M Fouaidy

M Saki

N Hammoudi

L Simonet

Electromechanical characterization of piezoelectric actuators subjected to a variable preloading force at cryogenic temperature

Electromechanical characterization of piezoelectric actuators subjected to a variable preloading force at cryogenic temperature

Introduction

Piezoelectric actuators, which are integrated into the cold tuning system [START_REF] Bosland | Mechanical study of the 'Saclay piezo tuner' PTS (Piezo Tuning System[END_REF][START_REF] Fouaidy | Integration of piezoelectric actuators in the piezotuner developed at Saclay[END_REF], will be used to compensate [START_REF] Liepe | Dynamic Lorentz compensation with a fast piezoelectric tuner[END_REF][START_REF] Lilje | Characteristics of a Fast Piezo-Tuning Mechanism for Superconducting Cavities[END_REF] the small mechanical deformations of the cavity wall induced by Lorentz forces [START_REF] Sekalski | Smart materials based system operated at 2K used as a superconducting cavity tuner for VUV-FEL purpose[END_REF] for accelerating gradients up to 35 MV/m. In order to provide for a reliable operation of the accelerator, the piezoelectric actuators (~30.000-40.000 units for ILC 1 [START_REF] Gamp | On the preference of cold RF technology for the international linear collider[END_REF]) should function satisfactorily for a period close to machine life duration (~20 years). The corresponding actuator lifetime requirements should be much higher than 3.210 9 cycles (pulsed mode, repetition rate: 5 Hz). Moreover, previous studies showed that the life time of piezostacks depends strongly on the applied preloading pressure P Load (Fig. 1) with an optimum value P Load ~10MPa at T=300 K. On the other hand, the actuator displacement versus preloading pressure characteristics (Fig. 1) is no monotonic: the maximum displacement is observed for P Load in the range 20MPa-50 MPa [START_REF] Bindig | Application of piezoceramic multilayer actuators, experiences and solution[END_REF]. Further, the lifetime versus preload curves depends strongly on actuator material and fabrication process. Due to the lack of data for the operating conditions in the actual tuner (i.e. under vacuum and cryogenic conditions), it is necessary to perform an experimental investigation of electromechanical behavior of actuators subjected to axial preload at cryogenic temperature.

Description of low temperature preload experiment

The main goals of low temperature preload experiment are: 1) Study the effect of a variable and controllable axial preload on the electromechanical properties of the piezoelectric actuator (stroke, capacitance, loss factor, impedance, etc), 2) Development of a procedure for applying, adjusting and controlling the preload, 3) Study of the behavior of piezostacks as force sensor, 4) Measurement of the mechanical stiffness of the actuator, 5) Study the actuator resonance spectrum versus preload.

Experimental set-up

Principle of experiment and mechanical design

The apparatus should allow to applying and measure a controlled and adjustable axial force in the range 1kN-4kN to the piezoelectric actuator. Moreover, the piezoelectric actuator should be subjected to this force in an environment similar to the operating conditions in the tuner namely under vacuum (pressure<10 -5 mbar) and at cryogenic temperatures. We have designed and constructed a device dedicated to low temperature preloading experiment. The simplest way for applying a vertical downward compressing force is naturally to use gravity. But due to the relatively high value (~100 kg) of the mass (in case of direct load on the actuator axis) needed for achieving force of ~1kN, it is obvious that a lever arm system with a magnification factor ~10-15 (lever arms ratio) should be used. The operating principle of the method is presented in Fig. 1. The piezostacks to be tested is enclosed in a stainless steel vacuum chamber which will be immersed in a liquid helium bath. A rotating arm located at room temperature (T~300 K) outside the cryostat allows applying a vertical force (along the actuator axis) to the piezostacks via a high stiffness transmission rod. The preloading force applied to the actuator is simply adjusted by varying the load at the extremity of the rotating arm. At the mechanical equilibrium, the sum of the momentums of all the forces is equal to zero. Assuming a negligible friction on the rotation axis, the preloading F force is simply given by the law of conservation of angular momentum:

g L L m L L Fc F P A A P C . . . ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ + ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = (1)
Where m A is the masse of the rotating arm, L P , L A and L C are respectively the distances from the rotation axis of the piezostacks axis (L P ), the center of mass of the arm (L A ) and the loading mass(L A ) and g the gravity constant.

Taking into account the available space on the upper flange of the cryostat insert, which support vacuum pumps and other components, the values of the lengths L P , L C are respectively 30mm, 430mm leading to a lever arm ratio r=L P /L C =14.66. The key element of the preloading is the rotating arm; consequently it was carefully designed using Finite Element Method numerical simulations in order to verify that it behaves as a rigid body. Note that the simulation model includes the transmission rod and the actuator. The different arms studied and the main results concerning their mechanical behavior are listed in Table 1.

Cross-section Shape Dimensions (mm The computed displacements for the square shape cross-section arm made of stretched steel are shown in Fig. 2. These results leads to a ratio ∆Xc/∆Xp=17.7 of the vertical displacements at the masse location and along the piezostacks axis respectively, which is close to the value of lever arm ratio r=L P /L C =14.7. The relative difference (i.e. 20%) is due to the finite rigidity of the arm. As expected, due to their low stiffness, the first two arms of rectangular shape and made of aluminium these two arms don't behave as a rigid body. More precisely, they show a high deflexion or bending leading to a ratio ∆Xc/∆Xp one order of magnitude higher than the target r=14.7.

Fig. 2: Computed displacements of the square shape cross-section arm made of stretched steel

The test-cell [START_REF] Fouaidy | Characterization of piezoelectric actuators used for SRF cavities active tuning at low temperature[END_REF][START_REF] Fouaidy | Full Characterization at Low Temperature of Piezoelectric Actuators Used for SRF Cavities Active Tuning[END_REF][START_REF] Fouaidy | Electromechanical, thermal properties and radiation harness tests of Piezoelectric Actuators at Low Temperature[END_REF] is placed inside the cryostat (diameter: Φ350, height: 1500mm?) while the rotating arm and the displacement sensors are located outside the LHe vessel at room temperature. The preloading force is transmitted to the piezostacks via a transmission rod equipped with a stainless steel bellow at its upper extremity. The transmission rod should fulfil two main requirements: 1) stiffness higher than 25 N/µm, 3) conduction heat load from T=300 K to the liquid helium (LHe) bath (T=4 K) lower than 750 mW for 1m length. A stainless steel tube or a bare rod could be used (Table 2). These results show that a 16mm diameter bare rod fulfils the above requirement with minimum heat load to Lhe. Moreover the upper extremity of the transmission rod is connected to a stainless bellow at room temperature (Fig. 3). The buckling force for the first rod (diameter: Φ 1 =6mm, length L 1 =90mm) used for previous tests (i.e. without preloading force) is F B =3.9 kN in the ideal case (i.e. no defect in the material or welding). For the safety of the people, the rule for cryostat design a factor 3 (safety margin) is needed. Consequently this rod should be changed in order to fulfil this requirement, namely F B > 3.F max = 12 kN (F max = 4kN: maximum preloading force). An 8 mm diameter stainless steel connecting rod, which fits in the actual bellow, satisfies this criterion (e.g., F B =12.2 kN).

Geometry

Description of the apparatus

The test-cell [START_REF] Fouaidy | Characterization of piezoelectric actuators used for SRF cavities active tuning at low temperature[END_REF][START_REF] Fouaidy | Full Characterization at Low Temperature of Piezoelectric Actuators Used for SRF Cavities Active Tuning[END_REF][START_REF] Fouaidy | Electromechanical, thermal properties and radiation harness tests of Piezoelectric Actuators at Low Temperature[END_REF], illustrated in Fig. 4a and Fig. 4b, consists mainly in a cylindrical vacuum chamber with a removable thin end plate. The actuator, which is housed in the chamber, is sandwiched between the lower rigid flange (thickness: 32.5mm) and the upper thin stainless steel (SS) sheet (thickness: 0.2mm). A special fixture based on a sphere and cone system was used to avoid shear and torsion forces on the piezostacks. Two stainless steel pieces are glued at the two extremities of the piezostacks: hemispherical holder at the upper extremity and thin cylinder with conical grove at the lower extremity. Further, the actuator is equipped with a heater (manganin wire) and a calibrated thermometer [START_REF] Chanzy | Cryogenic thermometer calibration system using a helium cooling loop and a temperature controller[END_REF] (CERNOX resistor) in order to vary and control the piezostacks temperature. The thermometer allows also the measurement of the heating due to dielectric losses. The operating principle of this device is the following: 1) Actuator mode: a voltage is applied to the piezoactuator which expand leading to a deformation of the upper thin sheet; the resulting motion is transmitted to the displacement sensors at room temperature via a Φ16 stainless steel rod. 2) Force sensor mode: a loading force is applied to the piezostacks via de transmission rod and the response of the actuator (i.e. capacitance and transient voltage) is measured. A close view of the upper part of the insert showing the rotating arm, the vacuum pumps is presented in Fig. 6. The block diagram of the data acquisition system is illustrated in Fig. 7.

