324 research outputs found
Análisis de tendencias en las investigaciones realizadas a partir de los datos del Proyecto PISA
Este estudio es parte de una investigación más amplia que pretende diseñar un modelo de análisis de evaluaciones de sistemas educativos que permita valorar su aportación para la cohesión social (Jornet, 2012). El punto de partida son investigaciones previas sobre el papel de las variables de contexto, de entrada y de proceso en las evaluaciones de sistemas educativos, que frecuentemente cuidan mucho más la justificación teórica y la calidad métrica de las variables de producto que estas otras, que finalmente ayudan a interpretar los resultados. En este caso realizamos revisión de los trabajos científico-académicos del corte empírico, publicados entre los años 2000 y 2012, que utilizan bases de datos PISA. La metodología se estructura en dos fases: identificación y selección de los documentos para formar una base y posterior análisis de cada uno de los documentos con el fin de extraer indicadores que nos permitieran realizar un análisis exploratorio. Algunos resultados hacen pensar que las bases de datos PISA están infrautilizadas, sobre todo por los investigadores en el campo de educación.This study is part of a broader research that aims to design a model of analysis of educational systems assessment, based in social cohesion (Jornet, 2012). The starting point is located in previous research about the context variables; it is cared more frequently a theoretical justification and metric quality of output variables, leaving aside the variables that can help interpret the results. In our case, we conducted a review of the scientific literature, based in empirical papers that use PISA database and published between 2000 and 2012. The methodology is structured in two phases: identification and selection of documents and further analysis of these documents. The analysis of documents consists of identifying certain indicators in order to explore. Some results suggest that researchers in the field of education underuse PISA databases
Vitrification of Donkey Sperm: Is It Better Using Permeable Cryoprotectants?
Vitrification by direct exposure of sperm to liquid nitrogen is increasing in popularity as an alternative to conventional freezing. In this study, the effect of permeable cryoprotectant agents for donkey sperm vitrification was compared to an extender containing non-permeable cryoprotectants. First, three different concentrations of sucrose (0.1, 0.2, and 0.3 molar, M) and bovine serum albumin, BSA (1, 5, and 10%) were compared. Secondly, the concentration of non-permeable agents producing the most desirable results was compared to an extender containing glycerol as permeable agent. Vitrification was performed by dropping 30 μL of sperm suspension directly into LN2 and warming at 42 °C. Sperm motility (total, TM; and progressive, PM) and plasma membrane integrity, PMI (mean ± SEM) were statistically compared between treatments. Sucrose 0.1 M showed a significantly higher percentage of total sperm motility (21.67 ± 9.22%) than sucrose 0.2 M (14.16 ± 4.50%) and 0.3 M (8.58 ± 6.22%); and no differences were found in comparison to the control (19.71 ± 10.16%). Vitrification with sucrose 0.1 M or BSA 5% obtained similar results for TM (21.67 ± 9.22% vs. 19.93 ± 9.93%), PM (13.42 ± 6.85% vs. 12.54 ± 6.37%) and PMI (40.90 ± 13.51% vs. 37.09 ± 14.28); but both showed higher percentages than glycerol (TM = 9.71 ± 4.19%; PM = 5.47 ± 3.17%; PMI = 28.48 ± 15.55%). In conclusion, donkey sperm vitrification in spheres using non-permeable cryoprotectants exhibited better sperm motility and viability parameters after warming than sperm vitrification using extenders containing permeable cryoprotectants
Studies of the Microbiological and Physico-Chemical Composition of Goat ́s Milk from North-Western Spain
P. 39-44Twenty-seven samples of raw goat’s milk were collected from four
farms in the North-West of Spain with the aim of analysing counts of
various mesophilic bacteria and of determining the physical and chemical composition during different seasons of the year. Overall mean
values for mesophilic aerobic micro-organisms (Standard Plate Counts,
SPCs) were above 5.6 log cfu/ml, very similar to the counts on M17 agar
(presumptive Lactococcus, 5.6 log cfu/ml) and higher than the counts
on MSE agar (presumptive Leuconostoc, 4.6 log cfu/ml) and on MRS
agar (presumptive Lactobacillus, 4.4 log cfu/ml). Counts were generally
higher in winter than in spring and summer, although no statistically
significant differences were found. The microbiological quality of raw
goat’s milk produced in the farms investigated in the North-West of
Spain is only partially in accordance with European Union standards.
Hence, hygiene practices should be improved so as to decrease the
standard plate counts on some of the farms checked. The physical and
chemical composition tests also showed higher values for fat, protein
and dry extract during the winter season. The average fat content (5.5
g/100 ml) and dry extract (14.7 g/100 ml) were higher than the values
noted in other studies, making this of interest for cheese makingS
Multicomponent bioactive extract from red stage Haematococcus pluvialis wet paste: avoiding the drying step and toxic solvents
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/EQC2018-005011-P/ESThis study provides an efficient alternative by extracting bioactive compounds from Haematococcus pluvialis via matrix solid-phase dispersion (MSPD) from its wet form, reducing one of the process steps with the greatest economic impact, the drying of the microalga. To obtain a suitable extract for nutraceutical purposes, solvents with the generally recognised as safe (GRAS) designation (ethanol, ethyl lactate, and ethyl acetate) with limitations of use (acetone) and extractants with higher toxicity such as methanol and methyl-tert-butyl ether (MTBE) are contrasted. Through the optimisation of the extractive process, ethanol, a GRAS solvent, presents the best overall recovery for carotenoid compounds and fatty acids, showing an antioxidant activity of 1.58 mmolTE g−1 DW, comparable to its synthetic alternative of petrochemical origin without the drawback of having limitations in its food use. In addition, the identification of the phenolic compounds, phloroglucinol, p-coumaric acid, gallic acid, and catechin, not previously characterised in red stage H. pluvialis, provides a response to the phenolic activity present in the extract (24.65 mmolGAE g−1 DW). Comparison of the extractive efficiency obtained with the main methods for the extraction of carotenoids and fatty acids in H. pluvialis, in contrast to the proposed method, shows a positive feasibility of this approachOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by project ED431 2020/06 (Galician Competitive Research Groups Xunta de Galicia). This work was supported by project EQC2018-005011-P (Ministry of Science, Innovation and Universities, Spain). All these programmes are co-funded by FEDER (EU). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical SocietyS
Propuesta de programa de control de la exposición ocupacional a riesgos ergonómicos y a estrés térmico por calor para los colaboradores de las líneas de producción de la empresa HMA Maquilas S.A., ubicada en Heredia, Costa Rica
Proyecto de Graduación (Licenciatura en Ingeniería en Seguridad Laboral e Higiene Ambiental) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería en Seguridad Laboral e Higiene Ambiental, 2021El presente proyecto se desarrolló en la empresa HMA Maquilas S.A.,
localizada en Heredia, la cual se dedica a la maquila, embalaje, desembalaje,
etiquetado y distribución de bebidas y alimentos altamente consumidos en el país.
La investigación se realizó en las líneas de producción del área de planta, en las
que laboran 57 trabajadores y cuenta con nueve líneas de producción.
El objetivo general del proyecto es proponer un programa de control de la
exposición ocupacional a riesgos ergonómicos y a estrés térmico por calor para los
colaboradores de las líneas de producción; por tanto, para recolectar información
para identificar y evaluar las condiciones de riesgo ergonómico y exposición a calor,
se aplicaron herramientas propias y existentes, tales como encuestas, actas de
muestreo, cuadros de análisis, entre otras.
Como resultado de las condiciones de riesgo ergonómico se obtuvo que, 90
% de las actividades superaron el peso máximo recomendado según la ecuación
de NIOSH y la puntuación del Job Strain Index indicó alto riesgo en 77,27 % de las
tareas. Se concluye que las zonas del cuerpo más afectadas son la espalda alta y
baja, las manos y muñecas.
Por otro lado, los índices de estrés térmico de los seis empleados evaluados
del área de producción superaron los límites recomendados por la ACGIH para
carga de trabajo moderada y pesada (26 °C). En consecuencia, se concluye que
estos trabajadores se encuentran expuestos a estrés térmico por calor durante su
jornada laboral.
