Original Technique Research Articles

The Extended Corset with Bra Strap: Refinements in the Corset Trunkplasty Technique.

The corset trunkplasty was introduced by Moya et al. in 2009 (Moya and Sharma inJPRAS 62:56-64, 2009). It is a modified abdominoplasty technique that combines vertical and high lateral incisions to achieve an hourglass shape in post-massive weight loss patients. Like the traditional fleur-de-lis abdominoplasty (Dellon in Aesth Plast Surg 9:27-32, 1985) it results in a midline scar, as well as additional transverse breast fold scars, however the lack of tissue undermining reduces the risk of skin necrosis and wound-healing problems. Since its original description, it has been promoted as a practical, cost- and time-efficient procedure in the massive weight loss patient population (Loh et al. in J Plast Reconstr Aesthet Surg 74:2303-2310, 2021). The senior author (PM), has performed 43 extended corset trunkplasties since 2018. Drawbacks of the original technique include migration of the midline scar over time, stretch and enlargement of the umbilicus giving an unnatural appearance, high, unsightly lateral scars, upper back skin redundancy relative to the anterior skin tightening, and persistence of tissue excess in the flanks and lower back. Over time, the senior author has refined his technique to overcome these post-operative complications and thus improve overall aesthetic appearance and patient satisfaction.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

PETAL – LIKE OTOPLASTY IN THE TREATMENT OF PROTRUDING EARS

Introduction. Approximately 5% of humanity suffers from inborn protruding ears, and usually this condition causes marked psychosomatic disorders. Despite years of experience gained in aesthetic surgery, optimal technique of otoplasty is yet to be elaborated. The Aim of the Research. To develop a method of surgical correction of congenital bulging ears in order to optimize the immediate and long-term results of otoplasty. Material and methods. We have analysed the outcomes of 120 patients operated for congenital protruding ears at Lviv City Cosmetologic Hospital between 2020 and 2023. Distance between mastoid process and the concha exceeding 20 mm, and auriculo-cephalic angle over 30° were used as objective criteria of protruding ears. Surgical improvement of tall concha and increased auriculo-cephalic angle were identified as key vectors in elaboration of the original otoplasty technique. Results of the Research. With local anaesthesia, an S-shaped incision is made to the depth of perichondrium of posterior surface of the cartilage of the ear. Once subcutaneous dissection is completed, preoperative markup is transferred with injection needles from anterior surface to posterior surface of the conchal cartilage. A full depth arch-shaped incision of conchal cartilage is made. Perichondrium and skin of anterior surface of the concha are mobilized with a raspatory, from the chondral «petal» to the margin of external meatus. Basis of the chondral «petal» is dissected by 2/3 of its depth along the vertical axis between the pedicle of the helix, and the antitragus. In order to reliably fix the auricula, the cartilage is stitched to the mastoid process with three mattress sutures on the ventral surface of the «petal». Finally, excessive skin is carefully resected, and the wound is closed with continuous suture, with dead space elimination for hematoma prevention. Our technique has the following significant advantages: Unique conchal cartilage is kept entirely, therefore it can be used as auto-transplant in the future. The technique does not significantly affect the rheology of auricula. With this technique correction and modification of antihelical curve and radius is possible; if necessary, width of auricula can be corrected, and auricular height to width ratio can be modified. The proposed «petal» technique significantly reduces the rate of postoperative complications, such as recurrent protruding ears. Postoperatively, the size of external meatus is not reduced, hence no hearing deterioration. The outcomes of the technique we have developed were assessed 6 months after otoplasty as good, satisfactory and unsatisfactory. Good outcome: preservation of symmetry and anatomical «standard» of both auriculas, no recurrence throughout follow-up, and no impairment of sensation in the external ear. Satisfactory outcome: anatomical «standard» of the organ is preserved, with permissible error of up to 3 mm in the symmetrical points on the right and left auriculas, not requiring additional correction. Conclusions. 98 (81,3%) patients operated by the proposed «petal» technique assessed their otoplasty outcome as good, 17 (14,3%) of patients assessed the outcome of surgery as satisfactory. 5 (4,3%) patients were not satisfied with the outcome of surgery. These patients were operated during the early period of development of the technique.

