Flexibility of the imidazolium based ionic liquids/water system for the synthesis of siliceous 10-ring containing microporous frameworks

By using asymmetric di-substituted imidazolium molecules (1-Butyl-3-methylimidazolium (BMIM) and 1-Ethyl-3-methylimidazolium (EMIM) bromide) as the structure directing agents, in combination with simple changes in silica source or sodium/water content it is possible to prepare three pure phase microporous 10-ring siliceous zeolitic structures. The crystallizations are comparatively rapid with fully crystalline material resulting in 1–3 days at 443 K. In contrast to many recipes reported for pure silica materials, the synthesis is performed without the use of HF or without the need to alter the properties of the SDA, while significantly lower amounts of both ionic liquid and mineralizing agent are required. The results obtained indicate that effective phase control can be achieved from a primary gel composition by minor changes to either the silica source or the water/sodium content, with a strong specificity in the formation of topologies with interconnected 10-rings

GRB 180620A: Evidence for Late-time Energy Injection

The early optical emission of gamma-ray bursts (GRBs) gives an opportunity to understand the central engine and first stages of these events. About 30% of GRBs present flares whose origin is still a subject of discussion. We present optical photometry of GRB 180620A with the COATLI telescope and RATIR instrument. COATLI started to observe from the end of prompt emission at T + 39.3 s and RATIR from T + 121.4 s. We supplement the optical data with the X-ray light curve from Swift/XRT. We observe an optical flare from T + 110 s to T + 550 s, with a temporal index decay α O,decay = 1.32 ± 0.01, and Δt/t = 1.63, which we interpret as the signature of a reverse shock component. After the initial normal decay the light curves show a long plateau from T + 500 s to T + 7800 s in both X-rays and the optical before decaying again after an achromatic jet break at T + 7800 s. Fluctuations are seen during the plateau phase in the optical. Adding to the complexity of GRB afterglows, the plateau phase (typically associated with the coasting phase of the jet) is seen in this object after the "normal" decay phase (associated with the deceleration phase of the jet), and the jet break phase occurs directly after the plateau. We suggest that this sequence of events can be explained by a rapid deceleration of the jet with t d ≲ 40 s due to the high density of the environment (≈100 cm-3) followed by reactivation of the central engine, which causes the flare and powers the plateau phase

Non-Abelian discrete gauge symmetries in 4d string models

We study the realization of non-Abelian discrete gauge symmetries in 4d field theory and string theory compactifications. The underlying structure generalizes the Abelian case, and follows from the interplay between gaugings of non-Abelian isometries of the scalar manifold and field identifications making axion-like fields periodic. We present several classes of string constructions realizing non-Abelian discrete gauge symmetries. In particular, compactifications with torsion homology classes, where non-Abelianity arises microscopically from the Hanany-Witten effect, or compactifications with non-Abelian discrete isometry groups, like twisted tori. We finally focus on the more interesting case of magnetized branes in toroidal compactifications and quotients thereof (and their heterotic and intersecting duals), in which the non-Abelian discrete gauge symmetries imply powerful selection rules for Yukawa couplings of charged matter fields. In particular, in MSSM-like models they correspond to discrete flavour symmetries constraining the quark and lepton mass matrices, as we show in specific examples.Comment: 58 pages; minor typos corrected and references adde

Gestión del conocimiento en la administración pública

In Perú, the public administration does not have a solid knowledge management system, which helps to provide an efficient public service. Therefore, this research has collected a series of studies that highlight the importance of the implementation of knowledge management in both the private and public sectors, with the aim of highlighting the benefits that knowledge can generate in order to achieve optimal performance of public institutions; an effect of incorporating it as a fundamental asset that produces a positive impact on public administration; promote the construction of an institutional culture that promotes the transfer of knowledge between servers, encouraging good performance that guarantees correct and innovative decision-making, in order to provide efficient services that contribute to the integral development of society.En el Perú, la administración pública no cuenta con un sistema sólido de gestión del conocimiento, que coadyuve a brindar un servicio público eficiente. Por ello, la presente investigación ha recogido una serie de estudios que remarcan la importancia de la implementación de la gestión del conocimiento tanto en el sector privado como en el sector público, con el objetivo de resaltar los beneficios que puede generar el conocimiento en miras de conseguir un óptimo desempeño de las instituciones públicas; a efecto de incorporarlo como un activo fundamental que genere un impacto positivo en la administración pública; asimismo, fomentar la construcción de una cultura institucional que promueva la transferencia de conocimientos entre los servidores, motivando el buen desempeño que garantice la toma de decisiones correctas e innovadoras, a fin de brindar servicios eficientes que contribuyan al desarrollo integral de la sociedad