De esta manera, se propone la implementación del Programa de Control de
la Exposición Ocupacional a Riesgos Ergonómicos y Estrés Térmico por Calor para
los trabajadores de las líneas de producción, el cual incluye controles
administrativos e ingenieriles para mitigar los riesgos relacionados a los temas.The following project was developed in HMA Maquilas S.A., located in
Heredia. This organization dedicates to the assembly, packaging, unpacking,
labeling and distribution of highly consumed beverages and foods in the country.
The research focused on the production lines of the plant area, which has eight
active production lines and 57 employees.
The main objective of the project is to propose a program to control
occupational exposure to ergonomic risks and thermal stress due to heat for the
employees of the production lines; therefore, ergonomic risk conditions and heat
exposure were identified and evaluated. To collect information, own and existing
tools were applied, such as surveys, sampling reports, data analysis tables, among
others.
According to the NIOSH equation, 90 % of the activities exceeded the
recommended maximum weight and the Job Strain Index score indicated high risk
in 77,27 % of the tasks. As a result, it is concluded that the most affected body parts
are the upper and lower back, the hands and wrists.
Likewise, the heat stress index evaluated in the production area exceeded
the limits recommended by the ACGIH for moderate and heavy workload (26 °C).
Therefore, it is concluded that the employees are exposed to heat stress during their
working hours, where 72,20 % indicated that the exposure has affected their health.
In this manner, implementing the Program for the Control of Occupational
Exposure to Ergonomic Risks and Thermal Stress due to Heat for the workers of
the production lines, Will help to mitigate risks related to the issues already
mentioned through the administrative and engineering controls
Transfer of knowledge: is it a gender matter?
[ES] En 2018, el Ministerio de Ciencia, Innovación y Universidades convocó el nuevo Sexenio de Transferencia de Conocimiento e Innovación. Más de un año después ANECA publica los resultados en los que más de la mitad de las solicitudes no habían alcanzado los requisitos para que dicho sexenio fuese concedido. Del análisis de los resultados de una encuesta elaborada por la Asociación de Mujeres Investigadoras y Tecnólogas AMIT se destaca que las solicitudes evaluadas con éxito tenían un mayor porcentaje de aportaciones basadas en la Transferencia generadora de valor económico, mientras que las solicitudes evaluadas negativamente tenían un mayor porcentaje de aportaciones basadas en la Transferencia generadora de valor social. Este resultado explica que haya habido un mayor porcentaje de investigadores que de investigadoras con éxito en esta convocatoria, lo que lleva a la reflexión sobre lo que realmente se considera Transferencia de valores y lo que ha sido evaluado por las distintas comisiones, acentuando inevitablemente la brecha de género, también en la Transferencia de Conocimiento. El análisis de los resultados permite obtener algunas conclusiones relevantes sobre los posibles fallos que ha tenido esta primera convocatoria durante todo el proceso, desde la emisión de la convocatoria hasta la resolución de las solicitudes, con propuestas de mejora para las siguientes.[EN] In 2018, the Ministry of Science, Innovation and Universities convened the new Transfer of Knowledge and Innovation six year term. More than a year later, ANECA publishes the results in which more than half of the applications had not met the requirements for that six-year term to be granted. From the analysis of the results of a survey carried out by the Association of Women Researchers and Technologists, it is highlighted that the applications evaluated successfully had a higher percentage of contributions based on the Transfer that generates economic value, while the applications evaluated negatively had a higher percentage of contributions based on the Transfer that generates social value. This result seems to explain