Study of formulation variables of thermoplastic reflecting materials for traffic marking

Nine formulations of thermoplastic materials for traffic marking were prepared using a resin based on maleic anhydride modified with rosin in different proportions (18, 22 and 26%). As plasticizer a liquid coconut long oil alkyd resin (100% solids) was employed Hiding pigment was titanium dioxide; calcium carbonate and micronized tale were used as extenders. Coarse marble powder is used to facilítate the incorporation of glass beads. The operation was made employing a double Z mixer oil heated to obtain a mass temperature of 180-190 QC. The mixer was provided with two asynchronous arms rotating at 46 rpm. Dry and wet abrasión tests were carried out and the obtained results indicated that wearing valúes are three times greater in the case of the wet test. It is demonstrated that plasticization degree controls hardness variation as a function of temperature, determining a critical point which is the beginning of an abrupt reduction of hardness. Water absoption increases when plasticizer content increases. Matrix correlation of tests results was used to analize the obtained numeric valúes

Neuroacanthocytosis associated with a defect of the 4.1R membrane protein

BACKGROUND: Neuroacanthocytosis (NA) denotes a heterogeneous group of diseases that are characterized by nervous system abnormalities in association with acanthocytosis in the patients' blood. The 4.1R protein of the erythrocyte membrane is critical for the membrane-associated cytoskeleton structure and in central neurons it regulates the stabilization of AMPA receptors on the neuronal surface at the postsynaptic density. We report clinical, biochemical, and genetic features in four patients from four unrelated families with NA in order to explain the cause of morphological abnormalities and the relationship with neurodegenerative processes. CASE PRESENTATION: All patients were characterised by atypical NA with a novel alteration of the erythrocyte membrane: a 4.1R protein deficiency. The 4.1R protein content was significantly lower in patients (3.40 ± 0.42) than in controls (4.41 ± 0.40, P < 0.0001), reflecting weakened interactions of the cytoskeleton with the membrane. In patients IV:1 (RM23), IV:3 (RM15), and IV:6 (RM16) the 4.1 deficiency seemed to affect the horizontal interactions of spectrin and an impairment of the dimer self-association into tetramers was detected. In patient IV:1 (RM16) the 4.1 deficiency seemed to affect the skeletal attachment to membrane and the protein band 3 was partially reduced. CONCLUSION: A decreased expression pattern of the 4.1R protein was observed in the erythrocytes from patients with atypical NA, which might reflect the expression pattern in the central nervous system, especially basal ganglia, and might lead to dysfunction of AMPA-mediated glutamate transmission

Plasma response to fish oil in the elderly

Little information is available concerning whether incorporation of dietary omega-3 fatty acids into plasma lipids changes during healthy aging. Elderly (74 ± 4 years old) and young (24 ± 2 years old) adults were given a fish oil supplement for 3 weeks that provided 680 mg/day of docosahexaenoic acid and 320 mg/day of eicosapentaenoic acid, followed by a 2 week wash-out period. Compliance was monitored by spiking the capsules with carbon-13 glucose, the excretion of which was measured in breath CO2. In response to the supplement, plasma docosahexaenoic acid rose 42% more in the elderly but eicosapentaenoic responded similarly in both groups. Despite raising docosahexaenoic acid intake by five to tenfold, the supplement did not raise plasma free docosahexaenoic acid (% or mg/dL) in either group. We conclude that healthy aging is accompanied by subtle but significant changes in DHA incorporation into plasma lipids

Manual Ecomar de corrosión y protección

La mayor parte de los metales utilizables industrialmente sufren fenómenos de corrosión, es decir se deterioran o destruyen por la acción de medios agresivos de diferentes características. En la Armada existe una larga experieneia en la lucha contra la corrosión, por la agresividad del ambiente marino sobre los componentes estructurales de las unidades. Para cuantificar la importancia de es te problema sería necesaria una referencia económica concreta y ésta es difícil de establecer, por cuanto ademas de las pérdidas directas, que se refieren al valor de los materiales destruidos, hay una inmensa variedad de pérdidas indirectas, de difícil análisis. Entre estas últimas pueden citarse las siguientes: vidas humanas por accidentes catastróficos de los materiales estructurales, paralización del uso de sistemas por reparación, pérdida o contaminación de productos íntermedios o final es, aumento de consumo de energía, disminución de rendimiento como consecuencia de la modificación de las características hidrodinámicas de un buque por acumulación de productos de corrosión e incrustaciones. Es por estos motivos que la Armada Argentina, a través del Servicio Naval de Investigación y Desarrollo, decidió oportunamente apoyar las tareas de investigación que realizaban científicos de diferentes organismos (CNEA, CITEFA, INIFTA, CIDEPINT), brindando su aporte en forma de subsidios para que se efectivizara el PROGRAMA ECOMAR, interinstitucional y muítidisciplinario. Se orientaron así aquellos esfuerzos al estudio de la cor ros ion marina y su control. Hace más de un lustro que se está trabajando en el tema y son numerosas las publicaciones científicas y asesoramientos ya real izados. Muchos de los trabajos efectuados han sido presentados en reuniones científicas nacionales e internacionales. Además, en el año 1973, se publicó un tomo sobre CORROS ION MARINA, donde estos problemas fueron analizados exhaustivamente. Complementando esta tarea de transferencia de conocimientos, el SENID ha encarado la edición de este MANUAL ECOMAR DE CORROSIÓN Y PROTECCIÓN, donde se consideran casos de interés práctico y se procura, mediante un lenguaje sencillo, llegar al mayor número posible de interesados en el tema.Material digitalizado en SEDICI-CIC Digital gracias a la Biblioteca del Centro de Investigación y Desarrollo en Tecnología de Pinturas (CIDEPINT)

A Quantitative Test of Hamilton's Rule for the Evolution of Altruism

A study of experimental evolution in simulated groups of foraging robots demonstrates that their propensity to behave altruistically depends on their genetic relatedness (similarity), and the costs and benefits associated with altruistic behavior

La managerializzazione del rischio in sanità. Un nuovo mito razionale?

Nelle grandi narrazioni moderne il termine rischio diventa la chiave per accedere al controllo della propria esistenza e per affrontare attivamente gli eventi che non hanno un’apparente spiegazione razionale. Il rischio si lega al concetto di responsabilità umana e alla convinzione che vi si può sempre reagire, sviluppando delle opportune strategie tecniche, politiche e culturali per preservare la società dal disordine. Sul piano pratico la stretta relazione tra la filosofia del controllo della propria condotta e la gestione tecnica degli eventi incerti ha coinciso con l’applicazione del calcolo probabilistico al mercato delle imprese assicurative, uno di pilastri del comparto affaristico contemporaneo1, e ha avviato il processo scientifico di matematizzazione del rischio (Hutter, Power, 2005). Tale processo rimanda da un lato alla nozione di caso o di probabilità e dall’altro a quella di perdita o di danno, perché l’evento contro cui ci si assicura e contiene entrambi: il modello generale dell’assicurazione è il gioco d’azzardo. Un rischio, un incidente “è come un numero della roulette, una carta estratta dal mazzo. Con l’assicurazione il gioco d’azzardo diventa un simbolo del mondo (Lupton, 2003)”

Benchmarking aerial robots for inspection of power and petrochemical facilities

This paper collects and analyzes a list of application scenarios for inspections of power generation and petrochemical processing facilities using unmanned aerial vehicles. Based on this list of applications, general requirements for future aerial inspection robots are derived to serve as potential benchmarks for further research and development in this field. In this context the paper also discusses the need for unmanned aerial vehicles not only capable of pure visual inspections but also providing the means for inspection by contact