Michel Bellet, Olivier Jaouen and Isabelle Poitrault
The present paper addresses the computer modelling of pipe formation in metal castings.
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
Keywords
The purpose of this paper is to present personal testimony of one of the early researchers on small to medium‐sized enterprises (SMEs) and entrepreneurship in France.
Abstract
Purpose
The purpose of this paper is to present personal testimony of one of the early researchers on small to medium‐sized enterprises (SMEs) and entrepreneurship in France.
Design/methodology/approach
The story of a half‐century evolution is divided into five decades, of SME and entrepreneurship development in France. The development of the French academic system of research on SME and entrepreneurship is described through some teams.
Findings
During the two early decades (1955‐1975), both the social legitimacy and economic competitiveness sharply and deeply lowered, while that after the world crisis (1975) until nowadays (2005), the social, political, and economic interest for SME and entrepreneurship has continuously increased.
Research limitations/implications
The academic research pioneered SME during the 1960s, and entrepreneurship during the 1980s. The historical development of the national network of teams and associations is described, increasingly including the international context.
Practical implications
Beyond the personal testimony, this contribution enlightens the problems entailed by the lack of legitimacy of the spirit of enterprise anchored in French society, and, more generally, in all the societies averse to individual risk taking.
Originality/value
The testimony is based on the personal experience of one scholar who early promoted in the French academic system Master and Doctoral courses on SME and entrepreneurship. It outlines some original concepts relative to small firms.
Details
Keywords
Alexandre Mondoux, Bastien Christinet, Roxane Fenal and Olivier Viret
This study aims to identify the economic impact of a potential implementation of a Climatic Reserve for the Swiss predominant white grape variety (Chasselas) vinified in the AOC…
Abstract
Purpose
This study aims to identify the economic impact of a potential implementation of a Climatic Reserve for the Swiss predominant white grape variety (Chasselas) vinified in the AOC (controlled designation of origin) category. The Climatic Reserve would imply the possibility of harvesting an additional quantity of grapes whose commercialization in wine would be delayed until it is approved by the relevant authority.
Design/methodology/approach
The impact of a potential implementation of this wine supply management tool is simulated through an innovative method that combines the vector autoregressive (VAR) model to estimate the influence of the previous consumptions and productions on the current consumption and linear regression [ordinary least square (OLS) method] to estimate the price elasticity to measure the evolution of the price depending on the simulated consumption. The VAR model is based on state-level data about production, stocks, and consumption (all the channels of distribution combined), while the OLS regression for estimating price elasticity uses the retail market data (Nielsen Panel). With the sales and price variables on a monthly frequency design, the latter represents about 40% of the wine market in Switzerland.
Findings
According to simulations carried out at the level of a region from the canton of Vaud in Switzerland (2000–2018), the increase in turnover linked to the release of the Climatic Reserve would be +3.1% for the indigenous white grape variety Chasselas.
Originality/value
The Climatic Reserve is a wine supply management tool that could complement the existing yield restriction, which does not significantly influence the quantities sold, according to previous studies. Our paper contributes to the literature by demonstrating the economic advantage of this supply management tool to deal with the increasingly frequent climatic hazards in wine production and market. The methodology could be applied to other wine regions (contexts) or other agricultural sectors.