There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

This International Myeloma Working Group consensus updates the disease defi nition of multiple myeloma to include validated biomarkers in addition to existing requirements of attributable CRAB features (hypercalcaemia, renal failure, anaemia, and bone lesions). These changes are based on the identifi cation of biomarkers associated with near inevitable development of CRAB features in patients who would otherwise be regarded as having smouldering multiple myeloma. A delay in application of the label of multiple myeloma and postponement of therapy could be detrimental to these patients. In addition to this change, we clarify and update the underlying laboratory and radiographic variables that fulfi l the criteria for the presence of myeloma-defi ning CRAB features, and the histological and monoclonal protein requirements for the disease diagnosis. Finally, we provide specifi c metrics that new biomarkers should meet for inclusion in the disease defi nition. The International Myeloma Working Group recommends the implementation of these criteria in routine practice and in future clinical trials, and recommends that future studies analyse any diff erences in outcome that might occur as a result of the new disease defi nition.

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International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma.

Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.

/pdf/a-review-of-single-phase-improved-power-quality-ac-dc-2pm6h4zjxq.pdf

A review of single-phase improved power quality AC-DC converters

Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

/pdf/light-emitting-diodes-ubzde6g9qc.pdf

Light-emitting diodes

Solid-state switch mode AC-DC converters having high-frequency transformer isolation are developed in buck, boost, and buck-boost configurations with improved power quality in terms of reduced total harmonic distortion (THD) of input current, power-factor correction (PFC) at AC mains and precisely regulated and isolated DC output voltage feeding to loads from few Watts to several kW. This paper presents a comprehensive study on state of art of power factor corrected single-phase AC-DC converters configurations, control strategies, selection of components and design considerations, performance evaluation, power quality considerations, selection criteria and potential applications, latest trends, and future developments. Simulation results as well as comparative performance are presented and discussed for most of the proposed topologies.

Comprehensive Study of Single-Phase AC-DC Power Factor Corrected Converters With High-Frequency Isolation

Visible Light Communication (VLC) shows up as a trend for short range wireless networks, which comes as a promising breakthrough for industry. However, this technology still faces challenges on the technical side. In particular, the selection of the appropriate circuit driver to fulfill simultaneously both lighting and communication functions is a non-trivial task. This paper reviews driver solutions intended for VLC applications, summarizing published research according to a proposed classification. Additionally, switched mode circuits stand out among the current works, supporting low data rates with higher overall efficiency at greater power levels. On the other hand, linear power amplifiers are the preferred choice for high data rate systems.

Review of LED drivers for Visible Light Communication

One important aspect for the design of dimming ballasts for fluorescent lamps is the output power range that can be obtained. Some applications require that the output power can be reduced below 10%. However, in some ballast designs, there is no easy way to reduce the output power to the required minimum level without finding instabilities that could lead to light flicker, audible noise or arc extinction. In this paper, a new power-dependent small-signal model for fluorescent lamps is presented. This model is based in a double-pole double-zero approximation. The generalized multifrequency averaging technique is then used to analyze the lamp-ballast interaction in resonant inverters. This method was used to calculate the actual dimming range in two of the most widely used resonant configurations for a 26W compact fluorescent lamp.

Using a power-dependent small-signal model for stability analysis in resonant dimming ballasts for fluorescent lamps

Dimmable high-power-factor electronic ballast is proposed in this paper. The electronic ballast is intended to feed a 100 W electrodeless fluorescent lamp (EFL) at 250 kHz. The proposed topology consists of a buck-boost converter, as power factor correction (PFC) stage, associated with a resonant halfbridge inverter, used as lamp power control (PC) stage. In this work, the integration of both stages is proposed in order to reduce the number of active switches, as well as to simplify the required driving and control circuitry for this application. The dimming system is employed by the shared switch duty ratio control, the power variation oscillated from 100W to 44W. The implemented topology achieved a high power factor (PF), varying between 0.992 and 0.979, the line current total harmonic distortion (THD) varied from 10.016% to 6.78%, while the measured efficiency was around 80%.

Dimmable high power factor single-stage electronic ballast for electrodeless fluorescent lamps

In this paper a low-cost high-frequency power supply for ozone generation is presented Two important issues are addressed in this work: firstly, the ozone reactor is tested at high frequency and a new model of this type of load is proposed; secondly, a simple power supply stage is presented and analyzed, obtaining some important characteristics From the characteristics obtained, the correct design of the proposed power converter can easily be performed Some, simulation and experimental results are also provided to evaluate the proposed converter

http://ieeexplore.ieee.org/iel5/8625/27324/01216652.pdf

Low-power high-voltage universal-input inverter for ozone generation

The application of dimming control in high-intensity discharge (HID) lamps fed with square waveforms can influence important lamp parameters such as: lamp lifetime, efficiency, correlated color temperature (CCT), color rendering index (CRI), and others In order to study the effects of dimming control in HID lamps, this paper presents a lamp characterization study varying both lamp power and operation frequency For this purpose, metal-halide, high-pressure sodium-vapor and mercury-vapor lamps were measured

J.M. Alonso

Papers

Review of LED drivers for Visible Light Communication

Using a power-dependent small-signal model for stability analysis in resonant dimming ballasts for fluorescent lamps

Dimmable high power factor single-stage electronic ballast for electrodeless fluorescent lamps

Low-power high-voltage universal-input inverter for ozone generation

Experimental evaluation of dimming and frequency on the behavior of HID lamps fed with square waveforms