Design Of Simulator Research Articles

Machine learning-augmented fluid dynamics simulations for micromixer educational module.

Micromixers play an imperative role in chemical and biomedical systems. Designing compact micromixers for laminar flows owning a low Reynolds number is more challenging than flows with higher turbulence. Machine learning models can enable the optimization of the designs and capabilities of microfluidic systems by receiving input from a training library and producing algorithms that can predict the outcomes prior to the fabrication process to minimize development cost and time. Here, an educational interactive microfluidic module is developed to enable the design of compact and efficient micromixers at low Reynolds regimes for Newtonian and non-Newtonian fluids. The optimization of Newtonian fluids designs was based on a machine learning model, which was trained by simulating and calculating the mixing index of 1890 different micromixer designs. This approach utilized a combination of six design parameters and the results as an input data set to a two-layer deep neural network with 100 nodes in each hidden layer. A trained model was achieved with R2 = 0.9543 that can be used to predict the mixing index and find the optimal parameters needed to design micromixers. Non-Newtonian fluid cases were also optimized using 56700 simulated designs with eight varying input parameters, reduced to 1890 designs, and then trained using the same deep neural network used for Newtonian fluids to obtain R2 = 0.9063. The framework was subsequently used as an interactive educational module, demonstrating a well-structured integration of technology-based modules such as using artificial intelligence in the engineering curriculum, which can highly contribute to engineering education.

Macroeconomic impact of agricultural financing reforms: a computable general equilibrium analysis of Nigeria

Purpose- The study analyzed the macroeconomic impact of agricultural financing reforms: a computable general equilibrium analysis of Nigeria. Specifically, the study evaluated the macroeconomic impact of the agricultural financing reforms on economic growth, and agricultural output. Methodology- This study employed time series data from secondary sources such as the Central Bank of Nigeria (CBN), the National Bureau of Statistics' (NBS) in conjunction with the World Bank Living Standard Measurement Study (LSMS) and Information from the Nigerian Living Standard Survey for 2019 was used to obtain shares of household income and expenditure which covered the period 2010-2022. Applying the economy-wide methodology of Computer General Equilibrium model on reformatted upgraded Social Accounting Matrix for Nigeria, Simulation Designs, and t- test. Findings- The study finds that agricultural financing reforms through a decrease in interest rates on agricultural loans by 10% and 8% have positive significant impact on economic growth. The results of the study also reveal that agricultural financing reforms through a decrease in interest rates on agricultural loans by 10% and 8% have positive significant impact on agricultural output. Conclusion- The two policy scenarios (10% and 8% reduction in interest rate on agricultural loans) were simulated and the results for both cases indicated that all the macroeconomic indicators increased significantly due to the policy options. Keywords: Macroeconomic impact, agricultural financing reforms, computable general equilibrium analysis, economic growth, Nigeria. JEL Codes: A11, B23, B41, C53, E47

Evaluating the wear of cutting tools using a tunnel boring machine laboratory simulator

Purpose. One of the most common problems in mechanized excavation is the cutting tool wear, which has a great impact on the final cost of the project and its duration. Also, one of the most important factors affecting the wear of cutting tools is the operating parameters of the tunnel boring machine (TBM). Within the framework of this research, a tunnel boring machine laboratory simulator was designed and constructed to investigate the tunnel excavation process in the laboratory. Methods. A few of the features of this device are that it operates horizontally, has a low rotation speed, keeps the pins in contact with fresh soil throughout the test, and has the possibility of measuring the torque of the device during the test. A study of the cutting tool wear was conducted using granulation prepared from Tabriz metro line 2, as well as using operating parameters of mechanized excavation machines, such as penetration rate and cutter head rotation speed. Findings. The research results showed that by reducing the rotation speed of the cutter head from 35 to 10 rpm, the average wear of cutting tools is reduced by 63%. Also, by reducing the excavation time from 80 to 10 minutes, the cutting tool wear is reduced by 58%. The wear of cutting tool increases with increasing moisture content from 0 to 10%, and then decreases with increasing moisture content from 10 to 25%. Originality. During this research, a new device was designed and built to simulate tunnel excavation mechanisms. This laboratory simulator measures wear percentage, penetration rate and torque. Practical implications. There has been significant progress in predicting soil abrasion rates, but there are few accepted models for predicting cutting tool wear and soil abrasion rates. During the design and construction of the tunnel boring machine laboratory simulator, the effect of operating parameters on wear of cutting tool was examined.

