Microstructure and properties of welds between 5754 Al alloys and AZ31 Mg alloys using a Yb:YAG laser

The authors wish to thank Mr. Henri ANDRZEJEWSKI for his technical assistance in laser experiments. The authors wish to place their sincere thanks to Professor Philippe BOURNOT and Dr. Eric VALERIO for helpful discussions.Dissimilar laser beam welding between A5754 Al alloy and AZ31 Mg alloy with the plate thickness of 2 mm was investigated. Complex flow pattern characterized by a large volume of intermetallic compounds Al12Mg17 and Al3Mg2 is formed in the fusion zone. Microhardness measurement of the dissimilar welds presents an uneven distribution due to the complicated microstructure of the weld, and the maximum value of microhardness in the fusion zone is much higher than of the base materials

From 3-geometry transition amplitudes to graviton states

18 pagesIn various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected to project quantum states of the geometry on the solutions of the Wheeler-DeWitt equation. We study the relation between this formalism and conventional quantum field theory methods. We consider the propagation kernel of 4d Lorentzian general relativity in the temporal gauge, defined by a conventional formal Feynman path integral, gauge fixed à la Fadeev-Popov. If space is compact, this turns out to depend only on the initial and final 3-geometries, while in the asymptotically flat case it depends also on the asymptotic proper time. We compute the explicit form of this kernel at first order around flat space, and show that it projects on the solutions of all quantum constraints, including the Wheeler-DeWitt equation, and yields the correct vacuum and n-graviton states. We also illustrate how the Newtonian interaction is coded into the propagation kernel, a key open issue in the spinfoam approach

Application of BPR and Simulation tools to the Italian Supreme Court of Cassation