Fig. 6: Photograph of the upper part of the insert ready for cryogenic test

Experimental procedure

The block diagram of the data acquisition system is illustrated in Fig. 7.

GPIB

Prior to the low temperature tests, the test-cell is evacuated to P v <10 -5 mBar and we proceed to the calibration of all the displacement sensors are calibrated at T≅ 300 K using the piezoelectric as reference and the manufacturer calibration data (i.e., displacement vs. actuator voltage). This calibration is performed for different values of the preloading force F. The vessel (cryostat) is filled with Liquid helium in order to cool down the system to 4.2K (Normal boiling point of helium) the test-cell. The bath temperature T bath is then decreased simply by reducing the vapor pressure of the system P bath , which is kept constant during all the tests: P bath (e.g., T bath =1.8K) is set to 16 mbar and stabilized by means of a DIP pressure controller. The cryogenic tests are performed in the range T= 1.8K-300K. Using the heater, the actuator temperature T is then regulated at the desired value and the measurements are performed. In the course of the experiments, we performed the following measurements [START_REF] Fouaidy | Characterization of piezoelectric actuators used for SRF cavities active tuning at low temperature[END_REF][START_REF] Fouaidy | Full Characterization at Low Temperature of Piezoelectric Actuators Used for SRF Cavities Active Tuning[END_REF][START_REF] Fouaidy | Electromechanical, thermal properties and radiation harness tests of Piezoelectric Actuators at Low Temperature[END_REF] at a given temperature and for different values of the preloading force F: 1) Displacement versus voltage characteristics (e.g., calibration), 2) Dielectric properties of the actuator (e.g., capacitance: Cp, dielectric constant: ε r , loss factor: tg(δ), complex impedance: amplitude (Z) and phase (θ)) using the LCR meter, 3) Heating ∆T due to dielectric losses as function of the frequency (f) and amplitude (V) of the sinusoidal signal applied to the piezostacks, 4) Transient response of the actuator to a steep variation ∆F of the preloading force F.

Experimental results and discussion

Repeatability test at T=4.4K

The sensitivity of a PICMA type piezostacks to a preloading axial force at cryogenic temperature was investigated. The variations of the relative capacitance ∆Cp= Cp-Cp 0 , with reference to the capacitance Cp 0 of the actuator when it is subjected to the arm preload F 0 =733 N, as function of the preloading force F at T= 4.2 K are shown in Fig. 8. In order to measure the repeatability of the experimental data, two runs were performed for F increasing from 0 up to 4 kN. The data show a linear behavior of ∆Cp vs. F. Moreover, we observe a good repeatability of ±5% for the slope ∆Cp/∆F=25nF/kN at T=4.4K for F increasing from 0 to 4 kN.

Sensitivity to preloading at T=2.05K

The sensitivity of the actuator to preloading was measured at T=2.05 (T=2 K: ILC operating temperature) for increasing and decreasing load (Fig. 9). Non linear effects are observed at low preloading force when F is increased from zero: they are due to friction, stick-slip among non linear phenomena in the preloading device mechanism (rotating arm, bellows,…). Further, these data clearly show a large hysteresis for increasing and decreasing the preloading force. This behavior could be attributed to the intrinsic irreversibilities in the piezoelectric material itself. At T= 2.05K, the measured sensitivity to preloading are 16nF/kN (respectively 10nF/kN) for F increasing (respectively decreasing).

Effect of temperature on the sensitivity to preloading

We investigate the effect of the actuator temperature on its sensitivity to preloading. Systematic measurements of ∆Cp vs. F were performed for T in the range 1.7 K-300K. The corresponding data are presented in Fig. 10-Fig. 11.

Piezostacks as dynamic force sensor

The behavior of the piezostacks as dynamic force sensor was also studied. The transient response of a PICMA type actuator to a steep preload variation ∆F=150 N at T=2K is presented in Fig. 13. The results call for the following remarks: 1) a steep voltage increase (capacitor charging) followed by an exponential decrease (capacitor discharging) is observed, 2) the peak actuator voltage ∆V p is repeatable (3 %).

. The previous data lead to the following conclusions: 1) the actuator is a very sensitive dynamic force sensor with strong temperature dependence: ∆V p /∆F=4.7V/kN at T=2K and ∆V p /∆F=21.4V/kN at T=4.2K, 2) the response is linear (∆V p ∝ ∆F), 3) the phenomenon is reversible with a good repeatability (3%).

Conclusion

The work presented in this report was initiated in the frame of the IPN Orsay activities within the CARE project WP#8 devoted to the development of Fast Active Cold Tuning System (FACTS). The FACTS will be used for the control and stabilization of SRF cavities frequency (cavity tuning at cryogenic temperature, dynamic compensation of Lorentz detuning and damping of micro-phonics). In this context, we designed and constructed an apparatus dedicated to the study of the electromechanical and dynamic behavior of prototype piezoelectric actuator subjected to variable preloading force at cryogenic temperatures. The preloading of piezostacks actuators is mandatory in order to increase their lifetime. The preloading apparatus was successfully used for testing a PICMA type piezoelectric actuator for temperature T in the range 2K-300K and preloading force F ranging from 733N to 4kN. In the whole temperature range, the actuator capacitance Cp increases linearly with F. The sensitivity of the actuator to preloading ∆Cp/∆F shows exponential dependence on T: ∆Cp/∆F increases with T from 16 nF/kN at T=2 K to 426 nF/kN at T=300 K (increasing preload). Notice that Cp vs. F curve shows a large hysteresis which seems to be intrinsic to the material of the actuator. The behavior of the piezostacks as dynamic force sensor was also studied at T=2 K and T=4.2K. The experimental data show the reversibility and good repeatability (3%). These data lead to several observations: a) the response is linear namely the peak voltage is proportional to preload variation (∆V p ∝ ∆F) and change de sign with ∆F, b) the actuator is a very sensitive dynamic force sensor with strong temperature dependence: ∆V p /∆F=4.7V/kN at T=2K and ∆V p /∆F=21.4V/kN at T=4.2K. These calibration data were used successfully for measuring the variations of the force applied to the actuator by the tuning system in operation on C45 cavity [START_REF] Fouaidy | Integration of piezoelectric actuators in the piezotuner developed at Saclay[END_REF]. The corresponding results will be presented in a next report.

1 PFig. 1 :

 11 Fig. 1: A) Sketch of lifetime versus preloading pressure, B) Displacement versus preloading pressure at different voltages (R. Binding et al., see ref. 7).

Fig. 1 :

 1 Fig.1 : Sketch of the experimental method

Fig. 3 :

 3 Fig.3 : Connection of the transmission rod to the bellow.

FigFig. 5 :

 5 Fig. 4a: Diagram of the test-cell

Fig. 7 :

 7 Fig. 7: Block diagram of the data acquisition system

Fig. 8 :

 8 Fig. 8: Sensitivity to preloading at T=4.4 K (Reproducibility test), Cp 0 =3.134 µF.

Fig. 9 :

 9 Fig. 9: Capacitance versus preload at T=2.05 K), Cp 0 =2.879 µF.

Fig. 10 :Fig. 11 :Fig. 12 :

 101112 Fig. 10: Capacitance versus preload for T in the range 2.05 K-83K

Fig. 13 :Fig. 15 :Fig. 16 :

 131516 Fig. 13: Transient response of a PICMA type actuator to a steep preload variation ∆F=150 N at T= 2 K.

Table 1 : The rotating arms studied (∆Xp and ∆Xc are respectively the vertical displacements on the piezostacks axis and at the masse location)

 1

		3 )	Material	∆Xp (µm)	∆Xc (µm)	∆Xc /∆Xp Bend (µm)
	rectangle	40x10x500 Aluminum	66.1	27490	416	26521
	Rectangular tube	20x20x500 Aluminum	66.4	12379	186	11406
	(2mm wall thickness)
	square	45x45x500	Stretched	59.4	913	17.7	42.5
			steel

Table 2 : Mechanical and thermal characteristics of two possible transmission rods.

 2

	Stiffness (N/µm) Heat load (mW)

ILC : International Linear Collider, previously TESLA (TeV Energy Superconducting Linear Accelerator)

ACKNOWLEDGEMENT

We acknowledge the support of the European Community-Research Infrastructure Activity under the FP6 "Structuring the European Research Area" program (CARE, contract number RII3- CT-2003-506395)


Gildas Renou

Keywords: Environmentalism, valuation, pragmatic sociology, Italy, place attachment, critique, environmental conflicts

From public participation to place-based resistance.

From public participation to place-based resistance. Environmental critique and modes of valuation in the struggles against the expansion of the Malpensa airport.

