237 research outputs found
Waste glass as a precursor in alkaline activation: Chemical process and hydration products
This paper discusses the results of alkali-activating waste glass in pursuit of a new type of alkali activated materials (AAMs). Waste glass pastes were prepared with different alkaline activators (NaOH, NaOH/ Na2CO3, sodium silicate hydrate and KOH) with different concentrations and cured for 20 h at 85 C and at 99% or 6.5% relative humidity to assess the effect of these variables on paste mechanical strength and microstructure. Compressive strength performance was better at the higher alkaline concentrations and when the pastes were cured at low relative humidity (6.5%), which induced low porosity (MIP) and high specific surface (BET). Irrespective of the type of activator or curing process, the main reaction product was a Si-high, Al-low gel. As a raw material for alkaline cement manufacture, waste glass delivered compact, high-strength cementitious skeletons.This research was funded by the Ministry of Economy and Competitiveness under projects BIA2010-15516 and BIA2013-47876-C2-1-P and the Spanish National Research Council under project PIE201460E06. The authors wish to thank Eduardo Torroja Institute for Construction Science technicians Alfredo Gil, Francisco Morales and Patricia Rivilla for their assistance with the laboratory trials
Waste glass in the geopolymer preparation. Mechanical and microstructural characterisation
Alkali activated materials have a variety of niche applications (other than as a large-scale civil infrastructure material) in which alkali-activated binders and concretes have shown potential for commercial-scale development. The majority of these applications have not yet seen large-scale alkali activated materials utilisation, moreover, there have been at least pilot-scale or demonstration projects in different areas and each provides scope for future development and potentially profitable advances in science and technology. This paper explores the feasibility of generating geopolymers from fly ash using waste glass as an alkaline activator (waterglass family). The mechanical properties of the cementitious geopolymers obtained by alkali-activating fly ash with three solutions: sodium hydroxide 8 M, sodium hydroxide 10 M þ 15% waterglass and sodium hydroxide 10 M þ 15 g of waste glass were determined, along with their microstructural characteristics using Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, Mercury Intrusion Porosimetry, Mass Nuclear Magnetic Resonance, Scanning Electron Microscopy and Back Scattering Electron Microscopy. The main reaction product in all the systems studied was the alkaline aluminosilicate hydrate gel to which geopolymers owe their mechanical properties. The gel formed when the system contained an extra source of silicon was shown to prompt compositional differences, while the degree of reaction, microstructure and Si/Al and Na/Al ratios were very similar in the former two systems. Waste glass proved to be an effective alkaline activator in geopolymer preparation.The present research was funded by the Spanish Ministry of Economy and Competitiveness under project BIA2010-15516.Publicad
Use of glass waste as an activator in the preparation of alkali-activated slag. Mechanical strength and paste characterisation
The alkaline activation of aluminosilicates yields alkaline cements, eco-efficient alternatives to ordinary Portland cements. Alkaline cements and concretes exhibit highest strength and longest durability when activated with a solution of alkaline silicate hydrates (waterglass). To obtain these alkaline silicates, however, an aqueous solution of the proper proportion of carbonate and silica salts must be heated to temperatures of around 1300 °C. The present paper explores the feasibility of using urban and industrial glass waste as a potential alkaline activator for blast furnace slag (AAS). AAS pastes were prepared with three activators: waterglass, a NaOH/Na2CO3 mix and the solutions resulting from dissolving glass waste in NaOH/Na2CO3. Mechanical, mineralogical (XRD, FTIR) and microstructural (porosimetry, NMR and SEM/EDX) trials were conducted to characterise the pastes obtained. The findings proved the feasibility of using glass waste to alkali activate slag. Treating glass waste with NaOH/Na2CO3 (pH = 13.6) favours the partial dissolution of the Si in the glass into its most reactive monomeric form. The solutions resulting from the treatment of glass waste act as alkaline activators, partially dissolving vitreous blast furnace slag. The composition and microstructure of the reaction products identified in the two types of paste were similar. Strength and microstructural development in the pastes activated with glass waste were also comparable to the parameters observed in AAS pastes prepared with conventional activators.The present research was funded by the Ministry of Economy and Competitiveness under project BIA2010-1551
Branching-time logic ECTL# and its tree-style one-pass tableau: Extending fairness expressibility of ECTL+
Temporal logic has become essential for various areas in computer science, most notably for the specification and verification of hardware and software systems. For the specification purposes rich temporal languages are required that, in particular, can express fairness constraints. For linear-time logics which deal with fairness in the linear-time setting, one-pass and two-pass tableau methods have been developed. In the repository of the CTL-type branching-time setting, the well-known logics ECTL and ECTL+ were developed to explicitly deal with fairness. However, due to the syntactical restrictions, these logics can only express restricted versions of fairness. The logic CTL*, often considered as ‘the full branching-time logic’ overcomes these restrictions on expressing fairness. However, CTL* is extremely challenging for the application of verification techniques, and the tableau technique, in particular. For example, there is no one-pass tableau construction for CTL*, while one-pass tableau has an additional benefit enabling the formulation of dual sequent calculi that are often treated as more ‘natural’ being more friendly for human understanding.
