Patrick DONABÉDIAN

The LA3M Armenian-French archaeological mission of Yereruyk.

Main results of the 2009-2016 campaigns.

Introduction. The LA3M Armenian-French archaeological mission of Yereruyk

placed before the end of the 6 th century, a moment from which begins a new page in the history of Armenian architecture, that of the reign of the dome on cruciform or radiant compositions, with a very specific decorative language, totally absent from Yereruyk. These studies have also revealed that the basilica had close relations with the early Christian monuments of Syria. This relationship is particularly sensitive in the planimetric and volumetric structure of the church, especially in the presence of the two prominent angular chambers that flank the western façade, and to a lesser extent, in the presence of the two laterally elongated sacristies (or pastophoria) of the eastern angles (fig. 4). The affinity with Syria is also notable in the sculpted decor of the basilica, especially the horizontal strips along the south and east façades, and the moldings that border the windows on all their height before folding into small horizontal wings (fig. 2,5). Lastly, this kinship is patent in the field of epigraphy: the Greek inscription carved on the eastern extremity of the southern façade (fig. 6) is very close, both by its content and the form of its frame, to the one carved on the same part of Deir Sem'an church, a Syrian monument of the end of the 5 th century (Jalabert, Mouterde, 1939, p. 232, n° 414).

Two archaeological surveys were carried out under parts of the floor of the basilica where the absence of paving allowed it. One of these investigations concerned the floor of the basilica's main nave, in the southern half of the apsidal zone, and in its south-east part. The "window" thus opened into the basilica's underground allowed important observations. First, no trace of a previous construction, prior to the present basilica, could be found. With several other clues, this observation helps to invalidate a widespread opinion (logical and quite understandable) according to which any early Christian Armenian church is necessarily built on the ruins of a pagan temple. Second, the foundations of the apse's walls and of the southeast angle of the basilica's nave were brought to light and studied. Under the walls, and only there, we could see three courses of stones, laid on the rock, without mortar; the stones of the lowest course were totally rough, those of the highest rather well squared (fig. 7). This confirmed the tradition of a rather "light" system of foundations, as observed in some other monuments of early Christian and medieval Armenian architecture (Donabédian, 2012, p. 173). This survey also revealed that, since the walls of the building, through their "light" foundations, are resting directly on the bedrock, there is no platform, no real crepidoma under the construction. This is important for our apprehension of the five or six steps that surround and seem to precede the basilica (fig. 2,5). It allows us to understand that the impression of a building resting on a crepidoma which this device creates is a false one: it is in fact an imitation of crepidoma.

Another archaeological investigation was carried out under the floor of the southwestern angular chamber of the basilica (fig. 8). Here again, it revealed that there was no pre-Christian layer, and no underground structure, as it was supposed. Such an assumption had been suggested by the presence of a baptismal basin under the floor of the south-western chamber in the Syrian church of Deir Solaib, a monument which can be dated to the 2 nd half of the 5 th century and is typologically close to Yereryuk basilica. This finding was coherent with the tradition according to which Armenians do not practice baptism in a specific construction or in an annex of the church, but in a baptismal niche inside the sanctuary. Largely attested in the Middle Ages, this tradition probably dates back, in Armenia, to the first Christian centuries. On the other hand, the dig under the floor of the south-western chamber revealed an episode hitherto unknown in the history of the basilica: it showed that a fire damaged the original paving, imposing the installation of a second, rougher floor. Thanks to the radiocarbon analysis of fragments of charcoal found there, this fire could be dated between the 8 th and 10 th century.

Concerning again the basilica, an attempt of hypothetical reconstitution of its elevation has been made (fig. 4a). It shows a two-storeyed covering, with a saddleback roof on the main nave, and two pent roofs on the lateral naves, simultaneously covering also the galleries. The choice of such a solution is justified by the fact that the roofs descending from the lateral naves had to pass above the high apses-niches situated at the eastern end of the north and south galleries (fig. 2,9). As for the engaged pillars (or pilasters) inserted in the lateral façades of the basilica, they may leave the impression of having supported a roof, but in reality, they played no role in the covering of the galleries, and the imposts placed on them, deprived of any trace of mortar on their upper surface, have never worn anything. These engaged pillars, as in other monuments of this period, served rather as elements of decoration and perhaps, to a lesser extent, of reinforcement.

Our attempt of reconstitution also shows the protruding and high chambers on the corners, already mentioned above. But what can seem particularly unusual is the north-south incline of the roofs on the eastern pastophoria. This curious incline of the two angular saddleback roofs, lower towards the exterior, higher towards the nave, is obviously imposed by the incline of the beautiful vault, partly preserved on the second level of the north-east pastophorion (fig. 10). As for the lateral galleries, a careful measuring of the preserved elements, especially the first springer of the eastern arch, from both, southeastern and northeastern sides, has allowed to hypothetically reconstruct the external colonnades (fig. 4a), with six columns for the south gallery, and probably six or seven for the north one (fig. 11) (thus much more than on Tokarskiĭ's reconstruction sketch: Tokarskiĭ 1961, p. 78, fig. 22). A variation of our reconstitution proposes a conjectural image of the western façade after its modification (fig. 12), which occurred perhaps soon after the main building campaign, probably as a consequence of a subsidence of the rock platform under the west side of the building (this subsidence is evidenced by the irregularities of the ashlar courses of the western façade). Then a new portico was added, leaned against the façade (fig. 13), much lower than the original one, and this time it was vaulted; it seemed to us possible to imagine that, above this vaulted gallery, a kind of "balcony" has been laid out, as could be seen on many (almost) contemporary Syrian basilicas.

The memorial zone

Since the first campaign, the zone lying to the south and partly to the east of the basilica attracted our attention because of the presence of fragments of sarcophagi (fig. 14), and because of the unusual high number of remains of stepped pedestals (fig. 15) which once wore stelas or columns topped by a cross. On other sites of the same period the number of such monuments, which are relatively frequent in early Christian Armenia and Georgia, does not exceed one or two, except in Aghtsk, Gogaran and Kassagh, where the remains of three or four pedestals and stelas of this type can be seen. In Yereruyk from six to eight of them stood on the south side of the basilica (fig. 4a).

Such an unusually large number of vertical monuments strongly signaled the south façade of the basilica, richly animated by various decorative devices and where two doors opened (fig. 5). It may be supposed that such an effect was linked to a very particular function attached to the sanctuary. It must be remembered that the basilica of Yereruyk, one of the very few in Armenia to have a double dedication, was consecrated to two of Armenia's most popular saints: St. John the Baptist, named the Precursor in an inscription inside the church, and Saint Stephen, named the Protomartyr in the same text mentioning a restoration of the church, but unfortunately not dated. This double mention in an inscription engraved near the apse of the church suggests that the relics of these saints could very well be in the sanctuary, which would explain its strong attractiveness.