Abstract:

Through an analysis of the 40-year history of conflicts triggered by the repeated attempts to expand the Malpensa airport in northern Italy, this paper seeks to show the heuristic strength of using the concept of modes of valuation of the environment to discuss the transformations of environmental critique over time in their relation to social change. I argue that, beyond empirical specifics, the trajectory witnessed in this case -from public participation to placebased resistance -reflects more generalized dynamics that can be found in many other conflicts over large infrastructural projects in contemporary Europe. The article is organized as follows: in the first section I briefly introduce the concept of modes of valuation of the environment, which is inspired by recent work in pragmatic sociology. In particular, I distinguish between public, local and emplaced modes of valuation. In the second and third sections I provide an analysis of the struggles against the Malpensa airport expansion from 1970 to 2014. Here, I distinguish three phases of mobilization, which I discuss in terms of the transformations that can be observed in the arguments that actors develop to fight or support the airport expansion. I argue that these transformations are articulated not only with changing action repertoires but also with evolving social and sociotechnical imaginaries that convey specific understandings of the environment as a matter of political concern. This analysis shows that, far from being simply a case of citizens' resistance to change, the mobilization This article aims to contribute a reflection on the transformations of environmental critique since the 1970s. By environmental critique, I refer to a form of contestation of the socioeconomic order oriented toward producing a specific change in society: a new understanding of the place of "nature" in the political community (Latour 1993;2004a). I argue that a key issue for environmental critique is that of how experience, and in particular the experience of the environment, can contribute to the critical power of reason applied to environmental problems.

The relevance of this issue for environmental critique is made clear once we consider that this critique fundamentally asks for the political recognition of a plurality of "languages of valuation of the environment" [START_REF] Martinez-Alier | The Environmentalism of the Poor. A Study of Ecological Conflicts and Valuation[END_REF], 2008) or "environmental values." "Environmental values" are intended here as the plurality of ways in which environments and their constituents matter to people (O'Neill, Holland and Light 2008: 1). In this sense, different kinds of value might be attributed to the environment, since there are a large variety of declinations of what can be experienced as an environmental good. Such recognition of the variety of environmental values raises the question of how people reach an agreement on the kind of experience of the environment that should be valorized in the deliberation concerning a given course of action.

Through an analysis of the 40-year history of conflicts triggered by a series of proposals to expand the Malpensa airport in the territory of the Regional Natural Park of the Ticino River Valley in northern Italy, I seek to show the heuristic strength of using the concept of modes of valuation of the environment to discuss the transformations of environmental critique over time in their relation to social change. Beyond the empirical specificities of the Malpensa case, I argue that the trajectory of transformations witnessed in this context -from public participation to place-based resistance -is in fact indicative of a more generalized dynamic of environmental critique that can be found in many other conflicts over large infrastructural projects in contemporary Europe.

The article unfolds as follows. In the first section I briefly introduce the concept of modes of valuation of the environment and its relevance for understanding critique and social change. I distinguish between public, local and emplaced modes of valuation. By the adjective "emplaced", I refer here to a form of knowledge and appreciation that takes place primarily at the aesthetic level, understood as the level of perception and corporeal sensibility. The concept of modes of valuation and the typology I introduce are inspired by the sociology of "regimes of engagement" (ROE) developed by Laurent Thévenot, on the basis of the pragmatic sociology of critique he elaborated together with Luc Boltanski during the 1980s.

In partial disagreement with an understanding of pragmatic sociology as limited in its capacity to explain long-term trends (cf. [START_REF] Delanty | Varieties of Critique in Sociological Theory and Their Methodological Implications for Social Research[END_REF], I argue that pragmatic tools can be usefully mobilized to support an analysis of the transformations of critique over time. In the second and third sections I provide an analysis of the mobilizations against the Malpensa airport expansion that have taken place over the course of more than 40 years. This struggle is a typical case of mobilization against infrastructure policy in Italy, and one of the oldest and most widely debated at the national level, for its political and economic implications. Events related to the Malpensa expansion led the Italian flag carrier Alitalia Airlines to financial turmoil, ultimately resulting in its going bankrupt in 2008 [START_REF] Di | Dossier Malpensa[END_REF]. I distinguish three phases of mobilization corresponding to three different plans of airport expansion. I discuss these three phases in terms of the arguments that emerge to support or to criticize the airport expansion, observed from the perspective of the modes of valuation of the environment they combine. Arguments are connected not only with action repertoires but also with evolving social and sociotechnical imaginaries that convey specific understandings of the environment as a matter of political concern. According to Taylor (2004:92) "social imaginary" can be defined as "the ways people imagine their social existence, how they fit together with others, how things go on between them and their fellows, the expectations that are normally met, and the deeper normative notions and images that underlie these expectations." For Jasanoff and Kim (2015), the concept of "sociotechnical imaginaries" points more specifically to the ways in which visions of scientific and technological progress carry with them implicit ideas about public purposes, collective futures, and the common good.

This analysis shows that, far from being simply a case of citizens' resistance to change, the mobilization against the Malpensa airport has contributed to producing the cultural basis of an increased collective reflexivity about the many values that the environment takes on among community members in the airport region. In the final section I discuss some hypotheses concerning the usefulness of the notion of modes of valuation of the environment for exploring the emergence of a new type of radicalism in environmental struggles.

Critique, valuation and argumentation

My analysis of the transformations of environmental critique in the Malpensa case relies on an analytical frame based on French pragmatic sociology. 1 According to this approach, critique is related to the exercise of peoples' ordinary capacities for evaluative judgments [START_REF] Boltanski | De la Justification[END_REF]. Consequently, political critique depends on individuals' ordinary capacities for evaluating situations and claims based on the plurality of evaluative criteria that can be used for this purpose. Therefore, my emphasis is on the different kinds of critical capacities people rely on and exercise in order to promote particular visions of social change, while at the same time taking into account the situational, historical, and material constraints that might inhibit the emergence and the expression of these capacities.

More precisely I am interested in the analysis of those modes of valuation that social actors mobilize in order to politicize an issue. In the work that I am currently developing with Gildas Renou [START_REF] Centemeri | The contribution of a pragmatic sociology of valuation to the study of the social movement for sustainable degrowth[END_REF], we use the concept of mode of valuation to point to a variety of cultural forms that people can resort to in order to share a judgment concerning what matters, what is worthy or worthwhile, what is valuable, and what counts as important in a given situation, in order to be able to convene on a shared understanding about the proper way to "engage with" the situation at hand [START_REF] Thévenot | Pragmatic regimes governing the engagement with the world[END_REF][START_REF] Thévenot | L'action au pluriel. Sociologie des régimes d'engagement[END_REF][START_REF] Thévenot | The Plurality of Cognitive Formats and Engagements: Moving between the Familiar and the Public[END_REF]. In particular, we distinguish between public, local and emplaced modes of valuation.

The term valuation points here to the process through which an agent comes to identify what should count as valuable, so as to orient action in a given situation; the term evaluation then points to the assessment of that situation according to this criterion, by means of convenient and appropriated "tests of reality" 2 . In a similar way to how Annemarie Mol uses the concept of "logics" in her own work on care (Mol 2008: 10), the choice to speak of modes of valuation, and not simply of valuations, is explained by the interest in the comparison of distinguishable yet co-existing ways of valuing (and evaluating) that can account for the difficulties observable in actual processes of attribution of value, both at the individual and the collective level.

1 A general discussion of French pragmatic sociology is beyond the scope of this article. Various contributions provide a detailed analysis of this sociological tradition, its origin and developments: see in particular [START_REF] Bénatouïl | A Tale of Two Sociologies: The Critical and the Pragmatic Stance in Contemporary French Sociology[END_REF], [START_REF] Dodier | Action as a combination of 'common' worlds[END_REF], [START_REF] Wagner | After Justification: Repertoires of evaluation and the sociology of modernity[END_REF] and the special issue of the European Journal of Social Theory edited by Blokker (2011). 2 On the sociology of valuation and evaluation see [START_REF] Lamont | Toward a Comparative Sociology of Valuation and Evaluation[END_REF]. Tests of reality are performed by actors through specific objects, instruments or procedures expressly conceived or formatted in order to assess a certain form of the valuable [START_REF] Boltanski | De la Justification[END_REF].

The concept of modes of valuation is inspired by the pragmatic sociology of Laurent Thévenot and his framework of "regimes of engagement" (ROE). 3 The ROE approach enlarges the original pragmatic focus on publicly justifiable definitions of value -the "orders of worth" that Boltanski and Thévenot elaborate in their collaborative work De la justification 4in order to account for a wider variety of culturally shared definitions of the valuable that can orient people's judgments about what is worth doing in a given situation. In other words, according to Thévenot, there are other definitions of the valuable we should pay attention to beyond those public ones. These other definitions of the valuable are based on broad culturally shared understandings of the good -resting, for example, on the accomplishment of a plan of action (the "engagement in a plan" in Thévenot's terms), or on the familiarity with one's everyday surroundings, which contributes to basic material and affective sustenance [START_REF] Breviglieri | L'espace habité que réclame l'assurance intime de pouvoir: Un essai d'approfondissement sociologique de l'anthropologie capacitaire de Paul Ricoeur[END_REF]. The communication of what counts as valuable can then be more or less dependent from propositional language, the same being true for evaluation.

