192 research outputs found

    The Next Step--Beyond Disaster Resistance to Resilience

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    The Disaster Resistant University program was initiated by FEMA during the Clinton administration. It eventually lost funding, but has been continued by several institutions of higher learning (IHLs) because they found that the program provided a practical common sense approach to disaster planning and mitigation. Recently, the Community and Regional Resilience Institute (CARRI) has begun an initiative to help IHLs go beyond resistance to resilience. No matter how resistant an institution is, it will eventually have to respond to and recover from an unexpected crisis – a lone gunman, an epidemic, an athletic scandal, or a natural disaster that exceeds its resources. Sometimes, the IHL will be caught in the cascading impacts of a crisis that strikes its neighboring community. CARRI has developed a Community Resilience System (CRS) to help communities enhance their resilience. At FEMA’s request, CARRI is adapting its CRS to help IHLs to become more resilient. At its heart, the CRS (like the Disaster Resistant University program) is rooted in a Whole Community approach – looking at all of an IHL’s stakeholders. CARRI’s campus resilience system will extend the successful framework of the DRU program by: · Looking beyond continuity of operations toward rapid and complete recovery of the institution. · Considering a wider range of risks. · Developing deeper partnerships with its stakeholders so that, if necessary, they can be more rapidly mobilized to assist in recovery. The essence of resilience is being able to rapidly recover from adversity without lasting harm; that is the goal of the campus resilience system

    The Next Step--Beyond Disaster Resistance to Resilience

    Get PDF
    The Disaster Resistant University program was initiated by FEMA during the Clinton administration. It eventually lost funding, but has been continued by several institutions of higher learning (IHLs) because they found that the program provided a practical common sense approach to disaster planning and mitigation. Recently, the Community and Regional Resilience Institute (CARRI) has begun an initiative to help IHLs go beyond resistance to resilience. No matter how resistant an institution is, it will eventually have to respond to and recover from an unexpected crisis – a lone gunman, an epidemic, an athletic scandal, or a natural disaster that exceeds its resources. Sometimes, the IHL will be caught in the cascading impacts of a crisis that strikes its neighboring community. CARRI has developed a Community Resilience System (CRS) to help communities enhance their resilience. At FEMA’s request, CARRI is adapting its CRS to help IHLs to become more resilient. At its heart, the CRS (like the Disaster Resistant University program) is rooted in a Whole Community approach – looking at all of an IHL’s stakeholders. CARRI’s campus resilience system will extend the successful framework of the DRU program by: · Looking beyond continuity of operations toward rapid and complete recovery of the institution. · Considering a wider range of risks. · Developing deeper partnerships with its stakeholders so that, if necessary, they can be more rapidly mobilized to assist in recovery. The essence of resilience is being able to rapidly recover from adversity without lasting harm; that is the goal of the campus resilience system

    Applications of a “Whole Community” Framework for Enhancing Community or Campus Resilience

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    AbstractThe Community and Regional Resilience Institute (CARRI) has developed a unique approach to community resilience based on a “Whole Community” concept. It treats communities as a collection of systems, each with its own resilience. CARRI has applied its approach to two kinds of communities: civil communities, and institutions of higher education (IHEs). For both civil communities and IHEs, CARRI carried out a pilot program. For each participant, their leadership directed an assessment of the resilience of the component systems to the types of changes most relevant to that community. Each assessment provided suggestions for filling any gaps identified as part of the assessment. The pilot for the seven IHEs followed that for the seven civil communities and was able to take advantage of lessons learned from the first. These two pilot programs led to the following conclusions:‱CARRI's systems-based approach is both understandable and usable by both types of communities. In practice, it seemed to provide a natural way to look at a community.‱In general, IHEs were able to make better use of the approach than civil communities. This is due, in part, to the improvements made in the IHE pilot program based on the civil communities’ results. However, it also reflects the more hierarchical nature of IHEs, the tighter coupling of systems within an IHE and greater discretion in the use of resources in an IHE.‱College campuses can be crucial catalysts for enhancing the resilience of civil communities.‱Leadership is a key, perhaps the key, element in the success of a community resilience initiative

    Insights into Chemical Dynamics and Their Impact on the Reactivity of Pt Nanoparticles during CO Oxidation by Operando TEM

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    The functionality of heterogeneous catalysts is influenced by a delicate interplay of multiple parameters, including morphology and structure, chemical potential gradients and related dynamics. Here, we report on how these factors are interconnected. Combining time-resolved transmission electron microscopy imaging and selected area electron diffraction with online conversion detection, CO oxidation over Pt nanoparticles was studied at a pressure of 700 mbar and temperatures up to 500 °C. The different interactions between reactants and catalysts over the entire range of catalytic conversion were investigated. Chemical dynamics in this reaction were found to consist of both morphological transformations and fluctuating structural dynamics. Morphological transformations were observed mostly in low activity regimes, leading to nanoparticles with increased stable surface facets. Meanwhile structural changes were observed during high activity regimes where the partial pressures remained constant. Furthermore, the observed changes were found to occur in both the bulk and the surface of the catalyst. Catalytic cycling revealed that morphological transformations and structural dynamics have different implications on the reactivity and are mostly irreversible