LAUREA MAGISTRALEScopo – Il PNRR (Piano Nazionale di Ripresa e Resilienza) recentemente approvato impone una serie di obiettivi alle istituzioni italiane, tra cui la CSC (Corte Suprema di Cassazione). Gli obiettivi fissati per la CSC sono in termini di Disposition Time – il tempo necessario per completare l'elaborazione di un fascicolo – e di generazione dell'arretrato per la II, la IV e la V Sezione Civile del CCS. Per questi motivi, l'obiettivo di questo studio è quello di mappare tutti i processi, reingegnerizzare le fasi critiche e creare uno strumento di simulazione in grado di prevedere sia il Disposition Time che la Generazione del Backlog Design/Metodologia/Approccio – Lo studio è stato condotto utilizzando i dati del documento Deloitte, da cui è stato sviluppato un modello Excel. Tale modello è in grado di concedere per ogni attività del processo, un intervallo di tempi da computare nel software di simulazione, che alla fine stima la produttività del processo in analisi. Risultati – La mappatura dei processi e la simulazione effettuata hanno evidenziato che l'attuale modo di operare per il SCC non è sufficiente per raggiungere gli obiettivi fissati nel PNRR. Infatti, secondo il DT calcolato per l'as-is, la CSC impiega circa 1316 giorni, contro i 976 giorni del Disposition Time target. Per questo motivo, attraverso la reingegnerizzazione della fase di filtro e spoglio, descritta in questo studio, è stato possibile ridurre significativamente la generazione di DT e backlog, per soddisfare i limiti fissati nel piano PNRR. Originalità/Valore – I principali contributi svolti dallo studio sono la mappatura dei processi e la simulazione di tutte le fasi della II, IV e V Sezione Civile del SCC. Tra gli scenari di simulazione che sono stati realizzati, è stato realizzato uno specifico scenario puntuale interamente per il decisore. Infatti, questo scenario consente al decisore di comprendere in modo intuitivo ma completo, come varia la produttività del processo analizzato quando vengono modificati input specifici. In quanto tale, il decisore è in grado di ottimizzare la fase selezionata del processo, consentendo una costante messa a punto della soluzione proposta da questa ricerca. Implicazioni pratiche e manageriali – Tra gli scenari di simulazione che sono stati realizzati, è stato realizzato uno specifico scenario puntuale interamente per il decision maker. Infatti, questo scenario consente al decisore di comprendere in modo intuitivo ma completo, come varia la produttività del processo analizzato quando vengono modificati input specifici. In quanto tale, il decisore è in grado di ottimizzare la fase selezionata del processo, consentendo una costante messa a punto della soluzione proposta da questa ricerca. Limiti e ricerche future - Tutti i tempi utilizzati come input nei file Excel sono stime e, come tali, contengono elementi di variabilità. Inoltre, lo stesso strumento di simulazione presentava alcuni grossi difetti; anzi, in alcuni casi, la simulazione si è fermata per mancanza di potenza di calcolo, a causa di un numero eccessivo di istanze in attesa in prossimità di colli di bottiglia. Infine, dato che l'organizzazione è attualmente poco matura dal punto di vista digitale, sono da considerare gli sviluppi futuri per quanto riguarda l'utilizzo dell'IA per automatizzare i processi. Infatti, mentre attualmente il rischio di rifiuto di una soluzione di IA è ritenuto molto probabile, in un futuro piuttosto prossimo, è probabile che tali barriere al cambiamento possano cadere, e le soluzioni di IA potrebbero essere prese in considerazione per ottimizzare i processi, riducendo ulteriormente la Disposizione Tempo.Purpose – The recently approved PNRR (Piano Nazionale di Ripresa e Resilienza) imposes a number of objectives to Italian institutions, including the SCC (Supreme Court of Cassation). The goals set for the SCC are in terms of Disposition Time – the time needed for a file to be fully processed – and backlog generation for the II, the IV and the V Civil Sections of the SCC. For these reasons, the goal of this study is to map all the processes, reengineer the critical phases, and create a simulation tool capable of predicting both the Disposition Time and the Backlog Generation Design/methodology/approach – The study has been conducted using data from the Deloitte document, from which an Excel model has been developed. Such model is able to grant for each activity of the process, a range of times to compute into the simulation software, which ultimately estimates the productivity of the process under analysis. Findings – The process mapping and the simulation carried out have highlighted that the current way of operating for the SCC is not sufficient to achieve the targets set in the PNRR. Indeed, according to the DT calculated for the as-is, the SCC takes about 1316 days, against the 976 days of the target Disposition time. For this reason, through the reengineering of the Filter and Examination phase described in this study, it has been possible to significantly reduce the DT and backlog generation, to fulfill the boundaries set in the PNRR plan. Originality/Value – The main contribution brought by the study is the process mapping and analysis of each phase of the II Section, IV Section, and V Section of the Civil District. Indeed, for each phase of the process, activities have been modelled in terms of the timings, resources and working hours, with the scope of creating a simulation tool capable of predicting whether the targets set in the PNRR are feasible or not. Theoretical and managerial implications – The main contributions carried out by the study are the process mapping and the simulation of all the phases of the II, IV and V Civil Section of the SCC. Among the simulation scenarios that have been created, a specific punctual scenario was created entirely for the decision maker. As a matter of facts, this scenario allows the decision maker to understand in an intuitive but comprehensive way, how the productivity of the process analyzed varies when specific inputs are modified. As such, the decision maker is capable of optimizing the selected phase of the process, allowing for a constant fine tuning of the solution proposed by this research. Limits and further research – All the timings used as inputs in the Excel files are estimations, and as such, they contain elements of variability. Moreover, the simulation tool itself had some major flaws; indeed, in some cases, the simulation halted due to a lack of computing power, because of an excessive number of waiting instances in the proximity of bottlenecks. Finally, given that the organization is currently not very mature from a digital point of view, future developments regarding the use of AI to automate processes are to be considered. Indeed, while currently the risk of rejection of an AI solution is deemed as very probable, in a rather near future, it is likely that such barriers to change might fall, and AI solutions might be considered to optimize the processes, further reducing the Disposition Time

On the perturbative expansion of a quantum field theory around a topological sector

