Anchorage System Research Articles

Extraction of four premolars in hyperdivergent individuals, does it help? -A case report

Treatment of any malocclusion requires careful diagnosis and treatment planning to resolve aesthetic, occlusal, and functional problems. Premolar extractions in orthodontics, over the years has been carried out to relieve dental crowding and affect incisor inclination. Clinicians’ decisions on premolar extractions and the extraction patterns have been influenced by desired anchorage control or changes to the vertical dimension. The introduction of mini-screw skeletal anchorage systems has broadened our horizons by giving us complete control over the anchorage as well as good vertical control. However, this case report shows the vertical control and the anchorage achieved using the low-lying transpalatal arch. The use of basic armamentarium along with avoiding an invasive procedure, provides an equally efficacious treatment outcome.

Numerical Investigation of a Floating-Type Support Structure (Tri-Star Floater) for 9.5 MW Wind Turbine Generators

A numerical investigation of floating-type substructures for wind turbine generators was conducted by using time-domain simulation. A Tri-Star floater for 8–10 MW generators, which was developed by Samsung Heavy Industries (SHI), was chosen as the floating substructure. To make the anchor system, catenary mooring lines, considering redundancy, were installed on the floater. The main sources of external force on the wind turbine generator are wind, waves, and currents. To consider severe environmental conditions, Design Load Cases (DLCs) 1.6 and 6.1 of the IEC guidelines (IEC 61400-3-1) were chosen. From the measured environmental data for the installation site, the main parameters for the simulation conditions were obtained. The tilt angle and horizontal movement of the floater and the mooring tension for the different mooring systems were checked. The response of the floater during the failure of the mooring was also studied, and the critical failure of the mooring was confirmed. During the failure of the mooring, the redundancy system worked well, in which the movement of the floater was constrained within the criteria for all scenarios.

Numerical investigation into RC slabs strengthened using FRP and hybrid anchors

It is well understood that reinforced concrete (RC) members strengthened using fiber reinforced polymers (FRP) are limited by premature debonding which results in significant underutilisation of the FRP tensile strength. In order to mitigate this mode of failure, different types of anchorage systems have been developed and of these, hybrid anchors have shown significant success in shifting the mode of failure from premature debonding to FRP rupture. However, experimental data on hybrid anchors in flexural strengthening applications has been limited to date and insufficient data is currently available for development of anchor specification guidelines. This paper aims to generate additional data by developing and validating 3D finite element (FE) models to investigate the effect of hybrid anchors on RC slabs strengthened with FRP sheets. After successful validation of the model, parametric studies were conducted by varying concrete strength between 25 and 65 MPa in order to generate the required data. Lastly, two models are proposed which can be used to calculate the maximum FRP design strain when using hybrid anchors in FRP strengthened RC slabs subjected to flexural actions.

Attaching organic fibers to mineral: The case of the avian eggshell

Bird eggs possess a mineralized eggshell with a soft underlying fibrous membrane. These dissimilar material layers successfully evolved a structural attachment to each other as a conserved avian reproduction strategy essential to avian embryonic development, growth, and hatching of the chick. To understand how organic membrane fibers attach to shell mineral (calcite), 3D multiscale imaging including X-ray and electron tomography coupled with deep learning-based feature segmentation was used to show how membrane fibers are organized and anchored into shell mineral. Whole fibers embed into mineral across the microscale, while fine mineral projections (granules/spikes) insert into fiber surfaces at the nanoscale, all of which provides considerable surface area and multiscale anchorage at the organic-inorganic interface between the fibrous membrane and the shell. Such a reciprocal anchorage system occurring at two different length scales between organic fibers and inorganic mineral provides a secure attachment mechanism for avian eggshell integrity across two dissimilar materials.

