Cure kinetics,glass transition temperature development,and dielectric spectroscopy of a low temperature cure epoxy/amine system

This article reports a study of the chemical cure kinetics and the development of glass transition temperature of a low temperature (40°C) curing epoxy system (MY 750/HY 5922). Differential scanning calorimetry, temperature modulated differential scanning calorimetry, and dielectric spectroscopy were utilized to characterize the curing reaction and the development of the cross‐linking network. A phenomenological model based on a double autocatalytic chemical kinetics expression was developed to simulate the cure kinetics behavior of the system, while the dependence of the glass transition temperature on the degree of cure was found to be described adequately by the Di Benedetto equation. The resulting cure kinetics showed good agreement with the experimental data under both dynamic and isothermal heating conditions with an average error in reaction rate of less than 2 × 10^?3 min^?1. A comparison of the dielectric response of the resin with cure kinetics showed a close correspondence between the imaginary impedance maximum and the calorimetric progress of reaction. Thus, it is demonstrated that cure kinetics modeling and monitoring procedures developed for aerospace grade epoxies are fully applicable to the study of low temperature curing epoxy resins. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Impact of irradiation on fish and seafood shelf life: a comprehensive review of applications and irradiation detection

Irradiation is one of the most important and effective methods towards food preservation despite the consumer lack of trust and aversion towards this method. Irradiation effectiveness greatly depends on the dose provided to food. This review aims at summarizing all available information regarding the impact of irradiation dose on the shelf life and microflora and sensory and physical properties of fish, shellfish, molluscs, and crustaceans. The synergistic effect of irradiation in conjunction with other techniques such as salting, smoking, freezing, and vacuum packaging was also reported. Another issue covered within the frame of this review is the detection (comparison of methods in terms of their effectiveness and validity) of irradiated fish and seafood. The information related to fish and seafood irradiation and its detection is presented by means of 11 comprehensive tables and 9 figures.     

Assessing the sustainability of the UK society using thermodynamic concepts: Part 2

By building on the first part of our analysis, this second part attempts to provide a further understanding of the UK society's metabolism, its impact and offer policy suggestions that could promote a shift towards sustainability. The methodologies employed in this second part include Exergy Analysis (EA) and Extended Exergy Analysis (EEA). Exergy inputs and outputs amounted to 17423.9 and 11888.7 PJ, respectively, with energy carries, mainly fossil fuels, being both the predominant inputs (15597.1 PJ) and outputs (5147.1 PJ). Exergy consumption and efficiency for various economic sectors and subsectors have been calculated with the residential and service sector showing the lowest exergy conversion efficiencies (11.2% and 12.3%, respectively) while certain industrial subsectors, such as the aluminium and iron/steel industries showed the highest exergy conversion factors (67.0 and 62.1%). Extended exergy efficiencies were somewhat different owing to the different calculation procedure. Extended exergy efficiencies were 91.4% for the extraction sector, 38.9% for the conversion sector, 49.1% for the agriculture sector, 31.5% for the transportation sector, 38.6% for the industrial sector and 80.0% for the tertiary sector.     

The impact of Energy Performance Certificates on building deep energy renovation targets

The purpose of this paper is to investigate the effect of Energy Performance Certificates (EPCs) on the renovation of buildings. Thus, through the European project ENERFUND, 2 online web-based surveys were conducted in 12 countries of the European Union. It was shown that the results varied significantly both between countries and age groups and, that, on average, EPCs did play a role both in renovation decisions and whether to rent/buy a certain flat. In addition, this paper presents major key drivers and parameters related to energy renovation investment mobilisation and suggests actions that can contribute to the promotion of investments for deep energy renovation of buildings. Furthermore, it highlights potential benefits and effectiveness of using retrofitting online tools, such as the ENERFUND tool, pinpoints market failures in the building sector and provides suggestions on increasing the deep energy renovation market in Europe.     

Retrofitting solutions for two different occupancy levels of educational buildings in tropics

Within the multi-functionality of educational buildings, the energy conservation potential can be very different. In addition, among different retrofitting solutions investigated involving interventions on the building envelope, ventilation strategies, artificial lighting systems as well as equipment upgrading, different saving potential would come from different aspects. The opportunities for energy saving potential from the overall point of view and from the detailed aspect view of different retrofitting solutions would be very useful and important for building renovation decision making. This study presents a detailed retrofitting study of two different educational buildings. One represents a building with average occupancy variation and containing mainly offices and labs. The other one represents a building with high occupancy variation and containing mainly lecture rooms and studios. This comparison of the results gives an idea of the different energy saving potential for different types of educational buildings. Principal component analysis is also adopted to investigate the detailed performance of one of the buildings which is influenced stronger by these retrofitting solutions.     