Regarding the function of the lower part of these vertical monuments, a testimony of the historian of architecture and archaeologist Alexander Sahinyan, related to the study he had conducted at the basilica of Kassagh in the late 1940s, seemed to indicate that, in addition to wearing stelas or columns, their pedestals could contain burials (Sahinyan 1955, p. 55). Made possible by disturbances suffered by these pedestals, excavations were undertaken in two of them, in order to clarify their function. One of them had already been "visited", but the second one turned out to be uncorrupted (fig. 15). Our digging revealed, at least based on the investigation of one pedestal, that these small stepped platforms served only as podiums for the stelas or columns standing on them (fig. 16). Being filled with compacted earth, they did not contain any burials. As for the rest of what obviously corresponded to a memorial zone, excavations to the south and the south-east of the basilica have shown the presence of a cemetery.

The vertical monuments were erected obviously after the construction of the church, i.e. after the 6 th century, and played an important role in the spatial organization of the memorial-funerary zone, because, as excavations showed it, from the 8 th century onwards, many tombs gathered around them and especially before their west side. This allowed us to date approximately to the 7 th century the pedestals, together with some elements from the vertical memorials once standing on them, presently laid on the rock platform, a short distance north of the basilica.

The cemetery

The aforementioned factors led us to focus on the cemetery, in the area southeast of the basilica, where a certain layer of earth remains, while almost everywhere else the rock touches. As a result of our investigations, seventy-two tombs have been brought to light. Among them twenty-seven samples of human bones could be submitted to radiocarbon analysis and thus dated. They attest that the cemetery functioned since the late Antique period until almost our days.

During this long existence, a first phase could be identified, with five tombs, dated from the 3 rd -6 th centuries. Among various useful data, it testifies to a human activity on the site probably before the construction of the present basilica. The second sequence, the 6 th -8 th centuries, is less represented, at least among the tombs we studied, since it concerns only two of them. On the contrary, the 8 th -11 th centuries, with twelve tombs, correspond to an intense phase of activity. The last active phase covers the 11 th -12 th centuries when four individuals were buried. Then begin low intensity episodes, between the end of the 13 th century and the beginning of the 20 th century. During this last period, occasional burials were practiced, probably due to a rarefaction, then a disappearance of the population, or a gradual abandonment of the cemetery or of the locality.

Throughout the existence of the cemetery, the funerary practices remained mainly the same, with corpses laid on their back, the feet to the east and the head to the west, the arms generally folded on the chest (fig. 17). However, two changes may be noted, with a break between the 10 th and 11 th centuries. The first one concerns the containers: until the 10 th century small stone plates, placed vertically, formed a box, first, at the very beginning of the cemetery's history, rectangular, then trapezoidal (more narrow to the east); whereas from the 11 th century appears a more modest practice of burying the corpses directly in a grave dug in the earth (fig. 18). In both cases, the tombs are covered with portions of horizontal stone plates.

The second change concerns the "recruiting": during the first period, until the 10 th century, it corresponded to a normal parish population, with women, men and children; whereas in the second, from the 11 th century, an absolute predominance of small babies is observed (fig. 19). Concerning the reason for such a change, one of the hypotheses is that a liturgical or dogmatic modification, or a change in the church dedication made it possible to bury near the sanctuary small children who died before receiving the baptism. Indeed, as the inscription engraved inside the basilica seems to suggest, such a change -probably the restoration of the initial dedication to Saint John the Baptist and Saint Steven -could have resulted in installing relics of these two saints in the church of Yereruyk. Presumably, the presence of such relics could constitute a kind of derogatory permission for the burial of very small unbaptized children.

In the part of the cemetery which lies south of the basilica's chevet, the earliest phase is represented by one sole tomb dated between the 3 rd and 5 th centuries, while the actual start of the funerary activity seems to correspond to the 8 th -10 th century. This phase of development is probably linked with the attractiveness of both the basilica and the memorials. Three large pedestals, almost in line with the chevet of the church, have served probably as a reference pole. Immediately in front of their western face, a funerary area, perhaps dynastic, has been installed, where six tombs were arranged in a kind of rectangular enclosure made up of reused blocks (fig. 20). This is one of the earliest manifestations of a later widespread principle in the medieval cemeteries of Armenia, where the khachkars (stone stelas bearing the sculpted image of the cross) are erected to the east of the tombs.

As part of the archaeological examination of the cemetery, the exhumed skeletons have been the subject of a detailed anthropological study. This revealed among others, on two skulls dated between the 3 rd and 5 th century, a curious practice: an intentional deformation by a treatment with bands tightening the cranial box, imposed on the subjects since childhood (fig. 21). This practice was known in antique Armenia and Iran, but until our investigations in Yereruyk, it was not attested in the early Christian period.

We know that furniture, at least in medieval Armenia, is rare in Christian tombs. In Yereruyk, however, in one of the graves, we found a bronze belt buckle (fig. 22). Thanks to the bone under which it was placed, it could be dated to the 7 th -8 th century. It should be noted that buckles of this type, discovered for example in Dvin, have been hypothesized for a later dating (between 9 th and 13 th centuries). Thanks to the Yereruyk finding, we know now that older dates can be attributed to such objects.

The ruins of an incomplete fence wall around the basilica

The first courses of a wall erected to the north and the east of the ecclesiastical zone belonged to a kind of "false rampart" (fig. 23,24). Another wall stood to the south of the cemetery and separated it from the inhabited area, lying more to the south. Irregular and obviously strongly altered in the course of the centuries, the southern wall, against all expectations, proved to be one of the oldest elements of this zone: thanks to excavated tombs and stratigraphy, it can be dated, at least for its oldest part, to the 3 rd -5 th centuries. A door, the threshold of which was discovered in front of the fifth pedestal south of the basilica, made it possible to pass from the memorial zone to the residential area further to the south (fig. 25).

The northern and eastern walls are of another quality, much more regular, especially the eastern, long wall, whose southern extremity seems to have had a link with the upper part of the "dam". This "false rampart" is punctuated by a series of external buttresses and, for the eastern wall, by two "exedras" opening to the west and by a "door" situated at its southern extremity. The investigations tend to show that the eastern wall and its protruding structures resulted from a coherent architectural campaign. The absence of any trace of a fourth wall, west of the basilica, and the relative thinness of the stonework confirm that the ensemble did not form a complete, real rampart. These walls were probably intended not really to protect the ensemble, but to delimitate the sacred area, and especially to emphasize, from outside, from the east, the importance of the basilical group (fig. 26).

Among the two "exedras" of the eastern wall, the northern one, opposite to the southeast corner of the basilica, had a deep pit under its floor, unfortunately, already "visited" (fig. 27). As for the second exedra, further south, with the partly paved floor of its rounded part, it evoked an apse-niche. These two features might have added to the "false rampart" a religious-funerary function. The technical characteristics of these walls, and some elements of decoration of their buttresses (fig. 28) create a certain kinship between them and the basilica, but in the same time, their orientation, slightly different from that of the basilica, in the absence of any topographical or physical justification, suggests that it may be prior to it. This may be an additional indication that, although there is no trace of any structure under the ground of the church, the site was already occupied before the construction of the basilica.

