Connector System Research Articles

Underwater Power Conversion and Junction Technology for Underwater Wireless Power Transfer Stations

Underwater wireless power transfer (UWPT) systems are appropriate for battery charging of compact, submerged devices without a complicated and expensive sealing structure or human contact because the power source and load are not physically connected. For the shore-based power supply situation, the underwater power conversion and junction technology should be required to drop down shore-based voltage to the target voltage for the underwater energy supply of the UWPT system. This paper proposes a lightweight, high efficiency and power density underwater power conversion connector system for the UWPT system, in which the LLC resonant converter is constructed with SiC transistors. The full load range zero-voltage switching (ZVS) and load adaptive characteristics have been achieved. The optimized RC level shift driver is adopted to highly reduce the switching loss of SiC transistors. Shore-based voltage of 1000 V was converted to the target voltage of 375 V for the UWPT system. The highest measured efficiency is over 98% at a load power level of 1500 W underwater conditions.

“A robust and simple catheter connector assembly for long-term self-administration experiments”

Intravenous self-administration in rats is used widely to study the reinforcing effects of drugs and serves as the gold standard for assessing their use and misuse potential. One challenge that researchers often encounter when scaling up experiments is balancing the cost, time investment to construct, and robustness of each implanted catheter. These catheters include multiple components such as surgical meshing and a variety of entry ports designed to facilitate the connection of the rat to a catheter port tethering system. Other considerations include maintaining the catheters free of blockage during the extent of the drug self-administration experiment. These large-scale studies provide ample opportunity for the catheter system to fail. The failure and replacement of commercially purchased catheters leads to ballooning expenses, and the failure of in-lab manufactured catheters requires the manufacture of reserves, also increasing costs, as these handmade products are inherently more variable. We have developed a catheter system that combines a commercially available implantable back-mounted entry connector system with inexpensive medical items such as surgical mesh, sutures, and an air-tight back flow prevention system to bolster the overall success of self-administration experiments.•Method to bolster commercially available jugular catheter components for long-lasting self-administration experiments.•Reduces the overall cost per unit of self-administration experiments.•Easily assembled by laboratory students and staff.

The Reliability Investigation on ACSR Splice Connector Systems Used in Overhead Power Transmission Lines

Due to material discontinuity and inherited forming mechanism from a crimped-type splice connector, the associated conductor-connector system is highly sensitive to system components aging, especially during high-temperature operations. Furthermore, due to the increase in power demand and limited investment in new infrastructure, existing overhead power transmission lines often need to operate at temperatures higher than the original designed values. This has led to the accelerated aging and degradation of conductor-connector systems. The implications of connector aging are two-fold: (1) significant increase in resistivity of the splice connector and (2) significant reduction in the connector clamping strength. Therefore, splice connectors are one of the weakest links in the electric power transmission infrastructure. In this paper we will discuss the reliability of splice connector systems, including both single stage and two stage splice connectors, used in ACSR conductor of transmission lines under high temperature operations.

Design of a Three-Phase Grid Connector System Using Power Transfer from Park’s Transformation

Design of a Three-Phase Grid Connector System Using Power Transfer from Park’s Transformation

Tri-axial shaking table testing of lighting support systems with pulley friction dampers and integrated dummy masses

Investigating pulley wireway systems equipped with friction dampers as alternatives to traditional exposed raceway light fixtures, this study adheres to the ICC-ES AC156 standard and evaluates the impact of system mass and connector types on seismic behavior using shaking table tests. The key findings indicate that an increased system mass variably affects the fundamental frequency of the system, depending on the type of connectors. In terms of earthquake performance, direct connectors outperformed pole connectors in the original system configuration, and the addition of dummy masses significantly reduced seismic energy while stabilizing acceleration responses in pole connector systems. Moreover, the study underscores the critical importance of minimizing pole length in systems using pole connectors and adopting a lower mounting height in systems with direct connectors to improve seismic performance.

