Search Results (18)

As maritime operations become increasingly reliant on interconnected information technology (IT) and operational technology (OT) systems, ensuring cybersecurity on vessels has become more critical than ever. One of these systems is the Integrated Navigation System (INS), which assists the Officer of Watch (OOW) on the bridge in ensuring safe navigation. The INS comprises several components that may be susceptible to cyber attacks, hence it faces cyber risks that need to be mitigated. Cyber risks are understood differently, depending on perspective. In this paper, we determine the perspective that the research community has of cyber risk, focusing on the INS, and that of professionals representing the maritime industry, and analyze similarities and differences. To this end, we conduct a systematic literature review and interviews with maritime professionals. This study provides useful insights for researchers and professionals seeking to understand the cyber risks of the INS. Full article

The food and agriculture sector is a cornerstone of critical infrastructure (CI), underpinning global food security, public health, and economic stability. However, the increasing digitalization and connectivity of operational technologies (OTs) in this sector expose it to significant cybersecurity risks. Blockchain technology (BT) has emerged as a transformative solution for addressing these challenges by enhancing network security, traceability, and system resilience. This study presents a comprehensive review of BT applications in OT security for food and agriculture CI, employing bibliometric and content analysis methods. A total of 124 relevant articles were identified from six databases, including the Web of Science Core Collection and MEDLINE^®. Bibliometric analysis was conducted across five dimensions: publication year, literature type, journal distribution, country contributions, and keyword trends. The findings are meticulously organized through tables, charts, and graphs. The year 2018 marked a surge in research within this domain, with the IEEE Internet of Things Journal and IEEE ACESS emerging as the most prolific journals, each boasting nine publications. The United States, China, and India are at the forefront in terms of journal citation counts. Our analysis determined that a reference count of 37 serves as an appropriate threshold. Otoum Safa stands out as the author with the highest number of published articles, totaling four. Keywords such as “blockchain”, “internet of things”, “smart contract”, “security”, and “critical infrastructure” appear with significant frequency. The statistics, trends, and insights gleaned from this bibliometric analysis can guide researchers in the OTCI field to forge a coherent and logical research trajectory. Content analysis further identified six key research areas within this domain: identity authentication and data verification, secure access control, attack detection and perception, data security and protection, data backup and recovery, and attack assessment and attribution. Based on these insights, a general framework is proposed to guide future research and practical applications of BT in securing OT within food and agriculture CI. This study systematically analyzes the current research landscape, challenges, and opportunities for BT in securing the OT critical to food and agriculture CI. By bridging the gap between blockchain innovations and the operational needs of the food and agriculture sector, this work contributes to advancing strategic implementation and improving the security of CI systems. Full article

The maritime industry’s increasing integration of IT/OT systems into vessel operations has significantly elevated its exposure to cyber–physical threats, making the development of effective cyber risk management strategies a necessity. This paper provides an outlook of the current landscape of cyber security threats and vulnerabilities for the maritime sector and vessels. An outline of the relevant governmental and industry directives, standards, and guidelines for cyber security in maritime vessels is given. Considering maritime vessels as critical elements of the maritime critical infrastructure sector, a number of relevant cyber–physical security assessment methods are presented. Bridging cyber–physical security, process safety, and security, API SRA (American Petroleum Institute Security Risk Analysis) and BTA (Bow-Tie Analysis) are presented as the most applicable cyber–physical security assessment methods for complex maritime vessels, such as an offshore oil and gas drillship. The scenario of a cyber-attack on the Dynamic Positioning (DP) system of a drillship is presented with the use of API SRA and BTA. The difficulties in the implementation of NIST CSF v2.0 and IACS UR E26 and UR E27 in the maritime sector are also discussed. The need for intensified research on and the formulation of bespoke cyber security measures to mitigate the evolving cyber threats within the maritime domain is highlighted. The need for the allocation of training and resources for the reinforcement of the capacity of a maritime vessel’s crew in the mitigation of cyber threats and safe maritime operations is emphasized. Full article

