Search results for "Dynamic"
showing 10 items of 12329 documents
Anaerobic dynamic membrane bioreactors for high strength wastewater treatment
2013
A laboratory scale external anaerobic dynamic membrane bioreactor (AnDMBR) treating high strength wastewater was operated to assess the effect of gas sparging velocity and organic loading rate on removal efficiency and dynamic membrane (DM) filtration characteristics. An increase in gas sparging velocity (GSV) results in a decrease in DM filtration resistance. DM or cake formation was identified as the main contribution to the total filtration resistance. Over 99% COD removal was obtained in the study regardless of the GSV. The results showed that the DM formation process proceeded until a stable cake layer thickness was reached. An effective pollutant removal and high permeate quality was …
Transient stability simulation of a fixed speed wind turbine by Matlab/Simulink
2007
This paper describes the dynamic behavior of a typical fixed speed wind turbine connected to the grid; the model is developed in the simulation tool Matlab/Simulink and created as a modular structure. The pitch control system is used for stabilization of the wind turbine at grid faults. In this way, voltage stability of the system with grid-connected wind turbines can be improved by using blade-angle control for a temporary reduction of the wind turbine power during a short-circuit fault in the grid. This paper shows a new variable control for maintaining of voltage stability, when a three-phase fault is applied close to the wind turbine and cleared by disconnecting the affected line. In th…
Change Is Good, But Not Too Much: Dynamic Positioning in the Interfirm Network and New Product Development
2018
This research considers the dynamic positioning of an enterprise in an interfirm network and its propensity for new product development. Specifically, we explore how firms reconcile the dichotomy between central and structural holes network positions, by dynamically shifting from a central to a structural holes position (and vice versa) over time. By grounding this research in network dynamics theory, we argue how prior strong central (structural holes) network positions in the interfirm network increase the likelihood the firm will benefit from structural holes (central) positions in the following time period. We also propose that these positions can be modeled by an inverted U-shaped rela…
The upcoming rise of SMEs in cross-border public procurement: is it a matter of networking capabilities?.
2022
La participación de las SME en licitaciones públicas es un tema recurrente en la literatura académica reciente, sin embargo, se ha prestado poca atención a la participación de las PYME en licitaciones internacionales o transfronterizas. Las SME que quieren participar en una licitación pública internacional debe superar barreras internas y externas que difcultan la tarea y minimizan las posibilidades de que le sea concedida la licitación. En este contexto, las capacidades dinámicas son fundamentales para que las PYME puedan enfrentarse y resolver dichas barreras en el contexto internacional. Especialmente son las capacidades de establecer redes las que pueden hacer que las PYME aumenten su d…
The dynamics of aroma release during consumption of candies of different structures, and relationship with temporal perception
2011
; We investigated the role of both candy texture and eating technique (melting or chewing) on the dynamics of aroma release. One novelty of this type of analysis was the simultaneous application of instrumental and sensory analysis. Four candy textures were established based on their storage modulus at 1 Hz by varying the gelatine content between 0 and 15% w/w. The in vivo release of three aroma compounds was monitored using Proton Transfer Reaction Mass Spectrometry and with a trained panel of testers. The gelatine content had no significant effect on the headspace/product partition and diffusion properties of the aroma compounds. The highest in vivo release for all aroma compounds was ob…
A mate to die for? A model of conditional monogyny in cannibalistic spiders.
2012
Monogynous males in various species actively limit themselves to mating with a single female in their lifetime. Whereas previous models have considered monogyny as an obligate mating strategy, here we explore the potential of monogyny to evolve as a context-specific (conditional) behavior. Using a state-dependent dynamic game model based on the biology of the cannibalistic spider Argiope bruennichi, we confirm that conditional monogyny can evolve under broad conditions, including an even sex ratio. We predict that males should make a terminal investment when mating with large, virgin females, especially if population density is low and the encounter occurs late in the season. We encourage e…
Scenario modeling for the management of international bond portfolios
1998
We address the problem of portfolio management in the international bond markets. Interest rate risk in the local market, exchange rate volatility across markets, and decisions for hedging currency risk are integral parts of this problem. The paper develops a stochastic programming optimization model for integrating these decisions in a common framework. Monte Carlo simulation procedures, calibrated using historical observations of volatility and correlation data, generate jointly scenarios of interest and exchange rates. The decision maker's risk tolerance is incorporated through a utility function, and additional views on market outlook can also be incorporated in the form of user specifi…
A mate to die for? A model of conditional monogyny in cannibalistic spiders
2012
Monogynous males in various species actively limit themselves to mating with a single female in their lifetime. Whereas previous models have considered monogyny as an obligate mating strategy, here we explore the potential of monogyny to evolve as a context-specific (conditional) behavior. Using a state-dependent dynamic game model based on the biology of the cannibalistic spider Argiope bruennichi, we confirm that conditional monogyny can evolve under broad conditions, including an even sex ratio. We predict that males should make a terminal investment when mating with large, virgin females, especially if population density is low and the encounter occurs late in the season. We encourage e…
Biological Stability of Organic Fraction of Municipal Solid Wastes During Composting Processes
2018
The article shows results of monitoring of a Sicilian composting plant (southern Italy). In particular, the biological stability of the organic fraction of municipal solid wastes has been monitored. Two experimental periods have been carried out: (1) plant start-up and (2) first operation period. The biological stability has been evaluated throughout the dynamic respiration index (DRI). This index was determined at different stages of process, for each phase. To our knowledge, no work has been previously published on the monitoring of composting plants in southern Italy. This work has the originality of using the DRI measured data for improving operation of a full-scale composting plant, ra…
3D nanoscale ordered architectures in thin films for organic electronics
2011
Order in molecular thin films is of fundamental importance to gain and exploit a series of properties in nanotechnology. In this contest, engineering 2D supramolecular and molecular superstructures is of particular interest. They offer great possibilities for several applications whose achievement also allows for new theoretical approaches and nanoscale laws [1]. A natural extension of 2D nanopatterning concerns the attainment of a 3D nanoscale control in molecular films [2]. This question is complex to challenge and it is of ultimate importance in emerging fields like organic and hybrid photovoltaics, organic thin film transistors and sensors as well as plastic electronics. For example, th…