The combustion behavior of epoxy-based multifunctional electrolytes

Multifunctional or structural electrolytes are characterized by ionic conductivity high enough to be used in the electrochemical devices and mechanical performance suitable for the structural applications. Preliminary insights are provided into the combustion behavior of structural bi-continuous electrolytes based on bisphenol A diglycidyl ether (DGEBA), synthesized using the techniques of reaction induced phase separation and emulsion templating. The effect of the composition of the structural electrolytes and external heat flux on the behavior of the formulations were studied using a cone calorimeter with gases formed during testing analyzed using FTIR. The composition of the formulations investigated was changed by varying the type and amount of the ion conductive part of the bi-continuous electrolyte. Two ionic liquids, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIM-TFSI) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF₄), as well as a deep eutectic solvent (DES) based on ethylene glycol and choline chloride, were used. The results obtained confirm that time to ignition, heat release rate (HRR), total mass loss, as well as the composition of the gases released during tests depend on the composition of the formulations. Addition of liquid electrolyte is found to reduce the time to ignition by up to 10% and the burning time by between 28% and 60% with the added benefit of reducing the HRR by at least 34%. Gaseous products such as CO₂, CO, H₂O, CH₄, C₂H₂, N₂O, NO, and HCN were detected for all formulations with the gases SO₂, NH₃, HCl, C₂H₄, and NH₃ found to be for certain formulations only.     

Concurrent software verification with states, events, and deadlocks

We present a framework for model checking concurrent software systems which incorporates both states and events. Contrary to other state/event approaches, our work also integrates two powerful verification techniques, counterexample-guided abstraction refinement and compositional reasoning. Our specification language is a state/event extension of linear temporal logic, and allows us to express many properties of software in a concise and intuitive manner. We show how standard automata-theoretic LTL model checking algorithms can be ported to our framework at no extra cost, enabling us to directly benefit from the large body of research on efficient LTL verification. We also present an algorithm to detect deadlocks in concurrent message-passing programs. Deadlock- freedom is not only an important and desirable property in its own right, but is also a prerequisite for the soundness of our model checking algorithm. Even though deadlock is inherently non-compositional and is not preserved by classical abstractions, our iterative algorithm employs both (non-standard) abstractions and compositional reasoning to alleviate the state-space explosion problem. The resulting framework differs in key respects from other instances of the counterexample-guided abstraction refinement paradigm found in the literature. We have implemented this work in the magic verification tool for concurrent C programs and performed tests on a broad set of benchmarks. Our experiments show that this new approach not only eases the writing of specifications, but also yields important gains both in space and in time during verification. In certain cases, we even encountered specifications that could not be verified using traditional pure event-based or state-based approaches, but became tractable within our state/event framework. We also recorded substantial reductions in time and memory consumption when performing deadlock-freedom checks with our new abstractions. Finally, we report two bugs (including a deadlock) in the source code of Micro-C/OS versions 2.0 and 2.7, which we discovered during our experiments. This research was sponsored by the National Science Foundation (NSF) under grants no. CCR-9803774 and CCR-0121547, the Office of Naval Research (ONR) and the Naval Research Laboratory (NRL) under contract no. N00014-01-1-0796, the Army Research Office (ARO) under contract no. DAAD19-01-1-0485, and was conducted as part of the Predictable Assembly from Certifiable Components (PACC) project at the Software Engineering Institute (SEI). This article combines and builds upon the papers (CCO⁺04) and (CCOS04). Received December 2004 Revised July 2005 Accepted July 2005 by Eerke A. Boiten, John Derrick, Graeme Smith and Ian Hayes     

Integration of radar and Landsat-derived foliage projected cover for woody regrowth mapping, Queensland, Australia

