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New multi-conductor spectral domain immittance functions are derived for modeling the mutual coupling between printed dipoles of arbitrary length embedded in stratified uniaxially anisotropic dielectrics. The coefficients for the newly derived multi-conductor spectral domain immittance functions are closed-form trigonometric functions, which shows that these new expressions are as simple as the single-conductor spectral domain immittance functions derived in previously published literature. Many different configurations of printed dipoles in stratified uniaxially anisotropic dielectrics are investigated for the first time. In particular, the effects of the thickness and the anisotropy ratio of each layer on the mutual coupling of the printed dipoles are determined. The numerical results from the new spectral domain immittance functions are compared to numerical results from commercial software and published literature with good agreement in all cases.

Novel 3-aza-7-phosphabicyclo[3.3.1]nonan-9-ones have been synthesised via the Mannich reaction of a phosphorinanone, a primary amine and formaldehyde. The new phosphorus–nitrogen (PN) compounds are rigid and adopt a twin-chair conformation both in solution and the solid states. The coordination properties of the PN compounds were explored and a stable platinum complex was synthesised in which the PN ligand was bonded through both donor atoms.

An electromagnetics-based design project was offered to a group of students as their final year (capstone) design project. Their objective was to create a suite of sensors to measure electromagnetic fields over a large range of frequencies. The project resulted in the design, fabrication and calibration of a field mill, fluxgate magnetometer, tuned search coils and a log-periodic dipole array antenna. The open-ended, experiential learning process exposed the students to numerous electromagnetic concepts, skills and learning methods not commonly found in traditional electromagnetic classroom settings. This paper provides an overview of the theory, design and output of the sensors.

Spectral domain immittance functions based on Hertz vector potentials are used to study the characteristics of a printed dipole with an arbitrary length embedded in stratified uniaxially anisotropic dielectrics. In particular, the resonant frequency and input impedance of the printed dipole are determined for various dielectric properties and thicknesses. Several newly computed results are compared to measurements, published literature, and commercial software for validation and are shown to have good agreement in all cases.

The derivation of a novel delta source based on a reduced Green's function (RGF) is presented for thin-wire scattering problems. The impressed electric field, typically represented by a delta source, is generated by a current defined at the source location. By using electrically small assumptions at the source location, the electric field integral equations (EFIEs) representing the impressed field created by the defined current can be evaluated analytically with an RGF. This impressed field is denoted here as the RGF delta source, or simply, the RGF source. The RGF source is in the range of the EFIE operator and does not contain the dipole that is present in the traditional delta source. The numerical results show the improved convergence of the new RGF source while maintaining accuracy comparable to that of existing delta source models used in other thin-wire models, such as the numerical electromagnetics code.

Numerically stable electric field integral equations (EFIE) are presented for electromagnetic scattering problems that may include both electrically small geometrically complex and electrically large regions. A reduced integrand is achieved by implementing quasi-static assumptions in the electrically small regions, full-wave methods in the electrically large regions, and applying appropriate coupling relations between the regions. Use of the method provides computational efficiency as well as insight into the conditions under which the electromagnetic fields within electrically small regions of the problem can be assumed to be primarily capacitive or inductive in nature. The theoretical development of the method is highlighted in this communication and then applied to examples of electrically small, inductively-loaded, and capacitively-loaded monopole antennas. The accuracy of the results is verified with two independent methods.

Spectral domain immittance functions can be used to numerically solve for the unknown surface currents on printed dipoles in layered anisotropic dielectrics. This solution requires the use of the spectral domain moment method and numerical integration. This paper presents a hybrid polar- and rectangular-numerical integration technique on the α-β plane useful for efficient evaluation of the spectral domain moment method and is defined in a manner that avoids unwanted poles. For validation, the convergence of the numerically computed input impedance of a printed dipole is presented.