Experimental Investigation on the Anchorage Performance of a Tension–Compression-Dispersed Composite Anti-Floating Anchor

Rapid advancements in construction technologies have accelerated the development of complex and deep underground structures, raising concerns about the impact of groundwater on structures, particularly anti-floating measures. Traditional tensioned anchors, commonly used for preventing flotation, suffer from limitations like low pull-out bearing capacity, shallow critical anchoring depth, and localized stress concentration. To overcome these limitations, this paper introduces a tension–compression dispersed composite anchor, which combines casing, load-bearing plates, and tensioned anchors. Comparative tests were conducted between these composite anchors and traditional tensioned anchors to analyze their anchoring behavior. Our results show that tensioned anchors exhibit a stable axial force distribution as anchoring length increases. By identifying abrupt changes in the axial force curve, optimal anchoring lengths for load-dispersed anchors can be determined, thereby enhancing rock and soil strength utilization. The tension–compression-dispersed composite anchor outperforms tensioned anchors, with 1.44 times the ultimate bearing capacity for equivalent anchoring lengths and 1.1 times the capacity for an additional 1 m length. It also displays superior deformation adaptability and structural ductility under high-bearing loads compared to tensioned anchors with extended anchoring lengths. Effectively mobilizing the strength of the lower anchoring segment within the rock and soil results in a lower critical anchoring depth and a more uniform distribution of lateral friction resistance. In conclusion, the tension–compression-dispersed composite anchor offers significant advantages, making it a promising engineering solution for anti-floating anchor systems in complex underground environments.

A novel winding–wedge anchorage for CFRP straps: Conceptual design and performance evaluation

Carbon fibre-reinforced polymer (CFRP) straps can be utilised as tension members in structures on account of their high-strength properties. The development of an effective anchorage device for CFRP straps that can fully utilise the strength of straps before anchorage failure is an ongoing technical challenge. To address such knowledge gap, a novel anchorage device termed winding-wedge anchorage that combines winding and wedge anchorage mechanisms is reported herein. For the winding anchorage component, different numbers of winding turns are applied. For the wedge anchorage component, three different types of wedge anchorage systems are investigated namely bonding, friction clamping, and friction non-clamping. Initially, the working mechanism, theoretical winding–wedge anchorage model (herein theoretical model), and design parameters are determined. Experimental and finite element analyses are then reported to assess the behaviour of the anchorage including failure modes and anchorage efficiencies. The accuracy of the theoretical model is also reported. It is concluded that the efficiency of the anchorage device is primarily dependent on the wedge anchorage component. Moreover, the bonding wedge anchorage component performed better than the other two wedge anchorage systems. The theoretical model and experimental results revealed that 1.5 winding turns results in an optimal interaction between the winding and wedge anchorages components.

Measuring Received Signal Strength of UWB Chaotic Radio Pulses for Ranging and Positioning

The use of ultra-wideband (UWB) signals for local positioning is very attractive for practice, because such signals have the potential to provide centimeter precision. In this paper, we consider wireless ranging (distance measurement) and positioning, using one of the kinds of UWB signals, i.e., chaotic radio pulses, which are noise-like signals with no constant shape. The distance measurement is based on an assessment in the receiver of the power of UWB chaotic radio pulses emitted by the transmitter. A new method for estimating their power and its experimental implementation is proposed and described. Experimental layouts of the transmitter and receiver and the principles of their operation are described. To determine the main features of this method under real signal propagation conditions, full-scale indoor measurements were carried out, and statistical estimates of the accuracy were made. We present the results of experimental testing of the proposed approach for positioning the emitter relative to a system of anchors in an office space 6 × 6.5 m2 in the mode of measuring object coordinates on a line and on a plane. The mean absolute error (MAE) of distance measurement (1D) was 25 cm, and the root mean squared error (RMSE) was 39 cm. When positioning on a plane (2D), the MAE of coordinate estimation was 34 cm and the RMSE was 42 cm. The proposed distance measurement method is intended for use in wireless UWB transceivers used in wireless sensor networks.

Eco-Design and Additive Manufacturing of an Innovative Double-Casing Pedometer for Oestrus Detection in Dairy Cow

The analysis of motor activity has been revealed to be essential for monitoring dairy cows’ behavior, with the main aim of identifying the onset of oestrus in time. Pedometers used for oestrus detection have a current average working life on the market of about 5 years. At the end of that period, devices are disposed of, posing a relevant question regarding environmental sustainability. The present work proposed a method to achieve an eco-design of pedometers compliant with the guidelines of the Green Deal. Specifically, a new thermo-plastic organic compound made of polyamide 66 reinforced with organic hemp fibers (trade name SDS Nylon) was adopted. The feasibility, benefits, and performance of this material were assessed with a major emphasis on strength, lightweight, and surface finish. The material in addition to ensuring adequate chemical and mechanical resistance is biocompatible and recyclable. It assures better animal welfare and reduces both environmental impacts and management costs for farmers. Other innovations introduced in this study consisted of the adoption of a double casing. An external case was conceived with a protective function of the measurement system and fixed to a cow’s foreleg by an easy anchor system. An internal case was specifically designed to house the electronic components and to be moved from one cow to another after the pregnancy diagnosis. The solutions proposed in this research will contribute to guaranteeing pedometers a longer lifetime and better recyclability than existing commercial ones, consequently limiting the environmental load derived from their disposal.