A reaction in anhydrous toluene between the formally unsaturated fragment [Ln(hfac)₃] (Ln³⁺ = Eu³⁺, Gd³⁺ and Er³⁺; Hhfac = hexafluoroacetylacetone) and [Al(qNO)₃] (HqNO = 8-hydroxyquinoline N-oxide), here prepared for the first time from [Al(O^tBu)₃] and HqNO, affords the dinuclear heterometallic compounds [Ln(hfac)₃Al(qNO)₃] (Ln³⁺ = Eu³⁺, Gd³⁺ and Er³⁺) in high yields. The molecular structures of these new compounds revealed a dinuclear species with three phenolic oxygen atoms bridging the two metal atoms. While the europium and gadolinium complexes show the coordination number (CN) 9 for the lanthanide centre, in the complex featuring the smaller erbium ion, only two oxygens bridge the two metal atoms for a resulting CN of 8. The reaction of [Eu(hfac)₃] with [Alq₃] (Hq = 8-hydroxyquinoline) in the same conditions yields a heterometallic product of composition [Eu(hfac)₃Alq₃]. A recrystallization attempt from hot heptane in air produced single crystals of two different morphologies and compositions: [Eu₂(hfac)₆Al₂q₄(OH)₂] and [Eu₂(hfac)₆(µ-Hq)₂]. The latter compound can be directly prepared from [Eu(hfac)₃] and Hq at room temperature. Quantum mechanical calculations confirm (i) the higher stability of [Eu(hfac)₃Al(qNO)₃] vs. the corresponding [Eu(hfac)₃Alq₃] and (ii) the preference of the Er complexes for the CN 8, justifying the different behaviour in terms of the Lewis acidity of the metal centre. Full article

Advanced reliability assessment can be required when evaluating existing bridge structures through proof load testing. The target load of a proof load test typically requires input from resistance models; however, bridges with a low documentation level are often the most relevant for proof load testing, and resistance models thus involve significant uncertainties. This paper presents a different approach to proof loading and target proof load, in which the resistance model is not included in the determination of this load. Instead, the target proof load is determined based on load models coupled to the desired target failure probability, thus ensuring sufficient safety of the existing bridge. The method is in line with the proposal for a new Eurocode on assessment of existing structures and is deemed to be superior to existing approaches. An essential assumption of the method is that monitoring systems can identify stop criteria before irreversible damage occurs. The approach was applied in a case study, where an OT-slab bridge with a span of 6.5 m was proof-load-tested and reclassified for capacity upgrading of a road stretch in Denmark. Full article

In full-arch implant rehabilitations, when the anterior screw abutment channel compromises the aesthetic of the patient, the OT-Bridge system used with its Seeger rings may provide the necessary retention of the prosthesis. However, no studies have evaluated the forces generated at the Seeger level during loading. This Finite Element Analysis aims to investigate the mechanical behavior of Seeger rings in a mandibular model with four implants and an OT-Bridge system, used without one or two anterior prosthetic screws. A 400 N unilateral load was virtually applied on a 7 mm distal cantilever. Two different variables were considered: the constraint conditions using two or three screws instead of four and the three different framework materials (fiberglass reinforced resin, cobalt-chrome, TiAl6V4). The FEA analysis exhibited tensile and compressive forces on the Seeger closest to the loading point. With the resin framework, a tension force on abutment 3.3 generates a displacement from 5 to 10 times greater than that respectively expressed in metal framework materials. In a full-arch rehabilitation with four implants, the case with three prosthetic screws seems to be a safer and more predictable configuration instead of two. Considering the stress value exhibited and the mechanical properties of the Seeger, the presence of only two prosthetic screws could lead to permanent deformation of the Seeger in the screwless abutment closest to the loading point. Full article

Nowadays, digital technologies have brought very important advancements in clinical prosthetic dentistry. However, a full digital workflow is still considered to be challenging in the management of full-arch implant cases with immediate prosthetic loading. The aim of this case report is to show a full-digital workflow for the fabrication of an implant-prosthetic fixed provisional prosthesis for immediate loading on seven implants in the upper maxilla. The static guided implant surgery and the OT Bridge prosthetic system were used to rehabilitate the patient. In this way, the combination of a well-known surgical technique with a peculiar prosthetic system that allows for a certain degree of tolerance resulted in it being useful for full-arch immediate loading. Future research and studies are necessary to prove the reliability of this full-digital protocol. Full article