the higher percentage of successful male researchers in contrast to successful female researchers in this call. This result leads to reflection on what is really considered Transfer of values and what has been evaluated by the different commissions, inevitably accentuating the gap gender, also in Knowledge Transfer. The analysis of the results allows to conclude on the possible failures that this first call has had during the whole process, from the launching of the call to the resolution of the applications, and this paper suggests proposals for improvement for the following calls.Asociación de Mujeres Investigadoras y Tecnólogas (AMIT)López Díaz, AJ.; Pereira, MD. (2021). Transferencia del conocimiento: ¿una cuestión de género?. https://doi.org/10.4995/citecma.2021.14261OJSANECA (2020). ¿Qué estamos haciendo en ANECA en relación con el género? http://www.aneca.es/Sala-de-prensa/Noticias/2020/Que-estamos-haciendo-en-ANECA-en-relacion-con-el-genero [Consulta: 25 de Julio, 2020]Best, Kathinka et al. (2016). "The gender dimension knowledge and technology transfer - the German case" en European Journal of Innovation Management, Vol. 19, No. 1, pp. 2-25. https://doi.org/10.1108/EJIM-07-2015-0052Carreiro, María y López, Cándido (2020) "Las mujeres y la transferencia del conocimiento." en Tribuna Feminista https://tribunafeminista.elplural.com/2020/07/las-mujeres-y-la-transferencia-del-conocimiento/[Consulta: 30 de Julio, 2020]Connell, Raewyn. (2005). "Masculinities ", 2nd ed., Crows Nest, N.S.W, Allen & Unwin, Crows Nest, N.S.W.CRUE (2018). Transferencia del Conocimiento: nuevo modelo para su prestigio e impulso. http://www.crue.org/Documentos%20compartidos/Publicaciones/Transferencia%20del%20Conocimiento/2018.11.28-Transferencia%20del%20Conocimiento%20DEFINITIVO_completo%20digital.pdf [Consulta: 29 de Junio, 2020]Dasgupta, Nilanjana y Stout, Jane G. (2014). "Girls and Women in Science, Technology, Engineering, and Mathematics: STEMing the Tide and Broadening Participation in STEM Careers" en Policy Insights from the Behavioral and Brain Sciences, Vol. 1, No.1, pp. 21-29. https://doi.org/10.1177/2372732214549471European Commission (2019) She Figures 2018 Publications Office of the European Union, Luxembourg.https://ec.europa.eu/info/publications/she-figures-2018_en [Consulta: 25 de Julio, 2020]Franklin, Neil (2019). The a lack of female role models in STEM. https://workplaceinsight.net/the-lack-of-female-role-models-in-stem/ [Consulta: 25 de Julio, 2020]Gabster, Brooke Peterson et al. (2020, June 27). "Challenges for the female academic during the COVID-19 pandemic" en The Lancet, Vol. 395, pp. 1968-1970. https://doi.org/10.1016/S0140-6736(20)31412-4Klofsten, Magnus and Jones-Evans, Dylan (2000). "Comparing academic entrepreneurship in Europe- the case of Sweden and Ireland" en Small Business Economics, 2000, Vol. 14, No. 4, pp. 299-309. https://doi.org/10.1023/A:1008184601282Lerchenmueller, March J., Sorenson, Olav & Jena, Anupam B. (2019). "Gender differences in how scientists present the importance of their research: Observational study" en BMJ 2019;367:l6573 . https://doi.org/10.1136/bmj.l6573López Díaz, Ana de Jesús (2013). "Emprender: una perspectiva de género". https://dialnet.unirioja.es/servlet/libro?codigo=567952 [Consulta: 30 de Julio, 2020]Observatorio Mujeres, Ciencia e Innovación (2020). Mujeres e innovación 2020. https://www.ciencia.gob.es/stfls/MICINN/Ministerio/FICHEROS/Publicaciones/AF_Mujeres-e-innovacion_web.pdf [Consulta: 29 de Junio, 2020]OECD (2015), Frascati Manual 2015: Guidelines for Collecting and Reporting Data on Research and Experimental Development, The Measurement of Scientific, Technological and Innovation Activities, OECD Publishing, Paris. https://doi.org/10.1787/9789264239012-enPalmén, Rachel et al. (2020). "Integrating the Gender Dimension in Teaching, Research Content & Knowledge and Technology Transfer: Validating the EFFORTI Evaluation, Framework through three Case Studies in Europe" en Evaluation and Program Planning, Vol. 79, 101751. https://doi.org/10.1016/j.evalprogplan.2019.101751Pereira, Dolores (2014). "Improving