Actual Setup Research Articles

Soft Sensing for On-Line Fault Detection of Ammonium Sensors in Water Resource Recovery Facilities.

The increasing demand for online sensors applied to advanced control strategies in water resource recovery facilities has resulted in the increasing investigation of fault-detection methods to improve the reliability of sensors installed in harsh environments. The study herein focuses on the fault detection of ammonium sensors, especially for effluent monitoring, given their potential in ammonium-based aeration control applications. An artificial neural network model was built to predict the ammonium content in the effluent by employing the information from five other sensors installed in the activated sludge tank: NH4+, pH, ORP, DO, and TSS. The residual between the model prediction and the effluent ammonium sensor signal was utilized in a fault-detection mechanism based on principal component analysis and Shewhart monitoring charts. In contrast to previous studies, the present work utilizes typical faults collected from a 1 year historic dataset of an actual sensor setup. Treatment process anomalies, calibration bias faults, and fouling drifts were the most common issues identified from the historic dataset, and they were promptly identified by the proposed fault-detection methodology. Once a fault is detected, the model prediction can be actively used in place of the sensor for process control without affecting the treatment process by utilizing faulty datasets.

Numerical study on the supersonic near-wake flow structures of a cylinder at an angle of attack

The supersonic near-wake flow experiment conducted by Dutton on a cylinder with 10 degrees angle of attack was studied numerically with Delayed Detached Eddy Simulation (DDES) method. The wind tunnel test section were included in the geometry model to examine if its omission led to the unsuccessful prediction of several important flow features in previous studies. Flow structures were compared to experiment measurements, Gaitonde's k-ε model results and our previous Monotonically Integrated Large Eddy Simulation (MILES) results. It was revealed that with present geometry model and numerical method, good agreements with wind tunnel experiment result were obtained, including the wave structures, density fields and velocity fields. In particular, the inclusion of wind tunnel test section wall in geometry model reproduces the finite area nozzle exit flow and the expansion wave behind the recirculation zone in the actual experiment setup, which lead to correct prediction of the position of maximum streamwise velocity point. The present simulation also reproduced the uniform pressure profile and value observed in the experiment and the deviation between computation and experiment was within 10%. The flow field data obtained was further analyzed to investigate the vortex surface shape and recirculation region shape in near wake flow with non-zero angle of attack and significant differences were found compared to the zero angle of attack case. The vortex surfaces show a non-axisymmetric slitting movement in the near wake region, which gives an explanation to the non-circular density contour pattern on streamwise flow field slices. The recirculation region shape was identified with zero isosurface of streamwise velocity and was found to be of complex three-dimensional shape with maximum length beside the symmetry plane and a local minimum at windward side of the symmetry plane, which is significantly different from that of zero angle of attack case. The observation that the length of the recirculation zone was greatly reduced on the symmetry plane at non-zero angle of attack in previous study is due to the aforementioned local minimum on the symmetry plane. The reduction of recirculation length is much less if we consider the three-dimensional shape of the region.

Method for environmental noise estimation via injection tests for ground-based gravitational wave detectors

Environmental noise is one of the critical issues for the observation of gravitational waves, but is difficult to predict in advance. Therefore, to evaluate the adverse impact of environmental noise on the detector sensitivity, understanding the detector response to the environmental noise in actual setup is crucial, for both the observation and future upgrades. In this paper, we introduce and verify a new method of the environmental noise injection test based on the post-observation commissioning of KAGRA. This new method (response function model) includes the frequency conversion and nonlinearity of power, which are the effects that are not considered in the current model (coupling function model) used in LIGO and Virgo. We also confirmed the validity of our method by applying it to an environmental noise-enriched dataset and successfully reproducing them.

Explainable machine learning determines effects on the sound absorption coefficient measured in the impedance tube.