Efficient Estimation of Synthetic Indicators for the Assessment of Nonlinear Systems Quality

The availability of synthetic indicators of the degree and type of nonlinearity in systems is used in various fields to assess system quality or to highlight possible malfunctions. Different distortion or damage indexes are synthetic measures designed (and standardized) to evaluate the frequency trend of specific aspects resulting from the nonlinear behavior of the system under consideration. The different measures of deviation from linear behavior quantitatively consider the system and its nonlinearity characteristics; they were defined according to practically feasible measurement methodologies and the various aspects of the system’s nonlinearity that needed to be highlighted. In parallel, techniques for representing and modeling nonlinear systems have been defined, capable of describing the system in a more general way, attempting to capture its input–output characteristics by varying the level of stress to which the system is subjected. Numerous modeling techniques have been proposed, aimed at representing the nonlinear behavior of physical devices. In this paper, after an extensive description of the Hammerstein model identification technique based on swept sinusoidal signals, we show how the nonlinear model of the system can be used to obtain accurate estimates of the parameter aimed at describing the nonlinearity characteristics of the system. This extensive description makes it possible to point out that the same Hammerstein model can be obtained not only from a single type of excitation, but it is shown that the identification technique can be extended to input signals of different types. The description of the method also makes clear the motivation behind the introduction of the proposed original technique for estimating, from a single measurement, the model parameters of the nonlinear system—and from these the synthetic estimators—relative to multiple values of the input signal amplitude, thus enabling a considerable increase in the estimation efficiency of these parameters. The proposed technique is verified with both synthetic and laboratory experiments, demonstrating the effectiveness of the method in evaluating nonlinear system parameters, distortion estimates, and parameters defined for an early detection of defects of the structure.

A novel homological approach for the comprehensive study of nonstoichiometric oxide with exceptional oxygen mobility

Actual work devoted to the development of a novel homological approach for describing the kinetic properties of grossly nonstoichiometric oxides ABO3-δ with perovskite structure. The approach consists in considering such oxides having different oxygen stoichiometry 3-δ as chemical homologues involved in the same oxygen exchange reaction and forming a continuous series in δ. The proposed approach is considered using the oxide with exceptional oxygen mobility Ba0·5Sr0·5Co0·8Fe0·2O3-δ (BSCF). The kinetic properties of BSCF were studied by new method of the oxygen partial pressure relaxation. The equilibrium properties of BSCF were reported earlier and obtained by original technique of the quasi-equilibrium oxygen release. The power law dependence of the kinetic parameters on the equilibrium oxygen partial pressure is considered as the consequence of linear free energy relationship similar to the Brønsted-Evans-Polanyi relation.

Bilateral transobturator hysterosuspension using titanium tape-shaped mesh implants in women with apical prolapse of the internal genitalia

BACKGROUND: Pelvic organ prolapse is a common pathology with several relapses of the disease after surgical treatment using exclusively self-tissues, which necessitates the development of new surgical techniques using durable and biological inert materials. AIM: To evaluate the effectiveness and safety of an original surgical technique for apical prolapse correction in patients of reproductive and pre- and postmenopausal age. MATERIAL AND METHODS: Twenty-nine patients were examined and operated on using a developed original technique with the use of narrow tape-shaped titanium mesh implants. RESULTS: Follow-up was conducted at 1, 6, 12, and 24 months postoperatively. Comparison of patient survey indicators in the pre- and postoperative periods showed an improvement in the patients’ quality of life and an increase in their social and sexual activity. During the first month, 15 (51.7%) patients reported intermittent pulling pains in the perineal and/or inguinal–femoral folds, and 4 (13.8%) reported frequent urination. Clinical examination revealed complete preservation of the surgical correction of prolapse in all patients. Gynecological and rectal examinations and transperineal and transvaginal echography did not show displacement of pelvic organs or titanium implants. Mesh-associated complications were not noted during the observation period. CONCLUSION: The developed original technique for surgical correction of second-degree apical prolapse with the use of narrow ribbon-shaped titanium mesh implants is effective and safe. This is evidenced by the normalization of the uterus position in the pelvis, absence of displacement of pelvic organs in the near and distant postoperative periods, and absence of mesh-associated complications during the observation time.

From fashion to sustainability

Sustainability issues are increasingly influencing firms’ decision making, leading to the creation of new business models for finding solutions to environmental and societal challenges. is work aims to explore what is the role played by industrial districts in firms’ orientation towards sustainability. It implements a Propensity Score Matching technique on a novel datatabase with information on 1300 Italian fashion firms. eir sustainability orientation is measured using the Quantitas Intelligent Business Analyzer (QIBA), an original Natural Language Processing-based data mining technique, which allows scraping firms' websites and analyzing their content adopting a Term Frequency–Inverse Document Frequency weighting scheme. Findings suggest the existence of a sustainability-driven industrial district effect, i.e. a positive association between the sustainability orientation of fashion firms and their localization in industrial districts.