Hansen (2016: 132) argues that Thévenot "arrives at an extremely generic definition of critique as doubt relating to some kind of sacrifice which can take numerous forms from the most public and explicit ones described in On Justification to more subtle and less explicit ones such as irony, gestures, indecisiveness and groping." Reframing these remarks in terms of valuation, I would say that, according to Thévenot, critique potentially arises whenever the sacrifice of a mode of valuation -whether publicly justifiable or not -is judged as undue in a given situation. Political critique properly speaking takes roots in this more ordinary sense of critique, raising doubts about the appropriateness of the modes of valuation that underlie particular ways of governing and denouncing them as being unjust or, more broadly speaking, oppressive. But how do people succeed in making their critical voice publicly relevant?

The ROE approach, in continuity with the idea of justifiable action, rests on an understanding of publicness as a specific quality of action and of the modes of valuation that guide it. For [START_REF] Boltanski | De la Justification[END_REF] the public form of action in Western society has been socio-3 I opted for the concept of "mode" in order to address valuation trying not to separate issues of language and representation and issues touching upon what we can define as an ontological dimension. See on this point [START_REF] Latour | An Inquiry Into Modes of Existence[END_REF] and his concept of mode of existence. 4 Boltanski and Thévenot identify six different expressions of the common good in our society, from which they derive their six "orders of worth": market competition, industrial efficiency, fame, civic solidarity, domestic trust and inspiration. As historically-defined conceptual constructions, "orders of worth" evolve over time with the emergence of new legitimate justifications. Examples are the network-based worth theorized by [START_REF] Boltanski | Le nouvel esprit du capitalism[END_REF] or the "green worth" discussed by [START_REF] Lafaye | Une justification écologique? Conflits dans l'aménagement de la nature[END_REF]. These legitimate definitions of worth are the result of the specific political, material and intellectual history of Western European societies [START_REF] Wagner | A Sociology of Modernity. Liberty and Discipline[END_REF].

historically conceived and operationalized through a variety of cognitive artifacts, disciplining devices, and technologies to support the construction of both the public sphere and the individual. According to this construction, in order to be publicly justifiable, a mode of valuation must rest on a universally legitimate underlying good, meaning that this good must potentially benefit humanity as a whole: a truly "common good." This beneficial link must be proven on the basis of a specific form of knowledge: modern scientific knowledge. The experience of value relevant for this public mode of valuation must be formalized in such a way that reason, as conceived since the Enlightenment, can critically reflect upon it. This implies that this experience of value must be independently valid beyond the unique context of its occurrence.

For the purpose of the present argument, I will limit myself to pointing out that, according to this understanding of publicness, a public mode of valuation precludes a direct, sensorial, incontext experience of the good. The validity and indeed the value of such an experience must thus be proven in a way that can stand up to critical scrutiny, through a formalization in terms of objective experience. Moreover, the key operation that has to be performed in order to justify a publicly valid value judgment is that of establishing objective equivalence across different situations; this requires the devising of tools and techniques of commensuration. In this sense, commensuration can be considered as a social process [START_REF] Espeland | Commensuration as a social process[END_REF]. Commensuration materializes in socio-technical "investments in forms" [START_REF] Thévenot | Rules and implements: investment in forms[END_REF]) meant to ensure the formatting of things that are different (in the personal experience that one has of them) into things that can be represented as the same (in value).

The investments in forms needed to stabilize these public modes of valuation require the highest degree of temporal and spatial validity in the formatting of knowledge (universal validity). They require substantial material transformations as well, accounting for the persistent material impact of these investments and their limited opportunities for reversibility [START_REF] Thévenot | Governing Life by Standards: A View from Engagements[END_REF].

A mode of valuation based on emplaced experience, or emplaced mode of valuation, is diametrically opposed to this former public one. 5 By the adjective emplaced I refer here to a form of knowledge and appreciation that takes place primarily at the aesthetic level, 5 As discussed by Sarah Pink (2009:27), the emergent "paradigm of emplacement" points to "the revision of the notion of embodiment to account for the situatedness of the knowing body as in biological progress as part of a total environment." The origins of this approach lie in the "phenomenology of place and space" developed by authors such as the philosopher Edward Casey, the geographer Doreen Massey and the anthropologist Tim Ingold. I argue that through the ROE framework, it is possible to articulate this phenomenological account of the experience of the environment with a sociological theory of action.

understood as the level of perception and corporeal sensibility. Following Thibaud (2012:4) the term "aesthetic" has to be intended here "in its original meaning of aesthesis, i.e., perception by the senses and not only as judgment of taste or philosophy of beauty." This mode of valuation could be defined as "esthetic" but two reasons justify the choice for "emplaced valuation": the more explicit link to the material conditions of valuation and the more direct connection with the critical and political potential of this mode of valuation. The key evaluative operation here is not that of establishing objective equivalence, but rather of appreciating a personally (and bodily) felt proximity to a personally (and bodily) felt good. At work here is a form of appreciation that can be communicated to others but in forms less amenable to being generalized, in the sense that they can be neither depersonalized nor decontextualized: an emplaced good can only be experienced through the senses in a given situation.

The ROE literature emphasizes the variety of emplaced modes of valuation people routinely deploy, but which are generally glossed over within the social sciences. Examples of "emplaced goods" guiding valuations include : the "ease" of the "familiar engagement" with the environment [START_REF] Breviglieri | L'espace habité que réclame l'assurance intime de pouvoir: Un essai d'approfondissement sociologique de l'anthropologie capacitaire de Paul Ricoeur[END_REF]; the "excitement for the newness" of the exploratory engagement [START_REF] Auray | L'exploration comme modalité d'ouverture attentionnelle. Design et regulation d'un jeu freemium[END_REF]; the resonance felt while engaging with the environment through attuning to an "ambiance" [START_REF] Thibaud | A sonic paradigm of urban ambiances[END_REF]. When they haven't been seen as the source of various dangers or impediments to the expression of "modern values," these modes of emplaced valuation have been considered as "tacit" or "practical" and are automatically disregarded as a potential source of critique.

Emplaced and public modes of valuation often confront one another in a public setting.

Where each mode is put forth as the most appropriate way to assess the value of an environment, we can speak of situations of "radical incommensurability" [START_REF] Centemeri | Reframing Problems of Incommensurability in Environmental Conflicts Through Pragmatic Sociology: From Value Pluralism to the Plurality of Modes of Engagement with the Environment[END_REF]. It is important to note, however, that actors can resort to a wide variety of local modes of valuation, neither properly public nor emplaced. In this latter case, the relevant value experience is not meant to be universally valid -as is the case with the public mode -but neither does it depend entirely on the sensuous, personally experienced body-environment nexus, as in the more phenomenological rendering of emplaced modes. Rather, local modes of valuation can rest on the creation of a (more or less extended) local space of equivalence or on references for valuing that emerge from a (more or less extended) community of experience. A form of bounded generalization is at work here, tied to some contextual conditions that have no ambition do be universally sharable and publicly legitimate, but nevertheless call for an evaluation of actors' experiences from the standpoint of a form of local common good.

When approaching situations of conflict and disagreement from the analytical perspective of the plurality of modes of valuation, it is not sufficient to pay attention to how actors refer to justifiable orders of worth in order to denounce injustice [START_REF] Boltanski | De la Justification[END_REF]. It is necessary to take into account the variety of ways in which actors produce "arguments" concerning the legitimacy of what should be considered as valuable in a given situation and how they succeed, or fail, in gaining wider support for their positions. In these argumentations, modes of valuation -be they public or otherwise -come to be combined in novel ways. In order to grasp the contours of the debates at the frontier between the legitimate and the illegitimate, it thus becomes necessary to further unpack these emergent articulations of arguments.

In the following section, I analyze the transformations of the arguments deployed both by supporters and opponents of the Malpensa airport expansion programs, paying attention to the ways in which they combine public, local and emplaced modes of valuation of the environment. This qualitative analysis is based on several sources of data: ten semi-structured interviews I conducted with activists, political actors and experts involved in the Malpensa case, as well as supplementary data in the form of official documents (including technical reports), materials produced directly by the mobilized groups (including web contents), press articles (300 articles published in the main Italian national journals from 1998 to 2012) and web articles (from web journals and activist blogs). 6 Previous academic and non-academic works of synthesis on the Malpensa case [START_REF] Balducci | L'implementazione di grandi progetti pubblici. Una indagine sui processi decisionali relativi all'ampliamento dell'aeroporto della Malpensa e alla rilocalizzazione del Policlinico di Milano[END_REF][START_REF] Pizzi | [END_REF][START_REF] Di | Dossier Malpensa[END_REF] have been particularly helpful, especially for reconstructing the earliest phases of the conflict. The methodology I have applied is in line with the "pragmatics of protest" approach developed by Francis Chateauraynaud (2011[START_REF] Chateauraynaud | Environmental Issues between Regulation and Conflict[END_REF]. The pragmatics of protest is defined by the author as "an attempt to bring together argumentative analysis of public issues and sociology of practice in different arenas or 'interacting milieux'" (Chateauraynaud 2015:2).

