The Experts below are selected from a list of 120933 Experts worldwide ranked by ideXlab platform
Amrik S Walia - One of the best experts on this subject based on the ideXlab platform.
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improved gas chromatography mass spectrometry analysis of barbiturates in urine using centrifuge based solid phase extraction methylation with d5 pentobarbital as internal standard
Journal of Forensic Sciences, 1994Co-Authors: Angela M Mckeehan, Cinnamon Edwards, Garon Foster, Wayne D Bensley, Jeffrey G Langner, Amrik S WaliaAbstract:Effective solid-phase extraction, derivatization, and GC/MS procedures are developed for the simultaneous determinations of butalbital, amobarbital, pentobarbital, and secobarbital, using a deuterated pentobarbital (ds-pentobarbital) as the internal standard. Buffered (pH 7) urine samples were extracted with Bond Elute Certify II TM cartridge. Iodomethane/ tetramethylammonium hydroxide in dimethylsulfoxide was used for methylation, while a HP 5970 MSD equipped with a 13 m J & W DB-5 column (5% phenyl polysiloxane phase) and the Thru-Put Target | Software package were used for GC/MS analysis and data processing. This protocol was found to be superior, in both chromatographic performance characteristics and quantitation results, over a liquid-liquid extraction procedure without derivatization using hexobarbital as the internal standard. Extraction recoveries observed from control samples containing four barbiturates range from 80% to 90%. Good one-point calibration data are obtained for all four barbiturates in the 50 to 3200 n~mL range. Interestingly, the one-point calibration data for pentobarbital are inferior to the other three barbiturates~ue to interference from the internal standard (ds-pentobarbital). The calibration data of pentobarbital are best described by a hyperbolic curve regression model. Precision data (% CV) for GC/MS analysis, over-all procedure, and day-to-day performance are approximately 2.0%, 6.0%, and 8.0%, respectively. With the use of a 2 mL sample size, the attainable detection limit is approximately 20 ng/mL.
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enzymatic digestion solid phase extraction and gas chromatography mass spectrometry of derivatized intact oxazepam in urine
Clinical Chemistry, 1991Co-Authors: Jeffrey G Langner, Cinnamon Edwards, B K Gan, R H Liu, L D Baugh, P Chand, J L Weng, Amrik S WaliaAbstract:Enzymatic digestion with beta-glucuronidase (EC 3.2.1.31) was used to release intact oxazepam from urine samples containing the d5-analog internal standard. The resulting specimens were extracted with Du Pont PREP Type W cartridge (processed by a PREP Automated Sample Processor), Bond Elut Certify, and J.T. Baker "spe" columns for comparison of the columns' extraction recovery and overall effectiveness. Methyl iodide/tetrahexylammonium hydrogen sulfate and N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (10 g/L) were used for the methylation and trimethylsilylation studies. We used a Hewlett-Packard HP 5790 mass-selective detector equipped with a 13-m J & W DB-5 column (5% phenyl polysiloxane phase) for gas chromatography/mass spectroscopy (GC/MS) analysis and the Thru-Put Target Software package for data processing. After several exploratory experiments, we adopted the Du Pont PREP system methylation procedure because of its effective recovery, the superior stability of the derivatization product, the possibility of incorporating a clean-up step, and the potential for high throughput. The extraction recovery from a set of control samples was 87%. Coefficients of variation obtained for six replicates of GC/MS analysis and for the overall procedure were 1% and 3%, respectively. Excellent linearity was established in the 50-8000 micrograms/L concentration range studied. With the use of 3-mL samples, a 20-microL final reconstitution volume, oxazepam at 50 micrograms/L was easily detected under the adopted operation conditions.
Jeffrey G Langner - One of the best experts on this subject based on the ideXlab platform.
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improved gas chromatography mass spectrometry analysis of barbiturates in urine using centrifuge based solid phase extraction methylation with d5 pentobarbital as internal standard
Journal of Forensic Sciences, 1994Co-Authors: Angela M Mckeehan, Cinnamon Edwards, Garon Foster, Wayne D Bensley, Jeffrey G Langner, Amrik S WaliaAbstract:Effective solid-phase extraction, derivatization, and GC/MS procedures are developed for the simultaneous determinations of butalbital, amobarbital, pentobarbital, and secobarbital, using a deuterated pentobarbital (ds-pentobarbital) as the internal standard. Buffered (pH 7) urine samples were extracted with Bond Elute Certify II TM cartridge. Iodomethane/ tetramethylammonium hydroxide in dimethylsulfoxide was used for methylation, while a HP 5970 MSD equipped with a 13 m J & W DB-5 column (5% phenyl polysiloxane phase) and the Thru-Put Target | Software package were used for GC/MS analysis and data processing. This protocol was found to be superior, in both chromatographic performance characteristics and quantitation results, over a liquid-liquid extraction procedure without derivatization using hexobarbital as the internal standard. Extraction recoveries observed from control samples containing four barbiturates range from 80% to 90%. Good one-point calibration data are obtained for all four barbiturates in the 50 to 3200 n~mL range. Interestingly, the one-point calibration data for pentobarbital are inferior to the other three barbiturates~ue to interference from the internal standard (ds-pentobarbital). The calibration data of pentobarbital are best described by a hyperbolic curve regression model. Precision data (% CV) for GC/MS analysis, over-all procedure, and day-to-day performance are approximately 2.0%, 6.0%, and 8.0%, respectively. With the use of a 2 mL sample size, the attainable detection limit is approximately 20 ng/mL.
