75 research outputs found
Computer Simulation Tests of Feedback Error Learning Controller with IDM and ISM for Functional Electrical Stimulation in Wrist Joint Control
Feedforward controller would be useful for hybrid Functional Electrical Stimulation (FES) system using powered orthotic devices. In this paper, Feedback Error Learning (FEL) controller for FES (FEL-FES controller) was examined using an inverse statics model (ISM) with an inverse dynamics model (IDM) to realize a feedforward FES controller. For FES application, the ISM was tested in learning off line using training data obtained by PID control of very slow movements. Computer simulation tests in controlling wrist joint movements showed that the ISM performed properly in positioning task and that IDM learning was improved by using the ISM showing increase of output power ratio of the feedforward controller. The simple ISM learning method and the FEL-FES controller using the ISM would be useful in controlling the musculoskeletal system that has nonlinear characteristics to electrical stimulation and therefore is expected to be useful in applying to hybrid FES system using powered orthotic device
Cardiomyopathy: Recent Findings
In 1957, Wallace Brigden published an article on the Lancet, such as uncommon myocardial diseases: the non-coronary cardiomyopathy. In this article, he mentioned that “the term cardiomyopathy is used here to indicate isolated noncoronary myocardial disease.” Then “cardiomyopathy” has become a commonly used term in the cardiovascular field, and has been defined and classified by many researchers and academic societies. The basic concept of cardiomyopathy is a group of diseases with mechanical and/or electrophysiological dysfunction of the ventricles, and cardiomyopathy is distinguished with normal ischemic heart disease, valvular disease, and hypertensive heart disease. It can often cause heart failure and cardiac death. In this chapter, we describe the classification, details, and treatment of cardiomyopathy, and iPS cell from pathological myocardium
The isopropylation of naphthalene with propene over H-mordenite: The catalysis at the internal and external acid sites
The isopropylation of naphthalene (NP) with propene over H-Mordenite (MOR) was studied under a wide range of reaction parameters: temperature, propene pressure, period, and NP/MOR ratio. Selective formation of 2,6-diisopropylnaphthalene (2,6-DIPN) was observed at reaction conditions, such as at low reaction temperature, under high propene pressure, and/or with high NP/MOR ratio. However, the decrease in the selectivities for 2,6-DIPN was observed at reaction conditions such as at high temperature, under low propene pressure, and/or with low NP/MOR ratio. The selectivities for 2,6-DIPN in the encapsulated products were remained high and constant under all reaction conditions. These results indicate that the selective formation of 2,6-DIPN occurs through the least bulky transition state due to the exclusion of the bulky isomers by the MOR channels. The decrease in the selectivities for 2,6-DIPN are due to the isomerization of 2,6-DIPN to 2,7-DIPN at the external acid sites, directing towards thermodynamic equilibrium of DIPN isomers
New Heat-Resistant and Soluble Aramids Synthesized by Palladium-Catalyzed Carbonylation-Polycondensation
High catalytic activity of As-Synthesized, Ordered Porous Silicate-Quaternary ammonium composite for knoevenagel condensation
Alkylation of biphenyl over zeolites: shape-selective catalysis in zeolite channels
