Managing the Internet Payment Platform project

This case examines issues in the assessment and adoption of Internet technologies in a federal US government context, and describes in detail a pilot project to determine the feasibility of adopting an application service provider solution to support procurement by multiple federal agencies using a variety of different legacy transaction systems. The pilot test of the Internet Payment Platform (IPP) by the eMoney group of the United States Treasury\u27s Financial Management Service involved three federal agencies and subsets of their suppliers. Participants saw many benefits from their use of the IPP, but agreed that for full-scale operation it needed to be modified to better fit the government procurement context. The project manager is weighing the pros and cons of conducting another pilot test using the same commercial software as before, or obtaining and customizing a new commercial package, or building a new system from scratch

The U.S. Treasury Tests a New Payment Mechanism

This case presents a set of technical issues confronting the United States Treasury eCheck Pilot Project team in January 2000. The team, which included representatives from the U.S. Treasury, the Federal Reserve Bank of Boston, Fleet Boston, Bank of America, and several hardware and software vendors, was testing a new Internet-based payment mechanism (eCheck). The system had already been tested for a year and a half with the participation of the two commercial banks (Fleet Boston, Bank of America), but this portion of the pilot was now coming to an end. During the first phase of the project, several key design choices had been made, including the use of smart cards to hold digital certificates, and specification of the information flows among the participants (payer, payee, payer bank, payee bank). Now, the system would need to be modified so that the U.S. Treasury could continue to make eCheck payments to a few defense contractors, with the help of the Federal Reserve Bank of Boston. Two new designs are presented for evaluation

Defining the Efficacy of Aortic Root Enlargement Procedures: A Comparative Analysis of Surgical Techniques

Background: Aortic root enlargement (ARE) procedures are believed to allow implantation of larger valve prostheses; however, little evidence exists to support the specific efficacy of various techniques. Methods: Using a cadaveric model, 20 adult (72.4 +/- 15.3 years) hearts were stratified into 4 groups based on annular diameter: \u3c20 mm, 20-22 mm, 22-24 mm, and \u3e24 mm. Each heart underwent an aortic valve replacement following a Nicks, Manougian, aortoventriculoplasty and modified Bentall procedure, with appropriate reversals between procedures. Results: All 4 groups experienced similar increases in annular diameter (P = 0.43) and prosthesis size implanted (P = 0.51) with each enlargement technique. The Nicks, Manougian, modified Bentall and aortoventriculoplasty procedures enlarged the annulus by 0.43 +/- 0.45 mm, 3.63 +/- 0.95 mm, 0.78 +/- 0.65 mm, and 6.08 +/- 1.19 mm, respectively (P \u3c 0.001). No significant change in prosthesis size was observed after the Nicks procedure (P = not significant). Increases of 1.3 +/- 0.5, 1.3 +/- 0.5, and 2.7 +/- 0.6 prosthesis sizes were achieved with the Manougian, modified Bentall and aortoventriculoplasty techniques respectively (P \u3c 0.001). Conclusions: ARE procedures appear equally efficacious in both small and larger aortic roots. Although all 4 ARE techniques increased the annular diameter, only the Manougian, modified Bentall and aortoventriculoplasty procedures allowed for the implantation of a larger prosthetic valve. The Nicks procedure, which is likely the most commonly performed ARE, does not allow for the implantation of a larger prosthesis. Surgeon preference and patient factors may help in selecting the most appropriate ARE technique, as the modified Bentall and Manougian procedures achieved similar increases in valve size

A Boreing Night of Observations of the Upper Mesosphere and Lower Thermosphere Over the Andes Lidar Observatory

A very high-spatial resolution (∼21-23 m pixel at 85 km altitude) OH airglow imager at the Andes Lidar Observatory at Cerro Pach´on, Chile observed considerable ducted wave activity on the night of October 29-30, 2016. This instrument was collocated with a Na wind-temperature lidar that provided data revealing the occurrence of strong ducts. A large field of view OH and greenline airglow imager showed waves present over a vertical extent consistent with the altitudes of the ducting features identified in the lidar profiles. While waves that appeared to be ducted were seen in all imagers throughout the observation interval, the wave train seen in the OH images at earlier times had a distinct leading non-sinusoidal phase followed by several, lower-amplitude, more sinusoidal phases, suggesting a likely bore. The leading phase exhibited significant dissipation via small-scale secondary instabilities suggesting vortex rings that progressed rapidly to smaller scales and turbulence (the latter not fully resolved) thereafter. The motions of these small-scale features were consistent with their location in the duct at or below ∼83-84 km. Bore dissipation caused a momentum flux divergence and a local acceleration of the mean flow within the duct along the direction of the initial bore propagation. A number of these features are consistent with mesospheric bores observed or modeled in previous studies

Kelvin-Helmholtz Billow Interactions and Instabilities In The Mesosphere Over the Andes Lidar Observatory: 1. Observations

A very high spatial resolution (∼25 m pixel at 90 km altitude) OH airglow imager was installed at the Andes Lidar Observatory on Cerro Pachón, Chile, in February 2016. This instrument was collocated with a Na wind-temperature lidar. On 1 March 2016, the lidar data showed that the atmosphere was dynamically unstable before 0100 UT and thus conducive to the formation of Kelvin-Helmholtz instabilities (KHIs). The imager revealed the presence of a KHI and an apparent atmospheric gravity wave (AGW) propagating approximately perpendicular to the plane of primary KHI motions. The AGW appears to have induced modulations of the shear layer leading to misalignments of the emerging KHI billows. These enabled strong KHI billow interactions, as they achieved large amplitudes and a rapid transition to turbulence thereafter. The interactions manifested themselves as vortex tube and knot features that were earlier identified in laboratory studies, as discussed in Thorpe (1987, https://doi.org/10.1029/ JC092iC05p05231; 2002, https://doi.org/10.1002/qj.200212858307) and inferred to be widespread in the atmosphere based on features seen in tropospheric clouds but which have never been identified in previous upper atmospheric observations. This study presents the first high-resolution airglow imaging observation of these KHI interaction dynamics that drive rapid transitions to turbulence and suggest the potential importance of these dynamics in the mesosphere and at other altitudes. A companion paper (Fritts et al., 2020, https://doi.org/10.1029/2020JD033412) modeling these dynamics confirms that the vortex tubes and knots yield more rapid and significantly enhanced turbulence relative to the internal instabilities of individual KHI billows

Business Process Modeling for Successful Implementation of Interorganizational Systems

Studies show that the physical implementation of an interorganizational business process or system can be a major source of operational problems and reduced business benefits. Better process modeling has been advocated as a solution. Although powerful modeling tools exist, current practice often gives short-shrift to documenting the physical implementation details that can create or exacerbate such problems. In this paper we describe the modeling approach we devised for the interorganizational business processes and systems we observe in our ongoing fieldwork. Our approach involves using allowable extensions to a popular modeling notation (BPMN), although other modeling tools would work equally well. We illustrate the benefit of our approach in the case of the Internet Payment Platform, a pilot project of the United States Department of the Treasury

Simultaneous observations of the phase-locked 2 day wave at Adelaide, Cerro Pachon, and Darwin

The Southern Hemisphere summer 2 day wave (TDW) is the most dramatic large-scale event of the upper mesosphere. The winds accelerate over _1 week, may attain \u3e 70 m/s, and are often accompanied by a near disappearance of the diurnal tide and stabilization of the period close to 48 h. We denote this as the phase-locked 2 day wave (PL/TDW). We have examined airglow and meteor radar (MR) wind data from the Andes Lidar Observatory (Cerro Pachon, Chile:30¡S, 289.3¡E), MR data from Darwin (12.5¡S, 131¡E) and airglow and medium frequency radar data from the University of Adelaide (34.7¡S, 138.6¡E) for the behavior of the TDW during the austral summers of 2010, 2012, and 2013. The Cerro Pachon and Adelaide sites are located at similar latitudes separated in longitude by about 120¡. We find a remarkable coincidence between the TDW oscillations at Chile and Adelaide for the period January-February 2010. The oscillations are nearly in phase in terms of local time and the minima and maxima repeat at nearly the same local time from cycle to cycle consistent with a phase-locked wave number 3 TDW. Data for this and other years (including Darwin) show that the amplitude of the diurnal tide decreases when the TDW is largest and that this occurs when the period is close to 48 h. These observations support the proposal that the PL/TDW is a subharmonic parametric instability wherein the diurnal tide transfers energy to a TDW that is resonant at nearly 48 h. ©2015. American Geophysical Union. All Rights Reserved

Identification of a triplet pair intermediate in singlet exciton fission in solution.

Singlet exciton fission is the spin-conserving transformation of one spin-singlet exciton into two spin-triplet excitons. This exciton multiplication mechanism offers an attractive route to solar cells that circumvent the single-junction Shockley-Queisser limit. Most theoretical descriptions of singlet fission invoke an intermediate state of a pair of spin-triplet excitons coupled into an overall spin-singlet configuration, but such a state has never been optically observed. In solution, we show that the dynamics of fission are diffusion limited and enable the isolation of an intermediate species. In concentrated solutions of bis(triisopropylsilylethynyl)[TIPS]--tetracene we find rapid (<100 ps) formation of excimers and a slower (∼ 10 ns) break up of the excimer to two triplet exciton-bearing free molecules. These excimers are spectroscopically distinct from singlet and triplet excitons, yet possess both singlet and triplet characteristics, enabling identification as a triplet pair state. We find that this triplet pair state is significantly stabilized relative to free triplet excitons, and that it plays a critical role in the efficient endothermic singlet fission process.H.L.S was supported by the Winton Programme for the Physics of Sustainability and A.J.M received funding from the Engineering and Physical Sciences Research Council.This is the accepted manuscript. The final version is available at http://www.pnas.org/content/112/25/7656.abstract

Development of Level 1b Calibration and Validation Readiness, Implementation and Management Plans for GOES-R

A complement of Readiness, Implementation and Management Plans (RIMPs) to facilitate management of post-launch product test activities for the official Geostationary Operational Environmental Satellite (GOES-R) Level 1b (L1b) products have been developed and documented. Separate plans have been created for each of the GOES-R sensors including: the Advanced Baseline Imager (ABI), the Extreme ultraviolet and X-ray Irradiance Sensors (EXIS), Geostationary Lightning Mapper (GLM), GOES-R Magnetometer (MAG), the Space Environment In-Situ Suite (SEISS), and the Solar Ultraviolet Imager (SUVI). The GOES-R program has implemented these RIMPs in order to address the full scope of CalVal activities required for a successful demonstration of GOES-R L1b data product quality throughout the three validation stages: Beta, Provisional and Full Validation. For each product maturity level, the RIMPs include specific performance criteria and required artifacts that provide evidence a given validation stage has been reached, the timing when each stage will be complete, a description of every applicable Post-Launch Product Test (PLPT), roles and responsibilities of personnel, upstream dependencies, and analysis methods and tools to be employed during validation. Instrument level Post-Launch Tests (PLTs) are also referenced and apply primarily to functional check-out of the instruments