IsoCor: isotope correction for high-resolution MS labeling experiments

Summary Mass spectrometry (MS) is widely used for isotopic studies of metabolism and other (bio)chemical processes. Quantitative applications in systems and synthetic biology require to correct the raw MS data for the contribution of naturally occurring isotopes. Several tools are available to correct low-resolution MS data, and recent developments made substantial improvements by introducing resolution-dependent correction methods, hence opening the way to the correction of high-resolution MS (HRMS) data. Nevertheless, current HRMS correction methods partly fail to determine which isotopic species are resolved from the tracer isotopologues and should thus be corrected. We present an updated version of our isotope correction software (IsoCor) with a novel correction algorithm which ensures to accurately exploit any chemical species with any isotopic tracer, at any MS resolution. IsoCor v2 also includes a novel graphical user interface for intuitive use by end-users and a command-line interface to streamline integration into existing pipelines. Availability and implementation IsoCor v2 is implemented in Python 3 and was tested on Windows, Unix and MacOS platforms. The source code and the documentation are freely distributed under GPL3 license at https://github.com/MetaSys-LISBP/IsoCor/ and https://isocor.readthedocs.io/.

Friction Stir Weld Modeling of Aluminum Alloys

Friction stir welding (FSW) process of aluminum alloys was investigated using a two-dimensional Eulerian formulation coupling viscoplastic flow and heat transfer and strain hardening. The thermal equation for the temperature was modified to stabilize temperature distribution using a Petrov-Galerkin method. The evolution equation for strength was calculated using a streamline integration method. Predicted strength was compared with experiments. Based on crystal plasticity, texture evolution was predicted during FSW of AA6061.