Viktor V Slobodyan

6494616, Dec 17, 2002

Aug 4, 2000

09/632405

Eugene Tokhtuev - Duluth MN
Robert M. Carlson - Duluth MN
Christopher J. Owen - Duluth MN
Anatoly Skirda - Duluth MN
Viktor Slobodyan - Duluth MN
Alexander Tokhtuev - Duluth MN

Regents of the University of Minnesota - Minneapolis MN

G01K 300

374137, 374142, 374143, 374166, 374183, 34087011, 34087013

A sensor array includes a plurality of sensors connected to two or more groups of wires such that individual sensors can be addressed. No two sensors are connected to the same two wires. The groups of wires are connected to multiplexers or the like to address particular wires connecting a unique sensor. Dramatically improved accuracy is obtained by connecting rectifiers in series with the sensors to significantly reduce reverse current through a sensor that can lead to significant errors. In some preferred embodiments, the array includes a plurality of temperature sensors, especially for use in measuring temperature at different depths in a body of water.

6842243, Jan 11, 2005

Dec 10, 2002

10/315142

Eugene Tokhtuev - Duluth MN, US
Christopher Owen - Duluth MN, US
Anatoly Skirda - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
José Goin - Duluth MN, US

Apprise Technologies, Inc. - Duluth MN

G01N 2100

356338

A small size turbidity sensor for underwater in-situ measurements in the wide range of turbidity values is disclosed that may be integrated into a housing with other underwater sensors. The turbidity sensor incorporates micro focusing devices and light stop that gives no divergence excitation beam with convergence less than 1. 5 degrees and the measuring angle between the optical axis of the incident radiation and mat of the diffused radiation 90 2. 5 degrees. Another embodiment includes internal and external optical calibrators that allows the sensor to work longer without human intervention.

6916219, Jul 12, 2005

Nov 8, 2002

10/290403

Eugene Tokhtuev - Duluth MN, US
Anatoly Skirda - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
Christopher Owen - Duluth MN, US

Apprise Technologies, Inc. - Duluth MN

B63B022/20

441 29

An automated system for periodically sampling water bodies, such as lakes, and delivering the test results to a remote computer using a communication system. In particular, the system has a variable buoyancy profiler with a dynamic buoyancy compensator responding approximately linear to a water pressure created by an external water body so as to actively or passively interact with an external force or pressure thereby moving the profiler to a target depth.

7049602, May 23, 2006

Jul 30, 2003

10/629754

Eugene Tokhtuev - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
Anatoly Skirda - Duluth MN, US
Christopher J. Owen - Duluth MN, US
Jose A. Goin - Duluth MN, US
Christopher A. Buck - Duluth MN, US

G01J 1/42
G02B 26/00
G02B 6/00

250372, 359290, 385140

The invention provides a radiation sensor including a housing, an attenuator with at least one cavity for attenuating optical radiation, and a detector, as well as an optical attenuator including an attenuator body, an entrance with one multi-stage input opening or plural input openings, and means for transferring radiation inside of the attenuator body and then to a detector. The invention further provides methods for using the radiation sensor or the optical attenuator.

7198755, Apr 3, 2007

Sep 12, 2002

10/241451

Eugene Tokhtuev - Duluth MN, US
Anatoly Skirda - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
Christopher Owen - Duluth MN, US

Apprise Technologies, Inc. - Duluth MN

G01N 21/00
G01N 21/75
G01N 21/62
G01N 21/76
B32B 5/02

422 8202, 422 50, 422 52, 422 55, 422 56, 422 57, 422 58, 422 681, 422 8205, 422 8206, 422 8207, 422 8209, 436 43, 436164, 436171, 436172

A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

7416701, Aug 26, 2008

Dec 13, 2005

11/299784

Eugene Tokhtuev - Duluth MN, US
Anatoly Skirda - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
Christopher Owen - Duluth MN, US

Ecolab Inc. - St. Paul MN

G01N 21/64
G01N 21/66
G01N 15/06
G01N 33/00
C12Q 1/68

422 8208, 422 50, 422 681, 422 8205, 422 8206, 422 8207, 422 8209, 422 8211, 436164, 356432, 356213, 295921, 29592

A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

7491366, Feb 17, 2009

Mar 3, 2005

11/070647

Eugene Tokhtuev - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
Christopher J. Owen - Duluth MN, US
Christopher A. Buck - Minneapolis MN, US
Anatoly Skirda - Duluth MN, US
William M. Christensen - Hibbing MN, US

Ecolab Inc. - St. Paul MN

G01N 21/00

422 8205

A portable multi-channel device for optically testing of a liquid sample includes a controller; and a sample holder with a cylindrical sample compartment and at least two optical channels respectively for measuring turbidity of the sample liquid and for measuring one other optical property of the sample liquid. Each of the optical channels including: a light source placed at one end of the channel, a main detector placed across the sample compartment from the light source, a reference detector for measuring an intensity of light emitted by the light source, and an excitation focusing optic for directing a light emitted by the light source through the sample compartment towards the main detector. Signals from the reference detector of the channel, the main detector of the channel, and another main detector of another channel perpendicular to the channel are processed by the controller to evaluate the turbidity of the liquid sample.

7550746, Jun 23, 2009

May 31, 2007

11/809208

Eugene Tokhtuev - Duluth MN, US
Christopher J. Owen - Duluth MN, US
Viktor Slobodyan - Duluth MN, US
Anatoly Skirda - Duluth MN, US
Paul Schilling - Duluth MN, US
Anna Pilipchenko - Duluth MN, US
Paul R. Kraus - Apple Valley MN, US
Katherine M. Sanville - White Bear Lake MN, US
Joseph Phillip Erickson - Cloquet MN, US

Ecolab Inc. - Saint Paul MN

G01N 21/64
G01J 3/00

2504611, 356 51

An ultraviolet (UV) fluorometric sensor measures a chemical concentration in a sample based on the measured fluorescence of the sample. The sensor includes a controller, at least one UV light source, and at least one UV detector. The sensor emits UV light in a wavelength range of 245-265 nm from the light source through the sample in an analytical area. The UV detector measures the fluorescence emission from the sample. The controller transforms output signals from the UV detector into fluorescence values or optical densities for one or more wavelengths in the wavelength range of 265-340 nm. The controller calculates the chemical concentration of the chemical in the sample based on the measured fluorescence emissions.