SOLVENT EFFECT ON PHOTOSTABILITY OF BUTYL METHOXY DI BENZOYL METHANE FORMULATED IN SOLUTION AND EMULSION

Objective: The current study was undertaken to correlate the impact of some cosmetics solvents in the photostability of butyl methoxy dibenzoyl methane (BMDBM) into systems with an increasing order of complexity, from simple solutions to emulsions.Methods: Solutions and emulsions containing BMDBM in different solvents were prepared and evaluated using spectrophotometer or transmittance analyzer, respectively. Also, emulsions containing BMDBM in combination with octyl methoxycinnamate (OMC) in ratio 1:1 and 1: 2, and in the presence of octocrylene in the ratio 1:2:1 were prepared. The percentage of decay absorbance at 356 nm was measured before and after irradiation at 500 W/m2 at intervals of 20 min until completing 100 min. Finally, a photolysis assay was carried to analyze deoxygenated and not BMDBM solutions.Results: The absorbance decay of BMDBM in solution was higher in solvents such as mineral oil, isopropyl palmitate and isopropyl myristate. Also, it was observed that concentration and degassing had an effect on the decay kinetics. In emulsions containing only, BMDBM, the absorbance decay did not exceed 20% in all solvents, suggesting a protective effect of the matrix. In the contrary, a decay of 90% was observed in emulsion containing BMDBM and OMC in a 1:2 ratio. When Oct was added to that emulsion, stabilization on the absorbance decay of BMDBM was detected.Conclusion: This study evidenced that the photochemistry of BMDBM is different in solutions and in emulsions. In solutions, the nature of solvents was important, while in emulsions the nature of UVB filters played a pivotal role in the stability of BMDBM.Â

Proporción ideal para la elaboración de ladrillos en base a papel bond reciclado para muros no portantes

La presente investigación buscó determinar la proporción ideal para la elaboración de ladrillos en base a papel bond reciclado para muros no portantes, es decir para muros internos o tabiquerías Para poder lograr este objetivo se prepararon 5 mezclas según las siguientes proporciones 1:1:1, 1:1:2, 1:1:3, 1:2:2 y 1:2:3 (cemento:arena:papel bond reciclado), se prepararon cubos de 10 cm de arista y se dejaron secar por 28 días, luego de esto se sometieron a ensayo de compresión con ayuda de una prensa hidráulica Luego de realizar los ensayos respectivos, se procesaron los datos y se evaluó lo planteado inicialmente haciendo comparaciones con la resistencia mínima exigida en las normas E.080 “Diseño y construcción con tierra reforzada” y E.070 “Albañilería” del Reglamento Nacional de Edificaciones. El análisis estadístico (ANOVA y Prueba de Tukey) permitió concluir que la proporción ideal para elaborar ladrillos en base a papel bond reciclado fue la proporción 1:1:1, la cual no sólo superó lo estipulado en la norma E.080 para adobes y la E.070 para bloques de muros no portantes, sino también lo que indica la norma E.070 para bloques de muros portantes, ladrillos tipo I y tipo II, pudiendo ser usados para construcciones generales en zonas sísmicas 2 y 3 en edificios de hasta 2 pisos.Tesi

Start-up Optimization of a Combined Cycle Power Plant

In the electricity market of today, with increasing demand for electricity production on short notice, the combined cycle power plant stands high regarding fast start-ups and efficiency. In this paper it has been shown how the dynamic start-up procedure of a combined cycle power plant can be optimized using JModelica. org, proposing a way to minimize the start-up time while maximizing the power production during start-up. The physical models have been developed in Modelica, adapted to suit optimization purposes and extended to optimization problems. Constraints keeping the lifetime consumption of critically stressed components under control are limiting factors. The plant models have been successfully optimized to full load

Start-up Optimization of a Combined Cycle Power Plant

In the electricity market of today, with increasing demand for electricity production on short notice, the combined cycle power plant stands high regarding fast start-ups and efficiency. In this paper it has been shown how the dynamic start-up procedure of a combined cycle power plant can be optimized using JModelica. org, proposing a way to minimize the start-up time while maximizing the power production during start-up. The physical models have been developed in Modelica, adapted to suit optimization purposes and extended to optimization problems. Constraints keeping the lifetime consumption of critically stressed components under control are limiting factors. The plant models have been successfully optimized to full load

Comparison of on-line Teaching and Face-to-face Teaching

AbstractFor many years, we have been using on-line courses in teaching German. Language. After several years of validation of courses that we created, we tried a small study, to demonstrate how effective the use of ICT in teaching is. To identify the relationship of students to ICT and to determine students’ views on teaching supported by ICT, we used the method of questionnaire. All questions were closed and offered a choice of several options. Research was initiated in the school year 2008/09 and was carried out in two phases