Design and Fabrication of In-House Nozzle System to Extrude Multi-Hydrogels for 3D Bioprinting Process

Abstract The field of 3D bioprinting is rapidly expanding as researchers strive to create functional tissues for medical and pharmaceutical purposes. The ability to print multiple materials, each containing various living cells, brings us closer to achieving tissue regeneration. Deliberately transitioning between different material types encapsulating distinct cells and extruding through a single outlet, can lead to the achievement of user-defined material distribution, which is still challenging. In a previous study, we designed a Y-shaped nozzle connector system that allowed for continuous deposition of multiple materials through a single outlet. This system was made of plastic and had a fixed switching angle, rendering it suitable for a single use. In this article, we present the updated version of our nozzle system, which includes a range of angles (30 deg, 45 deg, 60 deg, and 90 deg) between the two materials. Changing the angles helps us figure out how that affects the control of backflow and minimizes the overall material switching time in the nozzle. We used stainless steel as the fabrication material and recorded the overall material switching time, comparing the effects of the various angles. Our previously developed hybrid hydrogel, which comprised 4% alginate and 4% carboxymethyl cellulose (CMC), was used as a test material to flow through the nozzle system. The in-house fabricated nozzle connectors are reusable, sterile, and easy to clean, ensuring a smooth material transition and flow. Our proposition can offer to achieve user-defined material distribution across a given region with appropriate selection of rheology and printing process parameters.

Optimal Shear Strengthening of Severely Deficient RC Beam Using JFRP Laminate with Anchor

High-strength jute fibre-reinforced polymer (JFRP) laminates have recently been introduced to strengthen RC beams against shear. In contrast to synthetic-based composites, JFRP laminates would be more ductile, compatible with steel shear rebar and effective in reducing debonding due to their lower modulus of elasticity. The prime objective of this research was providing an optimal solution to strengthen a severely deficient RC beam against shear using an externally bonded JFRP laminate with anchor. Fabrication of the JFRP laminate was carried out with the maximum fibre content of 37.5% to obtain high tensile strength. Five full-scale RC beam specimens were cast. Shear strengthening was done by an externally bonded JFRP laminate with double connector, multiple connector and embedded-bar anchor systems. The dimensions of JFRP laminate were obtained based on proposed guidelines. Based on the experimental test, the average tensile strength of the fabricated JFRP laminate was found to be 162 MPa. Results also showed that the JFRP laminate with multiconnector anchor increased the maximum shear capacity of deficient RC beams by 89% and the beams had failed by the fracture of laminate. Beams strengthened with embedded-bar anchor had shown flexural ductile failure. Both beams failed after yielding of flexural bar. The proposed guidelines could be used for shear strengthening of severely deficient beams to enhance the maximum shear capacity using full strength of JFRP laminate with anchor. KEYWORDS: RC beam, Shear strengthening, JFRP laminate, Anchor, Optimal design

Monitoring the Condition of the 20 kV Switching Substation in the Tual Rayon Saumlaki Area

A 20 kV cubicle is a set of electrical equipment installed in a distribution substation as a distributor, circuit breaker, connector, controller, and protection system for the 20 kV voltage power distribution. The frequent issue in these cubicles is corona discharge on electrical equipment, which is a phenomenon occurring when the air around conductors or conductive materials becomes ionized, resulting in the release of charges that can lead to insulation failure in the equipment. The consequences are severe as it can damage the equipment inside the cubicle and cause power losses. This research analyzes the influence of humidity, temperature, sound, and light conditions inside the cubicle to identify the symptoms of corona discharge in the 20 kV cubicle and its accessories. The goal is to create a tool that can address and anticipate the issues related to corona discharge caused by the effects of humidity, temperature, sound, and light.

Experimental study on the compression-shear performance of a new-type circumferential joint of shield tunnel

To investigate the compression-shear behavior of a new circumferential joint based on the sleeve-straight bolt combination type connection of large-diameter shield tunnels, a series of full-scale joint experiments was carried out. In the process of the experiment, more attention was paid to the specimen displacement, bolt stress and joint damage mode. On the basis of these experiment phenomena, this study discussed the compression-shear bearing process of the new connector, analyzed the damage mode of the joint structure, and finally evaluated the performance of the new connector. It is found that the bearing process of the joint can be divided into four stages: the transitional stage for overcoming the friction of the concrete, the sleeve bearing stage for the sleeve bearing shear loads alone, the combined bearing stage for bearing shear loads by the connector system, and the structural damage stage for structural instability and damage. Generally speaking, affected by connector position and hand hole, the positive compression-shear stiffness of the joint is less than the negative compression-shear stiffness, and the positive shear strength of the joint is greater than the negative shear strength. The increase of longitudinal axial force will improve the compression-shear performance of the joint. The relationship between longitudinal axial force and joint stiffness is a logarithmic function. The use of new type of connector can effectively improve the compression-shear stiffness of joints under low shear loads, but the application of straight bolts will lose part of the strength performance.