Measurements of acoustic properties of sound absorbing materials in impedance tubes show poor reproducibility, which was demonstrated in round robin tests. The impedance tube measurements are standardized but lack precise definitions of the actual measurement setup, specimen preparation, and other factors that introduce uncertainty in practice. In this paper, machine learning models identify those factors that mostly affect the sound absorption coefficient from a large data set of more than 3000 absorption spectra measured in one impedance tube. The specimens are manufactured from one polyurethane foam, and different cutting technologies, different operators, different specimen diameters, different specimen thicknesses, and two different approaches to mount the specimens in the impedance tube are considered. Explainable machine learning techniques allow the identification and quantification of the most influential factors and, furthermore, the frequency ranges that are the most affected by the choice of these setup factors. The results indicate that besides the specimen thickness, also the operator affects the absorption coefficient by a directional and non-random relationship. Hence, it needs to be controlled carefully. The method proves to be a promising pathway for knowledge discovery from acoustic measurement data using explainability approaches for machine learning models.

Load capacity of occlusal veneers of different restorative CAD/CAM materials under lateral static loading

ObjectiveThe aim of this in vitro study was to analyze the failure of occlusal veneers made of three different restorative CAD/CAM materials under lateral static loading. Materials and methodsSixty standardized semi-anatomical occlusal veneers were fabricated on natural lower molars from three different CAD/CAM materials: hybrid ceramic (Vita Enamic), lithium disilicate (IPS e. max CAD) and translucent zirconia (Bruxzir). The specimens were mechanically loaded by a custom-made device attached to a universal testing machine (MTS 858 Mini Bionix II, MN, USA). Static lateral loading was applied on the buccal cusp of the occlusal veneer until failure. Failure loads were recorded, and the types of failure noted for each group. 3D finite element (FE) models simulating the actual test set-up were further employed to evaluate the stresses within the tooth-restoration complex to help interpret the experimental results. ResultsOcclusal veneers made from zirconia recorded a significantly higher mean failure load (843.1 ± 141.5 N) than specimens of the other two materials (p < 0.05). There was no statistically significant difference between the lithium disilicate (493.21 ± 102.24 N) and the hybrid ceramic (499.6 ± 123.1 N) groups (p = 0.863). 74% of the hybrid ceramic and 84% of the lithium disilicate specimens showed veneer fracture, whereas 78% of the zirconia veneers showed debonding. Comparison of the FE-predicted stresses with the different failure strengths corroborated with the experimental results. ConclusionLateral loading caused failure of occlusal veneers at loads significantly lower than those reported for axial loading. Among the materials tested, zirconia veneers showed the highest resistance to failure, with the main failure mode being debonding under lateral loading. The other two material groups failed mainly by veneer fracture at lower loads.

Impact Assessment of Workers on Short Term Exposure within the Recommended Permissible Noise Exposure Limit (85 - 90 dBA)

As occupational safety and health become a focus in developing third world countries like the Philippines, research, test, and measurement were given investment to improve the status of health and safety. This study sought to determine the effect of 85 to 90 dBA exposure to workers in a controlled environment. Age, work experience, and gender were also assessed for possible correlation on the performance while exposed to different noise levels. One at a time, workers proceed to the audio isolation booth with observation window, controlled temperature, relative humidity, lightings, and noise level to complete three tasks namely abstract and logic test for 60 minutes, simplified mathematics test for 30 minutes, and set-up activity for 15 minutes. Each worker has to complete six sets of tests with a different continuous noise exposure level of 85 to 90 dBA. Observations of incidents inside the booth were also noted in the results. Workers perform best with a mean of 72% for 85 dBA in declining pattern to 38% performance for 90 dBA noise exposure for the Abstract and logic test. The same pattern was observed for a simplified mathematics test with the mean of 86.80% for 85 dB dropping to 64% for 90 dBA exposure while the actual set-up activity obtained 65% mean for worker completion when exposed to 85 dBA sliding to 35% for 90 dBA. In addition, the tallied health and safety issues raised by the workers and notes by the observers resulted in an increasing trend from 5% for 85 dBA, 11% for 86 to 88 dBA, 26% for 89 dBA, and 37% for 90 dBA. On the other hand, Pearson correlation confirms the negative correlation of noise level to abstract and logic, simple mathematics, and practical assembly set-up while noise level has a positive correlation with Health and Safety issues. Overall, if the 90 dBA noise level or higher is maintained in a specific workplace without any controls or interventions to lower down the noise level, the productivity and efficiency of workers will be low while their health and safety might be at risk.

