Lead Seals Research Articles

Flexible construction of demountable superfluid-tight electrical feedthroughs

This work introduces a new and simple design for electrical feedthroughs used in low-temperature experiments. Using readily available materials, one can effortlessly construct reliable electrical lead seals which have been proved superfluid-tight. Compared to the widely used Stycast-type epoxy sealing method in most low-temperature physics groups, our design offers increased flexibility and facilitates easy disassembly, all at a low cost.

Depth Evaluation of Subsurface Defects in Lead Seal Based on Accumulated Value Feature from Pulsed Eddy Current Signals

The lead seal is one of the piezoelectric cable components that is prone to failure. In this paper, the accumulated value of pulsed eddy current signals was utilized to characterize the subsurface defect depth of the lead seal for the safety of the lead seal in service. The characterization method of the defect depth was analyzed by the finite element model. The simulation results showed that the accumulated value feature had a linear relationship with the subsurface defect depth in a semilogarithmic coordinate system, and the linear fitting coefficient was 0.9982. The experimental results showed that the accuracy of the accumulated value feature in characterizing the subsurface defect depth was better than that of the peak value feature. Specifically, the maximum relative errors of the measurements were 12.51% and 9.07%, while the average relative errors were 5.83% and 8.00%, respectively.

Small Lead Seals And Sealing In Early Medieval East-Central Europe

Artykuł zawiera analizę stosowania plomb ołowianych we wczesnośredniowiecznej Polsce, jako metody kontroli handlowej i celnej w sytuacji kryzysu gospodarczego. Zwyczaj plombowania towarόw przez Piastów jest postrzegany jako transfer kulturowy z Rusi. Polskie plomby handlowe były używane równolegle z brakteatami guziczkowymi w okresie od połowy XIII do połowy XIV w. Wyobrażone na nich przedstawienia nawiązywały do znaków na brakteatach i znacznie różniły się od plomb typu drohiczyńskiego z terenów Rusi. Nadzwyczajna liczba odnalezionych w Drohiczynie plomb może być odzwierciedleniem przesunięcia szlaków handlowych wskutek konfliktów zbrojnych.

An imperial seal discovered at Argamum, Small Gate Sector (Scythia Minor)

Abstract In the archaeological campaign carried out in 2019, at Argamum, Small Gate sector, an imperial lead seal was found. On the obverse of the seal is stamped the face of an emperor, frontally depicted, with a beard, scepter on the left shoulder and two round fibulas placed on both shoulders. On the legend, arranged in a circle and partially preserved, we can read: Dominus Noster Theodosivs Avgustus. Imperial seals stamped with the effigy of Emperor Theodosius II have not been discovered until now in the territory of the province of Scythia Minor. The lead seal could be dated in the last two decade of the reign of the emperor Theodosius II.

The Byzantine Lead Seals at the Pera Museum

The collection of lead seals of the Pera Museum consists of 17 unpublished pieces, except for three lead seals (nos.1, 8, and 10) which are dated from the second half of the 7th century to the 13th century. Ten of the seventeen Byzantine lead seals of the Pera Museum collection mention the dignities and the offices of their owners. These offices range from the lower rank of a simple notary (no. 5) up to the highest office of the emperor himself (no. 9). There is only one seal related to the ecclesiastical administration, issued by a bishop (no. 2). Noteworthy are the seals of Georgios (no. 6), who has the uniquely attested office of an imperial apothekarios, as well as the 11th-century seal of Pharasmanes Apokapes, member of a notable Byzantine family of Armenian origin, by whom no other seals have been published so far. Another group of seals consists of the specimens (nos. 11-14 and possibly also no. 17) where only the name or the surname of their owner is mentioned. All these pieces are dated to the period between the second half of the 11th century and the 13th century. In the collection, there are two more iconographic seals (nos. 15-16) depicting on both sides holy figures without any inscription that mentions their owner, and finally, an unidentified seal (no. 17) (dated to the end of the 11th century).