6. The buildings in the valley 6.1. The vaulted building northeast of the basilica: a mausoleum?

The vaulted building, half buried in the small valley to the northeast of the basilica, and partly preserved (fig. 29), had first been interpreted as a cistern. The poor state of conservation of its upper part, and especially of its vault and roof, did not allow excavations, because they could endanger the stability of the whole structure. For that reason, a digging was undertaken outside, at a short distance from its eastern wall, in the hope to find elements allowing to better apprehend, if not its dating, at least its function. It revealed the presence of an accumulation of large blocks in the bottom of the valley, probably aimed at protecting the construction from the water of the seasonal torrent (fig. 30). This, together with the absence of any trace of waterproof plastering inside the building, seemed to contradict the cistern hypothesis, and on the contrary, to strengthen the idea of a mausoleum (both functions were first envisaged by Ter-Martirossov 1987 and2001). Indeed, the rectangular, very carefully vaulted building is oriented, but has no apse at the east, and is almost deprived of primary openings (fig. 31), thus reminding some medieval Armenian mausoleums, for example at Ani cathedral (Totoyan-Baladian, 2008-2009;Karapetian, 2011, pp. 194-195), Sanahin (Khalpakhchjan, 1973, pp. 56-57), Dzagavanq/Getargel, Urtsadzor/Zindjirli (Abgaryan, Tumanyan, 2017, pp. 35, 37), Noravank (Cuneo, 1988, n o 21, pp. 126-127, n° 34, p. 142, and n o 201, pp. 391, 393).

A few architectural clues provide some approximative elements for dating. The technical and metrological characteristics of some parts of the interior wall covering seem to reflect a chronological proximity to the basilica. On the other hand, the sharpness of the saddleback roof and the vertical arrangement of the external cladding blocks on the upper part of south and north façades (fig. 32), added to the affinities with the mausoleums, argue in favor of a dating in the Middle Ages (between 10 th and 14 th century). From these arguments emerges the hypothesis of two stages in the architectural history of the building, one early Christian, and the other, medieval.

6.2. The ensemble of parallel walls to the southeast: a dam or a viaduct?

As for the group of three or four parallel walls crossing the valley, further to the southeast of the basilica (fig. 33), the function of a dam was attested in the 19 th century, according to a testimony collected by N. Marr in the early 20 th century (Marr 1968, p. 9). But the presence of rows of steps and buttresses on the northern (looking upstream) face of the walls (fig. 34) led us to the supposition that the function of this construction could have been different, at least at certain periods, including a possible link with the eastern rampart of the ecclesiastical ensemble. It might have had the function of a viaduct leading to the rampart from hypothetical remains of a road, seemingly visible to the east of the site, on the opposite side of the valley, on the plateau.

Our archaeological and geo-archaeological investigations conducted on different parts of this ensemble of walls led us to the supposition that the construction started probably at the late antique period from the south, probably with the intention of installing a dam of water retention. Indeed, an excavation carried out at the foot of the north side of the first south wall has revealed antique shards. The function of water retention dam seems to agree with the testimonies provided by the epigraphy. These testify that in the Middle Ages the village of Yereruyk was appreciated for the fertility of its land. It is likely that the irrigation made possible by the dam played an important role in the development of this activity, probably stimulated by the proximity of Ani, a densely populated city which became in 961 capital of the country.

Then, the addition of two parallel walls to the north and the backfilling of the intermediate spaces have given rise to the hypothesis of a prestigious viaduct leading to the basilica, combined to the dam function. It should be noted that these two walls successively added to the north (upstream), by their neat and animated north face, seemed to have also the function of enhancing the perspective directed towards the basilica. This feature is further reinforced by the angle that the third wall draws near the small stream, turning clearly to the north-west, towards the southern end of the "oriental" enclosure.

The dating of the set of walls is uncertain. The north face of the intermediate wall, uncovered by the mission, seems to give an indication on this subject. Its high-quality cladding, its pilasters and the arrangement of the ashlar courses (fig. 35) reflect a design and a technique close to those of the basilica. One can, as a simple hypothesis, propose an antique or late antique origin for the first south wall, then attribute to the early Christian period the intermediate wall and roughly locate in the Middle Ages the second enlargement with the third wall.

Investigations on other parts and elements of the site

Vestiges of village

To the west and south of the basilica are the remnants of seemingly rustic and late dwellings (fig. 24, 36). Chimney houses can be identified in the south, and stables or sheepfolds in the west. Extensive clearance work undertaken in this vast area in 1987-88 has unfortunately not been documented and the remains have since been abandoned. Nevertheless, the available archaeological and epigraphic data leave no doubt about the existence here of an ancient settlement. It probably dates to late antiquity and corresponds to at least part of the large medieval village of Yereruyk attested in the epigraphic sources.

Two underground rooms

Under the rock platform north of the basilica are two underground rooms dug in the rock, or more probably slightly regularized caverns, partly stretched from west to east and roughly parallel (fig. 37, 38). Because of their approximate orientation, they have been identified to chapels, supposedly early Christian (Ter Martirosov 1987, 2001). But nothing really confirms this assertion.

Fragments of sculpted stones

More than two hundred remains of sculpted or molded stones are present on the site. Most of them have been gathered on the rock platform north of the basilica. Many of these stones belong to major architectural forms, mainly to the basilica itself, for example fragments of columns or capitals from its galleries (fig. 39). The others come from smaller forms of the memorial sphere, such as stelas. One of them is a fragment of a stela, whose four sides are covered with very eroded images of saints and angels (fig. 40). There are also dozens of tombstones which belong to a type prevalent in medieval Armenia, with the characteristic shape of a saddleback on a parallelepipedal base. Today almost all have been moved north of the basilica. But originally, these stones served as surface markers for burials dug in the ground, a few dozen centimeters lower. The size of each stone corresponded roughly to that of the tomb and therefore to the height or age of the deceased (fig. 41). The flatter ones, whose shape approaches that of the sarcophagus lids, seem to be the oldest (fig. 42). On the contrary, those closer to the Middle Ages have a much higher volume and a steeper inclination of the saddleback.

Preservation and valorization

The preservation of the rich ensemble of ruined monuments and various remnants of Yereryuk, as well as the enhancing of their value, is a very important issue, due to the considerable signification that the basilica, the memorial zone on its south side, the other ruins of buildings and the numerous elements of their decoration present for the history of art and architecture. Moreover, considering the precarious state of the neighboring village, the prospect of a touristic exploitation of the site might improve the life standard of local population.

For this reason, in cooperation with the Armenian authorities, our mission has joined the European organization Europa Nostra and the architect Gaianè Casnati, and together with them, tried to promote a preservation and valorization plan including the creation of a protected patrimonial zone. This zone would comprise the complex of Yereruyk and the village of Anipemza, with its very valuable buildings of the 1920s-30s. The inscription of the site on UNESCO's World Heritage List should facilitate the achievement of this objective.

Conclusion

Thanks to the investigations carried out by the French-Armenian mission of LA3M in Yereruyk from 2009 to 2016, important results, briefly described above, have been recorded. Some of the questions exposed in the introduction could be elucidated. Our knowledge of the Yereruyk basilica has been improved, as well as that of various components of the site. Excavations conducted southeast of the basilica have allowed, for the first time in Armenian archeology, to systematically study a medieval cemetery and establish a typo-chronological analysis of the burials, which highlighted the need to develop the "archaeology of Christian death" in Armenia.

The reasons for the presence of such a complex and the conditions of its existence over the centuries, especially when the large city of Ani was flourishing in its vicinity, have been more thoroughly apprehended thanks to a better appreciation of the dedication of the basilica to two very popular saints, of the tightness of its links with Syria, and of the use of the water retention dam.

