Innovative polyelectrolytes/poly(ionic liquid)s for energy and the environment

This paper presents the work carried out within the European project RENAISSANCE‐ITN, which was dedicated to the development of innovative polyelectrolytes for energy and environmental applications. Within the project different types of innovative polyelectrolytes were synthesized such as poly(ionic liquid)s coming from renewable or natural ions, thiazolium cations, catechol functionalities or from a new generation of cheap deep eutectic monomers. Further, macromolecular architectures such as new poly(ionic liquid) block copolymers and new (semi)conducting polymer/polyelectrolyte complexes were also developed. As the final goal, the application of these innovative polymers in energy and the environment was investigated. Important advances in energy storage technologies included the development of new carbonaceous materials, new lignin/conducting polymer biopolymer electrodes, new iongels and single‐ion conducting polymer electrolytes for supercapacitors and batteries and new poly(ionic liquid) binders for batteries. On the other hand, the use of innovative polyelectrolytes in sustainable environmental technologies led to the development of new liquid and dry water, new materials for water cleaning technologies such as flocculants, oil absorbers, new recyclable organocatalyst platforms and new multifunctional polymer coatings with antifouling and antimicrobial properties. All in all this paper demonstrates the potential of poly(ionic liquid)s for high‐value applications in energy and enviromental areas. © 2017 Society of Chemical Industry     

Early width estimation of fragmented JPEG with corrupted header

In transformed and compressed domain fragmented files are very difficult to recover using conventional file recovery software. JPEG images are forensically important file format due to its popularity in a wide area of applications. In JPEG compression the header keeps important parameters that are required to decode the image back to pixel domain. In this paper the detection of width and height of an image from the JPEG stream is improved with less assumptions than previous papers. In the old approaches it was assumed that information about the image like Huffman table, Reset (RST) value and Quantization table were readily available for the techniques to work. However, in this paper the width is extracted from the quantized AC values that reduce the assumptions to just Huffman table.     

Vulnerability of smallholder rural households to food insecurity in Eastern Ethiopia

Although several empirical methodologies as to how best assess vulnerability to food insecurity have been proposed in the literature, none of these has evolved into a unanimously accepted approach. This article contributes to this literature by adapting the Vulnerability as Expected Poverty approach from poverty analysis methodology with the aim of scrutinizing factors determining household level vulnerability to food insecurity based on cross-section data collected from 277 randomly selected households in eastern Ethiopia. Vulnerability to food insecurity was strongly associated with several factors which included family size, size of cultivated landholding, soil fertility status of plots, access to irrigation, number of extension visits, use of fertilizer and improved seed. The probability that any given household??s food consumption expenditure would fall below a specified cut-off level has also been computed and vulnerable households identified. The total number of vulnerable households (111) was found to be greater than those who are currently food insecure (103). This implies that design and implementation of food security policies and strategies need to focus not only on those who are observed to be currently food insecure, but also on setting up social protection mechanisms to help prevent households from falling more deeply into food insecurity in the future.     

Dynamic Response of Retrofitted Masonry Walls for Blast Loading

A full-scale blast test was conducted on eight masonry walls reinforced with two and four layers of carbon fibers and two types of polymer matrices. The walls were then subjected to a 0.45-kg pentolite booster suspended from the ceiling of a test structure. The pressure-time history caused by the blast and the resulting displacement response were measured during the test. This paper presents a summary of the test program and the corresponding results from a nonlinear single degree of freedom analysis. The results provide a basis for determining effective means of retrofitting existing masonry walls and designing new structures to withstand blast loads. The paper also outlines a fiber-reinforced polymer retrofit design procedure for walls subjected to blast loading.     

Quasi-Balanced Failure Approach for Evaluating Moment Capacity of FRP Underreinforced Concrete Beams

Failure of concrete beam sections underreinforced with fiber-reinforced polymer (FRP) is initiated by FRP rupture before concrete crushing. In such a case, the typical rectangular stress block based on the balanced failure mechanism may not apply. In the present study, rigorous sectional analyses are performed implementing existing concrete stress-strain models for a wide range of values of design parameters. Based on the results of the numerical analyses, the variation of parameters of equivalent stress block of concrete was investigated, and an alternative, yet simple, design method for evaluating moment-carrying capacity of FRP underreinforced concrete beam using quasi-balanced failure approach was developed. The proposed design method was verified by comparing the predicted moment-carrying capacity with existing test results.     

Full-Scale Testing and Analysis for Blast-Resistant Design

A full-scale blast test was conducted on a structure representing a mailroom, constructed with unreinforced masonry walls. The four walls were retrofitted with different quantities of glass fiber-reinforced polymers (GFRP) on the outside face to increase their resistance to the blast load. In addition, shotcrete was added to the inside face of the two long walls. The objective of this test was to validate a method of analysis that can be used to design effective retrofit techniques to contain blast loads. A blast load was produced by the detonation of a 0.91?kg (2?lb) equivalent TNT charge placed near the center of the room. Instrumentation on individual walls monitored the blast pressure and the consequent displacement and velocity of the walls. Although the walls sustained extensive internal damage and plastic deformation, the retrofit was able to withstand the blast load. It was observed through the postmortem analysis of the test that the stiffness of the walls is completely lost at an early stage and only membrane action of the GFRP provides structural resistance.