30 research outputs found
Final Assessment of Preindustrial Solid-State Route for High-Performance Mg-System Alloys Production: Concluding the EU Green Metallurgy Project
No full textThe Green Metallurgy Project, a LIFE+ project co-financed by the European Union Commission, has now been completed. The purpose of the Green Metallurgy Project was to establish and assess a preindustrial process capable of using nanostructured-based high-performance Mg-Zn(Y) magnesium alloys and fully recycled eco-magnesium alloys. In this work, the Consortium presents the final outcome and verification of the completed prototype construction.
To compare upstream cradle-to-grave footprints when ternary
nanostructured Mg-Y-Zn alloys or recycled eco-magnesium chips are produced during the process cycle using the same equipment, a life cycle analysis was completed following the ISO 14040 methodology. During tests to fine tune the prototype machinery and compare the quality of semifinished bars produced using the scaled up system, the Buhler team produced interesting and significant results. Their tests showed the ternary Mg-Y-Zn magnesium alloys to have a highest specific strength over 6000 series wrought aluminum alloys usually employed in automotive components
High performance Mg-system alloys for weight saving applications: First year results from the green metallurgy EU project
No full textThe GREEN METALLURGY Project, a LIFE+ project co-financed by the EU Commission, has just concluded its first year. The Project seeks to set manufacturing processes at a pre-industrial scale for nanostructured-based high-performance Mg-Zn(Y) magnesium alloys. The Project's goal is the reduction of specific energy consumed and the overall carbon-footprint produced in the cradle-to-exit gate phases. Preliminary results addressed potentialities of the upstream manufacturing process pathway. Two Mg-Zn(Y) system alloys with rapid solidifying powders have been produced and directly extruded for 100% densification. Examination of the mechanical properties showed that such materials exhibit strength and elongation comparable to several high performing aluminum alloys; 390 MPa and 440 MPa for the average UTS for two different system alloys, and 10% and 15% elongations for two system alloys. These results, together with the low-environmental impact targeted, make these novel Mg alloys competitive as lightweight high-performance materials for automotive components
Formulation of the organic solid waste management of the market square of the neighborhood Las Ferias located in the city of Bogotá
No full textLa gestión integral de residuos se considera como un conjunto de actividades encaminadas a reducir la generación de residuos, a realizar el aprovechamiento teniendo en cuenta sus características, volumen, procedencia, costos, tratamiento con fines de valorización energética, posibilidades de aprovechamiento y comercialización. En la localidad de Engativá, barrio las ferias no se cuenta con ningún plan de manejo de residuos ni con un PGIRS actualizado bajo la normatividad vigente, razón por la cual, en este trabajo se pretende realizar la formulación y evaluación de la gestión actual de esta plaza, ya que se buscará las mejores técnicas de aprovechamiento para el tratamiento de estos residuos y se diseñará el modelo del complejo de aprovechamiento. Se desarrollará una fase de identificación de organismos reguladores para la recopilación de la información inicial, una fase diagnostica de la gestión actual, contemplando la normatividad aplicable y los aspectos relevantes de la actividad realizada en la plaza de mercado, estudiando el uso de suelo y los conflictos asociados a este; evaluando los impactos negativos significativos vinculados a la generación de residuos.
Se identificó la forma actual de recolección y separación de los residuos, su segregación en cada punto de venta y la manipulación de estos, evidenciándose que el programa de separación tiene falencias en puntos críticos, por lo cual se propone implementar de manera eficiente una formulación de la gestión de residuos sólidos orgánicos para así poder evitar problemas de tipo ambiental ya que están dejando pasar por alto un valor agregado que se le puede dar a este tipo de residuos sólidos orgánicos.Universidad Libre, Facultad de Ingeniería, Especialización en Gerencia AmbientalComprehensive waste management is considered as a set of activities aimed at reducing waste generation, making use of it taking into account its characteristics, volume, origin, costs, treatment for energy recovery purposes, possibilities of use and commercialization. In the town of Engativá, barrio las ferias, there is no waste management plan or an updated PGIRS under current regulations, which is why this paper aims to formulate and evaluate the current management of this plaza, since the best exploitation techniques for the treatment of this waste will be sought and the model of the exploitation complex will be designed. A phase of identification of regulatory bodies will be developed for the compilation of the initial information, a diagnostic phase of the current management, contemplating the applicable regulations and the relevant aspects of the activity carried out in the market place, studying the use of land and the conflicts associated with it; evaluating the significant negative impacts linked to the generation of waste.
The current form of collection and separation of waste, its segregation at each point of sale and its handling were identified, evidencing that the separation program has shortcomings in critical points, for which it is proposed to efficiently implement a formulation of the management of organic solid waste in order to avoid environmental problems since they are overlooking an added value that can be given to this type of organic solid waste
A new lower limb portable exoskeleton for gait assistance in neurological patients: a proof of concept study
No full textBackground: Few portable exoskeletons following the assist-as-needed concept have been developed for patients with neurological disorders. Thus, the main objectives of this proof-of-concept study were 1) to explore the safety and feasibility of an exoskeleton for gait rehabilitation in stroke and multiple sclerosis patients, 2) to test different algorithms for gait assistance and measure the resulting gait changes and 3) to evaluate the user's perception of the device.
Methods: A cross-sectional study was conducted. Five patients were recruited (4 patients with stroke and 1 with multiple sclerosis). A robotic, one-degree-of-freedom, portable lower limb exoskeleton known as the Marsi Active Knee (MAK) was designed. Three control modes (the Zero Force Control mode, Mode 1 and Mode 3) were implemented. Spatiotemporal gait parameters were measured by the 10-m walking test (10MWT), the Gait Assessment and Intervention Tool (G.A.I.T.) and Tinetti Performance Oriented Mobility Assessment (gait subscale) before and after the trials. A modified QUEST 2.0 questionnaire was administered to determine each participant's opinion about the exoskeleton. The data acquired by the MAK sensors were normalized to a gait cycle, and adverse effects were recorded.
Results: The MAK exoskeleton was used successfully without any adverse effects. Better outcomes were obtained in the 10MWT and G.A.I.T. when Mode 3 was applied compared with not wearing the device at all. In 2 participants, Mode 3 worsened the results. Additionally, Mode 3 seemed to improve the 10MWT and G.A.I.T. outcomes to a greater extent than Mode 1. The overall score for the user perception of the device was 2.8 ± 0.4 95% CI.
Conclusions: The MAK exoskeleton seems to afford positive preliminary results regarding safety, feasibility, and user acceptance. The efficacy of the MAK should be studied in future studies, and more advanced improvements in safety must be implemented.G. Puyuelo-Quintana has received financial support by the “Doctorado Industrial” grant of Ministerio de Ciencia, Innovación y Universidades de España
(reference DI-16- 08731).
A. Plaza-Flores and E. Garces-Castellote have received financial support by
the “Doctorado Industrial” grant of Comunidad de Madrid (reference
IND2017/TIC-7698 and IND2018/TIC-9618, respectively).Peer reviewe
Entre nativos e de fora: estudo etnográfico sobre nuanças identitárias no Centro Histórico de cidade litorânea no sul do Brasil, Garopaba/SC
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Antropologia Social, Florianópolis, 2010Neste trabalho são analisadas questões relacionadas aos processos identitários recorrentes na cidade de Garopaba/SC, especificamente no centro histórico. Em tais processos, as relações entre "nativos" e "de fora" são dominantes. A análise permeou práticas e discursos de seus diversos moradores e freqüentadores. Constatou-se que para os "nativos" há um ideário comum ligado ao centro histórico, seja através das práticas atreladas ao mar, seja aos hábitos açorianos como os da pesca e das comidas, bem como as especificidades presentes nos jogos de comunicação, gírias locais, nomes dados aos becos do centro histórico, a tradição da organização da festa de Nossa Senhora dos Navegantes, entre outras. Para eles, "Os ?de fora' sempre serão "de fora"'. Já, para os "de fora", os "nativos" precisam ser conscientizados de seus valores, de suas paisagens, de seus bem patrimoniais, para assumirem sua condição de "nativos". Esta série de percepções e sentidos que abarcam as identidades em Garopaba, particularmente no centro histórico, oscilam entre posições e lugares caracterizados por certa fluidez e flexibilidade. Pode-se concluir que os contornos territoriais do centro histórico, aliados às práticas e aos usos realizados naquele local, expressam as características presentes em tais relações
Safety and usability of the MAK exoskeleton in patients with stroke
No full text[Background and purpose] Stroke is one of the leading causes of disability in adults worldwide, and one of the main objectives in the rehabilitation of these patients is to recover the gait. New technologies have emerged to cope with this issue, complementing conventional therapy with the use of devices such as exoskeletons. The Marsi Active Knee (MAK) exoskeleton (Marsi Bionics SL, Madrid, Spain) has already been tested, but an updated version was improved to allow the patients to perform functional exercises. The aim of this study was to assess the safety and usability of the MAK in the stroke population as well as its potential clinical effects.[Methods] A single-group open label intervention trial was conducted. The device was used twice a week for 5 weeks during 1 h per visit. During the visits, sit-to-stand transitions, walking, stair climbing, trunk rotations, and weight-transfer exercises were performed using the device. Adverse events were collected from participants and therapists to assess safety. The Quebec User Evaluation of the Satisfaction with assistive Technology (QUEST 2.0) was used by both therapists and participants to assess usability. To evaluate its clinical effects, active range of motion (ROM) and muscle strength were assessed in the lower limb.[Results] Six participants with stroke were recruited. The device was shown to be safe since no serious adverse events were reported neither by patients nor by therapists. Every proposed exercise was performed. Regarding clinical effects, overall muscle strength showed an increase after the treatment, although ROM measurements did not show any difference.[Discussion] Our results suggest that the MAK device is safe for stroke patients. Nevertheless, further changes to enhance usability are recommended, such as an improvement of the attachment system and an adaptation for the drop foot. Beneficial effects regarding increases in muscle strength were obtained. Further trials with a larger sample size, longer intervention periods, and a control group are needed to verify these results. Also, future research should focus on the usability of the MAK as an assistive technology.This work was partially funded by Agencia Estatal de Investigación through grant PID2019-110492RB-I00 and from Comunidad de Madrid through Grant IND2018/TIC9618. C-T acknowledges support from Consejería de Educación e Investigación de la Comunidad de Madrid through Grant PEJ-2019-AI_TIC-15202. G-Ca acknowledges support from Comunidad de Madrid through Grant IND2018/TIC9618 and the University of Alcala. P-F acknowledges support from Comunidad de Madrid through Grant IND2017_TIC-7698.Peer reviewe
Evaluation of the impact of CloudLabs® and PhET on the learning of kinematics: Comparison with the traditional method in tenth grade students
No full textEsta investigación evalúa el impacto de herramientas tecnológicas, específicamente CloudLabs® y el simulador PhET, en comparación con el método tradicional de enseñanza, sobre el aprendizaje de la cinemática en estudiantes de décimo grado de la Institución Educativa Magdalena Ortega. Se emplearon tres instrumentos para la recolección de datos: una encuesta de caracterización de la población, un pre-test y un post-test. Basado en los resultados del pre-test y la caracterización estudiantil, se diseñó una unidad didáctica incorporando CloudLabs® y PhET, con el propósito de evaluar su impacto en el rendimiento académico frente al método tradicional. El análisis de los datos se realizó con el software estadístico Stata, utilizando medidas de tendencia central y dispersión para variables cuantitativas, y frecuencias absolutas y relativas para variables cualitativas. La prueba de Kolmogorov-Smirnov se utilizó para evaluar la normalidad de las variables y determinar la necesidad de pruebas paramétricas o no paramétricas. Los resultados muestran que CloudLabs® tuvo un efecto positivo y significativo en el rendimiento académico de los estudiantes, logrando puntuaciones superiores en comparación con el método tradicional. En contraste, aunque el simulador PhET también mejoró el desempeño académico del 94% de los estudiantes, su impacto no alcanzó el nivel de eficacia observado con CloudLabs®. Estos hallazgos sugieren que la integración de herramientas tecnológicas en la enseñanza de la cinemática puede ofrecer mejoras sustanciales en el rendimiento académico.Magíster en Innovación y Tecnología para la EducaciónMaestríaThis research evaluates the impact of technological tools, specifically CloudLabs® and the PhET simulator, compared to the traditional teaching method, on the learning of kinematics in tenth grade students of the Magdalena Ortega Educational Institution. Three instruments were used for data collection: a population characterization survey, a pre-test and a post-test. Based on the results of the pre-test and the student characterization, a teaching unit was designed incorporating CloudLabs® and PhET, with the purpose of evaluating their impact on academic performance compared to the traditional method. Data analysis was performed with the Stata statistical software, using measures of central tendency and dispersion for quantitative variables, and absolute and relative frequencies for qualitative variables. The Kolmogorov-Smirnov test was used to assess the normality of the variables and determine the need for parametric or non-parametric tests. The results show that CloudLabs® had a positive and significant effect on the academic performance of students, achieving higher scores compared to the traditional method. In contrast, although the PhET simulator also improved academic performance for 94% of students, its impact did not reach the level of effectiveness observed with CloudLabs®. These findings suggest that integrating technological tools into the teaching of kinematics can offer substantial improvements in academic performance
Integration methods for enhanced trapping and spectroscopy in optofluidics
No full text“Lab on a Chip” technologies have revolutionized the field of bio-chemical analytics. The crucial role of optical techniques in this revolution resulted in the emergence of a field by itself, which is popularly termed as “optofluidics”. The miniaturization and integration of the optical parts in the majority of optofluidic devices however still remains a technical challenge. The works described in this thesis focuses on developing integration methods to combine various optical techniques with microfluidics in an alignment-free geometry, which could lead to the development of portable analytical devices, suitable for field applications.
