A heat flux sensor comprising at least one support, where at least one membrane is suspended relative to the support by at least four nanowires, where the membrane is made from at least one current-conducting material, and where the nanowires are made from a current-conducting material, with two nanowires connected to a current source to polarize the membrane between two terminals and a heater for heating the membrane, and where two nanowires are connected to a voltmeter to form measure the voltage at the terminals of the membrane.

A heat flux sensor comprising at least one support, where at least one membrane is suspended relative to the support by at least four nanowires, where the membrane is made from at least one current-conducting material, and where the nanowires are made from a current-conducting material, with two nanowires connected to a current source to polarize the membrane between two terminals and a heater for heating the membrane, and where two nanowires are connected to a voltmeter to form measure the voltage at the terminals of the membrane.

Systems and methods for monitoring emissions of a combusted gas are provided. The method includes determining a first net heating value of a flare gas. The method also includes determining a second net heating value of a combustion gas including the flare gas. The second net heating value can be determined based upon the first net heating value and a volumetric flow rate of the flare gas. Based upon the value of the second net heating value, an empirical model or a non-parametric machine learning model can be selected. A combustion efficiency of the combustion gas can be determined using the selected model, the second net heating value, and selected ones of the process conditions and the environmental conditions. Total emissions of the combustion mixture can be further determined from the combustion efficiency and a volumetric flow rate of the combustion gas.

The present application is directed to a method of measuring the concentration of radicals in a gas stream which includes the steps of flowing a radical gas stream emitted from at least one radical gas generator to at least one processing chamber, providing at least one sampling reaction module having at least one sampling tube therein, establishing a reference temperature of the sampling tube with at least one thermal control module, diverting a portion of the radical gas steam from the radical gas generator into the sampling tube, reacting at least one reagent with at least one radical gas within a defined volume of the radical gas stream thereby forming at least one chemical species within at least one compound stream, the compound stream flowing within the sampling tube, measuring a change of temperature of the sampling tube due to interaction of the chemical species within the compound stream and the sampling tube with sensor module, and calculating a concentration of the chemical species within the compound stream flowing within the sampling tube based on the measured temperature change of the sampling tube.

The present application is directed to a method of measuring the concentration of radicals in a gas stream which includes the steps of flowing a radical gas stream emitted from at least one radical gas generator to at least one processing chamber, providing at least one sampling reaction module having at least one sampling tube therein, establishing a reference temperature of the sampling tube with at least one thermal control module, diverting a portion of the radical gas steam from the radical gas generator into the sampling tube, reacting at least one reagent with at least one radical gas within a defined volume of the radical gas stream thereby forming at least one chemical species within at least one compound stream, the compound stream flowing within the sampling tube, measuring a change of temperature of the sampling tube due to interaction of the chemical species within the compound stream and the sampling tube with sensor module, and calculating a concentration of the chemical species within the compound stream flowing within the sampling tube based on the measured temperature change of the sampling tube.

Ultrasensitive, decoupled thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other known systems, and may be used to detect and identify a single molecule of an analyte.

Ultrasensitive, decoupled thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other known systems, and may be used to detect and identify a single molecule of an analyte.

A vertical fan unit includes a cabinet, a fan unit and a heating and cooling coil. A piping and valve assembly connects the heating and cooling coil to a four-pipe vertical riser. Shut-off ball valves are connected to respective hot and cold supply pipes of the vertical riser out of the path of air flowing through the heating and cooling coil. Hot and cold return valve assemblies include control ball valves connected to respective return pipes of the four pipe vertical riser and positioned adjacent the side wall out of the path of air flowing through the heating and cooling coil. A cable connects each temperature probe of the shut-off ball valves with respective BTU meters mounted at the control ball valves.

A method of controlling cooling water treatment may involve measuring operating data of one or more downstream heat exchangers that receive cooling water from the cooling tower. For example, the inlet and outlet temperatures of both the hot and cold streams of a downstream heat exchanger may be measured. Data from the streams passing through the heat exchanger may be used to determine a heat transfer efficiency for the heat exchanger. The heat transfer efficiency can be trended over a period of time and changes in the trend detected to identify cooling water fouling issues. Multiple potential causes of the perceived fouling issues can be evaluated to determine a predicted cause. A chemical additive selected to reduce, eliminate, or otherwise control the cooling water fouling can be controlled based on the predicted cause of the fouling.

A method of controlling cooling water treatment may involve measuring operating data of one or more downstream heat exchangers that receive cooling water from the cooling tower. For example, the inlet and outlet temperatures of both the hot and cold streams of a downstream heat exchanger may be measured. Data from the streams passing through the heat exchanger may be used to determine a heat transfer efficiency for the heat exchanger. The heat transfer efficiency can be trended over a period of time and changes in the trend detected to identify cooling water fouling issues. Multiple potential causes of the perceived fouling issues can be evaluated to determine a predicted cause. A chemical additive selected to reduce, eliminate, or otherwise control the cooling water fouling can be controlled based on the predicted cause of the fouling.