A Derivative-Free Hybrid Optimization Model for Short-Term Operation of a Multi-Objective Reservoir System Under Uncertainty

Short-term operation of a multi-objective reservoir system under inflow uncertainty has been receiving increasing attention, however, major challenges for the optimization of this system still remain due to the multiple and often conflicting objectives, highly nonlinear constraints and uncertain parameters in which derivative information may not be directly available. Population-based optimization methods do not rely on derivatives while generally have a slow convergence. This study presents a hybrid optimization model for short-term operation of multi-objective reservoirs under uncertainty that is derivative free and has a relatively fast convergence. The model incorporates a local improvement method called Mesh Adaptive Direct Search (MADS) into a population-based method NSGA-II and has no requirement for differentiability, convexity and continuity of the optimization problem. The operation of a multi-objective and multi-reservoir system on the Columbia River under inflow uncertainty is used as a case study. Overall, the hybrid model outperforms optimization models based on either the NSGA-II only or the MADS only. The model is intended for conditions where derivative information of the optimization problem is unavailable, which could have a wide array of applications in water resources systems.     

三重播放时代需要的基础设施DSP

语音/数据/媒体网络的兴起要求高性能与高速IO完美结合.本文将探讨如何选择可满足上述要求的DSP.提供低成本解决方案     

Aldol condensation in gaseous phase by zeolite catalysts

Vapour-phase reactions of, in situ, prepared formaldehyde with methyl propionate were studied using X, Y and ZSM-5 zeolite catalysts. Base properties of these zeolites were enhanced by KOH or NaN₃ treatment. The niobium and molybdenum ZSM-5 zeolite supported oxides were also tested for their catalytic activity. The results are discussed in terms of an ability of zeolite catalysts to synthesize methyl methacrylate.     

Characterization of and male adaptation to pheromone of femaleTrichostrongylus colubriformis (Nematoda)

Males of the ruminant nematodeTrichostrongylus colubriformis were significantly attracted to an incubate from their females during in vitro assay. Exposure of males to sera from uninfected and infected animals or selected neurotransmitters had no effect on their subsequent responsiveness to the female's pheromone. In contrast, exposure to 1500 female-hours of pheromone decreased male responsiveness after moderate rinsing prior to bioassay. Rinsing of the males with larger volumes of Tyrode's solution prior to in vitro assay increased their subsequent response to the female's pheromone. High-performance liquid chromatography yielded a presumptive pheromone peak with a fivefold increase in biological activity. This peak was soluble in alcohols and tetrahydrofuran, based on elution from reverse-phase Sep-Pak cartridges. Stability of the peak was increased by EDTA or ascorbic acid (10 mM). Storage for six weeks in ascorbic acid at 4 °C allowed recovery of 47.3% of the original material.Mention of a trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable.     

The polymerization of acenaphthylene by sulphuric acid in methylenedichloride

Summary Acenaphthylene was polymerized in methylenedichloride at 273, 291 and 308 K by sulphuric acid. The initiation step takes place by addition of the proton of sulphuric acid to the monomer. The propagation step is through ion-pairs, and the propagation constants are first-order with respect to the monomer and initiator(k_p = 0.22 M^–1. s^–1(273K), k_p=0.88 M^–1. s^–1(291K), k_p = 2.81 M^–1. s^–1 (308K)). There is not appreciable loss of active centres, being this confirmed by experiments carried out with succesive additions of monomer. The molecular weights obtained confirm the importance of processes to monomer in this polymerization.     

Solid state magnetic resonance spectra of Illinois No. 6 coal and some reductive alkylation products

Illinois No. 6 coal and its reductive methylation and butylation products have been studied by magnetic resonance techniques. Conventional CP-MAS¹³Cn.m.r. spectroscopy indicates that 62% of the carbon atoms in the coal are aromatic and that about 6% of the carbon atoms are carbonyl. Esters are more abundant than carboxylic acids. The resonances of methoxy groups and other novel etheric carbon atoms are apparent in the high field region. Dipolar dephasing experiments suggest that methyl carbon atoms constitute no more than 16% of the carbon, methylene and methine carbon atoms about 14% and quaternary aliphatic carbon atoms about 2%. The dipolar dephasing experiments in conjunction with previous work also permit estimates of the hydrogen atom distribution. The THF-insoluble products obtained in the reductive alkylation reactions with¹³C-enriched alkylating agents contain paramagnetic and ferromagnetic substances that adversely influence the solid state n.m.r. spectra. However, good ¹³C n.m.r. spectra were obtained after these substances were extracted with aqueous hydrochloric acid. The O:C alkylation ratios are 1.2 and 1.0 for methylation and butylation, respectively. Dipolar dephasing experiments establish that the decay constants of functional groups in the whole coal and of C- and O-methyl-¹³C and C- and O-butyl-1 -¹³C nuclei in the labelled coal molecules are very similar to those of reference compounds. These findings suggest that the decay constants measured for the ¹³C nuclei in coals and coal-derived solids provide reliable information about their degree of substitution.     

Ruthenium tetroxide catalysed oxidation of Illinois No. 6 coal: The formation of volatile monocarboxylic acids

Ruthenium tetroxide selectively oxidizes activated aromatic compounds under mild conditions and has been used for the catalytic oxidation of several different coals. The quantities of the volatile monocarboxylic acids with 2–6 carbon atoms have been determined by an isotope dilution technique. The amount of ethanoic acid ranges from 1 to 3mol/100C and the quantities of propanoic acid, and butanoic acid exceed 0.1 mol/100C. Methylpropanoic, pentanoic, 2-methylbutanoic, 3-methylbutanoicand hexanoic acid are formed in lesser amounts. The outcome of the experiment depends upon whether or not the coal has been extracted prior to oxidation. The results for Illinois No. 6 coal expressed in moles of ethanoic acid produced/l00C illustrate this feature: raw whole coal, 1.9; coal extracted by the method of Hayatsu and co-workers, 1.0. Dehydrogenation with benzoquinone prior to oxidation increases the yield of ethanoic acid to $\text{sol1.5mol}\text{100C.}$ The amounts of ethanoic acid obtained from the other extracted coals are 1.0 for Texas lignite, 1.2 for Rawhide subbituminous, 3.4 for Pittsburgh No. 8, 3.3 for a higher ranking bituminous coal (PSOC 726) and 0.7 for an anthracite (PSOC872). The results obtained in this study are compared with related information concerning the distribution of alkyl groups within coal by other methods.     

What happens when mother is away: A comparison of mothers and substitute caregivers.

Compared maternal and substitute care in 2 groups of 5–6 mo old infants. Significant differences favoring maternal care were found in expression of positive affect, social play, social mediation of inanimate objects, and variety of both social and inanimate stimulation. Duration of regular contact between the infant and substitute caregiver was positively related to the substitute's caregiving behavior. Mother-reared infants engaged in significantly more focused exploration at home but were comparable to the substitute-care group on 16 other measures of infant functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Process‐product studies on starch acetylation reactions in pressurised carbon dioxide

An in‐depth study on the effect of process conditions (pressure, temperature and type of catalyst) on the acetylation of starch with acetic anhydride in pressurised carbon dioxide is described. A total of 22 experiments were performed and the experimental data were analysed using non‐linear multivariable regression. The highest degree of substitution (DS) value (0.46) was obtained using K₂CO₃ as the catalyst at 90°C, 15 MPa pressure, and a catalyst to starch ratio of 0.5 mol/mol anhydroglucose units (AGUs). Important product properties of the acetylated starch prepared in CO₂ like viscosity in water and relevant thermal properties were determined and compared with typical products prepared in an aqueous system.