PERFORMANCE ANALYSIS AND SPEED CONTROL USING INDIRECT VECTOR CONTROLLED FOR INDUCTION MOTOR DRIVES

This paper presents the speed control scheme of an indirect vector-controlled induction motor (IM) drive. PWM controlling scheme is based on Voltage source inverter type space vector pulse width modulation (SVPWM) and the Conventional-PID controller or Fuzzy-PID controller is employed in closed-loop speed control. Decoupling of the stator current into torque and flux producing (d-q) current components model of an induction motor is involved in the indirect vector control. The torque component Iq current of an IM is developed by an intelligent-based Fuzzy PID controller. Based on settling time and dynamic response the performance of the Fuzzy Logic Controller is compared with that of the PID Controller to sudden load changes. It provides better control of motor torque with high dynamic performance. The simulated design is tested using various toolboxes in MATLAB. Simulation results of both controllers are presented for comparison.

A Hemodynamic Pulse Wave Simulator Designed for Calibration of Local Pulse Wave Velocities Measurement for Cuffless Techniques.

Devices for cuffless blood pressure (BP) measurement have become increasingly widespread in recent years. Non-invasive continuous BP monitor (BPM) devices can diagnose potential hypertensive patients at an early stage; however, these cuffless BPMs require more reliable pulse wave simulation equipment and verification methods. Therefore, we propose a device to simulate human pulse wave signals that can test the accuracy of cuffless BPM devices using pulse wave velocity (PWV). We design and develop a simulator capable of simulating human pulse waves comprising an electromechanical system to simulate the circulatory system and an arm model-embedded arterial phantom. These parts form a pulse wave simulator with hemodynamic characteristics. We use a cuffless device for measuring local PWV as the device under test to measure the PWV of the pulse wave simulator. We then use a hemodynamic model to fit the cuffless BPM and pulse wave simulator results; this model can rapidly calibrate the cuffless BPM's hemodynamic measurement performance. We first used multiple linear regression (MLR) to generate a cuffless BPM calibration model and then investigated differences between the measured PWV with and without MLR model calibration. The mean absolute error of the studied cuffless BPM without the MLR model is 0.77 m/s, which improves to 0.06 m/s when using the model for calibration. The measurement error of the cuffless BPM at BPs of 100-180 mmHg is 1.7-5.99 mmHg before calibration, which decreases to 0.14-0.48 mmHg after calibration. This study proposes a design of a pulse wave simulator based on hemodynamic characteristics and provides a standard performance verification method for cuffless BPMs that requires only MLR modeling on the cuffless BPM and pulse wave simulator. The pulse wave simulator proposed in this study can be used to quantitively assess the performance of cuffless BPMs. The proposed pulse wave simulator is suitable for mass production for the verification of cuffless BPMs. As cuffless BPMs become increasingly widespread, this study can provide performance testing standards for cuffless devices.

