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Best Case (best + case)
Selected AbstractsHard-to-Solve Bimatrix GamesECONOMETRICA, Issue 2 2006Rahul Savani The Lemke,Howson algorithm is the classical method for finding one Nash equilibrium of a bimatrix game. This paper presents a class of square bimatrix games for which this algorithm takes, even in the best case, an exponential number of steps in the dimension d of the game. Using polytope theory, the games are constructed using pairs of dual cyclic polytopes with 2d suitably labeled facets in d -space. The construction is extended to nonsquare games where, in addition to exponentially long Lemke,Howson computations, finding an equilibrium by support enumeration takes on average exponential time. [source] Preparation-Condition Dependence of Hybrid SiO2 -Coated CdTe Nanocrystals with Intense and Tunable PhotoluminescenceADVANCED FUNCTIONAL MATERIALS, Issue 8 2010Ping Yang Abstract When aqueously prepared CdTe nanocrystals (NCs) are coated with a SiO2 shell containing Cd ions and a sulfur source, they show a drastic increase in photoluminescence (PL) efficiency with a significant red shift and spectral narrowing after reflux. This is ascribed to the creation of a hybrid structure characterized by the formation of CdS-like clusters in the vicinity of the NCs in the SiO2 shell. Since these clusters are close to the NCs, their effective size increases to reduce the quantum size effect. The dependences of the PL properties on the preparation conditions are systematically investigated. The PL efficiency increases from 28% to 80% in the best case with a red shift of 80,nm. The PL behaviors differ from those of normal CdTe NCs and include less temperature quenching and longer PL lifetime. The SiO2 coating enables bioconjugation with IgG without deterioration of PL efficiency, making hybrid NCs amenable for bioapplication. [source] Efficiencies of NaOH production methods in a Kraft pulp millINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2009Tobias Richards Abstract There are several processes in a Kraft pulp mill where there is a need for sodium hydroxide, e.g. in the digester and the bleaching plant. The objective of this study is to perform a preliminary evaluation, intended to select the best alternative for producing sodium hydroxide on a Kraft pulp mill site. The first step of the evaluation consists of screening available processes for producing sodium hydroxide needed in the mill. The first step of the evaluation shows that the two best options for increasing the production of sodium hydroxide for internal use in a mill are the conventional lime cycle process or direct causticization with titanates. The second step of the evaluation compares the lime cycle and the titanate process using first and second law analyses to determine the energy requirement and the exergy efficiencies of both processes. Such analyses show a higher energy requirement and a lower exergy efficiency in the titanate process than in the lime cycle process without any heat integration. However, the titanate process shows better performance in terms of energy requirement and exergy efficiency than the lime cycle, if heat is integrated into both processes. The titanate process requires, in the best case, only 80% of the energy required for a fully heat-integrated lime cycle process. Copyright © 2009 John Wiley & Sons, Ltd. [source] The acceptability to stakeholders of mandatory nutritional labelling in France and the UK , findings from the PorGrow projectJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 1 2010M. Holdsworth Abstract Background:, Implementing a European Union (EU)-wide mandatory nutrition labelling scheme has been advocated as part a multi-pronged strategy to tackle obesity. The type of scheme needs to be acceptable to all key stakeholders. This study explored stakeholders' viewpoints of labelling in two contrasting food cultures (France and the UK) to see whether attitudes were influenced by sectoral interests and/or national context. Methods:, Using Multi Criteria Mapping, a decision analysis tool that assesses stakeholder viewpoints, quantitative and qualitative data were gathered during tape-recorded interviews. In France and the UK, 21 comparable stakeholders appraised nutritional labelling with criteria of their own choosing (i.e. feasibility, societal benefits, social acceptability, efficacy in addressing obesity, additional health benefits) and three criteria relating to cost (to industry; public sector; individuals). When scoring, interviewees provided both optimistic (best case) and pessimistic (worst case) judgements. Results:, Overall, mandatory nutritional labelling was appraised least favourably in France. Labelling performed worse under optimistic (best case) scenarios in France, for five out of eight sets of criteria. French stakeholders viewed labelling as expensive, having fewer benefits to society and as being marginally less effective than UK stakeholders did. However, French interviewees thought implementing labelling was feasible and would provide additional health benefits. British and French stakeholders made similar quantitative judgements on how socially acceptable mandatory labelling would be. Conclusions:, There is agreement between some stakeholder groups in the two different countries, especially food chain operators. However, cultural differences emerged that could influence the impact of an EU-wide mandatory labelling scheme in both countries. [source] A backoff strategy for model-based experiment design