New Zealand contributions to the global earthquake model’s earthquake consequences database (GEMECD)

The Global Earthquake Model’s (GEM) Earthquake Consequences Database (GEMECD) aims to develop, for the first time, a standardised framework for collecting and collating geocoded consequence data induced by primary and secondary seismic hazards to different types of buildings, critical facilities, infrastructure and population, and relate this data to estimated ground motion intensity via the USGS ShakeMap Atlas. New Zealand is a partner of the GEMECD consortium and to-date has contributed with 7 events to the database, of which 4 are localised in the South Pacific area (Newcastle 1989; Luzon 1990; South of Java 2006 and Samoa Islands 2009) and 3 are NZ-specific events (Edgecumbe 1987; Darfield 2010 and Christchurch 2011). This contribution to GEMECD represented a unique opportunity for collating, comparing and reviewing existing damage datasets and harmonising them into a common, openly accessible and standardised database, from where the seismic performance of New Zealand buildings can be comparatively assessed. This paper firstly provides an overview of the GEMECD database structure, including taxonomies and guidelines to collect and report on earthquake-induced consequence data. Secondly, the paper presents a summary of the studies implemented for the 7 events, with particular focus on the Darfield (2010) and Christchurch (2011) earthquakes. Finally, examples of specific outcomes and potentials for NZ from using and processing GEMECD are presented, including: 1) the rationale for adopting the GEM taxonomy in NZ and any need for introducing NZ-specific attributes; 2) a complete overview of the building typological distribution in the Christchurch CBD prior to the Canterbury earthquakes and 3) some initial correlations between the level and extent of earthquake-induced physical damage to buildings, building safety/accessibility issues and the induced human casualtie

Unraveling the Effect of Carbon Nanotube Oxidation on Solid-State Decomposition of Ammonia Borane/Carbon Nanotube Composites

Among the routes to perform hydrogen release from ammonia in solid state, the nanoconfinement into a carbonaceous matrix or the use of carbon-supported catalysts for the thermal degradation of ammonia borane (AB) is the most interesting one. Oxidized carbon nanotubes (CNTs) represent a suitable choice for preparing AB mixtures or for anchoring catalysts for dehydrogenation. Nevertheless, literature lacks detailed study about the influence of CNT oxidation degree on the AB degradation/hydrogen release. In this study, we first described in a comprehensive way that the thermal degradation of AB mixed with CNTs by varying the CNT oxidation degree enlightens the degradative routes mainly active in each case. Using highly oxidized CNTs, we observed a decrement of activation energy of the degradative process up to around 53% and the activation/suppression of different pathways based on the amount of oxygen functionalities present in the mixtures. Furthermore, the presence of oxidized CNTs modulated the solid-state reactivity of AB reducing the release of nitrogen/boron species together with hydrogen. These findings lead the way for the design of new hydrogen storage materials

MWNT Surface Self-Assembling in Fire Retardant Polyethylene-Carbon nanotubes nanocomposites

Multiwall carbon nanotubes (MWNT) were melt blended at different concentration with linear low density polyethylene (LLDPE). The nanotubes impart the fire-retardant characteristics to the polymer by formation of a thin protective film of MWNT/carbon char generated on the surface of the nanocomposites. The film formation mechanism is discussed

