Soft X-ray Photochemistry at the L₂,₃-edges in K₃[Fe(CN)₆], [Co(acac)₃] and [Cp₂Fe][BF₄]

Soft X-ray photoreduction has been observed in K3[Fe(CN)6], [Co(acac)3] and [Cp2Fe][BF4]

Concert recording 2022-04-02a

[Track 1]. Boris Kerner / Caroline Shaw (arr. Dylan Matheny) -- [Track 2]. Limestone & felt / Caroline Shaw (arr. Dylan Matheny) -- [Track 3]. Snapshots. I. Frantic, hyperventilating ; II. Chain ; III. Nervous ; IV. Early bird special / Takuma Itah -- [Track 4]. Different trains. III. After the war / Steve Reich (arr. Dylan Matheny) -- [Track 5]. Stubborn as hell / Stacy Garrop -- [Track 6]. Twitter birds blog / Takashi Yoshimatsu (arr. Dylan Matheny)

Concert recording 2022-04-02a

[Track 1]. Boris Kerner / Caroline Shaw (arr. Dylan Matheny) -- [Track 2]. Limestone & felt / Caroline Shaw (arr. Dylan Matheny) -- [Track 3]. Snapshots. I. Frantic, hyperventilating ; II. Chain ; III. Nervous ; IV. Early bird special / Takuma Itah -- [Track 4]. Different trains. III. After the war / Steve Reich (arr. Dylan Matheny) -- [Track 5]. Stubborn as hell / Stacy Garrop -- [Track 6]. Twitter birds blog / Takashi Yoshimatsu (arr. Dylan Matheny)

Interview with Mary Catherine Roper

For transcript, click the Download button above. For video index, click the link below. Mary Catherine Roper (L \u2793) is the deputy legal director at the ACLU of Pennsylvania, where she coordinates litigation on a broad range of civil liberties issues, including freedom of speech, religious liberty, racial and ethnic justice, equality for lesbians and gay men, student rights, privacy, prisoners’ rights, and police misconduct. Prior to joining the ACLU, Mary Catherine was a partner in the firm of Drinker Biddle and Reath, where she was well known for her commitment to pro bono work. After law school, she clerked for the Honorable Anita B. Brody of the United States District Court for the Eastern District of Pennsylvania and served a year with the Disabilities Law Project as the first recipient of the Philadelphia Bar Foundation Public Interest Fellowship

Terrain-aided navigation for long-range AUVs in dynamic under-mapped environments

Deploying long‐range autonomous underwater vehicles (AUVs) mid‐water column in the deep ocean is one of the most challenging applications for these submersibles. Without external support and speed over the ground measurements, dead‐reckoning (DR) navigation inevitably experiences an error proportional to the mission range and the speed of the water currents. In response to this problem, a computationally feasible and low‐power terrain‐aided navigation (TAN) system is developed. A Rao‐Blackwellized Particle Filter robust to estimation divergence is designed to estimate the vehicle's position and the speed of water currents. To evaluate performance, field data from multiday AUV deployments in the Southern Ocean are used. These form a unique test case for assessing the TAN performance under extremely challenging conditions. Despite the use of a small number of low‐power sensors and a Doppler velocity log to enable TAN, the algorithm limits the localisation error to within a few hundreds of metres, as opposed to a DR error of 40 km, given a 50 m resolution bathymetric map. To evaluate further the effectiveness of the system under a varying map quality, grids of 100, 200, and 400 m resolution are generated by subsampling the original 50 m resolution map. Despite the high complexity of the navigation problem, the filter exhibits robust and relatively accurate behaviour. Given the current aim of the oceanographic community to develop maps of similar resolution, the results of this study suggest that TAN can enable AUV operations of the order of months using global bathymetric models

Concert recording 2022-04-05

[Track 1]. In Bach\u27s studio -- [Track 2]. South Africa -- [Track 3]. The grey convoy -- [Track 4]. Ode for Leo -- [Track 5]. A moody time

Concert recording 2022-04-05

[Track 1]. In Bach\u27s studio -- [Track 2]. South Africa -- [Track 3]. The grey convoy -- [Track 4]. Ode for Leo -- [Track 5]. A moody time

Terrain‐aided navigation for long‐endurance and deep‐rated autonomous underwater vehicles

Terrain‐aided navigation (TAN) is a localisation method which uses bathymetric measurements for bounding the growth in inertial navigation error. The minimisation of navigation errors is of particular importance for long‐endurance autonomous underwater vehicles (AUVs). This type of AUV requires simple and effective on‐board navigation solutions to undertake long‐range missions, operating for months rather than hours or days, without reliance on external support systems. Consequently, a suitable navigation solution has to fulfil two main requirements: (a) bounding the navigation error, and (b) conforming to energy constraints and conserving on‐board power. This study proposes a low‐complexity particle filter‐based TAN algorithm for Autosub Long Range, a long‐endurance deep‐rated AUV. This is a light and tractable filter that can be implemented on‐board in real time. The potential of the algorithm is investigated by evaluating its performance using field data from three deep (up to 3,700 m) and long‐range (up to 195 km in 77 hr) missions performed in the Southern Ocean during April 2017. The results obtained using TAN are compared to on‐board estimates, computed via dead reckoning, and ultrashort baseline (USBL) measurements, treated as baseline locations, sporadically recorded by a support ship. Results obtained through postprocessing demonstrate that TAN has the potential to prolong underwater missions to a range of hundreds of kilometres without the need for intermittent surfacing to obtain global positioning system fixes. During each of the missions, the system performed 20 Monte Carlo runs. Throughout each run, the algorithm maintained convergence and bounded error, with high estimation repeatability achieved between all runs, despite the limited suite of localisation sensors