The integration approach was applied to implement an alignment-free optofluidic chip for optical chromatography; a passive optical fractionation technique fractionation for cells or colloids. This system was realized by embedding large mode area photonic crystal fiber into a microfluidic chip to achieve on-chip laser beam delivery. Another study on passive sorting envisages an optofluidic device for passive sorting of cells using an optical potential energy landscape, generated using an acousto-optic deflector based optical trapping system.
On the analytical side, an optofluidic chip with fiber based microfluidic Raman spectroscopy was realized for bio-chemical analysis. A completely alignment-free optofluidic device was realized for rapid bio-chemical analysis in the first generation by embedding a novel split Raman probe into a microfluidic chip. The second generation development of this approach enabled further miniaturization into true microfluidic dimensions through a technique, termed Waveguide Confined Raman Spectroscopy (WCRS). The abilities of WCRS for online process monitoring in a microreactor and for probing microdroplets were explored. Further enhanced detection sensitivity of WCRS with the implementation of wavelength modulation based fluorescent suppression technique was demonstrated. WCRS based microfluidic devices can be an optofluidic analogue to fiber Raman probes when it comes to bio-chemical analysis. This allows faster chemical analysis with reduced required sample volume, without any special sample preparation stage which was demonstrated by analyzing and classifying various brands of Scotch whiskies using this device. The results from this study also show that, along with Raman spectroscopic information, WCRS picks up the fluorescence information as well, which might enhance the classification efficiency.
A novel microfabrication method for fabricating polymer microlensed fibers is also discussed. The microlensed fiber, fabricated with this technique, was combined with a microfluidic gene delivery system to achieve an integrated system for optical transfection with localized gene delivery
The terrain of health policy analysis in low and middle income countries: a review of published literature 1994-2007.
No full textThis article provides the first ever review of literature analysing the health policy processes of low and middle income countries (LMICs). Based on a systematic search of published literature using two leading international databases, the article maps the terrain of work published between 1994 and 2007, in terms of policy topics, lines of inquiry and geographical base, as well as critically evaluating its strengths and weaknesses. The overall objective of the review is to provide a platform for the further development of this field of work. From an initial set of several thousand articles, only 391 were identified as relevant to the focus of inquiry. Of these, 164 were selected for detailed review because they present empirical analyses of health policy change processes within LMIC settings. Examination of these articles clearly shows that LMIC health policy analysis is still in its infancy. There are only small numbers of such analyses, whilst the diversity of policy areas, topics and analytical issues that have been addressed across a large number of country settings results in a limited depth of coverage within this body of work. In addition, the majority of articles are largely descriptive in nature, limiting understanding of policy change processes within or across countries. Nonetheless, the broad features of experience that can be identified from these articles clearly confirm the importance of integrating concern for politics, process and power into the study of health policy. By generating understanding of the factors influencing the experience and results of policy change, such analysis can inform action to strengthen future policy development and implementation. This article, finally, outlines five key actions needed to strengthen the field of health policy analysis within LMICs, including capacity development and efforts to generate systematic and coherent bodies of work underpinned by both the intent to undertake rigorous analytical work and concern to support policy change
Evaluación resistográfica en elementos de maderas desfibradas de la torre de lixiviación de la oficina salitrera Santa Laura en Chile. Patrimonio de la Humanidad
No full textThe leaching tower is located in the Santa Laura saltpeter works office in Chile. In recent years studies have been carried out, using Non Destructive Techniques (TND), which have determined that the tower is in good condition. However, there are doubts regarding the actual dimensions of the construction elements affected by the desfibration. The present study had the objective of evaluate defibred wood elements, from the leaching tower of the Santa Laura saltpeter works office, using the resistography technique. Additional studies of ultrasound and xylohigrometry were also developed. The obtained results establish that the reduction of the dimensions of the evaluated elements does not present significant difference and that there are no deep damages in the woods. The study confirms that the building is not at risk.La torre de lixiviación se encuentra ubicada en la oficina salitrera Santa Laura en Chile. En los últimos años se han realizado estudios, mediante Técnicas No Destructivas (TND), los que han determinado que la torre se encuentra en buen estado. No obstante, existen dudas respecto a las reales dimensiones de los elementos constructivos afectados por el desfibrado. El presente estudio tuvo como objetivo evaluar elementos de madera desfibrada, de la torre de lixiviación de la oficina salitrera Santa Laura, mediante la técnica de resistografía. Estudios adicionales de ultrasonido y xilohigrometría también fueron desarrollados. Los resultados obtenidos establecen que la disminución de las dimensiones de los elementos evaluados no presenta diferencia significativa y que no existen daños profundos en las maderas. El estudio confirma que el edificio no se encuentra en riesgo