The polymerase chain reaction is one of the most important reactions in molecular biology. Single stranded DNA is copied in a complex series of steps, at the core of which lies the action of the DNA polymerase. At each nucleotide along the template, the polymerase screens the dNTP pool until it finds the complementary dNTP. The insertion of each dNMP is a balance between high fidelity and rapid elongation. In this study the kinetics of the β type polymerase pyrococcus kodakaraensis (KOD) is analyzed. The kinetics is influenced by reaction conditions such as the dNTP pool composition and temperature. In a previous study by Viljoen et al. [2005, A macroscopic kinetic model for DNA polymerase elongation and high-fidelity nucleotide selection. Computational Biology and Chemistry 29, 101–110], a macroscopic kinetics expression of the polymerase chain reaction has been derived. The model contains four parameters that are intrinsic to a specific polymerase. The experiments to measure the temperature-dependence of the parameters for KOD DNA polymerase are reported. The results indicate that the optimal temperature for an equimolar dNTP pool is 72.5 ∘ C and the optimum temperature shifts to lower temperatures when the dNTP pool composition is biased.

Microwave engineering often involves extensive circuit analysis and design, typically requiring precise calculations. To expedite the handling of complicated design calculations, a Web-based design tool named Microwave Engineering Solutions (MES) was developed as a graduate student project in the Electrical and Computer Engineering Department at North Dakota State University (NDSU), Fargo, and is described in this paper. JavaScript, PHP, and Perl were used to develop MES, which consists of three design tools: 1) FilTech*a design tool for analog filters, 2) LMatch*a design tool for impedance matching, and 3) MicroLines*a design tool for striplines and microwave network analysis. MES is used by Electrical and Computer Engineering (ECE) students studying various aspects of electromagnetics and is freely available on the Web via the link at http://venus.ece.ndsu.nodak.edu//spl sim/ronelson/MESLink/index.html.

This study compares student learning outcomes from two instructional approaches: hybrid vs. traditional teaching method. The study applies a previously developed framework in order to assess the learned curriculum for the same upper division computer engineering course. It also analyzes how it is aligned with the intended curriculum. The same undergraduate computer engineering course was taught by two different instructors during two different semesters. Both instructors have extensive technical background and many years of practical engineering experiences in the related field. Both classes used an identical textbook, delivered similar set of course topics, had similar lab setup, required homework assignments as well as a semester-long team project. The key difference is the use of online lectures. Based on students’ responses to series of surveys and the result of final grades, this study compares their development in content knowledge and cognitive abilities to determine the effectiveness of the instructional approach. The study provides an interest in finding ways to truly utilize technology for improving student learning, particularly their development of cognitive abilities. The study also seeks the impact of the technology on lecturing styles and in-classroom dynamics. Furthermore, this study will help gain insights into instructional approaches concerning teaching and learning along the technological dimension.

Simplified electric field integral equations written in a manner suitable for numerical evaluation with the spectral domain moment method are presented here. In particular, these integral equations are written in terms of spectral domain immittance functions for multi-conductor problems and it will be shown that these expressions have an additional benefit, in terms of simplicity, over other methods because a numerical derivative is not required. The numerical computation of these expressions are validated by comparison with published results and commercial software.

A field-scale 4-celled, horizontal subsurface constructed wetland (CW) was installed to evaluate removal efficiencies of wastewater constituents in an industrial distillery effluent. Total and dissolved solids, NH4-N, TKN, P and COD were measured. This CW design provides four serial cells with synthetic liners and a river gravel base. The first two unplanted cells provide preliminary treatment. Specific gravel depths and ensuing biofilm growth provides anaerobic treatment in Cell 1 and anaerobic treatment in Cell 2. Cell 3 was planted with Typha latifolia with an inserted layer of brick rubble (for phosphorus removal). Locally grown reed, Phragmites karka was planted in Cell 4. COD was reduced from 8420 mg/l 3000 from Cell 1 to the outlet of Cell 4. Likewise other parameters: total and dissolved solids, ammonium and total nitrogen, and total P, indicated declining trends at the 4-celled CW effluent. This study reveals how high strength distillery wastewater strongly impacts morphology, aeration anatomy in the chiseled plant tissues, reed growth; and composition of the biofilm in the specialized substratum. The reliability of a CW for organic and nutrients reduction, in association with a poorly performing conventional system is discussed. There is an immense potential for appropriately designed constructed wetlands to improve high strength wastewaters in India.

