79 research outputs found
Interview with Jacqueline DeGroot
No full textJacqueline DeGroot, author of Climax and Worth Any Price, discusses how she came to be a writer, her writing process and sources of inspiration, and her experiences with self-publishing
Investigation of the Synthesis of Transition Metal Complexes Featuring Bulky Allyl Ligands
No full textTransition metal allyl complexes are a class of compounds that are both historically important and currently relevant. The parent allyl ligand (C3H5-) can be modified with sterically bulky R groups (R = trimethylsilyl. tert-butyl) at the terminal allyl carbons; complexes with these modified ligands often show much greater stability than analogous complexes of the parent allyl. An excellent example of this is provided by the bis(allyl) complexes of nickel; bis(C3H5)nickel spontaneously decomposes at 20 ˚C, while bis(1,3-trimethysilylallyl)nickel is indefinitely stable under ambient conditions. The stability provided by these ligands can be leveraged in several useful ways. The stability and ease of quantitative characterization made bis(1,3-trimethysilylallyl)nickel a convenient target for the study of factors directing the course of salt metathesis reactions. This investigation demonstrated a limitation in a commonly used parameter for quantifying solvent in mechanochemical systems, identified the most important role that solvent plays in the synthesis of allylnickel compounds by salt metathesis, and generated a preliminary model for choosing an ideal transition metal source for a given salt metathesis reaction. The synthesis of allylnickel complexes featuring the less common (1,3-di-tert-butylallyl) ligand was studied; this demonstrated the generality of stabilization via 1,3-disubsituted allyls and identified one compound as showing unique resistance to the binding of ancillary ligands. The stability of the (1,3-di-tert-butylallyl)nickel fragment was then used in order to synthesize and characterize several derivative allylnickel complexes. These include previously catalytic intermediates not previously isolated and complexes with uncommon supporting ligands. Finally, the potential utility in catalysis that bulky allyl complexes could display is discussed, and some preliminary steps towards such applications is presented
Opinion Formation in Social Networks
No full textA number of selected works on the dynamics of opinions and beliefs in social networks has been discussed. Both Bayesian and non-Bayesian approaches to social learning have been considered, but the analysis has been focused on a simple, tractable and widely used model of updating beliefs - the DeGroot model. The author studied the dynamics of opinions based on the DeGroot model from different points of view. First, its attractive features and shortcomings were discussed and then some of its extensions have been presented. These models are based on the DeGroot updating rule, but addition-ally incorporate the possibility of improvements and enrichments of the framework. (original abstract
Scotland and Dementia Research
No full textdementia researchScotlanddementia carehome careCanadaResearch Infographics - Faculty of Health and Faculty of Arts. Kwantlen Polytechnic University (KPU) researchers/instructors Carol Hansen, Judith DeGroot and Sharon Leitch travelled to Scotland to learn about its national strategic dementia plan and review current research
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Design and Testing of a Foundation Raised Oscillating Surge Wave Energy Converter
