Thermal influence of welding process on strength overmatching of thin dissimilar sheets joints

The investigation addresses the overall performance of black and white joints (BWJ) of low carbon steel and stainless steel thin sheets achieved by laser hybrid welding. First, thermal field modelling is carried out by considering Goldak’s double ellipsoidal heat source model, together with a contribution of the authors related to the shape coefficients. In parallel, the technological development of BWJ laser hybrid welding is also addressed. Material characterisation by means of macro and microstructural examination and hardness tests is performed. The overall tensile performance of BWJ is discussed together with the weld metal strength overmatching. The tensile tests results indicate that in case of transversally loaded joints, the positive difference in yield between the weld metal and the base materials protects the weld metal from being plastically deformed; the flat transverse tensile specimens loading up to failure reveals large strains in low carbon steel, far away from the wel

Comunicación, factor clave en la organización de eventos exitosos.

72 páginas incluye ilustraciones y diagramasLa organización de eventos es un campo que viene desarrollándose con mucha fuerza como aspecto estratégico en los planes de comunicación en las organizaciones de diferente tipo. Este trabajo pretende ser un aporte para los comunicadores en el camino de la organización de eventos exitosos que respondan a las necesidades de las empresas. Esta es una investigación aplicada a cuatro eventos, considerados exitosos, realizados en el año 2012 en la ciudad de Bogotá, Colombia, con el fin de entender y explicar cuál es el rol que cumple la comunicación en la realización de un evento. Con esta investigación se identifican las estrategias de comunicación en los eventos seleccionados: Gastronomía, Festival Iberoamericano de Teatro, Campus Party Colombia y la Conferencia Internacional de la Palma de Aceite

Determination of the hoop fracture properties of unirradiated hydrogen-charged nuclear fuel cladding from ring compression tests

In this work, a new methodology is devised to obtain the fracture properties of nuclear fuel cladding in the hoop direction. The proposed method combines ring compression tests and a finite element method that includes a damage model based on cohesive crack theory, applied to unirradiated hydrogen-charged ZIRLOTM nuclear fuel cladding. Samples with hydrogen concentrations from 0 to 2000 ppm were tested at 20 �C. Agreement between the finite element simulations and the experimental results is excellent in all cases. The parameters of the cohesive crack model are obtained from the simulations, with the fracture energy and fracture toughness being calculated in turn. The evolution of fracture toughness in the hoop direction with the hydrogen concentration (up to 2000 ppm) is reported for the first time for ZIRLOTM cladding. Additionally, the fracture micromechanisms are examined as a function of the hydrogen concentration. In the as-received samples, the micromechanism is the nucleation, growth and coalescence of voids, whereas in the samples with 2000 ppm, a combination of cuasicleavage and plastic deformation, along with secondary microcracking is observed

Estudio del Comportamiento en Fractura de Vainas de Combustible Nuclear fragilizadas por Hidruros

En este artículo se ha estudiado, mediante el ensayo de compresión diametral (RCT), el comportamiento mecánico y en rotura de vainas de combustible nuclear de ZIRLO TM hidruradas. El hidrógeno se introdujo en las muestras mediante carga catódica y se precipitó en forma de hidruros circunferenciales mediante un tratamiento térmico. Los ensayos de compresión diametral se realizaron para concentraciones de hidrógeno de 150 a 2000 ppm. Los resultados experimentales obtenidos muestran que este ensayo es particularmente útil para el estudio del comportamiento en fractura de las vainas. Con este fin, se desarrolló un modelo de elementos finitos en el que se implemento la teoría de la fisura cohesiva. Aplicando dicho modelo se ha logrado calcular la energía de fractura de las vainas de combustible nuclear en dirección circunferencial para los distintos contenidos de hidrógeno estudiados a partir de los registros experimentales carga-desplazamiento del ensay

Breeding Strategies for Weather Resilience in Small Ruminants in Atlantic and Mediterranean Climates

Many efforts are being made to cope with negative consequences of climate change (CC) on livestock. Among them, selective breeding of resilient animals to CC is presented as an opportunity to maintain high levels of performance regardless of variation in weather. In the present work, we proposed a set of breeding strategies to improve weather resilience in dairy goats raised in north-western European Atlantic conditions and dairy sheep raised in Mediterranean conditions while improving production efficiency at the same time. Breeding strategies differed in the selection emphasis placed on resilience traits, ranging from 0 to 40% in the index. Simulations were carried out mimicking real breeding programs including: milk yield, length of productive life, age at first kidding and mastitis incidence in dairy goats and milk, fat and protein yields, and fertility for dairy sheep. Considering the particular climatic conditions in the two regions, the predicted future climate scenarios, and genetic correlations among breeding objectives, resilience was defined as stability to weather changes for dairy goats and as the ability to improve performance under heat stress for dairy sheep. A strategy giving a selection weight of 10 and 20% for goat and sheep resilience, respectively, resulted in the best overall genetic response in terms of both, production and resilience ability. Not considering resilience in breeding programs could lead to a major production loss in future climate scenarios, whereas putting too much emphasis on resilience would result in a limited progress in milk production

