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Selected AbstractsMethodology for preliminary seismic design of extended pile-shafts for bridge structuresEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 14 2006S. T. Song Abstract Seismic design of extended pile-shafts requires a careful consideration of the influence of the surrounding soil on the overall response of the soil,pile system. In this paper, a procedure that incorporates soil properties into the process is developed for preliminary seismic design of extended pile-shafts. The method follows the well-accepted approach of using a force reduction factor to determine the lateral strength of the structure. The procedure involves an iterative process to arrive at the required amount of longitudinal reinforcement. Other outcomes of the procedure include the appropriate lateral stiffness and strength, as well as an estimation of the local curvature demand and ultimate drift ratio that can be used to ensure a satisfactory lateral response. The design procedure is capable of providing reliable results for a practical range of structural and soil properties. The versatility of the procedure is illustrated using two numerical examples of extended pile-shafts constructed in different soil sites. Copyright © 2006 John Wiley & Sons, Ltd. [source] Functional intravascular volume deficit in patients before surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010M. BUNDGAARD-NIELSEN Background: Stroke volume (SV) maximization with a colloid infusion, referred to as individualized goal-directed therapy, improves outcome in high-risk surgery. The fraction of patients who need intravascular volume to establish a maximal SV has, however, not been evaluated, and there are only limited data on the volume required to establish a maximal SV before the start of surgery. Therefore, we estimated the occurrence and size of the potential functional intravascular volume deficit in surgical patients. Methods: Patients scheduled for mastectomy (n=20), open radical prostatectomy (n=20), or open major abdominal surgery (n=20) were anaesthetized, and before the start of surgery, a 200 ml colloid fluid challenge was provided and repeated if a ,10% increment in SV estimated by oesophageal Doppler was established. The volume needed for SV maximization defined the intravascular volume deficit. Results: Forty-two (70%) of the patients needed volume to establish a maximal SV. For the patients needing volume, the required amount was median 200 ml (range 200,600 ml), with no significant difference between the three groups of patients. The required volume was ,400 ml in nine patients (15%). Conclusion: The majority of anaesthetized patients present with a functional intravascular volume deficit before surgery. Although the deficit in general was minor, a fraction of patients presented with a deficit that may be of clinical relevance, emphasizing the importance of the individual approach of goal-directed fluid therapy. [source] Effects of Solids Loading, pH, and Polyelectrolyte Addition on the Stabilization of Concentrated Aqueous BaTiO3 SuspensionsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2000Jau-Ho Jean Colloidal stability of concentrated aqueous BaTiO3 suspensions with ammonium salts of poly(acrylic acid) (PAA-NH4) and poly(methacrylic acid) (PMAA-NH4) as a function of pH and solids loading is investigated. For suspensions with solids loading less than 40 vol%, the required polyelectrolyte concentration to stabilize aqueous BaTiO3 suspensions decreases with increasing pH, but remains relatively unchanged with increasing solids loading. As the solids loading continuously increases (e.g., >50 vol%), the required amount of polyelectrolyte increases, but exhibits a minimum at pH , 9.2. The critical amount of polyelectrolyte needed to achieve colloidal stability of aqueous BaTiO3 suspensions as a function of pH and solids loading is summarized in a three-dimensional stability map. [source] On the complexity of resilient network designNETWORKS: AN INTERNATIONAL JOURNAL, Issue 2 2010Artur Tomaszewski Abstract In this article we prove ,,,,-hardness of two well-known optimization problems related to the design of multicommodity flow networks with two different methods for providing network resiliency against failures: path diversity and flow restoration. Path diversity is a static mechanism that consists of using, for each demand, a number of paths and oversizing the flows assigned to these paths so that for any failure the total surviving flow is not less than the volume of the demand. By contrast, flow restoration is a dynamic mechanism that consists of reassigning the failed flows to backup paths when a failure occurs. Both mechanisms are of practical interest because although flow restoration is in general superior to path diversity in terms of the required amount of resource capacity, it might be too complicated to implement. By providing an appropriate reduction from the fractional graph coloring problem, we show that both problems are ,,,,-hard in the general case of failure scenarios that admit simultaneous failures of multiple links. Finally, we discuss how to efficiently solve the two problems using path generation techniques. © 2009 Wiley Periodicals, Inc. NETWORKS, 2010 [source] Alternate oils in fish feedsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 3 2007Jana Pickova Abstract Nearly half of the fish consumed as food worldwide are raised on fish farms rather than caught in the wild, as shown by FAO statistics. The increasing aquaculture of predatory carnivorous fish demands new sources of feed constituents, particularly oils at the moment. Common terrestrial plant oils contain only traces of the long-chain polyunsaturated fatty acids. In connection with fish feed, especially the lack of n -3 "marine fatty acids" is obvious. Recommendations on the required amounts of the fatty acids DHA (22:6n -3) and EPA (20:5n -3) exist from 1994. When plant oil-based diets are fed during the growing phase and replaced by a fish oil-based diet during a period prior to slaughter, most of the beneficial lipid composition of fish in terms of human dietary recommendations is restored. Little attention has been focused on the fish welfare in connection to substitution of dietary oil sources, and studies are still scarce. New fish diets will rely heavily on the use of alternate ingredients such as plant oils also for carnivorous cold-temperate water fish species. In the future, an addition of synthetic or GMO-produced "marine" fatty acids is a possible scenario. The aim of this review is to highlight some plant oils used in fish feeds, with special emphasis on compounds other than fatty acids. We also include some results from an ongoing study, where the effect of dietary soy oil on gonad maturation in Atlantic cod (Gadus morhua) is indicated. [source] Resource allocation for statistical quality of service provision in buffered crossbar switches,INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2008Qiang Duan Abstract The buffered crossbar switch is a promising switching architecture that plays a crucial role for providing quality of service (QoS) in computer networks. Sufficient amount of resources,bandwidth and buffer space,must be allocated in buffered crossbar switches for QoS provision. Resource allocation based on deterministic QoS objectives might be too conservative in practical network operations. To improve resource utilization in buffered crossbar switches, we study the problem of resource allocation for statistical QoS provision in this paper. First, we develop a model and techniques for analyzing the probabilistic delay performance of buffered crossbar switches, which is described by the delay upper bound with a prescribed violation probability. Then, we determine the required amounts of bandwidth and buffer space to achieve the probabilistic delay objectives for different traffic classes in buffered crossbar switches. In our analysis, we apply the effective arrival envelope to specify traffic load in a statistical manner and characterize switch service capacity by using the service curve technique. Instead of just focusing on one specific type of scheduler, the model and techniques developed in this paper are very flexible and can be used for analyzing buffered crossbar switches with a wide variety of scheduling algorithms. Copyright © 2007 John Wiley & Sons, Ltd. [source] A Microcapillary System for Simultaneous, Parallel Microwave-Assisted SynthesisCHEMISTRY - A EUROPEAN JOURNAL, Issue 24 2005Eamon Comer Abstract A continuous flow, microwave-assisted, parallel-capillary microreactor has been developed. Libraries of drug candidates were prepared on the milligram scale with this reactor by injecting plugs of reagents from separate syringes into common reaction capillaries, thereby producing discrete compounds in excellent yield and purity. Microwave irradiation provides the necessary energy that existing room-temperature microreactor technology lacks for higher activation barrier transformations, producing the required amounts of desired compounds in minutes or less. [source] | ||||||||||