Steric interaction of reactants, products, and transition state intermediates with zeolites with 12- and 14-membered ring pore entrances is discussed in the alkylation of biphenyl (BP) by propene, 1-butene, and 2-methylpropene as alkylating agents. The selectivities for the least bulky 4,4′-dialkylbiphenyl (4,4′-DAB) depended on\ua0the types of zeolite and alkylating agent. The zeolites are classified as two types: Category I: mordenite (MOR), SSZ-24 (AFI), SSZ-31 (STO), CIT-5 (CFI), MCM-68 (MSE), and ZSM-12 (MTW) with straight (or slightly corrugated) channels with 12-MR or 14-MR pore entrances. Category II: SSZ-42 (IFR), SSZ-55 (ATS), SSZ-60 (SSY), Y (FAU), β (BEA), CIT-1 (CON), UTD-1 (DON), and SSZ-53 (SFH) with large channels. Category I zeolites have shape-selective natures in their channels in the isopropylation. Among them, MOR supported the highest selectivities around 85\ua0% for 4,4′-diisopropylbipneyl (4,4′-DIPB) at moderate temperatures\ua0as 250 C. The selectivities of 4,4′-DIPB are: MOR\ua0>\ua0AFI, MSE\ua0>\ua0MTW, CFI, STO: the differences are due to the recognition of 4,4′- and 3,4′-DIPB by the channels. Category II zeolites allow the accommodation and the formation of bulky DIPB isomers in their channels, resulting in non-shape selective catalysis under kinetic and/or thermodynamic controls. Bulky alkylating agents, 1-butene and 2-methylpropene, enhance selective formation of the least bulky 4,4′-DAB: 4,4′-di-sec-butylbiphenyl (4,4′-DSSB) and 4,4′-di-tert-butylbiphenyl (4,4′-DTBB), respectively, even over Category II zeolites. The bulky moieties enhance the exclusion of bulky isomers by their interaction with zeolite channels. The selectivities for 4,4′-DSSB were increased remarkably to higher than 80\ua0% for Category I zeolites and to 70\ua0% for ATS in Category II zeolites\ua0in the sec-butylation. However, kinetic and thermodynamic controls still worked with the formation of bulky isomers over Category II zeolites: IFR, FAU, BEA, CON, DON, and SFH in\ua0the sec-butylation. The high selectivities for 4,4′-DTTB higher than 80\ua0% were observed for the zeolites, except FAU in the tert-butylation. These results indicate that the selectivities for 4,4′-DAB are controlled primarily by space and shape of zeolite channels for active sites, and not always by the size of pore entrances
Shape-Selective Catalysis in the Alkylation of Naphthalene: Steric Interaction with the Nanospace of Zeolites
Steric interaction of reagents with nanospace of zeolites was studied in alkylation: isopropylation, sec-butylation, and tert-butylation of naphthalene (NP) over several large-pore zeolites to elucidate the mechanism of shape-selective catalysis. Selectivities for β,β- and 2,6-dialkylnaphthalene (DAN) were influenced by the type of zeolite and bulkiness of alkylating agent. Shape-selective formation of β,β- and 2,6-diisopropylnaphthalene (DIPN) occurred only over H-mordenite (MOR) in the isopropylation of NP. Bulky α,α- and α,β-DIPN are excluded because of steric restriction at their transition states by the MOR channels, resulting in the selective formation of β,β- and 2,6-DIPN. AFI (SSZ-24) gave also high selectivities for 2,6-DIPN, and CFI (CIT-5) and MSE (MCM-68) gave high selectivities for β,β-DIPN. The lower selectivities for 2,6-DIPN were observed over the zeolites, ATS (SSZ-55), IFR (SSZ-42), DON (UTD-1), SFH (SSZ-53), FAU (Y-zeolite), BEA (zeolite β), and CON (CIT-1). Their channels allow the accommodation of bulky isomers, resulting in the catalysis under kinetic and/or thermodynamic controls. The selectivities for β,β- and 2,6-DAN were enhanced with the increase in bulkiness of alkylating agents: 1-butene for sec-butylation and 2-methylpropene for tert-butylation, even over zeolites with large pores and channels: the transition states of the least bulky isomers only fit the channels, and the other bulky isomers are excluded by steric restriction of the channels. However, tert-butylation over FAU, BEA, and CON had selectivities of around 50-60% for 2,6-DTBN, and almost 100% selectivities for β,β-DTBN. These zeolites cannot recognize the differences between 2,6- and 2,7-DTBN, but they can differentiate β,β-DTBN from the other isomers. The results indicate that the fitting of the least bulky isomers to zeolite channels, resulting in the exclusion of other bulky isomers, is a key for highly shape-selective catalysis
Synthesis of [Al]-SSZ-31 Molecular Sieves using [Al]-Beta Zeolite ([Al]-BEA) as precursors
Synthesis of Heat-Resistant Polyester containing rigid biphenyl moiety by Palladium-Catalyzed Carbonylation-Polycondensaiton
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