Preliminary Experimental Investigation Research Articles

Laser-sound reproduction by pulse amplitude modulation audio streams

Recently, the possibility to reproduce complex continuous acoustic signals via pulsed laser-plasma sound sources was demonstrated. This was achieved by optoacoustic transduction of dense laser pulse trains, modulated via single- or multi-bit Sigma–Delta, in the air or on solid targets. In this work, we extend the laser-sound concept to amplitude modulation techniques. Particularly, we demonstrate the possibility of transcoding audio streams directly into acoustic pulse streams by analog pulsed amplitude modulation. For this purpose, an electro-optic modulator is used to achieve pulse-to-pulse amplitude modulation of the laser radiation, similarly to the multi-level Sigma–Delta method. The modulator is directly driven by the analog input stream through an audio interface. The performance of the system is evaluated at a proof-of-principle level for the reproduction of test audio signals such as single tones, double tones and sine sweeps, within a limited frequency range of the audible spectrum. The results are supported by computational simulations of the reproduced acoustic signals using a linear convolution model that takes as input the audio signal and the laser-generated acoustic pulse profile. The study shows that amplitude modulation allows for significant relaxation of the laser repetition rate requirements compared to the Sigma–Delta-based implementation, albeit at the potential cost of increased distortion of the reproduced sound signal. The nature of the distortions is analyzed and a preliminary experimental and computational investigation for their suppression is presented.

Issues of gas film stability with performance characteristics in u-ECDM: A review of existing approaches and preliminary investigation on proposed stable & sustainable approach

Micro-featured devices (made of glass and its composites) are becoming increasingly necessary for Micro Electro-Mechanical Systems (MEMS) and healthcare devices with the emergence of technology. Due to limitations of existing methods, Micro Electro Chemical Discharge Machining (μ-ECDM) is an evolving technique for difficult to micro machine materials like glass. However, improper flushing and unstable electrolytic conditions in the processing zone percolates the efficacy, accuracy, and repeatability of μ-ECDM. Consequently, deteriorating the sustainability and industrial feasibility of this process. To cope up with these problems, various approaches like ultrasonic assistance, rotary mode, magneto hydrodynamic are integrated and investigated with μ-ECDM in the literature. Although these approaches achieved the intended objectives but do not assure the stability and sustainability of the process, which are essential for industrial feasibility in the present scenario. The present review has stressed upon the effects of existing approaches on gas film formation, discharge characteristics and performance outcomes. Systematic review methodology indicated the extensive usage of ultrasonic vibrations in μ-ECDM and, the studies on the stability/sustainability of μ-ECDM process are neglected. According to literature and preliminary investigation, problems pertaining to the rising electrolyte temperature and heterogeneous electrolyte concentration are the attributed reasons, which affects the stability as well as sustainability. Therefore, the present review proposed an innovative approach to achieve the stability and sustainability of μ-ECDM process by controlling the electrolytic conditions (termed as controlled-ECDM). A preliminary experimental investigation witnessed the enhancement of process performance and quality characteristics in controlled-ECDM.

Design, fabrication and validation of an electrical conductivity principle based two-phase detection sensor array for molten lead (Pb) based heavy metal coolants up to 600°C

Molten lead (Pb) and its alloys (PbBi and PbLi) are of immense interest for various nuclear engineering applications, including but not limited to advanced Lead-cooled Fast Reactors (LFRs), tritium Breeding Blankets (BBs) of fusion power plants and spallation targets for Accelerator-Driven Systems (ADS). Owing to their attractive thermophysical properties, these advanced fluids assert their candidacy to address the critical requirements of neutron multiplication, neutron moderation, high temperature coolants and tritium breeders, enabling the operation of next generation nuclear systems at high temperatures with better efficiencies. However, for numerous reasons such as a compromise of structural integrity at the heat transfer interface, presence of an inert cover gas during charging of molten metal in the loop, and the fusion fuel cycle itself may lead to molten metal-gas two-phase flows with high density ratios. At present, no effective diagnostics exist to detect such operational and accidental occurrences in high temperature molten metal systems resulting in a severe lack of relevant experimental studies. To address these limitations and to advance the current understanding toward two-phase regimes in high temperature Pb-based melts, the present work focuses on the design and assembly aspects of an electrical conductivity-based two-phase detection sensor array, utilizing high purity α-Al2O3 coatings with AlPO4 binder as electrical insulation layers. This paper discusses the design considerations, thermal analysis, systematic selection of structural/functional components along with preliminary results from the probe performance tests in very high temperature (600°C) static molten Pb column for real time detection of argon gas bubbles rising within the melt. Quantitative estimations of time-averaged void fraction, average bubble impaction frequency and average bubble residence time are presented from the preliminary experimental investigations.

