A senior design course bridging power systems and powerelectronics: power quality impacts of electric vehicle charging

A new capstone design course, which combines elements of power electronics and power systems analysis, has been introduced at Georgia Tech as part of the newly revised curriculum. The paper explains the relationship of the new course with respect to the rest of the power curriculum, and how the course material and teaching style respond to various ABET requirements for an integrated design experience     

Toxicological Evaluation of Biotechnology Products – A Regulatory Viewpoint

Since the only recent recognition that toxicological evaluation biotechnology derived products by standard toxicological procedures may be inadequate, unpredictive or even impossible to perform, development of safety assessment has moved in two directions: 1. A Council Directive of the European Community has been enacted as of Juli 1987 (87/22/EEC). Thereby hormones, cytokines and other regulatory factors – blood products – monoclonal antibodies – vaccines derived by biotechnology methods submitted for obtaining marketing authorization will be dealt with at the CPMP level beyond national submission. 2. To allow separation of quality problems (e.g. identity, purity, determination of contaminants possibly encountered from the novel processes used in their manufacture, and from the complex structural and biological characteristics of the products) from those to be addressed by “pre-clinical” testing, Notes for Guidance (EEC) have been finalized (quality) or are under preparation (pre-clinical). For the latter an approach is sought which will hopefully allow the development of safe compounds employing those experimental approaches fit for each product (case by case approach). The current standing of this draft Note for Guidance will be presented.     

Calculation of thermal-gradient-induced stress birefringence in slab Lasers-I

A thorough analysis of the losses due to thermal-gradient-induced stresses in slab lasers is presented in which depolarization losses due to thermal-gradient-induced stresses are calculated properly by treating the changes in the dielectric impermeability tensor. In previous analyses of this problem, the approach in which the index of refraction is treated as a tensor quantity is only applicable in the limit of very small changes. Issues of how to correctly write the reduced-suffix forms of the tensors are also considered. Our formalism is then applied to an edge-pumped Yb:YAG slab laser. We consider straight-through propagation as an example of the formalism and indicate its application to the case of zigzag propagation.     

Effect of amniotic fluid volume on neonatal outcome in diamniotic twin pregnancies

PROBLEM: We assessed neonatal outcome of normal diamniotic twin pregnancies with known amniotic fluid (AF) volume. METHOD: The AF volume was empirically determined in 39 diamniotic twin gestations. The neonates were stratified by AF volume and evaluated for clinical outcome, gestational age, lecithin-sphingomyelin (L/S) ratio, and birth weight. RESULTS: Neonatal complications did not significantly differ among infants delivered from pregnancies with low (155 to 404 mL), moderate (405 to 807 mL), or high (808 to 5,430 mL) volumes of AF. Relatively constant volumes of AF were maintained throughout the 27 to 38 week range of gestational age, with no apparent correlation between AF volume and gestational age. Variations in the L/S ratio and newborn birth weights were also independent of AF volume. Gestational age was the only significant determinant of the frequency of neonatal complications. CONCLUSION: Amniotic fluid volume does not greatly affect neonatal outcome in normal diamniotic twin pregnancies.     

60-GHz pseudomorphic-MODFET low-noise MMIC amplifiers

The development of V-band low-noise monolithic microwave integrated circuits (MMICs) based on pseudomorphic modulation-doped FETs (P-MODFETs) is presented. These dual-stage MMICs incorporate P-MODFETs, with 0.35-μm×60-μm gates, as the active elements, electron-beam-written tuning elements, and DC-blocking and bias networks. The dual-stage chips exhibited a maximum gain of 10.2 dB at 59.5 GHz and a minimum noise figure of 5.3 dB, with an associated gain of 8.2 dB at 58.2 GHz. A cascaded four-stage amplifier using two MMIC modules exhibited 5.8-dB minimum noise figure with an associated gain of 18.3 dB at 58 GHz and up to 21.1 dB of maximum gain     

Use of spectral analysis in the detection of frequency differencesin the electrogastrograms of normal and diabetic subjects

The authors investigated the basal electrical rhythm (BER) of the stomach to determine if abnormalities of the BER occur in association with those gastric complaints in patients with long-term insulin-dependent diabetes. They recorded the basal electrical signal of the stomach in nine patients with diabetic gastroparesis and in 11 normal volunteers. They developed a microcomputer-based running spectral analysis technique (overlapping fast Fourier transforms) to analyze the recordings. They found no significant differences between the two subject groups in the prefed state but found a significantly higher proportion of episodes of high frequency, or tachygastria in the diabetic group in the postfed state (15.4-6.2%). The difference was also reflected in the higher postfed mean `peak' frequency of the diabetics. Both diabetics and normals show an increase in the mean of the peak frequency from pre- to postfed states, but the normals do not show an increase in episodes of tachygastria