Nitrogen pollution above a threshold level induces a eutrophication process in coastal creek ecosystems and consequently impacts on the water quality. The remedy for this scenario is the introduction of methods to enhance oligotrophication by means of constructed wetlands and buffer zones. This paper discusses new data on nitrogen flux and population changes in the primary consumers in the Bradley Creek ecosystem, adjacent to the Duck Haven Golf Course in southeastern North Carolina. In 1998-99, over different seasons, density distribution of the field populations of the fiddler crab Uca minax, was monitored as an indicator of environmental health. A control site at Whiskey Creek, adjacent to the University Center for Marine Sciences, was monitored in the same period since this site is not influenced by any golf course nutrient flux. The results pointed out that threshold level for optimum population density in Spartina grandiflora salt marsh is 0.1 mg/L of nitrates. A dense crab population, adjacent to the golf course with a buffer zone, was indicative of restoration of the estuarine ecosystem. A model, involving the use of constructed wetlands for oligotrophication, is being prepared on the basis of studies conducted by the University of South Alabama for a stormwater wetland constructed adjacent to the university's golf course.

Prisms of adult rat cortex were maintained in vitro in either aerobic conditions (control) or conditions simulating an acute ischaemic challenge (hypoxia with no added glucose). Endogenous glutamate efflux increased with time in ischaemic conditions, being 2.7 fold higher than control efflux at 45 min. Returning prisms to control solution after 20 min of simulated ischaemia resulted in glutamate efflux returning to near-control values. Endogenous GABA efflux in ischaemic conditions also increased, being 4.5 fold higher than control efflux at 45 min. Ischaemia-induced glutamate efflux was not accompanied by increased lactate dehydrogenase efflux and was unaltered by omitting calcium from the extra-cellular solution and adding EGTA (0.1 mM). Both GABA and the GABA-mimetic clomethiazole inhibited ischaemia-induced glutamate efflux, with IC(50) values of 26 and 24 microM respectively. The maximum inhibition by either drug was 60 - 70%. Bicuculline (10 microM) abolished the inhibitory effect of GABA (100 microM) but not clomethiazole (100 microM). Picrotoxin (100 microM) abolished the action of both GABA and clomethiazole. Pentobarbitone inhibited glutamate efflux at 100 - 300 microM (maximal inhibition: 39%). Bicuculline (10 microM) abolished this effect. These data suggest that ischaemia-induced glutamate efflux from rat cerebral cortex is calcium-independent and not due to cell damage up to 45 min. The inhibitory effect of GABA, clomethiazole and pentobarbitone on ischaemia-induced glutamate efflux appears to be mediated by GABA(A) receptors. The results suggest that clomethiazole, unlike pentobarbitone, is able to activate the GABAA receptor-linked chloride channel directly and not merely potentiate the effect of endogenous GABA.

An aqueous (NH4)2CO3 coprecipitation method, based on that of Groppi et al. [Appl. Catal. A 104 (1993) 101–108] was used to synthesize Sr1−xLaxMnAl11O19−α hexaaluminates. These materials were first synthesized by alkoxide hydrolysis. This synthesis route requires special handling of the starting materials and is not likely to be commercially practical. The materials prepared by (NH4)2CO3 coprecipitation have similar surface areas as those prepared by the alkoxide hydrolysis method. Their CH4 oxidation activity, measured as the temperature needed for 10% conversion of methane, is higher than those prepared by alkoxide hydrolysis. The La-substantiated material, LaMnAl11O19−α, shows high surface area with 19.3 m2/g after calcination at 1400°C for 2 h. It is active for CH4 oxidation with T10% at 450°C using 1% CH4 in air and 70 000 cm3/h g space velocity. The stability and activity of LaMnAl11O19−α prepared by (NH4)2CO3 coprecipitation method is a simple and important step forward for the application of CH4 catalytic combustion for gas turbines.

