Le Corbusier,Teilhard de Chardin and The Planetisation of Mankind'

The modern world has made all things interrelated, the relations are continuous and contiguous around the globe, affected by nuances and diversity... The question is man and his environment, an event of local as well as of global order. 1 Le Corbusier was very interested in the ideas of the Jesuit priest and distinguished palaeontologist Pere Pierre Teilhard de Chardin. 'Do you know this man and his research (Palaeontology, the human condition, the future)?' wrote the architect to his friend and collaborator Andreas Speiser on 22 December, 1954.2 In this letter (Fig. 1) he relates that he spent the whole journey back from India reading the priest's works. 'I was very favourably impressed by him' he wrote, 'I must get in touch with him before long.' Le Corbusier includes in the letter a list of papers by Teilhard, which he must have believed to be of particular interest. The 'etc' at the end of this list is of interest, indicating the extent of the architect's reading of this profoundly religious man. Le Corbusier asterisked the first essay, linking it with the word ' avenir ' or future and also the word ' definitives ,' definitive answers, a word which he then crossed out with one line, leaving it clearly legible. It is as though he believed that Teilhard had the answers that he was so desperately looking for, but years of disappointment, secrecy and disillusionment had made him wary. Being first on the list, the essay La Planetisation Humaine , 'The Planetisation of Mankind' is probably the most important in terms of Le Corbusier's reading of Teilhard.3 In this paper I will focus on the essay in an attempt to deduce just why Le Corbusier was so impressed by the works of this radical priest. In doing so, I hope to shed some light on Le Corbusier's spiritual agenda for architecture, an aspect of his work which still remains remarkably obscure. In particular I will focus on the concept of community expressed in the Unite block in Marseilles (1952). It should be mentioned that Le Corbusier does make other references to Teilhard, for example in an interesting stream of consciousness in one of his sketchbooks of 1960.4 Incidents such as this indicate that the priest's ideas were a continuing source of inspiration for the architect.     

Coarse-Grained and Atomistic MD Simulations of RNA and DNA Folding

Although the main features of the protein folding problem are coming into clearer focus, the microscopic viewpoint of nucleic acid folding mechanisms is only just beginning to be addressed. Experiments, theory, and simulations are pointing to complex thermodynamic and kinetic mechanisms. As is the case for proteins, molecular dynamics (MD) simulations continue to be indispensable tools for providing a molecular basis for nucleic acid folding mechanisms. In this review, we provide an overview of biomolecular folding mechanisms focusing on nucleic acids. We outline the important interactions that are likely to be the main determinants of nucleic acid folding energy landscapes. We discuss recent MD simulation studies of empirical force field and Go-type MD simulations of RNA and DNA folding mechanisms to outline recent successes and the theoretical and computational challenges that lie ahead.     

Investigation of cure kinetics in epoxy/multiwalled carbon nanotube nanocomposites

With the increased interest in thermoset resin nanocomposites, it is important to understand the effects of the material on nanoscale characteristics. In this study, a curing reaction of an epoxy resin, which contained 0.25, 0.50, or 1.00 wt % of multiwalled carbon nanotubes (MWCNTs), at different heating rates was monitored by differential scanning calorimetry; cure kinetics were also evaluated to establish a relationship between crosslinking (network formation) and mechanical properties. MWCNT concentrations above 0.25 wt % favored crosslinking formation and decreased the activation energy (E_a) in the curing reaction. Examination of the kinetic mechanism suggests that the MWCNT locally restricted the spatial volume and favored the formation of nodular morphology in the resin, especially for high MWCNT concentrations. The MWCNT exhibited some entanglement in the matrix, which hindered a more pronounced effect on the mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39857.     

Polyamide hydrolysis accelerated by small weak organic acids

It is well known that acidity, pH, of a solution accelerates the hydrolysis of soluble amides. Here we describe the unexpected result that weak small organic acids at low concentrations hydrolyze a polyamide at rates approximately twice that of a water HCl solution of the same pH. The effect of three small organic acids in dilute solutions, acetic, propanoic, and butanoic was studied. It is observed that the effect on the hydrolysis rate increases as the organic acid gets weaker. Butanoic, the weakest acid, has the strongest effect on increasing the hydrolysis rate. Measurements on the concentration of these acids in the polyamide reveal that there is a selective desire for these weak organic acids to diffuse into the polyamide. The concentration of these acids in the polyamide is found to be several multiples of the concentration in the water environment. And the acid concentration is highest for butanoic. The hydrolysis rate is shown to be governed by solubility, not pH of the water environment. The longer hydrocarbon tail on the carboxylic group increases its compatibility with the polyamide's monomer structure. Results are reported on the hydrolysis of polyamide-11 polymerized from aminoundecanoic acid, both neat and a commercial plasticized composition, placed in water at 100 °C and 120 °C under anaerobic conditions in high pressure glass tubes.     

