Letter from J. W. Lindt to John Muir, 1908 Jul 24.

[1]24 july 1908To John Muir [Esq?]for favor ofMrs Taylor04248[2]24 July 1908To John Muir EsqArizona, CaliforniaTo show that I have not forgotten you I send this card with kind remembrances & best wishes.[J.W.?] LindtFor favor of Mrs Taylor.0424

Strain adjustments associated with earthquakes in southern California

A technique for the calculation of strain changes in a two-dimensional elastic body with arbitrary internal dislocations is presented. This technique is applied to the southern California region by assigning a specific fault and fault slip function for each major earthquake that has occurred since 1812. Although the model used has serious shortcomings when applied to the real Earth, certain important features concerning strain energy changes associated with earthquakes are brought out. The occurrence of earthquakes over the past 150 years has resulted in net increases in stored strain energy in a number of regions including the northern end of the Gulf of California, the Cajon Pass area, and the northern part of the Carizzo Plain. Large regions of strain energy decrease can also be seen, the most important of which is in the vicinity of Fort Tejon

Minimum Performance Targets for the Built Environment based on Community-Resilience Objectives

Disrupted critical infrastructure systems following disasters can result in population outmigration which may subsequently negatively impact a communitys indirect socioeconomic losses over time. In this study, a community was modeled with its interconnected physical-socio-economic attributes and population outmigration was used as a basic proxy community resilience metric. The probability of outmigration for each household was assessed based on the probability that the school-age students, household residents, and employees in the household are affected over a prescribed time period from the occurrence of the hazard to the full restoration of the community. Finally, the potential population outmigration for the community was assessed by aggregating the probability for all the households in the community. Additionally, a prediction model for the number of injuries and fatalities was implemented in the analysis to be served as a community-level life-safety metric. Ultimately, these metrics were combined and utilized to propose a framework for disaggregation of a set of community-level objectives into a set of performance targets for the components of the built environment. Such a model is desirable for policymakers and community leaders in order to make long-term decisions for their community

Seismic Performance Comparison of a High-Content SDA Frame and Standard RC Frame

This study presents the method and results of an experiment to study the seismic behavior of a concrete portal frame with fifty percent of its cement content replaced with a spray dryer ash (SDA). Based on multiple-shake-table tests, the high content SDA frame was found to perform as well as the standard concrete frame for two earthquakes exceeding design-level intensity earthquakes. Hence, from a purely seismic/structural standpoint, it may be possible to replace approximately fifty percent of cement in a concrete mix with SDA for the construction of structural members in high seismic zones. This would help significantly redirect spray dryer ash away from landfills, thus, providing a sustainable greener alternative to concrete that uses only Portland cement, or only a small percentage of SDA or fly ash

Development of empirically-based fragilities of residential damage in the 2011 Joplin, Missouri tornado

Performance-based engineering (PBE) is a methodology that requires specification on a range of performances or target reliabilities for structures of different importance. Information on these ‘performance levels’ require a probabilistic assessment of the potential factors that may influence a design, including information on the hazard, load, resistance, loss estimates, expert opinion and public perception. This paper describes one such probabilistic assessment in the development of empirically-based fragility functions for tornadoes using damage assessment data and a tornado wind field model for the 22 May 2011 Joplin, MO tornado. The damage assessment data was collected during field surveys of more than 1,240 structures in the aftermath of the tornado, using provisions of the Enhanced Fujita (EF) Scale to assess the damage. The wind field model was developed from the tree-fall patterns noted in the damage path of the tornado. Fragility functions were developed for the Degrees of Damage (DOD) associated with One- and Two-Family Residences in the EF Scale. The empiricallyderived fragility functions were progressive in nature, with median wind speeds varying from 33.6 m/s for initiation of visible damage to 85.2 m/s for complete destruction. These functions were compared to existing fragility functions for straightline winds to evaluate potential differences in failure mechanisms for structures exposed to tornadoes. Wind speeds associated with the median failure probability were used to estimate load factors, defined as the square of the ratio of the straightline wind speed to the tornado wind speed. Structures tended to fail at lower wind speeds in tornadoes than in straightline winds, with load factors between 1.32 and 1.51. A fragility assessment in the context of PBE naturally requires attribution and quantification of all uncertainties. Uncertainties in the both the damage and wind speed estimation in the development of fragilities are quantified and assessed using Monte Carlo methods. Preliminary results show variance in fragility parameters is higher for higher damage states but all damage states have relatively low coefficients of variation

Computational environment for modeling and enhancing community resilience: Introducing the center for risk-based community resilience planning

The resilience of a community is defined as its ability to prepare for, withstand, recover from and adapt to the effects of natural or human-caused disasters, and depends on the performance of the built environment and on supporting social, economic and public institutions that are essential for immediate response and long-term recovery and adaptation. The performance of the built environment generally is governed by codes, standards, and regulations, which are applicable to individual facilities and residences, are based on different performance criteria, and do not account for the interdependence of buildings, transportation, utilities and other infrastructure sectors. The National Institute of Standards and Technology recently awarded a new Center of Excellence (NIST-CoE) for Risk-Based Community Resilience Planning, which is headquartered at Colorado State University and involves nine additional universities. Research in this Center is focusing on three major research thrusts: (1) developing the NIST-Community Resilience Modeling Environment known as NIST-CORE, thereby enabling alternative strategies to enhance community resilience to be measured quantitatively; (2) developing a standardized data ontology, robust data architecture and data management tools in support of NIST-CORE; and (3) performing a comprehensive set of hindcasts on disasters to validate the data architecture and NIST-CORE

Thermal magnetic resonance: physics considerations and electromagnetic field simulations up to 23.5 Tesla (1GHz)

