Nonuniform and Unsteady Solute Transport in Furrow Irrigation. I: Model Development

A cross-section-averaged advection-dispersion equation (ADE) model was developed to simulate the transport of fertilizer in furrow irrigation. The advection and dispersion processes were solved separately at each time step by implementing a method of characteristics with cubic-spline interpolation and a time-weighted finite-difference scheme, respectively. The upstream boundary condition was a prescribed concentration. Downstream, a zero-flux boundary condition during advance and a concentration gradient following completion of advance were prescribed. Local pseudosteady state was assumed in order to apply Fischer’s longitudinal dispersion equation under nonuniform and unsteady furrow flow conditions. Statistical parameters were used to evaluate the ADE model performance.     

Does information about the source of functional ingredients influence consumer perception of functional milk desserts?

BACKGROUND: The aims of the present study were to study the influence of information about the source of two functional ingredients (antioxidants and fibre) on consumer perception of functional milk dessert concepts and to evaluate whether this influence depends on consumer attitudes towards health and hedonic characteristics of foods. RESULTS: Scores for expected liking decreased when information about the source of fibre or antioxidants was incorporated, which could be explained considering that when consumers knew the source of the functional ingredient they imagine the flavour of the source in the milk concept. This decrease in expected liking led to a decrease in consumer willingness to purchase, showing the importance of hedonic expectations on the acceptance of functional foods. Consumers with different attitudes towards health and hedonic characteristics of foods reacted differently towards information about the source of functional ingredients. CONCLUSION: Providing information about the source of functional ingredients would not be recommended as it might create negative taste expectations to consumers and a concomitant decrease in their willingness to purchase. These show that consumers would not compromise on the taste of milk desserts for health. Thus, the development of functional foods that taste worse than conventional ones may be a risky option. Copyright © 2008 Society of Chemical Industry     

Development of an expert system for preliminary risk assessment of existing concrete dams

The paper presents an expert system to assist in the field inspection of existing concrete dams within the context of a preliminary risk assessment. The paper describes the engineering knowledge and reasoning required to conduct a deterministic field evaluation of the structural stability of the dam. The symptoms and failure modes identified by the expert system along with the required knowledge and procedures are organized in a structured knowledge tree. The instantiation of the frames and firing of the rules for each consultation traces part of the inference tree contained in the structured knowledge tree. Interaction between nearly decomposable problems are executed with metaknowledge procedures, shared rule groups, and active values. Examples are provided.     

Application of the Colorado River Simulation System Model to Evaluate Water Shortage Conditions in the Central Arizona Project

Central Arizona Project (CAP) is currently enhancing its water resources modeling capabilities to improve water resources management and planning activities and to better understand the inherent complexities of the Colorado River Basin system. CAP modeling activities in the Colorado River Basin extensively utilize the Colorado River Simulation System (CRSS) model. CRSS is a sophisticated object-oriented surface water model developed under the RiverWare modeling environment and maintained by the United States Bureau of Reclamation (USBR). CRSS incorporates important aspects of the Colorado River Basin: main stem, reservoirs along the river, water inflows to the river, and points of water deliveries. By using the object-oriented and rule-based capabilities of RiverWare, CRSS has embedded the rules of the Law of the River. These set of rules guide the operation and management of the Colorado River Basin’s surface water supply. This analysis executes CRSS short term simulations to evaluate the vulnerability of water deliveries to CAP from the Colorado River under different extreme hydrological and policy conditions. In the future, this type of analysis will provide key input for other CAP models, aimed to improve a quantitative understanding of the impacts of different uncertain and complex scenarios: drought conditions, future user demand behavior, reservoir operation, and optimize water recovery as a part of Arizona Water Bank Authority (AWBA), among others.     

Non reciprocal single mode conversion in multilayer magnetooptical waveguides

Multilayer structures are of great interest in the fabrication of single mode devices for Integrated Optics. this work it is shown that a multilayer structure allows not only single-mode behaviour but it enhaces the non-reci procity of the quide.     

Dysprosium‐Doped (Ba,Sr)TiO3 Thin Films on Nickel Foilsfor Capacitor Applications

The substitution in (Ba_0.70Sr_0.30)TiO₃ thin films by the rare‐earth element dysprosium prepared at 1000°C by chemical solution deposition on nickel foils was investigated. The relatively large thermal budget applied (via annealing temperature) is shown to enhance the solubility of the Dy³⁺doping ion into the crystal lattice of the perovskite films. Preference for B‐site occupancy of this amphoteric cation was further promoted by the addition of BaO excess (1 mol%), which results in slightly larger grains in the films as observed by scanning electron microscopy. Despite this Ba‐rich composition, the presence of secondary phases in the thin films was not detected by X‐ray diffraction. Transmission electron microscopy revealed no evidence for local segregation of Dy at grain boundaries, neither the formation of NiO at the interface between the film and the metal foil was observed. The substitution of Ti⁴⁺ by Dy³⁺ leads to the formation of strong electron acceptors in the system, which balance the number of ionized oxygen vacancies arisen from the reductive crystallization atmosphere used during processing. As a consequence, the dielectric loss (tan σ) and leakage conduction measured in the resulting thin‐film capacitors were significantly reduced with respect to nominally undoped samples. The improvement of this capacitor feature, combined with the relatively high permittivities obtained in the films (490–530), shows the effectiveness of dysprosium doping within a thin‐film fabrication method for potential application into the multilayer ceramic capacitor technology.     

Motives for strategic alliances in cultural and creative industries

Cultural and creative industries are gaining importance in Western economies. In these industries, as in several other business sectors, micro‐firms, i.e., firms that employ fewer than ten employees, are the predominant firm type. As these industries have become an integral part of most economies, the literature has started to explore the strategic behavior of cultural and creative micro‐firms. Although micro‐firms are characterized by certain specificities that can affect how likely they are to engage in external relationships, there is a dearth of knowledge concerning collaboration through strategic alliances in this specific context. Seeking to advance the understanding of partnerships between micro‐firms in cultural and creative industries, the purpose of this article is to reveal the specific motives for engaging in strategic alliances in this context. In doing so, we focus on six case studies of strategic alliances between micro‐firms in cultural and creative industries in France. Our results show that strategic alliances involving creative micro‐firms seek the reduction of overspecialization, target a high degree of quality of life and pleasure at work, and are envisaged only if there is trust and mutual support among the partners. Moreover, opportunism and necessity motivations guide the creative micro‐firms' decision to enter strategic alliances.     

Formation of a long-lived P+BA- state in plant pheophytin-exchanged reaction centers of Rhodobacter sphaeroides R26 at low temperature

Femtosecond transient absorption spectroscopy in the range of 500-1040 nm was used to study electron transfer at 5 K in reaction centers of Rhodobacter sphaeroides R26 in which the bacteriopheophytins (BPhe) were replaced by plant pheophytin a (Phe). Primary charge separation took place with a time constant of 1.6 ps, similar to that found in native RCs. Spectral changes around 1020 nm indicated the formation of reduced bacteriochlorophyll (BChl) with the same time constant, and its subsequent decay in 620 ps. This observation identifies the accessory BChl as the primary electron acceptor. No evidence was found for electron transfer to Phe, indicating that electron transfer from BA- occurs directly to the quinone (QA) through superexchange. The results are explained by a model in which the free energy level of P+Phe- lies above that of P+BA-, which itself is below P*. Assuming that the pigment exchange does not affect the energy levels of P* and P+BA-, our results strongly support a two-step model for primary electron transfer in the native bacterial RC, with no, or very little, admixture of superexchange.