4 event occurred in the same region, the later produced economical losses of hundreds of thousands US dollars.The frequency of occurrence of large TSS earthquakes in Mexico is poorly known, but it might vary from decades to centuries [1]. Therefore there is a lack of strong ground motions records for extreme TSS earthquakes in Mexico, which as mentioned above, recently had an important economical impact on MC and potentially could have it in G. In this work we obtained samples of broadband synthetics [2,3] expected in MC and G, associated to extreme (plausible) magnitude Mw 8.5, TSS scenario earthquakes, with epicenters in the so-called Guerrero gap and in the Colima-Jalisco zone, respectively. The economical impacts of the proposed extreme TSS earthquake scenarios for MC and G were considered as follows: For MC by using a risk acceptability criteria, the probabilities of exceedance of the maximum seismic responses of their construction stock under the assumed scenarios, and the estimated economical losses observed for the 19/09/1985 earthquake; and for G, by estimating the expected economical losses, based on the seismic vulnerability assessment of their construction stock under the extreme seismic scenario considered. ----------------------- [1] Nishenko S.P. and Singh SK, BSSA 77, 6, 1987 [2] Cabrera E., Chavez M., Madariaga R., Mai M, Frisenda M., Perea N., AGU, Fall Meeting, 2005 [3] Chavez M., Olsen K

  14. Hydro-economic modelling: A comparison between the energy and water sectors

    Science.gov (United States)

    Tilmant, A.

    2008-12-01

    The last 30 years have witnessed a tremendous effort in the development of a variety of models for planning, designing, and managing water resources engineering projects. The water resources community has widely accepted simulation models, which are designed to predict the response of a system under a particular set of conditions. Optimization extends the predictive concept in order to prescribe a set of decisions for achieving an optimal response. Most of the hydro-economic models reported in the literature are based on an economic optimization subject to constraints describing, amongst other things, the hydrological processes. Despite the proven array of benefits offered by hydro-economic models, their generalized use in the water sector is still limited primarily to the academic arena, and it has not been well integrated into practice. This contrasts significantly with the energy sector where hydro-economic models are commonly used for planning and managing hydrothermal electrical systems. We first briefly present the main approaches to hydro- economic modelling and how they are embedded into decision support and analytical frameworks. Then we review the types of policy and decision-making problems that have been addressed with hydro-economic models in both sectors. Some possible causes for the lack of acceptance of and limited implementation of hydro-economic models in the water sector are further discussed.

  15. An Agent-Based Dynamic Model of Politics, Fertility and Economic Development

    OpenAIRE

    Zining Yang

    2016-01-01

    In the political economy of development, government policy choices at a single point in time can dramatically affect a country's development path by impacting fertility, economic and political decisions across generations. Combining system dynamics and agent-based modeling approaches in a complex adaptive system, a simulation framework of the Politics of Fertility and Economic Development (POFED) is formalized to understand the relationship between politics, economic, and demography change at...

  16. Optimal model of economic diplomacy of Republic of Croatia in the contexst of global intelligence revolution

    Directory of Open Access Journals (Sweden)

    Zdravko Bazdan

    2010-12-01

    Full Text Available The aim of this study is to point to the fact that economic diplomacy is a relatively new practice in international economics, specifically the expansion of the occurrence of Intelligence Revolution. The history in global relations shows that without economic diplomacy there is no optimal economic growth and social development. It is important to note that economic diplomacy should be important for our country and the political elite, as well as for the administration of Croatian economic subjects that want to compete in international market economy. Comparative analysis are particularly highlighted by French experience. Therefore, Croatia should copy the practice of those countries that are successful in economic diplomacy. And in the curricula - especially of our economic faculties - we should introduce the course of Economic Diplomacy. It is important to note, that in order to form our optimal model of economic diplomacy which would be headed by the President of Republic of Croatia formula should be based on: Intelligence Security Agency (SOA, Intelligence Service of the Ministry of Foreign Affairs and European Integration, Intelligence Service of the Croatian Chamber of Commerce and the Intelligence Service of the Ministry of Economy, Labor and Entrepreneurship. Described model would consist of intelligence subsystem with at least twelve components.

  17. Quantitative Analysis of Intra Urban Growth Modeling using socio economic agents by combining cellular automata model with agent based model

    Science.gov (United States)

    Singh, V. K.; Jha, A. K.; Gupta, K.; Srivastav, S. K.

    2017-12-01

    Recent studies indicate that there is a significant improvement in the urban land use dynamics through modeling at finer spatial resolutions. Geo-computational models such as cellular automata and agent based model have given evident proof regarding the quantification of the urban growth pattern with urban boundary. In recent studies, socio- economic factors such as demography, education rate, household density, parcel price of the current year, distance to road, school, hospital, commercial centers and police station are considered to the major factors influencing the Land Use Land Cover (LULC) pattern of the city. These factors have unidirectional approach to land use pattern which makes it difficult to analyze the spatial aspects of model results both quantitatively and qualitatively. In this study, cellular automata model is combined with generic model known as Agent Based Model to evaluate the impact of socio economic factors on land use pattern. For this purpose, Dehradun an Indian city is selected as a case study. Socio economic factors were collected from field survey, Census of India, Directorate of economic census, Uttarakhand, India. A 3X3 simulating window is used to consider the impact on LULC. Cellular automata model results are examined for the identification of hot spot areas within the urban area and agent based model will be using logistic based regression approach where it will identify the correlation between each factor on LULC and classify the available area into low density, medium density, high density residential or commercial area. In the modeling phase, transition rule, neighborhood effect, cell change factors are used to improve the representation of built-up classes. Significant improvement is observed in the built-up classes from 84 % to 89 %. However after incorporating agent based model with cellular automata model the accuracy improved from 89 % to 94 % in 3 classes of urban i.e. low density, medium density and commercial classes

  18. Modelling economic interdependencies of international tourism Demand : the global vector autoregressive approach.

    OpenAIRE

    CAO, Z.

    2016-01-01

    Tourism demand is one of the major areas of tourism economics research. The current research studies the interdependencies of international tourism demand across 24 major countries around the world. To this end, it proposes to develop a tourism demand model using an innovative approach, called the global vector autoregressive (GVAR) model. While existing tourism demand models are successful in measuring the causal effects of economic variables on tourism demand for a single origin-destinat...

  19. Simulation of the gasification of animal wastes in a dual gasifier using Aspen Plus®

    International Nuclear Information System (INIS)

    Fernandez-Lopez, M.; Pedroche, J.; Valverde, J.L.; Sanchez-Silva, L.

    2017-01-01

    Highlights: • The gasification of manure was evaluated using the software Aspen Plus®. • Composition and LHV of the obtained syngas depends on the operating conditions. • CO 2 net emissions for the steam and CO 2 gasification processes were calculated. • Manure steam gasification can be used as feedstock for Fischer-Tropsch. • Manure CO 2 gasification lead to a syngas suitable for energy production. - Abstract: The gasification of an animal waste biomass (manure) in a dual gasifier was studied using the software Aspen Plus®. For this purpose, a model based on a Gibbs free energy reactor was considered. Effects of the gasification temperature, the gasifying/biomass ratio and the use of steam and CO 2 as the gasifying agents on the composition and the low heating value (LHV) of the produced syngas were evaluated. In this sense, the H 2 /CO ratio and the LHV were the parameters calculated to stablish the best operating conditions for the production of either hydrocarbons via Fischer-Tropsch or energy. Furthermore, the CO 2 net emissions generated by the gasification process were also important in the selection of the best operating conditions from an environmental point of view. The obtained results showed that for both gasifying agents the H 2 and CO production was favoured at high temperatures whereas the production of CH 4 and CO 2 was favoured at low ones. On the other hand, the H 2 production was higher when steam was used as the gasifying agent and the formation of CO was enhanced when CO 2 was considered as gasification agent. An increase of the gasifying agent/biomass ratio had a negatively influence on the production of CH 4 , leading to a decrease of the LHV. Therefore, steam as the gasifying agent and high temperatures favoured the obtaining of a syngas suitable for the Fischer-Tropsch process whereas CO 2 and low gasification temperatures enhanced a syngas with a high LHV which could be used for energy production. Finally, the net CO 2

  20. Real-time economic optimization for a fermentation process using Model Predictive Control

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Jørgensen, John Bagterp

    2014-01-01

    and demonstrate its usefulness in economic optimization. The model is formulated as an index-1 differential algebraic equation (DAE), which guarantees conservation of mass and energy in discrete form. The optimization is based on recent advances within Economic Nonlinear Model Predictive Control (E......-NMPC), and also utilizes the index-1 DAE model. The E-NMPC uses the single-shooting method and the adjoint method for computation of the optimization gradients. The process constraints are relaxed to soft-constraints on the outputs. Finally we derive the analytical solution to the economic optimization problem...

  1. Aspen Simulation of Diesel-Biodiesel Blends Combustion

    Directory of Open Access Journals (Sweden)

    Pérez-Sánchez Armando

    2015-01-01

    Full Text Available Biodiesel is a fuel produced by transesterification of vegetable oils or animal fats, which currently is gaining attention as a diesel substitute. It represents an opportunity to reduce CO2, SO2, CO, HC, PAH and PM emissions and contributes to the diversification of fuels in Mexico's energetic matrix. The results of the simulation of the combustion process are presented in this paper with reference to an engine specification KUBOTA D600-B, operated with diesel-biodiesel blends. The physicochemical properties of the compounds and the operating conditions of equipment were developed using the simulator Aspen® and supplementary information. The main aspects of the engine working conditions were considered such as diesel-biodiesel ratio, air/fuel mixture, temperature of the combustion gases and heat load. Diesel physicochemical specifications were taken from reports of PEMEX and SENER. Methyl esters corresponding to the transesterification of fatty acids that comprise castor oil were regarded as representative molecules of biodiesel obtained from chromatographic analysis. The results include CO2, water vapor, combustion efficiency, power and lower calorific value of fuels.

  2. Multi-Attribute Modelling of Economic and Ecological Impacts of Cropping Systems

    NARCIS (Netherlands)

    Bohanec, M.; Dzeroski, S.; Znidarsic, M.; Messéan, A.; Scatasta, S.; Wesseler, J.H.H.

    2004-01-01

    Modelling of economic and ecological impacts of genetically modified crops is a demanding task. We present some preliminary attempts made for the purpose of the ECOGEN project "Soil ecological and economic evaluation of genetically modified crops". One of the goals of the project is to develop a

  3. An economic theory-based explanatory model of agricultural land-use patterns

    NARCIS (Netherlands)

    Diogo, V.; Koomen, E.; Kuhlman, T.

