The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
T Sitaramanjaneya Mouli - One of the best experts on this subject based on the ideXlab platform.
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Assembly, formation mechanism, and enhanced gas-sensing properties of porous and hierarchical SnO2 hollow nanostructures
Journal of Materials Research, 2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Jinhuai Liu, Yu Zhong, Guangyu Chen, Kai Qian, T Sitaramanjaneya MouliAbstract:Hierarchical and hollow SnS2 nanostructures as Precursors were fabricated via a surfactant-assisted assembly process using sodium dodecyl sulfate as soft templates. The as-prepared SnS2 nanostructures were further oxidized to form porous SnO2 conversion for investigating their gas-sensing properties in Drug-precursor detection. On the basis of a series of time- and ratio-dependent reactions, a formation mechanism of the special nanostructures and factors influencing morphology and structure were determined. Gas-sensing measurements revealed that the porous and hierarchical SnO2 hollow nanostructures were sensitive to Drug Precursors, indicating promising applications in environmental monitoring and public safety investigation. In addition, we found that the assembled SnO2 nanomaterials possessed significantly enhanced gas-sensing properties compared with unassembled SnO2 with a solid interior.
Jinyun Liu - One of the best experts on this subject based on the ideXlab platform.
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Comparison on gas-sensing properties of single- and multi-layered SnO2 nanostructures in Drug-Precursors detection
Procedia Engineering, 2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Zhen Jin, Lingtao Kong, Jinhuai LiuAbstract:AbstractSystematic comparison on gas-sensing properties of single- and multi-layered SnO2 nanomaterials in Drug-Precursors detection from the aspects of gas-sensing response and kinetic adsorption/desorption process was presented for the first time. The SnO2 nanomaterials with single- and multi-layered structures assembled by numerous nanoparticles were prepared via a hydrothermal route using carbonaceous spheres as templates. In gas-sensing measurements, Drug-Precursors including aether and chloroform were employed as targets. The gas-sensing responses towards target gases at a series of concentrations were investigated. The results show that the gas sensor based on multi-layered SnO2 nanoarchitectures exhibits higher sensitivities compared with those of the single-layered ones. However, the response and recovery times are longer than the later one, indicating a lower diffusion speed during the surface contact reactions. The mechanism for the different gas-sensing performance of single- and multi-layered SnO2 nanomaterials was further demonstrated from the kinetic processes of gas adsorption/desorption. Our findings shed a light for the design of novel nanoparticle-assembled architectures for applications based on surface contact reactions such as security monitoring and environmental sensors
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2010 symposium on security detection and information processing comparison on gas sensing properties of single and multi layered sno2 nanostructures in Drug Precursors detection
2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Zhen Jin, Lingtao Kong, Jinhuai LiuAbstract:Systematic comparison on gas-sensing properties of single- and multi-layered SnO2 nanomaterials in Drug-Precursors detection from the aspects of gas-sensing response and kinetic adsorption/desorption process was presented for the first time. The SnO2 nanomaterials with single- and multi-layered structures assembled by numerous nanoparticles were prepared via a hydrothermal route using carbonaceous spheres as templates. In gas-sensing measurements, Drug-Precursors including aether and chloroform were employed as targets. The gas-sensing responses towards target gases at a series of concentrations were investigated. The results show that the gas sensor based on multi-layered SnO2 nanoarchitectures exhibits higher sensitivities compared with those of the single-layered ones. However, the response and recovery times are longer than the later one, indicating a lower diffusion speed during the surface contact reactions. The mechanism for the different gas-sensing performance of single- and multi-layered SnO2 nanomaterials was further demonstrated from the kinetic processes of gas adsorption/desorption. Our findings shed a light for the design of novel nanoparticle-assembled architectures for applications based on surface contact reactions such as security monitoring and environmental sensors.
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Assembly, formation mechanism, and enhanced gas-sensing properties of porous and hierarchical SnO2 hollow nanostructures
Journal of Materials Research, 2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Jinhuai Liu, Yu Zhong, Guangyu Chen, Kai Qian, T Sitaramanjaneya MouliAbstract:Hierarchical and hollow SnS2 nanostructures as Precursors were fabricated via a surfactant-assisted assembly process using sodium dodecyl sulfate as soft templates. The as-prepared SnS2 nanostructures were further oxidized to form porous SnO2 conversion for investigating their gas-sensing properties in Drug-precursor detection. On the basis of a series of time- and ratio-dependent reactions, a formation mechanism of the special nanostructures and factors influencing morphology and structure were determined. Gas-sensing measurements revealed that the porous and hierarchical SnO2 hollow nanostructures were sensitive to Drug Precursors, indicating promising applications in environmental monitoring and public safety investigation. In addition, we found that the assembled SnO2 nanomaterials possessed significantly enhanced gas-sensing properties compared with unassembled SnO2 with a solid interior.
