Talleres de resolución de problemas vivenciales para las habilidades matemáticas en estudiantes de bachillerato de una Institución Educativa Balzar, 2023

El objetivo general del estudio fue determinar si los talleres de resolución de problemas vivenciales desarrollan las habilidades matemáticas en estudiantes de bachillerato de una Institución Educativa Balzar, 2023. El estudio fue de tipo aplicado, de enfoque cuantitativo, de nivel explicativo, de diseño experimental, de alcance preexperimental. La muestra estuvo conformada por 10 estudiantes. Los resultados evidencian que existe un valor sig.=,018<5%, en este sentido, se concluye que ha mejorado la dimensión algebra y funciones de los estudiantes con el programa aplicado y basado en la resolución de problemas vivenciales. Así mismo, se encontró que existe un valor sig.=,015<5%; donde se concluye que ha mejorado la dimensión geometría media de los estudiantes con el programa aplicado y basado en la resolución de problemas vivenciales. De igual manera, existe un valor sig.=,021<5%; donde, se concluye que ha mejorado la dimensión estadística y probabilidad de los estudiantes con el programa aplicado y basado en la resolución de problemas vivenciales. Se concluye que con un valor sig.=,023<5%, ha mejorado el desarrollo de las habilidades matemáticas de los estudiantes con el programa aplicado y basado en la resolución de problemas vivenciales

Analysis of a Motocross Knee Brace: From the Real Model to the Numerical Finite Element Model via 3D Scanning and Reverse Engineering

Featured Application: This study outlines a novel procedure for the Finite Element Modelling and Analysis of motocross knee braces under race conditions. The aim is to quantitatively evaluate the effectiveness of such stabilisers in reducing the risk and consequences of musculoskeletal injuries, considering the current lack of industrial standards and dedicated scientific research works. Musculoskeletal injuries often occur when performing motocross; almost half of the overall ligamentous injuries (42%) are knee ligaments injuries. Lesions can be greatly reduced with knee braces. Commercial knee braces are expected to oppose and limit unwanted and potentially harmful movements such as hyperextension and excessive rotation of the knee joint. However, this aspect has not been fully investigated from a biomechanical point of view. This would require proper Finite Element Modelling (FEM) and Analysis (FEA). However, to perform FEA and evaluate the efficacy of the brace simulating sportive conditions, numerical models need to be built. It requires a dedicated setup and several preprocessing steps, for which no industrial standard or widely accepted better practise is available as of today. Firstly, the brace and the lower limb are scanned using a 3D scanner. The geometry is reconstructed using reverse engineering techniques. These allow us to obtain a smooth, reliable 3D model starting from the points cloud acquired during scanning. A lower limb model was created using a mixed approach, combining MRI data and 3D scanning. Finally, a simulation of the impact condition after a jump using the developed model was carried out

Weather radar for urban hydrological applications: lessons learnt and research needs identified from 4 pilot catchments in North-West Europe

International audienceThis study investigates the impact of rainfall estimates of different spatial resolutions on the hydraulic outputs of the models of four of the EU RainGain project’s pilot locations (the Cranbrook catchment (UK), the Herent catchment (Belgium), the Morée-Sausset catchment (France) and the Kralingen District (The Netherlands)). Two storm events, one convective and one stratiform, measured by a polarimetric X-band radar located in Cabauw (The Netherlands) were selected for analysis. The original radar estimates, at 100 m and 1 min resolutions, were aggregated to a spatial resolution of 1000 m. These estimates were then applied to the high-resolution semi-distributed hydraulic models of the four urban catchments, all of which have similar size (between 5 and 8 km2), but different morphological, hydrological and hydraulic characteristics. When doing so, methodologies for standardising rainfall inputs and making results comparable were implemented. The response of the different catchments to rainfall inputs of varying spatial resolution is analysed in the light of model configuration, catchment and storm characteristics. Rather surprisingly, the results show that for the two events under consideration the spatial resolution (i.e. 100 m vs 1000 m) of rainfall inputs does not have a significant influence on the outputs of urban drainage models. The present study will soon be extended to more storms as well as model structures and resolutions, with the final aim of identifying critical spatial-temporal resolutions for urban catchment modelling in relation to catchment and storm event characteristics

Mechanical Properties of Animal Tendons: A Review and Comparative Study for the Identification of the Most Suitable Human Tendon Surrogates

The mechanical response of a tendon to load is strictly related to its complex and highly organized hierarchical structure, which ranges from the nano-to macroscale. In a broader context, the mechanical properties of tendons during tensile tests are affected by several distinct factors, due in part to tendon nature (anatomical site, age, training, injury, etc.) but also depending on the experimental setup and settings. This work aimed to present a systematic review of the mechanical properties of tendons reported in the scientific literature by considering different anatomical regions in humans and several animal species (horse, cow, swine, sheep, rabbit, dog, rat, mouse, and foal). This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. The literature research was conducted via Google Scholar, PubMed, PicoPolito (Politecnico di Torino’s online catalogue), and Science Direct. Sixty studies were selected and analyzed. The structural and mechanical properties described in different animal species were reported and summarized in tables. Only the results from studies reporting the strain rate parameter were considered for the comparison with human tendons, as they were deemed more reliable. Our findings showed similarities between animal and human tendons that should be considered in biomechanical evaluation. An additional analysis of the effects of different strain rates showed the influence of this parameter

Finite element analysis of the flexor digitorum profundus tendon during a passive rehabilitation protocol

The present study aims to create a patient-specific hand model to simulate the passive rehabilitation on the index finger, quantifying the flexor digitorum profundus (FDP) tendon excursion and the stress experienced during simulated flexion. The computational model used in this analysis was created from an unknown patient dataset available in the Embodi3d online library. The segmentation, three-dimensional reconstruction, and modeling of the structures involved were performed using Materialise Mimics and Rhino3D. The FDP tendon excursion and stress values present in the model were calculated in the ANSYS environment. Based on the finite-element simulation, the FDP tendon presents an excursion of 10.1 mm during passive postoperative flexion. The highest-stress values were observed between the pulleys-FDP tendon contact surfaces. In particular, the pulley A1 exhibited the maximum principal stress of the model with a 58.7 MPa. The pulley A3 showed the same stress distribution pattern that A1 Pulley, but with the lowest values. The FDP Tendon excursion obtained is consistent with the results reported in the literature, which vary from 8 to 11 mm. The stress values found in the model explain the importance of the pulley mechanism keeping the FDP tendon attached to the finger bone during the range of motion experienced. The silico model proposed may potentially be used in the assessment of new medical device proposals in the field of hand reconstructive surgery

Evaluación técnica y económica del cultivo de caucho (Hevea brasilienses) clon FX 3864 bajo diferentes frecuencias de sangría y Estimulación

Anexo A. ubicación de area de estudio Anexo B. Formato de diagnosticoEste trabajo de investigación tuvo como propósito analizar el desempeño productivo y económico del clon de caucho natural (Hevea brasiliensis Willd. ex Adr. de Juss. Muell. Arg.) FX 3864 en diferentes frecuencias de sangría y con estimulación a base de Ethefon. El experimento se instaló en la Finca del Sr Itilio Durán en el municipio de Belén de los Andaquíes y en la finca La SIRINGA del municipio del El Paujil, departamento del Caquetá. El modelo experimental utilizado fue Diseño completamente al Azar, con cuatro repeticiones o bloques, cada bloque constó de cuatro tratamientos y cada tratamiento de 10 plantas, se aplicó el sistema de sangría 1/2S y dependiendo del tratamiento se le aplicó frecuencias de sangría d/3, d/4 o d/5, los árboles fueron estimulados con Ethefon al 2.5%, el estimulante fue aplicado sobre el sitio del corte sin sernambí. Las variables productivas estudiadas correspondieron a: Producción de látex líquido por sangría, producción de coagulo por sangría, porcentaje de sólidos en una muestra de coagulo húmedo, producción de caucho seco por sangría y contenido de sólidos en el látex de caucho (% DRC). Los datos obtenidos para las variables de Productividad fueron sometidos a análisis de varianza con prueba de comparación de medias de Tukey (P menor que 0.05%), obteniendo como resultado Belén de los Andaquíes como la mejor localidad para todas las variables, el T2: d/4, estimulado con Ethefon al 2.5% como el mejor tratamiento, mientras el menor valor lo presentó el T3: d/5 con estimulación al 2,5% quien evidenció los menores valores para la mayoría de variables exceptuando (DRC). Para el análisis económico de los indicadores de rentabilidad se determinaron los costos de producción por cada tratamiento. Concluido el trabajo se recomienda implementar el T2 (1/2S d/4 6d/7 ET 2,5% 4/y) teniendo en cuenta que presenta la mejor rentabilidad, oscilando entre el 52% y el 58% en las dos localidades

3d printing and testing of rose thorns or limpet teeth inspired anchor device for tendon tissue repair

Purposes: Advancements in medical technology have enabled medical specialists to resolve significant problems concerning tendon injuries. However, despite the latest improvements, surgical tendon repair remains challenging. This study aimed to explore the capabilities of the current state-of-the-art technologies for implantable devices. Methods: After performing extensive patent landscaping and literature review, an anchored tissue fixation device was deemed the most suitable candidate. This design was firstly investigated numerically, realizing a Finite Element Model of the device anchored to two swine tendons stumps, to simulate its application on a severed tendon. Two different hook designs, both bio-inspired, were tested while retaining the same device geometry and anchoring strategy. Then, the applicability of a 3D-printed prototype was tested on swine tendons. Finally, the device-tendon stumps ensemble was subjected to uniaxial tensile tests. Results: The results show that the investigated device enables a better load distribution during the immobilized limb period in comparison to standard suture-based approaches, yet it still presents several design flaws. Conclusions: The current implantable solutions do not ensure an optimal result in terms of strength recovery. This and other weak points of the currently available proposals will serve as a starting point for future works on bio-inspired implantable devices for tendon repair

Mechanical Stapling Devices for Soft Tissue Repair: A Review of Commercially Available Linear, Linear Cutting, and Circular Staplers

Stapling devices have emerged as a widespread and effective option for soft tissue surgery, offering promising outcomes for patients by reducing complication rates and surgery time. This review aims to provide an exhaustive analysis of commercially available alternatives in the market, incorporating insights from market analysis, patent landscape, and the existing literature. The main focus lies in identifying and evaluating the most widely adopted and innovative stapling devices, including linear, linear cutting, circular, and powered staplers. In addition, this review delves into the realm of bioabsorbable staples, exploring the materials utilized and the surgical fields where these advanced staples find applications. To facilitate easy comprehension, the gathered information is presented in tables, highlighting the essential parameters for each stapling device. This comprehensive research about stapling devices is intended to aid healthcare practitioners and researchers in making informed decisions when choosing the most appropriate instrument for specific surgical procedures