Experimental Investigation on Thermal Diffusivity of PM Steels

The scanty literature data on thermal diffusivity of P/M steels seems contradictory, if the cooling speed on quenching is the evaluation parameter. Due to the basic importance of diffusivity on the response of P/M steels to heat-treating, an experimental survey has been carried out, to collect data on various P/M steels, based on prealloyed, or diffusion-bonded, or admixed powders. The study has also covered the influence of processing parameters, such as compaction pressure and sintering temperature. The flash method has been used to measure the thermal diffusivity of P/M steels. This method directly measures the thermal diffusivity of a sample in slab shape. A plane-parallel sample is inserted in the test apparatus and then a short light pulse, produced by a laser or a flash lamp, heats the front surface of the sample. The heat diffuses through the sample, leading to a temperature rise on the sample rear surface. An infrared detector measures this temperature rise, versus time, and thermal diffusivity is derived from the least square regression on the whole temperature trend, using the analytical solution of heat conduction. The results show that thermal diffusivity increases as density increases. This achievement can be justified by a simple theoretical analysis of the thermal conductivity on thermal diffusivity. The collected data also enable us to ascertain the influence of sintered material composition and carbon content on thermal diffusivity. The results should contribute to clarify some uncertainties and perplexities on the behavior of properly elaborated P/M steels, to be hardened by heat treatment, conventional – such as oil quenching – or innovative, such as sinter -hardening

Highly Dispersed Few-Nanometer Chlorine-Doped SnO2 Catalyst Embedded in a Polyaniline Matrix for Stable HCOO– Production in a Flow Cell

With the spread of alternative energy plants, electrolysis processes are becoming the protagonists of the future industrial generation. The technology readiness level for the electrochemical reduction of carbon dioxide is still low and is largely based on precious metal resources. In the present work, tin ions are anchored on a polyaniline matrix, via a sonochemical synthesis, forming a few atomic layers of chlorine-doped SnO2 with a total loading of tin atom load of only 7 wt %. This catalyst is able to produce formate (HCOO-) with great selectivity, exceeding 72% of Faradaic efficiency in the first hour of testing in 1 M KHCO3 electrolyte, with a current density of more than 50 mA cm-2 in a 2 M KHCO3 electrolyte flow cell setup. Catalyst stability tests show a stable production of HCOO- during 6 h of measurement, accumulating an overall TONHCOO- of more than 10,000 after 16 h of continuous formate production. This strategy is competitive in drastically reducing the amount of metal required for the overall catalysis

Aqueous phase reforming of the residual waters derived from lignin-rich hydrothermal liquefaction: investigation of representative organic compounds and actual biorefinery streams

Secondary streams in biorefineries need to be valorized to improve the economic and environmental sustainability of the plants. Representative model compounds of the water fraction from the hydrothermal liquefaction (HTL) of biomass were subjected to aqueous phase reforming (APR) to produce hydrogen. Carboxylic and bicarboxylic acids, hydroxyacids, alcohols, cycloketones and aromatics were identified as model compounds and tested for APR. The tests were performed with a Pt/C catalyst and the influence of the carbon concentration (0.3–1.8 wt. C%) was investigated. Typically, the increase of the concentration negatively affected the conversion of the feed toward gaseous products, without influencing the selectivity toward hydrogen production. A synthetic ternary mixture (glycolic acid, acetic acid, lactic acid) was subjected to APR to evaluate any differences in performance compared to the tests with single compounds. Indeed, glycolic acid reacted faster in the mixture than in the corresponding single compound test, while acetic acid remained almost unconverted. The influence of the reaction time, temperature and carbon concentration was also evaluated. Finally, residual water resulting from the HTL of a lignin-rich stream originating from an industrial-scale lignocellulosic ethanol process was tested for the first time, after a thorough characterization. In this framework, the stability of the catalyst was studied and found to be correlated to the presence of aromatics in the aqueous feedstock. For this reason, the influence of an extraction procedure for the selective removal of these compounds was explored, leading to an improvement in the APR performance

Inkjet printed doped polyaniline: navigating through physics and chemistry for the next generation devices

Innovative benzidine-free PANI-based inks for electrically conducive inkjet printed devices were developed and tested and the results compared with those obtained by traditional PANI. NMR investigations evidenced the presence of quinones and phenolic groups on the backbone of the innovative PANIs that are thought being responsible for the higher solubility in DMSO. A mechanism of reaction was proposed. The numerous characterizations (NMR, UV-Vis, FTIR, XPS and electrical investigations) allowed to compare protonation level, doping level, valence band maximum for both the type of PANI. The correlation among structural properties, printability, conductivity and solubility was discussed