Structural properties of the anionic surfactant dioctyl sodium sulfosuccinate (AOT or Aerosol-OT) adsorbed on the mica surface were investigated by molecular dynamics simulation, including the effect of surface loading in the presence of monovalent and divalent cations. The simulations confirmed recent neutron reflectivity experiments that revealed the binding of anionic surfactant to the negatively charged surface via adsorbed cations. At low loading, cylindrical micelles formed on the surface, with sulfate head groups bound to the surface by water molecules or adsorbed cations. Cation bridging was observed in the presence of weakly hydrating monovalent cations, while sulfate groups interacted with strongly hydrating divalent cations through water bridges. The adsorbed micelle structure was confirmed experimentally with cryogenic electronic microscopy, which revealed micelles approximately 2 nm in diameter at the basal surface. At higher AOT loading, the simulations reveal adsorbed bilayers with similar surface binding mechanisms. Adsorbed micelles were slightly thicker (2.2–3.0 nm) than the corresponding bilayers (2.0–2.4 nm). Upon heating the low loading systems from 300 K to 350 K, the adsorbed micelles transformed to a more planar configuration resembling bilayers. The driving force for this transition is an increase in the number of sulfate head groups interacting directly with adsorbed cations. Full article

The aim of this study was to evaluate the stability of prosthetic screws after applying cyclic loadings in an “all-on-four” rehabilitation model with the OT Bridge system. The model was tested both with and without anterior screws. Four implant analogues following the “all-on-four” concept were inserted in an edentulous mandibular resin model. An OT Bridge system with a Cr–Co prosthetic framework was fabricated. Depending on the presence or absence of one or two anterior screws on the implant analogues, three groups were created, i.e., Gr.1: three tightening screws, Gr.2: two tightening screws, Control Group: four tightening screws. Each single group underwent subsequent 400,000 cyclic loads, simulating approximately a year of chewing by using a dynamometer machine. This cycle was repeated five times for each group, and preload loss values were evaluated on each prosthetic screw after each cycle. All the data obtained were analyzed by one-way ANOVA and Student’s t-test. No statistically significant differences after intragroup analysis were found. A statistically significant difference within the Gr.1 between the screws in positions 33 and 36, equal to 15.2% (p-value = 0.0176), was found. The OT Bridge seems a useful system to maintain the retention of a prosthesis during mechanical stress conditions even in the absence of one screw in an “all-on-four” rehabilitation. This could represent a good solution to solve the esthetic problem of the screw buccal access hole for fixed solutions. Full article

We present a quantum chemical analysis of the ¹⁸F-fluorination of 1,3-ditosylpropane, promoted by a quaternary ammonium salt (tri-(tert-butanol)-methylammonium iodide (TBMA-I) with moderate to good radiochemical yields (RCYs), experimentally observed by Shinde et al. We obtained the mechanism of the S_N2 process, focusing on the role of the –OH functional groups facilitating the reactions. We found that the counter-cation TBMA⁺ acts as a bifunctional promoter: the –OH groups function as a bidentate ‘anchor’ bridging the nucleophile [¹⁸F]F⁻ and the –OTs leaving group or the third –OH. These electrostatic interactions cooperate for the formation of the transition states of a very compact configuration for facile S_N2 ¹⁸F-fluorination. Full article

In proof-loading of concrete slab bridges, advanced monitoring methods are required for identification of stop criteria. In this study, Two-Dimensional Digital Image Correlation (2D DIC) is investigated as one of the governing measurement methods for crack detection and evaluation. The investigations are deemed to provide valuable information about DIC capabilities under different environmental conditions and to evaluate the capabilities in relation to stop criterion verifications. Three Overturned T-beam (OT) Reinforced Concrete (RC) slabs are used for the assessment. Of these, two are in situ strips (0.55 × 3.6 × 9.0 m) cut from a full-scale OT-slab bridge with a span of 9 m and one is a downscaled slab tested under laboratory conditions (0.37 × 1.7 × 8.4 m). The 2D DIC results includes full-field plots, investigation of the time of crack detection and monitoring of crack widths. Grey-level transformation was used for the in situ tests to ensure sufficient readability and results comparable to the laboratory test. Crack initiation for the laboratory test (with speckle pattern) and in situ tests (plain concrete surface) were detected at intervals of approximately 0.1 mm to 0.3 mm and 0.2 mm to 0.3 mm, respectively. Consequently, the paper evaluates a more qualitative approach to DIC test results, where crack indications and crack detection can be used as a stop criterion. It was furthermore identified that crack initiation was reached at high load levels, implying the importance of a target load. Full article