No full textOur oceans contain tremendous resource potential in the form of mechanical energy. With the ability to capture and convert the energy carried in surface waves into usable electricity, wave energy converters (WECs) have been a long-held aspiration in ocean renewable energy. One of the most popular wave energy design concepts is the Oscillating Surge Wave Energy Converter (OSWEC). True to their namesake, OSWECs extract energy from the surge force induced by incident waves. In their most basic form, OSWECs are analogous to a bottom-hinged paddle which pitches fore and aft in the direction of wave motion. Most commonly, OSWECs are designed for nearshore use in water depths of less than 20 m where they are mounted to the seafloor at their point of rotation. This work seeks to explore the response and design loads of foundation raised OSWECs for use in deeper waters, unlocking new and greater areas of wave energy resource. A foundation raised OSWEC was designed, built, and tested in a laboratory wave tank. The scale OSWEC was modeled using two methods and compared to data from the experiments. The first of these methods is a highly efficient, analytical approach which derives from the solution to the boundary value problem transformed into elliptical coordinates. Previous validation results demonstrate the analytical model is capable of reproducing results from higher fidelity numerical simulations with computation times on the order of seconds. The second approach combines hydrodynamic coefficients evaluated in WAMIT with the open-source time domain solver WEC-Sim. Two model configurations were observed: the scale OSWEC with no external attachments, and the OSWEC with external torsion springs, as to excite the model at its natural period. The pitch displacement, surge and heave forces, and pitch moment were recorded at the base of the model foundation in response to regular waves with periods ranging from 0.8 s to 2.8 s and heights from 1.5 mm to 14.3 mm. The experimental results show the surge force and pitch moment increase drastically across the observed period range from the addition of external springs. The increase is 20–30 times greater in the most extreme cases. Little to no change in heave forcing was observed between the configurations. The analytical and numerical models capture the natural period of the two configurations well, but the pitch displacement responses of both models fall short of the observations by as much as 60-80% at some periods. Excellent agreement in surge, heave, and pitch loading was obtained between the experimental data and both models. The models were used to simulate a simple power takeoff (PTO) system to approximate the additional PTO torque on the OSWEC. This torque was found to be substantial in magnitude relative to the pitch foundation moment over much of the observed period range.Master of Science in Mechanical Engineering (M.S.M.E.
New intercalation compounds of conjugated polymers. Encapsulation of polyaniline in MoS2.
No full textPT: J; CR: BEIN T, 1989, ANGEW CHEM INT EDIT, V28, P1692 BISSESSUR R, UNPUB COX SD, 1991, J PHYS CHEM-US, V95, P710 DAY P, 1982, MOL CRYST LIQ CRYST, V86, P163 DIVIGALPITIYA WMR, 1989, SCIENCE, V246, P369 DIVIGALPITIYA WMR, 1991, APPL SURF SCI, V48, P572 ENZEL P, 1989, J CHEM SOC CHEM COMM, P1326 ENZEL P, 1989, J PHYS CHEM-US, V93, P6270 ENZEL P, 1992, CHEM MATER, V4, P819 GEE MA, 1986, MATER RES BULL, V21, P543 JOENSEN P, 1986, MATER RES BULL, V21, P457 KANATZIDIS MG, 1987, J AM CHEM SOC, V109, P3797 KANATZIDIS MG, 1989, J AM CHEM SOC, V111, P4139 KANATZIDIS MG, 1990, ADV MATER, V2, P364 KANATZIDIS MG, 1990, CHEM MATER, V2, P222 MEHROTRA V, 1991, SOLID STATE COMMUN, V77, P155 MEHROTRA V, 1992, SOLID STATE IONICS, V51, P115 MURPHY DW, 1979, SCIENCE, V205, P651 NAZAR LF, 1992, J AM CHEM SOC, V114, P6239 PEREIRA C, 1991, J PHYS CHEM-US, V95, P705 PILLION JE, 1991, CHEM MATER, V3, P777 PY MA, 1983, CAN J PHYS, V61, P76 SCHOLLHORN R, 1974, J LESS-COMMON MET, V36, P229 SOMA Y, 1983, CHEM PHYS LETT, V99, P153 SOMOANO RB, 1973, J CHEM PHYS, V58, P697 SOMOANO RB, 1975, J PHYS CHEM-US, V62, P1068 TIEKE B, 1983, MOL CRYST LIQ CRYST, V93, P119 WHITTINGHAM MS, 1976, J ELECTROCHEM SOC, V123, P315 WHITTINGHAM MS, 1978, PROG SOLID STATE CH, V12, P41 WU CG, 1989, POLYM MATER SCI ENG, V61, P969 WYPYCH F, 1992, J CHEM SOC CHEM COMM, V19, P136 YANG D, 1991, PHYS REV B, V43, P12053; NR: 32; TC: 113; J9: CHEM MATER; PG: 2; GA: LC738Source type: Electronic(1