Effective prediction finite element model of pull-out capacity for cast-in-place anchor in high strain rate effects

Cast-in-place anchors are being increasingly used in many applications including building construction, bridge, and power plants. The anchorage to concrete systems are subjected to tensile, shear and combined loads from a variety of loading circumstances including static, dynamic, and shock loading. Despite extensive studies on these systems, reliable numerical models for predicting the behavior of these anchors are still limited. Therefore, this paper investigated the tensile behavior of cast-in-place anchorage to concrete systems, to propose an effective model for reproducing anchorage behavior using finite element (FE) methods. Experiments and code-based models for the anchorage system in tension were used to evaluate the numerical models for cast-in-place anchors in concrete, and the most suitable model, with advantages in accuracy and saving analysis time, was chosen. Finally, the FE model was used to study the tensile capacity and related dynamic increase factor for various strain rates, anchor diameters, and embedment depths.

Patent bibliometrics in spinal deformity: the first bibliometric analysis of spinal deformity's technological literature.

Bibliometric analyses have gained popularity for studying scientific literature, but their application to evaluate technological literature (patents) remains unexplored. We conducted a bibliometric analysis on the top 100 most-cited patents in scoliosis surgery. Multiple databases were queried using The Lens to identify the top 100 scoliosis surgery patents, which were selected based on forward patent citations. These patents were then categorized into 8 groups based on technological descriptors and assessed based on various factors including earliest priority date, year issued, and expiration status. The top 100 most-cited patents included technology underlying anterolateral tethering and distraction systems (n = 11), posterior tethering and distraction systems (n = 23), posterior segmental bone anchor and rod engagement systems (n = 29), interbody devices (n = 10), biological and electrophysiological agents for scoliosis treatment and/or improved arthrodesis (n = 8), intraoperative arthroplasty devices (n = 5), orthotic devices (n = 12), and implantable devices for non-invasive, postoperative alterations of skeletal alignment (n = 2). Seventy-five patents were expired, 21 are still active, and 4 were listed as inactive. The late 1970s and early 2000s saw increased numbers of patent filings. Demonstrated trends showed no meaningful correlation between patent rank and earliest priority date (linear trendline y = 0.2648x - 477.27; R2 = 0.0114), while a very strong correlation was found between patent rank and citations per year (power trendline y = 118.82x--0.83; R2 = 0.8983). Patent bibliometric analyses in the field of spinal deformity surgery provide a means to assess past advancements, better understand what it takes to make a difference in the field, and to potentially facilitate the development of innovative technologies in the future. The method described is a reliable and reproducible technique for evaluating technological literature in our field.

Temporary anchorage devices-steering the treatment of borderline orthognathic case to an orthodontic approach

Orthodontics as a specialty deals with various skeletal and dental malrelations. But, the extent to which the case can be treated with a pure orthodontic approach with the use of fixed appliances was limited. With the advent of temporary anchorage devices, our horizons have broadened and these “WONDER SCREWS” have allowed us to tackle more complicated cases while avoiding surgeries. The skeletal anchorage system has revolutionized the way we address different malocclusions. This case report is aimed at showcasing the successful management of the spaces required to improve the esthetics and function of an adult male through the simultaneous retraction and intrusion of the whole anterior segment. 2 The treatment objectives were achieved through the retraction of the maxillary anteriors using TADs as anchorage and intrusion using the TADs.

