Load Resistance Research Articles

Influence of Polymer Fibre Reinforcement on Concrete Anchor Breakout Failure Capacity.

With the increasing use of fibre-reinforced concrete, e.g., in industrial floor and tunnel construction, the associated fastening technology in this material has increasingly become the focus of scientific attention in recent years. Over 25 years ago, design and assessment guidelines for anchoring systems in reinforced concrete were established, which have since evolved into comprehensive regulatory standards. However, these standards only address plain and rebar-reinforced concrete as anchoring bases, neglecting fibre-reinforced concrete. The design of anchorage systems in fibre-reinforced concrete has not yet been standardised. Recent studies and product certifications accounting for steel fibre reinforcement are now seeing their way to publication, supported by a fair amount of scientific research studies. This paper aims to elucidate the effects of polymer fibre reinforcement in this application through a systematic investigation. Experimental studies were conducted to evaluate the system's load-bearing behaviour failing with concrete breakouts under tensile loading. By incorporating the determined material properties of polymer fibre-reinforced concrete and their mathematical interpretation, alternative model proposals are presented to assess concrete breakout resistance. The addition of polymer fibres significantly improves the load-bearing capacity and ductility of concrete under tensile loads, transforming its quasi-brittle response into a more ductile behaviour. Although the fibres had a minor impact on overall material strength, their influence on the tensile capacity of the anchors reveal a 15-20% increase in load resistance and up to a doubling of the failure displacements.

Biomimetic MOFs/GO membranes with enhanced charge density for osmotic power generation

Osmotic power generation is a renewable energy technology that harnesses energy from the natural mixing of freshwater and saltwater, offering a promising solution for sustainable energy. However, it is still a challenge to achieve high energy output without compromising scalability and stability. Herein, inspired by the nano-constrained dynamics of neuronal cell transmembrane transport, an anodic oxidation electrodeposition method is employed to fabricate metal organic frameworks (MOFs) within 2D graphene oxide (GO) layers. The in-situ integration of high-density charges within nanometer pore with 0.34 nm entrance of MOFs facilitates rapid and selective cation transport, which significantly increases the diffusion voltage (363.8 mV, 106 fold concentration gradient). Our device demonstrates a maximum output power of 6.82 μW under a 10 fold concentration gradient at a load resistance of 5000 Ω, possessing an energy conversion efficiency of 48.8% at an effective area of 12.56 mm2, which substantially surpasses the performance reported before. More importantly, the device performs exceptionally well, showing robust and stable performance. This is proven by its ability to power various electronic devices. These findings underscore the potential of biomimetic ion channel membranes in sustainable energy applications, offering a promising avenue for the broader field of energy harvesting technologies.

Respiratory Muscle Training in Para-Athletes: A Systematic Review on the Training Protocols and Effects on Reported Outcomes.

Respiratory muscle training (RMT) is considered an effective tool to improve cardiorespiratory limitations in athletes. The goals of this systematic review were to explore the role of RMT and its implementation within sport rehabilitation programs in para-athletes. Several databases were searched until January 2024. Eligible studies were independently reviewed by 2 reviewers. Quality assessment was made using the PEDro scale and version 2 of the Cochrane Risk-of-Bias Tool for Randomized Trials. Eight studies (a total of 108 participants) were selected for the analysis. Five studies preferred using resistive loading, while 2 studies used normocapnic hyperpnea, and 1 study used threshold inspiratory muscle training. Respiratory functions (respiratory muscle strength and endurance, spirometry measures) and exercise performance were assessed as the main outcomes. Significant increases in respiratory muscle strength were reported in 5 studies. Two studies observed improvement in respiratory muscle endurance and 3 studies reported increased exercise capacity. This review suggests that although RMT can enhance respiratory muscle strength and endurance, it should not be considered the primary method for boosting the exercise performance of para-athletes. Additional research is necessary to explore the impact of various RMT techniques on different outcomes from the perspective of sport rehabilitation in para-athletes.