LIDAR adaptive parameters selection and target pointing control for close-proximity space operations

This paper deals with advanced Guidance, Navigation and Control (GNC) functions required to enable autonomous and safe operations of a chaser spacecraft in close-proximity to an uncooperative space target, as in Active Debris Removal or On-Orbit servicing scenarios. Specifically, it presents an original approach to autonomously and adaptively select the field of view and resolution of a scanning LIDAR to improve both state estimation accuracy and computational efficiency of a LIDAR-based relative navigation system. In general, the correct operation of such system is also determined by the capability to keep the boresight axis of the relative navigation sensor aligned with the target geometric center. To address this task, an original control technique, based on the sliding-mode formulation and relying on a reduced attitude representation, is proposed. This control scheme is also compared to state-of-the-art PD and PID approaches in terms of pointing accuracy and control effort. The proposed techniques have been numerically validated in a simulation environment integrating the chaser attitude control and the LIDAR-based relative navigation functions in a closed-loop architecture. The simulation environment realistically reproduces the generation of LIDAR-based point clouds, and the spacecraft relative dynamics in close proximity. Results show that the adaptive selection of the LIDAR operational parameters improves the relative navigation performance, while the proposed sliding-mode control guarantees higher pointing accuracy than PD and PID control approaches.

Analysis of Two Oncological Drugs Futibatinib and Capivasertib via Ion-Pairing With Eosin Y as a Spectrofluorimetric and Spectrophotometric Probe.

Using spectroscopy, two quick and sensitive analytical methods based on eosin Y ion pairing were developed and assessed in order to determine capivasertib and futibatinib with high selectivity and sensitivity. The quenching impact of futibatinib or capivasertib on the eosin Y's fluorescence at a pH 3.8 and 3.3 for futibatinib and capivasertib, respectively, in 0.1-M acetate buffer solution was observed using two spectrofluorometric techniques. These techniques are regarded as the original spectrofluorometric techniques for the assay of futibatinib and capivasertib. For futibatinib and capivasertib, the quenching effect on fluorescence was ranged from 100 to 1000 and 150 to 1500 ng mL-1, respectively. The absorbance of the generated ion-pair was measured using two different spectrophotometric methods at 550 nm in aqueous buffered solutions with pH values of 3.8 and 3.3 for futibatinib and capivasertib, respectively. In the concentration range of 1.0-10.0 and 2.0-10.0 μg mL-1, Beer's law was followed. The four approaches were applied to the analysis of dosage forms with a high percent recovery successfully, and they were assessed in compliance with ICH guidelines.

Anterior Distal Femoral Hemiepiphysiodesis Using Coronally Oriented 8-plates for the Correction of Fixed Knee Flexion Deformities in Children-Preliminary Results.

The original technique for guided growth of the distal femur for correction of pediatric fixed knee flexion deformities (FKFDs) involves the utilization of two 8-plates inserted on either side of the trochlear groove, a technique that has been frequently linked to the development of persistent postoperative knee pain and crepitus. The present study aimed to assess the preliminary results of a novel technique where the two 8-plates are fixed in the coronal plane, one on each of the medial and lateral surfaces, so that they occupy the anterior part of the distal femur. Our study was a prospective case series that included cases with FKFD of >10 degrees in children with at least 12 months of predicted growth remaining. The preoperative knee flexion contracture angle was documented. The surgical procedure entailed the insertion of 2 coronally oriented 8-plates on the medial and lateral surfaces of the distal femur as anterior as possible to the axis of the femur without encroachment on the trochlear groove. The duration of time required to attain full knee extension and any complications encountered were recorded. Wilcoxon signed-rank was used to compare the preoperative and final contracture angles. The level of statistical significance was set at P <0.05. Thirteen knees in 8 patients (6 boys and 2 girls) were included. The median age was 11 years (6 to 14). There was a significant improvement in the FKFD for the whole cohort from 25 degrees (14 to 42) to 0 degrees (-9 to 8), P <0.05. The median rate of correction was 2.0 degrees/month (0.9 to 5.8). The time till full correction was 14 months (4 to 25). Postoperative knee pain and metalware-related complications were not reported by any patient during follow-up. Guided growth of the distal femur using coronally oriented 8-plates is an effective procedure for the treatment of FKFDs in children. This modified technique may achieve faster correction while minimizing the risk of postoperative knee pain compared with the conventional technique. Level IV-case series.

Feasibility of a less invasive supercharged end-to-side anterior interosseous nerve to ulnar motor nerve transfer.

The object of this study was to perform an anatomical dissection of Thiel-embalmed specimens in a step-by-step procedure, to establish a 'safe zone' in which to perform a less invasive supercharged end-to-side (SETS) anterior interosseous nerve to ulnar motor nerve transfer without tension and to demonstrate its feasibility. The sample size was calculated with a 5 mm error to reach a 95% confidence interval. Dissection was performed in 15 specimens and the 'safe zone' was established between 40 and 90 mm proximal to the pisiform. Several surgical tips are recommended to help complete the procedure. A reproducible 'safe zone' was found for performing a SETS anterior interosseous to ulnar motor nerve transfer with 95% certainty, reducing soft tissue damage and enhancing the original surgical technique.

Knowledge mapping of induced membrane technique: a scientometric study from 2004 to 2023

BackgroundThe induced membrane technique (IMT) is a two-step procedure used for reconstructing segmental bone defects in the limbs. The osteogenic mechanism after bone grafting using IMT remains unclear, and efforts to modify the original techniques are limited to the investigative phase. Therefore, reviewing existing knowledge and identifying hotspots and new trends in IMT is critical.MethodsWe retrieved reviews and articles associated with IMT published between 2004 and 2023 from the Web of Science Core Collection (WoSCC). The keywords included induced membrane technique, guided bone regeneration, bone defect reconstruction, bone graft, stem cells, Masquelet technique, management of bone defects, and scaffold. HistCite, VOSviewer, CiteSpace, and R-bibliometrics were used for scientometric analysis.ResultsA total of 1019 publications from 374 academic journals with 33,995 co-cited references by 2,331 institutions from 65 countries or regions were included. China (n = 235) and the United States (n = 215) were the most productive countries, with Shanghai Jiao Tong University producing the most number of publications (n = 18). Journal Injury [co-citations = 1774; impact factor (IF) 2022 = 2.5] published the most manuscripts, while Masquelet AC and Giannoudis PV published literature with a significant influence on IMT, showing more co-citations (n = 727; n = 355). Two preface hotspots of IMT focused on investigating the microscopic mechanism (such as the membrane supporting graft-to-bone union and the role of inflammatory cells) and developing new techniques to improve IMT (such as bone tissue engineering and new drugs).ConclusionThis study comprehensively reviewed the literature about IMT published in the last 20 years using qualitative and quantitative methods, providing valuable information for researchers investigating IMT.

External fixation of an internal aortic annuloplasty device: advancing the technique.

We present a modified technique of Hemispherical Aortic Annuloplasty Reconstructive Technology (HAART) 200 annuloplasty ring implantation in bicuspid aortic valve morphology by external fixation of the looping sutures to avoid common complications associated with the original implantation technique. Preliminary results are promising and should be confirmed in subsequent multicentre studies.

Two early cinquecento Renaissance polyptychs by Antonio de Saliba on Sicily and Malta: an art-historical and scientific investigationtion

This study focuses on two Renaissance polyptychs that were produced by Antonio (1466/7–c. 1535) and Giovanni de Saliba (doc. 1461–1517?), referred to in this study as the Taormina Polyptych (1503–04) and the Rabat Polyptych (1510–15). Through art-historical research and scientific analyses, this study sheds light on their original visual completion and manufacturing techniques. The Taormina Polyptych, located at the Cathedral of St Nicholas of Bari in Taormina, Sicily, underwent thorough on-site examination, revealing details overlooked in prior studies. A two-dimensional digital reconstruction, the creation of which was aided by early 20th century photographs, provided insights into its original appearance. The Rabat Polyptych, once situated in the Franciscan Observant Church in Rabat, Malta, faced dismemberment in 1785, leading to challenges in reconstruction. By analysing historical documents and employing digital reconstruction techniques, the original framework was hypothesised. Scientific studies, including histological and stratigraphic analyses of wood and pigment samples respectively, carried out on two newly discovered predella panels from the Rabat Polyptych, provided insight on Antonio de Saliba's techniques. The digital reconstructions and insights into manufacturing techniques contribute to scholarship on Antonio’s works in the context of Sicilian Renaissance art.

