High-sensitivity photoacoustic leak testing

The photoacoustic effect may be exploited for the detection and localization of gas leaks from otherwise sealed components. The technique involves filling the test component with a tracer gas, and radiating the component to produce photoacoustic sound from any leak site where tracer gas is present. This paper describes demonstration experiments utilizing 10.6-µ radiation from a carbon-dioxide laser and sulfur hexafluoride as a tracer gas for photoacoustic leak testing at leak rates between 6×10–5 cm3/s (1 cm3 in 4.6 h) and 5×10–9 cm3/s (1 cm3 in 6.3 years). The technique may reach or exceed the capabilities of the most sensitive commercial leak test systems using helium mass-spectrometers. In addition, comparison of the measured results to a simple scaling law suggests that tracer gas cloud geometry influences the photoacoustic signal amplitude

Pavement Evaluation of the Concrete Tie-bars and Dowel Baskets on Irvin Cobb Drive, US 60, McCracken County, KY

A 1500 Mhz. ground coupled, ground penetrating radar antenna was used to identify both the horizontal alignment and the vertical displacement of the concrete tie-bars and the transverse joint dowel bar assembles on a Portland-Cement-Concrete-Pavement (PCCP) on US 60 in McCracken County, KY. Approximately 5 lanes miles of PCCP were evaluated using the 1500 Mhz. ground coupled antenna. Results indicate that only one transverse dowel basket out of an approximate total of 1,760 were within 4.17 inches of the pavement surface. Seven transverse dowel baskets were misaligned four inches or greater from the location of the sawed joint. These areas represent 0.45 percent of the total transverse joints on the project. The ground penetrating radar results also indicated there were no areas along the longitudinal joint where the tie-bars were either too close to the pavement surface or missing

Unhiding the audiovisual past at Columbia University Libraries

As part of a larger hidden collections initiative, Columbia University Libraries initiated plans in 2018 to digitize their unique audiovisual holdings over seven years. In order to meet an ambitious target within a limited timeframe, staff across divisions and departments had to collaboratively develop shared workflows and efficiencies to maximize output while ensuring a high level of quality. Due to the unique challenges of working with audio and video collections, this collaborative effort was truly unprecedented in the history of Columbia Libraries. This project represented an excellent opportunity to test new functionalities of our locally developed digital asset management system Hyacinth and find robust methods to improve digital curation and preservation using tools like Archivematica digital preservation system. The scope of the project required that we develop efficiencies in our cataloging and metadata enhancement workflows including task automation in OpenRefine, sync metadata between systems including our Voyager ILS and Hyacinth, and plan for new initiatives such as the implementation of a rights management module and integration of crosswalks to ArchivesSpace. One additional outcome of the project’s first year is a deeper analysis of project statistics and workflows using project management methods to inform the future development and planning of the project for years 2-7. This presentation will examine the development of these shared workflows across curatorial, preservation, metadata, and digital technology units, challenges overcome, and lessons learned

Future Proof: Preserving and Providing Access to Columbia's Audio Visual Collections

As part of a larger hidden collections initiative, in 2018, Columbia University Libraries embarked on a seven year project to digitize their unique audiovisual holdings. In order to meet an ambitious target within a limited timeframe, staff across divisions and departments had to collaboratively develop shared workflows and efficiencies to maximize output while ensuring a high level of quality. Due to the unique challenges of working with analog film/video collections, this collaborative effort was truly unprecedented in the history of Columbia Libraries. This project represented an excellent opportunity to test new functionalities of our locally developed digital asset management system Hyacinth and find robust methods to improve digital curation and preservation using tools like Archivematica digital preservation system. The scope of the project required that we develop efficiencies in our cataloging and metadata enhancement workflows including task automation in OpenRefine, sync both published and unpublished metadata between systems including our Voyager ILS and Hyacinth, and plan for an exponential increase in how digital media collections would be used by both patrons and staff. This presentation will examine the development, implementation, and lessons learned of these cross-departmental workflows as they pertain to the complex landscape of large-scale digital media preservation and access within research libraries

Making Software into a Program: Columbia University Libraries' Hyacinth User Group

