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The distribution of large conjugative Haemophilus influenzae plasmids in the nasopharyngeal haemophili of a group of people and in a large collection of 541 H. influenzae type b (Hib) isolates was studied. A newly developed PCR-based assay was used to detect the plasmids. The target sequences were chosen from sequence analysis of part of p1056, a large multiresistance plasmid isolated from a clinical Hib isolate, 1056. Fifty-nine per cent of people were found to carry β-lactamase-positive (β-lac+), ampicillin-resistant (ampR) haemophili with detectable plasmid sequences. Of these, 83% were in Haemophilus parainfluenzae and 17% were in H. influenzae. In the collection of 541 Hib, antibiotic resistance [β-lac+ampR, β-lac+ampR plus tetracycline resistance (tetR) or tetR] was highly correlated with large plasmids. It was found that 2.3% of the isolates contained large cryptic plasmids (i.e. these isolates were susceptible to antibiotics). The distribution of plasmids between invasive and carried Hib did not differ significantly (25 of 245 and 23 of 276, respectively). Isolates with large plasmids occur at high frequency in the nasopharynx of the normal human population and consist of two populations in Hib, one associated with specific antibiotic resistance traits and the other cryptic. These plasmids do not appear to influence the invasiveness of Hib. [ABSTRACT FROM PUBLISHER]

eSolar provides a low-cost, modular heliostat field solution for tower-based CSP facilities. Industry-leading cost has been achieved via large quantities of small (∼2.2 m2) single-facet, individually-controlled heliostats with simple field installation methods. These modular fields can contain up to 50,000 heliostats (108,000 m2) per receiver and a dozen or more modules may comprise a single plant, presenting a challenge for timely commissioning and calibration with previously existing technology. In response to this challenge, eSolar has developed a fully-automated proprietary calibration system that enables accurate individual heliostat tracking rapidly upon commissioning. The system operates by reflecting light from LEDs located on towers around the field into cameras, which are located on the same towers. The efficacy of this approach is demonstrated at eSolar's Sierra SunTower facility in Lancaster, CA, USA (Fig. 1) where a field of >24,000 heliostats can be calibrated from realistic seed conditions in less than two weeks with resultant pointing error of <1.5 mrad. The calibration system's precise, parallel, and high throughput data collection further enables rapid detection of broken and mis-pointing heliostats, dramatically reducing the Mean Time to Repair (MTTR) from individual heliostat failures, as well as automating the task of discovering such failures. This paper describes the technical solution that eSolar has created and elaborates on the benefits of the system. [ABSTRACT FROM AUTHOR]

The long term success of the concentrating solar power (CSP) industry depends on having accurate and reliable measurements and predictions of performance. Agreed-upon standards for performance characterization are still lacking. This contrasts with more mature technologies such as gas turbine combined cycle power plants, where performance and testing specifications are well established in spite of system complexities. Lack of standardization inevitably results in extra cost and risk to market participants and the spread of misinformation through hidden “apples-to-oranges” comparisons. To cite just one example, there are multiple distinct metrics for characterizing heliostat tracking accuracy, and the differences can easily go unnoticed. Here we propose rigorous and accurate statistical approaches to two key performance analysis problems for tower CSP. We highlight their advantages over previous approaches, and analyze detailed operational data. Further, we demonstrate why they are sufficiently straightforward and general enough for adoption as industry standards. [ABSTRACT FROM AUTHOR]

Abstract: eSolar has been designing small heliostats since the company's founding in 2007. One of the cornerstones of our approach to heliostat design is to deploy many factory-built small heliostats in high density fields. The fields are replicated and thus aggregated into solar plants supporting steam and molten salt electric power, integrated solar combined cycle (ISCC), and process heat applications, such as enhanced oil recovery and desalination. The small heliostat approach has been used in several pilot projects and was previously evolved into a commercially available product presented in 2011 at SolarPACES. In this paper we discuss the ground up redesign of our small heliostat hardware, with a focus of leveraging the proven approach into a higher reliability, globally applicable, more industrial, simple to source and most importantly total installed cost reduced solar collector product. During the redesign we discovered methods to simplify the design and confirmed that small, factory-built, affordable heliostats provide a compelling concentrated solar thermal technology. We discuss details on system optimization, concept selection and prototype development, including some results from design validation testing. Finally, we discuss how this new solar collector system (SCS5) performs and meets economic requirements. eSolar's SCS5 product will be commercially released early in 2014, and is currently available to quote for CSP projects. [Copyright &y& Elsevier]