Background: Glioblastoma multiforme is the most common and most aggressive malign brain tumor. The 5-year survival rate after tumor resection and adjuvant chemoradiation is only 10 %, with almost all recurrences occurring in the initially treated site. Attempts to improve local control using a higher radiation dose were not successful so that alternative additive treatments are urgently needed. Given the strong rationale for hyperthermia as part of a multimodal treatment for patients with glioblastoma, non-invasive radio frequency (RF) hyperthermia might significantly improve treatment results. Methods: A non-invasive applicator was constructed utilizing the magnetic resonance (MR) spin excitation frequency for controlled RF hyperthermia and MR imaging in an integrated system, which we refer to as thermal MR. Applicator designs at RF frequencies 300 MHz, 500 MHz and 1GHz were investigated and examined for absolute applicable thermal dose and temperature hotspot size. Electromagnetic field (EMF) and temperature simulations were performed in human voxel models. RF heating experiments were conducted at 300 MHz and 500 MHz to characterize the applicator performance and validate the simulations. Results: The feasibility of thermal MR was demonstrated at 7.0 T. The temperature could be increased by ~11 °C in 3 min in the center of a head sized phantom. Modification of the RF phases allowed steering of a temperature hotspot to a deliberately selected location. RF heating was monitored using the integrated system for MR thermometry and high spatial resolution MRI. EMF and thermal simulations demonstrated that local RF hyperthermia using the integrated system is feasible to reach a maximum temperature in the center of the human brain of 46.8 °C after 3 min of RF heating while surface temperatures stayed below 41 °C. Using higher RF frequencies reduces the size of the temperature hotspot significantly. Conclusion: The opportunities and capabilities of thermal magnetic resonance for RF hyperthermia interventions of intracranial lesions are intriguing. Employing such systems as an alternative additive treatment for glioblastoma multiforme might be able to improve local control by "fighting fire with fire". Interventions are not limited to the human brain and might include temperature driven targeted drug and MR contrast agent delivery and help to understand temperature dependent bio- and physiological processes in-vivo

Concept of Community Fragilities for Tsunami Coastal Inundation Studies

Tsunamis have devastated coastal regions worldwide, with the most recent being the result of the Great Tohoku Japan earthquake and tsunami, which was a M9.0 undersea megathrust earthquake that occurred off the east coast of Japan on March 11, 2011. In this study, a fragility formulation is utilized to develop and illustrate the concept of community fragilities for a community subjected to a wave of a particular height because fragilities are independent of occurrence rate. The fragility formulation for single structures is explained and then extended to the community scale by assigning one of eight archetype structural models and corresponding fragility to each of the buildings in a community. One key feature of the approach is that both the earthquake and tsunami are considered in succession. Three wave forces, i.e., hydrostatic, hydrodynamic, and impulsive wave forces, and the successive hazard loadings, i.e., earthquakes and tsunamis, were considered during the analysis. While debris loading is often critical during inundation, it is not assessed here but should be eventually considered. The tsunami fragility methodology is briefly demonstrated on a single building and then extended to Cannon Beach, Oregon, as an illustrative example. The fragility approach shows that community fragilities follow a similar trend with single structure fragilities and can help with decision making for retrofit and land-use planning. The concept proposed herein can provide a framework regardless of the structural or hydrodynamic model used, provided information on the community is available and a basic understanding of the structure types can be developed

Tsunami bore forces on a compliant residential building model

The forces exerted on light-frame wood buildings as a result of surge and waves are not fully understood. With a better understanding of these types of forces, it may eventually be possible to build coastal structures to better withstand the loads. In this paper, a recent two part experimental study that focused on determining the forces induced in a structurally compliant model of a typical Gulf Coast residential building is summarized. The one-sixth scale building was designed to approximately behave as the full scale building would under wave loading using rules of energy-based similitude. The compliant model was subjected to solitary wave loading in the Network for Earthquake Engineering Simulation (NEES) tsunami wave basin (TWB) at Oregon State University with wave heights ranging from 0.1 m to 0.6 m. Then, at Colorado State University, lateral force–deformation tests on a nominally identical model were performed in order to determine the force–deformation relationship for the building. The structural deformation produced by solitary waves in the wave basin was combined with the experimentally measured deformation in the structural laboratory to determine the force induced by the waves between 0.2m and 0.6 m. Finally, a simplified force equation constant similar to the existing design code formats was found to be 0.31

Multi-hazard socio-physical resilience assessment of hurricane-induced hazards on coastal communities

Hurricane-induced hazards can result in significant damage to the built environment cascading into major impacts to the households, social institutions, and local economy. Although quantifying physical impacts of hurricane-induced hazards is essential for risk analysis, it is necessary but not sufficient for community resilience planning. While there have been several studies on hurricane risk and recovery assessment at the building- and community-level, few studies have focused on the nexus of coupled physical and social disruptions, particularly when characterizing recovery in the face of coastal multi-hazards. Therefore, this study presents an integrated approach to quantify the socio-physical disruption following hurricane-induced multi-hazards (e.g., wind, storm surge, wave) by considering the physical damage and functionality of the built environment along with the population dynamics over time. Specifically, high-resolution fragility models of buildings, and power and transportation infrastructures capture the combined impacts of hurricane loading on the built environment. Beyond simulating recovery by tracking infrastructure network performance metrics, such as access to essential facilities, this coupled socio-physical approach affords projection of post-hazard population dislocation and temporal evolution of housing and household recovery constrained by the building and infrastructure recovery. The results reveal the relative importance of multi-hazard consideration in the damage and recovery assessment of communities, along with the role of interdependent socio-physical system modeling when evaluating metrics such as housing recovery or the need for emergency shelter. Furthermore, the methodology presented here provides a foundation for resilience-informed decisions for coastal communities