A New Classification System for Evaluating Patients with Severe Trauma Using B-type Natriuretic Peptide Levels and Estimated Glomerular Filtration Rate

Current systems for the evaluation of trauma severity are tedious and difficult to apply in an actual emergency setting. We aimed to develop and assess the accuracy of a more efficient severity evaluation system, termed the Ugawa classification, using brain-type natriuretic peptide (BNP) measurement and the estimated glomerular filtration rate (eGFR). Two-hundred trauma patients were divided into 2 groups using an eGFR cut-off value of 90ml/min/1.73m2 as an indicator of normal renal function and 2 additional groups according to whether the BNP values were greater or less than the age in years. This resulted in 4 subject groups with different combinations of eGFR and BNP. The mean SOFA score, injury severity scores (ISS), trauma and injury severity scores (TRISS), and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores of the groups were compared by Kruskal-Wallis test, and the mortality rate after 90 days was calculated. Significant intergroup differences were found in SOFA scores, ISS scores, and APACHE II-predicted mortality rates. Although no significant differences were found in the mortality rate after 90 days or TRISS-predicted mortality rate among the 4 groups, there was a trend toward increasing trauma severity from group 1 to 4. Thus, the Ugawa classification is as accurate as existing systems, has greater efficiency, and is user-friendly

Timber-Strong Design Build Senior Project

The 2019 Timber-Strong Design Build Competition was developed by the American Wood Council, Simpson Strong-Tie Company Inc, and APA - The Engineered Wood Association to cultivate timber design, building, and sustainability experience for students. Participating students gained exposure to performance analysis, construction management, building practices, and project bid preparation while practicing as a design construction firm. In the process of this hands-on experience, students were expected to procure all building materials and tools themselves. The Timber Strong senior project consisted of participating in the Timber-Strong competition, then re-purposing the structure for use as a playhouse in a pre-school. The intent of the project was to explore sustainability options after finishing the competition, allowing the students to experience hands-on construction, marketing, professional communication, and a realistic interdisciplinary process

Modelling of friction stir welding of DH36 steel

A 3-D computational fluid dynamics (CFD) model was developed to simulate the friction stir welding of 6-mm plates of DH36 steel in an Eulerian steady-state framework. The viscosity of steel plate was represented as a non- Newtonian fluid using a flow stress function. The PCBN-WRe hybrid tool was modelled in a fully sticking condition with the cooling system effectively represented as a negative heat flux. The model predicted the temperature distribution in the stirred zone (SZ) for six welding speeds including low, intermediate and high welding speeds. The results showed higher asymmetry in temperature for high welding speeds. Thermocouple data for the high welding speed sample showed good agreement with the CFD model result. The CFD model results were also validated and compared against previous work carried out on the same steel grade. The CFD model also predicted defects such as wormholes and voids which occurred mainly on the advancing side and are originated due to the local pressure distribution between the advancing and retreating sides. These defects were found to be mainly coming from the lack in material flow which resulted from a stagnant zone formation especially at high tra- verse speeds. Shear stress on the tool surface was found to in- crease with increasing tool traverse speed. To produce a “sound” weld, the model showed that the welding speed should remain between 100 and 350 mm/min. Moreover, to prevent local melt- ing, the maximum tool’s rotational speed should not exceed 550 RPM

Defects in Friction Stir Welding of Steel

Defects associated with friction stir welding of two steel grades including DH36 and EH46 were investigated. Different welding parameters including tool rotational and tool traverse (linear) speeds were applied to understand their effect on weld seam defects including microcracks and voids formation. SEM images and infinite focus microscopy were employed to identify the defects types. Two new defects associated with the friction stir welding process are introduced in this work. The first defect identified in this work is a microcrack found between the plunge and the steady state region and attributed to the traverse moving of the tool with unsuitable speed from the plunge-dwell to the steady state stage. The tool traverse speed has recommended to travel 20 mm more with accelerated velocity range of 0.1 from the maximum traverse speed until reaching the steady state. The maximum recommended traverse speed in the steady state was also suggested to be less than 400 mm/min in order to avoid the lack in material flow. The second type of defect observed in this work was microcracks inside the stirred zone caused by elemental precipitations of TiN. The precipitates of TiN were attributed to the high tool rotational speed which caused the peak temperature to exceed 1200 °C at the top of the stirred zone and based on previous work. The limit of tool rotational speed was recommended to be maintained in the range of 200-500 RPM based on the mechanical experiments on the FSW samples