Production of Nanostructures Under Ultraturbulent Collision Reaction Conditions - Application to Catalysts, Superconductors, CMP Abrasives, Ceramics, and Other Nanoparticles

MRS Proceedings ◽

10.1557/proc-775-p9.7 ◽

2003 ◽

Vol 775 ◽

Author(s):

Irwin J. Gruverman ◽

Jeffrey R. Thumm

Keyword(s):

Size Distribution ◽

Chemical Reactor ◽

Mixing Conditions ◽

Reaction Conditions ◽

Direct Precipitation ◽

Reaction Region ◽

The One ◽

Continuous Chemical ◽

Interaction Chamber ◽

Reactant Solution

AbstractThe development, operation and applications of a novel continuous chemical reactor system are described. The system, known as a Multiple Stream Mixer/Reactor (or MMR), produces nanoparticles by direct precipitation from two or more reactant solution streams in an extreme energy density, ultraturbulent, collision reaction region. Sensors and a control system are employed to assure constant mixing conditions and desired stoichiometry in the reaction region. The interaction chamber is designed to allow macro-, meso- and micromixing during processing. This allows control of product purity, yield, size, size distribution, and phase purity. Typical nanoparticle diameters in the one to ten nanometer range are often achievable, with tight size distribution. The MMR can be scaled from development quantities to tons/hour for production applications.

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Unravelling the one-pot conversion of biomass-derived furfural and levulinic acid to 1,4-pentanediol catalysed by supported RANEY® Ni–Sn alloy catalysts

RSC Advances ◽

10.1039/d1ra06135f ◽

2022 ◽

Vol 12 (1) ◽

pp. 241-250

Author(s):

Rodiansono ◽

Maria Dewi Astuti ◽

Kamilia Mustikasari ◽

Sadang Husain ◽

Fathur Razi Ansyah ◽

...

Keyword(s):

Levulinic Acid ◽

Reaction Conditions ◽

One Pot ◽

The One ◽

Alloy Catalysts

The RANEY® Ni–Sn(x) alloy catalysed the one-pot conversion of biomass-derived furfural and levulinic acid to allow remarkable yield of 1,4-pentanediol (up to 90%) under the mild reaction conditions.

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An investigation of processes controlling the evolution of the boundary layer aerosol size distribution properties at the Swedish background station Aspvreten

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-4-4507-2004 ◽

2004 ◽

Vol 4 (4) ◽

pp. 4507-4543 ◽

Cited By ~ 2

Author(s):

P. Tunved ◽

J. Ström ◽

H.-C. Hansson

Keyword(s):

Size Distribution ◽

Wet Deposition ◽

Source Area ◽

Aerosol Size Distribution ◽

Back Trajectory ◽

Main Process ◽

Size Distributions ◽

Back Trajectory Analysis ◽

The One ◽

Precipitating Clouds

Abstract. Aerosol size distributions have been measured at the Swedish background station Aspvreten (58.8° N, 17.4° E). Different states of the aerosol were determined using a novel application of cluster analysis. The analysis resulted in eight different clusters capturing the different stages of the aerosol lifecycle. The aerosol was interpreted as belonging to fresh, intermediate and aged type of size distribution and different magnitudes thereof. With aid of back trajectory analysis we present statistics concerning the relation of source area and different meteorological parameters using a non-lagrangian approach. Source area is argued to be important although not sufficient to describe the observed aerosol properties. Especially processing by clouds and precipitation is shown to be crucial for the evolution of the aerosol size distribution. As much as 60% of the observed size distributions present features likely related to cloud processes or wet deposition. The lifetime properties of different sized aerosols are discussed by means of measured variability. Processing by non-precipitating clouds most obviously affect aerosols in the size range 100 nm and larger. This indicates an approximate limit for activation in clouds to 100 nm in this type of environment. The aerosol lifecycle is discussed. Size distributions bearing signs of recent new particle formation (~30% of the observed size distributions) represent the first stage in the lifecycle. Aging may proceed in two directions: either growth by condensation and coagulation or processing by non-precipitating clouds. In both cases mass is accumulated. Wet removal is the main process capable of removing aerosol mass. Wet deposition is argued to be an important mechanism in reaching a state where nucleation may occur (i.e. sufficiently low aerosol surface area) in environments similar to the one studied.

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A novel three-component reaction between isocyanides, alcohols or thiols and elemental sulfur: a mild, catalyst-free approach towards O-thiocarbamates and dithiocarbamates

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.15.155 ◽

2019 ◽

Vol 15 ◽

pp. 1523-1533 ◽

Cited By ~ 1

Author(s):

András György Németh ◽

György Miklós Keserű ◽

Péter Ábrányi-Balogh

Keyword(s):

Elemental Sulfur ◽

Building Blocks ◽

Reaction Conditions ◽

One Pot ◽

Catalyst Free ◽

Synthetic Procedure ◽

Three Component Reaction ◽

Wide Range ◽

Organic Chemist ◽

The One

A new multicomponent reaction has been developed between isocyanides, sulfur and alcohols or thiols under mild reaction conditions to afford O-thiocarbamates and dithiocarbamates in moderate to good yields. The one-pot reaction cascade involves the formation of an isothiocyanate intermediate, thus a catalyst-free synthesis of isothiocyanates, as valuable building blocks from isocyanides and sulfur is proposed, as well. The synthetic procedure suits the demand of a modern organic chemist, as it tolerates a wide range of functional groups, it is atom economic and easily scalable.