The detailed master plan, prepared for the first time by the mission, makes it possible to measure the extent of the Yereruyk complex. This observation naturally questions, especially concerning its nature, i.e. the function(s) of this large group of vestiges, taken as a whole. The architectural features of its various components do not favor a monastic hypothesis, and in this sense Yereruyk does not resemble the great monastic complexes of early Christian Syria. It should be recalled in this regard that there are no architectural and archaeological evidences that monastic structures related to cenobitic communities had existed in Armenia before the end of the Arab occupation. On the other hand, the attractiveness of the Yereruyk ensemble, which one might assume to be quite strong, was probably related to the presence of relics. One can thus easily imagine the large church of Yereruyk as a popular place of pilgrimage, frequented of course by the local population, but perhaps also by Syrians.

It is understandable that, given the duration and the limited means of the mission, the many puzzles posed by Yereruyk site are far from having been fully solved. Hopefully, the questions that remain to be elucidated will provide an abundant material for future missions that will focus on the study of this remarkable site. 16. Schema of a monument supporting a cross-topped column or stele, with a section of its pedestal. Drawing by S. Mnatsakanyan (after Mnatsakanyan, 1982). Fig. 21. Cemetery. Burial n° 44A (between 256 and 407). Deformed skulls of an adult and an 8-9-year-old child. Photos P. Bailet (LA3M). Fig. 22. Cemetery. Bronze belt buckle from burial n° 46 (between 606 and 766). Photo D. Martinez (LA3M).

Fig. 1 .

 1 Fig. 1. Yereruyk. General plan of the site. Fig. 2. Yereruyk, basilica. General view from the southwest. Fig. 3. Yereruyk, basilica. Plan of its current state. Plans of three-nave basilicas of early Christian Armenia, including Yereruyk. Fig. 4. Three-dimensional restitution of Yereruyk basilica. Designed by P. Donabédian, executed by D. Ollivier (LA3M). Elevation restitutions of four early Christian Syrian basilicas (drawings by M. de Vogüé and J. Mattern, after Mattern, 1944). Fig. 5. Yereruyk, basilica. South façade. Fig. 6. Basilica. East end of the south façade. Greek inscription (Psalm 92). Fig. 7. Basilica. Right part of the apse (= southeast extremity of main nave). Foundations. Photo D. Martinez (LA3M). Fig. 8. Basilica. Southwest angular chamber. Excavation under the floor. Fig. 9. Basilica. General view from the northwest. Fig. 10. Basilica. Northeast sacristy. Two superimposed vaults. Fig. 11. Basilica. North and south façades. Attempt of restitution of the gallery colonnades. Layout and CAD by G. Marchand, P. Donabédian and D. Ollivier (LA3M). Fig. 12. Basilica. Hypothetical restitution of the west gallery after its modification. Hypothesis of a "balcony" over the vault. Fig. 13. Basilica. West façade. Remains of the second, lowered gallery, leaned against the façade. Fig. 14. Memorial zone southeast of the basilica. Vestiges of sarcophagi. Fig. 15. Memorial zone south of the basilica's chevet, with a row of three pedestals. Fig. 16. Schema of a monument supporting a cross-topped column or stele, with a section of its pedestal. Drawing by S. Mnatsakanyan (after Mnatsakanyan, 1982). Fig. 17. Cemetery southeast of the basilica. Tombs n o 28 and 61 (late 8 th -10 th c.). Photo D. Martinez (LA3M). Fig. 18. Cemetery. Tomb n° 49 (between 1514 and 1798). Fig. 19. Cemetery. Tombs of very small children, n° 24 (undated), 18 (between 1018 and 1151), and 9 (between 1284 and 1396). Photos D. Martinez (LA3M). Fig. 20. Cemetery. Zone south of the basilica's chevet. Attempt of burials phasing by D. Martinez (LA3M).Fig. 21. Cemetery. Burial n° 44A (between 256 and 407). Deformed skulls of an adult and an 8-9-year-old child. Photos P. Bailet (LA3M). Fig.22. Cemetery. Bronze belt buckle from burial n° 46 (between 606 and 766). Photo D. Martinez (LA3M). Fig. 23. Eastern "enclosure". View from the south-east. Fig. 24. General view of the central part of the site. Fig. 25. Wall south of the basilica. Threshold of a door opening on the inhabited area, further south. Photo L. Harutyunyan (LA3M). Fig. 26. Eastern "enclosure". Schematic restitution. Designed by A. Hartmann-Virnich, executed by D. Ollivier (LA3M). Fig. 27. Eastern "enclosure". North "exedra". Fig. 28. Eastern "enclosure". Base of a buttress. Fig. 29. Vaulted building northeast of the basilica. General view from the northeast. Fig. 30. Vaulted building. Excavation a few meters to the east of the building. Fig. 31. Vaulted building. Internal view to the east. Fig. 32. Vaulted building. East and west façades (the openings are not original). Fig. 33. "Dam". General view from the southeast, towards the basilica. Fig. 34. "Dam". North side of the northernmost wall. View from the northwest.

Fig. 17 .

 17 Fig. 1. Yereruyk. General plan of the site. Fig. 2. Yereruyk, basilica. General view from the southwest. Fig. 3. Yereruyk, basilica. Plan of its current state. Plans of three-nave basilicas of early Christian Armenia, including Yereruyk. Fig. 4. Three-dimensional restitution of Yereruyk basilica. Designed by P. Donabédian, executed by D. Ollivier (LA3M). Elevation restitutions of four early Christian Syrian basilicas (drawings by M. de Vogüé and J. Mattern, after Mattern, 1944). Fig. 5. Yereruyk, basilica. South façade. Fig. 6. Basilica. East end of the south façade. Greek inscription (Psalm 92). Fig. 7. Basilica. Right part of the apse (= southeast extremity of main nave). Foundations. Photo D. Martinez (LA3M). Fig. 8. Basilica. Southwest angular chamber. Excavation under the floor. Fig. 9. Basilica. General view from the northwest. Fig. 10. Basilica. Northeast sacristy. Two superimposed vaults. Fig. 11. Basilica. North and south façades. Attempt of restitution of the gallery colonnades. Layout and CAD by G. Marchand, P. Donabédian and D. Ollivier (LA3M). Fig. 12. Basilica. Hypothetical restitution of the west gallery after its modification. Hypothesis of a "balcony" over the vault. Fig. 13. Basilica. West façade. Remains of the second, lowered gallery, leaned against the façade. Fig. 14. Memorial zone southeast of the basilica. Vestiges of sarcophagi. Fig. 15. Memorial zone south of the basilica's chevet, with a row of three pedestals. Fig. 16. Schema of a monument supporting a cross-topped column or stele, with a section of its pedestal. Drawing by S. Mnatsakanyan (after Mnatsakanyan, 1982). Fig. 17. Cemetery southeast of the basilica. Tombs n o 28 and 61 (late 8 th -10 th c.). Photo D. Martinez (LA3M). Fig. 18. Cemetery. Tomb n° 49 (between 1514 and 1798). Fig. 19. Cemetery. Tombs of very small children, n° 24 (undated), 18 (between 1018 and 1151), and 9 (between 1284 and 1396). Photos D. Martinez (LA3M). Fig. 20. Cemetery. Zone south of the basilica's chevet. Attempt of burials phasing by D. Martinez (LA3M).Fig. 21. Cemetery. Burial n° 44A (between 256 and 407). Deformed skulls of an adult and an 8-9-year-old child. Photos P. Bailet (LA3M). Fig.22. Cemetery. Bronze belt buckle from burial n° 46 (between 606 and 766). Photo D. Martinez (LA3M). Fig. 23. Eastern "enclosure". View from the south-east. Fig. 24. General view of the central part of the site. Fig. 25. Wall south of the basilica. Threshold of a door opening on the inhabited area, further south. Photo L. Harutyunyan (LA3M). Fig. 26. Eastern "enclosure". Schematic restitution. Designed by A. Hartmann-Virnich, executed by D. Ollivier (LA3M). Fig. 27. Eastern "enclosure". North "exedra". Fig. 28. Eastern "enclosure". Base of a buttress. Fig. 29. Vaulted building northeast of the basilica. General view from the northeast. Fig. 30. Vaulted building. Excavation a few meters to the east of the building. Fig. 31. Vaulted building. Internal view to the east. Fig. 32. Vaulted building. East and west façades (the openings are not original). Fig. 33. "Dam". General view from the southeast, towards the basilica. Fig. 34. "Dam". North side of the northernmost wall. View from the northwest.