The idea of treating general relativistic theories in a perturbative expansion around a topological theory has been recently put forward in the quantum gravity literature. Here we investigate the viability of this idea, by applying it to conventional Yang--Mills theory on flat spacetime. We find that the expansion around the topological theory coincides with the usual expansion around the abelian theory, though the equivalence is non-trivial. In this context, the technique appears therefore to be viable, but not to bring particularly new insights. Some implications for gravity are discussed.Comment: 7 page

LIFE+IPNOA mobile prototype for the monitoring of soil N2O emissions from arable crops: First-year results on durum wheat

Agricultural activities are co-responsible for the emission of the most important greenhouse gases: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Development of methodologies to improve monitoring techniques for N2O are still needful. The LIFE+IPNOA project aims to improve the emissions monitoring of nitrous oxide from agricultural soils and to identify the agricultural practices that can limit N2O production. In order to achieve this objective, both a mobile and a stationary instrument were developed and validated. Several experimental field trials were set up in two different sites investigating the most representative crops of Tuscany (CentralItaly), namely durum wheat, maize, sunflower, tomato and faba bean. The field trials were realized in order to test the effect on N2O emissions of key factors: tillage intensity, nitrogen fertiliser rate and irrigation. The field trial on durum wheat was set up in 2013 to test the effect of tillage intensity (minimum and conventional tillage) and nitrogen fertilisation rate (0, 110, 170 kg N ha–1) on soil N2O flux. Monitoring was carried out using the IPNOA mobile prototype. Preliminary results on N2O emissions for the durum wheat growing season showed that mean daily N2O fluxes ranged from –0.13 to 6.43 mg m–2 day–1 and cumulative N2O-N emissions over the period ranged from 827 to 2340 g N2O-N ha–1. Tillage did not affect N2O flux while increasing nitrogen fertilisation rate resulted to significantly increase N2O emissions. The IPNOA mobile prototype performed well during this first year of monitoring, allowing to catch both very low fluxes and peaks on N2O emissions after nitrogen supply, showing a good suitability to the field conditions

Diode laser welding of ABS: Experiments and process modeling

The laser beam weldability of acrylonitrile/butadiene/styrene (ABS) plates is determined by combining both experimental and theoretical aspects. In modeling the process, an optical model is used to determine how the laser beam is attenuated by the first material and to obtain the laser beam profile at the interface. Using this information as the input data to a thermal model, the evolution of the temperature field within the two components can be estimated. The thermal model is based on the first principles of heat transfer and utilizes the temperature variation laws of material properties. Corroborating the numerical results with the experimental results, some important insights concerning the fundamental phenomena that govern the process could be extracted. This approach proved to be an efficient tool in determining the weldability of polimeric materials and assures a significant reduction of time and costs with the experimental exploration

Perturbative quantum gravity with the Immirzi parameter

We study perturbative quantum gravity in the first-order tetrad formalism. The lowest order action corresponds to Einstein-Cartan plus a parity-odd term, and is known in the literature as the Holst action. The coupling constant of the parity-odd term can be identified with the Immirzi parameter of loop quantum gravity. We compute the quantum effective action in the one-loop expansion. As in the metric second-order formulation, we find that in the case of pure gravity the theory is on-shell finite, and the running of Newton's constant and the Immirzi parameter is inessential. In the presence of fermions, the situation changes in two fundamental aspects. First, non-renormalizable logarithmic divergences appear, as usual. Second, the Immirzi parameter becomes a priori observable, and we find that it is renormalized by a four-fermion interaction generated by radiative corrections. We compute its beta function and discuss possible implications. The sign of the beta function depends on whether the Immirzi parameter is larger or smaller than one in absolute value, and the values plus or minus one are UV fixed-points (we work in Euclidean signature). Finally, we find that the Holst action is stable with respect to radiative corrections in the case of minimal coupling, up to higher order non-renormalizable interactions.Comment: v2 minor amendment

Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin