Elgaria panamintina

Number of Pages: 4Integrative BiologyGeological Science

The Close Binary Fraction of Dwarf M Stars

We describe a search for close spectroscopic dwarf M star binaries using data from the Sloan Digital Sky Survey to address the question of the rate of occurrence of multiplicity in M dwarfs. We use a template-fitting technique to measure radial velocities from 145,888 individual spectra obtained for a magnitude-limited sample of 39,543 M dwarfs. Typically, the three or four spectra observed for each star are separated in time by less than four hours, but for ~17% of the stars, the individual observations span more than two days. In these cases we are sensitive to large-amplitude radial velocity variations on timescales comparable to the separation between the observations. We use a control sample of objects having observations taken within a four-hour period to make an empirical estimate of the underlying radial velocity error distribution and simulate our detection efficiency for a wide range of binary star systems. We find the frequency of binaries among the dwarf M stars with a < 0.4 AU to be 3%-4%. Comparison with other samples of binary stars demonstrates that the close binary fraction, like the total binary fraction, is an increasing function of primary mass

Opportunities for Stationary Fuel Cell Applications in Ohio: Public Finance and Other Strategies

Ohio has not, heretofore, been a major player in the deployment of stationary fuel cell applications, notwithstanding its status as a leader in developing fuel cell technology. One reason for this is that in the years since fuel cells became commercially available, fuel cell power generation had struggled to be cost effective in Ohio due to a combination low electricity prices and high natural gas prices, the latter being the most common fuel for stationary fuel cell applications. By 2015, this had changed. The Mid-Atlantic region was enjoying the lowest natural gas prices in North America as a result of regional shale development. Meanwhile, wholesale electricity prices in the PJM Interconnect regional transmission organization (Mid-Atlantic region) are among the highest in the nation. This has created therein a historically high “spark spread” -- the term used to describe the price differential between wholesale natural gas and electricity. What’s more, fuel cell generation qualifies for net metering, and may be valued at retail costs. Finally, additional new value for the avoided costs of carbon and other emissions may be derived from new ultra-efficient fuel cell technologies. As for other nascent technologies, early adoption will likely require public-private financing partnerships. There are available federal, state and local financing strategies to enable the deployment of fuel cells in Ohio. Loan programs such as the Energy Loan Fund and Qualified Energy Conservation Bonds can be used to support fuel cell demonstration with low interest loans. Property Assessed Clean Energy (PACE) bonds may also soon be available to support fuel cell deployment, depending upon pending Ohio legislation. In addition, the Public Utility Commission of Ohio has within its authority to support power purchase agreements or special arrangements for buyers to support generation that is in the interest of Ohio ratepayers (such as when it promotes economic development). The best places to acquire natural gas for power generation on long-term, fixed prices will be at gathering points along the natural gas pipeline and processing system. Such points offer natural gas producers the most flexibility to supply natural gas long term. Most of the gathering and processing points are currently located in southeastern Ohio, however new interstate pipelines are being built across northern Ohio. This new infrastructure may provide opportunities to locate stationary fuel cells in the generation, transmission and capacity-constrained northern Ohio market. Low gas prices may also provide opportunities for stationary fuel cell applications using low temperature fuel cells. Such fuel cells run directly on hydrogen, and heretofore, the costs of manufacturing, transporting and storing hydrogen has made the economics for such generation difficult. Low hydrogen feedstock costs, together with the ability low temperature fuel cells have to supply the lucrative peak loading market, may make such applications cost effective in the near term

Linear Self-Motion Cues Support the Spatial Distribution and Stability of Hippocampal Place Cells

The vestibular system provides a crucial component of place-cell and head-direction cell activity [1-7]. Otolith signals are necessary for head-direction signal stability and associated behavior [8, 9], and the head-direction signal's contribution to parahippocampal spatial representations [10-14] suggests that place cells may also require otolithic information. Here, we demonstrate that self-movement information from the otolith organs is necessary for the development of stable place fields within and across sessions. Place cells in otoconia-deficient tilted mice showed reduced spatial coherence and formed place fields that were located closer to environmental boundaries, relative to those of control mice. These differences reveal an important otolithic contribution to place-cell functioning and provide insight into the cognitive deficits associated with otolith dysfunction