Renato Seeber - One of the best experts on this subject based on the ideXlab platform.
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Simulation of an experimental database of infrared spectra of complex gaseous mixtures for detecting specific substances. The case of Drug Precursors
Sensors and Actuators B: Chemical, 2014Co-Authors: Marco Calderisi, Alessandro Ulrici, Sauli Sinisalo, Juho Uotila, Renato SeeberAbstract:Abstract This work is motivated by the need to develop suitable databases in absence of real experimental data, for instance when spectra measured with a newly developed instrumentation on real samples are not available yet. This notwithstanding, in fact, the realization of the physical project should be addressed by a starting database, also invaluable in order to test its effectiveness. In this article we face the issue of simulating gas mixtures spectra for the development of a new sensor for external cavity-quantum cascade laser photoacoustic spectroscopy (EC-QCLPAS) starting from literature FT-IR spectra of pure components: a dataset is realized suitable to realistically represent the ensemble of spectra of the gas mixtures of interest. The informative data deriving from the literature spectra were combined with the stochastic component extracted from a sample spectrum recorded with a prototype instrument, allowing us to build a matrix containing thousands of simulated spectra of gaseous mixtures, accounting for the presence of different components at different concentrations. Signal processing and experimental design techniques were used along the whole path leading to the dataset of simulated spectra. In particular, the goal of the construction of the database lies in the development of a final system to detect Drug Precursors in the vapor phase. The comparison of some EC-QCLPAS spectra with the corresponding simulated signals confirms the validity of the proposed approach.
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Toward a compact instrument for detecting Drug Precursors in different environments
Lecture Notes in Electrical Engineering, 2013Co-Authors: Fabio Terzi, Alberto Secchi, Antonio Varriale, Alessandro Ulrici, Renato Seeber, Anna Maria Fiorello, M. Dispenza, J. C. Antolín, Tom Kuusela, Sabato D'auriaAbstract:Law enforcement agencies world-wide are keenly aware that chemical control is a crucial element to monitor the manufacture and distribution of illegal narcotics and synthetic substances. For this purpose components able to perform chemical identifications in contexts such as custom offices are needed, where inspection of trucks, cars, containers, as well as people and baggage, is required.
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Experimental design-based strategy for the simulation of complex gaseous mixture spectra to detect Drug Precursors
Optical Materials and Biomaterials in Security and Defence Systems Technology IX, 2012Co-Authors: Marco Calderisi, Alberto Secchi, Alessandro Ulrici, Laura Pigani, Renato SeeberAbstract:The EU FP7 project CUSTOM (Drugs and Precursor Sensing by Complementing Low Cost Multiple Techniques) aims at developing a new sensing system for the detection of Drug Precursors in gaseous samples, which includes an External Cavity-Quantum Cascade Laser Photo-Acoustic Sensor (EC-QCLPAS) that is in the final step of realisation. Thus, a simulation based on FT-IR literature spectra has been accomplished, where the development of a proper strategy for the design of the composition of the environment, as much as possible realistic and representative of different scenarios, is of key importance. To this aim, an approach based on the combination of signal processing and experimental design techniques has been developed. The gaseous mixtures were built by adding the considered 4 Drug precursor (target) species to the gases typically found in atmosphere, taking also into account possible interfering species. These last chemicals were selected considering custom environments (20 interfering chemical species), whose concentrations have been inferred from literature data. The spectra were first denoised by means of a Fast Wavelet Transform-based algorithm; then, a procedure based on a sigmoidal transfer function was developed to multiply the pure components spectra by the respective concentration values, in a way to correctly preserve background intensity and shape, and to operate only on the absorption bands. The noise structure of the EC-QCLPAS was studied using sample spectra measured with a prototype instrument, and added to the simulated mixtures. Finally a matrix containing 5000 simulated spectra of gaseous mixtures was built up.
