Time comparison via OTS-2

The time comparisons carried out via OTS-2 between the Technical University Graz (Austria) and the Van Swinden Laboratory Delft (Netherlands) are discussed. The method is based on the use of the synchronization pulse in the TV-frame of the daily evening broadcasting of a French TV-program to Northern Africa. Corrections, as a consequence of changes in the position of the satellite coordinates are applied weekly after reception of satellite coordinates. A description of the method is given as well as some of the particular techniques used in both the participating laboratories. Preliminary results are presented

Paternalism to Partnership: The Administration of Indian Affairs, 1786–2021

Paternalism to Partnership examines the administration of Indian affairs from 1786, when the first federal administrator was appointed, through 2021. David H. DeJong examines each administrator through a biographical sketch and excerpts of policy statements defining the administrator’s political philosophy, drawn from official reports or the administrator’s own writings. The Indian Office, as an executive agency under the secretary of war (1789 to 1849) and secretary of the interior (1849 to present), was directed by the president of the United States. The superintendents, chief clerks, commissioners, and assistant secretaries for Indian affairs administered policy as prescribed by Congress and the president. Each was also given a level of discretion in administering this policy. For most of the federal-Indian relationship, administrators were limited in influencing policy. This paternalism continued well into the twentieth century. Beginning in the 1960s Congress and the president ameliorated their views on the federal-Indian relationship and moved away from paternalism. Since 1966 every administrator of the Bureau of Indian Affairs has been Native American, and each has exercised increasing authority in shaping policy. This has given rise to a federal-Indian partnership that has witnessed tribal nations again exercising their inherent rights of self-government. In this documentary history David H. DeJong follows the progression of federal Indian policy over more than two hundred years, providing firsthand accounts of how the federal-Indian relationship has changed over the centuries

Paternalism to Partnership

A biographical sketch of each head of Indian affairs between 1786 and 2021, including each commissioner’s political philosophy

A spiral-like disk of ionized gas in IC 1459: Signature of a merging collision

The authors report the discovery of a large (15 kpc diameter) H alpha + (NII) emission-line disk in the elliptical galaxy IC 1459, showing weak spiral structure. The line flux peaks strongly at the nucleus and is more concentrated than the stellar continuum. The major axis of the disk of ionized gas coincides with that of the stellar body of the galaxy. The mass of the ionized gas is estimated to be approx. 1 times 10 (exp 5) solar mass, less than 1 percent of the total mass of gas present in IC 1459. The total gas mass of 4 times 10(exp 7) solar mass has been estimated from the dust mass derived from a broad-band color index image and the Infrared Astronomy Satellite (IRAS) data. The authors speculate that the presence of dust and gas in IC 1459 is a signature of a merger event

Paternalism to Partnership

A biographical sketch of each head of Indian affairs between 1786 and 2021, including each commissioner’s political philosophy

Structural health monitoring of a masonry viaduct with Fibre Bragg Grating sensors

The Marsh Lane viaduct is a masonry railway bridge constructed during the 19th century nearby Leeds Central Railway Station. The bridge appears significantly damaged due to the increase of the operational train loads over the last decades and due to environmental effects. Due to this degradation, extensive repair was conducted in 2015. After this repair work, an extensive fibre optic sensor network was installed below three spans of the bridge to monitor surface strains at 68 locations on the underside of the arch spans. The paper compares data collected from two monitoring periods, 16 months apart. Combining statistical analysis and signal processing techniques, the results show that local damage, as well as change in the global dynamic behaviour of the structure over time, can be effectively detected with the use of Fibre Bragg Grating sensors.This work is being funded by the Lloyd’s Register Foundation, EPSRC and Innovate UK through the Data-Centric Engineering programme of the Alan Turing Institute and through the Cambridge Centre for Smart Infrastructure and Construction (CSIC). Funding for the monitoring installation was provided by EPSRC under the Ref. EP/N021614/1 grant and by Innovate UK under the Ref. 920035 grant

A multi-sensing monitoring system to study deterioration of a railway bridge

This study presents a multi-sensing monitoring system recently installed in a Victorian railway viaduct in Leeds, UK. The viaduct is in continuous use since its construction during the 19th century and suffers extensive cracking due to the combined action of increased train loads and environmental effects. The bridge was retrofitted in 2015 and there was the need to assess the effectiveness of the intervention and better understand the ongoing deterioration process. For this reason, a multi-sensing system was designed that comprises a fibre Bragg grating network to measure distributed dynamic deformation across three arch spans of the bridge, acoustic emission sensors to detect rates of cracking, and high sensitivity accelerometers to study the dynamic response at critical locations. The system is self-sustaining, self-powered and remotely controlled, and uses an algorithm that combines information from the three different types of sensors to track variations of response parameters of the bridge over time.This work is being funded by the Lloyd’s Register Foundation, EPSRC and Innovate UK through the Data-Centric Engineering programme of the Alan Turing Institute and through the Cambridge Centre for Smart Infrastructure and Construction. Funding for the monitoring installation was provided by EPSRC under the Ref. EP/N021614/1 grant and by Innovate UK under the Ref. 920035 grant

The Marsh Lane Railway Viaduct: 2 Years of Monitoring with Combined Sensing and Surveying Technologies

Marsh Lane viaduct is a typical example of a 19th century brick masonry railway arch in the UK. It frequently carries passenger trains to and from Leeds Station. This paper broadly discusses the sensing techniques and associated analysis procedures used to (i) identify the reasons for existing damage, (ii) quantify their impact on the dynamic response of the structure and (iii) measure degradation of the response over a period of one year. To identify existing damage, distortions in geometry of the structure are examined with new point cloud processing techniques. With the aid of limit analyses, these distortions are interpreted, and past support movements which may have caused the distortions are identified. Then, to measure the dynamic response of the bridge, quasi-distributed fibre optic strain sensing and digital image correlation displacement measurement techniques are used. These highlight the increased dynamic response around locations of existing damage, and point out to the global mechanisms of response that could propagate damage. Continuous fibre optic strain measurements between November 2017 and 2018 are then discussed to investigate the ongoing deterioration.This work is being funded by the Lloyd’s Register Foundation, EPSRC and Innovate UK through the Data-Centric Engineering programme of the Alan Turing Institute and through the Cambridge Centre for Smart Infrastructure and Construction. Funding for the monitoring installation was provided by EPSRC under the Ref. EP/N021614/1 grant and by Innovate UK under the Ref. 920035 grant

The Evolutionary Dynamics of Digital and Nucleotide Codes: A Mutation Protection Perspective

Both digital codes in computers and nucleotide codes in cells are protected against mutations. Here we explore how mutation protection affects the random change and selection of digital and nucleotide codes. We illustrate our findings with a computer simulation of the evolution of a population of self replicating digital amoebae. We show that evolutionary programming of digital codes is a valid model for the evolution of nucleotide codes by random change within the boundaries of mutation protection, not for evolution by unbounded random change. Our mutation protection perspective enhances the understanding of the evolutionary dynamics of digital and nucleotide codes and its limitations, and reveals a paradox between the necessity of dysfunctioning mutation protection for evolution and its disadvantage for survival. Our mutation protection perspective suggests new directions for research into mutational robustness