Structural Study on the Novel Plasmonic Optical Materials with Copper Selenide Nanoparticles

Background: Semiconductor-doped materials have been treated actively throughout the last decades and continue to be of great interest because of the challenges of the features due to various nanosize effects. Among other semiconductors, copper chalcogenides demonstrate the interesting plasmonic properties in line with quantum confinement effects provided by the size factor. Objective: This study aims to study the structural and optical features of the sol-gel-derived silica glasses with copper selenide nanoparticles, demonstrating the appearance of the plasmonic light absorption in the near IR range. Method: The samples under study were fabricated through an original sol-gel technique, which realized the simultaneous synthesis of copper selenide and sintering of mesoporous silica. The copper selenide glasses were characterized with X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and optical absorption spectroscopy. Results: Formation of nanocrystalline Cu2-xSe particles of the size range from 10 nm through 100-150 nm is established with XRD and TEM techniques. The principal optical properties are presented by the featured absorption in the visible and near-IR ranges. Eg was evaluated for the direct transitions in the range of 2.10-2.36 eV. The plasmonic resonance in the nanoparticles due to increased carrier concentration originated by intrinsic deficiency of Cu2-xSe nanoparticles with variable stoichiometry. Its energy can be controlled by the Cu/Se ratio in the synthesis procedure. Conclusion: The silica sol-gel glasses with copper selenide nanoparticles were fabricated and characterized by XRD and TEM methods, and their optical absorbance spectra were investigated. The principal optical properties are presented by the featured absorption in the visible and near-IR ranges: the steplike proper absorption of the semiconductor particles characterized by Eg and the intense near-IR band is associated with the localized plasmonic resonance in the nanoparticles due to increased carrier concentration.

Update on minimally-invasive treatment of Achilles tendon rupture

Percutaneous and minimally invasive suturing techniques are very important in the treatment of acute Achilles tendon ruptures because they combine the advantages of surgical treatment (low re-rupture rate) and non-opervative treatment (low risk of complications). In the authors' approach, the percutaneous, peritendineum-preserving technique with the Dresden instrument has proven itself as astandard treatment for 20years. Strict adherence to the original Dresden technique with posteromedial incision and subfascial preparation is crucial for the safe avoidance of the sural lesions regularly reported in percutaneous procedures. The rupture zone and the peritendineum should not be opened. By adding athird suture and using non-absorbable suture material, stability comparable to the open Krackow suture technique is achieved. Functional aftertreatment with protection in aspecial boot and appropriate supervision of the patient aims at early rehabilitation while minimizing the risk of re-rupture or loss of tension. The focus of future efforts should be to further improve treatment results through individualized postoperative treatment adapted to tendon healing.

Boundaries in Kinematic Alignment: Why, When, and How.

The use of alternative alignments in total knee arthroplasty (TKA) has recently been increasing in popularity: many of these alignments have been included in the broad spectrum of "kinematic alignment." This alternative approach was recommended to increase patients' satisfaction since many studies based on patient-reported outcome measures (PROMs) showed that every fifth patient is not satisfied with the surgical outcome. In fact, the original kinematic alignment technique was designed as a "pure resurfacing" technique, maintaining the preoperative axes (flexion-extension and axial rotation) of the knee. In adjunct, many new classifications of the preoperative limb deformity have been proposed to include a large range of knee anatomies, few of them very atypical. Following those classifications, many surgeons aimed for a reproduction of unusual anatomies putting in jeopardy the survivorship of the implant according to the classical "dogma" of a poor knee kinematics and TKA biomechanics if the final hip-knee-ankle (HKA) axis was not kept within 5 degrees from neutral. This article reviews the literature supporting the choice of setting alignment boundaries in TKA when surgeons are interested in reproducing the constitutional knee anatomy of the patient within a safe range.

Efficient Federated Learning Using Dynamic Update and Adaptive Pruning with Momentum on Shared Server Data

Despite achieving remarkable performance, Federated Learning (FL) encounters two important problems, i.e., low training efficiency and limited computational resources. In this paper, we propose a new FL framework, i.e., FedDUMAP, with three original contributions, to leverage the shared insensitive data on the server in addition to the distributed data in edge devices so as to efficiently train a global model. First, we propose a simple dynamic server update algorithm, which takes advantage of the shared insensitive data on the server while dynamically adjusting the update steps on the server in order to speed up the convergence and improve the accuracy. Second, we propose an adaptive optimization method with the dynamic server update algorithm to exploit the global momentum on the server and each local device for superior accuracy. Third, we develop a layer-adaptive model pruning method to carry out specific pruning operations, which is adapted to the diverse features of each layer so as to attain an excellent trade-off between effectiveness and efficiency. Our proposed FL model, FedDUMAP, combines the three original techniques and has a significantly better performance compared with baseline approaches in terms of efficiency (up to 16.9 times faster), accuracy (up to 20.4% higher), and computational cost (up to 62.6% smaller).