Fig. 23 .

 23 Fig. 1. Yereruyk. General plan of the site. Fig. 2. Yereruyk, basilica. General view from the southwest. Fig. 3. Yereruyk, basilica. Plan of its current state. Plans of three-nave basilicas of early Christian Armenia, including Yereruyk. Fig. 4. Three-dimensional restitution of Yereruyk basilica. Designed by P. Donabédian, executed by D. Ollivier (LA3M). Elevation restitutions of four early Christian Syrian basilicas (drawings by M. de Vogüé and J. Mattern, after Mattern, 1944). Fig. 5. Yereruyk, basilica. South façade. Fig. 6. Basilica. East end of the south façade. Greek inscription (Psalm 92). Fig. 7. Basilica. Right part of the apse (= southeast extremity of main nave). Foundations. Photo D. Martinez (LA3M). Fig. 8. Basilica. Southwest angular chamber. Excavation under the floor. Fig. 9. Basilica. General view from the northwest. Fig. 10. Basilica. Northeast sacristy. Two superimposed vaults. Fig. 11. Basilica. North and south façades. Attempt of restitution of the gallery colonnades. Layout and CAD by G. Marchand, P. Donabédian and D. Ollivier (LA3M). Fig. 12. Basilica. Hypothetical restitution of the west gallery after its modification. Hypothesis of a "balcony" over the vault. Fig. 13. Basilica. West façade. Remains of the second, lowered gallery, leaned against the façade. Fig. 14. Memorial zone southeast of the basilica. Vestiges of sarcophagi. Fig. 15. Memorial zone south of the basilica's chevet, with a row of three pedestals. Fig. 16. Schema of a monument supporting a cross-topped column or stele, with a section of its pedestal. Drawing by S. Mnatsakanyan (after Mnatsakanyan, 1982). Fig. 17. Cemetery southeast of the basilica. Tombs n o 28 and 61 (late 8 th -10 th c.). Photo D. Martinez (LA3M). Fig. 18. Cemetery. Tomb n° 49 (between 1514 and 1798). Fig. 19. Cemetery. Tombs of very small children, n° 24 (undated), 18 (between 1018 and 1151), and 9 (between 1284 and 1396). Photos D. Martinez (LA3M). Fig. 20. Cemetery. Zone south of the basilica's chevet. Attempt of burials phasing by D. Martinez (LA3M).Fig. 21. Cemetery. Burial n° 44A (between 256 and 407). Deformed skulls of an adult and an 8-9-year-old child. Photos P. Bailet (LA3M). Fig.22. Cemetery. Bronze belt buckle from burial n° 46 (between 606 and 766). Photo D. Martinez (LA3M). Fig. 23. Eastern "enclosure". View from the south-east. Fig. 24. General view of the central part of the site. Fig. 25. Wall south of the basilica. Threshold of a door opening on the inhabited area, further south. Photo L. Harutyunyan (LA3M). Fig. 26. Eastern "enclosure". Schematic restitution. Designed by A. Hartmann-Virnich, executed by D. Ollivier (LA3M). Fig. 27. Eastern "enclosure". North "exedra". Fig. 28. Eastern "enclosure". Base of a buttress. Fig. 29. Vaulted building northeast of the basilica. General view from the northeast. Fig. 30. Vaulted building. Excavation a few meters to the east of the building. Fig. 31. Vaulted building. Internal view to the east. Fig. 32. Vaulted building. East and west façades (the openings are not original). Fig. 33. "Dam". General view from the southeast, towards the basilica. Fig. 34. "Dam". North side of the northernmost wall. View from the northwest.

Fig. 27 .

 27 Fig. 1. Yereruyk. General plan of the site. Fig. 2. Yereruyk, basilica. General view from the southwest. Fig. 3. Yereruyk, basilica. Plan of its current state. Plans of three-nave basilicas of early Christian Armenia, including Yereruyk. Fig. 4. Three-dimensional restitution of Yereruyk basilica. Designed by P. Donabédian, executed by D. Ollivier (LA3M). Elevation restitutions of four early Christian Syrian basilicas (drawings by M. de Vogüé and J. Mattern, after Mattern, 1944). Fig. 5. Yereruyk, basilica. South façade. Fig. 6. Basilica. East end of the south façade. Greek inscription (Psalm 92). Fig. 7. Basilica. Right part of the apse (= southeast extremity of main nave). Foundations. Photo D. Martinez (LA3M). Fig. 8. Basilica. Southwest angular chamber. Excavation under the floor. Fig. 9. Basilica. General view from the northwest. Fig. 10. Basilica. Northeast sacristy. Two superimposed vaults. Fig. 11. Basilica. North and south façades. Attempt of restitution of the gallery colonnades. Layout and CAD by G. Marchand, P. Donabédian and D. Ollivier (LA3M). Fig. 12. Basilica. Hypothetical restitution of the west gallery after its modification. Hypothesis of a "balcony" over the vault. Fig. 13. Basilica. West façade. Remains of the second, lowered gallery, leaned against the façade. Fig. 14. Memorial zone southeast of the basilica. Vestiges of sarcophagi. Fig. 15. Memorial zone south of the basilica's chevet, with a row of three pedestals. Fig. 16. Schema of a monument supporting a cross-topped column or stele, with a section of its pedestal. Drawing by S. Mnatsakanyan (after Mnatsakanyan, 1982). Fig. 17. Cemetery southeast of the basilica. Tombs n o 28 and 61 (late 8 th -10 th c.). Photo D. Martinez (LA3M). Fig. 18. Cemetery. Tomb n° 49 (between 1514 and 1798). Fig. 19. Cemetery. Tombs of very small children, n° 24 (undated), 18 (between 1018 and 1151), and 9 (between 1284 and 1396). Photos D. Martinez (LA3M). Fig. 20. Cemetery. Zone south of the basilica's chevet. Attempt of burials phasing by D. Martinez (LA3M).Fig. 21. Cemetery. Burial n° 44A (between 256 and 407). Deformed skulls of an adult and an 8-9-year-old child. Photos P. Bailet (LA3M). Fig.22. Cemetery. Bronze belt buckle from burial n° 46 (between 606 and 766). Photo D. Martinez (LA3M). Fig. 23. Eastern "enclosure". View from the south-east. Fig. 24. General view of the central part of the site. Fig. 25. Wall south of the basilica. Threshold of a door opening on the inhabited area, further south. Photo L. Harutyunyan (LA3M). Fig. 26. Eastern "enclosure". Schematic restitution. Designed by A. Hartmann-Virnich, executed by D. Ollivier (LA3M). Fig. 27. Eastern "enclosure". North "exedra". Fig. 28. Eastern "enclosure". Base of a buttress. Fig. 29. Vaulted building northeast of the basilica. General view from the northeast. Fig. 30. Vaulted building. Excavation a few meters to the east of the building. Fig. 31. Vaulted building. Internal view to the east. Fig. 32. Vaulted building. East and west façades (the openings are not original). Fig. 33. "Dam". General view from the southeast, towards the basilica. Fig. 34. "Dam". North side of the northernmost wall. View from the northwest.