Design of a rainfall simulator for classroom demonstration and field research

AbstractRainfall is a key abiotic factor of ecosystems that can both provide benefits and contribute to negative environmental impacts. Due to spring precipitation levels increasing in the Midwest, there has been increased interest in developing and evaluating practices that can mitigate the effects of heavy rainfall. As this is an area of interest for both agriculture and environmental sciences, demonstrating the actions of severe rainfall can be a powerful tool in the natural sciences classroom as well as in the field. Rainfall simulators are ideal for this demonstration as they can create repeated, uniform rainfall events while introducing limited variability between events. Building on previous literature, we constructed a cost‐effective, easily transportable design that can be utilized in the classroom, the lab, and the field. Here, tests were conducted to measure flow rate, rain droplet size, and uniformity of water dispersion on the cost‐effective and easily obtained solid cone‐style herbicide nozzle. We found no statistically significant differences among rainfall dispersion metrics or in raindrop uniformity analyses. This demonstrates the capability of constructing this type of teaching and research equipment at little cost while producing highly consistent and size‐relevant artificial rainfall.

Massively multiplex blocker displacement amplification (BDA) for the detection of measurable residual disease in acute myeloid leukemia.

e19045 Background: Next-generation sequencing (NGS) technologies, used to accomplish high throughput characterization of DNA, have an inherent error rate of between 0.1-1%. However, many important DNA sequences possess variant allele frequencies (VAFs) below this rate, potentially precluding their detection and identification by NGS. The previously published blocker displacement amplification (BDA) research technology has enabled selective amplification of sequences with variants, facilitating detection by NGS of these sequences with low VAFs at low read depths. Methods: Here we present the massively multiplex BDA library preparation method for the NGS-based detection of low VAF sequences. By optimizing our previously published Simulated Annealing Design using Dimer Likelihood Estimation (SADDLE) algorithm, we designed a 4 tube assay, comprising up to ~2400 amplicons in each tube, and ~8300 total amplicons. Tube 1 was designed with the highest likelihood of on-target amplification and the lowest likelihood of dimerization or non-specific amplification. While Tube 1 targeted ~1000 regions covering the most-frequently observed mutations in current public databases of patients with acute myeloid leukemia (AML) across more than 200 genes, Tubes 2-4 were designed for enrichment of the full coding sequence of 63 genes. To highlight the performances of SADDLE, coverage uniformity, primer dimerization, and non-specific amplification of tube 1 were compared to those of a naively designed tube. The panel was further tested with contrived and reference samples to demonstrate its analytical performance. Results: The SADDLE algorithm design decreased the first pass amplicon dropout rate more than 10-fold, from 30% to ~2%, and further improved the overall on-target rate compared to the naively designed panel. Through SADDLE, we were able to achieve an 80% median coverage of 63 genes. The resulting panel has a bulk limit of detection (LoD) of below 0.1% VAF. Conclusions: Massively multiplex BDA enabled the NGS characterization of DNA targets with VAFs suitable for detection of AML measurable residual disease (MRD). This technology represents a 100-fold increase in current plexity for the detection of low VAF alleles over our previously published multiplex BDA technology, demonstrating the ability to perform high throughput sequencing of rare mutations.

Wideband and Low-Profile Multi-Polarization Reconfigurable Filtering Antenna Based on Nonuniform Metasurface

In this article, a wideband and low-profile multi-polarization reconfigurable filtering antenna based on metasurface (MS) is investigated. The proposed antenna consists of two layers, which are the feeding layer and the MS layer. The filtering function is achieved by utilizing a non-uniform MS and inserting a short via between the feedline and ground plane. Besides, by rotating the MS to change its surface current distribution, the antenna can switch among linear polarization (LP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP). To demonstrate the simulated design, the proposed antenna is manufactured and measured. As the measured results show, when the antenna works in LP modes, it obtains an -10-dB overlapped impedance bandwidth of 22.4% and an in-band peak gain of 8.8 dBi. Furthermore, the antenna achieves 14-dB and 19-dB out-of-band radiation suppression levels for LP1 and LP2 modes, respectively. Whereas it operates in CP modes, the measured -10-dB overlapped impedance bandwidth and 3-dB axial ratio (AR) bandwidth of the antenna reach 26.5% and 22%, respectively. Meanwhile, its out-of-band radiation suppression level is more than 17.5 dB, with an in-band peak gain of 7.3 dBic. Hence, there illustrates a pretty good agreement between the simulated and measured results.