In Queensland, Australia, forest areas are discriminated from non-forest by applying a threshold (∼ 12%) to Landsat-derived Foliage Projected Cover (FPC) layers (equating to ∼ 20% canopy cover), which are produced routinely for the State. However, separation of woody regrowth following agricultural clearing cannot be undertaken with confidence, and is therefore not mapped routinely by State Agencies. Using fully polarimetric C-, L- and P-band NASA AIRSAR and Landsat FPC data for forests and agricultural land near Injune, central Queensland, we corroborate that woody regrowth dominated by Brigalow (Acacia harpophylla) cannot be discriminated using either FPC or indeed C-band data alone, because the rapid attainment of a canopy cover leads to similarities in both reflectance and backscatter with remnant forest. We also show that regrowth cannot be discriminated from non-forest areas using either L-band or P-band data alone. However, mapping can be achieved by thresholding and intersecting these layers, as regrowth is unique in supporting both a high FPC (> ∼ 12%) and C-band SAR backscatter (> ~ − 18 dB at HV polarisation) and low L-band and P-band SAR backscatter (e.g. < =∼ 14 dB at L-band HH polarisation). To provide a theoretical explanation, a wave scattering model based on that of Durden et al. [Durden, S.L., Van Zyl, J.J. & Zebker, H.A. (1989). Modelling and observation of radar polarization signature of forested areas. IEEE Trans. Geoscience and Remote Sensing, 27, 290-301.] was used to demonstrate that volume scattering from leaves and small branches in the upper canopy leads to increases in C-band backscattering (particularly HV polarisations) from regrowth, which increases proportionally with FPC. By contrast, low L-band and P-band backscatter occurs because of the lack of double bounce interactions at co-polarisations (particularly HH) and volume scattering at HV polarisation from the stems and branches, respectively, when their dimensions are smaller than the wavelength. Regrowth maps generated by applying simple thresholds to both FPC and AIRSAR L-band data showed a very close correspondence with those mapped using same-date 2.5 m Hymap data and an average 73.7% overlap with those mapped through time-series comparison of Landsat-derived land cover classifications. Regrowth mapped using Landsat-derived FPC from 1995 and JER-1 SAR data from 1994-1995 also corresponded with areas identified within the time-series classification and true colour stereo photographs for the same period. The integration of Landsat FPC and L-band SAR data is therefore expected to facilitate regrowth mapping across Queensland and other regions of Australia, particularly as Japan's Advanced Land Observing System (ALOS) Phase Arrayed L-band SAR (PALSAR), to be launched in 2006, will observe at both L-band HH and HV polarisations.     

Determination of the formation constant of ATP—cobalt(II) complex(ATP—Co)2− by A′pH stat′ titration method

A technique of pH titration is used for the study of the formation of the ATP Co^2? complex at diverse temperatures. The stability constants, as also the corresponding thermodynamic quantities, obtained for an ionic strength 0.2 in tetramethylammonium bromide are reported and compared with these of ATP Mn^2? and ATP Mg^2? complexes.     

State Space Search with Prioritised Soft Constraints

This paper addresses two issues: how to choose between solutions for a problem specified by multiple criteria, and how to search for solutions in such situations. We argue against an approach common in decision theory, reducing several criteria to a single cost (e.g., using a weighted sum cost function) and instead propose a way of partially ordering solutions satisfying a set of prioritised soft constraints. We describe a generalisation of the A^* search algorithm which uses this ordering and prove that under certain reasonable assumptions the algorithm is complete and optimal.     

Influence diagnostics in log-Birnbaum-Saunders regression models with censored data

In this paper we discuss log-Birnbaum-Saunders regression models with censored observations. This kind of model has been largely applied to study material lifetime subject to failure or stress. The score functions and observed Fisher information matrix are given as well as the process for estimating the regression coefficients and shape parameter is discussed. The normal curvatures of local influence are derived under various perturbation schemes and two deviance-type residuals are proposed to assess departures from the log-Birnbaum-Saunders error assumption as well as to detect outlying observations. Finally, a data set from the medical area is analyzed under log-Birnbaum-Saunders regression models. A diagnostic analysis is performed in order to select an appropriate model.     

What predicts psychological resilience after disaster? The role of demographics, resources, and life stress.

A growing body of evidence suggests that most adults exposed to potentially traumatic events are resilient. However, research on the factors that may promote or deter adult resilience has been limited. This study examined patterns of association between resilience and various sociocontextual factors. The authors used data from a random-digit-dial phone survey (N = 2,752) conducted in the New York City area after the September 11, 2001, terrorist attack. Resilience was defined as having 1 or 0 posttraumatic stress disorder symptoms and as being associated with low levels of depression and substance use. Multivariate analyses indicated that the prevalence of resilience was uniquely predicted by participant gender, age, race/ethnicity, education, level of trauma exposure, income change, social support, frequency of chronic disease, and recent and past life stressors. Implications for future research and intervention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defensive behavior and hippocampal cell proliferation: Differential modulation by naltrexone during stress.

The present study investigated the role of endogenous opioids in the expression of defensive behaviors (DBs) and the suppression of cell proliferation (CP) in the dentate gyrus (DG) induced by exposure to predator odor, trimethyl thiazoline (TMT). Adult male rats were injected with either naltrexone (an opioid antagonist, 5 mg/kg) or saline 30 min before exposure to either TMT or a control odor. Behavior was scored for the first 15 min of odor exposure. Bromodeoxyuridine (BrdU, 200 mg/kg) was then injected, and the rats were perfused 1 hr later. Exposure to TMT increased the expression of DBs and suppressed the number of proliferating cells in the DG. Pretreatment with naltrexone attenuated the effects of TMT on DB expression but did not attenuate the effects of TMT on CP. In addition, naltrexone administration suppressed CP in the absence of TMT. These results demonstrate a dissociation between DBs and regulation of CP in the DG. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forcing biological sciences into architectural design:On conceptual confusions in the field of biomimetic architecture

Certain confusion may be observed in the field of biomimetic architecture,as it emerges at the crossroad of two disciplinary domains:architectural design and bi...