Uncertainty Quantification in Energy Management Procedures

Complex energy systems are made up of a number of components interacting together via different energy vectors. The assessment of their performance under dynamic working conditions, where user demand and energy prices vary over time, requires a simulation tool. Regardless of the accuracy of this procedure, the uncertainty in data, obtained both by measurements or by forecasting, is usually non-negligible and requires the study of the sensitivity of results versus input data. In this work, polynomial chaos expansion technique is used to evaluate the variation of cogeneration plant performance with respect to the uncertainty of energy prices and user requests. The procedure allows to obtain this information with a much lower computational cost than that of usual Monte-Carlo approaches. Furthermore, all the tools used in this paper, which were developed in Python, are published as free and open source software.

Comparing Accuracy and Durability Effects of Jigsaw Versus Input Flood Tasks on the Recognition of Regular Past Tense /-ed/

This study investigated the effects of input flood tasks, as focused tasks, and Jigsaw tasks, as unfocused tasks, on promoting Iranian English as Foreign Language (EFL) learners’ recognition of regular past tense /-ed/ in terms of accuracy and durability. Accordingly, using a quasi-experimental study, two intact university classes including 62 participants were randomly designated to experimental and comparison groups. The participants were homogenized regarding their language and grammar proficiency levels. The experimental group was instructed through input flood tasks and the comparison group through Jigsaw tasks. Analysis of covariance (ANCOVA) analysis showed that although both groups’ mean accuracy scores were improved on the immediate posttest, the experimental group outscored the comparison group. However, the results of the delayed posttest demonstrated that whereas the comparison group maintained their accuracy level over time, the experimental group’s accuracy mean score dropped. It can be postulated that input flood tasks may promote learners’ recognition accuracy of second language forms immediately, but this effect may gradually diminish. Hence, it can be tentatively concluded that Jigsaw tasks result in more durable gains than input flood tasks. The findings imply that when the goal of grammar instruction is to achieve durable effects, unfocused tasks should be integrated with focused tasks in the syllabus.

Optimization of process parameters on commercial mild steel using taguchi technique

In the present scenario of bulk manufacturing where Metal Removal Rate (MRR), Chip Thickness Ratio (CTR) and Surface Roughness (SR) is of significant importance in manufacturing the component using CNC (computer numerical controlled) machines. Nine experiments were conducted based on orthogonal array. General linear model has been generated for all the three output parameters such as (MRR, Chip Thickness Ratio surface roughness) versus input parameters (speed, time, depth of cut). The statistical method called the analysis of variance (ANOVA) is applied to find the critical factor. The Main effects of S/N ratio values are found and plotted in the form of graph. The optimized value is found for speed, time, and depth of cut by using “MINITAB” software. By using this optimized value the efficient metal cutting can be done in commercial mild steel.

Temporal and spatial variation in strontium in a tropical river: implications for otolith chemistry analyses of fish migration

Analysis of otolith strontium isotope ratios (87Sr/86Sr) is an increasingly utilized approach for studying fish migration. We analysed surface and ground water from the Daly River catchment in the wet–dry tropics of northern Australia over 2 years. Analyses of otolith 87Sr/86Sr ratios were also conducted for freshwater sooty grunter (Hephaestus fuliginosus) and the putatively diadromous diamond mullet (Liza ordensis). Spatial variation in freshwater 87Sr/86Sr was high (range: 0.71612–0.78059), and there was strong seasonality in water 87Sr/86Sr, with highest values in the wet season. Temporal variation in water 87Sr/86Sr ratios is attributed to seasonal patterns in surface runoff from geological formations with radiogenic compositions versus input from groundwater aquifers interacting with less radiogenic formations. Temporal variation in water 87Sr/86Sr ratios precluded robust inference on movement within fresh water for both species, although movement across salinity gradients by diamond mullet was clearly identified. We conclude that temporally and spatially replicated water Sr data should be a general requisite for studies that analyse otolith Sr (87Sr/86Sr, Sr/Ca, Sr/Ba) to make inferences about fish movement and migration.

Comparison of 6 Diode and 6 Transistor Mixers Based on Analysis and Measurement

Our goal is to overview semiconductor mixers designed for good large signal performance. Twelve different mixers were compared utilizing pn diodes, bipolar transistors, and/or junction field effect transistors. The main aspect of comparison is the third-order intercept point (IP3), and both circuit analysis and measurement results have been considered. IP3 has been analyzed by the program AWR (NI AWR Design Environment) and measured by two-tone test (Keysight Technologies). We provide three ways of improvement of large signal performance: application of a diplexer at the RF port, reduction of DC currents, and exploiting a region of RF input power with infinite IP3. In addition to that, our contributions are several modifications of existing mixers and a new mixer circuit (as illustrated in the figures). It is widely believed that the slope of the third-order intermodulation product versus input power is always greater than that of the first-order product. However, measurement and analysis revealed (as illustrated in the figures) that the two lines may be parallel over a broad range of input power, thus resulting in infinite IP3. Mixer knowledge may be useful for a wide range of readers because almost every radio contains at least one mixer.

Electron-Excited Energy Dispersive X-Ray Spectrometry at High Speed and at High Resolution: Silicon Drift Detectors and Microcalorimeters

Two recent developments in X-ray spectrometer technology provide dramatic improvements in analytical capabilities that impact the frontiers of electron microscopy. Silicon drift detectors (SDD) use the same physics as silicon (lithium) energy dispersive spectrometers [Si(Li) EDS] but differ in design: only 10% of the thickness of the Si(Li) EDS with an anode area below 0.1 mm2 and a complex rear surface electrode pattern that creates a lateral internal charge collection field. The SDD equals or betters the Si(Li) EDS in most measures of performance. For output versus input count rate, the SDD exceeds the Si(Li) EDS by a factor of 5 to 10 for the same resolution. This high throughput can benefit analytical measurements that are count limited, such as X-ray mapping and trace measurements. The microcalorimeter EDS determines the X-ray energy by measuring the temperature rise in a metal absorber. Operating at 100 mK, the microcalorimeter EDS achieves resolution of 2–5 eV over a photon energy range of 200 eV to 10 keV in energy dispersive operation, eliminating most peak interference situations and providing high peak-to-background to detect low fluorescence yield peaks. Chemical bonding effects on low energy (<2 keV) peak shapes can be measured.