Development and evaluation of a search filter to identify prognostic factor studies in Ovid MEDLINE

Background: Systematic reviews (SRs) are valuable resources as they address specific clinical questions by summarizing all existing relevant studies. However, finding all information to include in systematic reviews can be challenging. Methodological search filters have been developed to find articles related to specific clinical questions. To our knowledge, no filter exists for finding studies on the role of prognostic factor (PF). We aimed to develop and evaluate a search filter to identify PF studies in Ovid MEDLINE that has maximum sensitivity. Methods: We followed current recommendations for the development of a search filter by first identifying a reference set of PF studies included in relevant systematic reviews on the topic, and by selecting search terms using a word frequency analysis complemented with an expert panel discussion. We evaluated filter performance using the relative recall methodology. Result: We constructed a reference set of 73 studies included in six systematic reviews from a larger sample. After completing a word frequency analysis using the reference set studies, we compiled a list of 80 of the frequent methodological terms. This list of terms was evaluated by the Delphi panel for inclusion in the filter, resulting in a final set of 8 appropriate terms. The consecutive connection of these terms with the Boolean operator OR produced the filter. We then evaluated the filter using the relative recall method against the reference set, comparing the references included in the SRs with our new search using the filter. The overall sensitivity of the filter was calculated to be 95%, while the overall specificity was 41%. The precision of the filter varied considerably, ranging from 0.36 to 17%. The NNR (number needed to read) value varied largely from 6 to 278. The time saved by using the filter ranged from 13–70%. Conclusions: We developed a search filter for OVID-Medline with acceptable performance that could be used in systematic reviews of PF studies. Using this filter could save as much as 40% of the title and abstract screening task. The specificity of the filter could be improved by defining additional terms to be included, although it is important to evaluate any modification to guarantee the filter is still highly sensitive

Generadores de valor del proceso logístico de las empresas floricultoras de Cundinamarca

An organization requires supplying goods and services to customers, when, how and where they require them; This is achieved through valuable activities, framed within the logistics process. In this context, this research emerged, with the purpose of determining what are the elements that drive value in the activities of the logistics process of companies in the floriculture sector of the department of Cundinamarca. The study was classified as descriptive, non-experimental and cross-sectional. The information was collected through two questionnaires, one for internal clients of the logistics process and another for workers in the logistics area. Reliability was obtained through the Cronbach's Alpha method and the resulting values for the applied questionnaires were: clients of 0.797 and logistics workers of 0.877; which are highly reliable. Once the instruments were applied and analyzed, it was evident that most of the factors that generate value in the activities of the logistics process are coincident among the populations studied and are related to the theoretical bases used. It is concluded that the success of an organization is not only a logical consequence of performing well the operational support actions, but also it is necessary to generate value in each activity of the company to satisfy the requirements of the clients and maintain them over time.Una organización requiere suministrar bienes y servicios a los clientes, cuándo, cómo y dónde los requieran; ello se logra, por medio de actividades de valor, enmarcadas dentro del proceso logístico. Bajo este contexto surgió la presente investigación, con el propósito de determinar cuáles son los elementos que impulsan el valor en las actividades del proceso logístico de las empresas del sector floricultor del departamento de Cundinamarca. El estudio se tipificó como descriptivo, no experimental y transversal. La información fue recolectada a través de dos cuestionarios, uno para los clientes internos del proceso logístico y otro para los trabajadores del área logística. La confiabilidad se obtuvo a través del método Alfa de Cronbach y los valores resultantes para los cuestionarios aplicados fueron: clientes de 0.797 y trabajadores logísticos de 0.877; los cuales son altamente confiables. Una vez aplicados y analizados los instrumentos, se evidenció que la mayoría de los factores que generan valor en las actividades del proceso logístico son coincidentes entre las poblaciones estudiadas y conservan relación con las bases teóricas utilizadas. Se concluye que el éxito de una organización no solo es consecuencia lógica de realizar bien las acciones operativas de apoyo, sino que además es necesario generar valor en cada actividad de la empresa para satisfacer los requerimientos de los clientes y mantenerlos en el tiempo

Procesamiento de papa criolla precocida y congelada mediante la técnica de congelación individual (iqf), en seis genotipos promisorios de papa criolla (solanum phureja)

