Electrochemical Oxidation Assessment and Interaction of 2-aminoethanol and N, N-diethylethanamine Propagation in Acidic Medium

Electro�oxidation and inhibitor performance of copper specimens in 1 M hydrochloric acid solu� tion was investigated at room temperature by linear potentiodynamic polarization and gravimetric method in the presence of 2�aminoethanol (A) and N, N�diethylethanamine (D) as an inorganic inhibitor. The effect of the inhibitory concentration on the corrosion behavior of copper was studied over 288 hrs at 298°K. The inhibitory efficiency rise up to 96% for single induced and 98% for synergistic behavior. The adsorption mechanism characteristic was supported by SEM/EDX analysis and adsorption isotherm. From all indica� tion, the inhibitive efficiency of these compounds majorly depends on their molecular structure and concen� tration. The blocking effects of the surface interface were also explained on the basis of the inhibitor active action. 2�aminoethanol and N, N�diethylethanamine inhibits copper in 1 M HCl by strictly affecting both the anodic and cathodic sites. Portion of the surface covered calculated was also found to follow Langmuir adsorption isotherm

Characterization of the moisture absorption and thermal ageing behaviour of polymeric composite systems using Raman spectroscopy

Advanced polymeric materials and their respective composites are fast becoming one of the world\u27s most frequently used engineering materials. They find application in the manufacture of e.g. boat hulls, high performance motor vehicles, aircraft components and sports goods. Their high specific strength and specific stiffness give them the edge in applications where weight savings are critical, but their long-term durability is often questioned. These materials are susceptible to environmental conditions such as temperature and humidity. There is also a lack of relevant data, due to the long time-scales required for testing. In this study, the Raman technique has been used to monitor the degradation of two composite systems, namely: a rubber toughened vinylester material used in the marine industry and a high temperature bismaleimide/carbon fibre aerospace composite. Preliminary Raman studies show that the toughening rubber particles dispersed in the cured vinylester resin are leached out during hygrothermal ageing. The weight gain during ageing suggests that this leaching process occurs concurrently with the absorption of water molecules. An increase in the degree of cross-linking is observed when bismaleimide/carbon fibre composite is aged at high temperature. This cross- linking tendency decreases with increasing depth within the carbon fibre bundle

Characterisation of the moisture absorption and thermal ageing behaviour of polymeric composite systems using raman spectroscopy

Advanced polymeric materials and their respective composites are fast becoming one of the world's most frequently used engineering materials. They find application in the manufacture of e.g. boat hulls, high performance motor vehicles, aircraft components and sports goods. Their high specific strength and specific stiffness give them the edge in applications where weight savings are critical, but their long-term durability is often questioned. These materials are susceptible to environmental conditions such as temperature and humidity. There is also a lack of relevant data, due to the long time-scales required for testing. In this study, the Raman technique has been used to monitor the degradation of two composite systems, namely: a rubber toughened vinylester material used in the marine industry and a high temperature bismaleimide/carbon fibre aerospace composite. Preliminary Raman studies show that the toughening rubber particles dispersed in the cured vinylester resin are leached out during hygrothermal ageing. The weight gain during ageing suggests that this leaching process occurs concurrently with the absorption of water molecules. An increase in the degree of cross-linking is observed when bismaleimide/carbon fibre composite is aged at high temperature. This cross-linking tendency decreases with increasing depth within the carbon fibre bundle

Chapter 11: Emerging approaches in the analysis of inks on questioned documents

Questioned document is one of the oldest fields of examination reported in forensic science. Documents are used as physical (nowadays sometimes virtual) traces of human transactions, thus questioning, falsification and counterfeiting certainly have existed since their invention and routine use. This is also the case for biblical texts and art pieces for which authenticity and authorship are often disputed. While mainly handwriting comparison was reported in early works, the composition and characteristics of inks on paper were often briefly discussed (see for example the early works of Demelle or Raveneau in the XVIIe century ). Since then, many technological developments have impacted questioned document examination, both with regard to the ink and paper production, as well as to the writing instruments or printing techniques. Nowadays, further progress have changed the world of (questioned) documents, through the introduction of virtual documents using electronic signatures and security documents such as passports using mixed physical and digital biometric data. Thus, the document examiner' expertise has to quickly evolve and adapt to such developments, sometimes necessitating the combination of skills from different disciplines not always co-existing in forensic laboratories (such as chemistry, physics, statistics, engineering, material science, computer science). After a brief overview of the historical development in both ink formulation and analysis, this chapter will investigate the relevance of rapidly evolving technologies for application to the examination of questioned documents in a forensic perspective