Dress Code in Chinese High Schools: A Preliminary Design towards its Sociological Impacts

The dress code is enforced at several high schools in China, mandating that students adhere to certain guidelines. These guidelines prohibit the wearing of braces, skirts that are deemed too short, and anything that is considered attention-grabbing. It is intriguing to note that clothing codes often impose greater restrictions on women as compared to males. Certain educational institutions require their students to adhere to a dress code that mandates the wearing of complete ensembles daily. The independence of several pupils is constrained by intricate and stringent regulations, which also reinforce the notion of gender differentiation between boys and girls. Numerous attires exhibit a lack of comfort, hence impeding students' ability to effectively engage in learning and perform optimally. Individuals are often informed that these regulations are implemented to mitigate the impact of their attire on fellow members inside the institution, therefore potentially impeding their ability to engage in learning and professional activities. The objective of the rigorous experiment is to assess its efficacy. The occurrence of social desire bias may arise when both individuals involved in a trial possess an awareness of its proceedings. This phenomenon occurs when individuals provide responses that are widely embraced by society, but fail to accurately reflect their true beliefs and opinions. The Implicit Association Test (IAT) is used to ensure the validity of the experiment. By using this preliminary experimental design, further analyses, and investigations might use more dependable data to examine the whole of the matter.

Towards an optimized heat transfer process in vaporizing liquid microthrusters using pulsed heating control

The Institute for Microelectronics and Microsystems of the Italian National Research Council (Italy) has designed and fabricated a water-fed MEMS vaporizing liquid microthruster (VLM) in collaboration with the University of Salento (Italy) and KU Leuven (Belgium). Previous studies have demonstrated the device’s functioning and highlighted the presence of a strong thermoelectric-hydraulic coupling that severely affects the heating and propulsive efficiencies and reliability of the device. In this regard, the current work provides a preliminary experimental investigation of a pulsed heating system actively controlled by temperature using PI-D logic (proportional and integrative actions applied to the error; derivative action applied to the output). The overall performance assessment focuses on evaluating power consumption during steady-state operation and analyzing the dynamic response of the VLM undergoing such an actively controlled pulsed heating, which has been built using both manual and data-driven offline adaptive tuning of the PID parameters. Concerning the steady-state operation, results highlight a promising enhancement of the heating efficiency to values above 0.9. The dynamic response analysis shows that operating with a single set of fixed PID parameters is not feasible and that the manual tuning is a trial-and-error approach highly dependent on the operator’s experience, operating conditions, and reference temperature profile. Furthermore, shorter rise and response times require a higher proportional gain, and the overshoot experienced when crossing the saturation temperature cannot be avoided. In this paper, we show that the response of the data-driven adaptive controller solves these issues, exhibiting a reduced maximum settling time from around 59 s to less than 10 s, while the overshoot is avoided thanks to the temporal adjustment of the PID parameters.

Self-guided imagery rescripting for worry images: A preliminary experimental investigation.

Mental images of feared events are overactive and intrusive in generalized anxiety disorder (GAD). Imagery rescripting involves integration of positive or neutral imagery and corrective information into images to facilitate emotional processing, reduce imagery intrusions, and re-structure underlying schema. Yet only one known study has applied the technique to treatment of worry. The present study aimed firstto examine the relationship between trait worry and properties of future-oriented worry images, and secondto examine the efficacy of a self-guided imagery rescripting intervention in improving individuals' response to their worries. Participants recruited through Amazon Mechanical Turk (N = 365) identified their major worry and wrote the script of a worst-case scenario mental image. Participants were randomized to three conditions: re-writing the same worry image script (exposure), or writing scripts of either one or three positive alternative future-oriented images (rescripting conditions). In preliminary analyses, trait worry negatively predicted participants' ratings of worry images, including valence and ability to cope, and positively predicted distress, anticipated cost, and belief in their negative meaning. In experimental analyses, linear mixed-effects models revealed anxious response and cognitive appraisal of the threat were significantly lower among participants allocated to rescripting relative to exposure. There was no effect of rescripting type. This investigation demonstrated the impact of a future-oriented imagery rescripting task on anxiety and cognitive biases associated with real worries in an unselected sample. Results may contribute to the development of imagery rescripting interventions for GAD.