A broadband bistable energy harvester with self-decreasing potential barrier effect: Design, modeling and experiments

The conventional bistable energy harvester (CBEH) is difficult to break through the potential barrier for large-amplitude inter-well motion under weak excitation environments, which results in a narrow effective bandwidth. This paper proposes a bistable energy harvester with self-decreasing potential barrier effect (BEH-DPBE) for harvesting low-frequency vibrational energy. A spring is introduced to transform the fixed end of the S-type power generating beam into a movable end, while its oscillator has a dual function of dynamically reducing the potential barrier in the return trip and enhancing the potential energy in the outward trip. The characteristics of the proposed energy harvester are evaluated and analyzed by combining finite element simulations, numerical studies, and experiments. Finally, the effects of key parameters, such as the spring pre-compression, proof mass, and load resistance, are studied. In low-frequency conditions, the effective bandwidth and peak-to-peak voltage of BEH-DPBE are 6.35 Hz (5.98–12.33 Hz) and 10.1 V, respectively. The proposed BEH-DPBE can effectively capture energy in low-frequency ambient vibrations.

Thermal stability of TiN gate electrode for 4H-SiC MOSFETs and integrated circuits

In this research, the thermal stability of single-stage amplifiers based on a 4H-SiC MOSFET with a TiN gate electrode was investigated. The results show that after 100 h aging at 400 °C in N2 ambient, the amplifier maintained good performance with stable voltage gain. The thermal stability of the amplifier is attributed to the stability of Ni/Nb/4H-SiC source/drain ohmic contact, implanted load resistor, and MOS structure with the TiN gate electrode. The results obtained from the 4H-SiC MOS structure show that the interface trap density at the SiO2/SiC decreases during the aging process. While the gate leakage current of the capacitor based on the Al gate electrode increases, it remains stable in structures with TiN gate electrodes after 100 h aging. The results obtained in this study indicate that TiN is promising for the gate electrode of 4H-SiC MOSFETs for high-temperature applications.

Enhancing efficiency in capacitive power transfer: exploring gap distance and load robustness

In this paper, the capacitive power transfer (CPT) technology is used as an alternative to inductive power transfer (IPT). CPT relies on electric fields that are not sensitive to the presence of any metals, utilizes metal electrodes for power transfer, and is less bulky compared to IPT. The proposed CPT system utilizes a Class-E resonant inverter with a double-sided inductor-capacitor (LC) matching circuit which operates at an optimum load, with a duty cycle, D=0.5 to gain an output power, W and efficiency, η=84.6%. The proposed CPT system enhances the system’s efficiency as compared to the past research while preserving the zero-voltage switching (ZVS) condition within a wider load range from 50 Ω to 1,316 Ω. This paper also shows that the proposed CPT system is less sensitive to load and coupling variations. Finally, the rate of power dissipated at varied load resistances, has been derived successfully to determine the sensitivity level of the proposed CPT systems toward load variations. These equations are then validated by plotting the efficiency graphs based on load and coupling variations.

Environmentally friendly p-type CTS-based thin-film thermoelectric generator

Cu-based sulphides are promising materials for environmentally friendly Te-free thermoelectric generators (TEGs). Cu2SnS3 (CTS) stands out for its electronic properties, stemming from its conductive Cu–S networks, especially in fully disordered cubic structural form. While wet chemical techniques are the most utilized for CTS synthesis, they introduce organic contaminants that reduce electronic connectivity between grains, limiting their performance as in-plane thin-film TEGs. We present a new method to improve the electronic properties of CTS thin films for thermoelectric applications involving three-step dry route synthesis of ball milling, thermal evaporation, and sulfurization of Cu2–Sn metallic precursors. Via this method, charge carrier concentration increased significantly, as estimated by Hall effect analysis, which was attributed to the Cu-poor stoichiometry, also confirmed via energy-dispersive X-ray spectroscopy (EDXS). Microstructural analysis by scanning electron microscopy (SEM) revealed micrometre-sized grains composed of even smaller crystalline domains, which X-ray diffraction (XRD) showed to be ~ 50 nm in diameter. When compared with literature results, our procedure leads to a fourfold enhancement in the thermoelectric power factor (PF=S2σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$PF={S}^{2} \\sigma$$\\end{document}), determined through the Seebeck coefficient measurements (S\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$S$$\\end{document}) and electronic conductivity (σ) estimated by the van der Pauw technique. The CTS TEG has a power volume density of 2.3 μW K−1 cm−3, measured by a custom current–voltage–power (I–V–P) setup with varying load resistance. Results present a 100% increase in performance compared to ink-based techniques and were reproducible across three different batches. This strategy, improving the density of the CTS thin films, offers a new way to enhance Cu-based thin-film TEGs.