    2015-01-01

    An economic theory-based land-use modelling framework is presented aiming to explain the causal link between economic decisions and resulting spatial patterns of agricultural land use. The framework assumes that farmers pursue utility maximisation in agricultural production systems, while

  4. Foreword to the Special Issue on "Dynamic Models in Economics and Finance"

    Science.gov (United States)

    Gardini, Laura; Kubin, Ingrid; Tramontana, Fabio; Wagener, Florian

    2018-05-01

    International workshops on Dynamic Models in Economics and Finance (MDEF) take place every two years in Urbino (Italy); since the inception of the series in 2000, there have been nine editions. The subject has become a central topic for scholars working on economic dynamics. In 2016 the workshop was held under the auspices of University of Urbino "Carlo Bo" , DESP1

  5. Challenges of implementing economic model predictive control strategy for buildings interacting with smart energy systems

    DEFF Research Database (Denmark)

    Zong, Yi; Böning, Georg Martin; Santos, Rui Mirra

    2016-01-01

    When there is a high penetration of renewables in the energy system, it requires proactive control of large numbers of distributed demand response resources to maintain the system’s reliability and improve its operational economics. This paper presents the Economic Model Predictive Control (EMPC)...... and load shifting can be achieved by applying EMPC with weather forecast and dynamic power price signals...

  6. Multi-basin, Multi-sector Drought Economic Impact Model in Python: Development and Applications

    Science.gov (United States)

    Gutenson, J. L.; Zhu, L.; Ernest, A. N. S.; Oubeidillah, A.; Bearden, B.; Johnson, T. G.

    2015-12-01

    Drought is one of the most economically disastrous natural hazards, one whose impacts are exacerbated by the lack of abrupt onset and offset that define tornados and hurricanes. In the United States, about 30 billion dollars losses is caused by drought in 2012, resulting in widespread economic impacts for societies, industries, agriculture, and recreation. And in California, the drought cost statewide economic losses about 2.2 billion, with a total loss of 17,100 seasonal and part-time jobs. Driven by a variety of factors including climate change, population growth, increased water demands, alteration to land cover, drought occurs widely all over the world. Drought economic consequence assessment tool are greatly needed to allow decision makers and stakeholders to anticipate and manage effectively. In this study, current drought economic impact modeling methods were reviewed. Most of these models only deal with the impact in the agricultural sector with a focus on a single basin; few of these models analyze long term impact. However, drought impacts are rarely restricted to basin boundaries, and cascading economic impacts are likely to be significant. A holistic approach to multi-basin, multi-sector drought economic impact assessment is needed.In this work, we developed a new model for drought economic impact assessment, Drought Economic Impact Model in Python (PyDEM). This model classified all business establishments into thirteen categories based on NAICS, and using a continuous dynamic social accounting matrix approach, coupled with calculation of the indirect consequences for the local and regional economies and the various resilience. In addition, Environmental Policy Integrated Climate model was combined for analyzing drought caused soil erosion together with agriculture production, and then the long term impacts of drought were achieved. A visible output of this model was presented in GIS. In this presentation, Choctawhatchee-Pea-Yellow River Basins, Alabama

  7. Ecological-economic modeling for biodiversity management: potential, pitfalls, and prospects

    NARCIS (Netherlands)

    Wätzold, F.; Drechsler, M.; Armstrong, C.W.; Baumgärtner, S.; Grimm, V.; Huth, A.; Perrings, C.; Possingham, H.P.; Shogren, J.F.; Skonhoft, A.; Verboom-Vasiljev, J.; Wissel, C.

    2006-01-01

    Ecologists and economists both use models to help develop strategies for biodiversity management. The practical use of disciplinary models, however, can be limited because ecological models tend not to address the socioeconomic dimension of biodiversity management, whereas economic models tend to

  8. Fuzzy predictive filtering in nonlinear economic model predictive control for demand response

    DEFF Research Database (Denmark)

    Santos, Rui Mirra; Zong, Yi; Sousa, Joao M. C.

    2016-01-01

    The performance of a model predictive controller (MPC) is highly correlated with the model's accuracy. This paper introduces an economic model predictive control (EMPC) scheme based on a nonlinear model, which uses a branch-and-bound tree search for solving the inherent non-convex optimization...

  9. Economics as a factor in models of behavioral motivation and change.

    Science.gov (United States)

    Montoya, I D; Atkinson, J S; Trevino, R A

    2000-02-01

    This note first presents a summary of four main behavioral models that are used to explain behavioral motivation and change. Three models are based on psychosocial theory. They are: 1) the Theory of Reasoned Action, 2) the Theory of Planned Behavior, and 3) the Theory of Stages-of-Change. The fourth model is based on economic theory and is known as the Rational Addiction Model. Each model is analyzed for its strengths and weaknesses. The note concludes by arguing for the usefulness of integrating the economic and the psychosocial models to study drug use. Specific examples and suggestions are presented.

  10. Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site [Abstract

    Science.gov (United States)

    R. Minocha; S. Long; S. Minocha; P Marquardt; M. Kubiske

    2010-01-01

    The objective of the present study was to evaluate the long-term (10 years) effects of elevated CO2 and O3 on the carbon and nitrogen metabolism of aspen trees. The study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA).

  11. Green and economic fleet replacement modeling : part I.

    Science.gov (United States)

    2011-10-01

    "The purpose of this study was to gain a better understanding of how equipment replacement decisions are supported with data collection and : quantitative models at state DOTs, and to determine if models found in the research literature offer any bet...

  12. Phenology and climate relationships in aspen (Populus tremuloides Michx.) forest and woodland communities of southwestern Colorado

    Science.gov (United States)

    Meier, Gretchen A.; Brown, Jesslyn F.; Evelsizer, Ross J.; Vogelmann, James E.

    2014-01-01

    Trembling aspen (Populus tremuloides Michx.) occurs over wide geographical, latitudinal, elevational, and environmental gradients, making it a favorable candidate for a study of phenology and climate relationships. Aspen forests and woodlands provide numerous ecosystem services, such as high primary productivity and biodiversity, retention and storage of environmental variables (precipitation, temperature, snow–water equivalent) that affect the spring and fall phenology of the aspen woodland communities of southwestern Colorado. We assessed the land surface phenology of aspen woodlands using two phenology indices, start of season time (SOST) and end of season time (EOST), from the U.S. Geological Survey (USGS) database of conterminous U.S. phenological indicators over an 11-year time period (2001–2011). These indicators were developed with 250 m resolution remotely sensed data from the Moderate Resolution Imaging Spectroradiometer processed to highlight vegetation response. We compiled data on SOST, EOST, elevation, precipitation, air temperature, and snow water equivalent (SWE) for selected sites having more than 80% cover by aspen woodland communities. In the 11-year time frame of our study, EOST had significant positive correlation with minimum fall temperature and significant negative correlation with fall precipitation. SOST had a significant positive correlation with spring SWE and spring maximum temperature.

  13. Forest stand structure, productivity, and age mediate climatic effects on aspen decline

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  14. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

    2008-10-01

    Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

  15. Model integration and the economics of nuclear power

    International Nuclear Information System (INIS)

    Lundgren, S.

    1985-01-01

    The author proposes and applies a specific approach to model integration, i.e. the merger of two or several independently developed models. The approach is intended for integrations of activity analysis sector models and applied general equilibrium models. Model integration makes it possible to extend the range of applicability of applied general equilibrium models by exploiting the information contained in sector models. It also makes it possible to evaluate the validity of the partial equilibrium analyses in which sector models often are employed. The proposed approach is used to integrate a sector model of electricity and heat production with a general equilibrium model of the Swedish economy. Both models have been constructed within the research programme. The author uses the integrated model to look at two issues concerning the role of nuclear power on the Swedish electricity market: What are the likely consequences of a nuclear power discontinuation and how does the nuclear power investment programme of the 1970's and the early 1980's compare with a socially efficient one. (Author)

  16. Analysis of Economic Burden of Seasonal Influenza: An Actuarial Based Conceptual Model

    Directory of Open Access Journals (Sweden)

    S. S. N. Perera

    2017-01-01

    Full Text Available Analysing the economic burden of the seasonal influenza is highly essential due to the large number of outbreaks in recent years. Mathematical and actuarial models can be considered as management tools to understand the dynamical behavior, predict the risk, and compute it. This study is an attempt to develop conceptual model to investigate the economic burden due to seasonal influenza. The compartment SIS (susceptible-infected-susceptible model is used to capture the dynamical behavior of influenza. Considering the current investment and future medical care expenditure as premium payment and benefit (claim, respectively, the insurance and actuarial based conceptual model is proposed to model the present economic burden due to the spread of influenza. Simulation is carried out to demonstrate the variation of the present economic burden with respect to model parameters. The sensitivity of the present economic burden is studied with respect to the risk of disease spread. The basic reproduction is used to identify the risk of disease spread. Impact of the seasonality is studied by introducing the seasonally varying infection rate. The proposed model provides theoretical background to investigate the economic burden of seasonal influenza.

  17. Towards low carbon business park energy systems: Classification of techno-economic energy models

    International Nuclear Information System (INIS)

    Timmerman, Jonas; Vandevelde, Lieven; Van Eetvelde, Greet

    2014-01-01

    To mitigate climate destabilisation, human-induced greenhouse gas emissions urgently need to be curbed. A major share of these emissions originates from the industry and energy sectors. Hence, a low carbon shift in industrial and business park energy systems is called for. Low carbon business parks minimise energy-related carbon dioxide emissions by maximal exploitation of local renewable energy production, enhanced energy efficiency, and inter-firm heat exchange, combined in a collective energy system. The holistic approach of techno-economic energy models facilitates the design of such systems, while yielding an optimal trade-off between energetic, economic and environmental performances. However, no models custom-tailored for industrial park energy systems are detected in literature. In this paper, existing energy model classifications are scanned for adequate model characteristics and accordingly, a confined number of models are selected and described. Subsequently, a practical typology is proposed, existing of energy system evolution, optimisation, simulation, accounting and integration models, and key model features are compared. Finally, important features for a business park energy model are identified. - Highlights: • A holistic perspective on (low carbon) business park energy systems is introduced. • A new categorisation of techno-economic energy models is proposed. • Model characteristics are described per model category. • Essential model features for business park energy system modelling are identified. • A strategy towards a techno-economic energy model for business parks is proposed

  18. Moderate-scale mapping methods of aspen stand types: a case study for Cedar Mountain in southern Utah

    Science.gov (United States)

    Chad M. Oukrop; David M. Evans; Dale L. Bartos; R. Douglas Ramsey; Ronald J. Ryel

    2011-01-01

    Quaking aspen (Populus tremuloides Michx.) are the most widely distributed tree species across North America, but its dominance is declining in many areas of the western United States, with certain areas experiencing rapid mortality events over the past decade. The loss of aspen from western landscapes will continue to profoundly impact biological, commercial, and...