Impact of Gaussian uncertainty assumptions on probabilistic optimization in particle therapy

Range and setup uncertainties in charged particle therapy may induce a discrepancy between the planned and the delivered dose. Countermeasures based on probabilistic (stochastic) optimization usually assume a Gaussian probability density to model the underlying range and setup error. While this standard assumption is generally taken for granted, this study explicitly investigates the dosimetric consequences if the actual range and setup errors obey a different probability density function (PDF) over the course of treatment to the one used during the probabilistic treatment plan optimization. Discrete random sampling was performed for conventionally and probabilistically optimized proton and carbon ion treatment plans utilizing various PDFs that modeled the setup and range error. This method allowed us to assess the treatment plan robustness against different PDFs of conventional and probabilistic plans, which both explicitly assume Gaussian uncertainties. The induced uncertainty in dose was quantified by estimating the expectation value and standard deviation of the RBE-weighted dose for each PDF on the basis of 2500-5000 random dose samples. Probabilistic dose metrics and standard deviation volume histograms were computed to quantify treatment plan robustness of both optimization approaches. It was shown that the classical planning target volume margin extension concept did not compensate the influence of range and setup errors and consequently resulted in a non-negligible average standard deviation in dose of 7.3% throughout the clinical target volume (CTV). In contrast, probabilistic optimization on normally distributed errors yielded treatment plans that not only entailed a lower standard deviation against normally distributed errors accounted for during optimization, but also lower standard deviations for other symmetric PDFs. It was shown that the impact of an incorrect probability distribution assumption is of lower importance after probabilistic optimization as the average uncertainty in the CTV drops to 3.9%. Probabilistic optimization is an effective tool to create robust particle treatment plans. Normally distributed range and setup error assumptions for probabilistic optimization are a reasonable first approximation and yield treatment plans that are also robust against other PDFs.

Confinement versus interface bound states in spin-orbit coupled nanowires

Semiconductor nanowires with strong Rashba spin-orbit coupling are currently on the spotlight of several research fields such as spintronics, topological materials and quantum computation. While most theoretical models assume an infinitely long nanowire, in actual experimental setups the nanowire has a finite length, is contacted to metallic electrodes and is partly covered by gates. By taking these effects into account through an inhomogeneous spin-orbit coupling profile, we show that in general two types of bound states arise in the nanowire, namely confinement bound states and interface bound states. The appearance of confinement bound states, related to the finite length of the nanowire, is favoured by a mismatch of the bulk band bottoms characterizing the lead and the nanowire, and occurs even in the absence of magnetic field. In contrast, an interface bound states may only appear if a magnetic field applied perpendicularly to the spin-orbit field direction overcomes a critical value, and is favoured by an alignment of the band bottoms of the two regions across the interface. We describe in details the emergence of these two types of bound states, pointing out their differences. Furthermore, we show that when a nanowire portion is covered by a gate the application of a magnetic field can change the nature of the electronic ground state from a confinement to an interface bound state, determining a redistribution of the electron charge.

Are models of local hidden variables for the singlet polarization state necessarily constrained by the Bell inequality?

The Bell inequality is thought to be a common constraint shared by all models of local hidden variables that aim to describe the entangled states of two qubits. Since the inequality is violated by the quantum mechanical description of these states, it purportedly allows distinguishing in an experimentally testable way the predictions of quantum mechanics from those of models of local hidden variables and, ultimately, ruling the latter out. In this paper, we show, however, that the models of local hidden variables constrained by the Bell inequality all share a subtle, though crucial, feature that is not required by fundamental physical principles and, hence, it might not be fulfilled in the actual experimental setup that tests the inequality. Indeed, the disputed feature neither can be properly implemented within the standard framework of quantum mechanics and it is even at odds with the fundamental principle of relativity. Namely, the proof of the inequality requires the existence of a preferred absolute frame of reference (supposedly provided by the lab) with respect to which the hidden properties of the entangled particles and the orientations of each one of the measurement devices that test them can be independently defined through a long sequence of realizations of the experiment. We notice, however, that while the relative orientation between the two measurement devices is a properly defined physical magnitude in every single realization of the experiment, their global rigid orientation with respect to a lab frame is a spurious gauge degree of freedom. Following this observation, we were able to explicitly build a model of local hidden variables that does not share the disputed feature and, hence, it is able to reproduce the predictions of quantum mechanics for the entangled states of two qubits.

