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

In this paper the design, implementation and experimental results of a high-voltage power supply for ozone generation are presented The power stage is formed by a buck converter plus a current-fed parallel-resonant push-pull inverter The buck converter is used to both regulate the output power against the line voltage variation, and to control the power delivered to the ozone generator (OG) The push-pull inverter assures safe operation of the OG by working at the parallel resonant frequency given by the high-voltage transformer plus OG characteristic In this paper, the closed-loop operation of the proposed converter is analyzed and implemented as a method to compensate variations in the line voltage and in the OG A low cost commercial UC3872 integrated circuit is used to control both the push-pull inverter and the buck converter, providing OG power control and regulation via buck converter duty cycle Protections against short circuit and no load operation are also implemented Experimental results for a 100W prototype are shown and discussed

http://ieeexplore.ieee.org/iel5/5254890/5278662/05278749.pdf

Closed-loop regulated power supply for ozone generation based on buck converter and current-fed push-pull resonant inverter

Dimming application in high intensity discharge (HID) lamps can affect several lamp parameters such as: lamp life, power factor, color temperature, discharge arc path, among other effects. With the purpose of analyzing the dimming in HID Lamps, a comparative analysis of dimming effects in metal halide and high pressure sodium (HPS) lamps is presented in this paper. With this purpose, several lamps were characterized and electrical models were developed for their simulation in PSpice.

Dimming in metal-halide and HPS lamps operating at HF: effects and modeling

In this paper, the design and construction of an electronic ballast based on a class E amplifier with a capacitive impedance inverter and with dimming features is presented. The ballast is intended to supply instant-start fluorescent lamps from a DC 12 V source. The use of class E amplifiers in fluorescent lamps ballasts presents large advantages such as: high power density; simple structure (only one transistor); high efficiency; and optimum lamp driving. The class E amplifier uses a capacitive impedance inverter as the resonant tank and one diode in antiparallel with the switch; these elements allow the implementation of a dimming feature for the ballast. One of the main applications of this ballast is the supply of fluorescent lamps from solar cells. The design process has been simplified obtaining several characteristics and using mathematical programs. The designed electronic ballast drives a 21 W lamp and operates at a switching frequency of 400 kHz. Dimming is implemented using a SG3524 in a VCO fashion.

Electronic ballast based on class E amplifier with a capacitive inverter and dimming for photovoltaic applications

This paper presents some design issues and experimental results regarding the use of the input current shaper (ICS) technique to implement high power factor electronic ballasts. The ICS is placed between main rectifier and bulk capacitor to increase the conduction angle of the main rectifier diodes up to a minimum value to obtain low current harmonics injected to the mains. Two possibilities to implement ICS-based ballast are considered in this paper: the forward-based ICS and the flyback-based ICS. Experimental results obtained from two 40 W fluorescent lamp ballasts are also presented.

http://ieeexplore.ieee.org/iel5/6470/17346/00799967.pdf

Design and experimental results of an input-current-shaper based electronic ballast

The diagnosis of smoldering multiple myeloma (SMM) includes patients with a heterogeneous risk of progression to active multiple myeloma (MM): some patients will never progress, whereas others will have a high risk of progression within the first 2 years. Therefore, it is important to improve risk assessment at diagnosis. We conducted a retrospective study in a large cohort of SMM patients, in order to investigate the role of Bence Jones (BJ) proteinuria at diagnosis in the progression to active MM. We found that SMM patients presenting with BJ proteinuria had a significantly shorter median time to progression (TTP) to MM compared with patients without BJ proteinuria (22 vs 88 months, respectively; hazard ratio=2.3, 95% confidence interval=1.4-3.9, P=0.002). We also identified risk subgroups based on the amount of BJ proteinuria: ⩾500 mg/24 h, <500 mg/24 h and without it, with a significantly different median TTP (13, 37 and 88 months, P<0.001). Thus, BJ proteinuria at diagnosis is an independent variable of progression to MM that identifies a subgroup of high-risk SMM patients (51% risk of progression at 2 years) and ⩾500 mg of BJ proteinuria may allow, if validated in another series, to reclassify these patients to MM requiring therapy before the end-organ damage development.

J.M. Alonso

Papers

Closed-loop regulated power supply for ozone generation based on buck converter and current-fed push-pull resonant inverter

Dimming in metal-halide and HPS lamps operating at HF: effects and modeling

Electronic ballast based on class E amplifier with a capacitive inverter and dimming for photovoltaic applications

Design and experimental results of an input-current-shaper based electronic ballast

Bence Jones proteinuria in smoldering multiple myeloma as a predictor marker of progression to symptomatic multiple myeloma.