Understanding of the annealing temperature impact on ion implanted bifacial n‐type solar cells to reach 20.3% efficiency

Ion implantation has the advantage of being a unidirectional doping technique. Unlike gaseous diffusion, this characteristic highlights strong possibilities to simplify solar cell process flows. The use of ion implantation doping for n‐type PERT bifacial solar cells is a promising process, but mainly if it goes with a unique co‐annealing step to activate both dopants and to grow a SiO₂ passivation layer. To develop this process and our SONIA cells, we studied the impact of the annealing temperature and that of the passivation layers on the electrical quality of the implanted B‐emitter and P‐BSF. A high annealing temperature (above 1000 °C) was necessary to fully activate the boron atoms and to anneal the implantation damages. Low J_0BSF (BSF contribution to the saturation current density) of 180 fA/cm² was reached at this high temperature with the best SiO₂ passivation layer. An average efficiency of 19.7% was reached using this simplified process flow (“co‐anneal process”) on large area (239 cm²) Cz solar cells. The efficiency was limited by a low FF, probably due to contaminations by metallization pastes. Improved performances were achieved in the case of a “separated anneals” process where the P‐BSF is activated at a lower temperature range. An average efficiency of 20.2% was obtained in this case, with a 20.3% certified cell. Copyright © 2014 John Wiley & Sons, Ltd.     

Char Formation in Flame‐Retarded Fibre–Intumescent Combinations. Part V. Exploring Different Fibre/Intumescent Combinations

Previous research work in our laboratory has indicated that the efficiency of certain flame‐retardant fibres can be further enhanced if certain interactive intumescents are dispersed on their surfaces. In our previously reported work we have successfully observed interactions between certain commercially available flame‐retardant cellulosic and regenerated cellulose (viscose) fibres and two melamine and phosphoric acid‐based intumescent systems. In the present work we have explored the use of other intumescent systems—melamine cyanurate, melamine borate, melamine oxalate, melamine pyrophosphate and an inorganic silicate‐based intumescent, Cylatherm. Two non‐cellulosic fibres—the novoloid (Kynol) and melamine‐formaldehyde (Basofil) were also explored in combination with different intumescent systems. These systems were studied by thermal analytical techniques to observe any possible interaction between FR fibre and intumescent components. Of these intumescents, only melamine borate and melamine pyrophosphate showed interactions with flame retardant cellulosic fibres and both Kynol and Basofil indicated char interactive tendencies with some of the phosphorus‐containing intumescents. Copyright © 2002 John Wiley & Sons, Ltd.     

Influence of Aging Parameters on the Tensile Properties and Quality Index of Al-9?Pct Si-1.8?Pct Cu-0.5?Pct Mg 354-Type Casting Alloys

The current study was carried out with a view to investigating the influence of age-hardening parameters, aging temperature and time, on the tensile properties and quality indices of a high-strength Al-9 pct Si casting alloy, namely, 354-Al-9 pct Si-1.8 pct Cu-0.5 pct Mg. Quality charts were used as an evaluation tool for selecting the optimum conditions to be applied, in practice, in order to develop high strength and optimum quality in 354 casting alloy. Aging at a low temperature of 428 K (155 °C) was observed to produce the greatest strength and optimum quality in the 354-type castings compared to aging at higher temperatures. The peak strength observed for 354 alloy may be attained after shorter aging times on the condition that the aging temperature is increased. The aging times required for reaching peak strength in 354 alloys are 72 hours, 40 hours, 8 hours, 1 hour, and 15 minutes at aging temperatures of 428 K, 443 K, 468 K, 493 K, and 518 K (155 °C, 170 °C, 195 °C, 220 °C, and 245 °C), respectively. Aging treatment at higher temperatures is accompanied by a reduction in the tensile properties and quality index values of the castings; however, it also introduces the possibility of a significant economical strategy for minimizing the time and the cost of this same treatment. Aging treatment at a lower temperature of 428 K (155 °C) produces fine and dense precipitates displaying smaller interparticle spacing, while at higher aging temperatures, such as 518 K (245 °C), the precipitates are coarser in size, less dense, and more widely dispersed. The quality charts developed in the course of the current research facilitate the interpretation and evaluation of the tensile properties of the 354 alloy. Such charts provide a logical evaluation tool, from the metallurgical point of view, for an accurate prediction of the influence of aging parameters studied on the properties of the alloys. Depending on the required level of tensile properties and based on the quality charts developed, it is possible to make a rigorous selection as to the most suitable aging parameters to be applied to the 354 alloy so as to obtain the best possible cost-effective compromise between alloy strength and quality.