A novel weight index-based uniform partition technique of multi-dimensional probability space for structural uncertainty quantification

Accurately and efficiently achieving the uncertainty quantification of engineering structures is a challenging issue. The direct probability integral method (DPIM) provides an effective pathway to address this issue. However, the key partition technique via Voronoi cell of DPIM requires a prohibitive computational burden for multi-dimensional probability space. Moreover, due to the distributed nonuniformity of representative points, the accuracy of DPIM with the partition technique via Voronoi cell (DPIM-Voronoi) for obtaining the response probability density function (PDF) of structures with multi-dimensional probability space still needs to be improved. To this end, a novel weight index-based uniform partition technique is proposed in this study. This technique can generate uniformly distributed representative points and calculate their assigned probabilities using the weight indexes of representative regions. This feature ensures that the representative points can fill the probability space in a highly uniform manner, and avoid the resource-consuming calculation process of assigned probability by Monte Carlo simulation in the original partition technique via Voronoi cell. Based on the proposed technique, DPIM with a Weight index-based Uniform partition technique (DPIM-WU) is developed. Compared to DPIM-Voronoi, the advantages of DPIM-WU include: (1) improving the computational accuracy of response PDF for structures with multi-dimensional probability space, especially in the tail region, leading to improved accuracy of the dynamic reliability; (2) remarkably reducing the computational cost, with minimal computer memory required for the partition process of multi-dimensional probability space; (3) enhancing the robustness to the number of representative points. These advantages are verified through the stochastic response and dynamic reliability analyses of four typical examples, including the 5-story buildings, dry friction system, cylinder structure, and adjacent buildings with pounding motion. Notably, in the stochastic pounding response analysis of adjacent buildings, a stochastic P-bifurcation occurs as the coefficient of variation of the structural parameters decreases.

The Ilizarov Technique: A Dynamic Solution for Orthopaedic Challenges.

The Ilizarov technique is one of the most important tools that is currently employed in bone reconstruction surgeries. Its inception dates back to the mid-20th century and involves various bone reconstruction methodologies implemented using a circular external fixator system devised by G. A. Ilizarov. The key advantages of this approach include the generation of viable new bone via distraction osteogenesis, high union rates, and the functional utilization of the limb during the treatment process. The exploration of distraction osteogenesis phenomenon triggered by tensile stress with the Ilizarov device served as a catalyst for progress in bone reconstruction surgery. Subsequently, the original technique has been utilized alongside several adaptations resulting from the introduction of novel fixation tools and methods of their application, such as hexapod external fixators and motorized intramedullary lengthening nails. It is crucial to possess a precise comprehension of the Ilizarov principles of deformity correction in order to effectively utilize this fixation system. In this article, we will discuss the history of Ilizarov frame, the basic sciences behind it, the mechanical principles governing its use, and the clinical application of the fixation system in our daily practice.

Characterization of corrosion mechanism and traditional soldering treatment of a composite bronze lamp from the Greco-Roman period of Egypt

This paper presents a study of treatment by soldering for a unique bronze oil lamp combined with Eros and dog figurines. In this object, there are two types of soldering; the first is ancient, used to join the three pieces together, and the other is used in conservation treatments to stop the degradation of the object. Soft solders have been a modern method of repair, with its historical use as the original joining technique demonstrating its general durability and effectiveness. Optical microscopy, portable X-ray fluorescence, and micro-Raman spectroscopy were used to identify the soldering treatment, the chemical composition of the alloy, and the corrosion products. Investigation techniques showed the use of a modern tin-lead alloy as soft soldering in past interventions to treat cracks and fill losses. Cracks propagated due to soil pressures and ongoing corrosion processes, as well as the combined action of tensile forces and the surface-active molten solder. The ancient solder used to attach the dog and Eros to the lamp was a hard solder. The three pieces were made of high-leaded tin bronze, with Pb contents ranging from 10.5 to 13 wt%. The chloride and sulfate corrosion products detected by µ-RS were more aggressive in the object structure. The corrosion products of the soft solder consisted mostly of lead and tin oxides, basic carbonates, and sulfates.