On the large N limit, W_\infty Strings, Star products, AdS/CFT Duality, Nonlinear Sigma Models on AdS spaces and Chern-Simons p-branes

It is shown that the large $N$ limit of SU(N) YM in $curved$ $m$-dim backgrounds can be subsumed by a higher $m+n$ dimensional gravitational theory which can be identified to an $m$-dim generally invariant gauge theory of diffs $N$, where $N$ is an $n$-dim internal space (Cho, Sho, Park, Yoon). Based on these findings, a very plausible geometrical interpretation of the $AdS/CFT$ correspondence could be given. Conformally invariant sigma models in $D=2n$ dimensions with target non-compact SO(2n,1) groups are reviewed. Despite the non-compact nature of the SO(2n,1), the classical action and Hamiltonian are positive definite. Instanton field configurations are found to correspond geometrically to conformal ``stereographic'' mappings of $R^{2n}$ into the Euclidean signature $AdS_{2n}$ spaces. The relation between Self Dual branes and Chern-Simons branes, High Dimensional Knots, follows. A detailed discussion on $W_\infty$ symmetry is given and we outline the Vasiliev procedure to construct an action involving higher spin massless fields in $AdS_4$. This $AdS_4$ spacetime higher spin theory should have a one-to-one correspondence to noncritical $W_\infty$ strings propagating on $AdS_4 \times S^7$.Comment: 43 pages, Tex fil

Renormalization Group and Probability Theory

The renormalization group has played an important role in the physics of the second half of the twentieth century both as a conceptual and a calculational tool. In particular it provided the key ideas for the construction of a qualitative and quantitative theory of the critical point in phase transitions and started a new era in statistical mechanics. Probability theory lies at the foundation of this branch of physics and the renormalization group has an interesting probabilistic interpretation as it was recognized in the middle seventies. This paper intends to provide a concise introduction to this aspect of the theory of phase transitions which clarifies the deep statistical significance of critical universality

Viabilidad de la implementación de fajinas para la estabilización de taludes en Colombia

Trabajo de InvestigaciónSe investigó las características geomorfológicas de las regiones del país, para así conocer los diferentes fenómenos de remoción en masa que se presentan y con ello se evaluó en qué zonas del territorio colombiano se puede implementar este sistema en las condiciones óptimas. A su vez se realizó un estudio de la composición y las ventajas que tiene el uso de las fajinas para el suelo. Como resultado, surgió un método que no afecta al medio ambiente.PregradoIngeniero Civi

Elusive Seed Formation via Electrical Confinement: Control of a Novel Cocrystal in Cooling Crystallization

Pharmaceutical cocrystals are multicomponent materials formed to enhance the properties of active pharmaceutical ingredients (APIs) and are commercially used to increase the number of drug candidates that successfully make it through the drug discovery pipeline. Nevertheless, the industrial production of cocrystals and other elusive solid forms remains a challenge. The main limitations are due to challenges related to the scale-up, solid-form control, and undesirable parameters needed for the preparation method. This study leverages the features of electrospray crystallization to generate elusive cocrystal forms that contain the API acetaminophen (paracetamol) and its regioisomer metacetamol. We report the formation of a new cocrystal, which is held together by van der Waals interactions, and the use of the newly electrosprayed cocrystals as seeds to tune the performance of cooling crystallization, allowing this commonly used crystallization method to produce the elusive cocrystal. The electrosprayed cocrystal displays a previously unseen sponge-like surface topology and a fourfold solubility enhancement over those found for single-component APIs. This new technology expands the accessibility to new solid forms that were previously inaccessible by other crystallization methods.</p

Defining a roadmap for harmonizing quality indicators in Laboratory Medicine: A consensus statement on behalf of the IFCC Working Group "laboratory Error and Patient Safety" and EFLM Task and Finish Group "performance specifications for the extra-analytical phases"