Development and Research of a Medium Vertical Dipole Electromagnetic Pulse Simulator

In this paper, the design of a self-developed EMP simulator with a 5 m height and an inverted conducting mono-cone antenna with a cone half-angle of 32° is introduced. The experimental region of the simulator is a circular area of 25 m in diameter around the cone vertex. Two feeding modes, feed-in over the ground and feed-in under the ground, are realized by two different high-voltage pulse sources. It can be concluded through radiation field testing that the radiation field waveform generated by the simulator has a rise time of 2–3 ns and a half-width of about 25 ns, meeting the specifications of the EMP experimental waveform in the IEC61000-2-9 standard. Meanwhile, the differences between the engineering implementation of the simulator and its ideal structure during the design process can lead to some distortion issues in the antenna radiation characteristics and the electromagnetic radiation field it generates. The radiation field waveform and the distribution of the EMP field generated by the simulator under different feeding methods, antenna wire quantities, antenna end processing methods, and different antenna resistive loading were studied, and the changes in the radiation field waveform and field distribution with different angles and distances of the monitoring point were analyzed. Based on the measurement results, the radiation characteristics of the antenna and the factors that affect the waveform of the field were studied and analyzed. Through the aforementioned work, a comprehensive understanding of the performance, radiation characteristics, and engineering factors affecting the electromagnetic environment generated by the simulator has been obtained. On this basis, the parameters of the antenna wire quantity, antenna end processing method, and test point position of the designed simulator were reconfirmed and optimized. In summary, this work has important reference significance for mastering the development technology of such simulators, understanding their antenna radiation characteristics, and conducting EMP-related assessments and effect experiments in the future.

Studies on Finite Element Analysis in Hydroforming of Nimonic 90 Sheet

The primary goal of this study was to investigate the formability of Nimonic 90 sheet which performs well at high temperatures and pressures, making it ideal for applications in the aerospace, processing, and manufacturing industries. In this present study, finite element analysis (FEA) and optimization of process parameters for formability of Nimonic 90 in sheet hydroforming were investigated. The material’s mechanical properties were obtained by uniaxial tensile tests as per the standard ASTM E8/E8M. The sheet hydroforming process was first simulated to obtain maximum pressure (53.46 MPa) using the FEA and was then validated using an experiment. The maximum pressure obtained was 50.5 MPa in experimentation. Since fully experimental or simulation designs are impractical, the Box–Behnken design (BBD) was used to investigate various process parameters. Formability was measured by the forming limit diagram (FLD) and maximum deformation achieved without failure. Analysis of variance (ANOVA) results also revealed that pressure and thickness were the most effective parameters for achieving maximum deformation without failure. Response surface methodology (RSM) optimizer was used to predict optimized process parameter to achieve maximized response (deformation) without failure. Experimental validation was carried out for the optimized parameters. The percentage of error between experimental and simulation results for maximum deformation was less than 5%. The findings revealed that all the aspects in the presented regression model and FEM simulation were effective on response values.

Variability of tissue mechanical response in Sus Domesticus porcine models from in vivo to ex vivo conditions.