Detection of butterfly fractures of long bones through multi-slice computed tomography and micro-computed tomography

Motor-vehicle accidents often result in lower limb injuries with biosseous fractures.The present study aimed at comparing multi-slice computed tomography (MS-CT), micro-computed tomography (micro-CT) and external fractography for the analyses of experimentally produced biosseus leg fractures.Briefly, 48 human legs amputated for medical reasons were defleshed and then experimentally fractured using a 3-point dynamic bending model (70,6 J of impact energy at the middle of the anterior surface of the tibia) producing 38 biosseous and 10 mono-osseous fractures with a total of 86 fractured bones. External fractography detected 63 (73,2%) “butterfly” fractures (24 (27,9%) complete and 39 (45,3%) incomplete), 14 (16,3%) “oblique” fractures, 6 (7,0%) “comminuted” fractures and 3 (3,5%) “transverse” fractures. Forty-three (43) of the 48 included legs displayed at least one butterfly fracture located at the tibia or fibula. MS-CT correctly detected and classified 16 complete and 20 incomplete butterfly fractures, failing to properly classify 27 fractures; 19 of these misclassifications led to an interpretative error on the trauma direction (i.e., 16 incomplete butterfly fractures classified as oblique fractures and 3 incomplete butterfly fractures classified as transverse). Micro-CT correctly detected and classified 22 complete and 37 incomplete butterfly fractures, failing to properly classify 4 fractures; two of these misclassifications led to an interpretative error on the trauma direction (i.e., two incomplete butterfly fractures classified as oblique fractures).Although further studies evaluating a wider number of fractures and fracture patterns are required to drive any definitive conclusions, this preliminary experimental investigation showed that MS-CT and micro-CT represent useful tools for reconstructing the morphology of leg fractures and could be crucial for trauma analysis in the forensic context. MS-CT could be used as a screening tool, micro-CT as second level analysis and external/internal fractography as third level, confirmatory analysis.

Intrinsically thermally conductive polymers.

Here, we describe the design features that lead to intrinsically thermally conductive polymers. Though polymers are conventionally assumed to be thermal insulators (<0.3 W m-1 K-1), significant efforts by the thermal transport community have shown that polymers can be intrinsically thermally conductive (>1.0 W m-1 K-1). However, these findings have not yet driven comprehensive synthetic efforts to expose how different macromolecular features impact thermal conductivity. Preliminary theoretical and experimental investigations have revealed that high k polymers can be realized by enhancing the alignment, crystallinity, and intermolecular interactions. While a holistic mechanistic framework does not yet exist for thermal transport in polymeric materials, contemporary literature suggests that phonon-like heat carriers may be operative in macromolecules that meet the abovementioned criteria. In this review, we offer a perspective on how high thermal conductivity polymers can be systematically engineered from this understanding. Reports for several classes of macromolecules, including linear polymers, network polymers, liquid-crystalline polymers, and two-dimensional polymers substantiate the design principles we propose. Throughout this work, we offer opportunities for continued fundamental and technological development of polymers with high thermal conductivity.

Preliminary experimental investigation into the use of recycled fibres from textile waste for the improvement of embankments

Preliminary experimental investigation into the use of recycled fibres from textile waste for the improvement of embankments

Experimental Investigation of CECE Process to Recover Tritium and Deuterium from Low Tritiated/Deuterated Liquid Waste

A current concern of researchers from the Experimental Pilot Plant for Tritium and Deuterium Separation (PESTD) within the National R&D Institute for Cryogenics and Isotopic Technologies in Rm. Valcea is the solution of a combined electrolysis catalytic exchange (CECE) isotopic separation process that aims to be part of a new liquid waste decontamination technology. The experimental installation, defined as module M1100, has interfaces with the PESTD process and auxiliary systems and is placed within the PESTD area. The installation has its own automation and control system that allows for safe operation. Two operating modes are presented. The first mode is in “open-circuit” mode to evaluate the individual separation performances of the two technological processes, water electrolysis and water-hydrogen catalytic isotopic exchange, respectively. The second mode is in “closed loop,” which corresponds to the CECE isotopic separation process where the tritium/deuterium are concentrated in the water within the electrolyzer. The preliminary experimental investigations were performed with low-concentrated tritiated water (HTO; ~100 Bq/l] in order to have a reduced degree of contamination as the concentration of the processed water was increased (~1000 Bq/l). The evaluation of the separation performances was made by comparing correlations from direct measurements with the calculated ones provided by the software developed for the CECE isotopic separation process in the open-circuit operating mode. For the closed-loop operation mode, the data provided by the calculation program for the representation of the nonstationary CECE isotopic separation regime were compared with the measured data. The preliminary results show a good correlation between the measured and the calculated data considering these experiments were carried out mainly in order to improve the operating performance.

