US5229041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making microscopic particles containing imbedded fluorescent dyes
Assignee: Johns Hopkins University
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Filing: 1992-01-21
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Granted: 1993-07-20
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Expires: 2012-01-21
Abstract
Abstract Microscopic, neutrally buoyant particles containing fluorescing compounds used for tracers of large scale turbulent flows. The particles are generated by dissolving acrylics in a solvent and mixing the solution with fluorescing dyes. This mixture is sprayed into a heated chamber where the solvent evaporates, and the solid acrylic with the imbedded dye settles on the bottom of the chamber. The dust is collected, and the particles are separated according to size using a filter. Dye residue on the particles' surface is washed leaving the dye imbedded within the particles. The particles are then used within flow fields.
Inventors
- 👤 Joseph Katz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:37
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/122; C08K; C08K5/00; C08K5/0008; C08K5/0041; C09; C09B; C09B67/00; C09B67/006; C09B67/0061; C09B67/0097; C09K; C09K11/00; C09K11/06; C08J2333/00; C08J2333/04; C08J2333/06; C08J2333/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
74 words
A method for forming microscopic particles for use in velocimetry of turbulent flows comprising the steps of: adding an acrylic resin to a solvent, thereby forming an acrylic solution; adding dye to said solution; spraying the solution having dye added thereto into a heated chamber; evaporating said solvent; collecting the microscopic particles that remain; and washing in an aqueous solution the collected particles so as remove any dye from the surface of the particle.
Claim 2
Independent Claim
74 words
A method for forming microscopic particles for use in velocimetry of turbulent flows comprising the steps of: adding an acrylic resin to a solvent, thereby forming an acrylic solution; adding dye to said solution; spraying the solution having dye added thereto into a heated chamber; evaporating said solvent; collecting the microscopic particles that remain; and washing in an aqueous solution the collected particles so as remove any dye from the surface of the particle.
Claim 3
Dependent Claim
29 words
A method as claimed in claim 1, wherein said adding dye step includes adding powdered fluorescent dye to said solution and stirring the solution as the dye is added.
Claim 4
Dependent Claim
32 words
A method as claimed in claim 2, wherein said adding dye step includes selecting the dye from the group consisting of Rhodamine 6G, Rhodamine B, DCM, 2,7 Dichlorofluorescein, Fluorescein and combinations thereof.
Claim 5
Dependent Claim
31 words
A method as claimed in claim 1, wherein said spraying step includes atomizing said solution having the dye added thereto by spraying the mixture under high pressure into said heated chamber.
Claim 6
Dependent Claim
44 words
A method as claimed in claim 1, wherein said evaporating step includes heating the chamber to a temperature greater than the boiling point of said solvent and thus evaporating the solvent from the dye/solution mixture and leaving the dye embedded within the acrylic resin.
Claim 7
Dependent Claim
29 words
A method as claimed in claim 1, wherein said collecting step includes allowing the particles to settle into collection trays located at a lower portion of said heated chamber.
Claim 8
Dependent Claim
26 words
A method as claimed in claim 1, wherein said washing step includes immersing the collected particles in water and filtering the particle/water mixture to remove solids.
Claim 9
Dependent Claim
16 words
A method as claimed in claim 1, further comprising the step of drying the washed particles:
Claim 10
Dependent Claim
21 words
A method as claimed in claim 1, wherein adding said acrylic resin step includes choosing the acrylic resin to be Methacrylate.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 9, wherein choosing the acrylic resin includes choosing a Methacrylate grade of 2008.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |