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Article
Publication date: 14 July 2020

Vicente Hernández, Felipe Galleguillos, Nicole Sagredo and Ángela Machuca

The study aims to test the color fastness of wool and linen fabrics dyed by simple immersion in ethanol dissolutions of fungal dyes.

203

Abstract

Purpose

The study aims to test the color fastness of wool and linen fabrics dyed by simple immersion in ethanol dissolutions of fungal dyes.

Design/methodology/approach

Ethanol dissolutions of Talaromyces australis and Penicillium murcianum dyes were prepared to a concentration of 0.3% and used to dye wool and linen samples by immersion. Color fastness to washing, dry cleaning, wet and dry rubbing, perspiration and light, were tested according to AATCC standards.

Findings

Color fastness reached acceptable results at dry cleaning and wet and dry rubbing by crocking but did not performed well at laundering, perspiration and light exposure. Results indicate that ethanol dissolutions of tested dyes had better affinity for wool fabrics than linen, but the dyeing method requires further improvements to be considered attractive for full scale applications.

Originality/value

In this work sustainability of fabrics dyeing is improved by using natural pigments produced by filamentous fungi and a method to dye that requires no increment of temperature and mordants.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 2
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 20 August 2019

Merlina A. Navarro Villanueva, Luis A. Soto Hernández, Melquisedec Vicente Mendoza, Ángel de J. Morales Ramírez and Fernando Juárez López

This paper aims to study the microstructural hot corrosion behaviour of the sintered Y2SiO5 ceramic silicate under a Na2SO4 + V2O5 mixture at an engine representative temperature…

135

Abstract

Purpose

This paper aims to study the microstructural hot corrosion behaviour of the sintered Y2SiO5 ceramic silicate under a Na2SO4 + V2O5 mixture at an engine representative temperature of 1150°C. Y2SiO5 is a promising candidate for thermal barrier coatings (TBC) due to its excellent chemical stability at high temperatures. As a continuous source of Y3+, it is expected that Y2SiO5 environmental barrier coating may prolong the lifetime of TBC systems by stopping the degradation caused by the loss of the Y2O3 stabilizer.

Design/methodology/approach

Two routes were chosen for the yttria silicate powder synthesis by sol-gel from TEOS and APTES precursors as the difference in Si source changed the ratio of Y2SiO5/Y2Si2O7 phases. Hot corrosion studies using Na2SO4 and V2O5 mixtures were conducted on both surfaces of APTES and TEOS tablets at 1150°C for 8 h in atmospheric air. The morphology and microstructure analyses of the silicate samples after hot corrosion tests were carried out using a SEM and X-ray diffraction analyse techniques.

Findings

Based on the degradation, the general status of the APTES tablet after hot corrosion presents a better hot corrosion resistance at a temperature of 1150°C than does that of the TEOS tablet. In the TEOS tablet, the crystal morphology of NaY9Si60O26 woodchip shapes with a size of 60 µm is developed on the surface for finally initiating some cracks. In the APTES case, the crystal morphology of rod-like shapes with a size of 100 µm is developed; hence, a dense thick layer predominately postpones the reaction of V2O5 and Na2SO4 with yttria silicate, and consequently, less damage is observed.

Originality/value

Coating yttria silicate preparation is very complicated; the problems of a high synthesis temperature, long production period and low yield still need to be solved. Under these perspectives, ceramics prepared via spark plasma sintering (SPS) can reach theoretical high densities and a fine grain size can be retained after the SPS process; hence, well resistance to the corrosion in molten salts is expected to obtain for the sintered yttria silicate tablets.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 March 2005

Michel Bellet, Olivier Jaouen and Isabelle Poitrault

The present paper addresses the computer modelling of pipe formation in metal castings.

1145

Abstract

Purpose

The present paper addresses the computer modelling of pipe formation in metal castings.

Design/methodology/approach

As a preliminary, a brief review of the current state‐of‐the‐art in pipe shrinkage computation is presented. Then, in first part, the constitutive equations that have to be considered in thermomechanical computations are presented, followed by the main lines of the mechanical finite element resolution. A detailed presentation of an original arbitrary Lagrangian‐Eulerian (ALE) formulation is given, explaining the connection between the Lagrangian and the quasi Eulerian zones, and the treatment of free surfaces.

Findings

Whereas most existing methods are based on thermal considerations only, it is demonstrated in the current paper that this typical evolution of the free surface, originated by shrinkage at solidification front and compensating feeding liquid flow, can be effectively approached by a thermomechanical finite element analysis.

Research limitations/implications

Future work should deal with the following points: identification of thermo‐physical and rheological data, automatic and adaptive mesh refinement, calculation of the coupled deformation of mold components, development of a two‐phase solid/liquid formulation.

Practical implications

An example of industrial application is given. The proposed method has been implemented in the commercial software THERCAST® dedicated to casting simulation.

Originality/value

The proposed numerical methods provide a comprehensive approach, capable of modelling concurrently all the main phenomena participating in pipe formation.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 15 no. 2
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 19 June 2017

Lars Lindner, Oleg Sergiyenko, Moises Rivas-López, Daniel Hernández-Balbuena, Wendy Flores-Fuentes, Julio C. Rodríguez-Quiñonez, Fabian N. Murrieta-Rico, Mykhailo Ivanov, Vera Tyrsa and Luis C. Básaca-Preciado

The purpose of this paper is to present a novel application for a newly developed Technical Vision System (TVS), which uses a laser scanner and dynamic triangulation, to determine…

396

Abstract

Purpose

The purpose of this paper is to present a novel application for a newly developed Technical Vision System (TVS), which uses a laser scanner and dynamic triangulation, to determine the vitality of agriculture vegetation. This vision system, installed on an unmanned aerial vehicle, shall measure the reflected laser energy and thereby determine the normalized differenced vegetation index.

Design/methodology/approach

The newly developed TVS shall be installed on the front part of the unmanned aerial vehicle, to perform line-by-line scan in the vision system field-of-view. The TVS uses high-quality DC motors, instead of previously researched low-quality DC motors, to eliminate the existence of two mutually exclusive conditions, for exact positioning of a DC motor shaft. The use of high-quality DC motors reduces the positioning error after control.

Findings

Present paper emphasizes the exact laser beam positioning in the field-of-view of a TVS. By use of high-quality instead of low-quality DC motors, a significant reduced positioning time was achieved, maintaining the relative angular position error less than 1 per cent. Best results were achieved, by realizing a quasi-continuous control, using a high pulse-width modulated duty cycle resolution and a high execution frequency of the positioning algorithm.

Originality/value

The originality of present paper is represented by the novel application of the newly developed TVS in the field of agriculture. The vitality of vegetation shall be determined by measuring the reflected laser energy of a scanned agriculture zone. The paper’s main focus is on the exact laser beam positioning within the TVS field-of-view, using high-quality DC motors in closed-loop position control configuration.

Details

Industrial Robot: An International Journal, vol. 44 no. 4
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 17 October 2023

Asael Islas-Moreno, Daniel Emigdio Uriza-Ávila, Ana Lieseld Guzmán-Elizalde and Gabriel Aguirre-Álvarez

The study aims to analyze the effect of the previous preparation and the work carried out in the field during a study trip on the development of competencies in agribusiness…

54

Abstract

Purpose

The study aims to analyze the effect of the previous preparation and the work carried out in the field during a study trip on the development of competencies in agribusiness students.

Design/methodology/approach

The destination was the pineapple area of the Papaloapan Lower Basin in Mexico, and 42 students from 6 different semester levels participated. The students answered a test prior to the trip, received an evaluation for their activities in the field and prepared reports and posters as products of the experience. The relationship between the scores obtained was examined through a comparative analysis.

Findings

The findings are framed in the cyclical model of experiential learning with four stages (feeling, watching, thinking and doing) by Kolb (1984). It is found that the acquisition of specific knowledge about what the experience will entail leads to better preparation, motivation and confidence to live the experience (potentiation of feeling and watching). In turn, specific knowledge and better use of experience promote the development of problem solving, interpersonal and communication skills (potentiation of thinking and doing).

Research limitations/implications

Statistical representativeness is not a quality of the study since it is based on a comparative analysis.

Originality/value

The study analyzes an educational component of great value in the business area, about which little is known in the agribusiness subarea.

Details

Journal of Agribusiness in Developing and Emerging Economies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2044-0839

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Article
Publication date: 29 July 2019

Beatrice I.J.M. Van der Heijden, Pascale M. Le Blanc, Ana Hernandez, Vicente Gonzalez-Roma, Jesus Yeves and Juan P. Gamboa

The purpose of this paper is to gain a better understanding of the antecedents of the quality of graduates’ jobs when they enter the job market after university graduation.

974

Abstract

Purpose

The purpose of this paper is to gain a better understanding of the antecedents of the quality of graduates’ jobs when they enter the job market after university graduation.

Design/methodology/approach

Survey data collected from 173 Spanish bachelor and master’s degree university graduates at two time points (two months before and six months after graduation, approximately) were analyzed by means of path analysis.

Findings

A moderated mediation model was tested, where the relationship between the horizontal fit (HF) between the university degree subject and the student’s job and the quality of the graduate’s job after graduation is mediated by self-perceived employability and moderated by the time devoted to a student job. Results showed that the relationship between HF and job quality was partially mediated by self-perceived employability. However, contrary to the proposed hypothesis, this relationship did not depend on the time devoted to a student job.

Originality/value

This study contributes to improving the understanding about how and why university students’ work experience is related to the quality of their jobs as fresh graduates.