The Effect of Carbon Nanotubes and Carbon Microfibers on the Piezoresistive and Mechanical Properties of Mortar

Sustainability, safety and service life expansion in the construction sector have gained a lot of scientific and technological interest during the last few decades. In this direction, the synthesis and characterization of smart cementitious composites with tailored properties combining mechanical integrity and self-sensing capabilities have been in the spotlight for quite some time now. The key property for the determination of self-sensing behavior is the electrical resistivity and, more specifically, the determination of reversible changes in the electrical resistivity with applied stress, which is known as piezoresistivity. In this study, the mechanical and piezoresistive properties of mortars reinforced with carbon nanotubes (CNTs) and carbon micro-fibers (CMFs) are determined. Silica fume and a polymer with polyalkylene glycol graft chains were used as dispersant agents for the incorporation of the CNTs and CMFs into the cement paste. The mechanical properties of the mortar composites were investigated with respect to their flexural and compressive strength. A four-probe method was used for the estimation of their piezoresistive response. The test outcomes revealed that the combination of the dispersant agents along with a low content of CNTs and CMFs by weight of cement (bwoc) results in the production of a stronger mortar with enhanced mechanical performance and durability. More specifically, there was an increase in flexural and compressive strength of up to 38% and 88%, respectively. Moreover, mortar composites loaded with 0.4% CMF bwoc and 0.05% CNTs bwoc revealed a smooth and reversible change in electrical resistivity vs. compression loading—with unloading comprising a strong indication of self-sensing behavior. This work aims to accelerate progress in the field of material development with structural sensing and electrical actuation via providing a deeper insight into the correlation among cementitious composite preparation, admixture dispersion quality, cementitious composite microstructure and mechanical and self-sensing properties.

Enhanced perturb and observe control for addressing power loss under rapid load changes using a buck–boost converter

Many researchers have focused on improving the efficiency of photovoltaic (PV) systems by enhancing their control mechanisms to more consistently operate in the PV panels’ maximum power points. The predominant method used in these studies is the Perturb and Observe (P&O) method. However, this method faces challenges of drift when encountering rapid changes in resistive load, which completely inhibits them from addressing the problem of power loss. Additionally, the traditional P&O method suffers from oscillation issues. Here, an innovative control method is presented to improve the duty cycle and enable the handling of the challenges associated with sudden and rapid changes in resistive loads. A buck-boost power converter is implemented as an impedance adaptor to maintain operation at the maximum power point. The efficiency of the proposed modified P&O algorithm was evaluated using MATLAB software and compared to the traditional P&O algorithm across various operating scenarios. The simulation results show that the proposed method is significantly more efficient and effective than the traditional P&O algorithm, indicating its potential to enhance the efficiency of PV systems and increase their ability to adapt to changes in resistive load.

Flexible Tribo‐Enhanced Piezoelectric Nanogenerator Based on Aluminium Ferrite Electrospun Hybrid Nanofibers for Energy Harvesting and Patient Rehabilitation Application

AbstractMechanical energy harvesters have recently emerged as promising options for self‐powering sensors and small electronic devices. In this work, aluminum ferrite (AlFeO3)/PVDF hybrid perovskite electrospun nanofiber‐based tribo‐enhanced piezoelectric nanogenerators (TPENGs) are developed for energy harvesting. The as‐fabricated TPENG achieves an average voltage output of 52.3 V and an average current output of 1.23 µA. Additionally, the power density of the TPENG is calculated to be 0.085 W.m−2 at an 80 MΩ external resistance load. A 3D‐printed device is fabricated, containing nylon fabric (tribo‐positive) as a rotor attached to printed fins, while six (AlFeO3)/PVDF hybrid perovskite electrospun nanofiber piezoelectric nanogenerators (PENGs) wrapped with Kapton tape (tribo‐negative) serve as the stator. The three printed fins of the device are moved by a string‐based pulley, generating an open circuit voltage of 200 V and a short circuit current of 4.5 µA. The as‐fabricated 3D‐printed device with TPENGs is used to power small electronics (e.g., LEDs and watch) and an exercise setup, allowing patients to generate power by pulling the attached string, thereby estimating the level of impairment. Integrating energy harvesting into rehabilitation motivates patients to move impaired body parts, enhancing TPENG's application in healthcare as a practical and engaging tool for patient rehabilitation.