Inclusion of poly(aniline) into MoO3
No full textProtonated emeraldine [poly(aniline)] has been encapsulated in MoO3 by first inserting aniline into its lattice followed by successful polymerization with (NH4)2S2O8; the new material is characterized by X-ray diffraction, IR spectroscopy, scanning electron microscopy and charge transport measurements.PT: J; CR: BEIN T, 1989, SYNTHETIC MET, V29, E163 BISSESSUR R, UNPUB DESILVESTRO J, 1990, J ELECTROCHEM SOC, V137, C5 ENZEL P, 1989, J PHYS CHEM-US, V93, P6270 GENIES EM, 1990, SYNTHETIC MET, V36, P139 INOUE H, 1987, J ELECTROANAL CH INF, V233, P291 KANATZIDIS MG, 1987, J AM CHEM SOC, V109, P3797 KANATZIDIS MG, 1989, J AM CHEM SOC, V111, P4139 KANATZIDIS MG, 1989, SOLID STATE IONICS, V32, P594 KANATZIDIS MG, 1989, SYNTHETIC MET, V28, C89 KANATZIDIS MG, 1990, CHEM MATER, V2, P222 MURPHY DW, 1979, SCIENCE, V205, P651 NAZAR LF, 1991, MATER RES SOC S P, V210, P417 NAZAR LF, 1992, J AM CHEM SOC, V114, P6239 SCHOLLHORN R, 1980, J LESS-COMMON MET, V71, P71 WHITTINGHAM MS, 1976, J ELECTROCHEM SOC, V123, P315 WU CG, 1989, POLYM MATER SCI ENG, V61, P969 WU CG, 1990, ADV MATER, V2, P364 WU CG, 1991, LOWER DIMENSIONAL SY, P427 ZUO F, 1987, PHYS REV B, V36, P3475; NR: 20; TC: 66; J9: J CHEM SOC CHEM COMMUN; PG: 3; GA: KY858Source type: Electronic(1
On Bayes estimates
No full textAbstractIn this paper the author tries to give general conditions for the existence of Bayes estimates and for the consistency of sequences of Bayes estimates.In Section 3 we prove existence theorems for Bayes estimates, which contain those of DeGroot and Rao [3], as a special case. The proof is based on a theorem of Landers [5].Section 4 gives a characterization of Bayes estimates with convex loss and linear decision space. This theorem is also a generalization of a similar theorem of DeGroot and Rao [3].In Section 5 we generalize the theory of minimum contrast estimates (the foundations of which were laid by Huber [4], cf. Pfanzagl [6]) in such a way that we can apply it to the theory of Bayes estimates.Section 6 tries to give a general theory of consistency for Bayes estimates using the martingale argument of Doob [1] and the theory of minimum contrast estimates. Confer in this connection the results of Schwartz [8].Section 7 contains some auxiliary results
A framework to analyze opinion formation models
No full textComparing model predictions with real data is crucial to improve and validate a model. For opinion formation models, validation based on real data is uncommon and difficult to obtain, also due to the lack of systematic approaches for a meaningful comparison. We introduce a framework to assess opinion formation models, which can be used to determine the qualitative outcomes that an opinion formation model can produce, and compare model predictions with real data. The proposed approach relies on a histogram-based classification algorithm, and on transition tables. The algorithm classifies an opinion distribution as perfect consensus, consensus, polarization, clustering, or dissensus; these qualitative categories were identified from World Values Survey data. The transition tables capture the qualitative evolution of the opinion distribution between an initial and a final time. We compute the real transition tables based on World Values Survey data from different years, as well as the predicted transition tables produced by the French-DeGroot, Weighted-Median, Bounded Confidence, and Quantum Game models, and we compare them. Our results provide insight into the evolution of real-life opinions and highlight key directions to improve opinion formation models.Team Tamas Keviczk
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