Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL) is the process whereby species generated at electrodes undergo high-energy electron-transfer reactions to form excited states that emit light. The first detailed ECL studies were described by Hercules and Bard et al. in the mid-1960s, although reports concerning light emission during electrolysis date back to the 1920s by Harvey. After about 40 years study, ECL has now become a very powerful analytical technique and been widely used in the areas of, for example, immunoassay, food and water testing, and biowarfare agent detection. ECL has also been successfully exploited as a detector of flow injection analysis (FIA), high-performance liquid chromatography (HPLC), capillary electrophoresis, and micro total analysis (μTAS). Figure 1 illustrates a time line of various events in the development of ECL. A literature survey using SciFinder Scholar reveals that more than 2000 journal articles, book chapters, and patents on various topics of ECL have been published. The overall number of publications, as shown in Figure 2, has increased exponentially over the past 20 years, of which 40–50% were biorelated. Similar amounts of ECL papers could be also found from the Thomson ISI Web of Science as well as † Telephone (601) 266 4716; fax (601) 266 6075; e-mail wujian.miao@ usm.edu. Wujian Miao received his undergraduate diploma in chemistry from Nantong University (Nantong, China) in 1982, his M.Sc. degree in analytical chemistry from Zhongshan University (Guangzhou, China, with Jinyuan Mo) in 1991, and his Ph.D. degree in electrochemistry from Monash University (Melbourne, Australia, with Alan M. Bond) in 2000. He then served as a Research Scientist in CSIRO (Melbourne, Australia), followed by a postdoctoral fellowship at the University of Texas at Austin with Allen J. Bard in 2001. Since 2004 he has served as an assistant professor of chemistry at the University of Southern Mississippi.

Electrogenerated Chemiluminescence and Its Biorelated Applications

Single-bubble sonoluminescence occurs when an acoustically trapped and periodically driven gas bubble collapses so strongly that the energy focusing at collapse leads to light emission. Detailed experiments have demonstrated the unique properties of this system: the spectrum of the emitted light tends to peak in the ultraviolet and depends strongly on the type of gas dissolved in the liquid; small amounts of trace noble gases or other impurities can dramatically change the amount of light emission, which is also affected by small changes in other operating parameters (mainly forcing pressure, dissolved gas concentration, and liquid temperature). This article reviews experimental and theoretical efforts to understand this phenomenon. The currently available information favors a description of sonoluminescence caused by adiabatic heating of the bubble at collapse, leading to partial ionization of the gas inside the bubble and to thermal emission such as bremsstrahlung. After a brief historical review, the authors survey the major areas of research: Section II describes the classical theory of bubble dynamics, as developed by Rayleigh, Plesset, Prosperetti, and others, while Sec. III describes research on the gas dynamics inside the bubble. Shock waves inside the bubble do not seem to play a prominent role in the process. Section IV discusses the hydrodynamic and chemical stability of the bubble. Stable single-bubble sonoluminescence requires that the bubble be shape stable and diffusively stable, and, together with an energy focusing condition, this fixes the parameter space where light emission occurs. Section V describes experiments and models addressing the origin of the light emission. The final section presents an overview of what is known, and outlines some directions for future research.

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Single bubble sonoluminescence

Tunneling spectroscopy has played a central role in the experimental verification of the microscopic theory of superconductivity in classical superconductors. Initial attempts to apply the same approach to high-temperature superconductors were hampered by various problems related to the complexity of these materials. The use of scanning tunneling microscopy and spectroscopy (STM and STS) on these compounds allowed the main difficulties to be overcome. This success motivated a rapidly growing scientific community to apply this technique to high-temperature superconductors. This paper reviews the experimental highlights obtained over the last decade. The crucial efforts to gain control over the technique and to obtain reproducible results are first recalled. Then a discussion on how the STM and STS techniques have contributed to the study of some of the most unusual and remarkable properties of high-temperature superconductors is presented: the unusually large gap values and the absence of scaling with the critical temperature, the pseudogap and its relation to superconductivity, the unprecedented small size of the vortex cores and its influence on vortex matter, the unexpected electronic properties of the vortex cores, and the combination of atomic resolution and spectroscopy leading to the observation of periodic local density of states modulations in the superconducting and pseudogap states and in the vortex cores.

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Scanning tunneling spectroscopy of high-temperature superconductors

An assembly that contains a medical device and biological material within which the medical device is disposed. The assembly has a direct or alternating current magnetic susceptibility within the range of from about plus 1 x 10-2 centimeter-gram-seconds to about minus 1 x 10-2 centimeter-gram-seconds.