Ethylcellulose and bismuth sodium titanate-barium zirconate titanate (BNT-BZT) composite fibers for triboelectric energy harvesting

Green cellulose and toxic-free/rare earth-free nanomaterials are promising towards the development of triboelectric nanogenerators (TENGs) as energy harvesters for sustainable electronics. In this study, ethylcellulose (EC) and bismuth sodium titanate-barium zirconate titanate (BNT-BZT) are used as raw materials. An EC and BNT-BZT composite fiber mat was prepared by electrospinning and used as a positive triboelectric layer in a friction nanogenerator, while fluorinated ethylene propylene (FEP) was used as a negative triboelectric layer. After optimizing the electrospinning parameters and characterizing the materials, the developed TENG output power was studied as a function of the BNT-BZT doping concentration in the EC. At 2 wt% of doping, the output voltage of the TENG has a 3-fold increase compared with that obtained with a pure EC mat as the positive triboelectric layer. In addition, the TENG showed good output performance and operating stability after exposure to high temperature (70 ºC) and relative humidity (90 %). The maximum output power density of 134 μW/cm2 was obtained at a load resistance of 210 MΩ, showing good prospects in powering Internet of Things (IoT) sensor nodes.

Coordinated Control of Constant Output Voltage and Maximum Efficiency in Wireless Power Transfer Systems

This article presents a coordinated control method used for wireless power transfer (WPT) systems. This method can improve WPT system transmission efficiency while maintaining the constant output voltage. First, the topology of the DC–DC converter is selected and the equivalent circuit model of the WPT system is established. Then, the WPT system characteristics are discussed and the mutual inductance estimation process is presented. Furthermore, the coordinated control method is proposed, where the constant voltage output is achieved by connecting the Buck–Boost converter after the diode rectifier. Meanwhile, the optimal phase shift angle is calculated and sent to the controller to achieve maximum transmission efficiency tracking control, according to the measured load voltage and current. Finally, simulations and experiments are adopted to verify the proposed coordinated control method. The experimental results indicate that the average system transmission efficiency is increased by 1.80% and the efficiency fluctuation is decreased by 2.67% when the system load resistance varies, while the average system transmission efficiency is increased by 1.80%, and the efficiency fluctuation is decreased by 3.14% when the mutual inductance changes. This means the proposed coordinated control method is effective under the conditions of the WPT load and mutual inductance variations.

Operational Verification of DC-DC Converters Used in Ecologically Sound Non Polluting Renewable Systems

This research delves into the intricate control mechanisms governing renewable energy sources through the application of three distinct DC-DC converter technologies: the buck, boost, and buck-boost converters. Renewable energy sources like wind and solar can be pivotal in the future and become the primary source of energy for global energy requirements. Renewable sources are pollution-free and have minimal impact on the environment. This research illuminates the efficacy of these converters in orchestrating the optimal utilization of renewable energy sources, offering valuable contributions to the advancement of sustainable power systems. Open and closed loop control of a buck converter is studied along with its operation for the voltage regulation of an emulated PV panel. For the boost converter, a comprehensive exploration ensues through two closed-loop control methods: Perturb and Observe (P&O) algorithm and the incremental conductance method. Simulations are meticulously executed in MATLAB Simulink, interfacing with PV arrays and directing power toward battery charging. Meanwhile, the buck-boost converter undergoes simulation and evaluation, fed by a DC source and delivering power to a resistive load. Experimental validation is conducted for the buck converter, providing tangible insights into real-world performance. Conventional sources, primarily coal, which is the most used source of energy in Asian countries, including India, have adverse effects on the environment. Coal contributes to a huge proportion of pollutants in the environment and also the release of large quantities of greenhouse gases. Renewable energy resources can play a huge role in addressing the energy demands of Asian countries. They hold the ability to alleviate the environmental burden caused by conventional energy sources. Renewable energy sources also mitigate pollution and eliminate various hazardous effects of conventional energy sources. This study emphasises the adoption of such sources and underscores the pivotal role of DC-DC converter technologies in this adoption.

