43 research outputs found
Predicting filling efficiency of composite resin injection repair
We propose to develop a two-dimensional reduced-order reconstruction, simulation and injection strategy to model resin injection repair which is scalable and practical for use with available equipment. The proposed method involves reconstructing a damaged composite laminate using ultrasonic C-scans to determine the damage zone geometry and porosity. The damage zone permeability is calculated via semi-empirical constitutive equations, and used as input data for the CFD simulation of a resin injection process through the composite. The ultimate aim is to guide repair operators by identifying suitable injection configurations in order to improve cavity filling and thus repair efficiency. After establishing the methodology basis, we verify simulations through comparison to a proposed and analytically solved problem. Validation results show a 70+% simulation accuracy. Finally, we create a case study where cavity filling is improved by applying knowledge of the damage zone. This method's ability to predict filling efficacy offers a viable, quantitative and more consistent alternative to existing intuition-based practices for resin injection repair
Determination of composition and structure of spongy bone tissue in human head of femur by Raman spectral mapping
Biomechanical properties of bone depend on the composition and organization of collagen fibers. In this study, Raman microspectroscopy was employed to determine the content of mineral and organic constituents and orientation of collagen fibers in spongy bone in the human head of femur at the microstructural level. Changes in composition and structure of trabecula were illustrated using Raman spectral mapping. The polarized Raman spectra permit separate analysis of local variations in orientation and composition. The ratios of ν2PO43−/Amide III, ν4PO43−/Amide III and ν1CO32−/ν2PO43− are used to describe relative amounts of spongy bone components. The ν1PO43−/Amide I ratio is quite susceptible to orientation effect and brings information on collagen fibers orientation. The results presented illustrate the versatility of the Raman method in the study of bone tissue. The study permits better understanding of bone physiology and evaluation of the biomechanical properties of bone
Resilient cooling strategies – A critical review and qualitative assessment
The global effects of climate change will increase the frequency and intensity of extreme events such as heatwaves and power outages, which have consequences for buildings and their cooling systems. Buildings and their cooling systems should be designed and operated to be resilient under such events to protect occupants from potentially dangerous indoor thermal conditions. This study performed a critical review on the state-of-the-art of cooling strategies, with special attention to their performance under heatwaves and power outages. We proposed a definition of resilient cooling and described four criteria for resilience—absorptive capacity, adaptive capacity, restorative capacity, and recovery speed —and used them to qualitatively evaluate the resilience of each strategy. The literature review and qualitative analyses show that to attain resilient cooling, the four resilience criteria should be considered in the design phase of a building or during the planning of retrofits. The building and relevant cooling system characteristics should be considered simultaneously to withstand extreme events. A combination of strategies with different resilience capacities, such as a passive envelope strategy coupled with a low-energy space-cooling solution, may be needed to obtain resilient cooling. Finally, a further direction for a quantitative assessment approach has been pointed out
How can Asphalt Roads Extend the Range of In Situ Polarized Light Pollution? A Complex Ecological Trap of Ephemera danica and a Possible Remedy
Evaluating english language teaching software for kids: Education or entertainment or both?
The purpose of this study is to offer a critical consideration of instructional software designed particularly for children. Since the early 1990s computer applications integrating education with entertainment have been adopted on a large scale by both educators and parents. It is expected that through edutainment software the process of learning is going to be colorful and fun and that learners can acquire information without work and serious study. The aim of this article is to draw attention to possible harmful effects of this wholesale adoption of edutainment software, particularly to introducing learning "as a bitter medicine that needs the sugar-coating of entertainment to become palatable" (Resnick, 2004). It argues that it may be time to examine critically the educational potential of such software together with the advantages and disadvantages it might bring to the instructional process. The discussion focuses, after a brief definition of edutainment, on five English language teaching software packages for kids which are randomly selected from the market. They are examined through McKenzie's (2000) Assessment Chart to see to what extent the implementation of edutainment software has been able to match their promises. The study calls for critical awareness of how instructional software is impacting education and at the same time for the engagement of teachers in exploring the computer applications that shape classroom learning and teaching. © The Turkish Online Journal of Educational Technology 2002
Art. 1.1475/ringraziamenti
Abstract. -OBJECTIVE: Studies in animals have provided key evidence that antagonizing TNF-α α is a viable therapeutic strategy for diffuse severe brain injury. This study is planned to prevent post-traumatic secondary tissue damages in rat diffuse severe brain injury model, which is induced by alone or combined administration of Etanercept and lithium chloride (LiCl). MATERIALS AND METHODS: Male SpragueDawley rats were used in the current study. Rats were divided into 5 groups. Trauma was not induced and treatment was not applied to rats of Sham group. For rats of Trauma+Saline group, saline 0.9% was administered via intraperitoneal (i.p.) route at dose of 1 mg/100 g body weight 1 hour after trauma. For rats of Trauma+Etanercept group, Etanercept was administered via i.p. route at dose of 5 mg/kg body weight 1 hour after trauma. For rats of Trauma+LiCl group, LiCl was administered via i.p. route at dose of 50 mg/kg body weight 1 hour after trauma. For rats of Etanercept+LiCl group, Etanercept and LiCl were administered via i.p. route at dose of 5 mg/kg body weight and 50 mg/kg body weight, respectively, 1 hour after trauma. Serum glial fibrillary acidic protein (GFAP) and Tau levels were analyzed with ELISA. For analyses H&E, TUNEL, GFAP and TNF-α α staining methods were used. RESULTS: We demonstrate that Etanercept treatment reduced the TBI-induced brain tissues alteration, reduced the expression of TNF-α α and improve edema and axonal swelling. We observed a significant decrease in TNF-α α and GFAP positivity after LiCl was administered. CONCLUSIONS: The findings obtained in this study suggest that the combination therapy with Etanercept and LiCl decreased neurona