Healthcare simulators have been demonstrated to be a valuable resource for training several technical and nontechnical skills. A gap in the fidelity of tissues has been acknowledged as a barrier to application for current simulators; especially for interventional procedures. Inaccurate or unrealistic mechanical response of a simulated tissue to a given surgical tool motion may result in negative training transfer and/or prevents the "suspension of disbelief" necessary for a trainee to engage in the activity. Thus, where it is relevant to training outcomes, there should be an effort to create healthcare simulators with simulated tissue mechanical responses that match or represent those of biological tissues. Historically, this data is most often gathered from preserved (post mortem) tissue; however, there is a concern that the mechanical properties of preserved tissue, that lacks blood flow, may lack adequate accuracy to provide the necessary training efficacy of simulators. This work explores the effect of the "state" of the tissue testing status on liver and peritoneal tissue by using a customized handheld grasper to measure the mechanical responses of representative porcine (Sus domesticus) tissues in n = 5 animals across five test conditions: in vivo, post mortem (in-situ), ex vivo (immediately removed from fresh porcine cadaver), post-refrigeration, and post-freeze-thaw cycle spanning up to 72 hours after death. No statistically significant difference was observed in the mechanical responses due to grasping between in vivo and post-freeze conditions for porcine liver and peritoneum tissue samples (p = 0.05 for derived stiffness at grasping force values F = 5N and 6.5N). Furthermore, variance between in vivo and post-freeze conditions within each animal, was comparable to the variance of the in vivo condition between animals. Results of this study further validate the use of preserved tissue in the design of medical simulators via observing tissue mechanical responses of post-freeze tissue comparable to in vivo tissue. Therefore, the use of thawed preserved tissue for the further study and emulation of mechanical perturbation of the liver and peritoneum can be considered. Further work in this area should investigate these trends further, particularly in regard to other tissues and the potential effects varying preservation methods may yield.

Modelling and analysis of contactless sensor for TSV fault based on resonant inductive coupling

In order to solve the problems of inefficient detection, high cost, and high damage rate of existing Through Silicon Via (TSV) contact detection, contactless testing techniques are urgently needed to eliminate the many problems associated with contact. In this paper, a contactless antenna utilizing resonant inductive coupling is presented. This coupling method, as compared to the conventional capacitive coupling technique allows faults detect from longer distances. The results of 3D full wave simulations in the High Frequency Structure Simulator (HFSS) and Advanced Design System (ADS) show that various faults, such as voids and pinholes, can be detected when the distance between the TSV and the antenna remains about 10 μm. Defective TSVs cause changes in the operating current and voltage pulses at the detection antenna. Simultaneously, changes in the field distribution around the TSVs are used to explain the changes in current and voltage pulses. Furthermore, the effects of antenna parallel movement were also investigated.

Demonstration of a Wideband Multipolarization Transmitarray Antenna for Satellite Communication

To meet the requirements of satellite communication (SATCOM), in this paper, a wideband high stability transmitarray antenna (TA) for SATCOM is proposed. The TA is composed of 225 metal-only unit cells that comprise three metallic layers with an air spacer in between. High stability is capable by adopting a simple metallic square loop and two pairs of orthogonal stubs with a 1 mm thickness of the layer, which ensures lower assembly complexity and higher integration. The proposed unit cell can also support linear polarization (LP) wave excitation and circular polarization (CP) wave excitation simultaneously. Meanwhile, the metal-only unit cell can operate without dielectric loss, which leads to higher working efficiency. By adjusting feature sizes, eight different kinds of the unit cell are designed to realize a 3-bit TA which enables obtaining a gain of 23.53 dBi. Finally, four TA prototypes have been fabricated and tested successfully. The measured result shows a 28.5% 3 dB gain bandwidth from 30 GHz to 40 GHz, which is in good consistency with the simulated design. This compact and mechanical robustness design provides an alternative proposal for SATCOM.

Three-way gravity models with multiplicative unobserved effects

Summary This paper investigates three-way gravity models with multiplicative unobserved effects, which are popular in bilateral trade analysis and many other contexts. Such models are usually estimated by the fixed effects Poisson pseudo maximum likelihood method. As an alternative, we extend the estimation strategy proposed by Jochmans (2017) to our new settings by constructing moment conditions that are independent of the unobserved effects. Our method entails estimation of the conditional mean of a variety of functional forms. The generalized method of moments (GMM) estimator based on these moment conditions is N-consistent and asymptotically normally distributed. We also discuss the estimation of dynamic models by extending the linear feedback models to our three-way settings. Through various simulation designs, we show that our GMM estimator outperforms the competing Poisson pseudo maximum likelihood estimator. As an empirical application, we estimate the effects of the currency unions on exports.