Consequently, I observe how actors combine different modes of valuation of the environment in their "arguments," while at the same time paying attention to the ways in which actors interact in the contexts of action and conflict. According to this approach, the strength of an argumentation is not simply based on intellectual coherence: it has to do with the success in creating a disposition to act, through a connection with an experiential "substrate." In this sense, an argument always relies on a plurality of modes of valuation.As I will show, arguments evolved alongside specific action repertoires and social and sociotechnical imaginaries, including social understandings of the environment as a matter of political concern.

The struggles against the Malpensa airport expansion and the transformations of environmental critique

The Malpensa airport is situated approximately 50km northwest of the city of Milan, the regional capital of Lombardy. Managed by SEA(Società Esercizi Aeroportuali), a joint stock company controlled by the Municipality of Milan, the airport occupies a surface area of 1.220 hectares at the border between the regions of Lombardy and Piedmont. With two terminals, two runways, and a dedicated cargo terminal, in 2015 Malpensa handled the second largest volume of airport passenger traffic in Italy (more than 18 million passengers) and was ranked first in the country in terms of freight transport volume. 7The airport site stretches over the territory of the Lombardy Regional Park of the Ticino River Valley, created in 1974 as the first Regional Park in Italy. In fact, regions in Italy exist as politico-administrative entities since 1970, when the first regional elections were held. The municipalities of the Ticino Valley, together with an environmental NGO called Italia Nostra (Our Italy), had supported the development of the park since 1967. Around this same time, however, in 1970 SEA submitted its first master plan for the expansion of the Malpensa airport to be considered by national authorities. The plan -known as the "Big Malpensa"proposed the creation of a third runway in addition to the already existing two. Its subsequent approval in 1972 triggered what would come to be a decades-long battle over airport expansion; this legacy of conflict and controversy continues even into the present day.

In the rest of this section, I trace the evolution of this lengthy conflict, identifying three distinct phases corresponding to as many proposed expansion plans. With each new plan came (1) a correspondingly unique formatting of arguments deployed by actors supporting and opposing the plan and (2) specific action repertoires rooted in the evolution of underlying imaginaries, which were connected to major socio-political changes occurring in each respective period.

From the "Big Malpensa" plan to the "reasonable" expansion: mobilizing for the right to participate (1972-1987)

In the arguments supporting the first plan to expand the airport, SEA positioned itself as a major contributor to the modernization of the national infrastructural system -so as to support economic development -while affirming its own leading position in the national civic aviation industry. By way of the massive economic investments it required, a central ambition of the expansion project was to secure SEA national and international renown in the civic aviation industry. Public modes of valuation are articulated with local "objective" needs (an expected increase in air traffic) in tandem with the local business interests of SEA. It is important to notice that SEA has progressively developed a business expansion strategy based not only on airport business, but also on real estate investments (Beria and Scholz 2010, 72).

These arguments point to an imaginary of a modernized Italy, run by a modern technocratic élite and integrated into international networks of exchange.

However, the promoters of the expansion were confronted with opposition by the municipalities whose inhabitants stood to be directly impacted by the plan, and who were backed up by a large coalition of civil society actors, including trade unions, social movements, environmental NGOs, and grassroots movements. This composite coalition organized demonstrations and public assemblies, publicized their critiques through press campaigns, produced counter-expertise on the potential health damages of the expansion, and succeeded in creating a diffuse mobilization.

Different social demands were combined together into "chains of equivalentially related elements", what Ernesto Laclau defines a "populist form of politics" (Griggs and Howarth 2008:128). In the Malpensa case, this populist logic entails a twofold argument. On the one hand, there is the denunciation of the generalized lack of public participation in all kinds of decision-making processes. As with other similar cases of protest in Europe and North America during this period, critique in the Malpensa case was based on the "right to participate" [START_REF] Feldman | Air Transportation Infrastructure as a Problem of Public Policy[END_REF]. On the other hand, there is an argument based around the refusal of a capitalist driven type of local development. Equivalence is argumentatively (not objectively) built between two forms of exploitation: the capitalist exploitation of workers, and the exploitation of the environment. Equivalence is also built between two experiences of the environment: the experience of workers in their working environments, and the experience of inhabitants in their everyday living environments. Here, the environment is conceived of as the place where local communities had been organizing their daily activities in such a way as to produce a certain quality of life, to which basic rights were attached; this included the right to health, something that many social movements active during this period emphasized in their struggles for the right to healthy working conditions [START_REF] Barca | On working-class environmentalism: a historical and transnational overview[END_REF].

Considered as a basic requirement for health, the citizens' defense of and claims to maintaining a certain quality of the everyday living environment was partially built on the importance attributed to emplaced modes of valuation of the environment. The idea was that of rehabilitating the person and her experience as fundamental arbiters of the relevant knowledge required for public decision-making. For this purpose, politically engaged experts who were closely allied with leftist parties in the region were collaborating directly with workers and citizens in order to co-produce a form of counter-expertise emanating from the embodied and emplaced experience of health. These arguments against the Malpensa expansion plan were linked with an imaginary of a more just and democratic society and a common struggle of citizens and workers united against capitalist exploitation.

Faced with the energy crisis of 1974 and the delay of the central government in making funds available for the airport expansion, SEA decided to revise the "Big Malpensa" project, dropping the idea to build a third runway. It is at this point that the newly elected regional government decided to intervene.

The intervention of the regional government contributed to the emergence of what Laclau defines as an "institutional form of politics", according to which social demands "are registered and processed by an existing political authority in a singular and punctual fashion" (Griggs and Howarth 2008:128). In 1979, the regional government created the Comitato interassessorile allargato per i problemi di Malpensa (Inter-council Enlarged Committee for the Malpensa Problems), an oversight body which saw Regional Council members, the president of the Ticino Park, and mayors from the municipalities that were to be affected by the expansion coordinate with each other in the work of verifying and evaluating the consequences of the alternative plans of expansion.

Although the committee resulted in a series of meetings, there was no collective ambition for it to become a permanent structure for monitoring and evaluation. Rather than basing agreement on a formalized comparison of alternative options (including the no-airport option that was never considered), there was instead a convergence toward a consensual yet still relatively vague idea of "reasonable and controlled expansion" of Malpensa. The result resembled less a "public compromise" between multiple actors' competing visions of the "good" [START_REF] Boltanski | De la Justification[END_REF] but was rather more akin to a "private arrangement" where actors' local needs were sufficiently addressed for their immediate purposes (cf. Stark

2009).

This culminated in a new, second expansion plan put forth by SEA, called "Malpensa 2000."

The Lombardy region approved the plan in 1986 and stipulated a number of constraints. In particular, the volume of air traffic expansion was to be limited to 12 million passengers per year.

Meanwhile, the expected economic benefits from airport activities progressively became a central part of proponents' arguments justifying the need for expansion. This was largely driven by the economic turmoil that the Malpensa region was facing as a result of a deindustrialization process that had begun in the 1980s. The territory between Malpensa and Milan (the so called "Alto Milanese") was eventually included in the list of beneficiaries of the Objective 2 European structural funds, to support industrial and structural change (Tosi and Vitale 2011:7).

Europe was meant to become an important actor in the Malpensa case, especially by way of the directives and treatises through which European environmental policy had been progressively shaped. In particular, in 1985 the European Directive 85/337/EEC introduced the legal obligation of the Environmental Impact Assessment (EIA) procedure for all projects deemed to have significant impacts on the environment -including airports. In a more general European context, European Directives 8 can be seen as an important tool for institutionalizing a "green worth" [START_REF] Lafaye | Une justification écologique? Conflits dans l'aménagement de la nature[END_REF], contributing to the stabilization of public qualifications (of objects and entities) and tests of reality meant to operationalize an ecological understanding of the value of the environment. The efforts to create this publicly legitimate sphere of "green value" is linked to the emergence of the sustainable society as a new imaginary that was gaining ground during this second phase of Malpensa expansion plan.

Yet due to the specific conditions under which the EIA directive was implemented in the Italian setting, the Malpensa 2000 plan was not ultimately submitted to a formal procedure, creating a space for contesting the plan on legal grounds. Together with the inclusion of Malpensa 2000 in the list of "priority projects" of the Trans-European Networks-Transport (TEN-T) , this would trigger a new phase of social mobilizations. 9 8 See in particular the "Habitats Directive" (Directive 92/43/EEC) that, along with the "Birds Directive" (Directive 79/409/EEC modified by Directive 2009/147/EC), led to the creation of the European Network of protected sites "Natura 2000." 9 The Trans-European Networks (Transport, Energy, Telecommunication) are the strategic infrastructures whose realization is considered as crucial for improving market circulation and socio-economic cohesion in the European Union.

