Friction induced paint damage as affected by clearcoat chemistry

One form of damage to automotive painted plastic composites, in particular thermoplastic bumpers and fascias, is known to be caused from compressive shear loading placed on the surface of the composite. The loading inflicted upon the composite by a stationary force (e.g. an automobile hitting a post) or a moving object (e.g. an automobile hitting another automobile), and consequent compressive shear that is induced, can result in cohesive delamination of the substrate. The cohesive delamination in the painted composite (herein referred to as ‘gouge') is not only influenced by the cohesive strength of the substrate but also by the mechanical properties of the coating. Our studies indicate that one important attribute of the coating, namely the coating's coefficient of friction, can significantly impact the ‘gouge' resistance of the painted composite. In this work, we will describe the derivation of coating attributes as they affect ‘gouge' resistance and relate changes in the coating chemistry to useful life parameters.     

The enzymology of sludge solubilisation utilising sulphate-reducing systems: the properties of lipases

The first stage in the degradation and recycling of particulate organic matter is the solubilisation and enhanced hydrolysis of complex polymeric organic carbon structures associated with the sulphidogenic environment. An investigation into the enzymology of these processes has shown that lipase enzyme activities were found predominantly associated with the organic particulate matter of the sewage sludge. Sonication of the sludge gave an increase in enzyme activity as the enzymes were released into the supernatant. pH and temperature optimisation studies showed optima between 6.5 and 8 and 50-60 degrees C, respectively. All the lipase enzymes from the methanogenic bioreactors indicated extensive stability for at least an hour at their respective optimum temperatures and pH; sulphidogenic lipases reflected limited stability at these temperatures and pH during this time period. Though sulphate showed inhibitory properties towards lipases both sulphide and sulphite appeared to enhance the activity of the enzymes. It is argued that these sulphur species, liberated at different times during the sulphate reduction process, disrupt the integrity of the organic particulate floc by neutralising acidic components on the surface. The release of further entrapped enzymes from the organic particulate matter result in a subsequent enhancement of hydrolysis of polymeric material.     

Dysregulation of Astrocyte Ion Homeostasis and Its Relevance for Stroke-Induced Brain Damage

Ischemic stroke is a leading cause of mortality and chronic disability. Either recovery or progression towards irreversible failure of neurons and astrocytes occurs within minutes to days, depending on remaining perfusion levels. Initial damage arises from energy depletion resulting in a failure to maintain homeostasis and ion gradients between extra- and intracellular spaces. Astrocytes play a key role in these processes and are thus central players in the dynamics towards recovery or progression of stroke-induced brain damage. Here, we present a synopsis of the pivotal functions of astrocytes at the tripartite synapse, which form the basis of physiological brain functioning. We summarize the evidence of astrocytic failure and its consequences under ischemic conditions. Special emphasis is put on the homeostasis and stroke-induced dysregulation of the major monovalent ions, namely Na⁺, K⁺, H⁺, and Cl⁻, and their involvement in maintenance of cellular volume and generation of cerebral edema.     

Quality and psychosocial factors influencing purchase of orange-fleshed sweetpotato bread

This 2018 study, conducted in six Tusky's supermarkets in Nairobi, Kenya, combined the Just-About-Right, Penalty and Mean-End-Chain analyses to examine the quality and psychosocial factors influencing the purchase of a novel bread made from orange-fleshed sweet potato (OFSP), a biofortified crop, focusing on sixty-one male and eighty female urban OFSP bread buyers recruited at point of purchase. It finds that sensory and psychosocial factors drive purchasing decisions and that some of the bread's sensory characteristics are misaligned with consumers' expectations. It also finds that women and men’s evaluations of the bread's characteristics are different, as are their motivations for purchase. However, good sensory attributes and the knowledge of the bread's nutritional value were key drivers. Some misaligned characteristics reveal levers for the reformulation of the bread and present opportunities for segmenting the market. Several other implications of the findings for policy and future improvement of the bread are discussed.     

Image encryption method based on improved ECC and modified AES algorithm

Multimedia Tools and Applications - Currently, embedded systems can be found everywhere in quotidian life. In the development of embedded systems, information security is one of the important...     

Occurrence of rotaviruses and enteroviruses in recreational waters of Oak Creek, Arizona

Recent epidemiological studies have shown a relationship between swimming in recreational waters meeting bacteriological standards and gastroenteritis with a suggested viral etiology. No previous studies have been conducted in the United States on the occurrence of human pathogenic enteric viruses in freshwater recreational areas. The presence of enteroviruses and rotaviruses was investigated in Oak Creek, Arizona, a heavily used recreational area. Water samples were filtered through positively charged filters (168–1555 I.), eluted with beef extract, and assayed for human enteroviruses and rotaviruses. Eighteen of the 41 recreational water samples were positive for enterovirus or rotavirus. Of these, nine samples exceeded the Arizona State recommended limit of 1 PFU 40 l⁻¹ for full body contact in effluent dominated recreational waters. Several virus positive samples met the recommended fecal coliform standards (200 CFU 100 ml⁻¹) for recreational waters indicating the inadequacy of bacterial standards for monitoring viral water quality. The isolation of the pathogenic enteric viruses (i.e., poliovirus 1, echovirus 1, coxsackievirus B1 and B6 and rotavirus) from this popular recreational water demonstrates the potential for transmission of viral disease.