scholarly journals One-dimensional titanate nanotube materials: heterogeneous solid catalysts for sustainable synthesis of biofuel precursors/value-added chemicals—a review

Author(s):  
Aderemi Timothy Adeleye ◽  
Kingsley I. John ◽  
Promise Goodness Adeleye ◽  
Amos Adeleke Akande ◽  
Oluwakemi Oluwabunmi Banjoko
2020 ◽  
Vol 12 (1) ◽  
pp. 12-35
Author(s):  
Piotr Jedynak ◽  
Sylwia Bąk

AbstractObjective: The purpose of this text is to identify approaches to defining and subsequently reviewing the definitions of uncertainty and risk as interdisciplinary terms which are of key importance in modern management.Methodology: The work is theoretical. The main method used in the research process was the analysis of scientific literature. A one-dimensional logical classification method was also used, in order to categorize approaches to defining uncertainty and risk, satisfying the exhaustive and mutually exclusive criteria in the selection of categories of approaches.Findings: The main results of the work are: 1) identification of approaches to defining uncertainty and risk, 2) interdisciplinary review of definitions of uncertainty and risk indicating the criteria to distinguish between the two, and 3) determination of the meaning of the terms uncertainty and risk in modern management.Value Added: Considering the approaches to defining uncertainty and risk taken from many fields and disciplines of science, this text is a compendium of theoretical knowledge for the proper understanding and meaning of these concepts in management.Recommendations: The research findings can have implications for both management theory as well as the practice of organization management.


1994 ◽  
Vol 368 ◽  
Author(s):  
Mark R. Antonio ◽  
J. Malinsky ◽  
L. Soderholm

ABSTRACTNa+ in the Preyssler heteropolytungstate anion [NaP5W30O110]14− can be exchanged for a trivalent lanthanide ion. The potential significance of this new class of lanthanide heteropolyanions relates to their applications in catalysis science. This view follows from the fact that Keggin heteropolyanions and their free acids are used as heterogeneous solid catalysts and homogeneous solution catalysts. We describe synthetic conditions that lead to the incorporation of Ce3+ and Pr3+ within the Preyssler anion, and the coprecipitation of Ce3+ and the Preyssler anion. Initial studies indicate that the latter, coprecipitated, material deserves study for bifunctional catalytic activity.


Geophysics ◽  
1984 ◽  
Vol 49 (7) ◽  
pp. 1032-1040 ◽  
Author(s):  
Baxter H. Armstrong

Some one‐dimensional models of a heterogeneous solid are presented consisting of a succession of slabs with different anharmonic properties. The equation for the temperature variation in these models due to passage of a longitudinal elastic wave can be solved exactly in the approximation of weak attenuation. The solutions are given in terms of the forced oscillation plus the temperature wave solutions to the homogeneous equation needed to match the boundary conditions of continuity of temperature and thermal current. Thermoelastic attenuation due to this temperature variation is compared to that of Zener’s classical approach. For periodic arrangement of slab properties or upon use of Zener’s boundary condition of vanishing thermal current, the temperature‐wave approach reproduces Zener‐type attenuation. However, a succession of slabs with a random, uncorrelated distribution of the Gruneisen constant leads to a new result with attenuation proportional to the three‐halves power of the wave frequency in the low‐frequency limit. The results are discussed in the context of seismoacoustic wave attenuation.


2017 ◽  
Vol 53 (79) ◽  
pp. 10851-10869 ◽  
Author(s):  
Amarajothi Dhakshinamoorthy ◽  
Abdullah M. Asiri ◽  
Hermenegildo Garcia

This Feature article describes on the recent developments in the use of metal organic frameworks as heterogeneous solid catalysts for the selective alcohol oxidation by either tuning the actives sites around the metal centre, or anchoring them on the ligands or using the pores to embed metal nanoparticles inside.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1445
Author(s):  
Francisco G. Cirujano ◽  
Rafael Luque ◽  
Amarajothi Dhakshinamoorthy

Metal–organic frameworks (MOFs) have become one of the versatile solid materials used for a wide range of applications, such as gas storage, gas separation, proton conductivity, sensors and catalysis. Among these fields, one of the more well-studied areas is the use of MOFs as heterogeneous catalysts for a broad range of organic reactions. In the present review, the employment of MOFs as solid catalysts for the Henry reaction is discussed, and the available literature data from the last decade are grouped. The review is organized with a brief introduction of the importance of Henry reactions and structural properties of MOFs that are suitable for catalysis. The second part of the review discusses the use of MOFs as solid catalysts for the Henry reaction involving metal nodes as active sites, while the third section provides data utilizing basic sites (primary amine, secondary amine, amides and urea-donating sites). While commenting on the catalytic results in these two sections, the advantage of MOFs over other solid catalysts is compared in terms of activity by providing turnover number (TON) values and the structural stability of MOFs during the course of the reaction. The final section provides our views on further directions in this field.


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