female participation in professional engineering geology to bring new perspectives on ethics." en International Journal of Environmental Research and Public Health, 2014, Vol. 11, No. 9, pp. 9429- 9445. https://doi.org/10.3390/ijerph110909429Schein, Edgar H. (1990). "Organizational culture" en American Psychologist, Vol. 45, No. 2, pp. 109-119. https://doi.org/10.1037/0003-066X.45.2.109Schein, Edgar H. (2010). Organizational Culture and Leeadership, The Jossey-Bass Business & Management Series, 4th ed., Jossey-Bass, San Francisco, CA.Vaquero García, Alberto et al. (2012) "La mujer en el campo científico, tecnológico y transferencia del conocimiento en Galicia: situación actual y actuaciones futuras. http://hdl.handle.net/2183/16647 [Consulta: 30 de Julio, 2020]Zachmann, Karl. (2018). Women in STEM: Female Role Models and Gender Equitable Teaching Strategies. Retrieved from Sophia, the St. Catherine University repository website: https://sophia.stkate.edu/maed/272 [Consulta: 25 de Julio, 2020
Design and test of cryogenic cold plate for thermal-vacuum testing of space components
This paper proposes a novel cryogenic fluid cold plate designed for the testing of cryogenic space components. The cold plate is able to achieve cryogenic temperature operation down to -196 °C with a low liquid nitrogen (LN2) consumption. A good tradeoff between high rigidity and low thermal conduction is achieved thanks to a hexapod configuration, which is formed by six hinge-axle-hole articulations in which each linking rod bears only axial loads. Thus, there is not any stress concentration, which reduces the diameter of rod sections and reduces the rods' thermal conduction. This novel design has a unique set of the following properties: Simple construction, low thermal conduction, high thermal inertia, lack of vibrational noise when cooling, isostatic structural behavior, high natural frequency response, adjustable position, vacuum-suitability, reliability, and non-magnetic. Additionally, the presented cold plate design is low-cost and can be easily replicated. Experimental tests showed that a temperature of at least -190 °C can be reached on the top surface of the cold plate with an LN2 consumption of 10 liters and a minimum vibration frequency of 115 Hz, which is high enough for most vibration tests of space components.The research leading to these results received funding from the Spanish Ministerio de Economía y Competitividad inside the Plan Estatal de I+D+I 2013-2016 under grant agreement n° ESP2015-72458-EXP.
The authors wish to recognize the work of Alba Martínez Pérez in the preparation of figures, the work of Miguel Fernández Muñoz in 3D model preparation, and the assistance of Hector Cruz Rosco during thermal and dynamic tests. The authors especially wish to recognize the work of Jorge Serena de Olano in CNC manufacturing
Unibertsitate graduak: berrikuntzarako aukerak eta bideak
[ES]Este libro recoge un total de 14 Proyectos de Innovación Educativa de la UPV/EHU de la convocatoria 2008/10 y desarrollados a lo largo de esos cursos académicos. En la citada convocatoria se presentaron 55 proyectos, siendo finalmente admitidos 37, participando en los mismos un total de 200 docentes. En este libro se presenta una selección con los proyectos que obtuvieron los resultados más destacados, siendo clasificados en cuatro apartados: I) Aprendizaje cooperativo y aprendizaje colaborativo, II) Método de caso, aprendizaje basado en problemas y aprendizaje basado en proyectos, III) Utilización de las TIC y desarrollo de competencias digitales, y IV) Contrato de aprendizaje y evaluación. El libro además recoge el prólogo y un artículo sobre los grados universitarios elaborados por miembros del Servicio de Asesoramiento Educativo (SAE/HELAZ): Tal y como señala el título del libro, los grados universitarios son posibilidades y caminos de innovación. El libro electrónico se alojará en la página web del SAE/HELAZ en el apartado correspondiente al os proyectos de innovación educativa (PIE).