Abstract: A surface-enhanced Raman scattering (SERS) substrate is provided. The SERS substrate includes a transparent substrate and a nanocomposite composition. The nanocomposite composition includes a silver-loaded silica (Ag—SiO2) nanocomposite having a silica core and a silver/silica shell disposed around the silica core and a zeolitic material having a nano porous structure. The silver/silica shell contains silver nanoparticles uniformly distributed therein. The Ag—SiO2 nanocomposite is uniformly disposed on a surface of the zeolitic material. The nanoparticles of the Ag—SiO2 nanocomposite are spherical and have a mean particle size of 100 to 500 nanometers (nm). A method of obtaining a Raman spectrum of a sulfur-containing compound in a mixing composition is also provided.

Abstract: A method of detecting an hydroxycarbamide in a solution including contacting an electrochemical sensor with the solution, where the electrochemical sensor includes gold coated copper oxide circular nanoplates and a substrate. The gold coated copper oxide circular nanoplates are coated on the substrate. The method further includes applying a potential and irradiating the electrochemical sensor in the solution, and measuring a Raman signal of the electrochemical sensor in the solution. The intensity of the Raman signal correlates with the amount of hydroxycarbamide in the solution.

Abstract: A surface-enhanced Raman scattering (SERS) substrate is provided. The SERS substrate includes a transparent substrate and a nanocomposite composition. The nanocomposite composition includes a silver-loaded silica (Ag—SiO2) nanocomposite having a silica core and a silver/silica shell disposed around the silica core and a zeolitic material having a nano porous structure. The silver/silica shell contains silver nanoparticles uniformly distributed therein. The Ag—SiO2 nanocomposite is uniformly disposed on a surface of the zeolitic material. The nanoparticles of the Ag—SiO2 nanocomposite are spherical and have a mean particle size of 100 to 500 nanometers (nm). A method of obtaining a Raman spectrum of a sulfur-containing compound in a mixing composition is also provided.

Abstract: A surface-enhanced Raman scattering (SERS) substrate is provided. The SERS substrate includes a transparent substrate and a nanocomposite composition. The nanocomposite composition includes a silver-loaded silica (Ag—SiO2) nanocomposite having a silica core and a silver/silica shell disposed around the silica core and a zeolitic material having a nano porous structure. The silver/silica shell contains silver nanoparticles uniformly distributed therein. The Ag—SiO2 nanocomposite is uniformly disposed on a surface of the zeolitic material. The nanoparticles of the Ag—SiO2 nanocomposite are spherical and have a mean particle size of 100 to 500 nanometers (nm). A method of obtaining a Raman spectrum of a sulfur-containing compound in a mixing composition is also provided.

Abstract: A method of detecting an hydroxycarbamide in a solution including contacting an electrochemical sensor with the solution, where the electrochemical sensor includes gold coated copper oxide circular nanoplates and a substrate. The gold coated copper oxide circular nanoplates are coated on the substrate. The method further includes applying a potential and irradiating the electrochemical sensor in the solution, and measuring a Raman signal of the electrochemical sensor in the solution. The intensity of the Raman signal correlates with the amount of hydroxycarbamide in the solution.

Abstract: A surface-enhanced Raman scattering (SERS) substrate is provided. The SERS substrate includes a transparent substrate and a nanocomposite composition. The nanocomposite composition includes a silver-loaded silica (Ag—SiO2) nanocomposite having a silica core and a silver/silica shell disposed around the silica core and a zeolitic material having a nano porous structure. The silver/silica shell contains silver nanoparticles uniformly distributed therein. The Ag—SiO2 nanocomposite is uniformly disposed on a surface of the zeolitic material. The nanoparticles of the Ag—SiO2 nanocomposite are spherical and have a mean particle size of 100 to 500 nanometers (nm). A method of obtaining a Raman spectrum of a sulfur-containing compound in a mixing composition is also provided.

Abstract: The present invention includes a method and system using dynamic pressure measurements for determining a presence, location, and size of a leak in a chamber of a body. The method includes sealing a plurality of ports of the chamber, pressurizing the chamber with a fluid, measuring a dynamic pressure at each of the plurality of ports, and analyzing the dynamic pressure measured at each of the plurality of ports to determine a presence, location, and/or size of the leak. The location of the leak can be determined by analyzing magnitude and/or phase values from a generated frequency response function matrix, interpolating between two of the plurality of ports, triangulating between three of the plurality of ports, and/or analyzing a rate and profile at which the pressure decays at each of the plurality of ports to determine the location of the leak.