Multidomain Simulation Model for Analysis of Geometric Variation and Productivity in Multi-Stage Assembly Systems

Nowadays, the new era of industry 4.0 is forcing manufacturers to develop models and methods for managing the geometric variation of a final product in complex manufacturing environments, such as multistage manufacturing systems. The stream of variation model has been successfully applied to manage product geometric variation in these systems, but there is a lack of research studying its application together with the material and order flow in the system. In this work, which is focused on the production quality paradigm in a model-based system engineering context, a digital prototype is proposed to integrate productivity and part quality based on the stream of variation analysis in multistage assembly systems. The prototype was modelled and simulated with OpenModelica tool exploiting the Modelica language capabilities for multidomain simulations and its synergy with SysML. A case study is presented to validate the potential applicability of the approach. The proposed model and the results show a promising potential for future developments aligned with the production quality paradigm

SYSML4TA: A SysML Profile for Consistent Tolerance Analysis in a Manufacturing System Case Application

Tolerance analysis is a key engineering task that is usually supported by domain-specific analysis models and tools that are generally not connected to the system functionality. The model-based system engineering (MBSE) approach is a potential solution to this limitation, but it has not yet been deeply explored in this type of mechanical analysis, for which some problems need to be explored. One of these issues is the capacity of languages such as SysML to describe solution principles based on active surfaces that participate in functionality and are present for tolerance analysis. Thus, this study explored the possibilities that enable SysML to represent these geometries and their mathematical relationships based on Topologically and Technologically Related Surfaces (TTRS) theory and aligned with Geometric Dimensioning and Tolerancing (GD&T) standards. Additionally, the capacity of SysML to assure the consistency of tolerance analysis models is also explored, due to the limitations identified in analysis languages like Modelica. In this context, this paper presents a SysML profile for tolerance analysis modeling (SysML4TA), containing domain-specific semantics (concepts and constraints) to assure the completeness of the analysis models and consistency between the different models considered in the integrated model of the system. Finally, a case study applied to a manufacturing context is presented to validate the capacity of SysML to solve the identified problems.La herencia reconstruida. Crecimiento agrario y transformaciones del paisaje tras las conquistas de al-Andalus (siglos XII-XV

A Tool Condition Monitoring System Based on Low-Cost Sensors and an IoT Platform for Rapid Deployment

Tool condition monitoring (TCM) systems are key technologies for ensuring machining efficiency. Despite the large number of TCM solutions, these systems have not been implemented in industry, especially in small- and medium-sized enterprises (SMEs), mainly because of the need for invasive sensors, time-consuming deployment solutions and a lack of straightforward, scalable solutions from the laboratory. The implementation of TCM solutions for the new era of the Industry 4.0 is encouraging practitioners to look for systems based on IoT (Internet of Things) platforms with plug and play capabilities, minimum interruption time during setup and minimal experimental tests. In this paper, we propose a TCM system based on low-cost and non-invasive sensors that are plug and play devices, an IoT platform for fast deployment and a mobile app for receiving operator feedback. The system is based on a sensing node by Arduino Uno Wi-Fi that acts as an edge-computing node to extract a similarity index for tool wear classification; a machine learning node based on a BeagleBone Black board that builds the machine learning model using a Python script; and an IoT platform to provide the communication infrastructure and register all data for future analytics. Experimental results on a CNC lathe show that a logistic regression model applied on the machine learning node can provide a low-cost and straightforward solution with an accuracy of 88% in tool wear classification. The complete solution has a cost of EUR 170 and only a few hours are required for deployment. Practitioners in SMEs can find the proposed approach interesting since fast results can be obtained and more complex analysis could be easily incorporated while production continues using the operator’s feedback from the mobile app

Contributions of MS metabolomics to gilthead sea bream (Sparus aurata) nutrition. Serum fingerprinting of fish fed low fish meal and fish oil diets