[EU] Liburu honetan 2008/10 deialdiko UPV/EHUren Hezkuntza Berrikuntzarako 14 proiektu jaso dira, ikasturte horietan garatu zirenak. Deialdi horretan aurkeztu ziren 55 proiektuetatik 37 onartu ziren eta horietan 200 irakaslek parte hartu zuten. Liburu honek emaitzarik esanguratsuenak lortu zituzten proiektuak ekarri ditu, lau ataletan banatuta: I) Ikaskuntza kooperatiboa eta elkarlaneko ikaskuntza, II) Kasu metodoa, problema eta proiektuetan oinarritutako ikaskuntza, III) IKT-en erabilera eta gaitasun digitalen garapena, eta IV) Ikaskuntza kontratua eta ebaluazioa., Horrez gain, liburuan Hezkuntzarako Laguntza Zerbitzuaren (SAE/HELAZ) zenbait kidek idatzi dituzten unibertsitate graduei buruzko atarikoa eta artikulu bat ere badaude: Liburuaren izenburuan adierazi den ildoan, unibertsitate graduak berrikuntzarako aukerak eta bideak dira. Liburu elektronikoa SAE/HELAZeko webgunean jarriko da Hezkuntza Berrikuntzarako Proiektuei (HBP) dagokien atalean
Behaviour of Non-O157 STEC and Atypical EPEC during the Manufacturing and Ripening of Raw Milk Cheese
12 p.This study was carried out to assess the survival of Shiga toxin-producing E. coli (STEC) and atypical enteropathogenic Escherichia coli (aEPEC) during the traditional manufacturing and ripening of Spanish hard cheese from raw cow’s milk. Milk samples were spiked with up to 3.1–3.5 log cfu/mL of one strain of STEC (O140:H32 serotype) and one of aEPEC (serotype O25:H2). The first steps of cheesemaking allow for a STEC and aEPEC increase of more than 1 log cfu/mL (up to 4.74 log cfu/g and 4.55 log cfu/g, respectively). After cheese pressing, a steady reduction of both populations was observed, with the STEC strain being more sensitive. The studied pathogenic E. coli populations decreased by 1.32 log cfu/g in STEC and 0.59 log cfu/g in aEPEC in cheese ripened during a minimum period of 60 d. Therefore, a moderate contamination by these diarrhoeagenic E.
coli pathotypes, in particular, with aEPEC, on cheese manufactured from raw milk may not be totally controlled through the cheesemaking process and during a maturation of 90 d. These findings remark the importance of improvement in bacteriological quality of raw milk and crosscontamination prevention with diarrhoeagenic E. coli in the dairy industryS
A comparative study of boron transport models in NRC thermal-hydraulic code TRACE
[EN] Recently, the interest in the study of various types of transients involving changes in the boron concentration inside the reactor, has led to an increase in the interest of developing and studying new models and tools that allow a correct study of boron transport. Therefore, a significant variety of different boron transport models and spatial difference schemes are available in the thermal-hydraulic codes. According to this interest, in this work it will be compared the results obtained using the different boron transport models implemented in the NRC thermal-hydraulic code TRACE. To do this, a set of models has been created using the different options and configurations that could have influence in boron transport. These models allow us to reproduce a simple event of filling or emptying the boron concentration in a long pipe. Moreover, with the aim to compare the differences obtained when one-dimensional or three-dimensional components are chosen, it has modeled many different cases using only pipe components or a mix of pipe and vessel components. In addition, the influence of the void fraction in the boron transport has been studied and compared under close conditions to a BWR commercial model. A final collection of the different cases and boron transport models are compared between them and those corresponding to the analytical solution provided by the Burgers equation. From this comparison, important conclusions are drawn that will be the basis of modeling the boron transport in TRACE adequately.Olmo-Juan, N.; Barrachina Celda, TM.; Miró Herrero, R.; Verdú Martín, GJ.; Pereira, C. (2019). A comparative study of boron transport models in NRC thermal-hydraulic code TRACE. Brazilian Journal of Radiation Sciences. 7(2B):1-18. https://doi.org/10.15392/bjrs.v7i2B.767S11872
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