Design of electrical energy harvesting devices utilizing air bubbles sliding along a fluoropolymer immersed in water

Recent research has shown that it is possible to utilize contact electrification combined with electrostatic induction to harvest electrical energy from the mechanical motion of air bubbles sliding along a charged solid surface immersed in water. The working principle of these devices is simple, but the design is usually complicated as transduction efficiency depends on a number of interdependent parameters. Here we propose a simple analytical model and demonstrate how it can be used to determine the optimal energy per bubble for a given resistive load. The model allows one to estimate the optimal energy harvested per bubble in terms of polymer thickness, electrode separation and load resistance. It is shown that the model provides a good fit to experimental data. The model may be used as an initial step when designing energy harvesting devices utilizing air bubbles sliding along a solid surface.

Experimental results of a 330 GW impedance-matched Marx generator

Impedance-matched Marx generators (IMGs) are considered next generation pulsed-power drivers because of their long lifetime (> 10,000 shots), repetition rate (> 0.1-Hz), fast rise time (~ 100-ns), and high-energy-delivery efficiency (~ 90%). “TITAN” is a 14-stage IMG designed to deliver 1-TW to a 2-Ω matched load. In this paper, design, simulation, and experimental results for six stages of TITAN including its triggering system, air delivery system, and pulse shaping are presented. To achieve efficiency over 85% and maximize the capability of an IMG, synchronized triggering, reduced pre-fire rate, and pulse shaping ability are crucial. In this paper, novel engineering solutions are introduced, tested, and proven to overcome those challenges. 6-stage TITAN, powered by 102 identical bricks and 102 field-distortion-triggered gas switches, could generate ~ 600-kA and ~ 700-kV across a ~ 0.9-Ω matched load when fully charged to ± 100-kV. In these experiments, 6-stage TITAN is tested up to ± 70-kV charge voltage which delivers a peak power of 330-GW to a 1.2-Ω resistive load.

Seasonal Muscular Power Changes: Considerations of Concurrent Resistance and Field-Based Training in Professional Rugby League.

Redman, KJ, Wade, L, Whitley, R, Connick, MJ, Kelly, VG, and Beckman, EM. Seasonal muscular power changes: considerations of concurrent resistance and field-based training in professional rugby league. J Strength Cond Res 38(9): 1620-1626, 2024-A rugby league player's ability to develop or maintain lower-body power will be significantly influenced by the resistance and field-based training loads completed. This study aimed to examine the power changes across a rugby league season and to investigate the relationship of concurrent training and training experience on power changes. Eighteen rugby league players participated in this study. Lower-body power was evaluated using a countermovement jump throughout the season. Four measures of external training loads were collected. A Friedman's test was used to assess differences in power throughout different phases of the season. A series of Spearman's rank-order correlations were conducted to assess the relationship between percentage changes in power during the training block, external training loads, and training experience. Countermovement jump peak velocity significantly decreased from the start ( p = 0.006) and end of pre-season ( p = 0.022) to the late competition. Correlation analysis revealed a large significant association between early competition field-based external loads (relative ( rs = -0.571) and total distance ( rs = -0.628)) and change in peak power. Very large significant negative relationships were also observed between mid-competition volume load with change in peak force ( rs = -0.825) and peak power ( rs = -0.736). Training experience was not significantly associated with changes in muscular power variables throughout this study. Coaches should seek to monitor changes in peak power when competition begins and to assist with decision-making for potential adjustments to running volume and intensity during field-based sessions.

Frequency-dependent electrochemical breakdown of hydrogel ionotronics

When an ionic conductor meets an electronic conductor, ions and electrons couple at the interface between ionic and electronic circuits, enabling a class of devices: ionotronics. Such a coupling gives innovations but can cause electrochemical breakdown. Rapid advances in hydrogel ionotronics, in which hydrogel serves as stretchable, transparent, ionic conductor, highlight an urgent need: a general approach and criterion to study electrochemical breakdown under AC condition. Here we study the breakdown behavior of a metal-hydrogel-metal ionotronic system subject to alternating voltages of various frequencies and amplitudes. First, we apply a sinusoidal voltage to the ionotronic system which is connected in series to a load resistor, and compare the waveforms of the applied voltage and the output voltage between the two ends of the load resistor at various frequencies and amplitudes. Electrochemical breakdown tends to take place at low frequencies and high amplitudes, and causes distortion of waveform of the output voltage. Next, we develop an electric circuit model, in which each hydrogel-metal junction is modeled as a constant phase element in parallel with a leakage resistor and the hydrogel is modeled as a resistor. Our experiments show that the electrochemical window is insensitive to the frequency and amplitude of applied voltage, as well as to the concentration of ions in the hydrogel. Through a combination of experiment and theory, we further propose a frequency-amplitude phase diagram. Different from DC condition, the breakdown behavior under AC condition depends not only on the amplitude of applied voltage, but also on the frequency of applied voltage. We also show that electrochemical reaction can be retarded by stretching the hydrogel and by increasing the frequency. It is hoped that this work will guide the development of stable and reliable hydrogel ionotronic devices.