  19. Bioenergy harvest impacts to biodiversity and resilience vary across aspen-dominated forest ecosystems in the Lake States region, USA

    Science.gov (United States)

    Miranda T. Curzon; Anthony W. D' Amato; Brian J. Palik; Kris Verheyen

    2016-01-01

    Questions: Does the increase in disturbance associated with removing harvest residues negatively impact biodiversity and resilience in aspen-dominated forest ecosystems? How do responses of functional diversity measures relate to community recovery and standing biomass? Location: Aspen (Populus tremuloides, Michx.) mixedwood forests in Minnesota...

  20. Will photosynthetic capacity of aspen trees acclimate after long term exposure to elevated CO2 and O3?

    Science.gov (United States)

    Joseph N.T. Darbah; Mark E. Kubiske; Neil Nelson; Katre Kets; Johanna Riikonen; Anu Sober; Lisa Rouse; David F. Karnosky

    2010-01-01

    Photosynthetic acclimation under elevated carbon dioxide (CO2) and/or ozone (O3) has been the topic of discussion in many papers recently. We examined whether or not aspen plants grown under elevated CO2 and/or O3 will acclimate after 11 years of exposure at the Aspen Face site...

  1. Persistence of aspen regeneration near the National Elk Refuge and Gros Ventre Valley Elk Feedgrounds of Wyoming

    Science.gov (United States)

    David T. Barnett; Thomas J. Stohlgren

    2001-01-01

    We investigated aspen (Populus tremuloides) regeneration in the Gros Ventre River Valley, the National Elk Refuge, and a small part of Grand Teton National Park, Wyoming, to see if elk (Cervus elaphus) browsing was as damaging as previously thought. We conducted a landscape-scale survey to assess aspen regeneration across gradients of wintering elk concentrations using...

  2. Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA

    Science.gov (United States)

    Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

    2003-01-01

    We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

  3. Adaptive institutions? Peasant institutions and natural models facing climatic and economic changes in the Colombian Andes

    NARCIS (Netherlands)

    Feola, Giuseppe

    2017-01-01

    In the Colombian Andes, peasants have co-evolved with their environment for centuries, but it is uncertain whether traditional informal institutions and natural models are adapting to current and possibly unprecedented economic and climatic disturbances. This study investigated institutional

  4. New Perspectives on Economic Modeling for Digital Curation

    DEFF Research Database (Denmark)

    Grindley, Neil; Kejser, Ulla Bøgvad; L'Hours, Hervé

    2014-01-01

    Society is increasingly dependent on the availability of digital information assets however the resources that are available for managing the assets over time (curating) are limited. As such, it is increasingly vital that organizations are able to judge the effectiveness of their investments...... into curation activities. For those responsible for digital curation, it is an ongoing challenge to ensure that the assets remain valuable in a sustainable manner. Digital curation and preservation practices are still evolving and they are not well aligned across different organizations and different sectors...... with a demand for curation of digital assets and suppliers of curation services and solutions. Further, the framework reflects the context in which managers operate and how this context influences their decision-making. This should enable managers to think through different scenarios around the economics...

  5. Simulating Quantile Models with Applications to Economics and Management

    Science.gov (United States)

    Machado, José A. F.

    2010-05-01

    The massive increase in the speed of computers over the past forty years changed the way that social scientists, applied economists and statisticians approach their trades and also the very nature of the problems that they could feasibly tackle. The new methods that use intensively computer power go by the names of "computer-intensive" or "simulation". My lecture will start with bird's eye view of the uses of simulation in Economics and Statistics. Then I will turn out to my own research on uses of computer- intensive methods. From a methodological point of view the question I address is how to infer marginal distributions having estimated a conditional quantile process, (Counterfactual Decomposition of Changes in Wage Distributions using Quantile Regression," Journal of Applied Econometrics 20, 2005). Illustrations will be provided of the use of the method to perform counterfactual analysis in several different areas of knowledge.

  6. Danish wind turbines: Technical-economic feasibility of commercial models

    International Nuclear Information System (INIS)

    Falchetta, M.

    1992-01-01

    This feasibility study examines the principal technical and economic (investment-manufacturing-installation-operation unit costs, supply and demand) characteristics of wind turbines being commercialized in Denmark. The general configuration of the 150 to 450 kW range machines currently being manufactured can be described as that of a three bladed fibreglass rotor, of from 24 to 35 meters in diameter, and mounted on a tower of from 29 to 41 meters in height. The electrical system consists of one asynchronous generator or a two generator system with a power ratio of 1 to 5 between the two generators. The cost analysis reveals that the Danish wind turbines are competitively priced, with per kWh costs varying from $0. 0675 to $0. 040 for operating wind speeds ranging from 5 to 7 m/sec, and that their overall design and performance characteristics make them suitable for Italian site conditions

  7. MODEL PENENTUAN HARGA SAHAM: PENGUJIAN CAPITAL ASSET PRICING MODEL MELALUI PENGUJIAN ECONOMIC VALUE ADDED

    Directory of Open Access Journals (Sweden)

    Suripto Suripto

    2017-03-01

    Full Text Available This research tested the influence of characteristics of the firms and of EVA (Eco-nomic Value Added to stock of returns. This Research sample was company Self-100 ValueCreator of year 2001 until 2006. Result of research indicated that company size measure,profitability, capital structure (characteristics of the firms and EVA by stimulant had aneffect on significant to stock of returns, but by partial only characteristics company. Condi-tion of company fundamentals had an effect on significance to stock of returns. This indica-tion that investor still considered factors of fundamentals was having investment. EVA didnot have an effect on significant to stock of returns. This finding indicated that Model deter-mination of stock of returns (CAPM Irrelevant determined the level of EVA and also indicatedthat CAPM (Capital Assets Pricing Model was not relevant in determining stock of returns inIndonesian Stock Exchange.

  8. Why is Africa so poor? A structural model of economic development and income inequality.

    OpenAIRE

    David Fielding

    2001-01-01

    The paper extends existing work on inequality and economic development by estimating a cross-country structural model that identifies bi-directional relationships between income inequality and other indicators of social and economic development. Overall, lower inequality is associated with improvements in other development indicators, but this is the result of several complex interactions. The most striking feature of the structural model is the insight it provides into the reasons behind the...

  9. Ecosystem-based fishery management: A critical review of concepts and ecological economic models

    OpenAIRE

    Nguyen, Thanh Viet

    2009-01-01

    An ecosystem approach means different things to different people. As a result the concept of ecosystem-based fishery management is evolving and it has no universal definition or consistent application. As regards ecosystem modeling, most economic models of fishery ignore the linkages to lower trophic levels. In particular, environmental data and other bottom-up information is widely disregarded. The objective of this paper is to provide a critical review of concepts and ecological economic mo...

  10. Jobs and Economic Development Impact (JEDI) Model: Offshore Wind User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, E.; Goldberg, M.; Keyser, D.

    2013-06-01

    The Offshore Wind Jobs and Economic Development Impact (JEDI) model, developed by NREL and MRG & Associates, is a spreadsheet based input-output tool. JEDI is meant to be a user friendly and transparent tool to estimate potential economic impacts supported by the development and operation of offshore wind projects. This guide describes how to use the model as well as technical information such as methodology, limitations, and data sources.

  11. Links between fluid mechanics and quantum mechanics: a model for information in economics?

    Science.gov (United States)

    Haven, Emmanuel

    2016-05-28

    This paper tallies the links between fluid mechanics and quantum mechanics, and attempts to show whether those links can aid in beginning to build a formal template which is usable in economics models where time is (a)symmetric and memory is absent or present. An objective of this paper is to contemplate whether those formalisms can allow us to model information in economics in a novel way. © 2016 The Author(s).

  12. Energy demand analytics using coupled technological and economic models

    Science.gov (United States)

    Impacts of a range of policy scenarios on end-use energy demand are examined using a coupling of MARKAL, an energy system model with extensive supply and end-use technological detail, with Inforum LIFT, a large-scale model of the us. economy with inter-industry, government, and c...

  13. A Dynamic Economic Model with Discrete Time and Consumer Sentiment

    Directory of Open Access Journals (Sweden)

    L. I. Dobrescu

    2009-01-01

    is replaced by a (quasi periodic motion. We associate the difference stochastic equation to the model by randomizing the control parameter d and by adding one stochastic control. Numerical simulations are made for the deterministic and stochastic models, for different values of the control parameter d.

  14. Modelling the economic tradeoffs between allocating water for crop ...

    African Journals Online (AJOL)

    2009-06-05

    Jun 5, 2009 ... typically evaluated with an optimisation model. Critical to the analysis is the modelling of the non-linear relationship between the increasing leaching requirement, resulting from soil water salinity, and final crop yield as affected by soil water salinity. Within a South African context, Armour and Viljoen (2002;.

  15. JEDI: Jobs and Economic Development Impact Model; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL’s researchers to model wind energy jobs and impacts, JEDI has been expanded to also estimate the economic impacts of biofuels, coal, conventional hydro, concentrating solar power, geothermal, marine and hydrokinetic power, natural gas, photovoltaics, and transmission lines. This fact sheet focuses on JEDI for wind energy projects.

  16. A Mathematical Model of Economic Population Dynamics in a Country That Has Optimal Zakat Management

    Science.gov (United States)

    Subhan, M.

    2018-04-01

    Zakat is the main tools against two issues in Islamic economy: economic justice and helping the poor. However, no government of Islamic countries can solve the economic disparity today. A mathematical model could give some understanding about this phenomenon. The goal of this research is to obtain a mathematical model that can describe the dynamic of economic group population. The research is theoretical based on relevance references. From the analytical and numerical simulation, we conclude that well-manage zakat and full comitment of the wealthy can achieve wealth equilibrium that represents minimum poverty.

