Examination of the Plenum and Deposition Coupon of the Phebus FPT4 Test by Scanning Electron Microscopy and Photoemission Spectroscopy

Samples of the thoria thermal shroud from the plenum and a deposition coupon from a filter cartridge of the FPT4 test of the Phebus PF project were examined using electron-optical analysis and by photoemission spectroscopy (XPS). The aim was to determine the nature of the fission product deposits formed under conditions of severe nuclear accidents. The plenum had considerable deposits containing Zr, Mo, Ba, Cs, and locally U was found by energy dispersive analysis. The XPS analysis showed that the deposits are mostly in oxidic form, but no U was found in the deposit, although chemical analysis showed considerable amounts present. A possible explanation is that there is layering of the deposit and that U is not released in the early stages. The coupon had very sparse deposits with only occasional U and Re particles; however large, pure Cs particles were observed on the surface that may have come from the filter deposits upstream. Thus an estimate of the deposition behaviour of fission product and fuel dispersed under extreme nuclear accident conditions is built up.     

Intriguing formal [2+3] cycloaddition promoted by a hypervalent iodine reagent

Treatment of various substituted phenols in the presence of iodobenzene diacetate, perfluorinated alcohols and furan, allylsilanes or cyclic enol ethers promotes an oxidative annulation process in moderate to useful yields. In only one step, this method produces different heterocyclic rings such as dihydrofuranobenzofurans, tetrahydrofuranobenzofurans, tetrahydropyranofurans, and dihydrobenzofurans.     

A novel amphiphilic pH-sensitive hydrogel based on pullulan

Novel polyelectrolyte and amphiphilic hydrogels based on pullulan have been prepared using 1-ethyl-3-[3-(dimethylamino)-propyl]carbodiimide hydrochloride and N-hydroxysuccinimide. The cross-linking reaction is fast and lead to zero length ester cross-links by the reaction of a carboxylate group with an alcohol function of the polysaccharide. The charge density and the hydrophobic rate of the precursor carboxymethylpullulan (CMP) are controlled during the carboxymethylation of pullulan and the grafting reaction of octyl chains on CMP, respectively. The grafting degree influences the conformation of the hydrophobically modified CMP (HMCMP) in solution and leads to the formation of hydrophobic clusters firstly in the HMCMP solutions and further in the HMCMP hydrogels. The swelling measurements of HMCMP hydrogels at different salt concentrations (0–0.2 M NaCl) and different pH (3–11) shows the ionic strength and pH sensitivity of the gels. The loading of a hydrophobic probe molecule can be controlled by the grafting degree of HMCMP hydrogels.     

Adaptation as a Morphing Process: A Methodology for the Design and Evaluation of Adaptive Organizational Structures

Changes in objectives, in resources, or in the environment may necessitate the adaptation of an organization from one form to another. However, in many cases, the organizations need to continue functioning while adaptation takes place, i.e., it is not possible to stop the organizational activity in order to reorganize, and then start again. In this case, adaptation can be expressed as a morphing process in which the organization transitions from one form with its attendant task allocation to a different one through a series of incremental steps that preserve overall functionality and performance. Coordination between organization members during adaptation is critical. A computational model for this type of organizational adaptation at the operational level is presented. The model is implemented using the Colored Petri Net formulation of discrete event dynamical systems. A design methodology that utilizes this model is outlined and a simple example is used to illustrate the approach.     

Chevalley Cohomology for linear graphs

The space of linear polyvector fields on is a Lie subalgebra of the (graded) Lie algebra , equipped with the Schouten bracket. In this paper, we compute the cohomology of this subalgebra for the adjoint representation in , restricting ourselves to the case of cochains defined with purely aerial Kontsevich’s graphs, as in Pac. J. Math. 218(2):201–239, 2005. We find a result which is very similar to the cohomology for the vector case Pac. J. Math. 229(2):257–292, 2007. This work was supported by the CMCU contract 06 S 1502. W. Aloulou and R. Chatbouri thank the Université de Bourgogne and D. Arnal the Faculté des Sciences de Monastir for their kind hospitalities during their stay.     

Basis set exchange: a community database for computational sciences

Basis sets are some of the most important input data for computational models in the chemistry, materials, biology, and other science domains that utilize computational quantum mechanics methods. Providing a shared, Web-accessible environment where researchers can not only download basis sets in their required format but browse the data, contribute new basis sets, and ultimately curate and manage the data as a community will facilitate growth of this resource and encourage sharing both data and knowledge. We describe the Basis Set Exchange (BSE), a Web portal that provides advanced browsing and download capabilities, facilities for contributing basis set data, and an environment that incorporates tools to foster development and interaction of communities. The BSE leverages and enables continued development of the basis set library originally assembled at the Environmental Molecular Sciences Laboratory.     

Short synthesis of the C16-C28 polyketide fragment of apoptolidin A aglycone

Starting from (E,E)-1-[(1R)-(phenylethyl)oxy]-2-methylpenta-1,3-diene and triethylsilyl enol ether of butanone rapid access to Koert's advanced C10-C28 polyketide fragment of apoptolidin A is now possible.