Design of a central telephone exchange

Citation: Dille, Grace. The development of the English novel. Senior thesis, Kansas State Agricultural College, 1897.Morse Department of Special CollectionsIntroduction: In designing this plant we have endeavored to meet the requirements of an up-to-date telephone exchange. With the increasing demand for the telephone, comes the necessity of improving the arrangement and the apparatus used in the exchange, to obtain quick and reliable service. Telephone men have been and are still bending all their energies in this direction. Not only is quick service an important factor, but it is of great moment to the subscriber. As the laying of cables under ground is becoming one of the necessities in large cities, we have assumed that our lines are to be layed in the best possible manner, using, only reliable conduit material, and a good grade of copper in the cables. Our purpose in using copper wire rather than iron wire is, that if at any time a change of material was desired the copper would always bring in a good return, while the iron wire would have small value. The use of copper in under ground cables cuts down depreciation to a considerable extent

Blind test comparison on the wake behind a yawed wind turbine

This article summarizes the results of the Blind test 5 workshop, which was held in Visby, Sweden, in May 2017. This study compares the numerical predictions of the wake flow behind a model wind turbine operated in yaw to experimental wind tunnel results. Prior to the workshop, research groups were invited to predict the turbine performance and wake flow properties using computational fluid dynamics (CFD) methods. For this purpose, the power, thrust, and yaw moments for a 30° yawed model turbine, as well as the wake's mean and turbulent streamwise and vertical flow components, were measured in the wind tunnel at the Norwegian University of Science and Technology (NTNU). In order to increase the complexity, a non-yawed downstream turbine was added in a second test case, while a third test case challenged the modelers with a new rotor and turbine geometry.Four participants submitted predictions using different flow solvers, three of which were based on large eddy simulations (LES) while another one used an improved delayed detached eddy simulation (IDDES) model. The performance of a single yawed turbine was fairly well predicted by all simulations, both in the first and third test cases. The scatter in the downstream turbine performance predictions in the second test case, however, was found to be significantly larger. The complex asymmetric shape of the mean streamwise and vertical velocities was generally well predicted by all the simulations for all test cases. The largest improvement with respect to previous blind tests is the good prediction of the levels of TKE in the wake, even for the complex case of yaw misalignment. These very promising results confirm the mature development stage of LES/DES simulations for wind turbine wake modeling, while competitive advantages might be obtained by faster computational methods.</p

Sediment source fingerprinting: benchmarking recent outputs, remaining challenges and emerging themes

Abstract: Purpose: This review of sediment source fingerprinting assesses the current state-of-the-art, remaining challenges and emerging themes. It combines inputs from international scientists either with track records in the approach or with expertise relevant to progressing the science. Methods: Web of Science and Google Scholar were used to review published papers spanning the period 2013–2019, inclusive, to confirm publication trends in quantities of papers by study area country and the types of tracers used. The most recent (2018–2019, inclusive) papers were also benchmarked using a methodological decision-tree published in 2017. Scope: Areas requiring further research and international consensus on methodological detail are reviewed, and these comprise spatial variability in tracers and corresponding sampling implications for end-members, temporal variability in tracers and sampling implications for end-members and target sediment, tracer conservation and knowledge-based pre-selection, the physico-chemical basis for source discrimination and dissemination of fingerprinting results to stakeholders. Emerging themes are also discussed: novel tracers, concentration-dependence for biomarkers, combining sediment fingerprinting and age-dating, applications to sediment-bound pollutants, incorporation of supportive spatial information to augment discrimination and modelling, aeolian sediment source fingerprinting, integration with process-based models and development of open-access software tools for data processing. Conclusions: The popularity of sediment source fingerprinting continues on an upward trend globally, but with this growth comes issues surrounding lack of standardisation and procedural diversity. Nonetheless, the last 2 years have also evidenced growing uptake of critical requirements for robust applications and this review is intended to signpost investigators, both old and new, towards these benchmarks and remaining research challenges for, and emerging options for different applications of, the fingerprinting approach

Using Digital Images of the Zebra Finch Song System as

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neuralsystem underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify.During development, the zebra finch song system can be altered by steroid hormones,specifically estradiol, which actually masculinizes it. Because of the ease of quantification andexperimental manipulation, the zebra finch song system has great potential for use inundergraduate labs.Unfortunately, the underlying costs prohibit use of this system in undergraduate labs. Further, thetime required to perform a developmental study renders such undertakings unrealistic within asingle academic term.We have overcome these barriers by creating digital tools, including an image library of songnuclei from zebra finch brains. Students using this library replicate and extend a publishedexperiment examining the dose of estradiol required to masculinize the female zebra finch brain.We have used this library for several terms, and students not only obtain significant experimentalresults but also make gains in understanding content, experimental controls, and inferentialstatistics (ANOVA and post-hoc tests). We have provided free access to these digital tools athttp://mdcune.psych.ucla.edu/modules/birdsong