Preliminary experimental investigation on long-term fracture conductivity for evaluating the feasibility and efficiency of fracturing operation in offshore hydrate-bearing sediments

Gas hydrate is undoubtedly an essential resource for sufficient energy supply (natural gas) in the near future. Unfortunately, low production efficiency limits its effective development and utilization. Hydraulic fracturing is a common and effective engineering measure to stimulate oil and gas reservoirs, as well as enhance oil recovery. However, its feasibility for clayey silt hydrate-bearing sediments is unclear now. What is more, there is no scientific basis for determining or assuming the value of fracture conductivity used in productivity prediction. In the present work, factors affecting conductivity of fractures in hydrate-bearing sediments were explored first. The experimental results showed that the conductivity of fracture in hydrate-bearing sediments was lower than 50 μm2·cm. Besides, it was found that the increase of proppant size, proppant concentration and hydrate saturation can improve the fracture conductivity. However, to achieve a similar effect, the closure pressure needs to be reduced appropriately. Based on these experiment results, the multi-factor influence model of fracture conductivity in hydrate-bearing sediments was developed. The conductivity profile at site SH2 in the northern South China Sea was then obtained. Finally, feasibility and efficiency evaluation of fracturing operation in hydrate reservoir was numerically conducted. The investigation results reveals that fracturing operation can greatly promote hydrate dissociation and gas production in hydrate development process. In addition, the importance of accurately determining fracture conductivity in productivity prediction of hydrate reservoir was also explored. It was found that gas production is only 12.11 × 108 m3 when fracture conductivity is 5.0 μm2·cm. However, it was as high as 22.82 × 108 m3 when fracture conductivity is 40 μm2·cm, which is 1.88 times that of the former case. The present work provides new perspective for design and optimization of fracturing operation in hydrate-baring sediments.

Design of a Ventilated Façade Integrating a Luminescent Solar Concentrator Photovoltaic Panel

The increasing trend towards decarbonization requires the reduction of the environmental impact of the building sector that currently accounts for approximately 40% of the total CO2 emissions of European countries. Even though Luminescent Solar Concentrator (LSC) panels could be a very promising technology to be installed in urban environments, there is still little implementation of LSC panels in building façades. Here, the realization of a Ventilated Façade (VF) integrating an LSC device as an external pane is presented and a preliminary numerical and experimental investigation is used to evaluate the interaction between the different structure components. Thanks to the realization of a dedicated mock-up finite element method, models are calibrated and validated against experimental measurements, showing a good correspondence between simulated and measured data. Moreover, the electrical characterization of the LSC panel confirms that large area devices can be used as an external skin of VF, reporting a photovoltaic efficiency of 0.5%. The system’s thermal and optical properties (estimated thanks to the software COMSOL Multiphysics) encourage the continuation of the research by considering different technologies for the VF internal skin, by scaling up the case study, and by running the simulation of an entire building considering winter and summer energy demands.

Ferroelectret Polypropylene Foam-Based Piezoelectric Energy Harvester for Different Seismic Mass Conditions