    Mechanochemical stability of hydrogen titanate nanostructures

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    Structural stability of nanostructured titanates was investigated for further processing and possible applications. With the aim to investigate their mechanochemical stability we applied highenergy ball milling and studied induced phase transitions. Hydrogen titanates having two different morfologies, microcrystals and nanotubes, were taken into consideration. During mechanochemical treatment of both morphologies, we observed the phase transition from hydrogen titanate to TiO2 anatase and then to TiO2 rutile. Anatase to rutile phase transition occurred without appearance of intermediate high pressure TiO2 II typically observed in the case of mechanochemical treatment of TiO2. In the case of microcrystals, phase transition from hydrogen titanate to anatase starts after longer milling time than in the case of nanotubes, which is explained by larger particles sizes of crystalline powder. On the contrary, further phase transition from anatase to rutile was occurred faster in crystalline powder than in the case of nanotubes. The sequence of phase transitions was studied by Raman spectroscopy and X-ray powder diffraction, while morphology and crystal structure at nanoscale were analyzed by high resolution electron microscopy

    Site specific and localized structural displacements in open structured multimetallic oxides

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    The structures of solids can locally differ from the macroscopic picture obtained by structural averaging techniques. This difference significantly influences the performance of any functional material. Measurements of these local structures are challenging. Thus, the description of defects is often disregarded. However, in order to understand the functionality, such irregularities have to be investigated. Here, we present a high resolution scanning transmission electron microscopic (STEM) study revealing local structural irregularities in open structured oxides using catalytically active orthorhombic (Mo,V,Te,Nb)Ox as a complex example. Detailed analysis of annular dark field- and annular bright field-STEM images reveal site specific local structural displacements of individual framework and channel sites in the picometer range. These experimental observables can be considered as an important structural addendum for theoretical modelling and should be implemented into the existing data in order to quantify site specific potential energies and stresses. This information can further be used to describe the impact of the structure on the catalytic performance in greater detail

    SnBrP-A SnIP-type representative in the Sn-Br-P system

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    One-dimensional semiconductors are interesting materials due to their unique structural features and anisotropy, which grant them intriguing optical, dielectric and mechanical properties. In this work, we report on SnBrP, a lighter homologue of the first inorganic double helix compound SnIP. This class of compounds is characterized by intriguing mechanical and electronic properties, featuring a high flexibility without modulation of physical properties. Semiconducting SnBrP can be synthesized from red phosphorus, tin and tin(II)bromide at elevated temperatures and crystallizes as red-orange, cleavable needles. Raman measurements pointed towards a double helical building unit in SnBrP, showing similarities to the SnIP structure. After taking PL measurements, HR-TEM, and quantum chemical calculations into account, we were able to propose a sense full structure model for SnBrP

    Thermal behaviour of zircon/zirconia-added chemically durable borosilicate porous glass

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    Macroporous alkali resistant glass has been developed by making additions of zirconia (ZrO2) and zircon (ZrSiO4) to the sodium borosilicate glass system SiO2–B2O3 Na2O. The glass was made using a traditional high temperature fusion process. Differential thermal analysis (DTA) was carried out to identify the glass transition temperature (Tg) and crystallisation temperature (Tx). Based on these findings, controlled heat-treatments were implemented to separate the glass into two-phases; a silica-rich phase, and an alkali-rich borate phase. X-ray diffraction (XRD) was used to identify any crystal phases present in the asquenched and heat-treated glasses. Fourier transform infrared (FTIR) spectroscopy also proved effective in investigating phase separation and crystallisation behaviour. After leaching, a silica-rich skeleton with an interconnected pore structure and a uniform pore distribution was observed. Pore characterisation was carried out using mercury porosimetry. The size and shape of the pores largely depended on the heattreatment temperature and time. ZrO2/ZrSiO4 additions increased the alkali resistance of the porous glass 3–4 times

    In situ genesis of selective adsorption sites by complex catalytic redox dynamics

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    Several in situ studies have revealed spatiotemporal dynamics on heterogeneous catalysts surfaces under chemical stimuli1-4, which presumably control the activity, selectivity, and productivity5-11. However, operando validations of sufficient spacetime resolution12 are often missing, and hence, the effect of these dynamics on catalytic performance may not be entirely clear. Here, using dry reforming of methane over Ni as an example, we demonstrate the relevance of catalytic redox dynamics for reaction performance and determine their genesis from adaptive chemistry and continual catalytic cycling. By combining operando scanning electron microscopy and near-ambient-pressure X-ray photoelectron spectroscopy, we found that activation sites for methane and carbon dioxide differed but continually transformed into each other during the reaction. This behavior enabled a self-sustained oscillating regime evincing the sequential formation of active sites. We also found that not all spatiotemporal dynamics accounted for the catalytic function. We highlight the importance of oscillating reactions for mechanistic studies and propose that the generation of mechanical strain at the catalyst during redox cycling acted as a feedback element for the oscillations. These observations lead to deeper understanding of fundamental catalysis and open new opportunities for tuning catalytic performances
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