  17. Stand Dynamics, Humus Type and Water Balance Explain Aspen Long Term Productivity across Canada

    Directory of Open Access Journals (Sweden)

    Kenneth A. Anyomi

    2015-02-01

    Full Text Available This study examined the relative importance of soil, stand development and climate hypotheses in driving productivity for a species that is widely distributed in North America. Inventory plots, 3548 of such, either dominated by aspen or made up of species mixture of which aspen occurs in dominant canopy position were sampled along a longitudinal gradient from Quebec to British Columbia. Site index (SI, was used as a measure of productivity, and soil, climate and stand attributes were correlated with site index in order to determine their effects on productivity. Results show a decline in productivity with high moisture deficit. Soil humus correlates significantly with SI but does not sufficiently capture differential rates of litter deposition and decomposition effects over the long-term. Consequently, aspen composition, stand ageing, and stand structural changes dominate variability in productivity. Within the context where deciduous cover has being increasing, there are implications for forest productivity.

  18. Fibrillation of Aspen by Alkaline Cold Pre-treatment and Vibration Milling

    Directory of Open Access Journals (Sweden)

    Kärt KÄRNER

    2016-09-01

    Full Text Available In this article an attempt to fibrillate aspen bleached chemi-thermo mechanical pulp (BCTMP fibre in an environmentally friendly way is reported. The effects of various NaOH, KOH, urea and ethanol aqueous solutions at lowered temperature were tested for pre-treatment. The pre-treatment was followed by vibration milling aiming to peel off outer cell wall layers and to fibrillate S2 layer of the aspen wood fibre. The effects of the treatments were evaluated by scanning electron microscopy (SEM. The results show that it is possible to fibrillate BCTMP aspen fibres by using alkaline aqueous solutions at low temperatures followed by a mechanical treatment. A strong dependence on fibrillation of cellulose on temperature, time and alkali concentration was established.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7412

  19. Total Economic Value of Applied Used Green Line Street Model For Tamarindus Indica in Rembang District

    Directory of Open Access Journals (Sweden)

    Rangga Fajar Abdillah

    2018-01-01

    Full Text Available One of the green line street functions is to providing land of carbon sink crops. Javanese tamarind (Tamarindus indica is a type of productive crop that has a carbon absorbent function. The type of Javanese tamarind crops production is wood products and tamarind fruit harvest products. The purpose of this study to determine the total economic value (NET a calculation of the model of the applied use of green line street for Javanese tamarind plants .The economic value that can be calculated from the modeling are Direct Value and Indirect Value. Direct benefit value consist of value of wood and value of crop. While indirect benefits value consist of value of carbon stock and biodiversity value. This research was conducted in May 2017 in Rembang District, Rembang Regency, Central Java. The methods used are allometric modeling method and economic valuation method. Allometric modeling method is used to determine the potential of carbon and wood reserves along the green line street. While the economic valuation method is used to calculate total economic value of the application of this modeling result. Applying of this model has result in total economic value Rp 1,942,788,721 per year. It can be concluded that the green liner street has great potential utilization and should be optimally utilized.

  20. Total Economic Value of Applied Used Green Line Street Model For Tamarindus Indica in Rembang District

    Science.gov (United States)

    Fajar, Abdillah Rangga; Nur, Bambang Azis

    2018-02-01

    One of the green line street functions is to providing land of carbon sink crops. Javanese tamarind (Tamarindus indica) is a type of productive crop that has a carbon absorbent function. The type of Javanese tamarind crops production is wood products and tamarind fruit harvest products. The purpose of this study to determine the total economic value (NET) a calculation of the model of the applied use of green line street for Javanese tamarind plants .The economic value that can be calculated from the modeling are Direct Value and Indirect Value. Direct benefit value consist of value of wood and value of crop. While indirect benefits value consist of value of carbon stock and biodiversity value. This research was conducted in May 2017 in Rembang District, Rembang Regency, Central Java. The methods used are allometric modeling method and economic valuation method. Allometric modeling method is used to determine the potential of carbon and wood reserves along the green line street. While the economic valuation method is used to calculate total economic value of the application of this modeling result. Applying of this model has result in total economic value Rp 1,942,788,721 per year. It can be concluded that the green liner street has great potential utilization and should be optimally utilized.

  1. ADVISHE: A new tool to report validation of health-economic decision models

    NARCIS (Netherlands)

    Vemer, P.; Corro Ramos, I.; Van Voorn, G.; Al, M.J.; Feenstra, T.L.

    2014-01-01

    Background: Modelers and reimbursement decision makers could both profit from a more systematic reporting of the efforts to validate health-economic (HE) models. Objectives: Development of a tool to systematically report validation efforts of HE decision models and their outcomes. Methods: A gross

  2. Empirical agent-based land market: Integrating adaptive economic behavior in urban land-use models

    NARCIS (Netherlands)

    Filatova, Tatiana

    2015-01-01

    This paper introduces an economic agent-based model of an urban housing market. The RHEA (Risks and Hedonics in Empirical Agent-based land market) model captures natural hazard risks and environmental amenities through hedonic analysis, facilitating empirical agent-based land market modeling. RHEA

  3. Defensive effects of extrafloral nectaries in quaking aspen differ with scale.

    Science.gov (United States)

    Mortensen, Brent; Wagner, Diane; Doak, Patricia

    2011-04-01

    The effects of plant defenses on herbivory can differ among spatial scales. This may be particularly common with indirect defenses, such as extrafloral nectaries (EFNs), that attract predatory arthropods and are dependent on predator distribution, abundance, and behavior. We tested the defensive effects of EFNs in quaking aspen (Populus tremuloides Michx.) against damage by a specialist herbivore, the aspen leaf miner (Phyllocnistis populiella Cham.), at the scale of individual leaves and entire ramets (i.e., stems). Experiments excluding crawling arthropods revealed that the effects of aspen EFNs differed at the leaf and ramet scales. Crawling predators caused similar reductions in the percent leaf area mined on individual leaves with and without EFNs. However, the extent to which crawling predators increased leaf miner mortality and, consequently, reduced mining damage increased with EFN expression at the ramet scale. Thus, aspen EFNs provided a diffuse defense, reducing damage to leaves across a ramet regardless of leaf-scale EFN expression. We detected lower leaf miner damage and survival unassociated with crawling predators on EFN-bearing leaves, suggesting that direct defenses (e.g., chemical defenses) were stronger on leaves with than without EFNs. Greater direct defenses on EFN-bearing leaves may reduce the probability of losing these leaves and thus weakening ramet-scale EFN defense. Aspen growth was not related to EFN expression or the presence of crawling predators over the course of a single season. Different effects of aspen EFNs at the leaf and ramet scales suggest that future studies may benefit from examining indirect defenses simultaneously at multiple scales.

  4. Nuclear energy, renewable energy, and economic growth in developed and developing countries : A modelling analysis from simultaneous-equation models

    OpenAIRE

    Anis Omri; Anissa Chaibi

    2014-01-01

    This paper investigates the causal relationship among two types of energy consumption (nuclear energy and renewable energy) and economic growth using dynamic simultaneous-equation panel data models for 17 developed and developing countries. Our results in

  5. Sustainable innovation, business models and economic performance: an overview

    NARCIS (Netherlands)

    Montalvo Corral, C.

    2013-01-01

    Sustainable development requires radical and systemic innovations. Such innovations can be more effectively created and studied when building on the concept of business models. This concept provides firms with a holistic framework to envision and implement sustainable innovations. For researchers,

  6. WASTES: a waste management logistics/economics model

    International Nuclear Information System (INIS)

    McNair, G.W.; Shay, M.R.; Fletcher, J.F.; Cashwell, J.W.

    1985-02-01

    The WASTES model simulates a user defined system for nuclear waste transportation and storage at both temporary and long-term storage facilities. The model is written in FORTRAN 77 as an extension to the SLAM commercial simulation package (Pritsker and Pegden 1979). SLAM (Simulation Language for Alternative Modeling) is utilized in a discrete event mode to model the passage of spent fuel through the system. The system is initiated with individual reactor discharges of spent fuel as described in the reactor discharge data file or as supplied by the user. The reactor discharge file contains deterministic information on the date (year/month) and quantity of spent fuel discharges. From this point, the model is controlled by a combination of source originated and destination originated transfers. Source driven transfers occur when a reactor pool violates the full core reserve (FCR) storage margin or when the reactor is decommissioned. At these times, the source reactor checks destination facilities to see if they can accept material. A dry storage facility is assumed to exist for each reactor and is allowed to grow as necessary to contain spent fuel which cannot be shipped to any other facility. In this way the FCR margin is always maintained. Destination driven transfers occur when the annual capacity of a facility will not be met by full core reserve or decommissioning shipments. An attempt is made at the end of each calendar year to schedule enough shipments of spent fuel from facilities with non-critical storage capacity to fill the annual capacity of each destination facility. Allowable facility types are reprocessing plants, federal interim storage (FIS), monitored retrievable storage (MRS), and repositories. The number, capacities, location and priority for receipt of spent fuel is user specified. This report describes in detail the waste generating model, the waste facilities model, the transportation model and the basic transportation scheme

  7. Integrated modelling of economic-energy-environment scenarios - The impact of China and India's economic growth on energy use and CO2 emissions

    International Nuclear Information System (INIS)

    Roques, F.; Sassi, O.; Guivarch, C.; Waisman, H.; Crassous, R.; Hourcade, J.Ch.

    2009-03-01

    A hybrid framework coupling the bottom-up energy sector WEM model with the top-down general equilibrium model IMACLIM-R is implemented to capture the macro-economic feedbacks of Chinese and Indian economic growth on energy and emissions scenarios. The iterative coupling procedure captures the detailed representation of energy use and supply while ensuring the micro-economic and macro-economic consistency of the different scenarios studied. The dual representation of the hybrid model facilitates the incorporation of energy sector expertise in internally consistent scenarios. The paper describes how the hybrid model was used to assess the effect of uncertainty on economic growth in China and India in the energy and emissions scenarios of the International Energy Agency. (authors)

  8. Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Jasiunas, Lukas; Casamassima, Luca

    2015-01-01

    Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co-processing ......Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co...

  9. Landscape-Scale Dynamics of Aspen in Rocky Mountain National Park, Colorado

    OpenAIRE

    Kaye, Margot W; Suzuki, Kuni; Binkley, Dan; Stohlgren, Thomas J

    2001-01-01

    Past studies of quaking aspen in Rocky Mountain National Park suggested that the aspen population is declining due to intensive browsing by elk (Cervus elaphus). These studies were conducted in the elk winter range, an area of intensive elk impact. The elk summer range experiences less intense grazing pressure. We tested the hypothesis that impacts of elk would be greater in the elk winter range than the summer range with landscape-scale data from the Park. The detrimental effects of elk on a...