One of the places where it is critical to prevent equipment malfunction due to electromagnetic interference is in the hospital operating room. Unfortunately, the electromagnetic environment in hospital operating rooms can be quite harsh. The electromagnetic fields present in this environment are created by distant sources such as AM and FM broadcast transmitting antennas as well as local sources such as electrosurgical units. Measured values are reported of electric and magnetic field strengths created by typical electrosurgical units. Measurements were taken in operating rooms at the Department of Veterans Affairs Medical Center in Fargo, ND, and were made for three electrosurgical units (ESU) operating modes. All three components of the electric and magnetic fields were determined as a function of frequency. Field strengths as large as 153 dB/spl mu/V/m and 76 dB/spl mu/A/m were measured 1 m from the electrosurgical unit.

Over the past several years, Federal and international regulations limiting the interference potential of electronic devices have forced designers and manufacturers of these devices to consider the electromagnetic compatibility (EMC) of their products. Although there are a few universities which offer courses to prepare electrical engineers for this challenge, many faculties are hesitant to introduce courses dealing with EMC. A case study is presented of how a such a course was developed at North Dakota State University, USA. Issues and concerns that occurred throughout the development and implementation process are discussed and encouragement is given to faculty who are interested in including EMC in their curricula.

International audience

Electrostatic discharge, or ESD, is a common hazard in the electronics industry. Despite the fact that RFID has been in use for nearly forty years, there has been little to no discussion in the scholarly literature on how ESD interacts with RFID tags as a system. The intent of this chapter is to give the reader an overview of ESD and the aspects of RFID with which it interacts. Next, a view of ESD protections incorporated into RFID ICs is presented. A statistical examination of RFID tag susceptibility is summarized, and the chapter ends with a discussion of ESD issues that affect the RFID manufacturing environment. This document should, therefore, provide the reader with a comprehensive view of the interaction of RFID with ESD as well as a starting point for studying related areas.

Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biological pathways in the aetiology of autism. However, despite the strong influence of genetic factors, association studies have yet to identify statistically robust, replicated major effect genes or SNPs. We apply the principle of the SNP ratio test methodology described by O'Dushlaine et al to over 2100 families from the Autism Genome Project (AGP). Using a two-stage design we examine association enrichment in 5955 unique gene-ontology classifications across four groupings based on two phenotypic and two ancestral classifications. Based on estimates from simulation we identify excess of association enrichment across all analyses. We observe enrichment in association for sets of genes involved in diverse biological processes, including pyruvate metabolism, transcription factor activation, cell-signalling and cell-cycle regulation. Both genes and processes that show enrichment have previously been examined in autistic disorders and offer biologically plausibility to these findings. © 2011 Macmillan Publishers Limited All rights reserved.

Every year researchers and engineers are finding new and useful applications for Radio Frequency Identification (RFID) systems (Finkenzeller, 2003). Because of the growing use of RFID systems, many different areas of research have also been developed to improve the performance of such systems. A few of these areas of research include novel antenna designs (Rao et at., 2005; Calabrese & Marrocco, 2008; Amin et al. 2009), analysis on the backscatter properties of RFID tags (Yen et al., 2007; Feng et al., 2006), mutual coupling between RFID tags (Li et al., 2008; Owen et al., 2009) and the deployment of RFID systems to complex and extreme environments (Qing & Chen, 2007; Sanford, 2008). There are many aspects to each area of research in RFID. A major topic in many of these areas involves research on the antenna design for RFID tags. This chapter will focus on the design of efficient space-filling antennas for passive UHF RFID tags. First, an introduction to RFID systems is presented. This is done by describing the major components in a RFID system and how they communicate. Then, the particular backscattering properties of a passive tag are described from a unique electric field integral equation standpoint and from an overall systems perspective (i.e., using the Friis transmission equation). This discussion will then be followed by a section describing a practical design process of various space-filling antennas for passive tags. Finally, a summary of future work and a conclusion about the chapter is presented.

Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

Protein S and C4b-binding protein (C4BP) form a tight complex (Kd approximately 0.6 nM) the physiologic purpose of which is unknown. The participation of protein S in this complex was investigated using site-specific mutagenesis. Normal recombinant human protein S (rHPS) and five specifically mutated protein S analogs were expressed in transformed human kidney 293 cells and the following properties were characterized: solution-phase C4BP binding, ability to be cleaved by thrombin, ability to act as a cofactor in the activated protein C-catalyzed inactivation of factor Va, and gamma-carboxyglutamic acid content. In some cases, beta-hydroxyaspartic acid plus beta-hydroxyasparagine content was also determined. Binding studies indicated that while clearly important for a high affinity interaction, the amino acid sequence Gly605-Ile614 identified by Walker (Walker, F J. (1989) J. Biol. Chem. 264, 17645-17648) does not account for all the binding energy of the HPS-C4BP interaction. All mutants perturbed in this region or lacking it altogether displayed reduced C4BP binding, and some retained anticoagulant cofactor function. Neither human factor X nor human steroid-binding protein had any measurable ability to compete with plasma HPS for C4BP binding. Furthermore, bovine protein S and a rHPS analog with bovine sequence from Gly597-Trp629 bound to human C4BP with the same affinity as did HPS, and both proteins substituted effectively for HPS as a cofactor for activated protein C in an otherwise human anticoagulation system. Together these results suggest that optimal binding of protein S to C4BP requires the putative alpha-helix Gly605-Ile614, as well as other undetermined regions of protein S, and that the regions of HPS responsible for C4BP binding and activated protein C cofactor function are structurally isolated.

Summary Germination of non-dormant peanut seeds is characterized by a “climacteric-like” pattern in ethylene production. Treatment with ethylene resulted in the autocatalytic stimulation of ethylene synthesis, accompanied by an acceleration in the rate of germination. It appears that the availability of ACC could be limiting during the initial phases of the germination process. An increase in the conversion of ACC to ethylene during germination suggest an increase in EFE activity of the seeds. Continuous application of 100 µM octanoic acid during the germination period resulted in the inhibition of seed germination. However, a brief treatment with 1 to 100 µM octanoic acid resulted in the stimulation of germination due to an increase in the sensitivity of the seed tissue to ethylene.

The performance of many different dual frequency tag configurations were tested in a commercially available dual frequency RFID system. It has been shown that the interaction between the LF and UHF tags can have a significant impact (i.e., 91.84% reduction in read range) on the performance of each individual tag. But, in all cases it has been shown that by proper placement of the LF and UHF RFID tags the performance of each individual tag in the dual-frequency tag can be preserved. In the Rampart line case to preserve the performance of an individual tag a larger footprint was not needed.

The mutual coupling between two broadside printed dipoles in stratified anisotropic dielectrics is evaluated using newly derived spectral domain immittance functions. It is shown that an increase in the permittivity in the layer below the dipoles in the direction of the optical axis can significantly increase the mutual coupling while an increase in the permittivity in the direction orthogonal to the optical axis in the layer above the dipoles could be used to reduce the mutual coupling. The isotropic cases are compared to published literature and commercial software for validation and good agreement is shown.