The increasing relevance of expertise in the opposition to "Malpensa 2000": denouncing the expansion as illegal (1993-2008)

In 1994, the Italian government of the newly elected Prime Minister Silvio Berlusconi, supported by a coalition of right-wing parties, requested that the Malpensa 2000 project be included on the list of priority projects of the European TEN-T. The Milanese airport was promoted as a potential international aviation "hub" for Southern Europe, 10 even if its expansion under the Malpensa 2000 plan was limited to the "reasonable" maximum volume of 12 million passengers annually, far below the threshold that would qualify it as an efficient hub. In addition, considering that Italy already had a hub in the airport of Roma-Fiumicino, the government's demand to include Malpensa in the TEN-T was seen by many as a controversial move.

The arguments supporting the expansion of Malpensa as a hub were propelled by its being framed as a strategic infrastructure for Italy -especially for northern Italy -and the promise it held for facilitating economic competition at the European and global levels. Moreover, the investments related to the airport, and the airport itself, were purported to bring economic growth to the Malpensa region. Potential ecological damages were acknowledged, but were considered as compensable, not simply with the usual economic means but in ecological terms as well (e.g. through the creation of green corridors and reforestation efforts).

There was, however, no formal evaluation concerning the feasibility and the effectiveness of such ecological compensations; nor was the expansion project subjected to any serious comparative scrutiny, either in terms of the socio-environmental impacts or the economic potential of alternative project proposals.

Among the new supporters of the Malpensa expansion during this phase was the very Lombardy Region that was initially supposed to guarantee a reasonable and controlled expansion plan. Moreover, the rivalry with the main airport hub in Rome fit perfectly with the "Northern question" narrative of the right wing separatist political party Lega Nord that was now included in the regional government coalition.

The left-wing government of the Prime Minister Romano Prodi, who succeeded Berlusconi in the elections of May 1996, guaranteed the same level of support for the hub project as it had enjoyed from the previous administration. This reflects the strength gained in the last twenty years by an "ideology of big infrastructures", that is, the bi-partisan support to a 10 A "hub" is, for an airline, the airport that functions as operational basis and where all flights are routed through to get people transferred to their final destinations according to a hub and spoke model, which is alternative to the point-to-point model. sociotechnical imaginary according to which large-scale infrastructure projects in Italy are the main drive for economic growth [START_REF] Berta | Una TAV per partito preso[END_REF][START_REF] Caruso | Theories of the Political Process, Political Opportunities Structure and Local Mobilizations[END_REF].

Meanwhile, local opposition was growing stronger, with various actors, institutional and otherwise, becoming involved: the Ticino Park, the municipalities of the Piedmont side of the river (excluded by the negotiations with SEA up to this point), national environmental NGOs, the Green Party, as well as numerous grassroots movements (federated as UNICOMAL in Lombardy and COVEST in Piedmont).

The main arguments against the expansion during this phase of struggle were its illegality (e.g. the lack of EIA procedures) and the risks of health and environmental damages. The production and diffusion of expertise to support these public modes of valuation was considered as the more appropriate action repertoire, together with public demonstrations and protests. It is important to note that activists conceived their production of expertise as a way to contribute to a better decision-making process. Their motivation was thus to increase the quality of the public debate and to fight against what was perceived as being the capture of public institutions by private interests. Their imaginary was not that of a radical shift away from the hegemonic logic of the capitalist system, but rather that of a participatory democracy that would provide for greater transparency and a more (environmentally) sustainable society.

The mobilization expressed an "institutional-bound type of politics" [START_REF] Griggs | Populism, Localism and Environmental Politics: the Logic and Rhetoric of the Stop Stansted Expansion campaign[END_REF], in which the reasons to mobilize against the airport were not related to broader social and economic struggles but to localized controversies concerning specific aspects of the project.

Moreover, the aforementioned lack of formalized procedures of evaluation implies that instruments for decision-making were indeed supported by activists as means for turning a very opaque process into a testable procedure, open to critique. Yet they also required the activists to delve into highly technical matters, resulting in a progressive "technical alphabetization"11 of activists, raising the threshold of access to participation, and leaving public demonstrations as the only other alternative format of involvement in the struggle against expansion.

In fact, the opposition organized a series of demonstrations and sit-ins that blocked access to the airport as well. These demonstrations were mainly the expression of individual citizens' exasperation. In fact, to give an idea of the impact of the airport expansion and traffic load, in 1998 Malpensa was still registering 5.5 million passengers annually (more than 73 thousand flight movements) while only a year later, in 1999, the passenger volume reached the threshold of 17 million (more than 220 thousand flight movements).

In June 1998, the mobilization succeeded in convincing the Minister of the Environment to submit the Malpensa 2000 plan to a formal EIA. A series of local public assemblies were organized at the behest of environmental NGOs and grassroots movements. Experts in the EIA procedure were invited to participate and to share relevant knowledge with local inhabitants so that they could better understand the procedure and thus be able to meaningfully participate in the evaluation process. The relationship between experts and the public during this phase of opposition appears to accord more with the paradigm of the "deficit model" [START_REF] Irwin | Science and Its Publics: Continuity and Change in the Risk Society[END_REF] than the practice of co-production of knowledge promoted during the first phase in the 1970s. The emphasis on the everyday personal experiences of the environment as a source of knowledge and emplaced value was partially put aside, and they were brought in only if they could be related to a provable health problem or instance of environmental damage.

In November 1999 the Environment Minister closed the EIA procedure with a negative evaluation, requesting a suspension of any further expansion of air traffic at the Malpensa airport. At once defying this evaluation and request, and reaffirming the strategic role of this infrastructure, Prime Minister Massimo D'Alema issued a special decree (DPCM 13 December 1999) allowing further expansion.

Another eight thousand people demonstrated against the "illegality and abuse" of the airport in May 2000, but by November of the same year, when a new demonstration was organized, citizens' participation began to wane significantly, revealing a growing resignation and distrust.

Against the third runway: building a place-based resistance through practices of care (2008-2014).

In 2008 SEA announced plans for a new 330 hectares expansion of the airport, including the construction of a third runway, a new terminal, and the expansion of the "Cargo City," the area equipped for storing goods and hosting commercial facilities. One argument supporting the third runway was the need to find a solution to reduce the noise impact -ironically brought about by the expanded passenger traffic allowed for in the previous phase of expansion -through a better distribution of take-off and landing patterns. At the same time, an additional reason for supporting the expansion was the approaching mega-event of EXPO 2015 in Milan, which was sure to increase the number of individuals flying to the area in the not so distant future. The expansion is thus presented here simply as an efficient answer to objective local needs.

In 2010 the SEA master plan was approved by the Italian regulation agency for air transport (ENAC) and submitted for EIA. A large variety of actors -including the Ticino Park, environmental NGOs, grassroots groups, individual citizens, municipalities, and the Piedmont and Lombardy Regions -sent more than 2,000 negative remarks on the SEA document to the Ministry of the Environment during the course of the EIA procedure. 12 It was a resounding success for the opposition in terms of participation and amassing additional evidence of the process of "technical alphabetization" of local movements that occurred during these years of struggle. Behind this successful mobilization, however, there was the coordination effort deployed by a new grassroots movement: Viva via Gaggio ("Hurrah for Gaggio Road," or VVG).

The group is named for a small country road, called the Gaggio Road that passes through a green area, known locally as the Gaggio Heath. Heaths are specific ecosystems -especially rare in Mediterranean climates -which are included in European Habitats Directive, a list of valuable ecosystems and species that European Union member states are directed to protect.

The Gaggio Heath, however, holds no special status as an officially protected area.

The Gaggio Road has been known locally as a place for walking, jogging, biking, enjoying nature, and relaxing. The VVG group has progressively transformed it not simply into a symbol of struggle but into a vibrant place where the resistance against the expansion takes a new shape: that of practices of environmental care. In the 40-year history of attempts to expand the Malpensa airport, this most recent phase is the first time that the environment under threat is clearly identified with a specific place whose value is expressed through an argument revolving around local attachments to that place and the everyday practices of care that valorize it.

The Internet, and especially social networks are key instruments of the VVG's communication strategy. Through the sharing of photos and videos, of poems and songs, the personally experienced and emplaced value of the Gaggio Road is communicated to a larger community. Various "proto-instruments" (Callon and Rabeharisoa 2003) enable VVG to share this particular way of attributing value to the environment of the Gaggio Road with others.

The VVG group is not active exclusively on the Web; they organize strolls and promenades in the Gaggio Road, which is presented as if it were a person. The road has feelings, an identity, a past: it is "one of the family", "a relative that we need to protect." A reference to indigenous cultures is included to prove the universality of this experience of attachment to a place.

According to the VVG group, the previous struggles against the airport tended to overshadow the reality of the environment as a place of attachments, and to turn it into a passive victim, the lifeless scene where damages occur. The group considers this as a victory for the planners of the airport expansion project. For this reason, VVG does not organize any demonstrations at the airport site; instead, it organizes its activities just outside the airport fence in order to show evidence of a lived-in and loved environment that perseveres against all odds. The emplaced experience of the environment is put forward as a largely shareable experience, one in fact shared by the "Gaggio people." People are invited to "come and meet the Gaggio Road" and to "stay close as much as possible to our loved one (il nostro caro)" -where the "loved one" is the road and its environment -"who is threatened." As is the case with a close friend or a "loved one", the "true" value of the Gaggio Road is considered as deriving from the establishment of an intimate bond or connection with the road as a specific place.