Modifying the Characteristics of the Electrical Arc Generated during Hot Switching by Reinforcing Silver and Copper Matrices with Carbon Nanotubes

Switching elements are crucial components in electrical and electronic systems that undergo severe degradation due to the electrical arc that is generated during breaking. Understanding the behavior of the electrical arc and modifying its characteristics via proper electrode design can significantly improve durability while also promoting optimal performance, reliability, and safety in circuit breakers. This work evaluates the feasibility of carbon nanotube (CNT)-reinforced silver and copper metal matrix composites (MMCs) as switching electrodes and the influence of CNT concentration on the characteristics of the arcs generated. Accordingly, three different concentrations per MMC were manufactured via powder metallurgy. The MMCs and reference materials were subjected to a single break operation and the electrical arcs generated using 100 W and 200 W resistive loads were analyzed. The proposed MMCs displayed promising results for application in low-voltage switches. The addition of CNTs improved performance by maintaining the arc’s energy in the silver MMCs and reducing the arc’s energy in the copper MMCs. Moreover, a CNT concentration of at least 2 wt.% is required to prevent unstable arcs in both metallic matrices. Increased CNT content further promotes the splitting of the electrical arc due to a more complex phase distribution, thereby reducing the arc’s spatial energy density.

A Deep Reinforcement Learning Approach to DC-DC Power Electronic Converter Control with Practical Considerations

In recent years, there has been a growing interest in using model-free deep reinforcement learning (DRL)-based controllers as an alternative approach to improve the dynamic behavior, efficiency, and other aspects of DC–DC power electronic converters, which are traditionally controlled based on small signal models. These conventional controllers often fail to self-adapt to various uncertainties and disturbances. This paper presents a design methodology using proximal policy optimization (PPO), a widely recognized and efficient DRL algorithm, to make near-optimal decisions for real buck converters operating in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) while handling resistive and inductive loads. Challenges associated with delays in real-time systems are identified. Key innovations include a chattering-reduction reward function, engineering of input features, and optimization of neural network architecture, which improve voltage regulation, ensure smoother operation, and optimize the computational cost of the neural network. The experimental and simulation results demonstrate the robustness and efficiency of the controller in real scenarios. The findings are believed to make significant contributions to the application of DRL controllers in real-time scenarios, providing guidelines and a starting point for designing controllers using the same method in this or other power electronic converter topologies.

Resistance to protease inhibitors among persons living with HIV in Ghana: a case for viral load and drug resistance monitoring

ObjectiveRoutine viral load and drug resistance testing are well supported in most resource-rich settings and provide valuable benefits in the clinical care of PLWH in these communities. Undoubtedly, there exist financial and political constraints for the scale-up of viral load and drug resistance testing in Sub-Saharan Africa. To achieve the global UNAIDS 95/95/95 targets, there is the need to bridge this inequity in patient care and allow for a universal approach that leaves no community behind.MethodsVenous blood from 96 PLWH on second-line ART from Korle-Bu Teaching Hospital were collected and processed into plasma for CD4+ T- cell and viral load assessments. Ribonucleic acid (RNA) was extracted from stored plasma and the protease gene amplified, sequenced and analyzed for subtype and drug resistance mutations using the Stanford HIV drug resistance database.ResultsOut of the 96 PLWH, 37 experienced virological failure with 8 patients’ samples successfully sequenced. The predominant HIV-1 subtype identified was CRF02_AG (6/8, 75.0%) with 12.5% (1/8) each of CFR06_cpx infection and one case unable to subtype. The major PI resistance mutations identified were; M46I, I54V, V82A, I47V, I84V and L90M.ConclusionsPersons living with HIV who had experienced virologic failure in this study harboured drug resistance mutations to PI, thus compromise the effectiveness of the drugs in the second line. Resistance testing is strongly recommended prior to switching to a new regimen. This will help to inform the choice of drug and to achieve optimum therapeutic outcome among PLWH in Ghana.