The validity of the Hoffman and Emery equation in thermal diffusion

The most widely used equation in thermal diffusion is discussed in what concerns its range of validity. It is shown that when the separation curves are non-symmetrical with respect to the initial composition the error involved in the Hoffman and Emery equation when using a value of t=0.3 tr for the lower limit of the time, may be significantly larger than those predicted by their original authors. Experimental cases described in the literature are discussed on the light of previous analysis

Uso de extractos bioactivos de plantas em cosmecêuticos hidratantes no tratamento de feridas recalcitrantes e UPP

https://www.youtube.com/watch?v=rFR6xvDkDjkO interesse e conhecimento científico sobre a actividade benéfica de plantas e os seus compostos na saúde humana têm aumentado consideravelmente nos últimos anos. Isto tem permitido o desenvolvimento de diversos fármacos e nomeadamente cosmecêuticos contendo princípios activos de plantas, amplamente utilizados na prática clínica em todo o mundo. No presente trabalho, a utilização e optimização, entre outros, dos óleos de Azadirachta indica (Neem) e Pongamia glabra (Karanja), e do gel de Aloe barbadensis.extratos, resultou na criação de uma gama de cosmecêuticos – Gulk Neem. Estas formulações foram testadas em voluntários adultos (mais de 150) com patologias de pele diversas, incluindo psoríase, queimaduras, feridas crónicas e agudas graves, e úlceras de pressão (UP). A sinergia das propriedades destas plantas, em situações específicas de tratamento, originou resultados muito positivos, associados a um elevado grau de hidratação da pele, e contribuindo para a regeneração celular da mesma. As evidências clínicas têm mostrado que estas formulações têm, no mínimo, uma eficácia semelhante, quando comparados a outros tratamentos convencionais. Em todos os casos, após aplicações repetidas e de duração variável, conforme a gravidade da situação, foram observadas melhorias notórias e o tratamento completo das patologias, sem efeitos colaterais de destaque. Outros estudos estão em curso, para desenvolver novos produtos e validar em termos biológicos e celulares os efeitos observados.FCTinfo:eu-repo/semantics/publishedVersio

Nonsymmetrical separations in thermal diffusion columns

The influence of the feed composition upon the actual degrees of separation attained at the top and bottom sections of a thermogravitational column is discussed using the classical phenomenological theory of Furry, Jones, and Onsager. It is shown that, except for a feed composition of C 0 = 0.5 (mass fraction), the separation profile is nonsymmetric, i.e., the separations in the top and bottom sections of the column are nonsymmetric with respect to the feed composition, the asymmetry increasing as the feed composition moves away from C 0 = 0.5. An equation for the determination of the optimum feed location as a function of the feed composition is derived

Evaluation of antimicrobial activity in products containing Neem oil

Neem oil is obtained from seeds of Azadirachta indica, which present 30 to 50% (w/w) of oil per seed. Neem oil has been associated with a great diversity of beneficial properties, namely antimicrobial, anti-inflammatory and insecticide. Information concerning the antibacterial activity of Neem oil is scarce. Although the existing studies have demonstrated activity against both Gram+ and Gram- bacteria, the results are in some cases contradictory and do not include a significant number of organisms, namely organisms associated with skin infections.info:eu-repo/semantics/publishedVersio

Climate change impacts in the design of drainage systems: case study of Portugal

This paper aims to assess the necessity of updating the intensity-duration-frequency (IDF) curves used in Portugal to design building storm-water drainage systems. A comparative analysis of the design was performed for the three predefined rainfall regions in Portugal using the IDF curves currently in use and estimated for future decades. Data for recent and future climate conditions simulated by a global and regional climate model chain are used to estimate possible changes of rainfall extremes and its implications for the drainage systems. The methodology includes the disaggregation of precipitation up to subhourly scales, the robust development of IDF curves, and the correction of model bias. Obtained results indicate that projected changes are largest for the plains in southern Portugal (5–33%) than for mountainous regions (3–9%) and that these trends are consistent with projected changes in the long-term 95th percentile of the daily precipitation throughout the 21st century. The authors conclude there is a need to review the current precipitation regime classification and change the new drainage systems towards larger dimensions to mitigate the projected changes in extreme precipitation

Pensar o professor de educação online em tempos de cibercultura

This article is an excerpt from my doctoral thesis in education with a focus on the human / professional / teacher inserted in Online Education, with a view to the issues of the formation of teachers in the appropriation of new digital information and communication technologies (TDIC), in the perspective of postmodernity in the middle of cyberculture. We seek to theoretically discuss the teacher of online education from traditional teaching, who is challenged in his teaching-learning practice and feels the impacts of the gaps in his education, calling on everyone involved in this process to rethink new training practices that he takes into account, reflection, critical sense and humanism.Este artículo es un extracto de una tesis doctoral con un enfoque en el humano/profesional/profesor insertado en la educación en línea, con vistas a las cuestiones de la formación de los profesores en la apropiación de tecnologias digitales de información y comunicación (TDIC), desde la perspectiva de la postmodernidad en medio de la era de la cibercultura. Discutimos teóricamente el profesor de educación en línea que proviene de la enseñanza tradicional, que se encuentra desafiado en su práctica de enseñanza y aprendizaje y siente los impactos de las lagunas en su formación, haciendo un llamado a todos los involucrados en este proceso para repensar nuevas prácticas de formación, considerando la reflexión, el sentido crítico y el humanismo.Cet article est un extrait de une thèse de doctorat en éducation, en mettant l'accent sur l'humain / professionnel / enseignant inséré dans l'éducation en ligne, en vue des questions de la formation de les enseignants dans l'appropriation des TDIC, dans la perspective de la postmodernité au cœur de la cyberculture. Nous cherchons à discuter théoriquement de l'enseignant de l'enseignement en ligne, qui est mis au défi dans sa pratique d'enseignement-apprentissage et ressent les impacts des lacunes de son éducation, en appelant toutes les personnes impliquées dans ce processus à repenser les nouvelles pratiques de formation, considérant réflexion, sens critique et humanisme.Este artigo é um recorte da uma tese de doutoramento em educação com foco no ser humano/profissional/professor inserido na Educação online, com vistas às questões da formação de professores na apropriação de novas tecnologias digitais da informação e comunicação (TDIC), na perspectiva da pós-modernidade em plena era da cibercultura. Buscamos discutir teoricamente o professor da educação online advindo do ensino tradicional, o qual se vê desafiado na sua prática de ensino-aprendizagem e sente os impactos das lacunas em sua formação, conclamando todos envolvidos nesse processo a repensar novas práticas formativas, considerando a reflexão, o senso crítico e o humanismo

Azadirachta indica A. Juss. In Vivo Toxicity—An Updated Review

The Neem tree, Azadirachta indica A. Juss., is known for its large spectrum of compounds with biological and pharmacological interest. These include, among others, activities that are anticancer, antibacterial, antiviral, and anti-inflammatory. Some neem compounds are also used as insecticides, herbicides, and/or antifeedants. The safety of these compounds is not always taken into consideration and few in vivo toxicity studies have been performed. The current study is a literature review of the latest in vivo toxicity of A. indica. It is divided in two major sections—aquatic animals toxicity and mammalian toxicity—each related to neem’s application as a pesticide or a potential new therapeutic drug, respectively.info:eu-repo/semantics/publishedVersio

Chemistry, bioactivities, extraction and analysis of azadirachtin: State-of-the-art

Azadirachta indica A. Juss. (Neem) is an Indian tree recognized for its activity as pesticide, as well as several pharmacological properties. Among the various compounds already isolated and studied from Neem tree, azadirachtin (AZA) was identified as the main bioactive compound. Azadirachtin can be found at different parts of the Neem plant but assumes its maximum concentration at the seed level. This compound features a quite complex chemical structure, which justifies the 20-plus-year difficulty to identify the synthetic pathway that subsequently permitted to carry out its artificial synthesis. Azadirachtin is widely used as a basis for production of biopesticides; nevertheless, other properties have been recognized for this substance, among which the anticancer and antimalarial activity stand out. The methods available for azadirachtin extraction are diverse, including solid-liquid extraction and extraction with solvents at high or low temperatures. Alcohol based solvents are associated with higher extraction yields and are therefore preferred for the isolation of azadirachtin from plant parts. Clean-up of the extracts is generally required for further purification. The highest azadirachtin levels have been obtained from Neem seeds but concentration values present a large variation between batches. Therefore, in addition to extraction procedures, it is essential to establish routine methods for azadirachtin identification and quantification. Chromatography-based techniques are preferably selected for detection and quantification of azadirachtin in plant matrices. Overall, this process will guarantee a future reproducible, safe and effective use of the extracts in formulations for commercial applications.info:eu-repo/semantics/publishedVersio

Virtual model of an orthosis-chair mobility platform for domestic environments

[Resumen] Dada una plataforma híbrida silla-ortesis que permita gestionar movilidad, postura y actuación, es necesario controlar numerosos grados de libertad. Para que la plataforma sea funcional, es necesario asegurar que el comportamiento cinemático y dinámico de dichos grados de libertad haga posible realizar tareas habituales. El presente artículo estudia mediante simulación un caso de uso correspondiente a la realización de una tarea (preparar una taza de té) en un entorno doméstico (cocina) por parte de una persona usuaria de una plataforma silla-ortesis con arquitectura POSMOFYA. Dicho caso de uso comienza con un modelado en un entorno virtual 3D, del cual se extrae la evolución de la cinemática de la plataforma híbrida y su contexto. A continuación, se realiza un estudio dinámico inverso para obtener los valores necesarios de fuerzas y pares de los actuadores. La resolución del caso de estudio permite validar el funcionamiento de la arquitectura propuesta y también dimensionar la motorización necesaria para la plataforma ortesis-silla.[Abstract] Given a hybrid orthosis-chair platform that allows managing mobility, posture, and actuation, it is necessary to control a large number of degrees of freedom. For the platform to be functional, it is necessary to ensure that the kinematic and dynamic behavior of these degrees of freedom makes it possible to perform common tasks. This article studies by simulation a case study consisting of performing a task (preparing a cup of tea) in a domestic environment (kitchen) by a user of an orthosis-chair platform with POSMOFYA architecture. This use case begins with a 3D virtual environment modeling, from which the evolution of the kinematics of the hybrid platform and its context are extracted. Then, a reverse dynamic study is performed to obtain the necessary values of forces and torques of the actuators. The resolution of the case study allows to validate the operation of the proposed architecture and to dimension the necessary motorization for the orthosis-chair platform.Ministerio de Ciencia e Innovación; PID2020-116091RB-I0