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Experimental and modelling aspects of the reactive extrusion process

Mechanics & Industry ◽

10.1051/meca/2019052 ◽

2019 ◽

Vol 20 (8) ◽

pp. 803 ◽

Cited By ~ 3

Author(s):

Philippe Cassagnau ◽

Véronique Bounor-Legaré ◽

Bruno Vergnes

Keyword(s):

Chemical Reactor ◽

Reactive Extrusion ◽

Extrusion Process ◽

Industrial Applications ◽

Twin Screw Extruders ◽

Single Screw Extruders ◽

Twin Screw ◽

On Line ◽

Screw Extruders ◽

Continuous Chemical

Reactive extrusion consists in using an extruder as a continuous chemical reactor. It is not a recent process, but it has been rapidly developed during the last thirty years and is more and more used today for the chemical modification of existing polymers. Among the various extrusion systems (single screw extruders, counter- and corotating twin-screw extruders, co-kneaders), the corotating twin-screw extruders are today the most widely used in reactive extrusion. After a presentation of the main advantages and drawbacks of the reactive extrusion, we will describe the way to control the process through on-line and in-line monitoring. Then, a modelling approach based on continuum mechanics will be presented, followed by an example of industrial applications of this particular process.

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Harvesting sugar-beet seed

The Journal of Agricultural Science ◽

10.1017/s0021859600026915 ◽

1974 ◽

Vol 83 (3) ◽

pp. 435-442 ◽

Cited By ~ 4

Author(s):

P. C. Longden

Keyword(s):

Sugar Beet ◽

Size Distribution ◽

Plant Height ◽

Seed Yield ◽

Traditional Method ◽

Germination Percentage ◽

Viable Seed ◽

Chlormequat Chloride ◽

Seed Crop ◽

The One

SummaryComparisons of the effects of harvesting sugar-beet seed by the traditional method of tripodding with barn drying, swathing followed by threshing with a pick-up combine or desiccation with diquat followed by direct combine harvesting showed that there were no consistent or large effects on seed yield, germination, monogermity or size distribution. Thus the best method will be the one which is easiest and/or cheapest, which at present is swathing followed by pick-up combine threshing.Sprays of NAA or 2,4,5-T at 10 or 100 mg a.i./l water before or after flowering had no effect on seed yield or germination and efforts to restrict the loss by shedding of large viable seed failed. Neither chemical decreased germination percentage by setting parthenocarpic seed. Attempts were made to dwarf the 2 m high seed crop to make it suitable for direct combine harvesting. Daminozide sprayed at 1000, 5000 or 10000 mg a.i./l water before or after the winter did not affect plant height, seed yield, germination, monogermity or size distribution. Chlormequat chloride applied similarly dwarfed plants by up to 18% but this was not enough to give a crop less than 1 m high suitable for direct combine harvesting. It did not affect seed yield, germination, monogermity or size distribution. Ethephon sprayed at 10, 100 or 1000 mg a.i./l water when plants were bolting had no detected effects. Chlorflurecolmethyl was sprayed at 10 or 100 before bolting or 1, 10 or 100 mg a.i./l water afterwards. Plants sprayed with the 100 mg/1 solution were dwarfed to less than 1 m high but the treatment was unsuccessful because it greatly reduced seed yield and germination; monogermity was not affected but a much greater proportion of seed fell into the small size grades.

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Microwave Assisted Three Component Reaction Conditions to Obtain New Thiazolidinones with Different Heterocyclic Skeletons

Proceedings ◽

10.3390/ecsoc-23-06474 ◽

2019 ◽

Vol 41 (1) ◽

pp. 38

Author(s):

Fernando J. Lorenzo ◽

Romina A. Ocampo ◽

Sandra D. Mandolesi

Keyword(s):

Microwave Irradiation ◽

Thioglycolic Acid ◽

Aldehyde Group ◽

Green Solvent ◽

Reaction Products ◽

Reaction Conditions ◽

One Pot ◽

Microwave Assisted ◽

Three Component Reaction ◽

The One

We present here a new proposal for the “one pot” generation of new 4-thiazolidinones (9a–e) through a multicomponent reaction under microwave irradiation conditions, using aromatic and heteroaromatic amines (8a–e), absolute ethanol as a “green” solvent and modifying the aldehyde group in the glycosidic residue, synthesized from D-mannitol. The study is focused in the variation of the irradiation times and the concentration of thioglycolic acid in order to study the possibility of controlling the structure and/or stereochemistry of the products formed in the reaction. Thiazolidinones 9a–d were obtained with a 69–82% The generation of the corresponding reaction products were monitored by TLC and CG-MS, taking reaction aliquots. The conditions reaction proved to be chemoselective depending on the excess of acid and irradiation times.

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Universality in the One-Dimensional Self-Organized Critical Forest-Fire Model

Zeitschrift für Naturforschung A ◽

10.1515/zna-1994-0907 ◽

1994 ◽

Vol 49 (9) ◽

pp. 856-860

Author(s):

Barbara Drossel ◽

Siegfried Clar ◽

Franz Schwabl

Keyword(s):

Size Distribution ◽

Forest Fire ◽

Nearest Neighbor ◽

The Self ◽

One Dimension ◽

Fire Model ◽

One Dimensional ◽

Self Organized ◽

Forest Fire Model ◽

The One

Abstract We modify the rules of the self-organized critical forest-fire model in one dimension by allowing the fire to jum p over holes of ≤ k sites. An analytic calculation shows that not only the size distribution of forest clusters but also the size distribution of fires is characterized by the same critical exponent as in the nearest-neighbor model, i.e. the critical behavior of the model is universal. Computer simulations confirm the analytic results.

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