  10. User Guide for the International Jobs and Economic Development Impacts Model

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States); Uriarte, Caroline [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cox, Sadie [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    The International Jobs and Economic Development Impacts (I-JEDI) model is a freely available economic model that estimates gross economic impacts from wind, solar, and geothermal energy projects for several different countries. Building on the original JEDI model, which was developed for the United States, I-JEDI was developed under the USAID Enhancing Capacity for Low Emission Development Strategies (EC-LEDS) program to support countries in assessing economic impacts of LEDS actions in the energy sector. I-JEDI estimates economic impacts by characterizing the construction and operation of energy projects in terms of expenditures and the portion of these expenditures made within the country of analysis. These data are then used in a country-specific input-output (I-O) model to estimate employment, earnings, gross domestic product (GDP), and gross output impacts. Total economic impacts are presented as well as impacts by industry. This user guide presents general information about how to use I-JEDI and interpret results as well as detailed information about methodology and model limitations.

  11. Using ecosystem services to represent the environment in hydro-economic models

    Science.gov (United States)

    Momblanch, Andrea; Connor, Jeffery D.; Crossman, Neville D.; Paredes-Arquiola, Javier; Andreu, Joaquín

    2016-07-01

    Demand for water is expected to grow in line with global human population growth, but opportunities to augment supply are limited in many places due to resource limits and expected impacts of climate change. Hydro-economic models are often used to evaluate water resources management options, commonly with a goal of understanding how to maximise water use value and reduce conflicts among competing uses. The environment is now an important factor in decision making, which has resulted in its inclusion in hydro-economic models. We reviewed 95 studies applying hydro-economic models, and documented how the environment is represented in them and the methods they use to value environmental costs and benefits. We also sought out key gaps and inconsistencies in the treatment of the environment in hydro-economic models. We found that representation of environmental values of water is patchy in most applications, and there should be systematic consideration of the scope of environmental values to include and how they should be valued. We argue that the ecosystem services framework offers a systematic approach to identify the full range of environmental costs and benefits. The main challenges to more holistic representation of the environment in hydro-economic models are the current limits to understanding of ecological functions which relate physical, ecological and economic values and critical environmental thresholds; and the treatment of uncertainty.

  12. System dynamics modelling and simulating the effects of intellectual capital on economic growth

    Directory of Open Access Journals (Sweden)

    Ivona Milić Beran

    2015-10-01

    Full Text Available System dynamics modelling is one of the best scientific methods for modelling complex, nonlinear natural, economic and technical system dynamics as it enables both monitoring and assessment of the effects of intellectual capital on economic growth. Intellectual capital is defined as “the ability to transform knowledge and intangible assets into resources to create wealth for a company and a country.” Transformation of knowledge is crucial. Knowledge increases a country’s wealth only if its importance is recognized and applied differently from existing work practices. The aim of this paper is to show the efficiency of modelling system dynamics and simulating the effects of intellectual capital on economic growth. A computer simulation provided a mathematical model, providing practical insight into the dynamic behavior of the observed system, i.e. the analysis of economic growth and observation of mutual correlation between individual parameters. The results of the simulation are presented in graphical form. The dynamic model of the effects of intellectual capital on Croatia’s economic growth has been verified by comparing simulation results with existing data on economic growth.

  13. Langevin processes, agent models and socio-economic systems

    Science.gov (United States)

    Richmond, Peter; Sabatelli, Lorenzo

    2004-05-01

    We review some approaches to the understanding of fluctuations of financial asset prices. Our approach builds on the development of a simple Langevin equation that characterises stochastic processes. This provides a unifying approach that allows first a straightforward description of the early approaches of Bachelier. We generalize the approach to stochastic equations that model interacting agents. The agent models recently advocated by Marsilli and Solomon are motivated. Using a simple change of variable, we show that the peer pressure model of Marsilli and the wealth dynamics model of Solomon are essentially equivalent. The methods are further shown to be consistent with a global free energy functional that invokes an entropy term based on the Boltzmann formula. There follows a brief digression on the Heston model that extends the simple model to one that, in the language of physics, exhibits a temperature this is subject to stochastic fluctuations. Mathematically the model corresponds to a Feller process. Dragulescu and Yakovenko have shown how the model yields some of the stylised features of asset prices. A more recent approach by Michael and Johnson maximised a Tsallis entropy function subject to simple constraints. They obtain a distribution function for financial returns that exhibits power law tails and which can describe the distribution of returns not only over low but also high frequencies (minute by minute) data for the Dow Jones index. We show how this approach can be developed from an agent model, where the simple Langevin process is now conditioned by local rather than global noise. Such local noise may of course be the origin of speculative frenzy or herding in the market place. The approach yields a BBGKY type hierarchy of equations for the system correlation functions. Of especial interest is that the results can be obtained from a new free energy functional similar to that mentioned above except that a Tsallis like entropy term replaces the

  14. Introducing formalism in economics: The growth model of John von Neumann

    Directory of Open Access Journals (Sweden)

    Gloria-Palermo Sandye

    2010-01-01

    Full Text Available The objective is to interpret John von Neumann's growth model as a decisive step of the forthcoming formalist revolution of the 1950s in economics. This model gave rise to an impressive variety of comments about its classical or neoclassical underpinnings. We go beyond this traditional criterion and interpret rather this model as the manifestation of von Neumann's involvement in the formalist programme of mathematician David Hilbert. We discuss the impact of Kurt Gödel's discoveries on this programme. We show that the growth model reflects the pragmatic turn of the formalist programme after Gödel and proposes the extension of modern axiomatisation to economics.

  15. Integrating Economic Models with Biophysical Models in the Willamette Water 2100 Project

    Science.gov (United States)

    Jaeger, W. K.; Plantinga, A.

    2013-12-01

    This paper highlights the human system modeling components for Willamette Water 2100, a comprehensive, highly integrated study of hydrological, ecological, and human factors affecting water scarcity in the Willamette River Basin (WRB). The project is developing a spatiotemporal simulation model to predict future trajectories of water scarcity, and to evaluate mitigation policies. Economic models of land use and water use are the main human system models in WW2100. Water scarcity depends on both supply and demand for water, and varies greatly across time and space (Jaeger et al., 2013). Thus, the locations of human water use can have enormous influence on where and when water is used, and hence where water scarcity may arise. Modeling the locations of human uses of water (e.g., urban versus agricultural) as well as human values and choices, are the principal quantitative ways that social science can contribute to research of this kind. Our models are empirically-based models of human resource allocation. Each model reflects private behavior (choices by households, farms, firms), institutions (property rights, laws, markets, regulations), public infrastructure (dams, canals, highways), and also 'external drivers' that influence the local economy (migration, population growth, national markets and policies). This paper describes the main model components, emphasizing similarities between human and biophysical components of the overall project, and the model's linkages and feedbacks relevant to our predictions of changes in water scarcity between now and 2100. Results presented include new insights from individual model components as well as available results from the integrated system model. Issues include water scarcity and water quality (temperature) for out-of-stream and instream uses, the impact of urban expansion on water use and potential flood damage. Changes in timing and variability of spring discharge with climate change, as well as changes in human uses of

  16. Integrated economic model of waste management: Case study for South Moravia region

    Directory of Open Access Journals (Sweden)

    Jiří Hřebíček

    2013-01-01

    Full Text Available The paper introduces and discusses the developed integrated economic model of municipal waste management of the Czech Republic, which was developed by authors as a balanced network model for a set of sources (mostly municipalities of municipal solid waste connected with a set of chosen waste treatment facilities processing their waste. Model is implemented as a combination of several economic submodels including environmental and economic point of view. It enables to formulate the optimisation problem in a concise way and the resulting model is easily scalable. Model involves submodels of waste prevention, collection and transport optimization, submodels of waste energy utilization (incineration and biogas plants and material recycling (composting and submodel of landfilling. Its size (number of sources and facilities depends only upon available data. Its application is used in the case study of the South Moravia region with verification of using time series waste data. The results enable to improve decision making in waste management sector.

  17. Transmission Line Jobs and Economic Development Impact (JEDI) Model User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, M.; Keyser, D.

    2013-10-01

    The Jobs and Economic Development Impact (JEDI) models, developed through the National Renewable Energy Laboratory (NREL), are freely available, user-friendly tools that estimate the potential economic impacts of constructing and operating power generation projects for a range of conventional and renewable energy technologies. The Transmission Line JEDI model can be used to field questions about the economic impacts of transmission lines in a given state, region, or local community. This Transmission Line JEDI User Reference Guide was developed to provide basic instruction on operating the model and understanding the results. This guide also provides information on the model's underlying methodology, as well as the parameters and references used to develop the cost data contained in the model.

  18. Forecasting performance of three automated modelling techniques during the economic crisis 2007-2009

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl; Teräsvirta, Timo

    In this work we consider forecasting macroeconomic variables during an economic crisis. The focus is on a speci…c class of models, the so-called single hidden-layer feedforward autoregressive neural network models. What makes these models interesting in the present context is that they form a class...... during the economic crisis 2007–2009. Forecast accuracy is measured by the root mean square forecast error. Hypothesis testing is also used to compare the performance of the different techniques with each other....... of universal approximators and may be expected to work well during exceptional periods such as major economic crises. These models are often difficult to estimate, and we follow the idea of White (2006) to transform the speci…cation and nonlinear estimation problem into a linear model selection and estimation...

  19. Mathematical-statistical models and qualitative theories for economic and social sciences

    CERN Document Server

    Maturo, Fabrizio; Kacprzyk, Janusz

    2017-01-01

    This book presents a broad spectrum of problems related to statistics, mathematics, teaching, social science, and economics as well as a range of tools and techniques that can be used to solve these problems. It is the result of a scientific collaboration between experts in the field of economic and social systems from the University of Defence in Brno (Czech Republic), G. d’Annunzio University of Chieti-Pescara (Italy), Pablo de Olavid eUniversity of Sevilla (Spain), and Ovidius University in Constanţa, (Romania). The studies included were selected using a peer-review process and reflect heterogeneity and complexity of economic and social phenomena. They and present interesting empirical research from around the globe and from several research fields, such as statistics, decision making, mathematics, complexity, psychology, sociology and economics. The volume is divided into two parts. The first part, “Recent trends in mathematical and statistical models for economic and social sciences”, collects pap...