Emplaced modes of valuation are considered as fundamental to judge the "true" value of the Gaggio Heath. Still, this value experience potentially introduces a condition of radical incommensurability, meaning by this the impossibility of judging the value of the Gaggio Heath through the establishment of equivalences with other valuable places [START_REF] Centemeri | Reframing Problems of Incommensurability in Environmental Conflicts Through Pragmatic Sociology: From Value Pluralism to the Plurality of Modes of Engagement with the Environment[END_REF].

For the VVG activists, however, it is important to work on both fronts of valuation: proving the value of the heath according to justifiable definitions of worth in a public setting and nurturing local, familiar attachments and other modes of emplaced valuation as a specific way to value and valorize.

Elements of both populist and institutionalist politics are thus detectable in VVG's novel brand of activism, together with the limited capacity (and a partial unwillingness) of the group for connecting the Malpensa local struggle with other similar and more politicized struggles.

There is a certain reticence to put forward arguments pointing to the need for a radical change in society, as when airport activities are denounced most typically for their impact on climate change issues [START_REF] Griggs | The politics of airport expansion in the United Kingdom. Hegemony, policy and the rhetoric of 'sustainable aviation[END_REF]. At the same time, this discursive elision is supplanted by those very practices that encourage individuals to forge a personal connection to the place, connections that are themselves conceived as a material instantiation of radical change. Yet when inviting people to grow a special connection with the Gaggio Road, the VVG activists are promoting an idea of attachment to a place that has little to do with the links established between place and identity such as those proffered by the Lega Nord party and in line with the reactionary proposals of many other contemporary right wing movements.

The VVG denounces Lega Nord -which promotes itself as being "close to the territory" while supporting the Malpensa expansion plan -for espousing a vision of territory as a resource to be exploited and of community as an abstract entity with no grounding in common practices of taking care of the environment.

The "Gaggio community" is, to the contrary, conceived of as a community in constant evolution. The VVG group organizes a variety of activities to bring new people to "meet" the Gaggio Road. These activities are conceived primarily as sites of conviviality, propitious to a certain personal and collective experience of the place. People are invited to be not simply users or visitors of the Gaggio Road; rather, they are encouraged to create a personal and affective bond to this place. Prior to the demand of mobilizing against the airport, people are offered the opportunity to develop a specific "place awareness" [START_REF] Magnaghi | Il progetto locale. Verso la coscienza di luogo[END_REF], through the emplaced experience of the value of the environment. These activities can thus be conceived as a form of what Noortje Marres (2012: X) has called "material participation", that is a mode of engagement in which "everyday material actions are put forward as useful and valuable operations upon matters of public concern."

These activities run in parallel with other initiatives, commonly undertaken by grassroots movements when contesting big infrastructures, which are meant to publicly display the value of an environment. The category of "local heritage" is frequently mobilized for this purpose alongside an understanding of value in terms of biodiversity. In both cases, the general categories of "heritage" and "biodiversity" are declined according to local modes of valuation, in which the reference to a legitimate order of worth (domestic, green) is combined with the recognized importance of more contextual sources of value.

However, the purpose of the VVG group is not limited to protecting the Gaggio Road as heritage properly speaking. What the VVG group conceives as the "real" challenge is to bring local people to believe in the possibility of an alternative socio-economic model of development for the territory, based on activities that are not just respectful of the environment but that are connected to the specific history and ecology of the place. A new emerging social imaginary is detectable here, that of a local community that reintegrates its choices of development in a web of socio-ecological interdependencies.

Critique and social change: a discussion of the Malpensa case

In this section of the paper, I rejoin the discussion introduced earlier regarding the interplay of critique, modes of valuation, and social change in the Malpensa case. More precisely, I zoom in on the role that emplaced modes of valuation play in this dynamic.

In the first phase of the conflict, the mobilization against the expansion expresses an understanding of the environment both as a "matter of concern" (Latour 2004) according to public justifications, but also as an everyday place of living whose quality is assumed as a general precondition for the full enjoyment of social rights, the right to health foremost among them. Even if valuations of the environment based on social justice and democracy are put forward as the central critical arguments to create equivalences between various struggles, modes of emplaced valuation are recognized as the source of specific knowledge and value experiences endowed with critical potential. In particular, the importance attributed to the coproduction of knowledge through the collaboration of citizens and engaged experts, points to the relevance attributed to emplaced modes of valuation in the production of critical knowledge. The capitalist organization of economy and society is denounced as threatening not simply environmental values but also the more general possibility of a meaningful experience of living and working in one's own place. The defense of this place is part of a larger struggle to promote a change in the politico-economic system and this specific composition of modes of valuation takes "expressive power" [START_REF] Chateauraynaud | Environmental Issues between Regulation and Conflict[END_REF] thanks to a social imaginary of radical change in society. During the 1970s, this imaginary was indeed quite widespread, and was made manifest in the Malpensa case by the leftist political parties and social movements that mobilized in the struggle against expansion.

The Malpensa case shows that when confronted with this critique, public actors answered through "internalizing externality" or "framing overflowing" [START_REF] Callon | An Essay on Framing and Overflowing: Economic Externalities Revisited by Sociology[END_REF]: the "environment" is progressively structured as a specific sphere of institutional action, equipped with qualifications, categories, tools, and instruments. If we define environmental critique in terms of a form of contestation of the hegemonic socio-economic order aimed at producing a change in the role that nature plays in the political community, this change appears, in the externality frame, as an incremental or reformist change, through the institution of an environmental sphere of public action as complementary to the economic and social spheres.

The idea of overlapping spheres inspires the new imaginary of the "three pillars" model of sustainable development, relying on participatory democracy, epitomized in the Malpensa case by the fragile arrangement known as "reasonable expansion."

The second phase of the mobilization is triggered by the institutional betrayal of the promises made under the reasonable expansion scheme. Compared with other cases of struggles against big infrastructures, this betrayal takes a quite patent form in the Malpensa case. The lack of formalized procedures of evaluation of the Malpensa 2000 master -whether impact analysis cost-benefit analysis -is an easy target for a reformist critique that conceives of conflict as a way to increase the quality of public decision-making in order to turn sustainable development into the reality of actual public choices.

Where elsewhere critique is confronted with the hard task to show the inner biases of such procedures as EIA and CBA in underestimating environmental values [START_REF] Costa | The Building of a Dam: Value Conflicts in Public Decision-Making[END_REF], in the Malpensa case activists actively promote the adoption of these formal procedures of evaluation as a way to create the conditions for an open public debate on the issue of expansion. However, the denunciation of the second phase of proposed expansion on the grounds of its illegality ultimately comes up unsuccessful when confronted with the cohesion existing within political and entrepreneurial elites in promoting economic growth as an overarching, undisputable common good. In this frame, the considerations of the actual relations between economic growth and social and environmental justice are subtracted from open political debate and public scrutiny. The objective of economic growth implies the subordination of issues of social and environmental justice to a specific form of objectivity that implicitly assumes that all modes of valuation can be, and indeed should be, expressed in monetized terms. This introduces a significant restriction on the conditions under which a mode of valuation is deemed legitimate in public debate, and it has major consequences for the social visibility of the existing plurality of other (non-economic/non-quantitative) modes of valuing the environment.

The magnitude and direct experience of the effects of the economic crisis equips the argument of growth with expressive power, especially at the level of national debate. In fact, this second phase of the struggle is marked by a national and European echo that nevertheless fails to bring the Malpensa movement to connect with other similar national or international struggles against large infrastructure projects. The mobilization is in fact privileging a logic of difference (even exceptionality) over investing in creating equivalences with other struggles.

The capacity to produce legitimate expertise on health and environmental damages is considered of paramount importance. In this phase of the conflict the mobilization relies primarily on public modes of valuation of the environment, especially green and civic valuations. This explains the importance afforded to expertise and to experts transmittingrather than co-producing -relevant knowledge to citizens. This critique is not successful in challenging the pro-expansion arguments and imaginaries of growth and global competition, which show a significant stability over time and impermeability to wider social demands. This undeniably induces discouragement and even fatigue amongst many of the actors who had mobilized against expansion, and yet the mobilization does meet some success: in producing technical alphabetization amongst activists, and also in reinforcing the local networks of the various actors opposed to the expansion. Even if the mobilization does not achieve its objective of preventing the expansion from happening, this phase of critique acts as a means for nurturing resilience by way of keeping afloat a commonly held sense of injustice and illegality and fostering a basic sense of political community.