Estudio del estrés laboral en las áreas de Talento Humano y Administrativo, en el Ministerio de Telecomunicaciones y de la Sociedad de la Información (Mintel), con el fin de mejorar el desempeño laboral mediante estrategias de afrontamiento, en el año 2021- 2022

Finally, the study allowed us to conclude that the current situation of public servants in relation to their working hours is a stress condition that generates a low relationship in the rates of production and work performance, this being the main cause of the excess workload compared to the new modality implemented due to the presence of biological risk.Work stress according to the ILO(2014),indicates that it is the reaction that an individual may have to requirements and work pressures that do not fit their knowledge and skills that test their ability to cope with the situation (World Health Organization, 2018). In this sense, the presence of this factor has influenced harmful consequences that have caused employees to present job dissatisfaction, absenteeism and/or lack of commitment. As a result of the presence of Covid-19, a new work modality was implemented in Ecuador that led to the exacerbation of said problem in MINTEL workers. The intervention, the objective of this study is to resignify the situation of work stress in the human talent and administrative areas of the Ministry of Telecommunications and the MINTEL Information Society. The research is based on a cross-sectional study with a sample of 40 people from the area of human and administrative talent compared to a population of 212 who are part of the institution. The method used was the survey, to identify the causes generated by this factor against the performance of MINTEL workers, which consists of 6 items. On the other hand, the WHO-ILO questionnaire was carried out to recognize the level of work stress, therefore, the questionnaire consists of 25 items that assess the different types of work stressors, focusing on various aspects. The methodology for this intervention was based on tools on virtual platforms and in this way; A proposal is proposed where the main solutions are considered to take actions that help reduce work stress and improve the performance of public servants through developed coping strategies. The results obtained allowed to propose coping strategies with respect to the organization, for the areas of human and administrative talent, thus generating potential for their work performance based on the implementation of techniques and procedures, which will overcome the lack of productivity found in the employees of these areas.Finally, the study allowed us to conclude that the current situation of public servants in relation to their working hours is a stress condition that generates a low relationship in the rates of production and work performance, this being the main cause of the excess workload compared to the new modality implemented due to the presence of biological risk

El impedimento de inscripción del nacimiento y la afectación del derecho de igualdad del padre que procrea mediante técnicas de reproducción asistida, 2019

El presente trabajo de investigación, surge como problema de los cambios sociales y avances científicos, por ello se estableció como objetivo general determinar la afectación del derecho de igualdad del padre que procrea mediante Técnicas de Reproducción Asistida en la inscripción de nacimiento. El estudio es de tipo cualitativo, para la recolección de datos se aplicó entrevistas y se analizó sentencia extranjera, lo que permitió determinar la afectación del derecho de igualdad del padre que se somete a TERAS, puesto que mencionado derecho no se encuentra garantizado completamente en la sociedad, así mismo al no existir una regulación especial sobre TERAS, conllevó a las investigadoras a considerar necesaria la modificación del artículo 21 del Código Civil en donde faculte al padre inscribir a sus hijos con sus apellidos cuando la madre permanezca en anonimato

Computer-aided detection (CAD) for breast MRI: evaluation of efficacy at 3.0 T

OBJECTIVE: The purpose of the study was to evaluate the accuracy of 3.0-T breast MRI interpretation using manual and fully automated kinetic analyses. MATERIAL AND METHODS: Manual MRI interpretation was done on an Advantage Workstation. Retrospectively, all examinations were processed with a computer-aided detection (CAD) system. CAD data sets were interpreted by two experienced breast radiologists and two residents. For each lesion automated analysis of enhancement kinetics was evaluated at 50% and 100% thresholds. Forty-nine malignant and 22 benign lesions were evaluated. RESULTS: Using threshold enhancement alone, the sensitivity and specificity of CAD were 97.9% and 86.4%, respectively, for the 50% threshold, and 97.9% and 90%, respectively, for the 100% threshold. Manual interpretation by two breast radiologists showed a sensitivity of 84.6% and a specificity of 68.8%. For the same two radiologists the mean sensitivity and specificity for CAD-based interpretation was 90.4% (not significant) and 81.3% (significant at p < 0.05), respectively. With one-way ANOVA no significant differences were found between the two breast radiologists and the two residents together, or between any two readers separately. CONCLUSION: CAD-based analysis improved the specificity compared with manual analysis of enhancement. Automated analysis at 50% and 100% thresholds showed a high sensitivity and specificity for readers with varying levels of experience

Cohetes de agua en miniatura

En el presente artículo se describe cómo a partir de la experimentación directa con la construcción de una maqueta con materiales caseros se puede demostrar los enunciados de las leyes de la física, como conservación de cantidad de movimiento, lanzamiento vertical y la tercera ley de Newton. Este experimento denominado «Cohetes de agua miniatura» pretende consolidar los conocimientos de las fórmulas expuestas en clase. El estudio quedará documentado en una página web donde cualquier persona accede a la información para que pueda realizar el experimento en su casa y comprenda de mejor manera los enunciados de las leyes