The aim of this study was to evaluate the impact of fish meal (FM) and fish oil (FO) replacement by plant proteins and oils in the serum metabolome of two-year old gilthead sea bream (Sparus aurata) fed from early life stages with control and experimental diets. Randomly selected fish were overnight sampled and clotted serum was used for metabolomics fingerprinting by means of ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. >12,500 different m/z ions were detected, and Partial Least Squares-Discriminant analysis separated fish fed control and plant-based diets, with a 71% of variance explained and 44% of variance predicted by the two first components. After variable importance in projection (VIP) and Benjamini-Hochberg test correction filtering, 50 endogenous compounds were elucidated as highly discriminant features of dietary treatment. Most of them were lipid-related compounds and reflected the different fatty acid composition of dietary oils, whereas changes in N-acyl taurines, cytidine and nucleoside related compounds would indicate changes in tissue repair and DNA degradation processes. Untargeted analysis also identified some exogenous compounds as markers of marine and vegetable raw materials. In the case of hercynine (antioxidant fungi and mycobacteria product), this was exemplified by a close lineal association between circulating and feed levels. Targeted approaches were focused on vitamins and a clear reduction of B12, indirectly assessed via methylmalonic acid levels, was found in fish fed vegetable diets. Conversely, serum riboflavin (B2) and pantothenic acid (B5) levels were consistently increased, which highlighted the close link between nutrition and gut microbiota

Development of a modular kit to improve DFA learning

Ponencia presentada en: 9th Manufacturing Engineering Society International Conference (MESIC 2021) 23-25 jun 2021, Gijόn,DFA (Design for assembly) is an important part of the contents included in some of the manufacturing courses taught at Jaume I University. DFA is a tool to analyse and improve product design from an assembly point of view. Although DFA contents had been covered using different teaching activities (theoretical, problem and laboratory sessions), the results in students’ assessment revealed that the expected learning outcomes were not being achieved. In particular, results were especially unsatisfactory in the practical application of DFA. Students misunderstood concepts such as “handling” and “insertion” operations, and failed at identifying assembly problems related to thickness or alignment among others. A learning by doing approach has been proved to improve students’ learning and engagement, as they take an active role and have the opportunity of doing things themselves. In a previous work, a specific modular and reconfigurable kit to improve DFA learning by experimentation was designed. Based on this work, this paper presents the analysis of the results obtained in two different courses where the modular kit has been used by students in a new seminar session

In-beam γ-ray spectroscopy of 136Te at relativistic energies

The reduced transition probability B(E2; 0+ 1 →2+ 1 ) to the first excited 2+ state of the neutron-rich nucleus 136Te, with two protons and two neutrons outside the doubly magic 132Sn core, was measured via Coulomb excitation at relativistic energies at the RIKEN Radioactive Isotope Beam Factory. A value of B(E2)= 0.191(26) e2b2 was extracted from the measured inelastic scattering cross section on an Au target taking into account the contributions from both Coulomb and nuclear excitations. In addition, an upper limit for the transition strength to a 2+ state of mixed-symmetry character in the excitation energy range of 1.5–2.2 MeV was determined and compared to the predictions of various theoretical calculations. Because of the high statistics gathered in the present experiment the error of the deduced B(E2) value is dominated by the systematic uncertainties involved in the analysis of Coulomb excitation experiments at beam energies around 150 MeV/u. Therefore, the latter are for the first time assessed in detail in the present work.Spanish Ministerio de Economía y Competitividad (FPA2014-57196-C5-4-P, FPA2017-84756-C4-2-P, FIS2014-53448-C2-1-P

Tentativas de suicidio en el municipio de Valencia.

Se obtuvo información sobre las tentativas de suicidio registradas en los libros de urgencias de los hospitales de Valencia ejecutados por residentes de este municipio mayores de 14 años, desde 1982 a 1985. Su análisis mostró que las tasas, la edad, el sexo y el método empleado fueron similares a lo descrito en otros países europeos. Sin embargo, la proporción de personas remitidas a su casa sin mediar ingreso fue comparativamente muy elevad

Tentativas de suicidio en el municipio de Valencia.

Se obtuvo información sobre las tentativas de suicidio registradas en los libros de urgencias de los hospitales de Valencia ejecutados por residentes de este municipio mayores de 14 años, desde 1982 a 1985. Su análisis mostró que las tasas, la edad, el sexo y el método empleado fueron similares a lo descrito en otros países europeos. Sin embargo, la proporción de personas remitidas a su casa sin mediar ingreso fue comparativamente muy elevad

Chiral unitary approach to S-wave meson baryon scattering in the strangeness S=0 sector

We study the S-wave interaction of mesons with baryons in the strangeness S=0 sector in a coupled channel unitary approach. The basic dynamics is drawn from the lowest order meson baryon chiral Lagrangians. Small modifications inspired by models with explicit vector meson exchange in the t-channel are also considered. In addition the pi pi N channel is included and shown to have an important repercussion in the results, particularly in the isospin 3/2 sector.Comment: 23 pages, LaTeX, 21 figure