Influence of direct electric current on wetting behavior during brazing

The wetting behavior of liquid metals is of great importance for many processes. For brazing, however, a targeted modification beyond the adjustment of conventional process parameters or the actual set-up was not possible in the past. Therefore, the effect of direct electric current along the surface of a steel substrate on the wetting behavior and the formation of the spreading pattern of an industrial nickel-based filler metal was investigated at a temperature above T = 1000 °C in a vacuum brazing furnace. By applying direct current up to I = 60 A the wetted surface area could be increased and the spreading of the molten filler metal could be controlled in dependence of the polarity of the electric current. The electric component of the Lorentz force is supposed to be feasible reasons for the observed dependence of the electrical polarity on the filler metal spreading direction. To evaluate the influence of the electric current on the phase formation subsequent selective electron microscope analyses of the spreading pattern were carried out.

Peanut production through innovative water management strategies

Background/Objectives: A study on enhancing peanut production through drip irrigation (DI) technology was conducted to increase the productivity and profitability of peanut production in the Ilocos region, Philippines. It sought to develop irrigation management strategies suitable for peanut. Methods/Statistical analysis: Decision Support System for Agrotechnology Transfer (DSSAT) simulation was done, and field validation was conducted to achieve the objectives. The simulation activity led to the determination of the top three promising drip irrigation management schemes suitable for peanut production, which were then field validated through actual field set-up in three different locations. The best scheme (DI S9 410mm) was then pilot-tested at the farmers\' field and compared with Farmers\' Practice (FP) d using t-test. Findings: Using the DI scheme, dry pod yield was increased from 1.59Tha-1to 2.09Tha-1 or 31.45% increase as compared to the farmer\'s practice. This result is a little higher than the target increase in yield of 30%. Findings indicate that the DI is a much better method than FP, increasing the dry pod yield to as much as 70.21% during the dry season. Yield increase could be attributed to more even application of water and less water stress. On the other hand, water productivity was only increased by around 16% due to farmers\' limited water application. In terms of seed quality based on seed size, DI and FP are comparable. Results the economic analysis showed that yield of peanut under DI were higher by about 0.84Tha-1 to 1.16Tha-1 as compared to FP with a Return of Investment (ROI) of 0.25. In the long run, the profitability of DI could be improved through water productivity and yield improvements. Water savings was not a factor in profitability due to under-irrigation by farmers. Novelty/Applications: The use of DI technology with the developed irrigation scheme substantially contributed to the goal of increasing the productivity of and profitability of peanut. It is especially useful for areas with limited water supply for irrigation. Keywords: Drip irrigation; peanut; water productivity; water savings; DSSAT simulation

The Robust Routing Protocol with Authentication for Wireless Adhoc Networks

The adhoc networks are the platforms formed for specific reason to attain a specific purpose. It is a communication strategy followed by the wireless devices when or while the actual communication setup is not possible. Any portable device communicating in the wireless medium in a decentralized manner is termed to be a wireless adhoc network. One such device is the wireless-sensors that imitate the aforementioned procedures to send the information from the source to the target falls under the category of the wireless adhoc network, as it communicates through the air in a wireless medium. The rapid proliferation of sensors and growing demand for applications and services from the network formed using such wireless-sensors generate unrivaled appeals for routing data packets on infrastructure of the network formed using the wireless-sensors. Such sensors lays as the fundamental devices in a wide range application and are even more predominant in the internet of things paradigm. Numerous of such devices are used in the internet of things to gather enormous amount of data from a broad range of applications. The sensors used in the internet of thing usually performs the sensed data transmission to the gateway-nodes through the public channel that are insecure for conversing the confidential data. So the routing with authentication becomes essential, to make the routing robust and long lasting it is necessary to develop a light weight authentication scheme that does not consume too much of the energy of the network of the wireless-sensors. To handle this problem the paper concatenates the unique key generation technique the mid-square (Mid-S) with the Beziers curve based authentication (UKHA) to secure and authenticate the routing between the wireless-sensor networks framed in adhoc manner and the gate way nodes of the internet of things platform. The proposed protocol for routing is develop in the MATLAB and simulated in it to manifest the proficiency of the developed protocol on the terms of the energy consumption, packet deliver rate, percentage of losses incurred and running time.

