Consulta: subjectFacets:"Equilibrium"
Registros recuperados: 22
Data/hora: 10/06/2024 07:48:35

Biosorption of uranium from aqueous solutions by nonliving biomass of marinealgae Cystoseira indica
Provedor de dados: 69
Autores: Hassan Khani,Mohammad; Reza Keshtkar,Ali; Meysami,Behrouz; Firouz Zarea,Mohammad; Jalali,Reza.
Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions. In this paper uranium biosorption by protonated, Ca-pretreated and non-pretreated Cystoseira indica algae biomass was investigated in a batch system. The results of the kinetic studies showed that the sorption of uranium on protonated and non-pretreated biomass followed pseudo-second order kinetics. The effect of pH on the equilibrium uranium sorption capacity of Cystoseira indica exhibited that highest uptake occurred at pH 4 at a solution with 350 mg/l uranium concentration. At various initial uranium concentrations from 50 to 1000 mg/l, batch sorption equilibrium at 30&amp;ordm;C was reached within 3 hrs and the sorption...
Tipo: Journal article
Palavras-chave: Biosorption; Cystoseira indica; Equilibrium; Kinetic; Marine algae; Uranium.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000200003

Effects of biosorption parameter: kinetics, isotherm and thermodynamics for Ni(II) biosorption from aqueous solution by Circinella sp.
Provedor de dados: 69
Autores: Alpat,Senol; Alpat,Sibel Kilinç; Çadirci,Bilge Hilal; Özbayrak,Özge; Yasa,Ihsan.
Circinella sp. was employed as a biosorbent for removal of Ni(II) from aqueous solution. The biosorption kinetics and isotherms were investigated. The effect of several parameters, such as biosorbent dosage, contact time, initial concentration, pH and temperature, on biosorption process was evaluated. The kinetic studies indicated that the biosorption followed pseudo-second order kinetic model. Biosorption behaviour of Ni(II) on Circinella sp. was expressed by both Langmuir and Freundlich isotherms. The equilibrium data fit better to the Langmuir model compared to the Freundlich model in concentration range studied (1.0-3.0 mM). The thermodynamic parameters (&amp;#916;G0, &amp;#916;H0 and &amp;#916;S0) were also determined, and it was found that the Ni(II)...
Tipo: Journal article
Palavras-chave: Biosorption; Circinella sp; Equilibrium; Kinetic; Nickel.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000500004

Biosorption of lead(II) and chromium(VI) on groundnut hull: Equilibrium, kinetics and thermodynamics study
Provedor de dados: 69
Autores: Qaiser,Suleman; Saleemi,Anwar R; Umar,Muhammad.
The biosorption of lead(II) and chromium(VI) on groundnut hull was investigated. Batch biosorption experiments were conducted to find the equilibrium time and biosorption capacity. Effect of parameters like pH, temperature and initial metal concentration was studied. The maximum biosorption capacity of lead(II) and chromium(VI) was found to be 31.54 ± 0.63 and 30.21 ± 0.74 mg g-1, respectively. The optimum pH for lead(II) and chromium(VI) removal was 5 ± 0.1 and 2 ± 0.1, respectively. The temperature change, in the range of 20 - 45ºC affected the biosorption capacity. The maximum removal of lead(II) was achieved at 20 ± 2ºC, where as maximum uptake of chromium(VI) was observed at 40 ± 2ºC. The biosorption data was fitted to the Langmuir and the Freundlich...
Tipo: Journal article
Palavras-chave: Biosorption; Equilibrium; Groundnut hull; Kinetics; Thermodynamics.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000400003

Ecological-economic modelling for the sustainable management of biodiversity
Provedor de dados: 5
Autores: Doyen, Luc; Cisse, Abdoul; Gourguet, Sophie; Mouysset, L.; Hardy, Pierre-yves; Bene, Christophe; Blanchard, Fabian; Jiguet, Frederic; Pereau, J.-c.; Thebaud, Olivier.
Terrestrial and marine biodiversity provides the basis for both ecosystems functioning and numerous commodities or services that underpin human well-being. From several decades, alarming trends have been reported worldwide for both biodiversity and ecosystem services. Therefore the sustainable management of biodiversity requires a double viewpoint balancing ecological conservation with the welfare of human societies. Understanding the underlying trade-offs, synergies and interactions imposes the development of interdisciplinary researches and methods. In that respect, bio-economic or ecological economic modeling is likely to play a major role. The present paper intends to elicit the key features, strengths and challenges of bio-economic approaches...
Tipo: Text
Palavras-chave: Ecological economics; Modeling; Sustainability; Biodiversity; Public policy; Criterion; Equilibrium; Optimality; Viability.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00171/28208/26510.pdf