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Drugs and precursor sensing by complementing low cost multiple techniques: overview of the European FP7 project CUSTOM
Optical Materials and Biomaterials in Security and Defence Systems Technology IX, 2012Co-Authors: Alberto Secchi, Antonio Varriale, Sabato D'auria, Alessandro Ulrici, Renato Seeber, Juho Uotila, Anna Maria Fiorello, M. Dispenza, Vincenzo Venditto, Paolo CiambelliAbstract:A large number of techniques for Drug Precursors chemical sensing has been developed in the latest decades. These techniques are able to screen and identify specific molecules even at very low concentration in lab environment, nevertheless the objective to build up a system which proves to be easy to use, compact, able to provide screening over a large number of compounds and discriminate them with low false alarm rate (FA) and high probability of detection (POD) is still an open issue. The project CUSTOM, funded by the European Commission within the FP7, deals with stand alone portable sensing apparatus based on multiple techniques, integrated in a complex system with a complimentary approach. The objective of the project is to achieve an optimum trade-off between opposite requirements: compactness, simplicity, low cost, sensitivity, low false alarm rate and selectivity. The final goal is the realization of an optical sensing platform able to detect traces of Drug Precursors compounds, such as ephedrine, safrole, acetic anhydride and the Benzyl Methyl Keton (BMK). This is reached by implementing two main sensing techniques: the fluorescence enhanced by the use of specially developed Organic macro-molecules, and a spectroscopic technique in Mid-IR optical range. The fluorescence is highly selectivewith respect to the target compounds, because it is based on properly engineered fluorescent proteins which are able to bind the target analytes, as it happens in an 'immune-type' reaction. The spectroscopic technique is based on the Photo-Acoustic effect, enhanced by the use of a widely Tunable Quantum Cascade Laser. Finally, the sensing platform is equipped with an air sampling system including a pre-concentrator module based on a sorption desorption cycles of a syndiotactic polystyrene polymer.
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A feature selection strategy for the analysis of spectra from a photoacoustic sensing system
Optical Materials and Biomaterials in Security and Defence Systems Technology IX, 2012Co-Authors: Alessandro Ulrici, Marco Calderisi, Renato Seeber, Juho Uotila, Giorgia Foca, Mathieu Carras, Anna Maria FiorelloAbstract:In the frame of the EU project CUSTOM, a new sensor system for the detection of Drug Precursors in gaseous samples is being developed, which also includes an External Cavity-Quantum Cascade Laser Photo Acoustic Sensor (ECQCLPAS). In order to define the characteristics of the laser source, the optimal wavenumbers within the most effective 200 cm -1 range in the mid-infrared region must be identified, in order to lead to optimal detection of the Drug precursor molecules in presence of interfering species and of variable composition of the surrounding atmosphere. To this aim, based on simulations made with FT-IR spectra taken from literature, a complex multivariate analysis strategy has been developed to select the optimal wavenumbers. Firstly, the synergistic use of Experimental Design and of Signal Processing techniques led to a dataset of 5000 simulated spectra of mixtures of 33 different gases (including the 4 target molecules). After a preselection, devoted to disregard noisy regions due to small interfering molecules, the simulated mixtures were then used to select the optimal wavenumber range, by maximizing the classification efficiency, as estimated by Partial Least Squares - Discriminant Analysis. A moving window 200 cm -1 wide was used for this purpose. Finally, the optimal wavenumber values were identified within the selected range, using a feature selection approach based on Genetic Algorithms and on resampling. The work made will be relatively easily turned to the spectra actually recorded with the newly developed EC-QCLPAS instrument. Furthermore, the proposed approach allows progressive adaptation of the spectral dataset to real situations, even accounting for specific, different environments
Jinhuai Liu - One of the best experts on this subject based on the ideXlab platform.
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Comparison on gas-sensing properties of single- and multi-layered SnO2 nanostructures in Drug-Precursors detection
Procedia Engineering, 2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Zhen Jin, Lingtao Kong, Jinhuai LiuAbstract:AbstractSystematic comparison on gas-sensing properties of single- and multi-layered SnO2 nanomaterials in Drug-Precursors detection from the aspects of gas-sensing response and kinetic adsorption/desorption process was presented for the first time. The SnO2 nanomaterials with single- and multi-layered structures assembled by numerous nanoparticles were prepared via a hydrothermal route using carbonaceous spheres as templates. In gas-sensing measurements, Drug-Precursors including aether and chloroform were employed as targets. The gas-sensing responses towards target gases at a series of concentrations were investigated. The results show that the gas sensor based on multi-layered SnO2 nanoarchitectures exhibits higher sensitivities compared with those of the single-layered ones. However, the response and recovery times are longer than the later one, indicating a lower diffusion speed during the surface contact reactions. The mechanism for the different gas-sensing performance of single- and multi-layered SnO2 nanomaterials was further demonstrated from the kinetic processes of gas adsorption/desorption. Our findings shed a light for the design of novel nanoparticle-assembled architectures for applications based on surface contact reactions such as security monitoring and environmental sensors
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2010 symposium on security detection and information processing comparison on gas sensing properties of single and multi layered sno2 nanostructures in Drug Precursors detection
2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Zhen Jin, Lingtao Kong, Jinhuai LiuAbstract:Systematic comparison on gas-sensing properties of single- and multi-layered SnO2 nanomaterials in Drug-Precursors detection from the aspects of gas-sensing response and kinetic adsorption/desorption process was presented for the first time. The SnO2 nanomaterials with single- and multi-layered structures assembled by numerous nanoparticles were prepared via a hydrothermal route using carbonaceous spheres as templates. In gas-sensing measurements, Drug-Precursors including aether and chloroform were employed as targets. The gas-sensing responses towards target gases at a series of concentrations were investigated. The results show that the gas sensor based on multi-layered SnO2 nanoarchitectures exhibits higher sensitivities compared with those of the single-layered ones. However, the response and recovery times are longer than the later one, indicating a lower diffusion speed during the surface contact reactions. The mechanism for the different gas-sensing performance of single- and multi-layered SnO2 nanomaterials was further demonstrated from the kinetic processes of gas adsorption/desorption. Our findings shed a light for the design of novel nanoparticle-assembled architectures for applications based on surface contact reactions such as security monitoring and environmental sensors.
