Where Did All the Young People Go? Can the Organizations of the State of Maine Re-Enlist Its Native Youth?

As Maine and other New England states continue to be amongst the oldest in the United States, organizations in these states continue to struggle to find and retain suitable younger replacements for their retiring leadership. As the millennia! generation continues to become a significant portion of the American workforce, learning how to connect with, recruit, and retain this generation will prove useful when leadership succession is required. By exploring how this generation was nurtured and educated, we can begin to understand ways, such as non-traditional or reverse mentoring relationships, that New England\u27s organizations can begin to recruit and retain their future leaders

Using Food Wastes in Farm-Based Anaerobic Digesters

DAIRY PRODUCERS ARE INCREASINGLY INTERESTED in mixing food wastes with animal manure as feedstock for anaerobic digesters. Anaerobic digestion (AD) is a biochemical degradation process that converts complex organic materials into biogas in the absence of oxygen. Biogas is composed of methane, carbon dioxide and trace amounts of hydrogen sulfide. Animal wastes, especially dairy manure, have proven to be ideal feedstocks for anaerobic digesters. Food wastes, mostly generated from food processing and food service, also can be excellent feedstocks for AD. Food wastes typically have high ratios of volatile solids-to-total solids (80 – 90%), which indicate high energy content. The volatile solids are the fraction of total solids that can potentially be converted into biogas

The Difficulty of Getting High Escape Fractions of Ionizing Photons from High-redshift Galaxies: a View from the FIRE Cosmological Simulations

We present a series of high-resolution (20-2000 Msun, 0.1-4 pc) cosmological zoom-in simulations at z~6 from the Feedback In Realistic Environment (FIRE) project. These simulations cover halo masses 10^9-10^11 Msun and rest-frame ultraviolet magnitude Muv = -9 to -19. These simulations include explicit models of the multi-phase ISM, star formation, and stellar feedback, which produce reasonable galaxy properties at z = 0-6. We post-process the snapshots with a radiative transfer code to evaluate the escape fraction (fesc) of hydrogen ionizing photons. We find that the instantaneous fesc has large time variability (0.01%-20%), while the time-averaged fesc over long time-scales generally remains ~5%, considerably lower than the estimate in many reionization models. We find no strong dependence of fesc on galaxy mass or redshift. In our simulations, the intrinsic ionizing photon budgets are dominated by stellar populations younger than 3 Myr, which tend to be buried in dense birth clouds. The escaping photons mostly come from populations between 3-10 Myr, whose birth clouds have been largely cleared by stellar feedback. However, these populations only contribute a small fraction of intrinsic ionizing photon budgets according to standard stellar population models. We show that fesc can be boosted to high values, if stellar populations older than 3 Myr produce more ionizing photons than standard stellar population models (as motivated by, e.g., models including binaries). By contrast, runaway stars with velocities suggested by observations can enhance fesc by only a small fraction. We show that "sub-grid" star formation models, which do not explicitly resolve star formation in dense clouds with n >> 1 cm^-3, will dramatically over-predict fesc.Comment: 17 pages, 16 figures, MNRAS in pres

Evidence of an advantage in visuo-spatial memory for bilingual compared to monolingual speakers

Previous research has indicated that bilinguals outperform monolinguals in cognitive tasks involving spatial working memory. The present study examines evidence for this claim using a different and arguably more ecologically valid method (the change blindness task). Bilingual and monolingual participants were presented with two versions of the same scenes and required to press a key as soon as they identified the alteration. They also completed the word and alpha span tasks, and the Corsi blocks task. The results in the change blindness task, controlled for group differences in non-verbal reasoning, indicated that bilinguals were faster and more accurate than monolinguals at detecting visual changes. Similar group differences were found on the Corsi block task. Unlike previous findings, no group differences were found on the verbal memory tasks. The results are discussed with reference to mechanisms of cognitive control as a locus of transfer between bilingualism and spatial working memory tasks

Modeling software artifact count attribute with s-curves

The estimation of software project attributes, such as size, is important for software project resource planning and process control. However, research regarding software attribute modeling, such as size, effort, and cost, are high-level and static in nature. This research defines a new operation-level software project attribute that describes the operational characteristic of a software project. The result is a measurement based on the s-curve parameter that can be used as a control variable for software project management. This result is derived from modeling the count of artifact instances created by the software engineering process, which are stored by software tools. Because of the orthogonal origin of this attribute in regard to traditional static estimators, this s-curve based software attribute can function as an additional indicator of software project activities and also as a quantitative metric for assessing development team capability