In the last phase of the conflict, the action of the VVG grassroots movement is primarily oriented towards restoring a "popular" (and positive) dimension of participation to a common endeavor, as a way of relaunching critique albeit in a rather novel form. Recovering this popular and positive dimension of participation, as complementary to the commonly held feelings of injustice within the local community, requires innovations in modes of valuation and action repertoires. In particular, emplaced modes of valuing the environment are put forth in the shape of "material participation." I argue that this focus on practices as a form of participation is meant to promote the legitimacy of emplaced modes of valuing the environment in public debate, and also as the source of a radical critique of those definitions of environmental values that facilitate simple commensurations and render risks and damages inherently compensable. Through this form of material critique, a different kind of resilience is thus nurtured, one that accompanies the emergence of an emplaced resistance. With this term, I point to a certain material transformation of the environment, especially through practices of environmental care that generate progressively, through its own material characteristics, a material incompatibility with the project of the airport expansion. More generally, through emplaced resistance, activists support an understanding of the local community as part and parcel of a web of socio-ecological interdependencies. This ecological imaginary of the local community dovetails with an understanding of the local condition as part of a larger system of interdependencies, thereby potentially helping actors to construct argumentative equivalence between social demands. In this sense, in what I call emplaced resistance, localism and the populist logic of mobilization (in Laclau's sense) are not necessarily mutually exclusive but rather work to reinforce one another. 13 The mobilization of emplaced modes of valuation is not seen to be an inherent obstacle to the construction of argumentative equivalence between dispersed social demands, since these modes point to a common form of experience of the value of the environment based on sensorial appreciation. However, they do introduce a form of radicalism, in that they fundamentally defy a certain modern understanding of legitimacy as regards modes of valuation. In this sense their mobilization in critical arguments aims to challenge the traditional contours of legitimacy, concerning what should count as valuable in public decision-making, and thus bringing to the fore the request of some radical social change. In the Malpensa case, this radicalism is somewhat tempered by the more institutionalist logics of action that the mobilized coalition promotes, and to which the VVG group contributes as well. At the same time, the VVG group actively works to increase the reflexivity of the local community in regards to the many values of the environment, thus laying the groundwork for the emergence of a common will that seeks to challenge the acceptability of a generalized compensatory logic when dealing with environmental issues.

Concluding remarks

The Malpensa case has many similarities with other cases of contested big infrastructure projects in Europe, even if the struggle against the Milanese airport expansion has remained somewhat isolated and, especially in its most recent phase, preeminently local, mostly for the unwillingness of the mobilized actors to openly join forces with other networks of local struggles that are perceived as politically too radicalized.

Since 2010, a European movement against "unnecessary imposed mega projects" has in fact begun to unfold. The struggles against the airport of Notre Dame des Landes in France [START_REF] Kempf | Notre-Dame-des-Landes[END_REF], a mining project in Rosia Montana, Romania [START_REF] Velicu | Undoing environmental justice: Re-imagining equality in the Rosia Montana anti-mining movement[END_REF], and the high speed rail project Turin-Lyon in Italy (Caruso 2010, Della Porta and[START_REF] Porta | Le ragioni del no. Le campagne contro la TAV in Val di Susa e il Ponte sull Stretto[END_REF] have all become iconic cases of this emerging radical environmental critique.

While the Malpensa case is not one of these paradigmatic examples of environmental struggle, I argue that it nevertheless shares with them the importance progressively attributed to material participation as the expression of an emplaced resistance emanating from a "politics of place perspective" (Harcourt and Escobar 2005;[START_REF] Harcourt | The future of capitalism: a consideration of alternatives[END_REF]). Here, "experiences in place" -and, I would add, especially emplaced experiences of the value of the environment -are of fundamental importance in thinking and practicing a truly sustainable ecological organization of social life.

In my discussion of the VVG group's actions, I have stressed the importance of its collective attribution to the "emplaced experience" of the environment the source of modes of valuing that are considered paramount to understanding its "true" value. The importance attributed to the emplaced experience of the environment in the definition of the environmental values that should count in the decision-making processes is common to many of the emblematic struggles against big infrastructures I mentioned above. The physical occupation of the spaces under threat, the importance of conviviality, of sharing everyday activities (from cooking to growing vegetables) are all ways to prove that these spaces are, in fact, lived-in and loved places.

To stress the importance of the emplaced experience of the environment is not just a strategy these groups mobilize in order to reanimate public participation through appealing to "affective loyalties".14 Rather, emplaced modes of valuing are shared in communities of practice, and they are conceived as a powerful, inexhaustible source of critique against the restricted and oppressive definitions of what should count as legitimately valuable in the current capitalist order. The generalized commensurability of values sought after through the spreading of economic valuation to all realms of life stands in stark contrast to emplaced value experiences, which are a primary resource for arguing for radical incommensurability.

As we have seen in the Malpensa case, beginning in the 1990s, what characterizes the newly emerging modes of governing in Italy is the predominance attributed to the convergence of economic utility together with market competition as the most (and perhaps sole) legitimate arbiters of value in all aspects of social life. The progressive impoverishment of the public understanding of the common good and the exhausting, never-ending debate over data and expertise to which politics is progressively reduced have led to a rediscovery of everyday life practices and the places in which they occur. These are fundamental political loci for exploring and "prefiguring" [START_REF] Yates | Rethinking Prefiguration: Alternatives, Micropolitics and Goals in Social Movements[END_REF] alternative socio-ecological organizations.

From a question of value pluralism, environmental critique thus exhibits a progressive shift towards questions of ontological "multiplicity," to signal the coexistence of modes of valuation of the environment that rest on not quite fully equivalent languages and materialities [START_REF] Blok | Pragmatic sociology as political ecology: On the many worths of nature(s)[END_REF]. Besides protest, the issue at stake here is to materialize an alternative and to materially produce a "crack" in the socio-ecological order (Bresnihan and Byrne 2014).

However, as I pointed out in the case of the VVG group, it is important to distinguish the community of practice as envisioned by these activists -a vision based on taking care of a specific environment -from the community in which a stated identity, disconnected from such practices, gives title to claims for a special connection to a given place, as in the case of the Lega Nord activists. The form of commonality at stake in groups such as the VVG is thus neither that of a "community" identified in terms of territorial, social or ethnic characteristics, nor that of an abstract "public." Indeed, my analysis -as a detailed accounting of the modes of valuation that actors mobilize in collective action -makes such a difference visible, while also calling attention to the analytic import and utility of drawing out this distinction.

To conclude, I would like to stress the contribution that pragmatic approaches can provide to the understanding of critique and of its transformations over time and space. In particular, I argue that pragmatic tools can be usefully mobilized to support socio-historical analyses of the transformations of modernity and critique that pays attention to the spatial-temporal contexts in which human life unfolds.

As pointed out by Wagner (2001:24), such an approach can support an understanding of capitalism and its dynamics that is "neither naturalized nor conflated with modernity." Analytical tools such as regimes of engagement, orders of worth, modes of valuation, and evaluative repertoires surface as especially useful tools in this respect. For it is through this attentiveness to the variety of human capacities to judge, evaluate and coordinate -and to the contextual conditions in which these capacities emerge and proliferate -that we become better equipped in unravelling the intricate nexus between modernity and capitalism.

Rethinking the relationship between these two hegemonic social configurations is in fact one of the main challenges that critique, and especially environmental critique, now faces. The approach I have offered in this article is but a small step towards addressing this much larger task.

  /CNRS/EHESS/PSL 190-198 Avenue de France 75013 Paris (France) email: laura.centemeri@ehess.fr

This research was conducted from 2010-2012 as part of the larger research program "Choice beyond incommensurability" I coordinated with José Maria Castro Caldas.

Official data from ENAC: http://www.enac.gov.it/repository/ContentManagement/information/N1171036406/Dati_di_traffico_2015_1607 11.pdf . Accessed the 02/03/2017.

This process of technical alphabetization has been observed in other cases of conflicts against big infrastructures: see in particular[START_REF] Maggiolini | Perícia e transformação dos conflitos ambientais nas grandes obras. O caso da nova linha ferroviária Turim-Lyon[END_REF],[START_REF] Caruso | Il territorio della politica. La nuova partecipazione di massa nei movimenti No Tav e No Dal Molin[END_REF] and Pellizzoni (2011).

On the concept of "affective loyalties" and, more in general, on the role of emotions in mobilization processes see[START_REF] Jaspers | Emotions and Social Movements: Twenty Years of Theory and Research[END_REF]. It is possible to connect modes of valuation to emotions, in the sense that emotions reveal underlying modes of valuation at work in the course of action. According to Nussbaum (as quoted in Jaspers 2011: 289), "emotions always involve thought of an object combined with thought of the object's salience or importance; in that sense, they always involve appraisal or evaluation". In particular, public modes of valuation are connected with the emergence of "moral emotions" where emplaced modes of valuation are instead connected with "affective commitments".

Andrew Hoffman has provided me with valuable insights and a most needed language revision. Research funding was granted by the Portuguese FCT (FCOMP-01-0124-FEDER-009234) and the French ANR (ANR-14-CE03-0005-01).