under parametric uncertaintyAICHE JOURNAL, Issue 8 2010Federico Galvanin Abstract Model-based experiment design techniques are an effective tool for the rapid development and assessment of dynamic deterministic models, yielding the most informative process data to be used for the estimation of the process model parameters. A particular advantage of the model-based approach is that it permits the definition of a set of constraints on the experiment design variables and on the predicted responses. However, uncertainty in the model parameters can lead the constrained design procedure to predict experiments that turn out to be, in practice, suboptimal, thus decreasing the effectiveness of the experiment design session. Additionally, in the presence of parametric mismatch, the feasibility constraints may well turn out to be violated when that optimally designed experiment is performed, leading in the best case to less informative data sets or, in the worst case, to an infeasible or unsafe experiment. In this article, a general methodology is proposed to formulate and solve the experiment design problem by explicitly taking into account the presence of parametric uncertainty, so as to ensure both feasibility and optimality of the planned experiment. A prediction of the system responses for the given parameter distribution is used to evaluate and update suitable backoffs from the nominal constraints, which are used in the design session to keep the system within a feasible region with specified probability. This approach is particularly useful when designing optimal experiments starting from limited preliminary knowledge of the parameter set, with great improvement in terms of design efficiency and flexibility of the overall iterative model development scheme. The effectiveness of the proposed methodology is demonstrated and discussed by simulation through two illustrative case studies concerning the parameter identification of physiological models related to diabetes and cancer care. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Monitoring ultrathin film photopolymerization of tetra-alkylepoxyporphyrin by UV-Vis spectroscopyJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2009Kalle Lintinen Abstract Cationic photopolymerization is a convenient in situ polymerization method for organic thin film preparation. In this work, the polymerization mechanisms is applied for highly viscous cross-linking monomers, using tetra-alkylepoxyporphyrin (TAEP) as a case study. By comparing the UV-Vis spectra of the polymerized sample before and after the unreacted monomers have been dissolved, it is possible to estimate the polymerization yield. An IR spectrum of a reference thick film confirms full polymerization. Scanning fluorescence lifetime microscopy and AFM show the uniformity of the polymer. It was shown that photopolymerization is highly dependent on the substrate nature and requires at best case a 10 min illumination at 90 °C. Thermal polymerization of the same sample requires 10 min heating at 150 °C in dark. It was also shown that TAEP works as a self-sensitizer for cationic photopolymerization. The proposed method is a mild and versatile technique for in situ preparation of thin polymeric films directly from chromophore monomers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6095,6103, 2009 [source] Actively Q-switched, diode pumped thulium laserLASER PHYSICS LETTERS, Issue 12 2007J.K. Jabczynski Abstract 6 W of output power and near 50% slope efficiency with respect to absorbed pump power was demonstrated in freerunning mode for a short, 40-mm long resonator. The uncoated, with 3.5% dopant of thulium YLF rod of.3× 8 mm size wrapped with indium foil was mounted in copper heat-sink maintaining 293 K temperature of coolant water and inserted in a short, 40-mm long resonator. For pumping the fiber coupled (0.4 mm core diameter) laser diode bar at 792-nm wavelength was deployed. The fused silica acousto-optic modulator with above 80% diffraction efficiency for 25-W power of RF was taken as the Q-switch for such a laser. In the best case of Qswitching mode up to 2-mJ output energy with 20-ns pulse duration corresponding to 100-kW peak power was demonstrated for rep. rate of a few Hz. Emission wavelength was around 1904 nm for both free-running and Q-switching regimes. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Shaping and timing gradient pulses to reduce MRI acoustic noise,MAGNETIC RESONANCE IN MEDICINE, Issue 2 2010Marcel Segbers MSc Abstract A method to reduce the acoustic noise generated by gradient systems in MRI has been recently proposed; such a method is based on the linear response theory. Since the physical cause of MRI acoustic noise is the time derivative of the gradient current, a common trapezoid current shape produces an acoustic gradient coil response mainly during the rising and falling edge. In the falling edge, the coil acoustic response presents a 180° phase difference compared to the rising edge. Therefore, by varying the width of the trapezoid and keeping the ramps constant, it is possible to suppress one selected frequency and its higher harmonics. This value is matched to one of the prominent resonance frequencies of the gradient coil system. The idea of cancelling a single frequency is extended to a second frequency, using two successive trapezoid-shaped pulses presented at a selected interval. Overall sound pressure level reduction of 6 and 10 dB is found for the two trapezoid shapes and a single pulse shape, respectively. The acoustically optimized pulse shape proposed is additionally tested in a simulated echo planar imaging readout train, obtaining a sound pressure level reduction of 12 dB for the best case. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc. [source] Improving cold storage of subitaneous eggs of the copepod Acartia tonsa Dana from the Gulf of Mexico (Florida , USA)AQUACULTURE RESEARCH, Issue 5 2007Guillaume Drillet Abstract Developing methods to store copepod eggs is necessary to increase the availability of copepods as a live food for the aquaculture industry and aquarium trade, and also to allow the exchange of copepods between researchers. The present study, evaluated the effect of glucose and two antibiotics (kanamycin sulphate and oxytetracycline HCl) on extending the shelf life of cold-stored subitaneous Acartia tonsa eggs. Also, egg development effects on the survival of the eggs were tested. Glucose did not have any significant effects on the survival of the eggs. However, the addition of antibiotics to the storage vials resulted in an increase of the survival of the eggs. In the best case, the shelf life of the eggs was almost doubled. After 7 days, the kanamycin+glucose treatment led to a hatching success of 86±1% of the hatchable eggs, while the untreated eggs presented a hatching success of 47±6%. However, long exposure to high concentrations of antibiotics was lethal to the copepod eggs. After more than 30 days of exposure to 100 mg L,1 of oxytetracycline, the survival of the eggs was lower than in the untreated samples. After 45 days, oxytetracycline-treated eggs (100 mg L,1) presented a hatching success of 4,5% while the non-stored eggs still had a hatching success of 9%, and the eggs treated with a lower concentration of antibiotics (10 mg L,1) showed a hatching success up to 21,23%. The size of the nauplii in all trials tended to decrease as the period of cold storage at 1°C increased. We consider that the use of antibiotics at the right dosage to be a means to increase the storage capacity of the Gulf of Mexico strain of A. tonsa eggs, which do not show any capacity to be stored for long periods of time, compared with some other strains. In addition eggs that were between 5 and 7 h old survived longer when stored in the cold than eggs, which were freshly spawned or closer to hatching. [source] Using barium ions for heavy-atom derivatization and phasing of xylanase II from Trichoderma longibrachiatumACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2007Natalia Moiseeva This paper describes the use of barium chloride to produce a heavy-atom derivative of xylanase II crystals from Trichoderma longibrachiatum, which was obtained either by cocrystallization or soaking. SAD phasing led to interpretable electron-density maps that allowed unambiguous chain tracing. In the best case, with a data set collected at 9.5,keV, 88% of the residues were built, with 83% of the side chains assigned. The barium ions are found to mainly interact with main-chain carbonyl groups and water molecules. It is suggested that barium ions could also be used as a potential anomalous scatterer in the quick cryosoaking procedure for phasing. [source] 10-year prevalence of contact allergy in the general population in Denmark estimated through the CE-DUR methodCONTACT DERMATITIS, Issue 4 2007Jacob Pontoppidan Thyssen The prevalence of contact allergy in the general population has traditionally been investigated through population-based epidemiological studies. A different approach is the combination of clinical epidemiological (CE) data and the World Health Organization-defined drug utilization research (DUR) method. The CE-DUR method was applied in Denmark to estimate the prevalence of contact allergy in the general population and compare it with the prevalence estimates from the Glostrup allergy studies. Contact allergy prevalence estimates ranging from very liberal (,worst case') to conservative (,best case') assumptions were based on patch test reading data in combination with an estimate of the number of persons eligible for patch testing each year based on sales data of the ,standard series'. The estimated 10-year prevalence of contact allergy ranged between 7.3% and 12.9% for adult Danes older than 18 years. The 10-year prevalence of contact allergy measured by CE-DUR was slightly lower than previous prevalence estimates from the Glostrup allergy studies. This could probably be explained by a decrease in nickel allergy. The CE-DUR approach holds the potential of being an efficient and easy monitoring method of contact allergy prevalence. [source] Expression, purification, crystallization and preliminary X-ray analysis of the native class C ,-lactamase from Enterobacter cloacae 908R and two mutantsACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2001J. Wouters Crystals have been obtained of the Enterobacter cloacae 908R ,-lactamase and two point mutants by the vapour-diffusion method using similar conditions [pH 9.0, polyethylene glycol (Mr = 6000) as precipitant]. The three crystal forms belong to the orthorhombic space group P21212, with roughly the same unit-cell parameters; i.e. for the wild-type crystals a = 46.46, b = 82.96, c = 95.31,Å. In the best cases, the crystals diffract to about 2.1,Å resolution on a rotating-anode X-ray source at room temperature. Co-crystallization experiments of poor substrates with the wild-type protein and the active-site serine mutant (S64C) are planned and should lead to a better understanding of the catalytic mechanism of class C ,-lactamases. [source] | ||||||||||||||||