  20. A Discrete Heterogeneous-Group Economic Growth Model with Endogenous Leisure Time

    Directory of Open Access Journals (Sweden)

    Wei-Bin Zhang

    2009-01-01

    Full Text Available This paper proposes a one-sector multigroup growth model with endogenous labor supply in discrete time. Proposing an alternative approach to behavior of households, we examine the dynamics of wealth and income distribution in a competitive economy with capital accumulation as the main engine of economic growth. We show how human capital levels, preferences, and labor force of heterogeneous households determine the national economic growth, wealth, and income distribution and time allocation of the groups. By simulation we demonstrate, for instance, that in the three-group economy when the rich group's human capital is improved, all the groups will economically benefit, and the leisure times of all the groups are reduced but when any other group's human capital is improved, the group will economically benefit, the other two groups economically lose, and the leisure times of all the groups are increased.

  1. Economic Model Predictive Control for Smart Energy Systems

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus

    Model Predictive Control (MPC) can be used to control the energy distribution in a Smart Grid with a high share of stochastic energy production from renewable energy sources like wind. Heat pumps for heating residential buildings can exploit the slow heat dynamics of a building to store heat...

  2. Model Coupling in Resource Economics: Conditions for Effective Interdisciplinary Collaboration

    NARCIS (Netherlands)

    MacLeod, Miles Alexander James; Nagatsu, Michiru

    2016-01-01

    In this article we argue for the importance of studying interdisciplinary collaborations by focusing on the role that good choice and design of model-building frameworks and strategies can play overcoming the inherent difficulties of collaborative research. We provide an empirical study of

  3. WASTES: a waste management logistics/economics model

    International Nuclear Information System (INIS)

    McNair, G.W.; Shay, M.R.; Fletcher, J.F.; Cashwell, J.W.

    1985-01-01

    The WASTES logistics model is a simulation language based model for analyzing the logistic flow of spent fuel/nuclear waste throughout the waste management system. The model tracks the movement of spent fuel/nuclear waste from point of generation to final destination. The model maintains inventories of spent fuel/nuclear waste at individual reactor sites as well as at various facilities within the waste management system. A maximum of 14 facilities may be utilized within a single run. These 14 facilities may include any combination of the following facilities: (1) federal interim storage (FIS), (2) reprocessing (REP), (3) monitored retrievable storage (MRS), (4) geological disposal facilities (GDF). The movement of spent fuel/nuclear waste between these facilities is controlled by the user specification of loading and unloading rates, annual and maximum capacities and commodity characteristics (minimum age or heat constraints) for each individual facility. In addition, the user may specify varying levels of priority on the spent fuel/nuclear waste that will be eligible for movement within a given year. These levels of priority allow the user to preferentially move spent fuel from reactor sites that are experiencing a loss of full-core-reserve (FCR) margin in a given year or from reactors that may be in the final stages of decommissioning. The WASTES model utilizes the reactor specific data available from the PNL spent fuel database. This database provides reactor specific information on items such as spent fuel basin size, reactor location, and transportation cask preference (i.e., rail or truck cask). In addition, detailed discharge data is maintained that provides the number of assemblies, metric tons, and exposure for both historic and projected discharges at each reactor site

  4. ECONOMY, ECONOMICS, ECONOMIC, ECONOMICAL

    Directory of Open Access Journals (Sweden)

    Sim Monica Ariana

    2013-07-01

    Full Text Available To speak and understand a language means - among many other things - knowing the words of that language. The average speaker knows, hears, understands and uses thousands of words daily. But does he use them appropriately? That is why this paper is about words and meanings. More specifically, it deals with the internal structure of complex words, i.e. derivatives. The purpose of the paper is to enable students and potentially other individuals dealing with English language on business basis to engage in their own analyses of some aspects of the language, namely the family tree of the word economy. After having read the paper, the reader should be familiar with the necessary knowledge regarding differences between meanings, misuse and actual sense of words deriving from economy, be able to systematically analyze data and relate his own findings on theoretical language problems. English is used by hundreds of millions speakers and still there is always need for improving our knowledge continuously. Knowing and speaking approximate English may not be enough at an advanced level as in the case of students who prepare themselves for careers that involve proficient communication in a foreign language on specific business issues. This is where the idea of such a paper appeared: students of the Faculty of Economic Sciences talk about economy and all the other terms deriving from it, with approximate knowledge of their meaning, without even being aware that some ‘minor' suffixes like –ic, -ical, -ics etc. really matter and do make a difference. Consequently, we started our teaching of Business English lecture in September 2012 with a working sheet based on the terms economic/ economical/ economics/ economy to assess students' awareness of these terms. The result was not a surprise as more than 90% misused economical instead of economic. That seemed a perfect introduction for students in economics. From that moment on, the building of their specific

  5. A model for the calculation of the off-site economic consequences of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Gallego, E.; Alonso, A.

    1988-01-01

    The off-site economic cost of nuclear reactor accidents will depend on the countermeasures adopted to reduce its radiological impact. The assessment of the direct costs of emergency countermeasures (evacuation, early relocation and food disposal) as well as those of long-term protective actions (food disposal, decontamination or interdiction) is the objective of a model under development, with the sponsorship of the CEC Radiation Protection Programme, called MECA (Model for assessing the Economic Consequences of Accidents). The meteorological and socio-economical peculiarities of each site studied will be taken into account, by means of a flexible meteorological sampling scheme, which considers the geographical distribution of population and economic centers, and a data-base, compatible with the existing European grid, that contains the population distribution and the economic characteristics of the environs of the site to be studied with more detail near the reactor. The paper summarizes the particular models which will be included in MECA and shows the importance of site-specific adaptable modelling for economic risk evaluation

  6. ERDYM: Economic Recovery Dynamics Model. Volume 1. Modifications and Simulations.

    Science.gov (United States)

    1984-05-01

    factors of production and demands. The use of input-output structure can improve the realism of the analysis, thus it can aid the formation of policies...follow a neoclassical approach. The second maior *0.1 structural change to ERDYM is the addition of a monetary sector structured so that interest rates...changes, the investment sector 4 * still remains a neoclassical model of optimum capital accumulation rather than -01 the investment sector originally

  7. Modelling Dynamics of Main Indicators of Economic Activity of Households of Ukraine

    Directory of Open Access Journals (Sweden)

    Zhuk Mykola O.

    2014-01-01

    Full Text Available The goal of the article is the study of the structure of the system of economic activity of households in Ukraine and dynamics of interconnections between the main indicators of its functioning. In order to study dynamics of main indicators of the system of economic activity of households, the article uses tools of econometric vector-autoregression modelling (VAR models. Based on the existing statistical data and a developed VAR model, the article studies individual and aggregate influence of lag values of indicators upon their current values, system reaction on main indicators impulses, analyses dynamics of change of explanation of dispersion of some indicators with others, and conducts two types of forecasts that reflect a general tendency of development of economic activity of households in Ukraine. High accuracy of forecasts obtained with the help of the proposed econometric model testifies to a possibility of its practical application for assessment of the state of main indicators of economic activity of households of Ukraine. The article applies for the first time the tools of VAR modelling for the study of economic activity of households in Ukraine, which expands possibilities of use of mathematical and statistical methods and models in this field of economy.

  8. Multi-Attribute Modelling of Economic and Ecological Impacts of Agricultural Innovations on Cropping Systems

    Directory of Open Access Journals (Sweden)

    Sara Scatasta

    2006-04-01

    Full Text Available Modeling of economic and ecological impacts of genetically modified crops is a demanding task. We present some models made for the purpose of the ECOGEN project "Soil ecological and economic evaluation of genetically modified crops". One of the goals of the project is to develop a computer-based decision support system for the assessment of economic and ecological impacts of using genetically modified crops, with special emphasis on soil biology and ecology. The decision support system is based on a rule-based model incorporating both economic and ecological criteria. In this paper we present an extension to previous results specifying further two sub-models assessing economic impacts of cropping systems at farm and regional level. Following a real option approach we show how both social and private costs and benefits, both at farm and regional level, can be classified in reversible and irreversible, and what irreversibility means for the size of the uncertainty associated to the adoption of agricultural innovations. All the qualitative models are developed using a qualitative multi-attribute modeling methodology, supported by the software tool DEXi.

  9. Economic modelling of energy services: Rectifying misspecified energy demand functions

    International Nuclear Information System (INIS)

    Hunt, Lester C.; Ryan, David L.

    2015-01-01

    Although it is well known that energy demand is derived, since energy is required not for its own sake but for the energy services it produces – such as heating, lighting, and motive power – energy demand models, both theoretical and empirical, often fail to take account of this feature. In this paper, we highlight the misspecification that results from ignoring this aspect, and its empirical implications – biased estimates of price elasticities and other measures – and provide a relatively simple and empirically practicable way to rectify it, which has a strong theoretical grounding. To do so, we develop an explicit model of consumer behaviour in which utility derives from consumption of energy services rather than from the energy sources that are used to produce them. As we discuss, this approach opens up the possibility of examining many aspects of energy demand in a theoretically sound way that have not previously been considered on a widespread basis, although some existing empirical work could be interpreted as being consistent with this type of specification. While this formulation yields demand equations for energy services rather than for energy or particular energy sources, these are shown to be readily converted, without added complexity, into the standard type of energy demand equation(s) that is (are) typically estimated. The additional terms that the resulting energy demand equations include, compared to those that are typically estimated, highlight the misspecification that is implicit when typical energy demand equations are estimated. A simple solution for dealing with an apparent drawback of this formulation for empirical purposes, namely that information is required on typically unobserved energy efficiency, indicates how energy efficiency can be captured in the model, such as by including exogenous trends and/or including its possible dependence on past energy prices. The approach is illustrated using an empirical example that involves

  10. An Innovative Economic Incentive Model for Improvement of the Working Environment in Europe

    DEFF Research Database (Denmark)

    Koch, Christian

    1997-01-01

    work injury compensation system, that a number of European countries operate. Building on an understanding of enterprise decision processes and ressources, it is suggested to implement a range of tools targetting different groups of enterprises. The central tools are bonus schemes, a special scheme......The design of economic incentive schemes to promote working environment embetterment has proven complicated. The contribution list some central preconditions and tools of an economic incentive model for improving the working environment. The economic incentive is proposed built into the compulsory...... for small enterprises, a marketing label and low interest investment aid. It is finally discussed what contrains the implementation of such a scheme can be confronted with....

  11. Energy-Environment interface: an economic model approach

    International Nuclear Information System (INIS)

    Glot-Sanchez, N.

