Nathan Schattke - Academia.edu (original) (raw)

Papers by Nathan Schattke

WORLD SCIENTIFIC eBooks, Dec 1, 2008

Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a ... more Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a bio-aerosol collector or from an environmental water source, into a volume of 1 to 2 ml. is achieved by a liquid flow system including a reversible filter through which filtered liquid can be recirculated or disposed of and from which a concentrated sample is recovered by opening a solenoid valve leading to a detector or to a collection container and reversing the pump for a short time. The reversing action flushes the collected particles off the filter and into the detector or container. The effectiveness of this approach was demonstrated by measuring the cumulative fluorescence of 1-micron-size blue fluorescent microspheres versus cumulative volume withdrawn from our WEP collector after capture from an aerosol suspension of about 140 particles/ml drawn from a test chamber over a 5-minute period at a sampling rate of 500 liters/minute. As the liquid was being withdrawn from the WEP collector, it was filtered at a rate of 1 ml/second and the filter back-flushed with small portions of filtrate at 1-minute intervals. The relative cumulative concentration of captured particles in the first back-flushed 1-ml fraction was around 56 as compared with a value of 1.4 in the first 60-ml filtered fraction, which constitutes a liquid-to-liquid concentration enhancement by a factor of 40 and an air-to-liquid concentration factor of >1.25 × 106.

The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained.

The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained. Much w... more The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained. Much work was performed on the Kamina as it has the ability to respond to low (less than 10 ppb) concentrations ofhydrazine compounds. We were able to tell the difference between Hydrazine (Hz) and Monomethylhydrazine (MMH) in standard clean humid air. We were able to detect MMH in reduced pressure (1/3 atm) at about 250 ppb, however the training set was to far from the real situation to be useful now. Various engineering and usability aspects of both the noses was noted, especially the software. One serious physical engineering flaw was remedied in the Kamina system. A gas flow manifold was created for the Sam system. Different chips were evaluated for the Kamina system. It is still unclear if they can be exchanged without retraining the software. 171 https://ntrs.nasa.gov/search.jsp?R=20020050543 2019-11-16T15:11:52+00:00Z

The electronic nose is a method of using several sensors in conjunction to identify an unknown ga... more The electronic nose is a method of using several sensors in conjunction to identify an unknown gas. Statistical analysis has shown that a large number of training exposures need to be performed in order to get a model that can be depended on. The number of training exposures needed is on the order of 1000. Data acquisition from the noses are generally automatic and built in. The gas generation equipment consists of a Miller-Nelson (MN) flowhemperaturehumidity controller and a Kin-Tek (KT) trace gas generator. This equipment has been controlled in the past by an old data acquisition and control system. The new system will use new control boards and an easy graphical user interface. The programming for this is in the LabVIEW G programming language. A language easy for the user to make modifications to. connections. It is not a primer on LabVIEW programming, a separate CD is being delivered with website files to teach that. This paper details some of the issues in selecting the components and programming the ' Kin-Tek labs Operating Instructions

International Journal of High Speed Electronics and Systems, 2007

Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a ... more Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a bio-aerosol collector or from an environmental water source, into a volume of 1 to 2 ml. is achieved by a liquid flow system including a reversible filter through which filtered liquid can be recirculated or disposed of and from which a concentrated sample is recovered by opening a solenoid valve leading to a detector or to a collection container and reversing the pump for a short time. The reversing action flushes the collected particles off the filter and into the detector or container. The effectiveness of this approach was demonstrated by measuring the cumulative fluorescence of 1-micron-size blue fluorescent microspheres versus cumulative volume withdrawn from our WEP collector after capture from an aerosol suspension of about 140 particles/ml drawn from a test chamber over a 5-minute period at a sampling rate of 500 liters/minute. As the liquid was being withdrawn from the WEP coll...

WORLD SCIENTIFIC eBooks, Dec 1, 2008

Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a ... more Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a bio-aerosol collector or from an environmental water source, into a volume of 1 to 2 ml. is achieved by a liquid flow system including a reversible filter through which filtered liquid can be recirculated or disposed of and from which a concentrated sample is recovered by opening a solenoid valve leading to a detector or to a collection container and reversing the pump for a short time. The reversing action flushes the collected particles off the filter and into the detector or container. The effectiveness of this approach was demonstrated by measuring the cumulative fluorescence of 1-micron-size blue fluorescent microspheres versus cumulative volume withdrawn from our WEP collector after capture from an aerosol suspension of about 140 particles/ml drawn from a test chamber over a 5-minute period at a sampling rate of 500 liters/minute. As the liquid was being withdrawn from the WEP collector, it was filtered at a rate of 1 ml/second and the filter back-flushed with small portions of filtrate at 1-minute intervals. The relative cumulative concentration of captured particles in the first back-flushed 1-ml fraction was around 56 as compared with a value of 1.4 in the first 60-ml filtered fraction, which constitutes a liquid-to-liquid concentration enhancement by a factor of 40 and an air-to-liquid concentration factor of >1.25 × 106.

The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained.

The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained. Much w... more The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained. Much work was performed on the Kamina as it has the ability to respond to low (less than 10 ppb) concentrations ofhydrazine compounds. We were able to tell the difference between Hydrazine (Hz) and Monomethylhydrazine (MMH) in standard clean humid air. We were able to detect MMH in reduced pressure (1/3 atm) at about 250 ppb, however the training set was to far from the real situation to be useful now. Various engineering and usability aspects of both the noses was noted, especially the software. One serious physical engineering flaw was remedied in the Kamina system. A gas flow manifold was created for the Sam system. Different chips were evaluated for the Kamina system. It is still unclear if they can be exchanged without retraining the software. 171 https://ntrs.nasa.gov/search.jsp?R=20020050543 2019-11-16T15:11:52+00:00Z

The electronic nose is a method of using several sensors in conjunction to identify an unknown ga... more The electronic nose is a method of using several sensors in conjunction to identify an unknown gas. Statistical analysis has shown that a large number of training exposures need to be performed in order to get a model that can be depended on. The number of training exposures needed is on the order of 1000. Data acquisition from the noses are generally automatic and built in. The gas generation equipment consists of a Miller-Nelson (MN) flowhemperaturehumidity controller and a Kin-Tek (KT) trace gas generator. This equipment has been controlled in the past by an old data acquisition and control system. The new system will use new control boards and an easy graphical user interface. The programming for this is in the LabVIEW G programming language. A language easy for the user to make modifications to. connections. It is not a primer on LabVIEW programming, a separate CD is being delivered with website files to teach that. This paper details some of the issues in selecting the components and programming the ' Kin-Tek labs Operating Instructions

International Journal of High Speed Electronics and Systems, 2007

Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a ... more Concentration of 1-micron-size micro-organisms from about 100 ml of liquid, whether drawn from a bio-aerosol collector or from an environmental water source, into a volume of 1 to 2 ml. is achieved by a liquid flow system including a reversible filter through which filtered liquid can be recirculated or disposed of and from which a concentrated sample is recovered by opening a solenoid valve leading to a detector or to a collection container and reversing the pump for a short time. The reversing action flushes the collected particles off the filter and into the detector or container. The effectiveness of this approach was demonstrated by measuring the cumulative fluorescence of 1-micron-size blue fluorescent microspheres versus cumulative volume withdrawn from our WEP collector after capture from an aerosol suspension of about 140 particles/ml drawn from a test chamber over a 5-minute period at a sampling rate of 500 liters/minute. As the liquid was being withdrawn from the WEP coll...