Using SAM's to account for distortions in non-market economies
Provedor de dados: 31
Autores: Adelman,   Irma; Berck,   Peter; Vujovic,   Dusan.
Tipo: Working or Discussion Paper
Palavras-chave: Economic conditions; Economic development; Economics; Equilibrium; Investments; Sam.
Ano: 1991
URL: http://purl.umn.edu/43741

Relationship of the Interests between the Dairy Farmer and the Company in Ecological Agriculture  －A Case of the Dairy Industry in Sichuan Province, China
Provedor de dados: 31
Autores: Chen,   Jia-Wei; Qi,   Yan-bin.
Development status of dairy industry in Sichuan Province, China is analyzed, indicating that how to ensure the high-quality and ecological production of peasant households has become an important issue for the safety and healthy of the masses and the development of dairy industry. Game model is established and the solution for the model is obtained. Based on analyzing the relationship of the interests between the dairy farmer and the company in ecological agriculture, two mixed strategies of Nash equilibrium are obtained. One is that when the probability is equal to  , there are no differences between purchasing or not purchasing; if the probability of company purchase is equal to , there are no differences between producing high-quality milk and...
Tipo: Journal Article
Palavras-chave: Game theory; Equilibrium; High quality milking; Moral risk; China; Agribusiness.
Ano: 2010
URL: http://purl.umn.edu/97625

Limited Food Access as an Equilibrium Outcome: An Empirical Analysis
Provedor de dados: 31
Autores: Bonanno,   Alessandro; Chenarides,   Lauren; Goetz,   Stephan J.
Lack of access to nutritious and affordable food has become an important public policy issue in the U.S.: various interest groups are seeking to reverse a trend whereby certain areas lack larger, full-service grocery stores that provide “higher” quality foods. Based on game-theoretic findings suggesting that lack of food access can be an equilibrium outcome, we specify a model relating access to higher quality food stores to a vector of supply and demand factors, using seven years of county-level data for the contiguous U.S., and a constrained generalized ordered logit estimator. Our results suggest that demand side factors, especially market size (total income and SNAP funds) play an important role in determining food access, and that large food stores...
Tipo: Presentation
Palavras-chave: Food Access; Equilibrium; Food-Store Density; Food Consumption/Nutrition/Food Safety; Q18; R3; L81.
Ano: 2012
URL: http://purl.umn.edu/123196

Reworking the Standard Model of Competitive Markets: The Role of Fuzzy Logic and Genetic Algorithms in Modelling Complex Non-Linear Economic System
Provedor de dados: 31
Autores: Smith,   Peter.
Some aspects of economic systems (eg, nonlinearity, qualitative variables) are intractable when incorporated into models. The widespread practice of excluding them (or greatly limiting their role) produces deviations of unknown size and form between the resulting models and the reality they purport to represent. To explore this issue, and the extent to which a change in methodology can improve tractability, a combination of two techniques, fuzzy logic and genetic algorithms, was applied to the problem of how the sellers in a freely competitive market, if initially trading at different prices, can find their way to supply/demand equilibrium. A multi-agent model was used to simulate the evolution of autonomously- learnt rule-governed behaviour, (i), under...
Tipo: Working or Discussion Paper
Palavras-chave: Competition; Markets; Walrasian Crier; Equilibrium; Fuzzy logic; Genetic algorithms; Evolutionary algorithms; Industrial Organization.
Ano: 2004
URL: http://purl.umn.edu/30569

Can market power be estimated?
Provedor de dados: 31
Autores: Hyde,   Charles Evan; Perloff,   Jeffrey M.
Tipo: Working or Discussion Paper
Palavras-chave: Economics; Equilibrium; Marketing; Supply and demand; Marketing.
Ano: 1993
URL: http://purl.umn.edu/47275

Tariffs and quotas that lower prices and raise welfare
Provedor de dados: 31
Autores: Perloff,   Jeffrey M.
Tipo: Working or Discussion Paper
Palavras-chave: Consumers; Economics; Equilibrium; Import; Quotas; International Relations/Trade; Food Security and Poverty.
Ano: 1993
URL: http://purl.umn.edu/47254