Formation of Globular Cluster Candidates in Merging Proto-galaxies at High Redshift: A View from the FIRE Cosmological Simulations

Using a state-of-the-art cosmological simulation of merging proto-galaxies at high redshift from the FIRE project, with explicit treatments of star formation and stellar feedback in the interstellar medium, we investigate the formation of star clusters and examine one of the formation hypothesis of present-day metal-poor globular clusters. We find that frequent mergers in high-redshift proto-galaxies could provide a fertile environment to produce long-lasting bound star clusters. The violent merger event disturbs the gravitational potential and pushes a large gas mass of ~> 1e5-6 Msun collectively to high density, at which point it rapidly turns into stars before stellar feedback can stop star formation. The high dynamic range of the reported simulation is critical in realizing such dense star-forming clouds with a small dynamical timescale, t_ff <~ 3 Myr, shorter than most stellar feedback timescales. Our simulation then allows us to trace how clusters could become virialized and tightly-bound to survive for up to ~420 Myr till the end of the simulation. Because the cluster's tightly-bound core was formed in one short burst, and the nearby older stars originally grouped with the cluster tend to be preferentially removed, at the end of the simulation the cluster has a small age spread.Comment: 14 pages, 14 figures, Accepted for publication in the Monthly Notices of the Royal Astronomical Society, High-resolution version of this article also available at http://www.jihoonkim.org/index/research.html#g

Demonstration system of pumped heat energy storage (PHES) and its round-trip efficiency

Among the known energy storage technologies aiming to increase the efficiency and stability of power grids, Pumped Heat Energy Storage (PHES) is considered by many as a promising candidate because of its flexibility, potential for scale-up and low cost per energy storage unit. Whilst there are numerous demonstration systems under development, as it stands the only PHES demonstration system to be realised at scale is located in Hampshire, UK. This paper aims to present the results and analysis obtained from its commissioning and testing as part of an on-going study. The system was designed to offer a nominal power size of 150 kWe and energy storage capacity of 600 kWhe for an 8-hour storage cycle. This work presents evidence of the system Round-trip efficiency (RTE), which is considered as a fundamental performance metric for large-scale energy storage technologies. Recorded Pressure-Volume (P-V) measurements from recent heat pump/engine testing at part-load offers useful insight in terms of overall performance. Models are also developed to simulate the system to finally predict the performance at full-load conditions. The system and principle of operation are described first, followed by mathematical modelling outlining heat transfer mechanism and associated key losses involved in thermodynamic processes within components, and finally results are presented and compared at different operating conditions using different working gases. The results show good agreement with earlier studies, which indicate that expected electricity-to-electricity RTE is quite comparable to other mature technologies such as Pumped Hydropower Storage and Compressed Air Energy Storage. The cyclic operation of the system is also discussed. One-off storage cycle results in lower RTEs compared to a load-levelling cyclic operation where the efficiency is significantly improved due to stable packed-bed behaviour and better utilisation after an initial transient state

Making Sense of Audio Vibration for Liquid Height Estimation in Robotic Pouring

In this paper, we focus on the challenging perception problem in robotic pouring. Most of the existing approaches either leverage visual or haptic information. However, these techniques may suffer from poor generalization performances on opaque containers or concerning measuring precision. To tackle these drawbacks, we propose to make use of audio vibration sensing and design a deep neural network PouringNet to predict the liquid height from the audio fragment during the robotic pouring task. PouringNet is trained on our collected real-world pouring dataset with multimodal sensing data, which contains more than 3000 recordings of audio, force feedback, video and trajectory data of the human hand that performs the pouring task. Each record represents a complete pouring procedure. We conduct several evaluations on PouringNet with our dataset and robotic hardware. The results demonstrate that our PouringNet generalizes well across different liquid containers, positions of the audio receiver, initial liquid heights and types of liquid, and facilitates a more robust and accurate audio-based perception for robotic pouring.Comment: Checkout project page for video, code and dataset: https://lianghongzhuo.github.io/AudioPourin