Design of a 1-MHz therapeutic ultrasound array for small volume blood-brain barrier opening at cortical targets in macaques.

Focused ultrasound (FUS) can temporarily open the blood brain barrier (BBB) and increase the delivery of chemotherapeutics, viral vectors, and other agents to the brain parenchyma. To limit FUS BBB opening to a single brain region, the transcranial acoustic focus of the ultrasound transducer must not be larger than the region targeted. In this work, we design and characterize a therapeutic array optimized for BBB opening at the frontal eye field in macaques. We used 115 transcranial simulations in four macaques varying f-number and frequency to optimize the design for focus size, transmission, and small device footprint. The design leverages inward steering for focus tightening, a 1 MHz transmit frequency, and can focus to a simulation predicted 2.5 ± 0.3 mm lateral and 9.5 ± 1.0 mm axial full-width at half maximum spot size at the frontal eye field without aberration correction. The array is capable of steering axially 35 mm outward, 26 mm inward, and laterally 13 mm with > 50% the geometric focus pressure. The simulated design was fabricated, and we characterized the performance of the array using hydrophone beam maps in a water tank and through an ex vivo skull cap to compare measurements with simulation predictions, achieving a 1.8 mm lateral and 9.5 mm axial spot size with a transmission of 37 % (transcranial, phase corrected). The transducer produced by this design process is optimized for BBB opening at the frontal eye field in macaques.

Design and development of a new metamaterial sensor-based Minkowski fractal antenna for medical imaging

The metamaterial sensor antenna is numerically designed to detect breast cancer using breast cancer cell lines, especially relying on the electrical characteristics of breast cancer cells, and designed antenna is measured and the results are observed. The metamaterial sensor antenna is a simple and efficient antenna which is designed using the Minkowski fractal curve with a ring-shaped Split Ring Resonator (SRR). The SRR is chosen because of its inductive and capacitive resonating properties. In addition, the Minkowski fractal curve is used as a defective ground structure to improve sensor sensitivity and selectivity. The numerical investigations are based on different iterations of the Minkowski fractal curve. In that iteration, the third iteration of the Minkowski fractal gives better results. The designed antenna is tested with breast cancer cell lines, and it resonates at a frequency of 2.35, 2.42, and 2.52 GHz for different dielectric constants and conductivity. The simulated design antenna is tested with different cancer cell lines like MDA-MB-231, MCF-7, and HS758-T to ensure its performance and selectivity. The measured result of the fabricated antenna shows that the antenna design resonates at the same frequency as the simulated antenna results.

Effect of Component Position and Inward–Outward Rotation on the Wear of Different Ultra-High Molecular Weight Polyethylenes in an Orbital Bearing Type Hip Joint Simulator

The orbital bearing machine is the world’s most widely used hip joint simulator design for wear testing of prosthetic hips. It has been used with inverted and anatomic component position and with and without inward–outward rotation. Still the effect of component position on the wear of the most widely used bearing material, ultrahigh molecular weight polyethylene (UHMWPE), has not been studied directly. With a modified orbital bearing machine, the effects of the component position, anatomic versus inverted, and of the inward–outward rotation, present versus absent, on polyethylene wear were studied for the first time. Acetabular liners made from different ultra-high molecular weight polyethylenes articulated against alumina femoral heads in alpha calf serum. The inverted position resulted in the most realistic, burnished appearance of the polyethylene bearing surfaces. In the inverted position, the wear rate decreased with increasing gamma dose that is known to improve wear resistance by cross-linking. In the anatomic position, the bearing surface was not always entirely burnished. The wear was similar with and without inward–outward rotation. The mean wear rate of vitamin E stabilized highly cross-linked ultra-high molecular weight polyethylene was close to clinical observations. Clinically relevant wear could be produced with the orbital bearing machine for both established and advanced bearing materials. The inverted position appeared preferable in the orbital bearing machine. Inward–outward rotation did not appear important.

Fostering Adaptive Expertise Through Simulation.