Fig. 35 .

 35 Fig. 35. "Dam". North side of the middle wall. Fig. 36. Vestiges of dwellings to the south of the basilica. Fig. 37. Two underground rooms north or the basilica. Plan after F. Ter-Martirosov, 1985. Fig. 38. The northern underground room north or the basilica. View towards the east. Fig. 39. Portions of column shafts northeast of the basilica, from its galleries. Fig. 40. Fragment of a four-sided stela (c. 7 th c.) from a vertical cross-topped monument (46 x 42,5 x 127 cm) -a) left side; b) anterior ("main") side; c) right side; d) posterior side. Fig. 41. Relatively flat tombstones, probably archaic. Fig. 42. Medieval tombstones, and three cubic bases of four-sided stelas.

 Mattern, J., 1944.Villes mortes de Haute Syrie. Imprimerie catholique, Beyrouth. Sahinyan, A., 1955. Kasaghi bazilikayi tjartarapetutyun (in Armenian). Gitutyunneri Akademia, Yerevan. Ter-Martirosov, F., 1987. Arkheologicheskie razyskanija pamjatnikov v Ereruĭke (in Russian). In: VI Respublikanskaja nauchnaja konferentsija po problemam kuljtury i iskusstva Armenii. Akademija Nauk, Yerevan, pp. 216-218. Ter-Martirossov, F., 2001. Malo izuchennye pamjatniki Yereruĭka (in Russian). In: Hayots srber yev srbavayrer. Gitutyunneri Akademia, Yerevan, pp. 234-243. Tokarskiĭ, N.M., 1961. Arkhitektura Armenii IV-XIV vv. (in Russian). Akademija Nauk, Yerevan.

Totoyan-Baladian, A., 2008-2009. L'édifice à étoiles de la cathédrale d'Ani. Revue des Études Arméniennes (REArm) 31, pp. 233-243.

ABSTRACT

The LA3M Laboratory of Aix Marseille University (France), in cooperation with the Institute of Archaeology and Ethnography of the Armenian Academy, represented on the ground by the Regional Museum of Shirak, has carried out, from 2009 to 2016, an archaeological survey of the early Christian and medieval site of Yereruyk. The project was aimed at a multidisciplinary approach of the complex, combining armenology, history of art and architecture, building archaeology, classic archaeology, archaeological anthropology, and geo-archaeology.

One of the purposes was to better understand the reasons why such a large ensemble had been established in a space now deprived, at the northwestern tip of the country. The complex includes the vestiges of several buildings, among which an early Christian basilica, a vaulted construction which served perhaps as a mausoleum, the remains of a "false rampart", and of a series of parallel walls corresponding, at a certain period, to a dam, two underground halls, and numerous fragments of sculpted stones. A special attention was paid to the basilica and to the cemetery, where twenty-seven tombs were studied in detail. Another objective was to try to clarify the absolute and relative dating of the main buildings, as well as the function of many of them, which was still unclear. The mission also sought to specify the relationship which must have existed around the year one thousand between the religious complex and the medieval capital Ani, from which it is only some kilometers away. KEYWORDS 1. Yereryuk (Ereruyk). 2. Medieval archaeology. 3. Funerary archaeology. 4. History of architecture. 5. Early Christian and medieval Armenia. 6. Early Christian Syria.

List of illustrations with captions (Unless otherwise stated, the photos are from the author.)


Hervé This Vo Kientza

This H 2009 Les

Culinaires

This Vo

Kientza H 2021 Sauces

Burke R In

An emulsion in the making

International Journal of Molecular and Physical Gastronomy (IJMPG) Picture of the week

The sauce that we call today "mayonnaise" was derived from "rémoulade" (or "rémolade"), which existed already in the 15th century (Tirel, 1419): both sauces are hot or cold oil in water (O/W) emulsions for which the liquid fat is

