181 research outputs found

    Design Optimization of Transistors Used for Neural Recording

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    Neurons cultured directly over open-gate field-effect transistors result in a hybrid device, the neuron-FET. Neuron-FET amplifier circuits reported in the literature employ the neuron-FET transducer as a current-mode device in conjunction with a transimpedance amplifier. In this configuration, the transducer does not provide any signal gain, and characterization of the transducer out of the amplification circuit is required. Furthermore, the circuit requires a complex biasing scheme that must be retuned to compensate for drift. Here we present an alternative strategy based on the design approach to optimize a single-stage common-source amplifier design. The design approach facilitates in circuit characterization of the neuron-FET and provides insight into approaches to improving the transistor process design for application as a neuron-FET transducer. Simulation data for a test case demonstrates optimization of the transistor design and significant increase in gain over a current mode implementation

    Microelectronics Process Engineering at San Jose State University: A Manufacturing-Oriented Interdisciplinary Degree Program

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    San Jose State University\u27s new interdisciplinary curriculum in Microelectronics Process Engineering is described. This baccalaureate program emphasizes hands-on thin-film fabrication experience, manufacturing methods such as statistical process control, and fundamentals of materials science and semiconductor device physics. Each course of the core laboratory sequence integrates fabrication knowledge with process engineering and manufacturing methods. The curriculum development process relies on clearly defined and detailed program and course learning objectives. We also briefly discuss our strategy of making process engineering experiences accessible for all engineering students through both Lab Module and Statistics Module series

    Echocardiographic Guidance During Neonatal and Pediatric Jugular Cannulation for ECMO

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    Background Internal jugular vein extracorporeal membrane oxygenation (ECMO) cannula position is traditionally confirmed via plain film. Misplaced cannulae can result in need for repositioning and increased morbidity. Echocardiography (ECHO) may be used during cannulation as a more accurate means of guiding cannula position. This study reviews the effect of a protocol encouraging the use of ECHO at cannulation. Methods and materials Single institution retrospective review of patients who received ECMO support using jugular venous cannulation. We compared those who underwent ECHO (ECHO+) at the time of cannulation with those who did not (ECHO−). Results Eighty-nine patients were included: 26 ECHO+, 63 ECHO−. Most ECHO+ patients underwent dual-lumen veno-venous (VV) cannulation (65%); 32% of ECHO− patients had VV support (P = 0.003). There was no difference in the rate of cannula repositioning between the two groups: 8% ECHO+ and 10% ECHO−, P = 0.78. In the VV ECMO subgroup, ECHO+ patients required no repositioning (0/17), while 20% (4/20) of ECHO− VV patients did (P = 0.10). After cannulation, there were 0.58 ECHO studies per patient to verify cannula position in the ECHO+ group compared with 0.22 in the ECHO− group (P = 0.02). Each group had a major mechanical complication: atrial perforation from a guidewire during cannulation in ECHO+ and late atrial perforation from a loose cannula in ECHO−, and there was no difference in minor complications. Conclusions ECHO guidance during neonatal and pediatric jugular cannulation for ECMO did not decrease morbidity or reduce the need for cannula repositioning. ECHO may still be a useful adjunct for precise placement of a dual-lumen VV cannula and during difficult cannulations

    A Case Study of a Co-Instructed Multidisciplinary Senior Capstone Project in Sustainability

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    As societal challenges involving sustainable development increase, the need to effectively integrate this inherently multidisciplinary topic into existing curricula becomes more pressing. Multidisciplinary, team-taught, project-based instruction has shown effectiveness in teaching teamwork, communication, and life-long learning skills, and appreciation for other disciplines. Unfortunately, this instruction mode has not been widely adopted, largely due to its resource-intensiveness. Our proposed co-instruction model of multidisciplinary senior project administration was tested to see if it could effectively teach sustainability topics and duplicate the known benefits of team-taught instruction, while overcoming its resource-intensiveness. A case study of a co-instructed senior project was undertaken with students and faculty from electrical and mechanical engineering, business, political science, and industrial design. The participating students were compared to the control group, i.e. students who chose to complete a traditional disciplinary senior project instead. Extensive assessment was performed with pre/post quizzes, online surveys, focus groups, and course deliverables. The multidisciplinary projects outperformed traditional senior projects in 4 out of the 5 participating courses. However, the students in the multidisciplinary project rated their satisfaction with the experience lower on average than the control group. A strong, positive correlation between students’ project satisfaction and rating of other instruction aspects (0.50 \u3c r \u3c 0.7, p \u3c 0.01) was discovered, which has implications for all project-based instruction. Participating faculty generally found the process illuminating and engaged in scholarship and creative endeavors as a result

    Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe

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    The Extragalactic Background Light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ~10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts (GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of gamma-ray flux attenuation by the EBL. We place upper limits on the gamma-ray opacity of the Universe at various energies and redshifts, and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the "baseline" model of Stecker et al. (2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A. Reimer, L.C. Reye
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