Industrial IoT (IIoT) is a novel concept of a fully connected, transparent, automated, and intelligent factory setup improving manufacturing processes and efficiency. To achieve this, existing hierarchical models must transition to a fully connected vertical model. Since IIoT is a novel approach, the environment is susceptible to cyber threat vectors, standardization, and interoperability issues, bridging the gaps at the IT/OT ICS (industrial control systems) level. IIoT M2M communication relies on new communication models (5G, TSN ethernet, self-driving networks, etc.) and technologies which require challenging approaches to achieve the desired levels of data security. Currently there are no methods to assess the vulnerabilities/risk impact which may be exploited by malicious actors through system gaps left due to improper implementation of security standards. The authors are currently working on an Industry 4.0 cybersecurity project and the insights provided in this paper are derived from the project. This research enables an understanding of converged/hybrid cybersecurity standards, reviews the best practices, and provides a roadmap for identifying, aligning, mapping, converging, and implementing the right cybersecurity standards and strategies for securing M2M communications in the IIoT. Full article

Edentulism is one of the most significant problems given the increase in the elderly population. The aim of the present investigation is to evaluate a case report with angled screwdriver solutions and new kinds of low-profile attachments in full arch rehabilitation with divergent implants. In this clinical case we will analyze how low-profile abutments with angled screwdriver channel in the OT Bridge system (Rhein83, Bologna, Italy) can be a predictable solution over time to create a fixed prosthesis on disparallel implants with a digital structure (New Ancorvis, Bologna, Italy) for the satisfaction of the patient and of the work team. Full article

Background: To compare the loss of preload in absence of loading and after a fixed number of cyclic loadings on 7-mm distal cantilever in two different connection systems using all-on-four prosthetic model. Methods: Two equal models of an edentulous mandible rehabilitated with all-on-four technique with two types of abutment system (MUA and OT-Bridge) supporting a hybrid prosthesis, were used. Initial torque values of the prosthetic fixing screw, after ten minutes from initial screw tightening and after 400,000 repeated loadings were registered using a mechanical torque gauge. Differences between initial and final torque values were reported for each anchoring system and the two systems were finally compared. Results: No statistically significant differences regarding the loss of preload between MUA and OT-Bridge system were found after 400,000 cyclic loadings; however, in MUA system it was found between anterior and posterior implant screws. A significant difference in preload loss was found only for MUA system comparing the initial screw torque to that measured after 10 min from the tightening in absence of cyclic loadings. Conclusions: Within the limits of the present study, MUA and OT-Bridge may be considered reliable prosthetic anchoring systems able to tolerate repeated cyclic occlusal loads on distal cantilever in all-on-four rehabilitation model without any significant loss of preload in screw tightening. Full article

Purpose: To evaluate preliminary data on survival and success rates of immediately loaded, screw-retained, restorations delivered on lower arches using narrow and low-profile OT Equator abutments. Methods: This retrospective study analyzed data of patients rehabilitated with OT Bridge (fixed prosthetic system built on OT Equator) prosthetic concept from November 2017 to February 2019 in five different centers. Outcome measures were implant and prosthetic survival rates, biological and technical complications, marginal bone loss (MBL), oral health impact profile (OHIP), bleeding on probing, and plaque index. Results: A total of 60 implants were inserted in 12 patients. Patients were followed for a mean period of 15.8 months (range 12–24). All the patients received OT Equator as intermediate abutments. Four out of 60 implants were connected to the prosthetic framework using only the Seeger system, without a screw. One year after loading, three implants failed (implant survival rate of 95.0%) in two patients. No prosthesis failed and no major biological and technical complications were experienced. One year after initial loading, the marginal bone level was 0.32 ± 0.2 mm. The OHIP before treatment was 87.7 ± 6.0. One year after treatment, OHIP was 23.6 ± 1.2. The difference was statistically significant (64.1 ± 7.2; p = 0.0000). One year after loading, 8.9% of the examined implant sites present positive bleeding on probing, while 5.8% of the implant sites presented plaque. Conclusions: The OT Equator abutments showed successful results when used to support mandible fixed dental prosthesis delivered on 4–6 implants. Whole prosthetic survival and success rates, high patient satisfaction, and good biological parameters were experienced one year after function. Further prospective studies are needed to confirm these preliminary results. Full article