Repair, flexural upgrading and seismic retrofit of RC columns with reinforced FRCC light jacket

An innovative repair, flexural upgrading and seismic retrofit solution consisting of a reinforced light jacket (i.e., 3–4 cm) made of Fibre Reinforced Cement Composites, FRCC coupled with a High-Performance steel reinforcement is proposed for existing reinforced concrete (RC) columns. The proposed solution consists in a FRCC light jacketing coupled with a High-Performance steel reinforcement that works both as anchorage system for the jacket and as additional transverse reinforcement (Reinforced FRCC light jacketing or RFRCC). The goal of the solution is to improve the columns resistance against the migration of aggressive agents and at the same time to increase its flexural capacity. The potential of the proposed solution is demonstrated on 6 full-scale RC columns experimentally tested under quasi-static cyclic loading. The RC columns under investigation are subjected to a seismic pre-damage before the application of the RFRCC jacket. Square and rectangular columns with smooth and deformed rebars are tested to assess the feasibility of the technique for the repair and flexural strengthening of existing deficient RC columns. The experimental results attest the high potential of the proposed technique in recovering and enhancing the flexural capacity, ductility and energy dissipation of seismically pre-damaged RC columns.

Numerical Simulation of Corrugated Steel Concrete Prefabricated Support Structure for Underground Engineering

The spray anchor system is commonly used for primary support in underground projects due to its advantages such as fast closure of excavation surfaces, tight connection with the surrounding rock, and high early strength. However, this system has several drawbacks, such as severe pollution, poor working conditions, long construction periods, and high labor costs. In response to the concepts of green construction and prefabrication, this study proposes an innovative composite structure consisting of corrugated steel plates and concrete, namely, corrugated steel–concrete (CSC), which is a prefabricated support structure for underground engineering. The proposed system involves on-site corrugated steel plates and concrete, and the concrete is poured into the corrugated steel plates without using shotcrete. This approach mitigates pollution and improves working conditions. After the introduction to the novel structural system, elaborate Abaqus numerical models are developed to investigate the mechanical performance considering full elastoplastic response until failure. The steel–concrete interfacial connections, as a major factor in composite structures, are carefully studied and discussed based on the delicate interfacial contact model. The deformations, stress distributions, and failure types are analyzed. A parametric analysis is also conducted to expand the efficient range. Theoretical analysis is further carried out, and design expressions are proposed, which are verified to be suitable for design considerations.

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

Effect of various factors related to the bond-type anchorage system on tensile performance of carbon fiber-reinforced polymer strand cables

Steel strands, which are most frequently used as internal/external tendons of prestressed concrete (PSC), are highly susceptible to corrosion, which degrades the structural stability of the PSC structures. Studies are underway to utilize carbon fiber-reinforced polymer (CFRP) strands in PSC structures as tendons to achieve structural performance comparable to that of existing steel strands, with the additional feature of corrosion resistance. However, such applications of CFRP strands require the accurate identification of the intrinsic properties of the material. This study conducted an analysis to establish a test method using bond-type anchorage that can evaluate the intrinsic properties of CFRP strands by setting several factors related to the bond-type anchorage system as variables. Tensile tests were conducted on the CFRP strands after fabricating the specimens according to the variables of the bond-type anchorage system (shape of the CFRP strand located inside the steel pipe and type of internal filler material). In addition, the compressive strength was measured to determine the mechanical properties of the cementitious filler materials. Based on the experimental results, the load-displacement curves, stress-strain curves, fracture shapes, and tensile strengths of various cases of CFRP strands were analyzed. The results of the study revealed that the split-strand CFRP fabricated with CP0.25 mixture as the bond-type anchorage system had the ability to fully obtained intrinsic tensile properties.

Awake intracerebroventricular delivery and safety assessment of oligonucleotides in a large animal model

Oligonucleotide therapeutics offer great promise in the treatment of previously untreatable neurodegenerative disorders; however, there are some challenges to overcome in pre-clinical studies. (1) They carry a well-established dose-related acute neurotoxicity at the time of administration. (2) Repeated administration into the cerebrospinal fluid may be required for long-term therapeutic effect. Modifying oligonucleotide formulation has been postulated to prevent acute toxicity, but a sensitive and quantitative way to track seizure activity in pre-clinical studies is lacking. The use of intracerebroventricular (i.c.v.) catheters offers a solution for repeated dosing; however, fixation techniques in large animal models are not standardized and are not reliable. Here we describe a novel surgical technique in a sheep model for i.c.v. delivery of neurotherapeutics based on the fixation of the i.c.v. catheter with a 3D-printed anchorage system composed of plastic and ceramic parts, compatible with magnetic resonance imaging, computed tomography, and electroencephalography (EEG). Our technique allowed tracking electrical brain activity in awake animals via EEG and video recording during and for the 24-h period after administration of a novel oligonucleotide in sheep. Its anchoring efficiency was demonstrated for at least 2months and will be tested for up to a year in ongoing studies.