Medical device with low magnetic susceptibility

A shielded medical device implanted in a biological organism. The device has a magnetic shield, and the magnetic shield contains a layer of nanomagnetic material; such layer has a morphological density of at least 98 percent; and it is bonded to the medical device by means of an interlayer with a thickness of less than about 10 microns. The nanomagnetic material in such layer has a saturation magnetization of from about 1 to about 36,000 Gauss, a coercive force of from about 0.01 to about 5,000 Oersteds, a relative magnetic permeability of from about 1 to about 500,000, and an average particle size of less than about 100 nanometers.

Magnetically shielded assembly

Defining the unknowns of sonoluminescence

An article comprising a multi-port variable capacitor is disclosed. In one embodiment, a movable plate is suspended above at least a first and a second, fixed, electrically-isolated electrode. The first electrode is electrically connected to a bias supply, and the second electrode is electrically connected to an AC signal-carrying line. As bias is applied across the first electrode and the movable plate, an electrostatic attraction is developed therebetween that causes the movable plate to move downwardly towards the first electrode. The capacitance of the variable capacitor increases as the separation distance between the movable plate and the fixed electrodes decreases. Unlike conventional variable capacitors, in the present multi-port variable capacitors, the bias (delivered via the first electrode) and the signal (delivered via the second electrode) are electrically isolated from one another. As such, the bias (DC) and signal (AC) paths are advantageously electrically isolated. In an additional embodiment, the movable plate of the present variable capacitor is operable to tilt. The ability to tilt provides additional “signal processing” (i.e., logic) capabilities to the present multi-port variable capacitors. In additional embodiments, an article in accordance with the present teachings comprises a monolithically-integrable, tunable LC circuit, and a variable-frequency oscillator. In such LC circuits and oscillators, the multi-port variable capacitor described herein is used to tune the resonant frequency of the circuit.

Article comprising a multi-port variable capacitor

Inductors play a key role in wireless front-end circuitry, yet are not generally well suited for conventional RF integrated-circuit (RFIC) fabrication processes. We have developed inductors that can be fabricated on a conventional RFIC silicon substrate, which use warping members to assemble themselves away from the substrate to improve quality factor (Q) and self-resonance frequency (SRF), and to provide a degree of variation in inductance value. These self-assembling variable inductors are realized through foundry provided microelectromechanical systems (MEMS) processing and have demonstrated temperature stable Q values greater than 13, SRF values well above 15 GHz, and inductance variations greater than 18%. Simulations suggest the potential for Q values above 20 and inductance variations greater than 30%, with optimized processing.

Self-assembling MEMS variable and fixed RF inductors

A micro-opto-electromechanical systems (MOEMS) device comprises a micro-electromechanical systems (MEMS) device and a silicon optical-bench (SiOB) device or system. The MEMS device interacts with the SiOB mechanically or electromagnetically. In one embodiment, the MEMS device is operable to provide a switching function for the SiOB device. The MEMS device comprises an actuator that is mechanically linked to an optical interruptor that prevents at least a portion of an optical signal incident thereon from propagating therethrough. In an actuated state, the actuator causes the optical interrupter to move into an optical path of an optical signal traveling through an SiOB device. The signal is at least partially reflected or absorbed such that only a portion of the signal propagates beyond the point of contact with the optical interrupter. Since SiOB processing is typically incompatible with MEMS device processing, the MEMS and SiOB devices are formed on separate supports and then attached, such as via flip-chip bonding methods.

Micro-opto-electromechanical devices and method therefor

Small-angle neutron scattering and magnetic decoration both demonstrate a topological transition in the flux line lattice (FLL) in ErNi{sub 2}B{sub 2}C. The high-field square lattice slowly transforms into a hexagonal lattice via an area preserving [100] rhombohedral distortion below roughly 500Oe. The square FLL is aligned with the [110] direction of the tetragonal crystal, while the two domains of the hexagonal FLL are aligned with [100] and [010]. The differences in pinning for the two FLL topologies are reflected in the rf kinetic inductance. {copyright} {ital 1997} {ital The American Physical Society}

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Bradley Paul Barber

Papers

Defining the unknowns of sonoluminescence

Article comprising a multi-port variable capacitor

Self-assembling MEMS variable and fixed RF inductors

Micro-opto-electromechanical devices and method therefor

Observation of a Field-Driven Structural Phase Transition in the Flux Line Lattice in ErNi 2 B 2 C