Among the vitamin K-dependent plasma proteins, only protein S contains the post-translationally modified amino acid erythro-beta-hydroxyasparagine (Hyn). Protein S also contains erythro-beta-hydroxyaspartic acid (Hya). The function of these unusual amino acids, located in the epidermal growth factor-like domains, is unknown. To determine if these post-translational modifications contribute to the functional integrity of human protein S (HPS), recombinant human protein S lacking Hya and Hyn (rHPSdesHya/Hyn) was purified from the medium of human kidney 293 cells that were transfected with HPS cDNA and grown in the presence of the hydroxylase inhibitor 2,2'-dipyridyl. Solution-phase equilibrium binding studies revealed that rHPSdesHya/Hyn binds C4b-binding protein (C4BP) in a manner indistinguishable from recombinant HPS and plasma-derived HPS, exhibiting a Kd in the presence of 2 mM CaCl2 of approximately 0.7 nM and a Kd in the presence of 4 mM EDTA approximately 10-fold higher. In a purified component system, rHPSdesHya/Hyn displayed normal anticoagulant cofactor activity in the activated protein C-catalyzed inactivation of coagulation factor Va bound in the prothrombinase complex. In addition, digestion of rHPSdesHya/Hyn with thrombin in the presence of EDTA appeared normal, and 2 mM CaCl2 prevented the cleavage. Together these results suggest that the post-translational modifications of Asn and Asp residues are not necessary for the macromolecular or Ca2+ interactions associated with the anticoagulant and C4BP binding characteristics of HPS.

Previous work has shown that the transverse and longitudinal position of an emissions source within a gigahertz transverse electromagnetic (GTEM) cell will affect the measured voltages at the apex of the cell. Since the emissions source(s) on an EUT may not always correspond with the measurement position origin, this may have an effect on the correlation algorithm used to simulate radiated emissions at an open-air test site (OATS). This paper analyzes why such measurement differences occur and shows the effect shifts in the emissions source location relative to the measurement position origin has on two correlation algorithms. Specifically, it examines the 3-position total radiated power algorithm and the 9-position multipole algorithm.

A new method for calculating the equivalent circuit of a quasi-static region based on scattered fields is presented. Two problems with a quasi-static region are chosen to validate the procedure. It is then shown that the geometry in the quasi-static region can be modeled accurately in Mininec as an equivalent circuit and that the computation times with the equivalent circuit are significantly less.

A printed Rampart line antenna with a dielectric superstrate for passive radio frequency identification (RFID) tags is presented. A design process is outlined to determine the number of elements used in the rampart line antenna to achieve the required gain for the desired read range. An inductive loop is then added to the port to match the antenna with the passive tag circuitry. It is shown that a passive tag with a printed Rampart line antenna and a dielectric superstrate can achieve comparable read ranges to commercially available passive RFID tags.

A full-wave analysis for determining the resonant frequency of a rectangular microstrip patch on multiple uniaxial anisotropic layers with or without an anisotropic overlay is presented. Two independent methods are used to derive the immittance matrix for the patch, from which the resonant frequency is determined. They are the Hertz vector potentials and the modified spectral domain immittance approach. Numerical results of the resonant frequency are given for several patch configurations, including cases of a patch on a single anisotropic layer, a patch on a double layer with one layer anisotropic and one layer isotropic, a suspended patch resonator with anisotropic substrate, a patch with anisotropic overlay and a patch on two anisotropic substrates with an anisotropic overlay. Changes in the resonant frequency of up to 58% are reported as n/sub x//n/sub y/ is changed from 1.0 (for isotropic substrates) to 2.0. >

The purpose of this study was to determine the ESD susceptibility of commercially available label-enclosed RFID tags. Six different types of adhesive labels with RFID transponders were subjected to ESD in different testing environments. Initial data shows that most of the tags were sufficiently protected from fairly large discharges by their covering material. The magnitude of discharge and distance of the discharge to the IC did not have the expected effects on the tags. Instead, the presence of a ground plane and low label resistance were correlated to larger damage rates. The type of antenna and IC also played a role in susceptibility.

