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El diferencial de la empresa cooperativa
No full textEn este artículo vamos a fijar la mirada en el modelo de empresa cooperativa. ¿Qué supone ser una empresa cooperativa? ¿Cuáles son sus principales características y señas de identidad? O, dicho de otro modo, ¿qué diferencia a la empresa cooperativa de otro tipo de empresas? ¿Qué dificultades y retos enfrenta el modelo cooperativo? ¿Se trata de una fórmula obsoleta o, por el contrario, con proyección de futuro? Estas son algunas de las preguntas que han guiado nuestra reflexión
Determination of emissivity and temperature of tool rake face when cutting AISI 4140
Get PDFA method for measuring tool temperature in the tool/chip contact zone of the rake face of a tool during dry orthogonal cutting using thermography is presented. This method used a new calibration method that combined with a standard camera calibration allows to estimate surface emissivity. The effect of material deposition and tool oxidation on the emissivity is analyzed. These techniques effectively showed thermal field on the rake face when machining AISI 4140
In-Line Dimensional Inspection of Warm-Die Forged Revolution Workpieces Using 3D Mesh Reconstruction
Get PDFIndustrial dimensional assessment presents instances in which early control is exerted
among “warm” (approx. 600 ºC) pieces. Early control saves resources, as defective processes are
timely stopped and corrected. Existing literature is devoid of dimensional assessment on warm
workpieces. In response to this absence, this manuscript presents the implementation and results of an optical system which performs in-line dimensional inspection of revolution warm workpieces singled out from the (forming) process. Our system can automatically measure, in less than 60 s, the circular runout of warm revolution workpieces. Such a delay would be 20 times longer if cool-downs were required. Off-line comparison of the runout of T-temperature workpieces (27 ºC ≤ T ≤ 560 ºC) shows a maximum difference of 0.1 mm with respect to standard CMM (Coordinate Measurement Machine) runout of cold workpieces (27 ºC), for workpieces as long as 160 mm. Such a difference is acceptable for the forging process in which the system is deployed. The test results show no correlation between the temperature and the runout of the workpiece at such level of uncertainty. A prior-to-operation Analysis of Variance (ANOVA) test validates the repeatability and reproducibility (R&R) of our measurement system. In-line assessment of warm workpieces fills a gap in manufacturing processes where early detection of dimensional misfits compensates for the precision loss of the vision system.
The integrated in-line system reduces the number of defective workpieces by 95%
Model for a sustainable energy transition in Spain. Case study in a district of the Basque Country
Get PDFThe current energy model available in Spain is obsolete due to various circumstances, some technological, others social, economic or environmental. This supposes a tension in the economic and social model of the country. Changing the current energy model to an alternative one requires a period of transition. This transition, in turn, requires a planned action and implies the identification of available energy in the vicinity, the awareness and commitment of citizens, the mobilization of technical, technological and economic resources and the design of a generation model and Proximity distribution, efficient. In this new model, compliance with environmental commitments (reduction of GHG emissions) together with the generation of economic activity and the guarantee that the transition will not give rise to any uncertainty regarding the availability and security of supply, must be unquestionable commitments. This document summarizes a research carried out in the Basque Country (Spain), which aims to promote the change of energy model. It presents the different phases of the study carried out, the methodology used, the conclusions, the road map of the transition process, the legislative situation in Spain and some reflections on the research carried out and the results obtained. Also, the study has analyzed the model of energy transition made by five European countries, studying their particularities and the factors that have contributed to the transition and the change of the energy model in them. Models of good practices in Spain have also been studied
Electromechanical Properties of PVDF-Based Polymers Reinforced with Nanocarbonaceous Fillers for Pressure Sensing Applications
Get PDFPolymer-based composites reinforced with nanocarbonaceous materials can be tailored for functional applications. Poly(vinylidene fluoride) (PVDF) reinforced with carbon nanotubes (CNT) or graphene with different filler contents have been developed as potential piezoresistive materials. The mechanical properties of the nanocomposites depend on the PVDF matrix, filler type, and filler content. PVDF 6010 is a relatively more ductile material, whereas PVDF-HFP (hexafluropropylene) shows larger maximum strain near 300% strain for composites with CNT, 10 times higher than the pristine polymer. This behavior is similar for all composites reinforced with CNT. On the other hand, reduced graphene oxide (rGO)/PVDF composites decrease the maximum strain compared to neat PVDF. It is shown that the use of different PVDF copolymers does not influence the electrical properties of the composites. On the other hand, CNT as filler leads to composites with percolation threshold around 0.5 wt.%, whereas rGO nanocomposites show percolation threshold at ≈ 2 wt.%. Both nanocomposites present excellent linearity between applied pressure and resistance variation, with pressure sensibility (PS) decreasing with applied pressure, from PS ≈ 1.1 to 0.2 MPa−1. A proof of concept demonstration is presented, showing the suitability of the materials for industrial pressure sensing applications
Fast preparation route to high-performances textured Sr-doped Ca 3 Co 4 O 9 thermoelectric materials through precursor powder modification
Get PDFThis work presents a short and very efficientmethod to produce high performance textured Ca3Co4O9thermoelectric materials through initial powders modifica-tion. Microstructure has shown good grain orientation, andlow porosity while slightly lower grain sizes were obtained insamples prepared from attrition milled powders. All samplesshow the high density of around 96% of the theoretical value.These similar characteristics are reflected in, approximately,the same electrical resistivity and Seebeck coefficient valuesfor both types of samples. However, in spite of similar powerfactor (PF) at low temperatures, it is slightly higher at hightemperature for the attrition milled samples. On the otherhand, the processing time reduction (from 38 to 2 h) whenusing attrition milled precursors, leads to lower mechanicalproperties in these samples. All these data clearly point out tothe similar characteristics of both kinds of samples, with adrastic processing time decrease when using attrition milledprecursors, which is of the main economic importance whenconsidering their industrial production
El efecto de la participación en el bienestar de las personas y la sostenibilidad económica de las organizaciones
Get PDFRadiant waste heat recovery from steelmaking and glass industry
Get PDFThis paper tackles the problem of industrial waste heat recovery through an unexploited heat transfer mechanism: thermal radiation. Energy intensive industries have a considerable potential of unused radiant heat, which cannot be recovered through existing methods. That potential energy is quantified for the main identified industries: steel and glassmaking. Then, a radiant heat capturing device allowing high temperature heat capture is designed according to process requirements. Finally, recoverable heat is estimated and potential uses are proposed
Analysis of the pilot survey INKLUGI about aging and disabilities to promote Inclusive Design in industry
Get PDFThis study is part of the project INKLUGI. The main objective of the project is to create new tools that help to introduce Inclusive Design methods in the industry of the region of Gipuzkoa. To make companies understand the aging of the population as an opportunity for innovation and competitiveness is necessary to create new quantitative tools. The survey about disability and aging is the best way to gather data for a quantitative data base that will feed the future quantitative tools for Inclusive Design. In this study the process followed to carry out the pilot survey INKLUGI is presented. Then, the results obtained from the survey are analysed and discussed in a collaborative workshop with stakeholders. Finally, the contributions of experts from different sectors are explained