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Background: The selection of the best donor for each specific patient is crucial for the success of allogeneic hematopoietic stem cell transplantation (HSCT). However, there is debate on the choice of the best donor when multiple suitable donors exist. Methods: By using own data from two transplant centers, we have developed a calculator able to provide the patients' 2-year overall survival (OS) associated with each of the potential donor options during the selection process, in order to support the transplant physician during the choice. Data on 737 HSCTs with HLA-identical siblings, and unrelated or related haploidentical donors from January 2010 to July 2022 have been retrospectively obtained. Results: Patients' age, disease, comorbidity index, and donor type were found to be significant variables able to predict the outcome with robustness (concordance index: 0.677). Estimates are provided within an example in the text showing outcomes with four donor options for a specific patient. Conclusions: We present the prototype of a tool supporting the selection of the best donor, guiding transplant physicians during the delicate process of donor selection before HSCT. This approach relies on real data from the centers, reflecting their local clinical experience. Improvements are underway with a larger, ongoing multicenter study. [ABSTRACT FROM AUTHOR]

L-PBF is an additive manufacturing process forming parts with complex geometries by adding material layer by layer. The selection of the process parameters in L-PBF has a significant impact on the mechanical properties of the printed parts. Scan speed, laser power, and hatch distance are among the most influential process parameters in L-PBF because, depending on their combination, different solidification mechanisms take place. However, the procedure for selecting these parameters can be expensive from an experimental point of view. Therefore, it is necessary to identify simplified models that allow fast and reliable optimization of the parameters in L-PBF. Furthermore, the choice of parameters cannot be based exclusively on qualitative aspects but must also consider the productivity of the process to obtain a satisfactory compromise. Increasing productivity leads to the formation of lack of fusion porosity which should be avoided. This paper proposes a procedure for selecting parameters based on a semi-analytical thermal model, which, together with a geometric-based defect model, allows identifying an optimality region where good solidification and productivity are considered. The optimization is carried using a properly defined utility function. The procedure is validated through the production of AISI 316L specimens using an industrial L-PBF system. [ABSTRACT FROM AUTHOR]

The paper presents an experimental study on the relationship between process parameters and residual stresses in cylindrical grinding. In particular, the influence of the depth of cut (a) and the peripheral velocity of the workpiece ([v.sub.w]) was investigated. Residual stresses were found to depend on both parameters, but the effect of the peripherial velocity depends on the grinding conditions. In 'easy to grind' conditions an increase in workpiece velocity leads to an increase in residual stresses, but in 'difficult to grind' conditions an increase in workpiece velocity results in a decrease in residual stresses. Consequently, two joint parameters, [Z.sub.w] = a * [v.sub.w], and [K.sub.w]=a/[v.sub.w], were used to predict residual stresses. Regression analysis was then performed to determine the analytic relationship between the joint parameters and the residual stresses in 'easy' and 'difficult' grinding conditions. Finally, the influence of wheel wear, feed rate, sparkout and wheel dressing was investigated. The study showed that the workpiece feed rate does not seem to influence the residual stresses, while sparkout, wheel wear, and wheel dressing significantly affect the level of residual stresses generated during machining. [DOI: 10.1115/1.1428328]

Additive Manufacturing technologies found many applications in the last decade in many industries. AM parts show good mechanical properties, but the presence of porosity is still limiting the adoption of these technologies on a wider scale. X-ray computed tomography (XCT) has become a successful measurement tool to characterize AM parts, especially for detecting defects. In this work, a test object was used to simulate internal porosity and test the accuracy of the XCT measurement. Repeatability and reproducibility of the XCT system were investigated as well as the influence of the internal defects position and size on the measurement error. [ABSTRACT FROM AUTHOR]

Using the Z-transform method, closed-form analytical expressions for evaluating; the performance of flexible manufacturing systems (FMS) are derived. The formulae are based on the operational analysis framework and allow the dependence of the performance measures on the main operational parameters to be clarified. Balanced, and nearly or completely unbalanced systems, are considered. In more complex cases, to improve the efficiency of computation, an algorithm is introduced, which decomposes the system into balanced and unbalanced parts, and allows the formulae already derived for these simple cases to be utilized. The intermediate results are expressed in the form of finite discrete sequences. From the convolution of these sequences, the behaviour of the whole system is obtained. [ABSTRACT FROM AUTHOR]