Seeking frequent episodes in baseline data of In-Situ Decommissioning (ISD) Sensor Network Test Bed with temporal data mining tools

Savannah River National Laboratory (SRNL) has established an In-Situ Decommissioning (ISD) Sensor Network Test Bed—a unique, small scale, and configurable environment— for the assessment of prospective sensors on actual ISD system at minimal cost. The temporal data mining (TDM) technique can be employed to process the extensive data collected by the ISD sensors well because these data are time-specific, age-specific, and development stage-specific. This paper analyzed the baseline data collected by ISD Sensor Network Test Bed in recent years with the assistant of TDM algorithms to work out frequency episodes in the event stream. The results have confirmed that TDM techniques are effective tools to validate ISD performance, and the frequent episodes found in the data stream not only showed the daily cycle of the sensor responses, but also established the response sequences of different types of sensors, which was verified by the actual experimental setup. Some abnormal patterns may have the potential for prediction of system failures.

A novel multi-brand robotic software interface for industrial additive manufacturing cells

A novel multi-brand robotic software interface for industrial additive manufacturing cells

Dynamic model for using casterboard by a humanoid robot

ABSTRACTThe efficacy of traveling and movement is substantially enhanced by the use of wheel mechanisms, particularly when compared to bipedal locomotion. Humanoid locomotion can also be extended using appropriate tools. In this study, we focus on the casterboard as a tool that facilitates traveling, because it has comparatively high portability, and the rider can move forward without pushing off the ground. We present a dynamic model for the use of the casterboard in a humanoid robot. Given that the ankles and waist of the rider play a key role in traveling using the casterboard, the angles of those joints are utilized as the input of the proposed model. A simplified small-scale robot is used to determine essential elements, and a modified casterboard is employed to eliminate the risk of falling without loss of its unique properties, for verification of the dynamic model. Using simulations and experiments, it is demonstrated that the dynamic model effectively emulates the behavior of the actual setup with respect to forward movement and turning. The model serves as the basis for the planning of a reference trajectory using the casterboard.

Data-Centric Communication Framework for Multicast IEC 61850 Routable GOOSE Messages over the WAN in Modern Power Systems

In this paper, a data-centric communication framework is proposed for multicast routable generic object-oriented substation event (GOOSE) messages (MRGM) over the wide area network (WAN) for effective substation-to-substation (SS2SS) and substation to control center (SS2CC) communications. In this structure, the IEC 61850 GOOSE message is transmitted over the WAN using the data distribution service (DDS) as a fast, reliable, and secure data-centric communication middleware. The main feature of this framework is its multicast capability, where several authorized subscribers can receive a published message simultaneously. This can significantly improve the system monitoring and control of the protection systems in modern smart grids, where intelligent schemes can be applied. The effectiveness of the proposed platform, in terms of total end-to-end delay between participants, is evaluated through experimental results obtained from the actual hardware-based test setup developed at the Florida International University (FIU) smart grid testbed. The results demonstrate that the latency between sending and receiving a GOOSE message among participants is within its maximum time span defined by the IEC 61850-90-5 working group for communications over the WAN.

Trueness and precision of intraoral scanners in the maxillary dental arch: an in vivo analysis

Intraoral three-dimensional imaging has gained great interest in dentistry as a mean to generate risk-free imprints of the oral cavity. Accurate intraoral models facilitate proper diagnosis, growth assessment, outcome evaluation, and 3D printing applications. Here, in an actual clinical setup on 12 subjects, we evaluate the trueness and precision of two widely used intraoral scanners (TRIOS 3, 3Shape and CS 3600, Carestream), using an industrial scanner (Artec Space Spider) as a reference. Surface based matching was implemented using the iterative closest point algorithm (ICP). Trueness of the intraoral scans was analyzed by measuring their distance from the reference scan, in the upper buccal front area. Precision was tested through the distance of repeated scans regarding the whole dental arch, following superimpositions in the buccal front and in the whole dental arch area. TRIOS 3 displayed slightly higher precision (approximately 10 μm) compared to CS 3600, only after superimposition on the whole dental arch (p < 0.05). Both intraoral scanners showed good performance and comparable trueness (median: 0.0154 mm; p> 0.05). However, in individual cases and in various, not spatially defined areas, higher imprecision was evident. Thus, the intraoral scanners’ appropriateness for highly demanding, spatially extended clinical applications remains questionable.