Se evaluó el comportamiento industrial de seis clones promisorios de papa criolla provenientes de hibridación interespecífica cultivados en tres localidades (Soacha, Duitama y Mosquera) en los procesos de papa precocida y congelada IQF (Individual Quick Freezing). Como testigo se utilizó la variedad común Yema de Huevo o “Clon 1”. Las variables evaluadas fueron: peso seco, gravedad específica, rendimiento en el proceso, numero de ojos por tubérculo, profundidad de los ojos y tipo de piel. Se encontró que la mayoría de las variables, a pesar de ser definidas por el genotipo, son afectadas por las  condiciones ambientales. Los tubérculos producidos en Marengo, presentaron bajos contenidos de materia seca, característica apropiada para la elaboración de papa precocida. El clon 98-71.26, presentó alto potencial para ser procesado en forma precocida, debido a sus bajaspérdidas en precocción y sus características organolépticas similares al “Clon 1”, adicionalmente presentó un alto valor heterótico para la variable rendimiento. En lapapa precocida y congelada la ausencia de defectos, el aroma y sabor y el color de la piel son los atributos más importantes. La papa precocida conservó sus características organolépticas iniciales por mas de seis meses de almacenamiento. A partir de las exigencias de los consumidores en los diferentes productos se debe priorizar la búsqueda, por parte de los fitomejoradores, de los atributos de calidad necesarios para el proceso de precocción, entre estos se destacan: tubérculos redondos y pequeños, con ojos superficiales, piel lisa, color característico a la papa criolla y bajo contenido de materia seca

Development and evaluation of a search filter to identify prognostic factor studies in Ovid MEDLINE.

Background: Systematic reviews (SRs) are valuable resources as they address specific clinical questions by summarizing all existing relevant studies. However, finding all information to include in systematic reviews can be challenging. Methodological search filters have been developed to find articles related to specific clinical questions. To our knowledge, no filter exists for finding studies on the role of prognostic factor (PF). We aimed to develop and evaluate a search filter to identify PF studies in Ovid MEDLINE that has maximum sensitivity. Methods: We followed current recommendations for the development of a search filter by first identifying a reference set of PF studies included in relevant systematic reviews on the topic, and by selecting search terms using a word frequency analysis complemented with an expert panel discussion. We evaluated filter performance using the relative recall methodology. Results: We constructed a reference set of 73 studies included in six systematic reviews from a larger sample. After completing a word frequency analysis using the reference set studies, we compiled a list of 80 of the frequent methodological terms. This list of terms was evaluated by the Delphi panel for inclusion in the filter, resulting in a final set of 8 appropriate terms. The consecutive connection of these terms with the Boolean operator OR produced the filter. We then evaluated the filter using the relative recall method against the reference set, comparing the references included in the SRs with our new search using the filter. The overall sensitivity of the filter was calculated to be 95%, while the overall specificity was 41%. The precision of the filter varied considerably, ranging from 0.36 to 17%. The NNR (number needed to read) value varied largely from 6 to 278. The time saved by using the filter ranged from 13–70%. Conclusions: We developed a search filter for OVID-Medline with acceptable performance that could be used in systematic reviews of PF studies. Using this filter could save as much as 40% of the title and abstract screening task. The specificity of the filter could be improved by defining additional terms to be included, although it is important to evaluate any modification to guarantee the filter is still highly sensitive.post-print1282 K

Understanding the seasonality of performance resilience to climate volatility in Mediterranean dairy sheep

11 Pág. Departamento de ​Mejora Genética AnimalAs future climate challenges become increasingly evident, enhancing performance resilience of farm animals may contribute to mitigation against adverse weather and seasonal variation, and underpin livestock farming sustainability. In the present study, we develop novel seasonal resilience phenotypes reflecting milk production changes to fluctuating weather. We evaluate the impact of calendar season (autumn, winter and spring) on animal performance resilience by analysing 420,534 milk records of 36,908 milking ewes of the Chios breed together with relevant meteorological data from eastern Mediterranean. We reveal substantial seasonal effects on resilience and significant heritable trait variation (h2 = 0.03-0.17). Resilience to cold weather (10 °C) of animals that start producing milk in spring was under different genetic control compared to autumn and winter as exemplified by negative genetic correlations (- 0.09 to - 0.27). Animal resilience to hot weather (25 °C) was partially under the same genetic control with genetic correlations between seasons ranging from 0.43 to 0.86. We report both favourable and antagonistic associations between animal resilience and lifetime milk production, depending on calendar season and the desirable direction of genetic selection. Concluding, we emphasise on seasonal adaptation of animals to climate and the need to incorporate the novel seasonal traits in future selective breeding programmes.The work was mainly funded by iSAGE Horizon 2020 project: “Innovation for Sustainable Sheep and Goat Production in Europe” (679302; https://www.isage.eu/). Additional support was received by the UK Biotechnology and Biological Sciences Research Council ISP3 (BBS/E/D/30002275) and the Rural & Environment Science & Analytical Services (RESAS) Division of the Scottish Government.Peer reviewe