Assessing the level of confidence for expressing extended uncertainty: a model based on control errors in the measurement of ion activity

<p>A method for estimating the level of confidence when determining the coverage factor based on control errors is proposed, using the example of measurements of ion activity. Using information on tolerances and uncertainty, it is possible to establish a reasonable interval around the measurement result, within which most of the values that can be justified are assigned to the measured value.</p>

Reference materials for optic nanosensor systems: reduced glutathione and chloramphenicol

The research provides enterprise reference material (ERM) development approach for nanosensor system on the basis of dynamic light scattering and fluorescence for qualitative and quantitative determination of nutrition pollutant - chloramphenicol antibiotic (laevomycetin), as well as marker of ischaemic stroke and a number of other diseases - reduced glutathione.ERM candidate materials were chosen chloramphenicol and reduced glutathione. The attestation procedure based on calculating-experimental approach by preparation procedure was used to determine the certified value of ERM. During the tests there were determined metrological characteristics of reference material. The certified value of ERM for reduced glutathione mass fraction is 98,5 %, the expanded uncertainty of certified value with coverage factor k=2 is ± 0,3 %. The certified value of ERM for chloramphenicol mass concentration is 10,0 g/dm3, the expanded uncertainty of certified value with coverage factor k = 2 is ± 4,0 %.The implementation of the developed ERMs showed their appropriateness for optic nanosensor systems calibration on the base of dynamic light scattering and fluorescence.We suppose that the developed enterprise reference materials further may be certified as CRM (certified reference material) and used for verification, calibration and graduation of compact detection devices of the «point of care diagnostics» type under development, which are intended for express analysis on the sampling site directly.

Optical Fiber Time Delay Comparison Between NIST and LAMETRO

We describe the results of a bilateral measurement comparison of optical fiber time delay between the National Institute of Standards and Technology (NIST, USA) and Laboratorio de Metrología, Instituto Costarricense de Electricidad (LAMETRO-ICE, Costa Rica), which was conducted on a single-mode optical fiber reference spool at wavelengths of 1310 nm and 1550 nm. The measurement results showed the largest difference to be less than 0.93 ns, which is within the combined standard uncertainty (coverage factor k = 1) for the measurement systems at the two laboratories.

Copula based Measures of Repairable Parallel System with Fault Coverage

The main objective of this study is to analyse the reliability behaviour of parallel systems with three types of failure, namely unit failure, human failure and major failure. For this purpose, we apply three different statistical techniques, namely copula, coverage and copula-coverage. More precisely, this study presents a stochastic model for analysing the behaviour of a multi-state system consisting of two non-identical units by incorporating the concept of coverage factor and two types of repair facilities between failed state to a normal state. The system could be characterized as being in a failed state due to unit failures, human failure and major failures, such as catastrophic and environmental failure. All failure rates are constant and it is assumed that these are exponentially distributed whereas, repair rates follow the Gumbel-Hougaard copula distribution. The entire system is modelled as a finite-state Markov process. Time-dependent reliability measures like availability, reliability and mean time to failure (MTTF) are obtained by supplementary variable techniques and Laplace transformations. The present study provides a comparative analysis for reliability measures among the aforementioned techniques, while a discussion referring to which technique makes the system more reliable is also developed. Furthermore, numerical simulations are presented to validate the analytical results.

A Powdered Simulant of Triacetone Triperoxide (TATP) for Safe Testing of X-ray Transmission Screening Equipment

Explosives detection systems (EDS) based on X-ray are used at airports to screen baggage for the presence of explosives. Once EDS are installed in airports, however, it can be challenging to test the EDS equipment and verify that it continues to perform at the highest level, because of the impracticality of introducing bulk explosives into civil aviation airports. The problem is particularly acute for sensitive homemade explosives, such as triacetone triperoxide (TATP). This paper describes our work to develop a safe, accurate and stable simulant for TATP for EDS based on X-ray transmission. Bulk quantities of TATP were synthesised and characterised especially for this project, and we describe the unique challenges and safety considerations of collecting this data. Our calculations show that the expanded measurement uncertainty with a coverage factor of k = 2 is 5.7% for bulk density and 1.0% for Zeff at 24 months.

Optimization of Fixed PV Panel “Tilt” Angles for Maximal Energy Harvest Considering Year-Around Sky Coverage Conditions

In order to maximize the electrical energy harvested by photovoltaic panels in a setup with fixed angles, it is important to get the angle optimized. In the present work, sunlight availability or sky coverage conditions of year-long period based on ten years’ data are counted in the modeling to optimize the PV panel tilt angles targeting for the maximal energy in a year. The analysis uses precise sunray calculation models. The energy harvested in every 6 minutes by a PV panel is summated for the daily time period from sunrise to sunset when the sun elevation angles are above 5 degree, with the sky-coverage factor multiplied. The results show that the annual solar energy received by a PV solar panel tilted with a fixed angle equal to the local latitude (at Tucson AZ, USA) could reach 2297 kWh/m2 under 10-year averaged sky coverage conditions. However, the gain in the yearly solar energy harvest is expected to be about 4.28%, 7.06%, and 8.42% higher if a PV panel is inclined optimally according to two-season, four-season, and monthly adjustments, respectively, compared to the optimized life-long fixed angle.

Evaluating Changes to Prevented Planting Provision on Moral Hazard

Prevented planting provision in crop insurance protects producers from failure to plant attributable to natural causes. We determined the impact of this provision at various crop insurance coverage levels on prevented planting claims and ex post moral hazard. The moral hazard incentive in the prevented planting provision is stronger for corn than soybeans. Reducing the prevented planting coverage factor for corn could likely reduce moral hazard, but the degree of the reduction will likely depend on the revenue protection coverage level. Conversely, we found moral hazard is unlikely to occur for soybean production regardless of the revenue protection coverage level.