Equilibrium of Land Values from Agricultural and General Economic Factors for Cropland and Pasture Capitalization in Georgia
Provedor de dados: 31
Autores: Flanders,   Archie; White,   Fred C.; Escalante,   Cesar L.
Nonagricultural factors impact land values to cause a divergence of discounted cash rents for agricultural land and land values in Georgia. General economic factors are represented by per capita income in nonmetro areas. Cash rents for cropland and pasture have positive impacts on land values. Nonagricultural factors are stronger influences on land values than are cash rents. Greater effective demand exists for pasture than for cropland because pasture is subject to relatively more pricing pressure in northern counties with higher incomes and population. Increased land values have led to increased net wealth for Georgia agricultural producers.
Tipo: Journal Article
Palavras-chave: Capitalization; Cash rent; Cointegration; Equilibrium; Error correction mechanism; Land values; Land Economics/Use.
Ano: 2004
URL: http://purl.umn.edu/59605

Firm-specific information, product differentiation, and industry equilibrium
Provedor de dados: 31
Autores: Perloff,   Jeffrey M.; Salop,   Steven.
Where consumers have imperfect information about specific firms’ prices and lack information about the market, firms have informational market power. In general, improving the consumer’s information about each firm’s price will not necessarily lower average market price. We show, however, that certain types of improvements will lower price. Moreover, a reduction in barriers to entry (e.g., capital costs) will lower price-holding information constant. Where a significant number (but not all) consumers have perfect information, single-price equilibria are impossible.
Tipo: Working or Discussion Paper
Palavras-chave: Competition; Consumers; Consumers' preferences; Consumer education; Mathematical models; Demand elasticity; Economics; Equilibrium; Marketing; Consumer/Household Economics; Demand and Price Analysis.
Ano: 1985
URL: http://purl.umn.edu/47003

Competition, Kinship or Reciprocity? Village Experiments in Alternative Modes of Exchange
Provedor de dados: 31
Autores: Subramanian,   Arjunan; Qaim,   Matin.
In this paper, detailed data on transactions in a village commodity market are used to explain the puzzle of sluggish agricultural supply response. We show that existence of reciprocity among sellers exhibits multiple equilibria and creates trade diversion. Large volumes of the commodity are sold to a trader who does not offer the best price, but on whom sellers depend through transactions in other markets. An implication of this trader-idiosyncratic effect on supply is that policies that affect prices may result in different supply responses.
Tipo: Conference Paper or Presentation
Palavras-chave: Reciprocity; Kinship; Neighborhood effects; Trader idiosyncrasy; Equilibrium; Consumer/Household Economics.
Ano: 2006
URL: http://purl.umn.edu/25434

Why industrial policies fail: limited commitment
Provedor de dados: 31
Autores: Karp,   Larry S.; Perloff,   Jeffrey M.
The strategic effects of subsidies on output and subsidies on investment differ substantially in dynamic models where a government's commitment ability is limited. Output subsidies remain effective even as the period of commitment vanishes, but investment subsidies may become completely ineffective. This difference has been obscured because most existing models of strategic trade policy are static.
Tipo: Working or Discussion Paper
Palavras-chave: Consumers; Economics; Equilibrium; Export subsidies; Investments; Trade agreements; International Relations/Trade.
Ano: 1993
URL: http://purl.umn.edu/47044

The effect of tariffs in markets with vertical restraints
Provedor de dados: 31
Autores: Fargeix,   Andre; Perloff,   Jeffrey M.
Tipo: Working or Discussion Paper
Palavras-chave: Competition; Economics; Equilibrium; Marketing; Mathematical models; Monopolies; Tariff; Welfare economics; Marketing; International Relations/Trade.
Ano: 1987
URL: http://purl.umn.edu/47040

AN EQUILIBRIUM ANALYSIS OF THE IMPACT OF ANTIBIOTICS BANS ON INVESTMENT IN APPLE ORCHARDS
Provedor de dados: 31
Autores: Hennessy,   David A.; Roosen,   Jutta.
The decision to replant a fire blight-susceptible apple orchard is analyzed.  Embedding the problem into an equilibrium framework facilitates the welfare analysis of changes in orchard survival probabilities arising from a ban on antibiotics use.  We estimate the structural impacts and welfare changes of the ban.
Tipo: Conference Paper or Presentation
Palavras-chave: Antibiotics; Apple orchard; Dynamics; Equilibrium; Replanting; Resistance; Truncated Poisson process; Environmental Economics and Policy; Research and Development/Tech Change/Emerging Technologies.
Ano: 1999
URL: http://purl.umn.edu/21698

