RESUMEN
A method for the determination of the intermetallic diffusion coefficient in the Cu-Au system is described based on energy dispersive X-ray techniques. XRF and EDS analysis were used to measure the thickness of the electroplated gold coating and the copper diffused through it, respectively. This information was used to obtain the diffusion coefficient through an equation based on Fick's law. Colour measurements and metallographic section analysis of the samples were also performed to evaluate alternative methods for a qualitative determination of diffusion rate. The thickness of the gold layer was chosen in agreement with what is used in decorative and functional applications (<1 µm). The measurements were performed on samples heated in a range of temperatures between 100 °C and 200 °C from 12 to 96 h. The results obtained follow a linear trend between the logarithm of the diffusion coefficient and the inverse of the temperature and are in line with the values found in the literature.
Asunto(s)
Cobre , Oro , Microanálisis por Sonda Electrónica/métodos , Difusión , CalorRESUMEN
The main goal of this work is to open new perspectives in the field of electrodeposition and provide green alternatives to the electroplating industry. The effect of different anions (SO42-, ClO3-, NO3-, ClO4-, BF4-, PF6-) in solution on the electrodeposition of copper was investigated. The solutions, containing only the copper precursor and the background electrolyte, were tailored to minimize the environmental impact and reduce the use of organic additives and surfactants. The study is based on electrochemical measurements carried out to verify that no metal complexation takes place. We assessed the nucleation and growth mechanism, we performed a morphological characterization through scanning electron microscopy and deposition efficiency by measuring the film thickness through X-ray fluorescence spectroscopy. Significant differences in the growth mechanism and in the morphology of the electrodeposited films, were observed as a function of the background electrolyte.
Asunto(s)
Cobre , Galvanoplastia , Cobre/química , Galvanoplastia/métodos , Microscopía Electrónica de Rastreo , Aniones , Electrólitos/químicaRESUMEN
Human cerebral organoids (HCOs) are miniature brains cultivated in a dish using pluripotent human cells that, thanks to advanced technologies, tend to reproduce the development path of the brain of an embryo in the mother's uterus. Recent data from studies carried out in different laboratories have indicated that HCOs show complex electrical activity, are receptive to light stimuli, and can command a muscle connected to them. The presence of the main neuronal structures in them suggests that, despite currently lacking vascularization and sensory exchanges with the outside world, more developed HCOs could exhibit some rudimentary form of consciousness, specifically a minimal sentience with respect to the basic experiences of pain and pleasure. Faced with this possibility, which for many scientists is still a long way off, we have begun to reflect on how we could empirically investigate the presence of consciousness. If we were certain or had a reasonable belief that some types of HCOs are sentient, what kind of entity would we judge them to be? Would they have specific legal protection? Should they be attributed to a moral status? This article tries to give an initial answer to these two questions. On the one side, it seems that no special rights can be claimed for HCOs other than those relating to human biological material. On the other side, instead, a sentient HCO could aspire to having its moral status recognized. If this were the case, the law may have to adapt to this unprecedented situation.
RESUMEN
The growing use of brain imaging technology and the developing of cognitive neuroscience pose unaccustomed challenges to legal systems. Until now, the fields of Law much affected are the civil and criminal law and procedure, but the constitutional dimension of "neurolaw" cannot be easily underestimated. As the capacity to investigate and to trace brain mechanisms and functional neural activities increases, it becomes urgent the recognition and definition of the unalienable rights and fundamental values in respect of this new techno-scientific power, that must be protected and safeguard at "constitutional level" of norms such as: human dignity, personal identity, authenticity and the pursuit of individual "happiness". As the same as for the law regulating research and experimentation on human genome adopted in the past years, one may also argue if the above mentioned fundamental principles of "neurolaw" must be fixed and disciplined also at European and International level.