Closed form expressions are provided for currents induced in small loop antennas and the magnetic fields created (e.g., scattered) by those induced currents. The accuracy of the expressions has been verified with MININEC, a commonly-used electromagnetics software code. Applications of this work are noted, one of which is a new way of thinking about the operation of inductivelycoupled RFID (radio frequency identification) systems. As an alternative to viewing such systems in terms of the coupling coefficient (as commonly done with transformertype systems) we view it from an induced-current/scatteredfield perspective. The closed-form expressions developed here can be used as tools for EMC and RFID personnel to estimate the fields scattered from RFID loop. The results can also be used to improve general understanding of inductively-coupled noise, and provide estimates of the voltage and current induced in small “sniffer” probes. Keywords-component; RFID systems, loops; induced currents; scattered fields; incident plane wave, sniffer probes.

RFID systems will soon become ubiquitous. This paper provides insight into one way of viewing the operation of high-frequency RFID systems that use passive tags. The relationship between the impedance of the tag circuit and the fields scattered by the tag are highlighted using two indepen- dent numerical codes. In addition, analytical expressions and numerical results for the scattered electric field are provided for a dipole with an assumed sinusoidal current distribution. Such results provide EMC engineers with an approximate method of determining the fields scattered from passive, high-frequency RFID tags.

All earth-looking photographs acquired by Space Shuttle astronauts are identified, located, and catalogued after each mission. The photographs have been entered into a computerized database at the NASA Johnson Space Center. The database in its two modes - computer and catalog - is organized and presented to provide a scope and level of detail designed to be useful in Earth science activities, resource management, environmental studies, and public affairs. The computerized database can be accessed free through standard communication networks 24 hours a day, and the catalogs are distributed throughout the world. Photograph viewing centers are available in the United States, and photographic copies can be obtained through government-supported centers.

Although surface mount components are widely used in high frequency circuit design, the distortion of the characteristics of these devices at high frequencies should be considered during analog circuit design. The work reported in this paper employs a novel combination of measurement results and fast computational tools to provide the circuit response in both time and frequency domains. In particular, this method allows very fast computation of the circuit response (in the time or frequency domain) for systems composed of a variety of elements - including those for which the equivalent circuit is not known. This technique allows the designer to carefully (and quickly) investigate the contribution of individual components to the overall response. In this paper a brief overview is provided of the methods employed.

In this contribution, the impedance of a power/GND plane pair with the inclusion of the effect of anti-pads (voids) is computed by applying a hybrid finite difference time domain (FDTD)-field theory procedure. The power/GND plane is analyzed by dividing the entire structure into a grid of square segments. Then each segment is replaced by an equivalent circuit module. The topology and elements of these modules are extracted by an analytical procedure, using the solution of Helmholtz equation while applying the FDTD method for regular regions. Then, an equivalent circuit topology is constructed by superimposition of all pre-made segments. This method is extended to include the anti-pads. The analytical/simulation results are presented, and those results are compared to the data obtained from preliminary measurements.

The effect of the power plane inductance on the self-resonant frequency of decoupling capacitors in high-density printed circuit boards (PCBs) is discussed. Several examples are provided which illustrate that the placement location of decoupling capacitors has a considerable effect on the characteristic impedance of capacitors, and hence their capability to provide charge during IC switching. Simulation models and results are provided along with experimental results to illustrate the parasitic effects of interconnect on capacitors' characteristic impedance.

Passive components such as capacitors and inductors are often used in high-frequency circuits. EM engineers often model the frequency response of these components by adding "parasitic" components to the circuit model. For instance, parasitic resistors and inductors are added to the model of a capacitor. Some capacitors also exhibit an electrical response when stressed physically. This response can be significant. This response is called the "microphonic effect" because the frequency of the response is often in the audible range. A simple operational amplifier circuit is used to examine this response for several off-the-shelf capacitors. Considerable variation is observed-depending on capacitor type, capacitor size, and physical location.