Technology-enhanced simulation has been used to tackle myriad challenges within health professions education. Recently, work has typically adopted a mastery learning orientation that emphasizes trainees' sequential mastery of increasingly complex material. Doing so has privileged a focus on performance and task completion, as captured by trainees' observable behaviors and actions. Designing simulation in these ways has provided important advances to education, clinical care, and patient safety, yet also placed constraints around how simulation-based activities were enacted and learning outcomes were measured. In tracing the contemporary manifestations of simulation in health professions education, this article highlights several unintended consequences of this performance orientation and draws from principles of adaptive expertise to suggest new directions. Instructional approaches grounded in adaptive expertise in other contexts suggest that uncertainty, struggle, invention, and even failure help learners to develop deeper conceptual understanding and learn innovative approaches to novel problems. Adaptive expertise provides a new lens for simulation designers to think intentionally around how idiosyncrasy, individuality, and inventiveness could be enacted as central design principles, providing learners with opportunities to practice and receive feedback around the kinds of complex problems they are likely to encounter in practice. Fostering the growth of adaptive expertise through simulation will require a fundamental reimagining of the design of simulation scenarios, embracing the power of uncertainty and ill-defined problem spaces, and focusing on the structure and pedagogical stance of debriefing. Such an approach may reveal untapped potential within health care simulation.

SENSITIVITY OF LINER RIM PLASTIC DEFORMATION TO EDGE LOADING HIP SIMULATOR DYNAMICS

Variations in component positioning of total hip replacements can lead to edge loading of the liner, and potentially affect device longevity. These effects are evaluated using ISO 14242:4 edge loading test results in a dynamic system. Mediolateral translation of one of the components during testing is caused by a compressed spring, and therefore the kinematics will depend on the spring stiffness and damping coefficient, and the mass of the translating component and fixture. This study aims to describe the sensitivity of the liner plastic strain to these variables, to better understand how tests using different simulator designs might produce different amounts of liner rim deformation.A dynamic explicit deformable finite element model with 36mm Pinnacle metal-on-polyethylene bearing geometry (DePuy Synthes, Leeds, UK) was used with material properties for conventional UHMWPE. Setup was 65° clinical inclination, 4mm mismatch, 70N swing phase load, and 100N/mm spring. Fixture mass was varied from 0.5-5kg, spring damping coefficient was varied from 0-2Ns/mm. They were changed independently, and in combination.Maximum separation values were relatively insensitive to changes in the mass, damping coefficient, or both. The sensitivity of peak plastic strain, to this range of inputs, was similar to changing the swing phase load from 70N to approximately 150N – 200N. Increasing the fixture mass and/or damping coefficient increased the peak plastic strain, with values from 0.15-0.19.Liner plastic deformation was sensitive to the spring damping and fixture mass, which may explain some of the differences in fatigue and deformation results in UHMWPE liners tested on different machines or with modified fixtures. These values should be described when reporting the results of ISO14242:4 testing.AcknowledgementsFunded by EPSRC grant EP/N02480X/1; CAD supplied by DePuy Synthes.

Highly efficient color-control technique for building-integrated photovoltaics using optical dielectric thin film

A color-control technique based on optical thin films on glass is investigated by means of numerical simulation and experiment, with a particular focus on building-integrated photovoltaic (BIPV) applications. We show that white-colored BIPV modules can be realized with a minimum optical loss by applying optical thin films that have multiple reflection peaks in a complementary color relationship, like the emission spectrum of white LEDs. The angular dependence of hue, which is an inherent drawback of optical thin film systems, is suppressed by modifying the design of the film to maintain the complementary color relationship of multiple reflection peaks. The simulated thin film design is confirmed by an experiment with a silicon solar cell, resulting in a white color and a low short-circuit current density loss (ΔJ SC) of 5.9%. These results indicate that our approach is a promising way to realize fascinating colors and a high energy yield simultaneously in BIPV modules.