Energy harvesting technologies and material science has made it possible to tap into the abundant amount of surrounding vibrational energy to efficiently convert it into useable energy providing power to portable electronics and IoT devices. Recent investigations show that the piezoelectric effect is created in cellular polymers called ferroelectrets. These cellular-compliant polymers with polarized pores have a piezoelectric response to generate electrical energy when subjected to mechanical strain or surrounding vibration. It is found that there is a significant difference between ferroelectret polarized cellular polypropylene foam and traditional piezoelectric polymers such as polyvinylidene fluoride (PVDF). The former has approximately ten times higher piezoelectric coefficient than the latter. This means that with an acceleration of 9.81 m/s2 force on this material, ferroelectrets generate up to 39 (µW/g/mm3) power output. Designing a polypropylene-based piezoelectric energy harvester based on the d33 mode of vibration can be challenging due to several factors, as it requires balancing multiple factors such as mechanical stability, piezoelectric response, circuit topology, electrode size, spacing, placement relative to the piezoelectric material, and so on. This paper proposes the preliminary experimental investigation of ferroelectret cellular polypropylene foam in harvesting performance. Suggestions of different approaches for the structural design of energy harvesters are provided. The vibration-dependent response and generated output are examined concerning pulse or sinusoidal input excitation. The voltage generated for both excitations is compared and suggestions are provided regarding the suitable kind of excitation for the chosen ferroelectret material. Finally, conclusions and prospects for ferroelectret materials used in energy-harvesting applications are given.

Synthesis and Photocatalytic Properties of Four Coordination Compounds Constructed from Two Benzimidazole-Based Asymmetric Polyazocyclic Ligands.

In this paper, two benzimidazole derivative ligands were obtained using o-phenylenediamine and n-pyridine formaldehyde (n = 3, 4) by amine-aldol condensation reactions, which were reacted with selected inorganic metal salts by ambient temperature volatilization method to give compounds 1-4: {[(L1)6]·[Cu8I8]} (1), {[L1]·[CuBr]·H2O} (2), {[L2]·[CuBr]}n(3), and {[(L2)4]·[Cu4I4]} (4). They were characterized by IR, UV-Vis absorption spectroscopy, thermogravimetric analysis, and single crystal X-ray analysis. Simultaneously, compounds 1-4 were found to possess photocatalytic degradation of ciprofloxacin (CIP) by preliminary experimental investigations.

Pressure-velocity measurements of a small automotive fan at different working conditions. A noise generation perspective.

Although noise from large fans has been extensively studied by the scientific community, few experimental studies have been performed on small-scale fans, where aerodynamic effects due to low Reynolds numbers needs be taken into account. For this reason, some preliminary experimental investigations have been carried out on cooling fans for automotive applications. The experimental campaign has been focused on the characterization of the flow outlet first, using a static Pitot on a 5.5-inch five-bladed fan, with and without its protective grid. After this preliminary phase, simultaneous measurements of velocity with hot-wire anemometry (HWA) and pressure fluctuations with microphones have been also carried out, the HWA probe being located downstream and two microphones positioned in the nearfield and far-field of the fan. The fan has been also studied at different working conditions, varying the rotational speed and applying specific fine grids at the intake, in order to well reproduce the presence of the cooler. Analyses in the time and frequency domain have been performed on the measured data, including cross-correlation between pressure and velocity signals, in order to find the main driving mechanisms that are related to the noise generation.

Push-out performance of inclined screw shear connectors used in nail-laminated timber-concrete composite

Self-tapping screws (STSs) have been used as shear connectors in various timber-concrete composites, while research focused on the push-out performance of STS connectors used in nail-laminated timber-concrete composite (NLTCC) is limited. This paper presents the experimental investigation and numerical parametric analysis on the push-out performance of inclined screw shear connectors used in NLTCC. There were 30 specimens with the same configuration tested in this project. The preliminary experimental investigation indicates that the STS shear connectors, with a nominal diameter of 11 mm and a penetration length of 260 mm, can achieve a shear capacity and slip modulus of 32.5 kN and 6.92 kN/mm, respectively. The main failure modes include concrete cracking, screw two-hinge yielding and localized nail-laminated timber (NLT) embedment failure. A numerical model was then developed and verified using the test results to predict the behavior of this STS connectors. A parametric analysis, using the verified model, was carried out to quantify the influence of screw diameter and penetration length on its push-out performance. Analysis results show the push-out performance is in positive and linear correlation with the screw nominal diameter. A positive but nonlinear correlation is noticed between the screw penetration length into NLT and its push-out performance. This is because the controlling failure mode was changed from two-hinge yielding of STS to localized NLT embedment when penetration length was overly increased.