This presentation, delivered at the 2019 meeting of the Digital Library Forum, highlights the work of the Hyacinth User Group at Columbia University Libraries. The group has members from many divisions of the library including Application Development, Cataloging, Digital Collections, Institutional Repository and Digital Conversion. These staff members have come together to administer Hyacinth, Columbia’s metadata and content management application. This presentation focuses on two case studies that show the value such an administrative group can bring to the shared use of software - implementing relatedness statements and managing controlled vocabularies. In the case of relatedness statements, the group navigated the varied expressions of relatedness required by different library divisions avoiding collisions and blocks to future development. Shared management of controlled vocabularies has required the group to produce robust documentation and develop clear user permissions to prevent alteration of terms as well as a remediation process for safely removing erroneous terms from the system and records. In the pursuit of these projects, we have seen the vital need for software developers and metadata practitioners to work together. Each has a unique perspective of the problems at hand. The developers have created a powerful tool to organize and publish metadata to numerous websites and digital collections. The Hyacinth User Group has developed the policies and communication flows to ensure the application’s diverse group of users can wield that tool effectively and efficiently

Quantitative optical mapping of two-dimensional materials

The pace of two-dimensional materials (2DM) research has been greatly accelerated by the ability to identify exfoliated thicknesses down to a monolayer from their optical contrast. Since this process requires time-consuming and error-prone manual assignment to avoid false-positives from image features with similar contrast, efforts towards fast and reliable automated assignments schemes is essential. We show that by modelling the expected 2DM contrast in digitally captured images, we can automatically identify candidate regions of 2DM. More importantly, we show a computationally-light machine vision strategy for eliminating false-positives from this set of 2DM candidates through the combined use of binary thresholding, opening and closing filters, and shape-analysis from edge detection. Calculation of data pyramids for arbitrarily high-resolution optical coverage maps of two-dimensional materials produced in this way allows the real-time presentation and processing of this image data in a zoomable interface, enabling large datasets to be explored and analysed with ease. The result is that a standard optical microscope with CCD camera can be used as an analysis tool able to accurately determine the coverage, residue/contamination concentration, and layer number for a wide range of presented 2DMs

Stellar multiplicity: an interdisciplinary nexus

Our uncertainties about binary star systems (and triples and so on) limit our capabilities in literally every single one of the Thematic Areas identified for Astro2020. We need to understand the population statistics of stellar multiplicity and their variations with stellar type, chemistry, and dynamical environment: Correct interpretation of any exoplanet experiment depends on proper treatment of resolved and unresolved binaries; stellar multiplicity is a direct outcome of star and companion formation; the most precise constraints on stellar structure come from well-characterized binary systems; stellar populations heavily rely on stellar and binary evolution modeling; high-redshift galaxy radiation and reionization is controlled by binary-dependent stellar physics; compact objects are the outcomes of binary evolution; the interpretation of multi-messenger astronomy from gravitational waves, light, and neutrinos relies on understanding the products of binary star evolution; near-Universe constraints on the Hubble constant with Type Ia supernovae and gravitational-wave mergers are subject to systematics related to their binary star progenitors; local measures of dark-matter substructure masses are distorted by binary populations. In order to realize the scientific goals in each of these themes over the next decade, we therefore need to understand how binary stars and stellar multiplets are formed and distributed in the space of masses, composition, age, and orbital properties, and how the distribution evolves with time. This white paper emphasizes the interdisciplinary importance of binary-star science and advocates that coordinated investment from all astrophysical communities will benefit almost all branches of astrophysics.Comment: Submitted to the Astro2020 Decadal Survey White Paper cal

No Massive Companion to the Coherent Radio-Emitting M Dwarf GJ 1151

The recent detection of circularly polarized, long-duration (>8 hr) low-frequency (~150 MHz) radio emission from the M4.5 dwarf GJ 1151 has been interpreted as arising from a star-planet interaction via the electron cyclotron maser instability. The existence or parameters of the proposed planets have not been determined. Using 20 new HARPS-N observations, we put 99th-percentile upper limits on the mass of any close companion to GJ 1151 at Msini < 5.6 M earth. With no stellar, brown dwarf, or giant planet companion likely in a close orbit, our data are consistent with detected radio emission emerging from a magnetic interaction between a short-period terrestrial-mass planet and GJ 1151