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Assembly, formation mechanism, and enhanced gas-sensing properties of porous and hierarchical SnO2 hollow nanostructures
Journal of Materials Research, 2010Co-Authors: Jinyun Liu, Yuteng Wan, Fanli Meng, Jinhuai Liu, Yu Zhong, Guangyu Chen, Kai Qian, T Sitaramanjaneya MouliAbstract:Hierarchical and hollow SnS2 nanostructures as Precursors were fabricated via a surfactant-assisted assembly process using sodium dodecyl sulfate as soft templates. The as-prepared SnS2 nanostructures were further oxidized to form porous SnO2 conversion for investigating their gas-sensing properties in Drug-precursor detection. On the basis of a series of time- and ratio-dependent reactions, a formation mechanism of the special nanostructures and factors influencing morphology and structure were determined. Gas-sensing measurements revealed that the porous and hierarchical SnO2 hollow nanostructures were sensitive to Drug Precursors, indicating promising applications in environmental monitoring and public safety investigation. In addition, we found that the assembled SnO2 nanomaterials possessed significantly enhanced gas-sensing properties compared with unassembled SnO2 with a solid interior.
N. D. Chkanikov - One of the best experts on this subject based on the ideXlab platform.
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synthesis of new fluorine containing pyrazolo 3 4 b pyridinones as promising Drug Precursors
ChemInform, 2012Co-Authors: A. S. Golubev, G. S. Starostin, K. S. Chunikhin, A. S. Peregudov, K. C. Rodygin, Svetlana A. Rubtsova, Pavel A. Slepukhin, A. V. Kuchin, N. D. ChkanikovAbstract:The approaches to the synthesis of earlier unknown title compounds containing the 4-ArSCF2 and 4-ArSCHF groups involve i) direct annulation of substituted aminopyrazoles (I) with halogenated acetoacetates like (II), (V), and (X), and ii) replacement of the Br atom of the 4-CF2Br group, or the Cl atom of the 4-CHFCl group by sodium arenethiolates (VII) and (XII).
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Synthesis of New Fluorine‐Containing Pyrazolo[3,4‐b]pyridinones as Promising Drug Precursors.
ChemInform, 2012Co-Authors: A. S. Golubev, G. S. Starostin, K. S. Chunikhin, A. S. Peregudov, K. C. Rodygin, Svetlana A. Rubtsova, Pavel A. Slepukhin, A. V. Kuchin, N. D. ChkanikovAbstract:The approaches to the synthesis of earlier unknown title compounds containing the 4-ArSCF2 and 4-ArSCHF groups involve i) direct annulation of substituted aminopyrazoles (I) with halogenated acetoacetates like (II), (V), and (X), and ii) replacement of the Br atom of the 4-CF2Br group, or the Cl atom of the 4-CHFCl group by sodium arenethiolates (VII) and (XII).
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Synthesis of new fluorine-containing pyrazolo[3,4-b]pyridinones as promising Drug Precursors
Russian Chemical Bulletin, 2011Co-Authors: A. S. Golubev, G. S. Starostin, K. S. Chunikhin, A. S. Peregudov, K. C. Rodygin, Svetlana A. Rubtsova, Pavel A. Slepukhin, A. V. Kuchin, N. D. ChkanikovAbstract:Methods for the synthesis of 4-R-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones (R = CF2SAr and 4-CFHSAr) were developed. The derivatives with R = CF2SAr were obtained by both heterocyclization of 1-substituted 5-aminopyrazoles with ethyl 4,4-difluoro-3-oxo-4-phenylsulfanylbutanoate and replacement of the Br atom in 4-bromodifluoromethyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones by sodium arenethiolates. The fragment 4-CF-HSAr was introduced by replacement of the Cl atom in 4-chlorofluoromethyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones by sodium arenethiolates. Oxidation of 4-CF2SPh-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones gave the corresponding sulfoxides; their structures were confirmed by X-ray diffraction data.