The improving quality of laboratory testing requires a deep understanding of the many vulnerable steps involved in the total examination process (TEP), along with the identification of a hierarchy of risks and challenges that need to be addressed. From this perspective, the Working Group \u201cLaboratory Errors and Patient Safety\u201d (WG-LEPS) of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) is focusing its activity on implementation of an efficient tool for obtaining meaningful information on the risk of errors developing throughout the TEP, and for establishing reliable information about error frequencies and their distribution. More recently, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has created the Task and Finish Group \u201cPerformance specifications for the extraanalytical phases\u201d (TFG-PSEP) for defining performance specifications for extra-analytical phases. Both the IFCC and EFLM groups are working to provide laboratories with a system to evaluate their performances and recognize the critical aspects where improvement actions are needed. A Consensus Conference was organized in Padova, Italy, in 2016 in order to bring together all the experts and interested parties to achieve a consensus for effective harmonization of quality indicators (QIs). A general agreement was achieved and the main outcomes have been the release of a new version of model of quality indicators (MQI), the approval of a criterion for establishing performance specifications and the definition of the type of information that should be provided within the report to the clinical laboratories participating to the QIs project

Defining a roadmap for harmonizing quality indicators in Laboratory Medicine: A consensus statement on behalf of the IFCC Working Group "laboratory Error and Patient Safety" and EFLM Task and Finish Group "performance specifications for the extra-analytical phases"

The improving quality of laboratory testing requires a deep understanding of the many vulnerable steps involved in the total examination process (TEP), along with the identification of a hierarchy of risks and challenges that need to be addressed. From this perspective, the Working Group “Laboratory Errors and Patient Safety” (WG-LEPS) of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) is focusing its activity on implementation of an efficient tool for obtaining meaningful information on the risk of errors developing throughout the TEP, and for establishing reliable information about error frequencies and their distribution. More recently, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has created the Task and Finish Group “Performance specifications for the extraanalytical phases” (TFG-PSEP) for defining performance specifications for extra-analytical phases. Both the IFCC and EFLM groups are working to provide laboratories with a system to evaluate their performances and recognize the critical aspects where improvement actions are needed. A Consensus Conference was organized in Padova, Italy, in 2016 in order to bring together all the experts and interested parties to achieve a consensus for effective harmonization of quality indicators (QIs). A general agreement was achieved and the main outcomes have been the release of a new version of model of quality indicators (MQI), the approval of a criterion for establishing performance specifications and the definition of the type of information that should be provided within the report to the clinical laboratories participating to the QIs project

Structural phase transition in IrTe2_2: A combined study of optical spectroscopy and band structure calculations

Ir$_{1-x}$Pt$_x$Te$_2$ is an interesting system showing competing phenomenon between structural instability and superconductivity. Due to the large atomic numbers of Ir and Te, the spin-orbital coupling is expected to be strong in the system which may lead to nonconventional superconductivity. We grew single crystal samples of this system and investigated their electronic properties. In particular, we performed optical spectroscopic measurements, in combination with density function calculations, on the undoped compound IrTe$_2$ in an effort to elucidate the origin of the structural phase transition at 280 K. The measurement revealed a dramatic reconstruction of band structure and a significant reduction of conducting carriers below the phase transition. We elaborate that the transition is not driven by the density wave type instability but caused by the crystal field effect which further splits/separates the energy levels of Te (p$_x$, p$_y$) and Te p$_z$ bands.Comment: 16 pages, 5 figure

Guía metodológica para el desarrollo de ejercicio práctico en el curso de fundamentación naval

GraficasLa guía metodológica de actividades dentro del desarrollo de una actividad académica, se constituye en una herramienta esencial que direcciona, orienta y pauta la actividad, su principio es de orden orientador y su pretensión es la comprensión y desarrollo de la actividad. El presente proyecto investigativo, busca conocer las condiciones y consideraciones esenciales que debe tener el Centro de Entrenamiento Naval de la Armada Nacional para la implementación de guía metodológica en el desarrollo de trabajo de campo o ejercicio práctico (juegos de simulación), las cuales constituyen una ayuda indispensable para la comprensión de dicha actividad y para la mejora de sus procesos académicos. El proyecto evalúa la importancia de la “guía metodológica” como herramienta esencial para la institución y su aplicación académica.The methodological activity’s guide for the academic activities is an essential tool that guidelines the activity, its principle is to guide and its pretension is to facilitate the understanding and the development of the activity. This research project, seeks to establish the essential conditions and considerations that must be take in account by the Colombian Navy Training Center, in order to implement methodological guidelines in the development of the fieldwork, practical exercises, and simulation games, which are an essential aid to the understanding of this activity and to improve their academic processes. The project evaluates the importance of "methodological guide" as an essential tool for the institution and its academic application