Inorganic polymeric materials for passive fire protection of underground constructions

Protection against fire for reinforced concrete constructions is of great importance worldwide. There is a general perception that concrete structures are incombustible and thus, they have good fire‐resistance properties. In a real fire incident, however, concrete can be subjected to excess temperatures causing severe spalling and serious damage to concrete structures with significant economic cost and high potential risk to human life safety. Although a variety of fire‐protection methods exist, there is always a need for the development of new materials with improved thermophysical properties and low cost. Inorganic polymeric materials are promising from this point of view. They are incombustible, combining excellent physical, chemical, mechanical and thermal properties with low production cost and significant environmental benefits. In this work, the thermophysical properties of ferronickel slag‐based inorganic polymeric materials are studied. The results from the laboratory scale experiments are promising and indicative of the large‐scale behavior of material. The effectiveness of this material has to be proved in large‐scale experiments at higher temperatures simulating several severe fire scenarios as well as under all kinds of mechanical loading before concluding for its applicability as a fire protection system. Copyright © 2012 John Wiley & Sons, Ltd.     

The Impact of Angiogenesis in the Most Common Salivary Gland Malignant Tumors

Salivary gland carcinomas (SGCs) represent a group of rare tumors, with complete surgical resection being the main treatment option. Therapeutic armory for cases of locally aggressive, recurrent, and/or metastatic SGCs, though, remains poor since they exhibit high rates of resistance to systematic therapy. Angiogenesis is considered one of the contemporary hallmarks of cancer and anti-angiogenic factors have already been approved for the treatment of several cancer types. This review aims to summarize, in a histotype-specific manner, the most current available data on the angiogenic factors implicated in SGC angiogenesis, in order to highlight the differences between the most common SGC histotypes and the factors that may have a potential role as therapeutic targets.     

Cone Calorimeter and Thermogravimetric Analysis of Glass Phenolic Composites Used in Aircraft Applications

The increasing use of composite materials in aircraft cabins and structures poses significant challenges in order to maintain and improve the fire safety of aviation. In this work, the flammability characteristics of a commercial glass-fibre reinforced phenolic composite (GFRP) used for aircraft cabin partitions and furnishing are investigated experimentally. Thermogravimetric analysis under inert atmosphere at several heating rates provided information on the thermal decomposition process. The degradation process is modelled with one and two-step mechanisms using the Ozawa–Flynn–Wall iso-conversional method and the GPYRO numerical code which utilizes a genetic algorithm optimization scheme. The estimated activation energy and pre-exponential factor values, especially in the two-step case (77.18 and 104.69 kJ/mol and 2.60 × 106 and 3.19 × 106 min−1 for the first and the second step respectively), recover reasonably well the conversion degree and its derivative. Tests with a cone calorimeter (CC), performed at different incident heat fluxes, provided information on the reaction to fire characteristics of the material and the influence of the heat flux on the combustion process. In general, combustion proceeds in two stages, flaming and smoldering combustion. The CC results assisted by scanning electron microscopy photos provide information on the charring characteristics of the material. The critical heat flux for ignition and the corresponding ignition temperature are estimated, correlating heat fluxes with time to ignition. Thermally thin and thick models are considered, as well as a modified technique bridging the gap between these limit cases and therefore valid for thermally thin and thick but also intermediate conditions (more pertinent in the present case). The results for this latter approach are $$dot{q}^{primeprime}_{ig,cr}$$ ~ 20 kW/m2 and Tig = 469°C, providing also complementing information on thermophysical properties, such as thermal diffusivity, α = 1.23 × 10−7 m2/s, thermal conductivity, k = 0.325 W/(m K) and specific heat capacity, c = 1.330 kJ/(kg K). This work provides information on the reaction to fire characteristics of GFRP, but also on physical and flammability properties in a form suitable to be used in numerical codes, for the prediction of fire and evacuation scenarios. The influence of the reinforcement structure on the fire behaviour of the composite is also illustrated and discussed.