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enzymatic digestion solid phase extraction and gas chromatography mass spectrometry of derivatized intact oxazepam in urine
Clinical Chemistry, 1991Co-Authors: Jeffrey G Langner, Cinnamon Edwards, B K Gan, R H Liu, L D Baugh, P Chand, J L Weng, Amrik S WaliaAbstract:Enzymatic digestion with beta-glucuronidase (EC 3.2.1.31) was used to release intact oxazepam from urine samples containing the d5-analog internal standard. The resulting specimens were extracted with Du Pont PREP Type W cartridge (processed by a PREP Automated Sample Processor), Bond Elut Certify, and J.T. Baker "spe" columns for comparison of the columns' extraction recovery and overall effectiveness. Methyl iodide/tetrahexylammonium hydrogen sulfate and N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (10 g/L) were used for the methylation and trimethylsilylation studies. We used a Hewlett-Packard HP 5790 mass-selective detector equipped with a 13-m J & W DB-5 column (5% phenyl polysiloxane phase) for gas chromatography/mass spectroscopy (GC/MS) analysis and the Thru-Put Target Software package for data processing. After several exploratory experiments, we adopted the Du Pont PREP system methylation procedure because of its effective recovery, the superior stability of the derivatization product, the possibility of incorporating a clean-up step, and the potential for high throughput. The extraction recovery from a set of control samples was 87%. Coefficients of variation obtained for six replicates of GC/MS analysis and for the overall procedure were 1% and 3%, respectively. Excellent linearity was established in the 50-8000 micrograms/L concentration range studied. With the use of 3-mL samples, a 20-microL final reconstitution volume, oxazepam at 50 micrograms/L was easily detected under the adopted operation conditions.
Armin Moin - One of the best experts on this subject based on the ideXlab platform.
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data analytics and machine learning methods techniques and tool for model driven engineering of smart iot services
International Conference on Software Engineering, 2021Co-Authors: Armin MoinAbstract:This doctoral dissertation proposes a novel approach to enhance the development of smart services for the Internet of Things (IoT) and smart Cyber-Physical Systems (CPS). The proposed approach offers abstraction and automation to the Software engineering processes, as well as the Data Analytics (DA) and Machine Learning (ML) practices. This is realized in an integrated and seamless manner. We implement and validate the proposed approach by extending an open source modeling tool, called ThingML. ThingML is a domain-specific language and modeling tool with code generation for the IoT/CPS domain. Neither ThingML nor any other IoT/CPS modeling tool supports DA/ML at the modeling level. Therefore, as the primary contribution of the doctoral dissertation, we add the necessary syntax and semantics concerning DA/ML methods and techniques to the modeling language of ThingML. Moreover, we support the APIs of several ML libraries and frameworks for the automated generation of the source code of the Target Software in Python and Java. Our approach enables platform-independent, as well as platform-specific models. Further, we assist in carrying out semiautomated DA/ML tasks by offering Automated ML (AutoML), in the background (in expert mode), and through model-checking constraints and hints at design-time. Finally, we consider three use case scenarios from the domains of network security, smart energy systems and energy exchange markets.
Wolfgang Rosenstiel - One of the best experts on this subject based on the ideXlab platform.
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combination of instruction set simulation and abstract rtos model execution for fast and accurate Target Software evaluation
International Conference on Hardware Software Codesign and System Synthesis, 2008Co-Authors: Matthias Krause, Dominik Englert, Oliver Bringmann, Wolfgang RosenstielAbstract:Instruction set simulation and real time operating system modeling have become important issues for the design of distributed embedded systems. This paper presents a holistic approach to simulate a distributed, embedded system that includes Target Software, processing units, and abstract RTOS within a virtual prototype environment. The processing unit is modeled by an ISS, which is embedded in a SystemC environment to allow the integration into a platform model. In comparison to existing approaches, the RTOS is not directly running on the ISS but outsourced and replaced by an RTOS model. This step strongly reduces simulation time since the execution on the ISS is much more time consuming in contrast to the execution on the host processor. The results show the theoretical and measured performance gain depending on the RTOS scheduler and task switching.
