Functionalized N‑Heterocyclic Carbene Nonspectator Ligands upon Internal Alkyne Activation Reactions

When studying the activation of 3-arylpropiolates by [TpRu(picolyl-RI)Cl]/NaBArF 4 (picolyl-MeI = 3-methyl-1-(2- picolyl)imidazol-2-ylidene (1); picolyl-MeBI = 3-methyl-1-(2- picolyl)benzoimidazol-2-ylidene (2)) a migratory insertion of the NHC into a ruthenium−carbon bond and an unprecedented C−N bond activation of the chelating picolyl-NHC ligand take place to give the new ruthenium metallacycles [TpRu(κ3-C,N,N′- =C(Ph) = C(CH2Py)(CO2Me)(MeI)][BArF 4] 3a and 4a and [TpRu(κ3-C,N,N′-=C(4-CF3Ph) = C(CH2Py)(CO2Me)(MeI)]- [BArF 4] 3b and 4b. X-ray crystal structures of 3a and 3b are reported, and a mechanistic pathway is proposed. In contrast, activation of internal alkynones by a mixture of [TpRu(picolyl-MeI)Cl] complex (1) and NaBArF 4 led to isolation and characterization of the corresponding disubstituted vinylidene complexes. Also, structures of [TpRu(picolyl-MeI)(= CC(COR)(Ph)][BArF 4] (R = Me (6a); Ph (6b)) are reported

Using Probabilistic Safety Analysis (PSA) to Optimize Operation Schedules

This is the first report of a work on time dependent probabilities initiated as a cooperation between the International Atomic Energy Agency (IAEA) and IIASA in 1990. The treatment of the underlying mathematical model is rather theoretical, but the intent has been to cover a broad range of applications. Originally the formulation was initiated by the problem of optimization of test intervals at nuclear power plants. There have however been also other applications proposed to be treated within the proposed modelling framework. One specific problem is the selection of the most suitable time instant for a major repair or retrofitting at a plant. The time horizon of the model can be selected either short stretching only over a few weeks or very long to encompass the complete life time of a depository of spent nuclear fuel. The advantage with the problem formulation is that it enables the inclusion also of monetary considerations connected to risks and the actions for decreasing them. The intent in formulating the model is that it will be used for a computerized optimization of selected decision variables

Responsabilidad penal de los médicos

Fil: Valerga Aráoz, Jorge A. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Penal II. Buenos Aires, ArgentinaTemas de Derecho Penal I

Impact of Chemical Post-Processing in Fused Deposition Modelling (FDM) on Polylactic Acid (PLA) Surface Quality and Structure

The application of techniques to improve the surface finish of pieces obtained by fused deposition modelling, as well as other functional aspects, is of great interest nowadays. Polylactic acid, a biodegradable material, has been considered a possible substitute for petroleum-based polymers. In this work, different chemical post-processing methods are applied to polylactic acid pieces obtained by fused deposition modelling and some characteristics are studied. Structural, thermal, and crystallinity property changes are analyzed according to the treatments applied. This can prevent degradation, eliminate the glass transition phase of the material, and thereby increase the thermal resistance by about 50 C. An improvement in the roughness of the pieces of up to 97% was also found

A triclinic polymorph of (E)-2-(2-nitro­ethen­yl)furan

The title compound, C6H5NO3, crystallizes in the triclinic system with six independent mol­ecules in the asymmetric unit. In a previous study, the structure of the title compound was determined in the monoclinic P21/n space group at 100 K [Valerga et al. (2009 ▶). Acta Cryst. E65, o1979]. All six independent mol­ecules display an E configuration about the C=C double bond, with the dihedral angles between the planes of the furan rings and the nitro­alkenyl groups ranging from 0.61 (7) to 5.03 (7)°. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen-bonding inter­actions

Influence of PLA Filament Conditions on Characteristics of FDM Parts

Additive manufacturing technologies play an important role in Industry 4.0. One of the most prevalent processes is fused deposition modelling (FDM) due to its versatility and low cost. However, there is still a lack of standardization of materials and procedures within this technology. This work aims to study the relationship of certain operating parameters and the conditions of poly(lactic acid) (PLA) polymer with the results of the manufactured parts in dimensional terms, surface quality, and mechanical strength. In this way, the impact of some material characteristics is analyzed, such as the pigmentation of the material and the environmental humidity where it has been stored. The manufacturing parameter that relates to these properties has been the extrusion temperature since it is the most influential in this technology. The results are quite affected especially by humidity, being a parameter little studied in the literature.This research was funded by the Spanish Government via the Ministry of Economy, Industry and Competitiveness, the European Union (FEDER/FSE), and the Andalusian Government (PAIDI), project MINERVA

Sustentación de caso: propuesta de un plan estratégico del ingreso al mercado peruano de una empresa del sector fast fashion

El trabajo pretende analizar a fondo a la empresa Fast Retailing, a su competencia, y al sector de retail en el Perú; para poder concluir con conclusiones concretas y recomendaciones con respecto al ingreso de “Uniqlo” (marca estrella de Fast Retailing) en el mercado peruano

Optimized design and manufacturing of a motorcycle fairing spider

In the racing world, weight is one of the key factors when developing a vehicle. Therefore, the aim is to reduce it as much as possible to achieve a good power/weight ratio that can be translated into increased speed, manoeuvrability, or reduced fuel consumption. For this reason, the trend is to redesign existing parts to obtain more optimised and lighter ones using new materials and complex structures that are often manufactured using 3D printing. In this manuscript, a spider or support for the fairing of a racing motorbike was designed, making use of topological optimisation techniques by means of Computer-Aided Design and using additive manufacturing. Specifically, PLA was used as an eco-friendly material to replace the conventional welded metal used in these areas of a motorbike. Theoretical and experimental tests were carried out to confirm the viability of the piece. With the analysis of the topological optimisation, it was possible to manufacture a sustainable, low weight and low cost part, which has never been manufactured before with a polymeric material

Ruthenium(II) Picolyl-NHC Complexes: Synthesis, Characterization, and Catalytic Activity in Amine N‑alkylation and Transfer Hydrogenation Reactions

Ruthenium(II) p-cymene complexes with picolylfunctionalized N-heterocyclic carbenes [(η6-p-cymene)Ru(L)(Cl)]- [PF6] (L = 3-methyl-1-(2-picolyl)imidazol-2-ylidene (1a), 3- isopropyl-1-(2-picolyl)imidazol-2-ylidene (1b), 3,4,5-trimethyl- 1-(2-picolyl)imidazol-2-ylidene (1c), 3-mesityl-1-(2-picolyl)- imidazol-2-ylidene (1d), 3-methyl-1-(2-picolyl)benzoimidazol- 2-ylidene (1e), 3-methyl-1-(2-picolyl)-4,5-dichloroimidazol-2- ylidene (1f), 3-phenyl-1-(2-picolyl)imidazol-2-ylidene (1g)) have been synthesized and characterized. Compounds 1a−g were recrystallized, and X-ray crystal structures are reported for 1a,f. Furthermore, compounds 1a−f show catalytic activity in transfer hydrogenation of ketones and N-alkylation of amines. Notably, complexes 1a,c,f were found to be very efficient and versatile catalysts toward transfer hydrogenation of a wide range of ketones and imines in addition to N-alkylation of several amines