International Journal of Molecular and Physical Gastronomy

(IJMPG) Picture of the week mayonnaise appeared at the end of the 18th century as a very different product [START_REF] Carême | L'art de la cuisine française au 19e siècle[END_REF]. It was indeed a surprise that an emulsion could be made without mustard, from egg yolk, vinegar, salt, pepper and oil (howewer, today, it is understood that the emulsifying agents from the egg yolks are primarily proteins and phospholipids, i.e. the same than in mustard). The flavour of mayonnaise was recognized to be very different from the one of rémoulade [START_REF] Carême | L'art de la cuisine française au 19e siècle[END_REF]Gilbert,1898). When mayonnaise appeared, it was first called mahonnaise, or magnonaise [START_REF] Carême | L'art de la cuisine française au 19e siècle[END_REF]. At that time, it was made using a mortar and a pestle, or with a wooden spoon with which the walls of the vessel were rubbed for up to 15 minutes, and it was observed that the more the sauce was ground, the lighter its colour was [START_REF] Carême | L'art de la cuisine française au 19e siècle[END_REF][START_REF] Saint-Ange | La bonne cuisine de Madame Saint-Ange[END_REF]. Also it was observed that mayonnaise can fail, i.e., the water and oil phases sometimes separate. This happens in the start of the process, when too much oil is added in the small quantity of aqueous solution (from the yolk and the vinegar), or at the end, when the viscosity of the sauce is high, the oil proportion becoming more than 95 %. However, in the past, the physical structure of mayonnaise was unknown, and many explanations were given for failed emulsions, such as differences in temperature of the yolks and the oil, changes in the direction of whipping, the presence of women with periods in the kitchen, or even a storm outside (This, 2009). However all this was imagination, because the only question, during the making of the sauce, it to divide the oil in droplets that are dispersed in the aqueous solution made of vinegar (about 90 % water) and egg yolk (about 50 % water); surfactants from the egg yolk (proteins and phospholipids) lower the surface energy and prevent droplets coalescence (charged proteins at the surface of droplets create both steric hindrance and electrostatic repulsion). Any technique that can emulsify the oil in water can be used. For example, in order to make the sauce whose microscopic appearance is shown here, a fork was used to whisk it. At the beginning of the emulsification process, the sauce remains fluid (the picture shown here corresponds to the addition of about 50 % oil), but after more oil is added, or when the whisking energy is high (corresponding to smaller oil droplets), the viscosity is much increased. It can be noted that understanding the physical structure of this sauce was not easily obtained, in spite of the availability of microscopes since the 17th century [START_REF] Leeuwenhoek | A Specimen of Some Observations Made by a Microscope, Contrived by A. Leeuwenhoek in Holland, Lately Communicated[END_REF]: for example, a search in Google scholar does not show any scientific article with the keywords mayonnaise+emulsion between 1850 and 1900. Even in the 1980's, the surfactants in mayonnaise were said to be phospholipids, and it was even said in kitchens that the slightest trace of egg white would prevent making the sauce [START_REF] Gencé | Encyclopédie de la vie pratique[END_REF]. However, an emulsion can be obtained by whipping oil in egg whites (in which there are no phospholipids, but only proteins) (This, 2021): this shows how effective proteins are for emulsification, having both large steric hindrance (with 386 residues of amino acid, the fully extended ovalbumin would be about 60 nm long) [START_REF] Stein | Crystal structure of uncleaved ovalbumin at 1.95[END_REF] and electric charges (the isoelectric point is 4.5, i.e. higher than in mayonnaise) preventing coalescence [START_REF] Strixner | Egg proteins[END_REF]. To take the picture shown here, a few mm³ of sauce were taken with a spatula and gently spread on a glass slide, without a cover (in order not to disturb the system). In this image, produced with a Meiji microscope (Techno ML Series 2000, model ML2300, equipped with a JVC camera, TKC1380), two types of objects can be seen: numerous discs without dark edges (oil droplets) and discs with dark edges (air bubbles). The diameter of the biggest structures is ~ 0.1 mm.


Tarik Eljaddi

Lizeth Deisy

Eric Mejia Mendez

Denis Favre

Roizard

Denis Roizard
email: denis.roizard@univ-lorraine.fr

Development of new pervaporation composite membranes for desalination: membrane characterizations and experimental permeation data

Keywords: Hydrophobic composite membranes, contact angles, water permeance, conductivity, desalination

The data contained in this publication refers to a new approach to design composite pervaporation membranes that could be useful in water treatment.

The work is based on the rational prediction of the membrane mass transfer coefficient using the resistance in series model and the corresponding experimental membranes were tested with several aqueous solutions comparatively to a commercially available porous distillation membrane (PVDF).

All the related data, i.e. permeation water fluxes and conductivity of the permeate, were collected for hours, in the range 3 to 7 h. The strategy was to develop pervaporation membranes by coating a porous PVDF support (122µm) with various dense layers (hydrophobic polymers: Teflon™ AF2400, PMP, PTMSP). The objective was to avoid definitely the wetting problem observed in membrane distillation while keeping approximately the permeance than the porous support. The data reported here are related to the surface property of the membranes (contact angles), to the mechanical resistance of the membranes, to the wetting phenomena observed directly and recorded by observing the variation of water flux through the membranes and to the conductivity of the water condensed at the permeate side.

Specifications Table

Subject

Chemical Engineering

Specific subject area desalination, pervaporation, membrane distillation

Type of data Table, Image, Figure

How data were acquired The porous and composites membranes were tested in direct contact configuration cell with an active surface of 40 cm². The centrifuge pumps, temperature, and flux sensors are provided from RS Components, the bench conductivity meter is a Jenway 4520 and the balance is from Sartorius (0.01 g). The data related to mass transfer were recorded using LabVIEW software, the images were recorded in 12 megapixels size with the camera of a smartphone (Samsung 7). The contact angles were measured with the apparatus Dataphysics Instruments GmbH (DI) Germany equipped with a goniometer OCA-PSA Drop 8 using the software SCA20.

Data format

Raw and Analyzed

Parameters for data collection

The porous support and hydrophobic composite membranes were prepared and characterized by several solutions (Distillated water, salt solutions with or without surfactant, i.e. SDS)

Description of data collection

The operating conditions are as follows:

-Both the feed and the permeate solutions were circulated in close loops The water vapor which permeates through the membrane is condensed on the downstream side in the flowing cold liquid. The excess of liquid is directly collected and weighted. In these conditions of steady state, the mass increase is linear versus time

-

Data source location

Université de Lorraine, CNRS, LRGP, F-54000 Nancy, France

Data accessibility

With the article as Excel file

Related research article

Tarik Eljaddi, Deisy Lizeth Mejia Mendez, Eric Favre, Denis Roizard, Development of new pervaporation composite membranes for desalination: theoretical and experimental investigations, submitted [START_REF] Eljaddi | Rational and experimental approaches to develop composite membranes for desalination by pervaporation[END_REF].

Value of the Data

-

The data of the permeation experiments show that significant water fluxes can be obtained with the lab-made pervaporation membranes using operating conditions similar to membrane distillation.

-These data will be a useful reference for the researchers who will try to develop improved PV membranes for desalination. Indeed these data provide valuable information to understand the wetting problem with porous membrane by direct observation and by recording the variation parameters like flux and conductivity.

-Calculation of the mass transfer coefficients was made accordingly to the resistance in series model. The permeation data will be useful to test further models of pervaporation mass transfer.

Data Description

The data describe the direct contact membrane distillation configuration used to carry out the experiment and show the hydrophobicity property of porous PVDF (Figure 1-a, b), the automatic recording of the permeate weight and the steady state reached after 1 h (Figure 2). The Finally, the Table 1 gathers the value of mass transfer and permeability corresponding with the variation of thickness, Table 2 and Table 3 represent respectively the contact angle data and pull-off test data of pristine PVDF and composites membranes.

Experimental design, materials, and methods

Membrane modification

The first step was the preparation of the polymer solution, with the dissolution of the polymer mass in cyclohexane (2wt% PMP, 2wt% PTMSP) or in Fluorinert FC 75TM (1wt% Teflon™ AF2400) to obtain homogenous solutions. The polymer was added as a powder in the solvent and stirred overnight to get clear solutions. All remaining particles were filtered before used. In the second step, the air bubbles of the solutions were eliminated with an ultrasonic bath for 5mn and then the applicator film (Elcometer 4340 Motorized Film Applicator) was used to cast the polymer solutions as wet thin films (about 50 micrometers) on the surface of the PVDF support. After the evaporation of the solvent, composite membranes were obtained and dried carefully for several hours in an oven (50°C) before characterization and utilization.

Permeance determination

The transmembrane water flux of the membranes was measured with a direct contact setup (Figure 1). Flat samples of membranes of 40cm² were used. The centrifuge pumps, temperature, and flux sensors were provided from RS Components. The conductivity of the feed solutions and of the permeate were measured with a bench conductivity meter, brand

Jenway 4520[9] measured with a balance, brand Sartorius, accuracy 0.01 g. During the experiments, both the conductivity and the mass variation were acquired continuously online.

The operating conditions were as follows:

-Both the feed and the permeate solutions circulate in close loops of about 1.5L each.