PRELIMINARY INVESTIGATION ON THE EFFECT OF CUTTING PARAMETERS ON SURFACE ROUGHNESS AND FLATNESS IN DRY MILLING OF PMMA

Polymethylmethacrylate (PMMA) also known as Plexiglass is a commonly used material for many applications, especially in medical industry. In some application, PMMA parts may be also used as molds for enabling fabrication of final products. Some of these parts are manufactured by injection molding, but in many cases mechanical machining of some surfaces is still required. The cutting of PMMA requires a previous optimization of the cutting parameters combination (feed rate and spindle speed). If this optimization is not carried out, the problems encountered may refer to cutting debris or material melting during machining and, consequently, the material attaches to the tool cutting edge. This will result in a surface with very poor quality, in terms of aspect and surface roughness. This paper reports on the preliminary experimental investigation of cutting parameters on the surface roughness and flatness error in dry milling of PMMA. The cutting experiments were conducted on EMCO MILL 55 CNC drilling and milling machine. The design of experiment (DOE) consists in L27 (33) design, meaning a three factorial experimental plan (3 factors on 3 levels). The cutting parameters, respectively depth of cut, feed rate and spindle speed are taken as inputs and surface roughness and flatness are taken as outputs. The surface flatness was measured with TESA Micro-Hite coordinate measuring machine. Analysis of variance (ANOVA) was adopted to identify the statistical influence of each input parameter and combination of input parameters on surface roughness. From the preliminary results, it can be observed that optimum regime is a combination of low feed rate, low depth of cut and high spindle speed. Moreover, an artificial neural model is proposed for prediction of surface roughness and flatness considering the depth of cut, feed rate and spindle speed as input variables. This approach aims to reveal the possibility of predicting the output parameters using neural network modelling, that can be further used to optimize the cutting regime.

Preliminary Experimental Investigation of an -Band Low Magnetic Field Coaxial Relativistic Klystron Oscillator

An <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> -band coaxial relativistic klystron oscillator (RKO) is proposed to improve the beam–wave interaction efficiency in the low magnetic field and low impedance. The device adopts a four-gap modulation cavity to increase the fundamental current, and a three-gap extraction cavity is used to improve the microwave extraction capability. The simulation results show that when the guiding magnetic field and impedance are 0.55 T and 40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> , respectively, the output microwave power is 3.65 GW and the corresponding efficiency is 40%. Subsequently, a preliminary experimental investigation was carried out to verify the feasibility of this technical route. In the experiment, the output microwave with a power of 2.3 GW, a pulsewidth of 69 ns, and a center frequency of 9.39 GHz was generated when the magnetic field and impedance are 0.62 T and 41 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> , respectively. Moreover, the explosive electron emission model of the extraction cavity is established, and the simulation results show that the explosive electron emission generated by the radio frequency (RF) breakdown at the extraction cavity is the main reason for the difference between the experimental and simulated microwave power.

A preliminary experimental investigation on the biotribocorrosion of a metal-on-polyethylene hip prosthesis in a hip simulator

Corrosion at the taper/trunnion interface of total hip replacement (THR) often results in severe complications. However, the underlying mechanisms of biotribocorrosion at the taper/trunnion interface during the long-term walking gait cycles remain to be fully understood. In this study, a hip joint simulator was therefore instrumented with an electrochemical cell for in-situ monitoring of the tribocorrosion evolution in a metal-on-polyethylene (MoP) THR during a typical long-term walking gait. In addition, the biotribocorrosion mechanism was investigated via surface and chemical characterizations. The experimental results confirmed that the taper/trunnion interface dominated the contemporary MoP hip joint corrosion. Three cyclic variations in the open circuit potential (OCP) were observed throughout the long-term electrochemical measurements, attributed to the formation and disruption of the adsorbed protein layer. The corrosion exhibited an initial increase at each period, peaking at approximately 0.125 million cycles, followed by a subsequent gradual reduction. Surface and chemical analyses revealed the formation of a tribochemical reaction layer (tribolayer) on the worn surface of the taper/trunnion interface. The surface/chemical characterizations and the electrochemical measurements indicated that the adhesion force of the adsorbed protein layer was weaker than that of the tribolayer. In contrast, the opposite was true for the corrosion resistance. Based on the observations from this study, the tribocorrosion mechanism of the taper/trunnion interface under the long-term walking gait cycles is deduced.

Development of a novel magnet system for a 1 kg Planck balance

Abstract The following paper presents the development of a novel magnet system for use in a 1 kg Planck balance. For this purpose, several preliminary theoretical and experimental investigations were carried out and an optimized prototype magnetic system was modeled, designed and built based on the results. Initial measurements showed that the magnet system with an outer diameter of 104mm and a height of 50mm achieved a constant average value of 85.25NA−1 at a range of motion of ±0.6mm.