The distance and neutral environment of the massive stellar cluster Westerlund 1

The goal of this study is to determine a distance to Westerlund 1 independent of the characteristics of the stellar population and to study its neutral environment, using observations of atomic hydrogen. The HI observations are taken from the Southern Galactic Plane Survey to study HI absorption in the direction of the HII region created by the members of Westerlund 1 and to investigate its environment as observed in the HI line emission. A Galactic rotation curve was derived using the recently revised values for the Galactic centre distance of $R_\odot = 7.6$ kpc, and the velocity of the Sun around the Galactic centre of $\Theta_\odot = 214$ km s$^{-1}$. The newly determined rotation model leads us to derive a distance of $3.9\pm 0.7$ kpc to Westerlund 1, consistent with a location in the Scutum-Crux Arm. Included in this estimate is a very careful investigation of possible sources of error for the Galactic rotation curve. We also report on small expanding HI features around the cluster with a maximum dynamic age of 600,000 years and a larger bubble which has a minimum dynamic age of 2.5 million years. Additionally we re-calculated the kinematic distances to nearby HII regions and supernova remnants based on our new Galaxic rotation curve. We propose that in the early stages of the development of Wd 1 a large interstellar bubble of diameter about 50 pc was created by the cluster members. This bubble has a dynamic age similar to the age of the cluster. Small expanding bubbles, with dynamical ages $\sim 0.6$ Myr are found around Wd 1, which we suggest consist of recombined material lost by cluster members through their winds.Comment: 8 pages, accepted for publication in A&

Mapping Theoretical and Methodological Perspectives for Understanding Speech Interface Interactions

CHI 2019: The ACM CHI Conference on Human Factors in Computing Systems - Weaving the Threads of CHI, Glasgow, United Kingdom, 4-9 May 2019The use of speech as an interaction modality has grown considerably through the integration of Intelligent Personal Assistants (IPAs- e.g. Siri, Google Assistant) into smartphones and voice based devices (e.g. Amazon Echo). However, there remain significant gaps in using theoretical frameworks to understand user behaviours and choices and how they may applied to specific speech interface interactions. This part-day multidisciplinary workshop aims to critically map out and evaluate the- oretical frameworks and methodological approaches across a number of disciplines and establish directions for new paradigms in understanding speech interface user behaviour. In doing so, we will bring together participants from HCI and other speech related domains to establish a cohesive, diverse and collaborative community of researchers from academia and industry with interest in exploring theoretical and methodological issues in the field.Irish Research Counci

Generation of 3-Dimensional graph state with Josephson charge qubits

On the basis of generations of 1-dimensional and 2-dimensional graph states, we generate a 3-dimensional N3-qubit graph state based on the Josephson charge qubits. Since any two charge qubits can be selectively and effectively coupled by a common inductance, the controlled phase transform between any two-qubit can be performed. Accordingly, we can generate arbitrary multi-qubit graph states corresponding to arbitrary shape graph, which meet the expectations of various quantum information processing schemes. All the devices in the scheme are well within the current technology. It is a simple, scalable and feasible scheme for the generation of various graph states based on the Josephson charge qubits.Comment: 4 pages, 4 figure

What Do We See in Them? Identifying Dimensions of Partner Models for Speech Interfaces Using a Psycholexical Approach

Perceptions of system competence and communicative ability, termed partner models, play a significant role in speech interface interaction. Yet we do not know what the core dimensions of this concept are. Taking a psycholexical approach, our paper is the first to identify the key dimensions that define partner models in speech agent interaction. Through a repertory grid study (N=21), a review of key subjective questionnaires, an expert review of resulting word pairs and an online study of 356 users of speech interfaces, we identify three key dimensions that make up a users’ partner model: 1) perceptions towards partner competence and dependability; 2) assessment of human-likeness; and 3) a system’s perceived cognitive flexibility. We discuss the implications for partner modelling as a concept, emphasising the importance of salience and the dynamic nature of these perceptions

Fatigue Testing a Mechanized Percussion Well Drilling System for Water Access in Western Africa

The Mechanized Percussion Well Drilling (MPWD) Collaboratory project seeks to design a simple mechanized well drilling system for drilling shallow water wells in Western Africa. Our client, Open Door Development (ODD), seeks to make water accessible to all in the region, but has had difficulty drilling through hard soil layers. To combat this problem, the MPWD team has worked closely with Mr. Joseph Longenecker to develop a mechanized percussion well drilling rig that is capable of drilling through these harder layers. Currently, the MPWD team is seeking to provide recommendations to improve the lifetime of our client’s new, fully mechanized rig design. This year, our team’s work has been focused specifically on analyzing the lifetime of the rig’s driveline chains and also on its frame. For the driveline chains, the team will be conducting fatigue testing on a model of the driveline system to determine which type of chain should be used on the rig. To determine the lifetime of the frame, the team will be performing a series of static, buckling, and fatigue finite element analyses on the rig’s frame. The most recent accomplishments of the MPWD team have nearly proved that their design for the loading application will be feasible for use on the actual testing rig and that multiple studies of finite element analysis can be performed to simulate the different rig frame loading scenarios.https://mosaic.messiah.edu/engr2021/1019/thumbnail.jp