Simulation and Experimental Substantiation of Beam Deflection under Guided End Conditions

This paper studies the nonlinear deflection characteristics of a rectangular cross sectional beam with guided support conditions. In this study two different end conditions namely guided – guided and guided – simply supported have been examined. Beams made with two dissimilar materials for instance, aluminum and steel have been considered for this study. Different loading conditions namely point load and the amalgamation of uniformly distributed load and point load have been taken into account in this study. The nonlinear response of a beam under static loading condition is influenced by various parameters like sectional properties of the beam, material, loading and boundary conditions etc. A separate loading fixture was fabricated using steel to apply the load (Point load and uniformly distributed load). The loading fixture was validated by performing an experimental measurement of the deflection under various loading conditions on a simply supported beam. The corresponding theoretical displacement values were calculated using the findings in literature and compared with test results .Both the results were found matching with each other with an average variation of just 10%. Based on this validation lesson, the loading fixture was incorporated in the actual study. Displacement values from the nonlinear static analysis were predicted using Finite Element Method and correlation was made with the experimental values for the actual beam setup. Close correlation among the numerical and physical test results was achieved and the maximum error was 8%.

A feasibility study of CO2‐based solar‐assisted Rankine cycle: a comparative case study for Isparta, Turkey

AbstractIn this study, a feasibility analysis of a solar‐assisted transcritical Rankine cycle working with carbon dioxide (CO2) is performed for Isparta, Turkey, in comparison with Kyoto, Japan, conditions. For the analyses, the characteristics of the system are adapted from the actual experimental research conducted at Doshisha University, Kyoto, Japan. In order to evaluate the performance of the CO2‐based integrated system, a mathematical model is established for the evacuated solar collectors. Energy and exergy analyses are carried out using the solar energy data of both cities. According to the simulation results, the average turbine power capacities are determined as 0.415 and 0.396 kW, while the average heat recovery capacities are calculated as 2.10 and 1.89 kW for Isparta and Kyoto, respectively. The yearly electricity generation for Isparta conditions is found to be about 40% higher than the Kyoto conditions with 1138.09 kWh. The results of second law analyses are showed that the highest exergy destruction rate occurs in August for Isparta conditions with 8.18 kW due to the higher solar radiation rates. From the results, it appears that the CO2‐based next‐generation solar‐assisted power and heat generation system can be established and utilized in Isparta more effectively. The future research should, therefore, concentrate on moving the actual experimental setup to Isparta for field test experiments. © 2019 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Residence Time Distribution-Based Analysis of an Industrial-Scale Biogas Fermenter

Residence Time Distribution (RTD) measurement-based analysis of mixing conditions on an industrial-scale (13,000) anaerobic digester of pressed sugar-beet slices at Kaposvar Sugar Factory of Magyar Cukor Zrt. was studied. The lithium salt tracing technique was applied, while the quantity of the lithium chloride tracer and the sampling of the effluent were designed by a preliminarily studied simulation model of mixing. The lithium concentration at the outlet was analysed by Inductively coupled plasma–optical emission spectroscopy (ICP-OES). Taking into account the geometrical arrangement, the biogas flow produced and the cyclically changing recycle flow, various mixing models were generated with different compartmentalization and flow structures by applying the method of Programmable Process Structures. The simulation-based approximate identification of the mixing model was accomplished by a heuristic approach that took into consideration multiple structures with changing mixing flows. A model with an advantageously small number of compartments and parameters was sought which satisfies the measured RTD. The results suggest the intensive mixing of upper levels with a poorly mixed lower level, which contributes to the long tail in the RTD. The actual set-up supports a good horizontal distribution of the sugar-beet slices and the microbial biomass, while the limited degree of vertical mixing helps to avoid the elutriation of the useful microbiome. The suggested mixing model will be combined with the formerly elaborated model involving 9 bacterial groups.