    1995-01-01

    This thesis is separated in two parts. The first part has four chapters, from the first to the fourth one;the second part has four chapters, from the fifth to the eighth one. The first part describes an analysis of different areas about the subject: the energy sphere, the environmental sphere, the notion of external effects and environmental policy in terms of instruments. The second part is the analysis of the results of a model, aiming to determine the energy strategies in matter of electricity production and their investments to reduce carbon dioxide emissions. 181 refs

  12. Characterizing economic trends by Bayesian stochastic model specification search

    DEFF Research Database (Denmark)

    Grassi, Stefano; Proietti, Tommaso

    on whether their parameters are fixed or evolutive. Stochastic model specification is carried out to discriminate two alternative hypotheses concerning the generation of trends: the trend-stationary hypothesis, on the one hand, for which the trend is a deterministic function of time and the short run...... dynamics are represented by a stationary autoregressive process; the difference-stationary hypothesis, on the other, according to which the trend results from the cumulation of the effects of random disturbances. We illustrate the methodology for a set of U.S. macroeconomic time series, which includes...

  13. Innovation, Decentralization, and Planning in a Multi-Region Model of Schumpeterian Economic Growth

    OpenAIRE

    Batabyal, Amit; Nijkamp, Peter

    2014-01-01

    We study innovation and the resulting Schumpeterian economic growth that this innovation gives rise to in a model with N heterogeneous regions. For each region i where i=1,...,N, our analysis leads to five findings. First, we define the balanced growth path (BGP) allocations and the equilibrium of interest. Second, we stipulate the form of the innovation possibilities frontier that is consistent with balanced economic growth. Third, we derive the growth rate of the ith region in the decentral...

  14. ECONOMICAL OPTIMIZATION MODEL OF CONDENSING PLANTS CAPACITY MODERNIZED BY COMBINED-CYCLE TECHNOLOGY

    OpenAIRE

    S. G. Morozov

    2009-01-01

    Economic evaluation of combined-cycle technologies as main direction of power industry development is considered in the article. Analysis of Belarusian energy system operating mode is carried out. Economical optimization model of condensing plants capacity modernized by combined-cycle technology is suggested. In accordance with author’s approach optimal value of thermal power station modernization by combined-cycle technology is defined on basis of minimum-cost criterion. It is argued that in...

  15. Exports and economic growth in Indonesia's fishery sub-sector: Cointegration and error-correction models

    OpenAIRE

    Sjarif, Indra Nurcahyo; 小谷, 浩示; Lin, Ching-Yang

    2011-01-01

    This paper investigates the causal relationship between fishery's exports and its economic growth in Indonesia by utilizing cointegration and error-correction models. Using annual data from 1969 to 2005, we find the evidence that there exist the long-run relationship as well as bi-directional causality between exports and economic growth in Indonesia's fishery sub-sector. To the best of our knowledge, this is the first research that examine this issue focusing on a natural resource based indu...

  16. Modeling the Economic Incentives of DDoS Attacks: Femtocell Case Study

    Science.gov (United States)

    Segura, Vicente; Lahuerta, Javier

    Many of the Internet security incidents are caused by agents which act moved by economic incentives. When that is the case, it is possible to model at tacker's incentives by applying economics principles and, if we can collect appropriate data, we can use the model to have a better understanding of the risk imposed by these threats. This paper presents a simple model that represents the economic incentives for launching DDoS attacks against a specific telecommunications service. In addition, some data has been collected in order to quantify some of the variables of the model. Finally, some simulations have been performed to have a better knowledge of the risk of suffering this kind of attacks and propose solutions to mitigate it.

  17. Forecasting performances of three automated modelling techniques during the economic crisis 2007-2009

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl; Teräsvirta, Timo

    2014-01-01

    In this work we consider the forecasting of macroeconomic variables during an economic crisis. The focus is on a specific class of models, the so-called single hidden-layer feed-forward autoregressive neural network models. What makes these models interesting in the present context is the fact...... Scandinavian ones, and focus on forecasting during the economic crisis 2007–2009. The forecast accuracy is measured using the root mean square forecast error. Hypothesis testing is also used to compare the performances of the different techniques....... that they form a class of universal approximators and may be expected to work well during exceptional periods such as major economic crises. Neural network models are often difficult to estimate, and we follow the idea of White (2006) of transforming the specification and nonlinear estimation problem...

  18. Studies and research concerning BNFP. Identification and simplified modeling of economically important radwaste variables

    International Nuclear Information System (INIS)

    Ebel, P.E.; Godfrey, W.L.; Henry, J.L.; Postles, R.L.

    1983-09-01

    An extensive computer model describing the mass balance and economic characteristics of radioactive waste disposal systems was exercised in a series of runs designed using linear statistical methods. The most economically important variables were identified, their behavior characterized, and a simplified computer model prepared which runs on desk-top minicomputers. This simplified model allows the investigation of the effects of the seven most significant variables in each of four waste areas: Liquid Waste Storage, Liquid Waste Solidification, General Process Trash Handling, and Hulls Handling. 8 references, 1 figure, 12 tables

  19. Ecosystem-based fishery management: a critical review of concepts and ecological economic models

    DEFF Research Database (Denmark)

    Nguyen, Thanh Viet

      An ecosystem approach means different things to different people. As a result the concept of ecosystem-based fishery management is evolving and it has no universal definition or consistent application. As regards ecosystem modeling, most economic models of fishery ignore the linkages to lower...... trophic levels. In particular, environmental data and other bottom-up information is widely disregarded. The objective of this paper is to provide a critical review of concepts and ecological economic models relating to ecosystem-based fishery management....

  20. Economically optimized electricity trade modeling: Iran-Turkey case

    International Nuclear Information System (INIS)

    Shakouri, G.H.; Eghlimi, M.; Manzoor, D.

    2009-01-01

    The advantages of power trade between countries, which are attainable for various facts, are distinguished now. Daily differences in the peak-load times of neighboring countries commonly occur for differences in the longitudes of their location. Seasonal differences are also caused by differences in the latitudes leading to different climates. Consequently, different load curves help to have such a production schedule that reduces blackouts and investments for power generation by planning for a proper trade between countries in a region. This paper firstly describes the methodology and framework for the power trade and then the results of an optimal power trade model between Iran and Turkey, which shows a potential benefit for both countries by peak shaving, are presented. The results, in the worst case design, represent optimality of about 1500 MW electricity export from Iran to Turkey at the Turkish peak times, as well as 447 MW electricity import from Turkey at the Iranian peak times. In addition, results derived from running a Long-Run model show that there will be greater potential for power export from Iran to Turkey, which is a guideline of an energy conservation strategy for both countries in the future

  1. A reformulation of the Cost Plus Net Value Change (C+NVC) model of wildfire economics

    Science.gov (United States)

    Geoffrey H. Donovan; Douglas B. Rideout

    2003-01-01

    The Cost plus Net Value Change (C+NVC) model provides the theoretical foundation for wildland fire economics and provides the basis for the National Fire Management Analysis System (NFMAS). The C+NVC model is based on the earlier least Cost plus Loss model (LC+L) expressed by Sparhawk (1925). Mathematical and graphical analysis of the LC+L model illustrates two errors...

  2. MODEL EVALUATION OF THE SPATIAL DEVELOPMENT OF THE REGION THROUGH THE DEVELOPMENT OF REGIONAL ECONOMIC CLUSTERS

    Directory of Open Access Journals (Sweden)

    Чингис Дашидалаевич Дашицыренов

    2013-12-01

    Full Text Available The article describes a model of evaluation of effectiveness of spatial development of a region. Main approaches and criteria to assess effectiveness of socio-economic development of a region based on use of regional economic cluster are identified.The author believes that clusterization allows to eliminate or localize mentioned above restrictions which are characteristic of specific activity of entities. Effect in this case can be measured by increase in productivity obtained from cluster’s resources use  in regard to specific form of enterprises’ existence.The article also focused on definition of idea of synergic effect and the model of effectiveness of clusters. Cluster integration’s essence is considered – it is pointed out that a new structure is formed, which has emergent characteristics.Thus, main approach to spatial socio-economic development of a region proposed by the author is diversification of organizational and economic forms into regional economic clusters.Proposed by the author model allows to assess effectiveness of clusterization for spatial socio-economic development of any region. DOI: http://dx.doi.org/10.12731/2218-7405-2013-10-14

  3. Emergent behavior in a coupled economic and coastline model for beach nourishment

    Directory of Open Access Journals (Sweden)

    E. D. Lazarus

    2011-12-01

    Full Text Available Developed coastal areas often exhibit a strong systemic coupling between shoreline dynamics and economic dynamics. "Beach nourishment", a common erosion-control practice, involves mechanically depositing sediment from outside the local littoral system onto an actively eroding shoreline to alter shoreline morphology. Natural sediment-transport processes quickly rework the newly engineered beach, causing further changes to the shoreline that in turn affect subsequent beach-nourishment decisions. To the limited extent that this landscape/economic coupling has been considered, evidence suggests that towns tend to employ spatially myopic economic strategies under which individual towns make isolated decisions that do not account for their neighbors. What happens when an optimization strategy that explicitly ignores spatial interactions is incorporated into a physical model that is spatially dynamic? The long-term attractor that develops for the coupled system (the state and behavior to which the system evolves over time is unclear. We link an economic model, in which town-manager agents choose economically optimal beach-nourishment intervals according to past observations of their immediate shoreline, to a simplified coastal-dynamics model that includes alongshore sediment transport and background erosion (e.g. from sea-level rise. Simulations suggest that feedbacks between these human and natural coastal processes can generate emergent behaviors. When alongshore sediment transport and spatially myopic nourishment decisions are coupled, increases in the rate of sea-level rise can destabilize economically optimal nourishment practices into a regime characterized by the emergence of chaotic shoreline evolution.

  4. Modelling and economic evaluation of forest biome shifts under climate change in Southwest Germany

    Science.gov (United States)

    Marc Hanewinkel; Susan Hummel; Dominik. Cullmann

    2010-01-01

    We evaluated the economic effects of a predicted shift from Norway spruce (Picea abies) to European beech (Fagus sylvatica) for a forest area of 1.3 million ha in southwest Germany. The shift was modelled with a generalized linear model (GLM) by using presence/absence data from the National Forest Inventory in Baden-Wurttemberg...