Remarks on the collection of Byzantine lead seals of the Barber Institute of Fine Arts (University of Birmingham): mobility, networks, and identity in eastern Pontos

The Byzantine lead seals of the Barber Institute of Fine Arts number in total 146 pieces, mostly collected in the region of Trebizond. They offer valuable insights into the middle Byzantine society of the Pontos region, which despite its location on the easternmost borders was connected with other, even more remote, regions of the empire. The majority of these seals come from local officials and reflect their local preoccupations, perhaps as a backlash to the dominant culture of the capital. Fifteen selected pieces from the collection are published here and provided with commentary.

A Byzantine Lead Seal from Paphlagonian Hadrianopolis

A Byzantine Lead Seal from Paphlagonian Hadrianopolis

Parameter measurement of cable lead sealing using an eddy current system

Lead sealing is one of the key accessories for high-voltage cables and its quality directly affects the security and stability of such cables. In order to reduce the accident rate in power processing caused by lead sealing issues, it is necessary to carry out non-destructive testing and evaluation. Due to the bending surface of lead sealings, it is difficult to detect their conductivity and thickness accurately using existing eddy current (EC) testing methods. In this paper, measurements of conductivity and thickness for curved specimens are analysed and an accurate method is subsequently proposed. Firstly, the measurement methods of conductivity and thickness are established based on the transformer model. It is found that the conductivity and thickness can be detected using phase signature at high and low frequencies, respectively. Secondly, the influence of curvature on the phase signature is analysed and the conductivity and thickness measurements of lead sealing are corrected using curvature correction coefficients. Finally, an EC system is built and experiments are carried out to evaluate the novel methods. The results show that the methods achieve a good level of accuracy in detecting the conductivity and thickness of curved lead sealings.

Three remarkable Byzantine lead seals from a private collection

This study focuses on the publication of - and commentary on - three Byzantine lead seals that are part of a larger registered private collection. The first two are remarkable because of their owners' names, rarely attested in Late Antiquity and the Middle Byzantine period: Βιάτωρ / Viator (droungarios, date: ca. 650-700) and Genethlios (stratelates, date: ca. 750-825). The third, which belonged to a certain Ioannes, taboullarios (date: ca. 650-725), demonstrates a mixture of Greek and Latin symbols in a Greek inscription and, perhaps, is among the latest of this kind.

A RECENTLY FOUND BULGARIAN RULER SEAL FROM PLISKA

During the regular archeological excavations of site 41 in the Outer City of Pliska in the summer of 2021, a fragment of a lead seal was discovered, which turned out to be the first sphragistic monument of this archeological site. Obv.: In center, part of the facing bust of Christ within equal-armed cross behind head. Inscription between two borders of dots: : . . . . . . . . . . . . ΑΡXΟΝΤΑΒΟ. . . . . . . (Obr. 2а) Rev.: Heavily damaged bust of the Mother of God in the face. Her hands are placed in front of her breast in a praying posture. Her left hand is clearly visible. Around the image part of a circular inscription: . . . . . ΗΘΗΪωA . . . . . . . . . . . . . . . . . . (Obr. 2b). The preserved part of the inscriptions and the serious iconographic and epigraphic proximity of the molybdobull with the seals of "Michael Archon of Bulgaria" and "Simeon Archon of Bulgaria" give grounds to restore the circular inscriptions in the form: Obv.: [+ ×(ñéóô)S or + Ê(ýñé)å âïÞèç <ЙщЬнïх] Fñ÷ïíôá Âï[õëãáñßáò] Translation: “Christ or My God, aid John, archon of Bulgaria” Rev.: [+ È(åïôü)êå âï]Þèç <ЙщЬ[нïх Fñ÷ïнôá Âïхëãáñßáò] Translation: “O Mother of God, aid John, archon of Bulgaria” The iconographic and paleographic data of the fragmented press give grounds for it to be dated with a great deal of certainly in the second half of the ninth century.

Ołów i władza: plomby Rurykowiczów i Piastów w Europie środkowo-wschodniej

The article considers the economic and political use of small lead seals (tag seals) to validate different kinds of social relations in early medieval Poland and Rus’. Originated in Antiquity, the practice of sealing peaked in Byzantium from where it spread to Early Rus’. This is reflected, for example, in the use in late 11th-late 14th centuries of small lead seals referred to as the “Drohiczyn type”. In this paper I put forward an opinion that not all the early medieval small lead seals should be attributed to “coinless economy”. A study of the corpus of small lead seals from Drohiczyn and Czermno, and finds from Mazovia, has identified a group with iconography identical to the Polish Hohlpfennig, suggesting they were commercial-customs small lead seals used by the Piast dynasty, contemporary with the bracteates introduced in the first half/mid-13th-early 14th centuries. The extraordinary number of small lead seals found in Drohiczyn possibly reflects the outstanding position of the town in the Eastern and Central European relationships as well as a short-term relocation of trade routes leading north, caused by the military conflicts of the 1240-1280s in the upper course of the Western Bug. The practice of sealing could have been introduced by Conrad of Mazovia to Poland from Early Rus’. Subsequently, the small Polish lead seals might have contributed to the emergence of lead cloth seals in Western Europe as part of a cultural transfer.

Research on Deep Defect Detection Method of Cable Lead Sealing Based on Improved Pulsed Eddy Current Excitation

In order to reduce power failures caused by lead sealing defects, it is necessary to carry out nondestructive testing of cable lead sealings. However, previous studies have focused on the detection of surface and near-surface defects of lead sealings. Thus, an improved pulsed eddy current detection (IPECD) method is introduced to detect the deep defects of cable lead sealings (with depths ranging from 6 to 12 mm), and the frequency range selection principle and the optimization method of initial phase angles of different frequency components of IPECD, used to maximize the peak value of the excitation signal, are first explained in detail. Then, the detection sensitivities of the deep defects before and after the optimization are compared and analyzed based on a simulation. Finally, using the IPECD method, experiments are conducted to study the effects of the defect depth on features of the lift-off point of intersection and the zero-crossing time, enhancing the foundation for the prediction or rapid detection of the depth of lead sealing defects.

Drohiczyn-type Small Lead Seals with the Image of a Bird from the Collection of the National Museum in Krakow. Old Ruthenian Sigillography Versus Early Piast Numismatics / Plomby typu drohiczyńskiego z wyobrażeniem ptaka w kolekcji Muzeum Narodowego w Krakowie. Staroruska sfragistyka versus wczesnopiastowska numizmatyka

The rich collection of the Numismatic Cabinet of the National Museum in Krakow (MNK) includes special sigillographic artefacts, i.e. Drohiczyn-type small lead seals. The collection contains specimens with various iconographic representations, including small seals with images of birds. Similar small seals are known from archaeological excavations conducted in Mazovia. Interestingly, some images impressed on the small seals have analogies with representations on Piast coins from the 12th and 13th century. It is highly likely that the small seals with images of birds are local issues from Mazovia. This is indicated by a characteristic type of bird representations, most probably eagles. This would mean that they were an adaptation of the Ruthenian idea of using small lead seals but with local Piast symbols.

Late Byzantine sigillographic evidence from Cappadocia: lead seals from Kırşehir with a unique overstruck example

Abstract This short essay presents four 11th century A.D. Byzantine lead seals, all of which are stored in the local museum of Kırşehir, in ancient Cappadocia, which is located today in southeastern part of central Turkey. The Museum of Kırşehir owns a minor collection of at least 13 Byzantine lead seals and a selection of four unpublished seals is being presented, which were sold to the museum by local antique dealers from the Turkish provinces of Kırşehir and Aksaray. All of the seals are dated to the late 10th and early or mid-11th centuries A.D. No. 1 is an overstruck seal with a parallel piece which is a very unique specimen and raises some sigillographic and prosopographic questions. The three other seals are discussed with a focus to Byzantine dignitaries and their offices during the 11th century A.D. The descriptive discussion at the beginning briefly touches upon a some geographical and historical issues related to Kırşehir and its museum. This small collection of seals provides important evidence regarding the seal owners and the administration of the themes of Cappadocia and Charsianon on the eastern border of the Byzantine Empire. The paper offers a substantive analysis of the material, with a discussion and resolution of the sigillographic inscriptions and imagery.

The Title Hierarchy of the Last Komnenoi and the Angelos Dynasty – from Sebastohypertatos to Sebastokrator

The system of dignities introduced by Alexios I Komnenos was an answer for the need of a new reformed title hierarchy, adequate for aristocratic model of exercising power. It served as a clear manifestation of the special privileged position of emperor’s kinsmen. The titles granted to those relatives and affines can be traced accurately up to the reign of Manuel I. So far, however, little space has been devoted to the analysis of that system during the Angelos dynasty.It is often generally assumed following Niketas Choniates testimony, that the title hierarchy in the late 12th century suffered certain loss of value or inflation. It is worth taking a closer look at this process, on the example of the titles traditionally granted to the closest family members, at the courts of Andronicus I Komnenos and the Angeloi. I would like to focus particularly on those dignities, that at the time of the Komnenoi were given to the emperor’s siblings and his sons-in-law – from sebastohypertatos to sebastokrator. That part of the title hierarchy was much closer to a ruler, making it easier to trace.The basic problem encountered by researchers of this period is the small number of sources, not allowing for full reconstruction of the title hierarchy. However, very limited information found in the written sources can be complemented by aristocratic lead seals, which often included the dignity of their owners.From such an analysis emerges a picture of a steady evolution of the Komnenian system. The emperors of the late 12th century adjusted court dignities to need at hand. Yet that process doesn’t seem to diminish significantly the value of the highest titles.

Новая свинцовая печать Адриана Комнина, протосеваста и великого доместика схол Запада, обнаруженная в районе крепости Русокастро в Юго-Восточной Болгарии

ntroduction. The present article is a primary publication of a newly discovered sphragistic artefact from the area of the medieval fortress of Rusokastro, which was acquired by the Regional Historical Museum in Burgas in 2019. Methods. In their entirety, the Byzantine lead seals are an important primary and reliable source of information on various aspects of Byzantine history. Byzantine seals are especially important from the perspective of prosopography. First of all, they are invaluable evidence of individuals who, in one way or another, participated in the social and political life of the Byzantine Empire. Therefore, the discovery of each new sphragistic monument is of great importance and the available information must be carefully analyzed. Analysis. This interesting artefact is a lead seal of the brother of the Byzantine emperor Alexius I Komnenos (1081–1118), Adrian Komnenos as a protosebastos and megas domestikos of the entire West. The obverse depicts Saint George, nimbate, standing, facing forward, holding a spear in his right hand, and resting his left hand on a shield. Inscription in 7 lines within dotted border on the reverse: + Κ(ύρι)ε β(οή)θ(ει) τῷ σῷ δούλῳ Ἀδριανῷ (πρωτο)σεβαστῷ (καὶ) μ(ε)γ(άλῳ) δομ[ε]στίκῳ πάσης Δύσεως τῷ Κομνην(ῷ). The seal dates from the end of the 11th century. Results. This new Byzantine lead seal, described in this article, increases the number of medieval sphragistic finds in the Rusokastro area, which belong to an undeniably wide chronological range – from the second half of the 8th century to the beginning of the 12th century. Thus, the number of lead seals from the area of Rusokastro grow to six, five of which are Byzantine and one is a Bulgarian imperial seal.

Middle and Late Byzantine sigillographic evidence from western Anatolia: eighth- to early twelfth-century lead seals from Bergama (ancient Pergamon)

This article presents 19 lead seals from the Museum of Bergama (ancient Pergamon), dating from the early eighth to the early twelfth century. We offer a descriptive catalogue of these Middle and Late Byzantine seals preserved in a western Turkish museum. The owners of these seals were primarily ecclesiastical, legal or military dignitaries who were probably active in Pergamon, in southwestern Mysia, Aeolis or Lydia. The catalogue is followed by an appendix on a Byzantine magical amulet.

Conservation and Restoration of Molybdobulls from the Fund of the Archaeological Museum "Veliki Preslav"

Archaeological Museum "Veliki Preslav" has over 110 years of history. It was founded as part of the Archaeological Society "Ticha" on October 26, 1906 and lasted in this form until 1949. Then the museum was provided with a large building next to the church monument "St.St. Cyril and Methodius", not far from the Preslav Palace. In 1981, the museum was moved in a new purpose-built building, where it still welcomes history lovers from around the world. At the permanent exhibition you can see epigraphic monuments that testify to the spread of literature, as well as examples of artistic crafts, showing the rise of the Bulgarian state. The most striking examples of this are the Preslav golden treasure and objects of the Preslav white clay pottery. More than 35,000 objects are stored in the museum funds, 1700 of which are presented in the exposition hall. The most significant Preslav samples have been included in dozens of international exhibitions, in hundreds of scientific publications, film and media productions. Today Veliki Preslav has its own archaeological museum with a magnificent exposition, visited annually by tens of thousands of Bulgarian and foreign tourists. The museum's collections most fully present the phenomenon of the Golden Age and illustrate the place of Simeon's capital as a leading center of Slavic writing, art and art crafts in Southeast Europe in the ninth and tenth centuries. More than 570 sphragistic monuments are stored in the museum's fund. For most of them there is accurate information about their location, which makes them full sources for Bulgarian history from IX - XI century. In 1978, a team of archaeologists led by Ivanka Akrabova-Zhandova, exploring the area in the southeastern part of the inner city of Preslav, discovered a building with massive foundations and preserved squares of construction, which plan resembles a pagan temple or shrine. As a result of the excavations, which continued in the following years, more than 500 molybdobulls, 250 lead cores and three molds for their casting have been discovered. These findings testify to the administrative nature of the building, in which not only the correspondence was stored, but it was also sent. Therefore, we are talking about an chancellery that served the local Byzantine strategists. Thanks to the seals found there, we found the names of 17 strategists of Preslav in the period 971-1059. The molybdobulls also present the names of persons who wrote to the local strategist. Almost all social groups in the empire are represented - from the emperor himself to the common spatary. In 2019, 50 lead seals were included in the exhibition "At the Gates of the Royal Court. Treasures of Veliki Preslav", which was opened at the Archaeological Museum in Sofia. In 2020, the project "Conservation and restoration of molybdobulls from the Strategy in Great Preslav" was completed. This project was implemented by the Archaeological Museum "Veliki Preslav" in partnership with National Archaeological Institute with Museum at the Bulgarian Academy of Sciences. 100 of the most affected molybdobulls have undergone conservation and restoration. Restoration activities are a necessary step that must be carried out before the digitalization of the sphragistic fund.

Assembly Quality Detection Based on Class-Imbalanced Semi-Supervised Learning

Due to the imperfect assembly process, the unqualified assembly of a missing gasket or lead seal will affect the product’s performance and possibly cause safety accidents. Machine vision method based on deep learning has been widely used in quality inspection. Semi-supervised learning (SSL) has been applied in training deep learning models to reduce the burden of data annotation. The dataset obtained from the production line tends to be class-imbalanced because the assemblies are qualified in most cases. However, most SSL methods suffer from lower performance in class-imbalanced datasets. Therefore, we propose a new semi-supervised algorithm that achieves high classification accuracy on the class-imbalanced assembly dataset with limited labeled data. Based on the mean teacher algorithm, the proposed algorithm uses certainty to select reliable teacher predictions for student learning dynamically, and loss functions are modified to improve the model’s robustness against class imbalance. Results show that when only 10% of the total data are labeled, and the imbalance rate is 5.3, the proposed method can improve the accuracy from 85.34% to 93.67% compared to supervised learning. When the amount of annotated data accounts for 20%, the accuracy can reach 98.83%.

Minima Epigraphica: On Some Roman and Byzantine Inscribed Objects from Elaiussa Sebaste (Cilicia)

This article aims to present some inscribed small finds from former excavations carried out in the years 2006-2011 at Elaiussa Sebaste in Cilicia, under the auspices of the University of Rome, Sapienza. An inscribed base of a glass bottle, a lead seal, two glass weights, a bronze ring and an inscribed potsherd will be analyzed, so as to give new significance to these items that were until now neglected. All the objects pertain to the Late Roman or Early Byzantine period, mainly from the sixth until the mid-seventh century AD. Even if related to various different typologies, these inscribed finds have some common characteristics and shed light on several aspects of public and private life in a port city of southern Anatolia.