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Book part
Publication date: 16 September 2014

Shaila Rao, Cristina M. Cardona and Esther Chiner

The focus of special education around the globe may be to provide specialized instruction to meet unique needs of children to help them achieve their full potential. However, each…

Abstract

The focus of special education around the globe may be to provide specialized instruction to meet unique needs of children to help them achieve their full potential. However, each country around the globe may also have its own unique issues, barriers, legal frames, policies, and practices, as well as a history of its origin and evolution of policies and practices that govern special education in that country. This chapter describes how special education in Spain originated and evolved to its current state. It includes the following chapter sections: origins of special education in Spain; legislative acts; prevalence and incidence of various recognized disability areas; an overview of Spain’s education system including special needs education; current assessment and intervention practices; teacher education practices; family involvement considerations; and future challenges to special education.

Details

Special Education International Perspectives: Practices Across the Globe
Type: Book
ISBN: 978-1-78441-096-4

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Article
Publication date: 28 June 2022

Rishi Parvanda and Prateek Kala

Fused deposition modelling (FDM) has gained popularity owing to its capability of producing complex and customized profiles at relatively low cost and in shorter periods. The…

200

Abstract

Purpose

Fused deposition modelling (FDM) has gained popularity owing to its capability of producing complex and customized profiles at relatively low cost and in shorter periods. The study aims to extend the use of FDM printers for 3D printing of low melting point alloy (LMPA), which has applications in the electronics industry, rapid tooling, biomedical, etc.

Design/methodology/approach

Solder is the LMPA with alloy’s melting temperature (around 200°C) lower than the parent metals. The most common composition of the solder, which is widely used, is tin and lead. However, lead is a hazardous material having environmental and health deteriorating effects. Therefore, lead-free Sn89Bi10Cu non-eutectic alloy in the form of filament was used. The step-by-step method has been used to identify the process window for temperature, print speed, filament length (E) and layer height. The existing FDM printer was customized for the present work.

Findings

Analysis of infrared images has been done to understand discontinuity at a certain range of process parameters. The effect of printing parameters on inter-bonding, width and thickness of the layers has also been studied. The microstructure of the parent material and deposited bead has been observed. Conclusions were drawn out based on the results, and the scope for the future has been pointed out.

Originality/value

The experiments resulted in the process window identification of print speed, extrusion temperature, filament length and layer height of Sn89Bi10Cu which is not done previously.

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Book part
Publication date: 3 June 2020

Carlos Riojas and Angélica Basulto

This chapter's objective is to analyze, with a long-term perspective, the formation of an entrepreneurial culture in Mexico's Midwest, specifically in the state of Jalisco, in…

Abstract

This chapter's objective is to analyze, with a long-term perspective, the formation of an entrepreneurial culture in Mexico's Midwest, specifically in the state of Jalisco, in terms of the geographical environment, the culture in general, and the local economic institutions that, when viewed interconnectedly, will globally impact the practices, representations, and imaginaries of persons who at a given time have made the decision to undertake profitable economic activities – individual and collective entrepreneurs, in other words. To this end, we have divided the text into two sections. In the first, we conceptually review what we understand as entrepreneurial culture; in principle, we deconstruct its terms and then conjugate them from a social science perspective. We also emphasize the importance of studying the milieu as a scenario of action with different arenas, where a variety of agents have been involved. In the second part, without sidelining conceptual analysis, we present concrete empirical evidence of the role played by culture and local economic institutions that shape entrepreneurial culture in Midwestern Mexico over time, specifically in Jalisco. The text ends with some final considerations.

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Book part
Publication date: 12 January 2021

María del Carmen Pardo

The purpose of this chapter is to analyze the profile of public administration concerning its capacity to authoritatively assign values to a society, and in particular to the…

Abstract

The purpose of this chapter is to analyze the profile of public administration concerning its capacity to authoritatively assign values to a society, and in particular to the political system in Mexico. Many of the recent transformations in the Mexican public administration have occurred in a context in which a democratic opening of the political system has been the main trait of public life. This is the main light under which these changes in Mexico's federal public administration in recent years should be read.

The article explores the structural features of both the government and the federal public administration in Mexico. In particular, the transformation of the administrative apparatus not only in quantitative but also in qualitative terms is explained as a result of a change in the balance between the public and private sectors in recent decades, as well as the experience of the Professional Career Service and its impact on public officials in Mexico. We examine the links of the bureaucracy with political parties and civil society, as well as the political relationships within the public administration itself. We also describe accountability within the federal public administration. We explore recent reform and change processes in Mexico's administrative apparatus. Finally, some considerations are given to the opportunities and challenges facing the contemporary Mexican public administration as a result of having huge problems and at the same time partial solutions.

Details

The Emerald Handbook of Public Administration in Latin America
Type: Book
ISBN: 978-1-83982-677-1

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