N-(4,6-Dimethyl­pyrimidin-2-yl)-1,3-benzothia­zol-2-amine

In the title compound, C13H12N4S, an amino N atom is connected to a 1,3-benzothia­zole fused-ring system and a dimethyl-substituted pyrimidine ring, these components being aligned [inter­planar dihedral angle = 1.9 (1)°]. The secondary amino N atom forms an inter­molecular N—H⋯N hydrogen bond to an N atom of the fused ring of an adjacent mol­ecule, generating a centrosymmetric cyclic hydrogen-bonded dimer [graph set R 2 2(8)]

Seismic behavior of semi-rigid steel frames

The widespread and unexpected damage to welded connections during recent earthquakes led to the investigation of alternatives for the construction of steel frames in seismic areas. Bolted semi-rigid connections have been recognized as an attractive alternative to welded connections. However, existing knowledge on the behavior of the connection is either from testing of beam-to-column subassemblies under idealized load and boundary conditions, or from analytical studies. In addition, the system-level experimental behavior of semi-rigidly connected frames using real earthquake motions to conclusively verify the full potential of semi-rigidity (implying also partial-strength) in earthquake resistance application is lacking. To this end, an advanced hybrid simulation approach for the seismic assessment of steel frames with semi-rigid connections was proposed and successfully completed. Furthermore, nonlinear dynamic response-history analyses of semi-rigid frames with varying design parameters were conducted to evaluate the system performance under seismic events. The results of the hybrid simulation and the parametric studies are used to quantify various fundamental code parameters needed for the seismic design of structures. The hybrid simulation included the most reliable, realistic, and computationally efficient experimental and analytical modules, which were developed and successfully integrated in a closed-loop system-level simulation. Three hybrid simulations were conducted on three different partial-strength semi-rigid frames with connection capacities that are a percentage of the plastic moment capacity of the beam (70% Mpbeam, 50% Mpbeam, and 30% Mpbeam). The simulations utilized the large-scale Multi-Axial Full-Scale Sub-Structured Testing and Simulation (MUST-SIM) facility at the University of Illinois and included a full-scale physical specimen for the experimental module and a 2D finite element model for the analytical module. The experimental component consisted of a beam-column subassembly with top-and seat-angle with double web-angle connecting the beam to the column. The analytical component is an inelastic finite element model with the connections modeled using a refined 2D continuum elements that is capable of capturing all relevant deformation and inelastic features of the connection. In addition to the hybrid simulation, nonlinear dynamic response-history analyses were conducted, on frames with three different connection capacities (70% Mpbeam, 50% Mpbeam, and 30% Mpbeam), using a collection of ground motion records scaled to the maximum considered earthquake (MCE). The analyses were aimed at investigating the effect of varying different design parameters on the seismic response and period elongation of the frames. The design parameters, in addition to connection strength, included yield strength of the angle material, coefficient of friction between faying surfaces, and the amount of slip allowed in the connection. The results of the hybrid simulation along with the analytical studies were used to evaluate more realistic fundamental code parameters needed for the seismic design of frames. The parameters included the equivalent damping ratio, ???eq, the inelastic period of the structure, Tinealstic, and a demand-based force reduction factor, Rdemand. The evaluated parameters can be used to better estimate the design base shear using a simplified design spectrum, allowing for safer and economical design of semi-rigid frames under seismic events

Impact of multiple waves of COVID-19 on healthcare networks in the United States.

The risk of overwhelming hospitals from multiple waves of COVID-19 is yet to be quantified. Here, we investigate the impact of different scenarios of releasing strong measures implemented around the U.S. on COVID-19 hospitalized cases and the risk of overwhelming the hospitals while considering resources at the county level. We show that multiple waves might cause an unprecedented impact on the hospitals if an increasing number of the population becomes susceptible and/or if the various protective measures are discontinued. Furthermore, we explore the ability of different mitigation strategies in providing considerable relief to hospitals. The results can help planners, policymakers, and state officials decide on additional resources required and when to return to normalcy

Real-time Application of the Multihazard Hurricane Impact Level Model for the Atlantic Basin

Tropical cyclones are an example of a multihazard event with impacts that can highly vary depending on landfall location, wind speed, storm surge, and inland flooding from precipitation. These storms are typically categorized by their wind speed and pressure, while evacuation orders are typically given based on storm surge. The general public relies on these single hazard assessment parameters when attempting to understand the risk of an oncoming event. However, after the fact, these events are ranked by economic damage and death toll. Therefore, it is imperative that when these events are communicated to the public, during the forecast period, the multiple hazards are incorporated in terms the public can easily associate with, such as economic damage. This article provides an evaluation of the potential for real-time use of artificial neural networks, through the utilization of an already developed Hurricane Impact Level (HIL) Model, to forecast a range of economic damage from tropical cyclone events, during the 2015 and 2016 United States hurricane season. The HIL Model is built prior to the start of each season and simulated every 3 h, in conjunction with National Hurricane Center (NHC) issued advisories, for oncoming tropical cyclones forecasted to make landfall. Weaker and more common tropical cyclones have a less varied forecast and produce more accurate impact level (IL) predictions. More complicated and uncertain events, such as 2016 Hurricane Matthew, require the user’s discretion in communicating varying landfall locations for a complex track forecast to the model. As NHC forecasts change with respect to both track and meteorological hazards affecting land, the estimated IL and the HIL model confidence will also change. In other words, if a track shifts to a more vulnerable location, or to more locations, or the meteorological hazards increase, the IL will subsequently increase. All tropical cyclones from the 2015 and 2016 seasons demonstrate the validity of the HIL Model with a forecast confidence of at least 60% for up to 30 h out from an impending landfall

Resilience of School Systems Following Severe Earthquakes

Abstract Natural disasters may have catastrophic and long‐lasting impacts on communities' physical, economic, and social infrastructure. Slow recovery of educational services following such events is likely to cause traumatic stress in children, lead families to out‐migrate, and affect the community's overall social stability. Methods for quantifying and assessing the restoration process of educational systems and their dependencies on other supporting infrastructure have not received adequate attention. This study introduces, for the first time, a new framework to evaluate the functionality, recovery, and resilience of a school system following severe earthquake events. The framework considers both the quantity and quality of education services provided, school enrollment, and staff employment, as well as the interaction between various agents such as staff, students, parents, administration, and community. A virtual testbed community, Centerville, is utilized to highlight the application of this framework. The impact of school reopening policies on the number of students enrolled as well as the potential for homeschooling is also considered. The availability of various enrollment alternatives for students, backup classroom space and functioning utility systems, and facilitation of staff and supplies transfer between schools substantially increase the resilience of the education service

Shaping urbanization to achieve communities resilient to floods

Flood risk is increasing in urban communities due to climate change and socioeconomic development. Socioeconomic development is a major cause of urban expansion in flood-prone regions, as it places more physical, economic, and social infrastructure at risk. Moreover, in light of the 2030 Agenda for Sustainable Development by the United Nations, it has become an international imperative to move toward sustainable cities. Current approaches to quantify this risk use scenario-based methods involving arbitrary projections of city growth. These methods seldom incorporate geographical, social, and economic factors associated with urbanization and cannot mimic city growth under various urban development plans. In this paper, we introduce a framework for understanding the interactions between urbanization and flood risk as an essential ingredient for flood risk management. This framework integrates an urban growth model with a hazard model to explore flood risk under various urban development scenarios. We then investigate the effectiveness of coupling nonstructural flood mitigation measures—in terms of urban planning policies and socioeconomic incentives—with urban growth processes to achieve sustainable and resilient communities. Using this framework, we can not only simulate urban expansion dynamics through time and its effect on flood risk but also model the growth of a region under various urban planning policies and assess the effectiveness of these measures in reducing flood risk. Our analysis reveals that while current urban development plans may put more people and assets at flood risk, the nonstructural strategies considered in this study mitigated the consequences of floods. Such a framework could be used to assist city planners and stakeholders in examining tradeoffs between costs and benefits of future land development in achieving sustainable and resilient cities