These two considerations lead to the following problem - are there logics that have richer expressiveness than ECTL+, allowing the formulation of a new range of fairness constraints with ‘until’ operator, yet ‘simpler’ than CTL?, and for which a one-pass tableau can be developed? Here we give a positive answer to this question, introducing a sub-logic of CTL* called ECTL#, its tree-style one-pass tableau, and an algorithm for obtaining a systematic tableau, for any given admissible branching-time formulae. We prove the termination, soundness and completeness of the method. As tree-shaped one-pass tableaux are well suited for the automation and are amenable for the implementation and for the formulation of sequent calculi. Our results also open a prospect of relevant developments of the automation and implementation of the tableau method for ECTL#, and of a dual sequent calculi.Authors have been partially supported by Spanish Project TIN2017-86727-C2-2-R, and by the University of the Basque Country under Project LoRea GIU18/182
Some general incompleteness results for partial correctness logics
AbstractIt is known that incompleteness of Hoare's logic relative to certain data type specifications can occur due to the ability of partial correctness assertions to code unsolvable problems; cf. Andréka, Németi, and Sain (1979, Lecture Notes in Computer Science Vol. 74, pp. 208–218, Springer-Verlag, New York/Berlin) and Bergstra and Tucker (1982, Theoret. Comput. Sci. 17, 303–315). We improve what we think are the main known theorems of this kind, showing that they depend only on very weak assumptions on the data type specification (ensuring the ability to simulate arbitrarily long finite initial segments of the natural numbers with successor), and pointing out that the recursion theoretic strength of the obtained results can be increased
Significado da experiência materna ao redor do apoio durante seu processo de amamentação
Introduction: It has been described that there are experiences in people's lives that have the capacity to modulate the nervous system, which directly influences human development. Timely intervention in early childhood has the potential to have a positive impact on their development. In this logic, breastfeeding takes on special importance, since it increases the probability of survival, provides adequate nutrition and stimulation, favors a safe environment, and is an immense contribution to the strengthening of social ties, among other benefits. The support the mother receives during the process is fundamental for successful breastfeeding. Objective: To unveil the meaning of the maternal experience on support during the breastfeeding process. Methodology: A phenomenological design study in which an analysis was carried out with secondary data, according to Edmund Husserl's perspective. To ensure the methodological rigor of this research, the criteria of Guba and Lincoln were applied. The ethical aspects of the research were approached from Ezekiel Emanuel's seven ethical requirements. Findings: The meaning of the maternal experience of support during the breastfeeding process was unveiled in four comprehensive categories: maternal experience of breastfeeding, experience of support from health professionals, experience of support from partners, and experience of support from other family members. Conclusion: The three sources of support identified nurture and modulate the breastfeeding experience in a complementary manner, so that the indivisibility of the influences exerted by them is a constitutive characteristic for the support to be perceived by the mothers as comprehensive and supportive.Introducción: Se ha descrito la existencia de experiencias de la vida de las personas que tienen la capacidad de modular el sistema nervioso, lo que influye directamente en el desarrollo humano. Intervenir oportunamente en la primera infancia tiene el potencial de impactar positivamente en su desarrollo. En esta lógica, la lactancia materna cobra especial protagonismo, ya que aumenta la probabilidad de sobrevivir, brinda una nutrición y estimulación adecuada, favorece un entorno seguro, además de ser un inmenso aporte en el fortalecimiento de los lazos sociales, entre otros beneficios. El apoyo que reciba la madre durante el proceso es fundamental para lograr un amamantamiento exitoso. Objetivo: Develar el significado de la experiencia materna en torno al apoyo en el proceso de amamantamiento. Metodología: Estudio de diseño fenomenológico en el cual se realizó un análisis con datos secundarios, según la perspectiva de Edmund Husserl. Para asegurar el rigor metodológico de esta investigación se aplicaron los criterios de Guba y Lincoln. Los aspectos éticos de la investigación fueron abordados desde los siete requisitos éticos de Ezekiel Emanuel. Resultados: El significado de la experiencia materna