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Target Software generation an approach for automatic mapping of systemc specifications onto real time operating systems
Design Automation for Embedded Systems, 2005Co-Authors: Matthias Krause, Oliver Bringmann, Wolfgang RosenstielAbstract:In this paper we present a new approach for automated Target code generation for given real-time operating systems out of SystemC to support platform independent Software development. Since SystemC becomes the most important language in electronic system level design, the support of a seamless design flow becomes an important task. During the system design process, SystemC is used to develop a "Golden Reference Model" that provides a well-suited platform for specification, simulation, and verification of embedded systems. Based on the "Golden Reference Model," an important task of the design process is to map applications, that have been described either in C++ or directly in SystemC, to the specific real-time operating system which is running at the Target processor. Since a manual mapping approach is time-consuming and error-prone, the mapping process should be performed automatically. This paper presents a new method for automated generation of code for a specified operating system just by using an abstract XML representation of the RTOS API.
Cinnamon Edwards - One of the best experts on this subject based on the ideXlab platform.
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improved gas chromatography mass spectrometry analysis of barbiturates in urine using centrifuge based solid phase extraction methylation with d5 pentobarbital as internal standard
Journal of Forensic Sciences, 1994Co-Authors: Angela M Mckeehan, Cinnamon Edwards, Garon Foster, Wayne D Bensley, Jeffrey G Langner, Amrik S WaliaAbstract:Effective solid-phase extraction, derivatization, and GC/MS procedures are developed for the simultaneous determinations of butalbital, amobarbital, pentobarbital, and secobarbital, using a deuterated pentobarbital (ds-pentobarbital) as the internal standard. Buffered (pH 7) urine samples were extracted with Bond Elute Certify II TM cartridge. Iodomethane/ tetramethylammonium hydroxide in dimethylsulfoxide was used for methylation, while a HP 5970 MSD equipped with a 13 m J & W DB-5 column (5% phenyl polysiloxane phase) and the Thru-Put Target | Software package were used for GC/MS analysis and data processing. This protocol was found to be superior, in both chromatographic performance characteristics and quantitation results, over a liquid-liquid extraction procedure without derivatization using hexobarbital as the internal standard. Extraction recoveries observed from control samples containing four barbiturates range from 80% to 90%. Good one-point calibration data are obtained for all four barbiturates in the 50 to 3200 n~mL range. Interestingly, the one-point calibration data for pentobarbital are inferior to the other three barbiturates~ue to interference from the internal standard (ds-pentobarbital). The calibration data of pentobarbital are best described by a hyperbolic curve regression model. Precision data (% CV) for GC/MS analysis, over-all procedure, and day-to-day performance are approximately 2.0%, 6.0%, and 8.0%, respectively. With the use of a 2 mL sample size, the attainable detection limit is approximately 20 ng/mL.
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enzymatic digestion solid phase extraction and gas chromatography mass spectrometry of derivatized intact oxazepam in urine
Clinical Chemistry, 1991Co-Authors: Jeffrey G Langner, Cinnamon Edwards, B K Gan, R H Liu, L D Baugh, P Chand, J L Weng, Amrik S WaliaAbstract:Enzymatic digestion with beta-glucuronidase (EC 3.2.1.31) was used to release intact oxazepam from urine samples containing the d5-analog internal standard. The resulting specimens were extracted with Du Pont PREP Type W cartridge (processed by a PREP Automated Sample Processor), Bond Elut Certify, and J.T. Baker "spe" columns for comparison of the columns' extraction recovery and overall effectiveness. Methyl iodide/tetrahexylammonium hydrogen sulfate and N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (10 g/L) were used for the methylation and trimethylsilylation studies. We used a Hewlett-Packard HP 5790 mass-selective detector equipped with a 13-m J & W DB-5 column (5% phenyl polysiloxane phase) for gas chromatography/mass spectroscopy (GC/MS) analysis and the Thru-Put Target Software package for data processing. After several exploratory experiments, we adopted the Du Pont PREP system methylation procedure because of its effective recovery, the superior stability of the derivatization product, the possibility of incorporating a clean-up step, and the potential for high throughput. The extraction recovery from a set of control samples was 87%. Coefficients of variation obtained for six replicates of GC/MS analysis and for the overall procedure were 1% and 3%, respectively. Excellent linearity was established in the 50-8000 micrograms/L concentration range studied. With the use of 3-mL samples, a 20-microL final reconstitution volume, oxazepam at 50 micrograms/L was easily detected under the adopted operation conditions.