Normas que vulneran el desarrollo urbano de nuestras ciudades

This study carries out the documentary and historical analysis of several countries, compares theories and similar studies that show the consequences of urban expansion as a result of the population increase, specifically in Peru. Theoretically, the urban development process should be carried out respecting the guidelines established in the management instruments and public policies. Fact that does not occur and that is aggravated by the negative impacts on the environment and the soil, resulting in the poor quality of life of Peruvians and the lack of urban sustainability. This research analyzes the problem in relation to the number of norms and laws that are issued from the Peruvian State: legislative power, executive power, regional and local governments, among others. The organic law of each government agency grants functions that allow it to develop specific norms that, in most cases, violate the existing norms on national strategic planning that are not elaborated in a transversal and multisectoral manner, on the contrary, in many cases they are they contravene and in others they overlap. Currently, there are very few urban plans and the few that exist do not consider the technical aspects required for their effectiveness and the scarce citizen participation.Este estudio realiza el análisis documental e histórico, de varios países, compara teorías y estudios similares que muestran las consecuencias de la expansión urbana como resultado del incremento poblacional, específicamente en el Perú. Teóricamente, el proceso de desarrollo urbano debe realizarse respetando los lineamientos establecidos en los instrumentos de gestión y políticas públicas. Hecho que no ocurre y que se agrava con los impactos negativos al ambiente y al suelo, redundando en la mala calidad de vida de los peruanos y en la falta de sostenibilidad urbana. Esta investigación analiza la problemática frente a la cantidad de normas y leyes que se emiten desde el Estado peruano: poder legislativo, poder ejecutivo, gobiernos regionales y locales entre otros. La ley orgánica de cada organismo gubernamental otorga funciones que le permiten elaborar normas específicas que, en la mayoría de los casos vulneran las normas existentes sobre el planeamiento estratégico nacional que no son elaboradas de manera transversal y multisectorial, por el contrario, en muchos casos se contravienen y en otros se superponen. Actualmente, existen muy pocos planes urbanos y los pocos que existen, no consideran los aspectos técnicos requeridos para su efectividad y la escaza participación ciudadana

Interés público y constitución giratoria

Public policies must start from compliance with the constitutional charter. In its Public policies must start from compliance with the constitutional charter. In its article 65, from 1993 it establishes the consumer protection guarantee. However, in flagrant contradiction and evident discrimination, the last paragraph of Article 62, grants guarantees and assurances, only for a certain type of contract, the law-contracts. Guarantees can be established and guarantees can be granted and cannot be legislatively modified. They are constitutionally protected. This, when colliding with articles 1, 2.1, 2.2, 2.14 and 59 of the same instrument, evidently produces a conflict in the constitutional structure. Is it possible to formulate public policies, based on an unconstitutional constitution ? In Perú, yes. We have been doing it with law contracts for 28 years. We are facing a revolving constitution.Las políticas públicas, deben de partir del cumplimiento a la carta constitucional. En su artículo 65°, desde 1993 establece la garantía de Protección al consumidor. Sin embargo, en flagrante contradicción y evidente discriminación, el último párrafo del Artículo 62°, otorga garantías y seguridades, solo para un determinado tipo de contrato, los contratos-ley. Se puede establecer garantías y otorgar seguridades y no pueden ser modificados legislativamente. Están protegidos constitucionalmente. Esto, al colisionar con los artículos 1°, 2.1°, 2.2°, 2.14° y 59° del mismo instrumento, evidentemente produce un conflicto en la estructura constitucional. ¿Es posible formular políticas públicas, en base a una constitución inconstitucional? En el Perú, sí. Lo venimos haciendo con los contratos ley, desde hace 28 años. Estamos ante una constitución giratoria