Simulated ischemic conditions (hypoxia-hypoglycaemia) in vitro enhanced glutamate efflux from rat cerebrocortical prisms. Here we characterised efflux mechanisms using pharmacological tools. The Na(+) channel blocker TTX (1 microM) did not affect ischemia-induced efflux, while sipatrigine (100 microM), a Na(+)/Ca(2+) channel blocker and omega-conotoxin MVIIC (2 microM), an N/P/Q type Ca(2+) channel blocker, inhibited efflux by fractions of 0.53 and 0.46, respectively (1.00 corresponding to total inhibition). Omission of extracellular Ca(2+) and addition of EGTA (2 mM) inhibited ischemia-induced efflux only during the first 25 min of incubation. A similar result was observed on omission of extracellular Ca(2+) together with addition of La(3+) (10 microM) and Mg(2+) (6 mM). TTX, sipatrigine and La(3+)/Mg(2+) all inhibited control efflux. Ischemia-induced efflux was sensitive to the volume activated anion channel inhibitor NPPB (100 microM) only after the first 25 min of incubation, with the maximal fraction inhibited being 0.54. The glutamate transporter inhibitor D,L-TBOA reduced ischemia-induced efflux throughout a 45-min incubation period, and enhanced efflux from control tissue. D,L-TBOA inhibited efflux at 30 min by a maximum fraction of 0.49, at 50 microM. These data indicate that the early phase of ischemia-induced glutamate efflux is in part Ca(2+) dependent, while the later phase involves volume activated anion currents and both phases involve excitatory amino acid transporters.

When lightning strikes an airplane, it generally attaches to a leading edge such as the nose, wing tips, forward part of a vertical tail, or some other leading edge protrusion and leaves via a sharp trailing edge such as the rear wing tip or tail. In order to clearly visualize this phenomena, a lightning attachment simulator was designed and constructed by students at North Dakota State University for the Naval Air Warfare Center Aircraft Division. This paper describes the design and development of the simulator.

One method of protecting electronic components from the effects of ESD is to shunt the ESD current to ground. The response of the protection devices can be affected, however, by parasitic components in the component structure, as well as board parasitics such as the inductance of the traces and connectors to which the protective device is connected to. The effect of component lead length is investigated in this work for four components: a 100-/spl Omega/ film resistor, a 33-V MOV, and two unidirectional TVS diodes. Up to 15.6 dB additional attenuation is provided by shortening the leads of the protection device.

International audience

A course entitled 'Designing for Electromagnetic Compatibility' was recently offered at North Dakota State University. The course had both a lecture and measurements component. A unique supplement to the measurements component was made possible by area industries. This study describes the course development and content. >

The following question is examined: can image theory be used to provide reasonably accurate results for electrostatic problems involving finite conducting structures? The moment method is used in this investigation to determine the surface charge distribution induced on a finite conducting plane by a point charge above the plane. The size of the plane and position of the charge are arbitrary. Results are compared with those obtained from image theory for various point charge positions. These results can provide guidelines regarding when it is appropriate to use image theory to obtain reasonably accurate results for electrostatic problems involving finite conducting structures.

For several years faculty members in the Department of Electrical and Computer Engineering and the Department of Physics at North Dakota State University have been creating new courses or substantially revising existing courses in order to better serve current industrial needs and foster regional economic development. In particular, three new courses have been developed with this objective: ECE 455/655 Designing for Electromagnetic Compatibility, ECE 453/ 653 Signal Integrity, and Physics 499/696, Optics for Scientists and Engineers. These and other courses position the institution to be a vital part in the development of engineering companies in the region.

This study compares the emissions from several different printed circuit board assemblies. Each printed circuit board assembly had different techniques applied to reduce the radiated emissions. The printed circuit boards were tested in an anechoic chamber to measure the emissions. The results of these tests were evaluated to determine if there were any differences in measured emissions. Two criteria were compared: number of signals and average magnitude of the signals.