Agricultural holdings: hindsight and foresight

In France, the concept of the agricultural holding is a result of a lengthy social construction in which the stages in classification and statistical work have proceeded in tune with the major political struggles and social debates of the 19th and 20th centuries. Some people argue that the “ agricultural holding ” is now just a term revived from the past for the modern “ agricultural enterprise ”. Sociologists and economists therefore need to reconsider the significance and relevance of this concept. The diversity of the ways of practising agricultural activities encountered in French households shows that the economic and social realities referred to in this concept are far too varied for its use in defining a productive sector having an institutional existence. Neither can it be used to demark the social groups that will be entitled to benefit from the support measures of agricul-tural and rural development policies. As a basic statistical unit, however the concept of the agricultural holding can provide a com-mon basic unit for measuring agricultural activity, and the land used for this activity, thereby permitting the integration of results concerning the different functions of agricultural activity (production, natural resource management, land use, socio-economic cohesion, etc.). From this angle, the statistical notion of the agricultural holding as presently defined is of increasing interest for the management of new agricultural and rural policies and for social sciences research.Knowledge, agricultural statistics,agricultural holding,history of concepts, multifunctionality

GHOST: experimenting countermeasures for conflicts in the pilot's activity

An approach for designing countermeasures to cure conflict in aircraft pilots’ activities is presented, both based on Artificial Intelligence and Human Factors concepts. The first step is to track the pilot’s activity, i.e. to reconstruct what he has actually done thanks to the flight parameters and reference models describing the mission and procedures. The second step is to detect conflict in the pilot’s activity, and this is linked to what really matters to the achievement of the mission. The third step is to design accu- rate countermeasures which are likely to do bet- ter than the existing onboard devices. The three steps are presented and supported by experimental results obtained from private and professional pi- lots

Convergence to the Reynolds approximation with a double effect of roughness

We prove that the lubrication approximation is perturbed by a non-regular roughness of the boundary. We show how the flow may be accelerated using adequate rugosity profiles on the bottom. We explicit the possible effects of some abrupt changes in the profile. The limit system is mathematically justified through a variant of the notion of two-scale convergence. Finally, we present some numerical results, illustrating the limit system in the three-dimensional case

The question of “evidence” in the emergence of evidence-based or evidence-aware policies in agriculture

Evidence-based or evidence-aware policy approaches are used in many different sectors (health, education, etc.). These approaches are less common in agriculture but are gradually emerging. Analysis of debates surrounding this trend sheds light on the particular nature of the difficulties faced by public decision-makers who are willing to use available scientific knowledge. After examining certain misunderstandings which arise in the international debate over evidence-based policy approaches, this paper addresses two specific issues: (i) the problems of competing evidence for using knowledge in the design of public policies and (ii) the potential role of rationalization tools in a possible "depoliticisation" of public decision-making.knowledge, agriculture, policy, evidence, Agricultural and Food Policy, B29, D8, Q01, O3,

Transformations of agricultural extension services in the EU: Towards a lack of adequate knowledge for small-scale farms

This paper examines the consequences of the transformations of extension services for small scale farms. It presents the results of investigations embedded in regulation theory, which combine a comparative institutional analysis, statistical data processing (national agricultural census) and direct surveys. We describe the transformations in the EU and show that they make it more difficult for small farms to access extension services and to benefit from “front office” support (i.e. direct advice from extensionists). Finally, we emphasize that due to the modification of the knowledge production regime, these small farms may also suffer new specific adverse effects resulting from the re-organization of the "back-office" R&D activities of these extension services (i.e. knowledge base updating, database building, scientific experiments, etc.).Agricultural extension services, Small-scale farms, Institutional Analysis, Europe, Knowledge, Research and Development/Tech Change/Emerging Technologies, Q16, Q12, B52, P51, D83,

Effect of microchannel aspect ratio on residence time distributions and the axial dispersion coefficient

The effect of microchannel aspect ratio (channel depth/channel width) on residence time distributions and the axial dispersion coefficient have been investigated for Newtonian and shear thinning non-Newtonian flow using computational fluid dynamics. The results reveal that for a fixed cross sectional area and throughput, there is a narrowing of the residence time distribution as the aspect ratio decreases. This is quantified by an axial dispersion coefficient that increases rapidly for aspect ratios less than 0.3 and then tends towards an asymptote as the aspect ratio goes to 1. The results also show that the axial dispersion coefficient is related linearly to the Reynolds number when either the aspect ratio or the mean fluid velocity is varied. However, the fluid Péclet number is a linear function of the Reynolds number only when the aspect ratio (and therefore hydraulic diameter) is varied. Globally, the results indicate that microchannels should be designed with low aspect ratios (≤ 0.3) for reduced axial dispersion

Distributed archive and single access system for accelerometric event data : a NERIES initiative

We developed a common access facility to homogeneously formatted accelerometric event data and to the corresponding sheet of ground motion parameters. This paper is focused on the description of the technical development of the accelerometric data server and the link with the accelerometric data explorer. The server is the third node of the 3-tier architecture of the distributed archive system for accelerometric data. The server is the link between the data users and the accelero- metric data portal. The server follows three main steps: (1) Reading and analysis of the end-user request; (2) Processing and converting data; and (3) Archiving and updating the accelerometric data explorer. This paper presents the description of the data server and the data explorer for accessing data

Black anodic coatings for space applications: study of the process parameters, characteristics and mechanical properties

Black inorganic anodized aluminium alloys are used for managing passive thermal control on spacecraft and for avoiding stray light in optical equipment. Spalling of these coatings has sometimes been observed after thermal cycling on 2XXX and 7XXX aluminium alloys. This phenomenon could generate particulate contamination in satellites and may affect mission lifetime. In this work, the influences of the four main steps of the process (pretreatments, sulphuric anodizing, colouring and sealing) on the coating characteristics have been studied for a 7175 T7351 aluminium alloy. The chemical heterogeneity of the coating has been underlined, and its mechanical behaviour observed through crazing. Scratch-testing, used to evaluate coating adhesion to its substrate, revealed the negative impact of thermal cycling