Optimization of a temporary road traffic steel barrier using explicit finite element method and laboratory testing

Over a million people die in road crashes and tens of millions result injured or disabled each year, globally. Hence, there is a constant concern for improving the safety of the roads to protect road users, and those at the most risk, the road workers. Construction, maintenance, and utility work are constantly needed to ensure safety and functionality of roads and highways. Temporary road traffic barriers are used to separate passing traffic from the workspace and protect the workspace from an errant vehicle intrusion. Steel barriers are light, and their major advantage is rapid installation. These barriers are not anchored to the ground, and their behavior relies on the base-pavement friction, mass inertia, and stiffness of the system. The paper describes a methodology that was successfully applied for the development of a temporary road traffic steel barrier in compliance with the European specification EN 1317. The study included a simplified theoretical analysis of 178 barriers, static laboratory tests of three types of barrier connectors, development of explicit finite element models (EFEMs) of four selected barrier designs, and a full-scale crash test of the final barrier design. It is shown that static laboratory tests of complex connector systems can help to improve the design process and reduce the cost. The analysis and use of EFEMs was enough so that just a single full-scale crash test was sufficient for certification of the barrier design for use in Europe. The final barrier is compliant with the EN 1317–2 requirements for T1/W1 (TB21) containment level, which was confirmed by a full-scale crash test.

Modeling and Measuring of Relative Motion at Contact Point of Electrical Connector for the Prediction of Vibration-Induced Fretting Damage

The relative motion at the contact interface induced by engine vibration is one of the most significant causes for the fretting damage. However, at present, several vibration simulations models have been investigated in literature to predict fretting degradation. Unfortunately, those finite element (FE) models do not take into account all the connector components (more than 10) with the cable, the non-linear mechanical contact and the prestress state of different components after assembled process. This paper describes and illustrates the approaches used for a three-dimensional FE modeling and vibration simulation of electrical connector to evaluate the relative displacement between the terminals at contact point, and when the fretting occurs. A series of experimental tests were also conducted to validate the simulation. A sinusoidal vibration with a single frequency and amplitude were applied to the connector system. It was demonstrated that, test and simulation presented similar results. Finally, an approach for predicting connector risk of fretting damage is established by combining the contacts endurance and relative motion at contact point and eventually quantify the threshold amplitude of fretting.

Shear connector systems for composite beam with cold-formed steel of lipped C-channel section

Shear connector systems for composite beam with cold-formed steel of lipped C-channel section

Blast mitigation performance of a novel cladding–connector​ system

A novel cladding–connector system with excellent energy absorption capacity was proposed to protect vulnerable walls in frame structures subjected to blast load in the present study. The cladding–connector system was constructed by combining a sacrificial cladding consisting of an aluminum foam core sandwiched by two steel plates and four connectors made of corrugated steel tubes. On one hand, the cladding absorbed a considerable amount of blast energy. On the other hand, the connectors controlled the load transfer to the protected structure to certain specific pre-defined value. With this approach, both relatively high energy absorption and relatively low load transfer can be achieved simultaneously. Specifically, based on the quasi-static compression test on the connectors and the field blast test on the sacrificial cladding, the numerical model of the proposed system was established with ANSYS/LS-DYNA and validated with the test results. Then the deformation mode, energy dissipation, and load transfer of the cladding–connector systems with flexible or rigid connectors under various charge weights were numerically studied and compared. Results showed that the proposed cladding–connector​ systems could dissipate a considerable amount of energy under blast, in which the major part was dissipated by the cladding and the rest by the connectors. Particularly, compared to the cladding–connector system with rigid connectors, the cladding–connector system with flexible connectors exhibited superior performance in terms of energy absorption and load transfer, especially under intense blast. With the merits of excellent energy absorption, significant blast intensity reduction, and load shift from the vulnerable walls to the load-bearing components, the proposed cladding–connector system with flexible connectors was more promising to effectively protect the existing frame structures against blast.