en torno al apoyo en el proceso de amamantamiento se develó en cuatro categorías comprensivas: la experiencia materna de amamantamiento, experiencia de apoyo de los profesionales de la salud, experiencia de apoyo de la pareja y experiencia de apoyo de otros familiares. Conclusión: Las tres fuentes de apoyo identificadas nutren y modulan la experiencia de amamantamiento de manera complementaria, por lo que la indivisibilidad de las influencias ejercidas por ellas es una característica constitutiva para que el apoyo sea percibido por las madres como comprensivo y contenedor.Introdução: Descreveu-se a existência de experiências de vida de pessoas que têm a capacidade de moldar o sistema nervoso, o que influencia diretamente no desenvolvimento humano. Intervir oportunamente na primeira infância tem o potencial de impactar positivamente no seu desenvolvimento. Seguindo esta lógica, o aleitamento materno ganha um protagonismo especial, já que aumenta a probabilidade de sobrevivência, oferece nutrição e estimulacão adequadas, favorece um ambiente seguro, além de ser uma imensa contribuição no fortalecimento de laços sociais, entre outros benefícios. O apoio que a mãe recebe durante o processo é fundamental para conseguir uma amamentação de sucesso. Objetivo: Revelar o significado da experiência materna ao redor do apoio no processo do aleitamento materno. Metodologia: Estudo do desenho fenomenológico, para o qual se realizou a análise com dados secundários, conforme a perspectiva de Edmund Husserl. Para garantir o rigor metodológico desta investigação foram aplicados os critérios de Guba e Lincoln. Os aspectos éticos da investigação foram abordados desde os sete requisitos éticos de Ezekiel Emanuel. Resultados: O significado da experiência materna ao redor do apoio no processo da amamentação foi dividido em quatro categorias compreensivas: a experiência materna do aleitamento, a experiência do apoio dos profissionais da saúde, a experiência do apoio do parceiro e a experiência do apoio de outros familiares. Conclusão: As três fontes de apoio identificadas nutrem e moldam a experiência do aleitamento de forma complementária. Por tanto, a indivisibilidade das influências que cada um destes atores exercem é uma característica constitutiva para que o apoio seja percebido pelas mães como compreensivo e acolhedor
Síndrome de Burnout y calidad de vida en el trabajo de administrativos del Hospital Nacional Guillermo Almenara La Victoria-2018
La presente investigación fue titulada el “Síndrome de Burnout y calidad de vida en el trabajo de administrativos del Hospital Nacional Guillermo Almenara La Victoria 2018” el objetivo fue identificar la relación del estudio del síndrome de Burnout y la calidad de vida en el trabajo, se mantuvieron diversas teorías de investigación, se enfocó en dos pilares fundamentales, el primero clínico y psicosocial.
El enfoque de la investigación fue cuantitativo, cuyo método fue hipotético deductivo, de tipo básica, de nivel de investigación correlacional, diseño no experimental y de corte transversal. La población estuvo conformada por 104 trabajadores del Hospital Nacional Guillermo Almenara; se utilizó el Alfa de Cronbach para la confiabilidad y para la validez el juicio de expertos para determinar la validación de instrumentos, la recolección de datos se obtuvo a través de la encuesta dirigida a través de dos cuestionarios. Posteriormente se procesó la información con el programa estadístico SPSS y se procedió a elaborar la discusión, conclusión y recomendaciones.
Se concluye en que existe una relación inversa, negativa, moderada y significativa entre el síndrome de burnout y la calidad de vida en el trabajo (-0.457) con un p valor=0.000<0.05, en los trabajadores administrativos del Hospital Nacional Guillermo Almenara, La Victoria-2018
Afectación de la intimidad en el delito de difusión de imágenes, materiales audiovisuales o audios con contenido sexual – Distrito Sullana
La investigación titulada “Afectación de la intimidad en el delito de
difusión de imágenes, materiales audiovisuales o audios con contenido sexual –
Distrito Sullana”; es un trabajo de tipo descriptivo; cuyo diseño de investigación
es no experimental. El problema de investigación se plasma con la interrogante
¿Existe una afectación del derecho a la intimidad en el delito de difusión de
imágenes, materiales audiovisuales y audios con contenido sexual? La hipótesis
planteada es que si existe una correcta regulación del delito de difusión de
imágenes, materiales audiovisuales o audios de contenido sexual, se evitaría la
afectación de la intimidad. Este delito reprime las intromisiones que se generan
debido a la tecnología tutelando el bien jurídico de la intimidad; sin embargo, este
precepto legal es muy limitado en el reproche penal y en sus circunstancias,
provocando impunidad en conductas merecedoras de una pena.