Agrarökonomik zur Jahrhundertwende – Bewährtes und Unorthodoxes
Provedor de dados: 31
Autores: Brandes,   Wilhelm.
In this farewell lecture some concepts important for (agricultural) economics are discussed. Special emphasis is given to the Invisible Hand of Adam Smith, sunk costs, information economics, path dependency, error tolerance and redundancy. It is proposed that agricultural economists follow closely new developments in economics proper.
Tipo: Journal Article
Palavras-chave: Equilibrium; Sunk costs; Game theory; Opportunism; Rationality; Path dependency; Error tolerance; Social rate of discount; Agricultural and Food Policy; Teaching/Communication/Extension/Profession.
Ano: 2001
URL: http://purl.umn.edu/99010

Rainfall or Price Variability: What Determines Rangeland Management Decisions? A Simulation-Optimization Approach to South African Savannas
Provedor de dados: 31
Autores: Börner,   Jan; Higgins,   Steven Ian; Kantelhardt,   Jochen; Scheiter,   Simon.
Savannas cover the greater part of Africa and Australia and almost half of South America and contribute to the livelihoods of more than 350 million people. With the intensification of land use during the second half of the 20th century, savannas have become increasingly degraded through bush encroachment as a consequence of increased grazing pressure. Research on rangeland dynamics, however, provides contradicting answers with regard to the causes and possible remedies of bush encroachment. In this paper we present results from an application of a simulation-optimization model to the case of extensive rangeland management in South Africa. Our model differs from previous approaches in that it explicitly accounts for the influence of stochastic prices and...
Tipo: Conference Paper or Presentation
Palavras-chave: Equilibrium; Bio-economic modeling; Grassland management; Sustainable strategies; Stochastic conditions; Livestock Production/Industries; Q57.
Ano: 2006
URL: http://purl.umn.edu/25435

Price Relationships in the U.S. Tree Nut Market
Provedor de dados: 31
Autores: Ibrahim,   Mohammed; Florkowski,   Wojciech J.
Although most U.S. tree nuts have very specific and different uses, some substitutability does occur, complicating the price analysis in the tree nut market. We examine the relationships among U.S. tree nut prices using the Johansen’s cointegration procedure. We found long run equilibrium among some nut prices, namely, pecans, walnuts, and almonds. These findings are consistent with recent suggestions that cointegration exist among substitutes.
Tipo: Conference Paper or Presentation
Palavras-chave: Substitutability; Cointegration; Tree nuts; Long-run; Equilibrium; Demand and Price Analysis; Marketing.
Ano: 2007
URL: http://purl.umn.edu/9898

Hedging with a housing starts futures contract
Provedor de dados: 31
Autores: Berck,   Peter; Rosen,   Kenneth T.
Tipo: Working or Discussion Paper
Palavras-chave: Economics; Equilibrium; Future trading.
Ano: 1984
URL: http://purl.umn.edu/43307

Adjustment under different trade strategies: a mean-variance analysis with a CGE model of the Yugoslav economy
Provedor de dados: 31
Autores: Adelman,   Irma; Berck,   Peter; Labus,   Miroljub; Vujovic,   Dusan.
Tipo: Working or Discussion Paper
Palavras-chave: Commerce; Economics; Equilibrium; Sam.
Ano: 1990
URL: http://purl.umn.edu/43667

The globalized thought process in relation to natural resources
Provedor de dados: 42
Autores: SWING,KELLY.
Abstract: To understand the increasingly tenuous relationship between ourselves and the finite resource base upon which we depend for all sustenance, an exploration of recent history and basic human behavior is warranted. An attempt is made to shed light on how short-term economic demands have come to take priority over nearly all other long-term aspects of our existence. Without full recognition of our historical and cultural trajectories in relation to the modern mass mentality of materialism, consumerism and wealth, there is little possibility to develop or implement truly functional strategies that can be utilized indefinitely.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Balance; Equilibrium; Logic; Mentality; Natural resources; Thought process.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000600609