458 research outputs found
Aging, Gender and Neighbourhood Determinants of Distance Traveled: A Multilevel Analysis in the Hamilton CMA
No full textThe objective of this study is to investigate the determinants of mean trip distance traveled by different mode types. The study uses data from the Hamilton CMA in Canada, and multilevel models to investigate demographic aging factors, gender differentials, and neighbourhood attributes on distance traveled. The results of the study validate previous findings regarding the decline in distance traveled as age advances. In addition, it is found that: 1) While this effect of age is present for all modes analyzed (car-driving, car-passenger, and bus) it is considerably more marked for car-driving; 2) There are significant gender effects compounded by the interrelated factors of employment constraints, household dynamics, and greater reliance on travel modes other than car driving; and 3) Neighbourhoods with high commercial and residential mix showed a negative relation with distance traveled only in the case of car-driver.distance traveled, aging, elderly, gender, neighbourhood influence, multilevel analysis
Hierarchical and Anisotropic Nanostructured Catalysts
No full textAnisotropic nanoparticles (NPs) exhibit unique and superior physicochemical properties to isotropic particles. This chapter illustrates the breadth of hierarchically porous and anisotropic NPs and approaches to their synthesis and catalytic applications, focusing on the impact of NP morphology, porosity, and chemical functionalization on activity, selectivity, and stability. Top-down approaches create NPs by the removal of extraneous material from a bulk sample using reactive ion or chemical etching to produce highly uniform NPs. In the bottom-up approach, molecular components arrange into more complex assemblies atom by atom, molecule by molecule, or cluster by cluster. Catalytic Janus nanostructures include bimetallics, metals and oxides, and inorganic carbons and oxides. The coupling of two or more distinct pore networks, typically micro-and mesopores or meso-and macropores, yields material possessing hierarchical porosity. Such architectures have shown benefits in a variety of catalytic transformations, often attributed to enhanced internal mass transport and/or superior dispersion of active sites.No Full Tex
Solving Satisfiability in Fuzzy Logics by Mixing CMA-ES (abstract)
No full textSatisfiability in propositional logic is well researched and many approaches to checking and solving exist. In infinite-valued or fuzzy logics, however, there have only recently been attempts at developing methods for solving satisfiability. In this paper, we analyse the function landscape of different problem classes, focussing our analysis on plateaus. Based on this study, we develop Mixing CMA-ES (M-CMAES), an extension to CMA-ES that is well suited to solving problems with many large plateaus. We empirically show the relation between certain function landscape properties and M-CMA-ES performance
Impact of ceria support morphology on Au single‐atom catalysts for benzyl alcohol selective oxidation
No full textAlcohol oxidations are a key industrial chemical transformation, with aldehydes and ketones finding use in an array of applications. Nobel metals are known for their activity towards this chemoselective transformation, however, sustainable catalyst synthesis requires optimal utilisation of these scarce elements. Here, we report Au catalytic systems based on the deposition of isolated Au sites on different morphologies of ceria in which different surface facets of the support are exposed. Through tailoring the support morphology and from extensive catalyst characterisation, it is shown that the exposed facet is critical for controlling the formation (or not) of isolated Au sites. Both the 110 and 111 facets are capable of this feat, yielding single-atom sites for rod, octahedron, and polyhedron morphologies. In contrast, the 100 facet is not, resulting in Au nanoparticles on cubic ceria. This dictation over Au species is critical to benzyl alcohol oxidation capacity at mild conditions and in the absence of a soluble base, with only single-atom catalyst (SAC) systems demonstrating activity. Furthermore, the exposed surface facet also governs the degree of surface oxygen vacancies, which is critical to catalyst activity due to their control over substrate adsorption strength, as revealed through T1/T2 NMR relaxation measurements
Multi-objective optimization of permanent magnet motors using deep learning and CMA-ES