La presente investigación tiene como objetivo general determinar si existe
una afectación de la intimidad en el delito de difusión de imágenes, materiales
audiovisuales o audios con contenido sexual. Para la recolección de los datos, se
utilizó el instrumento consistente en un cuestionario, realizado a los Fiscales
Penales del Distrito de Sullana, obteniéndose como resultado más relevante que
existe un incorrecta redacción del delito de difusión de imágenes, materiales
audiovisuales o audios con contenido sexual, en lo concerniente a la protección
del bien jurídico a la intimidad, propio del vacío legal existente.
Se concluyó que existe una afectación de la intimidad en la regulación del
delito de difusión de imágenes, materiales audiovisuales o audios con contenido
sexual; debido a que no se reprocha penalmente al sujeto que obtiene de manera
ilícita el contenido sexual; generándose que el hecho concurra en atípico y como
consecuencia se vulnere el derecho a la intimidad
Condiciones de salud del paciente que prolonga su estancia hospitalaria en un Hospital del Lima, 2020
El objetivo de la investigación fue determinar la influencia de las condiciones de salud
del paciente en la prolongación de la estancia hospitalaria en un hospital de Lima,
2020. La metodología fue de tipo cuantitativo, nivel analítico y diseño no experimental.
Ante las restricciones sanitarias en el establecimiento de salud la muestra fue de 90
unidades de análisis. El instrumento empleado fue el National Early Warning Score 2
(NEWS 2). Los resultados del estudio mostraron: El 98,7% de los pacientes que se
encontraron hospitalizados mayor o igual a nueve días presentaron el mismo riesgo
clínico. Mientras el 13,3% de los pacientes hospitalizados menos de nueve días tuvo
riesgo clínico medio, y solo el 1,3% de pacientes internados más de 9 días presento
dicho riesgo clínico. Por último, el 6,7% de los pacientes cuyo tiempo dentro del
nosocomio fue menor a los nueve días presentaron riesgo clínico bajo. A través de la
prueba de independencia de chi-cuadrado, el p valor obtenido fue < 0,05,
demostrándose que las condiciones del paciente, las afecciones respiratorias,
temperatura, afecciones cardiacas y nivel de consciencia influyen en la continuidad de
la estancia hospitalaria en un hospital de Lima, 2020. Por tanto, la investigación
concluye señalando que las condiciones de salud del paciente: afecciones
respiratorias, temperatura, afecciones cardiacas y nivel de consciencia influyen en la
continuidad de la estancia hospitalaria en un hospital de Lima, 2020
One-Pass Context-Based Tableaux Systems for CTL and ECTL
When building tableau for temporal logic formulae, applying a two-pass construction, we first check the validity of the given tableaux input by creating a tableau graph, and then, in the second “pass”, we check if all the eventualities are satisfied. In one-pass tableaux checking the validity of the input does not require these auxiliary constructions. This paper continues the development of one-pass tableau method for temporal logics introducing tree-style one-pass tableau systems for Computation Tree Logic (CTL) and shows how this can be extended to capture Extended CTL (ECTL). A distinctive feature here is the utilisation, for the core tableau construction, of the concept of a context of an eventuality which forces its earliest fulfilment. Relevant algorithms for obtaining a systematic tableau for these branching-time logics are also defined. We prove the soundness and completeness of the method. With these developments of a tree-shaped one-pass tableau for CTL and ECTL, we have formalisms which are well suited for the automation and are amenable for the
implementation, and for the formulation of dual sequent calculi. This brings us one step closer to the application of one-pass context-based tableaux in certified model checking for a variety of CTL-type branching-time logics.Authors have been supported by the European Union (FEDER funds) under grant TIN2017-86727-C2-2-R, and by the University of the Basque Country under Project LoRea GIU18-182
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