The Experts below are selected from a list of 67506 Experts worldwide ranked by ideXlab platform
Andrey S Kudryavtsev - One of the best experts on this subject based on the ideXlab platform.
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the method for on site determination of trace concentrations of methyl mercaptan and dimethyl sulfide in air using a mobile mass spectrometer with atmospheric pressure chemical ionization combined with a fast enrichment separation system
Talanta, 2014Co-Authors: Andrey S Kudryavtsev, Alexey L Makas, M L Troshkov, Mikhail а Grachev, Sergey P PodyachevAbstract:A method for fast simultaneous on-site determination of methyl mercaptan and dimethyl sulfide in air was developed. The target compounds were actively collected on silica gel, followed by direct flash thermal desorption, fast separation on a short chromatographic column and detection by means of mass spectrometer with atmospheric pressure chemical ionization. During the sampling of ambient air, water vapor was removed with a Nafion selective membrane. A compact mass spectrometer prototype, which was designed earlier at Trofimuk Institute of Petroleum Geology and Geophysics, was used. The minimization of gas load of the atmospheric pressure ion source allowed reducing the power requirements and size of the vacuum system and increasing its ruggedness. The Measurement Cycle is about 3 min. Detection limits in a 0.6 L sample are 1 ppb for methyl mercaptan and 0.2 ppb for dimethyl sulfide.
Alfredo Morales-sánchez - One of the best experts on this subject based on the ideXlab platform.
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Analysis of the conduction mechanisms responsible for multilevel bipolar resistive switching of SiO2/Si multilayer structures
Superlattices and Microstructures, 2020Co-Authors: K.e. González-flores, Paul P. Horley, S.a. Cabañas-tay, S.a. Pérez-garcía, L. Licea-jiménez, L. Palacios-huerta, M. Aceves-mijares, M. Moreno-moreno, Alfredo Morales-sánchezAbstract:Abstract We report on the bipolar resistive switching behavior of a SiO2/Si multilayer (ML) structure measured without current compliance for non-volatile memory applications. The SiO2/Si ML structure was thermally annealed to induce the formation of Si nanocrystals, which act as conductive nodes. It was found that the SET/RESET voltages and the ON/OFF resistance ratio (107-102) depend on the current-voltage Measurement Cycles. Moreover, the low resistance state from the initial Cycle can be recovered by increasing the stop voltage in a subsequent Cycle. The space charge limited conduction (SCLC) is the mechanism responsible for the charge transport in the high resistance state (HRS) during the first Measurement Cycle, while the Ohmic conduction predominates in the low resistance state (LRS). This suggest the formation of a conductive path within the SiO2/Si ML, which breaks apart and becomes reconstructed upon switching between the LRS to HRS and vice versa. Performing a sequence of switching Cycles, one can observe that the SCLC becomes predominant for the both LRS and HRS, suggesting the partial formation and breakdown of several different conductive paths.
Pawel Ligeza - One of the best experts on this subject based on the ideXlab platform.
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optimization of single sensor two state hot wire anemometer transmission bandwidth
Sensors, 2008Co-Authors: Pawel LigezaAbstract:Hot-wire anemometric Measurements of non-isothermal flows require the use of thermal compensation or correction circuitry. One possible solution is a two-state hot-wire anemometer that uses the cyclically changing heating level of a single sensor. The area in which flow velocity and fluid temperature can be measured is limited by the dimensions of the sensor's active element. The system is designed to measure flows characterized by high velocity and temperature gradients, although its transmission bandwidth is very limited. In this study, we propose a method to optimize the two-state hot-wire anemometer transmission bandwidth. The method is based on the use of a specialized constant-temperature system together with variable dynamic parameters. It is also based on a suitable Measurement Cycle paradigm. Analysis of the method was undertaken using model testing. Our results reveal a possible significant broadening of the two-state hot-wire anemometer's transmission bandwidth.
Arthur C. Gossard - One of the best experts on this subject based on the ideXlab platform.
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Rapid single-shot Measurement of a singlet-triplet qubit.
Physical review letters, 2009Co-Authors: Christian Barthel, David J. Reilly, Charles Marcus, Micah Hanson, Arthur C. GossardAbstract:We report repeated single-shot Measurements of the two-electron spin state in a GaAs double quantum dot. The readout allows Measurement with a fidelity above 90% with a approximately 7 micros Cycle time. Hyperfine-induced precession between singlet and triplet states of the two-electron system are directly observed, as nuclear Overhauser fields are quasistatic on the time scale of the Measurement Cycle. Repeated Measurements on millisecond to second time scales reveal the evolution of the nuclear environment.
Sergey P Podyachev - One of the best experts on this subject based on the ideXlab platform.
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the method for on site determination of trace concentrations of methyl mercaptan and dimethyl sulfide in air using a mobile mass spectrometer with atmospheric pressure chemical ionization combined with a fast enrichment separation system
Talanta, 2014Co-Authors: Andrey S Kudryavtsev, Alexey L Makas, M L Troshkov, Mikhail а Grachev, Sergey P PodyachevAbstract:A method for fast simultaneous on-site determination of methyl mercaptan and dimethyl sulfide in air was developed. The target compounds were actively collected on silica gel, followed by direct flash thermal desorption, fast separation on a short chromatographic column and detection by means of mass spectrometer with atmospheric pressure chemical ionization. During the sampling of ambient air, water vapor was removed with a Nafion selective membrane. A compact mass spectrometer prototype, which was designed earlier at Trofimuk Institute of Petroleum Geology and Geophysics, was used. The minimization of gas load of the atmospheric pressure ion source allowed reducing the power requirements and size of the vacuum system and increasing its ruggedness. The Measurement Cycle is about 3 min. Detection limits in a 0.6 L sample are 1 ppb for methyl mercaptan and 0.2 ppb for dimethyl sulfide.