Biomechanical comparison of different rod-to-rod connectors to a conventional titanium- and cobalt chromium posterior spinal fixation system

IntroductionSeveral types of rod-to-rod connectors are available for the extension of spinal fixation systems. However, scientific literature regarding the mechanical performance of different rod-to-rod connector systems is lacking. Research questionThe goal of this study was to evaluate the mechanical characteristics of axial and lateral rod connectors in comparison to a conventional pedicle screw rod (titanium and cobalt chromium) construct. Material and methodSix types of instrumentations were investigated in a standardized test model to quantify the mechanical differences: 1: titanium rod; 2: titanium rod with axial connector; 3: titanium rod with lateral connector; 4: cobalt chromium rod; 5: cobalt chromium rod with axial connector; 6: cobalt chromium rod with lateral connector. All groups were tested in static compression, static torsion and dynamic compression and statistically compared regarding failure load and stiffness. ResultsIn static compression loading, the use of connectors increased the construct stiffness, but unaffected the yield load. The use of a cobalt chromium rod significantly increased by approximately 40% the yield load and stiffness in comparison to the titanium rod configurations. Under dynamic compression, a similar or higher fatigue strength for all tested groups in comparison to the titanium rod configuration was evaluated, with the exception of titanium rod with axial connector. ConclusionBiomechanically, using rod connectors is a secure way for the extension of a construct and is mechanically equal to a conventional screw rod construct. However, in clinical use, attention should be paid regarding placement of the connectors at high loaded areas.

Shifting and Expanding Clause Combining Strategies in Heritage Turkish Varieties

Turkish is a language described as relying predominantly on non-finite subordination in the domain of clause combining. However, there are also strategies of finite subordination, as well as means of syndetic and asyndetic paratactic clause combining, especially in the informal settings. Clause combining is and has been one of the focal points of research on heritage Turkish (h-Turkish). One point is particularly clear: In comparison with the monolingual setting, finite means of clause combining are more frequent in h-Turkish in Germany, the U.S., and the Netherlands, while non-finite means of clause combining are less frequent. Overall, our results confirm the findings of earlier studies: heritage speakers in Germany and the U.S. prefer paratactic means of clause combining using connectors, as opposed to monolingual speakers. Our results also reveal that age (adolescents vs. adults) and register (informal vs. formal) significantly modulate the use of connectors. Moreover, we find that the shift in preferences in means of clause combining triggers an expansion in the system of connectors and leads to the development of new narrative connectors, such as o zaman and derken. The system of syndetic paratactic clause combining is expanding in heritage Turkish. This expansion calls for multifaceted modeling of change in heritage languages, which integrates language-internal factors (register), dynamics of convergence with the contact languages, and extra-linguistic factors (age and language use).

A Magnetosome-Based Platform for Flow Biocatalysis.

Biocatalysis in flow reactor systems is of increasing importance for the transformation of the chemical industry. However, the necessary immobilization of biocatalysts remains a challenge. We here demonstrate that biogenic magnetic nanoparticles, so-called magnetosomes, represent an attractive alternative for the development of nanoscale particle formulations to enable high and stable conversion rates in biocatalytic flow processes. In addition to their intriguing material characteristics, such as high crystallinity, stable magnetic moments, and narrow particle size distribution, magnetosomes offer the unbeatable advantage over chemically synthesized nanoparticles that foreign protein “cargo” can be immobilized on the enveloping membrane via genetic engineering and thus, stably presented on the particle surface. To exploit these advantages, we develop a modular connector system in which abundant magnetosome membrane anchors are genetically fused with SpyCatcher coupling groups, allowing efficient covalent coupling with complementary SpyTag-functionalized proteins. The versatility of this approach is demonstrated by immobilizing a dimeric phenolic acid decarboxylase to SpyCatcher magnetosomes. The functionalized magnetosomes outperform similarly functionalized commercial particles by exhibiting stable substrate conversion during a 60 h period, with an average space–time yield of 49.2 mmol L–1 h–1. Overall, our results demonstrate that SpyCatcher magnetosomes significantly expand the genetic toolbox for particle surface functionalization and increase their application potential as nano-biocatalysts.