  5. Model Proposition for the Fiscal Policies Analysis Applied in Economic Field

    Directory of Open Access Journals (Sweden)

    Larisa Preda

    2007-05-01

    Full Text Available This paper presents a study about fiscal policy applied in economic development. Correlations between macroeconomics and fiscal indicators signify the first steep in our analysis. Next step is a new model proposal for the fiscal and budgetary choices. This model is applied on the date of the Romanian case.

  6. Introducing labour productivity changes into models used for economic impact analysis in tourism

    NARCIS (Netherlands)

    Klijs, Jeroen; Peerlings, Jack; Heijman, Wim

    2017-01-01

    In tourism management, traditional input-output models are often applied to calculate economic impacts, including employment impacts. These models imply that increases in output are translated into proportional increases in labour, indicating constant labour productivity. In non-linear input-

  7. Colocalization of low-methylesterified pectins and Pb deposits in the apoplast of aspen roots exposed to lead

    International Nuclear Information System (INIS)

    Rabęda, Irena; Bilski, Henryk; Mellerowicz, Ewa J.; Napieralska, Anna; Suski, Szymon; Woźny, Adam; Krzesłowska, Magdalena

    2015-01-01

    Low-methylesterified homogalacturonans have been suggested to play a role in the binding and immobilization of Pb in CW. Using root apices of hybrid aspen, a plant with a high phytoremediation potential, as a model, we demonstrated that the in situ distribution pattern of low-methylesterified homogalacturonan, pectin epitope (JIM5-P), reflects the pattern of Pb occurrence. The region which indicated high JIM5-P level corresponded with “Pb accumulation zone”. Moreover, JIM5-P was especially abundant in cell junctions, CWs lining the intercellular spaces and the corners of intercellular spaces indicating the highest accumulation of Pb. Furthermore, JIM5-P and Pb commonly co-localized. The observations indicate that low-methylesterified homogalacturonan is the CW polymer that determines the capacity of CW for Pb sequestration. Our results suggest a promising directions for CW modification for enhancing the efficiency of plant roots in Pb accumulation, an important aspect in the phytoremediation of soils contaminated with trace metals. - Highlights: • Co-localization of low-methylesterified pectins and Pb was analysed in situ. • The pattern of Pb accumulation matched low-methylesterified pectins distribution. • Low-methylesterified pectins and Pb commonly co-localized in cell walls. • Low-methylesterified pectins revealed an important compound in Pb sequestration. • We suggest a new direction in enhancing plant efficiency for phytoremediation. - The distribution of lead in developing tissues of aspen root tips exposed to short-term lead treatment mimics the distribution of low-methylesterified pectin epitope

  8. Periodical Economics

    OpenAIRE

    King, Andrew

    2016-01-01

    This is the first overview of the economics of nineteenth-century periodicals and newspapers. While media economics is an established field in business studies, the chapter redefines economics by looking at value systems including capitalist ones but no confined to them. Original case studies are offered as models for research into the economics of nineteenth-century print culture.

  9. Is the wide distribution of aspen a result of its stress tolerance?

    Science.gov (United States)

    V. J. Lieffers; S. M. Landhausser; E. H. Hogg

    2001-01-01

    Populus tremuloides is distributed from drought-prone fringes of the Great Plains to extremely cold sites at arctic treeline. To occupy these conditions aspen appears to be more tolerant of stress than the other North American species of the genus Populus. Cold winters, cold soil conditions during the growing season, periodic drought, insect defoliation, and...

  10. Risk Communication, Metacommunication, and Rhetorical Stases in the Aspen-EPA Superfund Controversy.

    Science.gov (United States)

    Stratman, James F.; And Others

    1995-01-01

    Explores the relationship between current theoretical definitions of risk communication, the unique national role that EPA plays in defining health and environmental risks, and possible explanations for EPA's inability to persuade Aspen, Colorado, to accept a cleanup plan. Explores ownership messages conveyed through metacommunication conflict…

  11. Polypropylene /Aspen/ liquid polybutadienes composites: maximization of impact strength, tensile and modulus by statistical experimental design

    Czech Academy of Sciences Publication Activity Database

    Kokta, B. V.; Fortelný, Ivan; Kruliš, Zdeněk; Horák, Zdeněk; Michálková, Danuše

    2005-01-01

    Roč. 99, - (2005), s. 10-11 ISSN 0009-2770. [International Conference on Polymeric Materials in Automotive , Slovak Rubber Conference /17./. 10.5.2005-12.5.2005, Bratislava] Institutional research plan: CEZ:AV0Z40500505 Keywords : polypropylene * Aspen-PP composite Subject RIV: CD - Macromolecular Chemistry

  12. Pine hollow exclosures: Effect of browsing on an aspen community sprayed with 2,4-D

    Science.gov (United States)

    Dale L. Bartos; Roy O. Harniss

    1990-01-01

    The Pine Hollow aspen (Populus tremuloides) exclosures on the Ashley National Forest in eastern Utah were sampled in 1984, 19 years after they were established. The effects of 2,4-D, wildlife, and cattle on plant succession were evaluated. Two exclosures were used to protect the sprayed area from (1) all animal use and (2) only livestock use. A third sprayed area was...

  13. ASPEN Plus in the Chemical Engineering Curriculum: Suitable Course Content and Teaching Methodology

    Science.gov (United States)

    Rockstraw, David A.

    2005-01-01

    An established methodology involving the sequential presentation of five skills on ASPEN Plus to undergraduate seniors majoring in ChE is presented in this document: (1) specifying unit operations; (2) manipulating physical properties; (3) accessing variables; (4) specifying nonstandard components; and (5) applying advanced features. This…

  14. Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens (Populus × smithii).

    Science.gov (United States)

    Deacon, Nicholas John; Grossman, Jake Joseph; Schweiger, Anna Katharina; Armour, Isabella; Cavender-Bares, Jeannine

    2017-12-01

    Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant Populus tremuloides populations. Pleistocene hybridization between P. tremuloides and P. grandidentata has been proposed, but the nearest P. grandidentata populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically. We compared nuclear microsatellite loci and chloroplast sequences of Niobrara River aspens to their putative parental species. Parental species and putative hybrids were also grown in a common garden for phenotypic comparison. On the common garden plants, we measured leaf morphological traits and leaf-level spectral reflectance profiles, from which chemical traits were derived. The genetic composition of the three unique Niobrara aspen genotypes is consistent with the hybridization hypothesis and with maternal chloroplast inheritance from P. grandidentata . Leaf margin dentition and abaxial pubescence differentiated taxa, with the hybrids showing intermediate values. Spectral profiles allowed statistical separation of taxa in short-wave infrared wavelengths, with hybrids showing intermediate values, indicating that traits associated with internal structure of leaves and water absorption may vary among taxa. However, reflectance values in the visible region did not differentiate taxa, indicating that traits related to pigments are not differentiated. Both genetic and phenotypic results support the hypothesis of a hybrid origin for these genetically unique aspens. However, low genetic diversity and ongoing ecological and climatic threats to the hybrid taxon present a challenge for conservation of these relictual boreal communities. © 2017 Botanical Society of America.

  15. Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

    Science.gov (United States)

    Edward L. Springer; John F. Harris

    1982-01-01

    Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

  16. Comparisons of SPORL and dilute acid pretreatments for sugar and ethanol productions from aspen

    Science.gov (United States)

    S. Tian; W. Zhu; Roland Gleisner; X.J. Pan; Junyong Zhu

    2011-01-01

    This study reports comparative evaluations of sugar and ethanol production from a native aspen (Populus tremuloides) between sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL) and dilute acid (DA) pretreatments. All aqueous pretreatments were carried out in a laboratory wood pulping digester using wood chips at 170°C with a liquid to...

  17. Using Aspen to Teach Chromatographic Bioprocessing: A Case Study in Weak Partitioning Chromatography for Biotechnology Applications

    Science.gov (United States)

    Evans, Steven T.; Huang, Xinqun; Cramer, Steven M.

    2010-01-01

    The commercial simulator Aspen Chromatography was employed to study and optimize an important new industrial separation process, weak partitioning chromatography. This case study on antibody purification was implemented in a chromatographic separations course. Parametric simulations were performed to investigate the effect of operating parameters…

  18. Root growth and physiology of potted and field-grown trembling aspen exposed to tropospheric ozone

    Science.gov (United States)

    M.D. Coleman; R.E. Dickson; J.G. Isebrands; D.F. Karnosky

    1996-01-01

    We studied root growth and respiration of potted plants and field-grown aspen trees (Populus tremuloides Michx.) exposed to ambient or twice-ambient ozone. Root dry weight of potted plants decreased up to 45% after 12 weeks of ozone treatment, and root system respiration decreased by 27%. The ozone-induced decrease in root system respiration of...

  19. Lake States Aspen Productivity Following Soil Compaction and Organic Matter Removal

    Science.gov (United States)

    Douglas M. Stone

    2002-01-01

    Aspen (Populus tremuloides Michx. and P. grandidentata Michx.) provides wood products, watershed protection, and wildlife habitat for numerous game and non-game species across the northern Great Lakes region. Sustaining the productivity of these ecosystems requires maintaining soil productivity. Management activities that decrease...

  20. Molecular population genetics of elicitor-induced resistance genes in European aspen (Populus tremula L., Salicaceae.

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    Carolina Bernhardsson

    Full Text Available Owing to their long life span and ecological dominance in many communities, forest trees are subject to attack from a diverse array of herbivores throughout their range, and have therefore developed a large number of both constitutive and inducible defenses. We used molecular population genetics methods to examine the evolution of eight genes in European aspen, Populus tremula, that are all associated with defensive responses against pests and/or pathogens, and have earlier been shown to become strongly up-regulated in poplars as a response to wounding and insect herbivory. Our results show that the majority of these defense genes show patterns of intraspecific polymorphism and site-frequency spectra that are consistent with a neutral model of evolution. However, two of the genes, both belonging to a small gene family of polyphenol oxidases, show multiple deviations from the neutral model. The gene PPO1 has a 600 bp region with a highly elevated K(A/K(S ratio and reduced synonymous diversity. PPO1 also shows a skew toward intermediate frequency variants in the SFS, and a pronounced fixation of non-synonymous mutations, all pointing to the fact that PPO1 has been subjected to recurrent selective sweeps. The gene PPO2 shows a marked excess of high frequency, derived variants and shows many of the same trends as PPO1 does, even though the pattern is less pronounced, suggesting that PPO2 might have been the target of a recent selective sweep. Our results supports data from both Populus and other species which have found that the the majority of defense-associated genes show few signs of selection but that a number of genes involved in mediating defense against herbivores show signs of adaptive evolution.