Damage pattern recognition for corroded beams strengthened by CFRP anchorage system based on acoustic emission techniques

This study presents a damage pattern recognition approach for corroded steel beams strengthened by CFRP anchorage system based on acoustic emission clustering analysis. The proposed method includes four steps: acoustic emission signal acquisition, feature extraction, clustering analysis, and damage pattern recognition. Four corroded beams with different corrosion levels and strengthening schemes were tested under four-point bending loading. The acoustic emission signals were collected during the loading process and analyzed using Gaussian mixture model clustering method. The results showed that the collected AE data were analyzed using clustering analysis, successfully distinguishing the distinct damage patterns associated with each mode. The AE signals exhibited distinct characteristics for different damage modes: concrete matrix damage had high-frequency and low-energy characteristics, CFRP-matrix debonding showed intermediate values for all parameters, and CFRP tearing had longer durations, lower peak frequencies, and high-energy characteristics. Besides, the study identified three stages of the damage process: an initial stage with fewer low-intensity AE signals, a damage development stage characterized by an increase in concrete-matrix damage and CFRP – matrix debonding signals, and a continuous damage growth stage with significant AE signals associated with three damage modes. Furthermore, the degree of corrosion significantly influenced the cumulative AE energy of damage modes. Lower degrees of corrosion led to higher cumulative energy from concrete matrix damage and CFRP-matrix debonding. These findings provide valuable insights for understanding the damage evolution and failure mechanisms of CFRP-strengthened corroded beams. The use of AE techniques for damage pattern recognition can enhance the evaluation and design of CFRP anchorage systems, leading to more effective rehabilitation strategies for corroded structures.

A betaine-modified whole-cell biocatalyst with surface display of Thermomyces lanuginosus lipase for biodiesel production from Jatropha curcas oil

Yeast surface displaying lipases are promising biocatalysts for biodiesel synthesis. Thermomyces lanuginosus lipase (TLL) was displayed on Pichia pastoris cell surface by screening proper anchor system, resulting in a whole-cell biocatalyst (termed D-TLL). The lipase activity of D-TLL is the highest activity to date for surface-displayed TLL, reaching 2274.7 U/g dry cell weight (DCW). The obtained biocatalyst was efficient in converting Jatropha curcas oil into biodiesel. The biodiesel yield peaked 92.6% after 12 h adopting only 3.3% (w/w) of D-TLL in the solvent-free system. As compared to free TLL, the whole-cell biocatalyst showed a dramatic reduction of 48 h in reaction time. The further treatment with betaine enabled enhanced thermostability, hydrophobicity and methanol tolerance of biocatalyst (named D-TLL-betaine), and thereby increasing the reusability of the whole-cell biocatalyst. These results exhibited that the new biocatalyst, D-TLL-betaine, has great potential for biodiesel production.

The Effects of the volume Liquidity Shocks and Inflationary Environment on the Exchange Rate System’s Survival in countries with Exchange Rate Anchor and Inflation Targeting Monetary systems

The Effects of the volume Liquidity Shocks and Inflationary Environment on the Exchange Rate System’s Survival in countries with Exchange Rate Anchor and Inflation Targeting Monetary systems

Effect of wing plate structure on uplift resistance capacity of marine aquaculture anchor piles

As the main component of the anchorage system in marine aquaculture facilities, the anchor pile is key to ensuring safety and stability. However, conventional monopiles have limited capacity to withstand uplift forces, thus rendering them susceptible to deviations and potentially causing damage to facility structures. Hence, a new winged monopile is proposed to improve and optimize the anchor pile. In this study, laboratory experiments are conducted to investigate the effect of load inclination angle (θ = 0°, 30°, 45°, and 60°), wing length (L = 30, 50, and 70 mm), and wing width (W = 10, and 20 mm) on the uplift resistance capacity of anchor piles in silty clay. The results show that: the winged monopile exhibits at least a 15% improvement in uplift performance compared with the conventional monopile (without wings) when the smallest wing plate parameters are selected (W = 10 mm, L = 30 mm). Additionally, the effect of the wing width on the uplift resistance under an oblique load is more evident than that of the wing plate length. As the area of the wing plate increases, the range of improved wing plate efficiency first increases, and then gradually decreases. This study can be used as a reference for the design optimization of uplift piles and the construction of marine aquaculture.