Voluntariado y las diferentes motivaciones que lo impulsan

The review article sought to answer the question: What are the different motivations that drive volunteering? and the objective is to determine the main motivations that people have for volunteering. The methodology used was qualitative, under the IMRyD format, of a non-systematic review of the scientific literature in the closed access databases EbscoHost and ProQuest and open access Scielo with a total of 18 articles selected under an intentional non-probabilistic sampling that had As inclusion criteria, only articles in English, Spanish and Portuguese, that answered the research question, between the years 2018 to 2023 and with a DOI identifier. The results showed that the authors pointed out the existence of different motivators to carry out volunteering, being a multi-motivated activity and that, for the most part, they can be grouped into internal (intrinsic) motivators of the person such as faith, values, strong personal desire, overcoming problems, the feeling of success, the experiences lived, etc. and external (extrinsic) such as the influence of family, friends, the community, the environment where volunteering takes place, among others. It was concluded that there are different motivators for volunteering that should be taken into account to carry out a correct combination of strategies that consider both aspects and to be able to attract and retain more volunteers, making the various programs executed sustainable. The limitations were the closed access that other important databases have that could not be included.El artículo de revisión buscó responder la pregunta ¿Cuáles son las diferentes motivaciones que impulsan el voluntariado? y como objetivo determinar las principales motivaciones que tienen las personas para realizar voluntariado. La metodología empleada fue cualitativa, bajo el formato IMRyD, de revisión no sistemática de la literatura científica en las bases de datos de acceso cerrado EbscoHost y ProQuest y de acceso abierto Scielo con un total de 18 artículos seleccionados bajo un muestreo no probabilístico intencional que tuvo como criterios de inclusión sólo los artículos en inglés, español y portugués, que respondieran la pregunta de investigación, entre los años 2018 al 2023 y con identificador DOI. Los resultados demostraron que los autores señalaron la existencia de diferentes motivadores para realizar el voluntariado, siendo una actividad polimotivada y que, en su mayoría, se pueden agrupar en motivadores internos (intrínsecos) propios de la persona como la fe, los valores, el fuerte deseo  personal, la superación de problemas, la sensación de éxito, las experiencias vividas, etc. y externos (extrínsecos) como la influencia de la familia, amigos, la comunidad, el ambiente donde se desarrolla el voluntariado, entre otros. Se concluyó que existen diferentes motivadores para realizar el voluntariado que deberían ser tomados muy en cuenta para realizar una correcta combinación de estrategias que consideren ambos aspectos y poder captar y retener más voluntarios haciendo sostenibles los diversos programas ejecutados. Las limitaciones fueron el acceso cerrado que tienen otras bases de datos importantes que no pudieron ser incluidas

Development of efficient recirculation system for Tilapia (Oreochromis niloticus) culture using low cost materials

In the current experiment, a recirculation system was built using low cost materials that are available locally and its performance was tested. The performance evaluation procedure was carried out in an aquaculture system in greenhouse with sex-reversed male Nile tilapia (Oreochromis niloticus) production in Querétaro State, Mexico. The recirculation system had four sections (sediment collector, gravel and sand filters, biofilter and clarification) in order to eliminate the organic matter produced by the fish excretion material and uneaten food, as well as, the nitrogenous compounds undesirable in the water tanks, such as, total ammonia nitrogen (TAN). The monitored variables include: temperature, dissolved oxygen, pH, visibility, TAN, nitrites and nitrates. The obtained data were compared with previous studies to evaluate the achieved state of the system. This research clearly demonstrated that it is feasible to use the proposed configuration in aquaculture systems in areas where water source is limited. Consequently, the obtained results represent an environmental standpoint for the conservation of water use in the aquaculture industry and also constitute an important contribution to the aquaculture and farmers who receive minimal economic support.Key words: Water recirculation, aquaculture, sustainability, low cost, water use efficiency