No full textThis paper proposes a multi-objective optimization method for permanent magnet motors using a fast optimization algorithm, Covariance Matrix Adaptation Evolution Strategy (CMA-ES), and deep learning. Multi-objective optimization with topology optimization is effective in the design of permanent magnet motors. Although CMA-ES needs fewer population size than genetic algorithm for single objective problems, this is not evident for multi-objective problems. For this reason, the proposed method generates training data by solving the single-objective optimization multiple times using CMA-ES, and constructs a deep neural network (NN) based on the data to predict performance from motor images at high speed. The deep NN is then used for fast solution of multi-objective optimization problems. Numerical examples demonstrate the effectiveness of the proposed method
The Impact of Immigration on the Labour Market Outcomes of Native-born Canadians
No full textAlthough immigration has become a major growth factor for Canadian labour force, there is little economic research on the effect of immigration on native-born Canadians' labour market performance. This paper examines the relationship between changes in the share of immigrants by sub-labour markets (categorized by skill types and geographic areas) and changes in native wage growth by a two-stage regression analysis, using 1991, 1996 and 2001 Canadian Census microdata. After accounting for biases due to native mobility, endogenous location of immigrants and labour demand shifts, the estimated effects of immigration are consistently insignificant or significantly positive. The results are robust over various specifications of sub-labour markets at city, provincial and national levels, suggesting no evidence for a negative impact on native wage growth rate from the large immigrant influx during the 1990s.immigration, labour supply, labour mobility, wage
Practical Product Development Challenges
No full textDespite the many product development techniques available today, manufacturers under pressure to reduce time to market while keeping up with stricter regulatory demands are struggling more than ever with their product development processes. Here, I list a selection of problems and challenges frequently encountered in my consulting practice and checked with literature, as well as practical recommendations for improvement. While in specific situations some project management techniques prove better suited than others, overall product development success seems more dependent on the organization's willingness and ability to learn and adapt rather than on the specific technique chosen.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentatio
Intermediates during the Nucleation of Platinum Nanoparticles by a Reaction with Ethylene Glycol: Operando X-ray Absorption Spectroscopy Studies with a Microfluidic Cell
No full textUsing operando X-ray absorption spectroscopy in a continuous-flow microfluidic cell, we have investigated the nucleation of platinum nanoparticles from aqueous hexachloroplatinate solution in the presence of the reducing agent ethylene glycol. By adjusting flow rates in the microfluidic channel, we resolved the temporal evolution of the reaction system in the first few seconds, generating the time profiles for speciation, ligand exchange, and reduction of Pt. Detailed analysis of the X-ray absorption near-edge structure and extended X-ray absorption fine structure spectra with multivariate data analysis shows that at least two reaction intermediates are involved in the transformation of the precursor H₂PtCl₆ to metallic platinum nanoparticles, including the formation of clusters with Pt–Pt bonding before complete reduction to Pt nanoparticles
Agutagawa
No full textMedium: Woodcut.Print Image Size: 14 x 11 inches.Print Edition: no edition.Alternate Medium: Woodcut.Ink(s): black.Support: laid mulberry paper.A bust-length portrait of Ryunosuke Akutagawa - whose works include the short stories In a Grove and Rashoman - holding a book and writing brush. An alternate portrait of the author [CMA 2001.034.033] was completed the same year
Synthesis and catalytic advantage of a hierarchical ordered macroporous KIT-6 silica
No full textOrdered mesoporous silicas are important technological materials in catalysis, sorption and separation science, however new architectures are desired to improve in-pore accessibility. Here we report the first synthesis of an ordered macroporous KIT-6, obtained by optimizing the ratios of Pluronic P123: sodium dodecyl sulfate cosurfactants, and a 400 nm polystyrene nanosphere macropore template. The macroporous KIT-6 possesses 370 nm macropores in a face-centered cubic arrangement, surrounded by a silica framework comprised of cubic Ia3¯d three-dimensional, intertwined 5 nm mesopore channels. Propylsulfonic acid (PrSO 3H) functionalization affords a macroporous KIT-6 solid acid catalyst whose hierarchical pore network permits rapid diffusion and esterification of fatty acids, conferring a five-fold enhancement for palmitic acid esterification compared with a conventional mesoporous PrSO 3H/KIT-6, and 33% rate enhancement vs. an ordered macroporous PrSO 3H/SBA-15.</p
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