-Cross flow is ensured on each side of the membrane in a counter current way.

-Pump flow rates: respectively 1L/min on the feed side and 0.8L/min on the permeate sidethe water vapor is condensed on the cold side and is continuously weighted by the balance as the water in excess coming through the membrane.

-The conductivity of water is continuously measured and recorded in microsiemens (µS/cm)the initial conductivity of the 3g/L and 10g/L feed solutions as respectively 6.5 and 18.9 mS/cm at room temperature.

Contact angle measurements

Samples of 2 cm x 2 cm were prepared for each membrane and fixed horizontally in the contact angles DI apparatus. Water drop of 7 µl was deposited on membrane surface using a perpendicular syringe. The picture of the water drop, and membrane were taking using a specific camera, and with a software, the angle contact was calculated. For each sample the measurement was repeated several times using several drops deposited at different places (Table 2) till the mean deviation was below 4°.

Pull-off test measurements

The adhesion between porous support PVDF and dense hydrophobic dense layer of AF2400, PMP and PTSMP was mechanically checked using the device Elcometer 510. The membrane sample was fixed between a metallic support and sample support (diameter of 20 mm) by Locite Snellijmen Glue. After certain time when the glue was dried, the automatic gauge was

8 L

 8 Cross flow is ensured on each side of the membrane -Flow rates are respectively 1 L/min on the feed side and 0./min on the permeate side -Water vapor is condensed on the cold side and is continuously weighted by the balance as the water in excess the conductivity of water is continuously measured and recorded in microsiemens per cm (µS/cm) For each experiment, the feed solution, initially pure water on the feed side, is circulated during about 2 hours to reach steady state conditions linked to the stabilization of temperatures on both side of the membrane. The warm and cold temperatures are recorded at the inputs and outputs of the membrane cell.

Figure 3

 3 shows an example of temperature stability registered at the feed and at the permeate sides. The recorded water fluxes of the pristine PVDF and of the hydrophobic composite membranes are presented in Figure 4 and an example of the water flux of PVDF+AF2400 for more than 8 h are presented in Figure 5. The Figure 6 presents the variation of water permeance through pristine PVDF with different feeds: distilled water, several salt feed solutions with and without surfactant. The increase of the permeate conductivity can be related to the wetting phenomenon. The transparent cell allows to see the wetting steps: it starts on the feed side, at the aqueous solution inlet, by partial wetting, leading after sometimes to total wetting (Figure 7 a-e).

Figure 1

 1 Figure 1-a, b: a) View of the flat cell used for the desalination experiments: total area 40cm 2 , direct contact membrane distillation configuration (DCMD). The downstream side is shown here with a piece of a PVDF membrane in place. The cell was home-made using a transparent glassy material (PMMA) to help the visualization of the tangential flow and of the wetting phenomenon.

Figure 2 :

 2 Figure 2: Automatic recording of the permeate weight: steady state is reached after about 1h. The main governing parameter is the temperature regulation. The stabilized slope is 85.6 g/h for pristine PVDF.

Figure 3 :Figure 4 :

 34 Figure 3: Example of the stability of feed and permeate temperatures versus time. Case of PVDF and Teflon™ AF2400 experiments with pure water.

Figure 5 :

 5 Figure 5: Example of flux stability versus time. Case of PVDF coated with Teflon™ AF 2400, long lasting experiment with pure water.

Figure 6 :

 6 Figure 6: Investigation of the wetting resistance of the membranes versus feeds containing successively NaCl (up to 10g/L) and NaCl with a surfactant (SDS 1g/L). The addition of the surfactant induces first the partial the wetting of the membrane (time≈3h) and then a liquid convective flux through all pores (time≈5.5h).

Figure 7 :

 7 Figure 7: Visualization of the wetting phenomena with a porous PVDF membrane, from the feed inlet to the feed outlet. Feed: NaCl 10g/L + 1g/L SDS à 50°C. On the Fig. 7_b) and Fig. 7_c) the dark strips indicate some partial wetting.

Table 1 :

 1 Permeability of glassy polymers for water (P, Barrer) and related mass transfer coefficient versus thickness of the active layer[START_REF] Mejia Mendez | Membrane distillation (MD) processes for water desalination applications. Can dense self-standing membranes compete with microporous hydrophobic materials?[END_REF][START_REF]Polymethylpentene Film -online catalog source -supplier of research materials in small quantities -Goodfellow[END_REF].

	____
	2 cm	Feed INLET
					Wetting
					100 %
	NO
	wetting	Feed OUT LET
	a) t=0	b ) t ≈3h	c )	d )	e) t≈5.5h
		PVDF	PTMSP	PMP	Teflon AF2400
		Porous	Dense layer	Dense layer	Dense layer
	Permeability (Barrer ±10%)	NA	11 200	1 000	4000
	Thickness (µm)		Mass transfer coefficient (m/s)
		PVDF a	PTMSP b	PMP b	Teflon AF2400 b
	500	2.30E-02	1.94E-05	1.73E-06	6.90E-06
	200	5.64E-02	4.85E-05	4.33E-06	1.73E-05
	2	/	4.85E-03	4.33E-04	1.73E-03
	0.2	/	4.85E-02	4.33E-03	1.73E-02
	a) Calculated from the measured water permeance according to the reference [4]
	b) Calculated from the water permeability data [2,3,5]

Table 2 :

 2 Contact angle measurements of pristine PVDF and composite membranes

	Membrane	1	2	3	4	5	Contact angle average (°)	Deviation Ref
	PMP+PVDF	97.4 89.8 98.2 97.7		96	2.99	[6]
	PTMSP+PVDF	82.3 82.5 80.3 80.9 90.1	83	2.75	[7]
	Teflon AF2400 +PVDF 103.4 113.6 113 116.2 115.8	112	3.6	[5]
	PVDF pristine	121.2 127 127.3 126.6		126	2.16	[8]

Table 3 :

 3 Pull-Off adhesion test measurements of pristine PVDF and composite membranes

	Experiment	PVDF pristine PMP	PTMSP T Teflon AF2400
	1	0.26	1.63	1.44	3.34
	2	0.2	1.45	1.48	3.27
	3	0.24	1.51	1.75	3.24
	Average (MPa)	0.2	1.5	1.6	3.3
	Deviation	0.02	0.07	0.13	0.04

Acknowledgments

David Brunello (david.brunello@univ-lorraine.fr) and Charly Koenig (charly.koenig@univlorraine.fr) and his team are gratefully acknowledged for their skillful contributions respectively to the online acquisition system and to the conception and fabrication of the experimental direct contact cell. The authors are very grateful to Région GrandEst and to Europe, programme ERASMUS (project EU-METALIC), for their financial support and grant for Dr. T. Eljaddi.

fixed on the sample support and it was pulled off automatically by the machine with a rate of 0.10 MPa/s. the same measurement was repeated three times with new samples. The mean deviation is small (Table 3).

Ethics Statement

This work reports original scientific data recorded at LRGP Laboratory. No extra partner has been involved. The contribution of all authors is well mentioned. This work does not involved the use of human subjects neither involved animal experiments.

None data collected from social media platforms were used.

CRediT author statement

Tarik

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article.