Multi-objective optimization of cross laminated timber-concrete composite floor using NSGA-II

Cross-laminated timber (CLT) is an engineered wood product made of multiple glued layers in the form of a panel suitable for flooring systems. CLT can also be mechanically connected to the concrete layer using the connector systems to create a CLT-concrete composite (CCC). This concept enhanced the structural performance of the floor and could be adopted for mid-and high-rise buildings. However, the design of the CCC floor involves the optimization of multiple structural and non-structural elements. In this study, we tackle the gap in the literature by carrying out a multi-objective optimization of the CCC floor with notched connectors by minimizing total thickness, total weight, and total material cost considering structural, vibration comfort, and especially, fire conditions constraints using the well-developed genetic algorithm (NSGA-II). The optimal solutions are presented in the Pareto fronts of multiple floor spans and cost ratio timber/concrete. The study also gives insight into the influence of design parameters and the governing design constraint. However, we only focus on one type of floor (CCC) and do not implement the environmental aspect of the structure.

Solving the problem of IV dislodgement.

Most patients in hospital will have some form of intravenous (IV) catheter in situ at some time to facilitate the administration of IV therapy. Accidental dislodgement, although widespread, is often unrecognised as a contributor to IV catheter failure. Dislodgement usually contributes to the delay in the administration of treatment, time-consuming IV restarts and a potential need for more invasive procedures. Dislodgement has serious implications, with costs to both patient and healthcare costs. Historically, prevention of IV catheter dislodgement has focused on the use of the correct securement methods and technique; however, these fail in many occasions, for example, where patients are confused or during bed transfers. In the recent years, new breakaway connector systems, such as ReLink, have been designed, which allow the tubing to become disconnected when undue pressure or pull is placed on it. This is done by a safety release valve that breaks apart, sealing off both ends of the tubing in an aseptic manner, while shutting off medication flow and preserving IV catheter integrity. Awareness raising and education focusing on accidental IV catheter dislodgement and the different ways to reduce its incidence in clinical practice would improve patient safety and potentially have significant healthcare savings.

Applications of continuum fatigue risk monitoring in riser connectors system integrity management

This paper discusses the effects of marine riser connectors (MRCs) on fatigue failure risk using multi-coupling models. When MRCs are subjected to vortex-induced fatigue, a risk early warning strategy is used for effective risk monitoring as a preventive measure for the operation of MRCs. To ensure safe marine oil and gas production and to improve fatigue failure prevention and control, research on offshore structural fatigue risk failure theory criteria and evaluation and the vibration fatigue characteristics of MRCs over time and frequency is characterized. By coupling data-driven technological means, including rain-flow counting (RFC), Hilbert–Huang transform (HHT), power spectral density (PSD), artificial neural network (ANN), risk-based inspection (RBI), and risk management measures (RMM) to assess the fatigue risk characteristics of in-service members in special offshore environments. The fluid-structure interaction characteristics of MRCs and a load spectrum are analysed by empirical mode decomposition (EMD) to determine the changes in the components of an intrinsic mode function (IMF) and investigate the degree of fatigue damage. The fatigue damage of MRCs is predicted using the PSD of the IMF and the RFC of the IMF-coupled ANN time series prediction model. The results show that using any IMF component or combined component data as input to the ANN and training set facilitates cross-validation of the analysis. When the input layer and a hidden layer of the ANN are optimized and properly trained, the predicted performance is suitable. Through early warnings and coordination, the spread of fatigue failure risk trends can be predicted, and warning information is issued accordingly.

Orthogonal protein decoration of DNA nanostructures based on SpyCatcher-SpyTag interaction.

We present an efficient and readily applicable strategy for the covalent ligation of proteins to DNA origami by using the SpyCatcher-SpyTag (SC-ST) connector system. This approach showed orthogonality with other covalent connectors and has been used exemplarily for the immobilization and study of stereoselective ketoreductases to gain insight into the spatial arrangement of enzymes on DNA nanostructures.