Instantaneous Values Research Articles

Route optimization for vessels in ice: Investigating operational implications of the carbon intensity indicator regulation

The International Maritime Organization has adopted the Carbon Intensity Indicator (CII) regulation to promote decarbonization of shipping operations. The CII regulation includes specific treatment for vessels sailing in ice, which allows the time spent in ice, the associated emissions and transport work, to be excluded from the reported annual CII. The current study investigates the implications and possible side effects of this exemption in all ice-covered waters. A proposed model integrates the CII regulation into a route optimization tool for vessels in ice. The research decomposes the regulation from evaluating an annual CII value to monitoring an instantaneous CII value over a unit distance. A ship performance model is used to estimate resistance, powering, and fuel consumption. A graph-based pathfinding method is applied to find optimal routes and speeds for the vessel. A hypothetical bulk carrier with ice class 1A Super operating in the Canadian Arctic is considered as a case study. The Polar Operational Limit Assessment Risk Indexing System is applied to promote safe operations in ice. The demonstrations explore route optimization with and without CII considerations, including the exemption for ships sailing ice. The results show that the CII regulation promotes reduced speeds to curb fuel consumption and carbon emissions. The findings also indicate that the exemption for sailing in ice conditions influences routing decisions with results that are contrary to the intent of the regulation. This research provides a tool to support ship operators with voyage planning and policy-makers in evaluating the impact of the CII regulation.

Solar power plant based on a tower-type layout

I suggest the following abstract: In Turkmenistan, the solar energy is a priority among all renewable sources since the duration of sunny days in the country is from 270 to 320 days a year. The article considers the possibilities of creating a solar power plant based on a tower-type layout. The modes of the optical system in the natural and climatic conditions of Turkmenistan are calculated using a mathematical model, the coefficient of efficiency of using the mirror surface of the installation and the distribution of the level of instantaneous local values are determined. The results of the study show that the maximum increase in the energy efficiency coefficient can be achieved with the location of solar panels perpendicular to solar radiation with the dense placement of heliostats on the north side of the tower, then energy efficiency will increase by 25-40% in summer and 10-15% in winter.

Data-Driven Policy Iteration for Nonlinear Optimal Control Problems.

The design of optimal control laws for nonlinear systems is tackled without knowledge of the underlying plant and of a functional description of the cost function. The proposed data-driven method is based only on real-time measurements of the state of the plant and of the (instantaneous) value of the reward signal and relies on a combination of ideas borrowed from the theories of optimal and adaptive control problems. As a result, the architecture implements a policy iteration strategy in which, hinging on the use of neural networks, the policy evaluation step and the computation of the relevant information instrumental for the policy improvement step are performed in a purely continuous-time fashion. Furthermore, the desirable features of the design method, including convergence rate and robustness properties, are discussed. Finally, the theory is validated via two benchmark numerical simulations.

Locating Sources of Sub-Synchronous Oscillations in Wind Farms Based on Instantaneous Energy Supply on Port and Bicoherence

The sub-synchronous oscillation (SSO) which occurred in direct-driven wind generators (DDWG) based wind farms became a research hotspot. The SSO excited the shaft torsional vibration of thermal generators and caused trip failures, leading to economic losses and stabilization problems. However, the existing phasor-based oscillation source locating methods cannot be applied to the SSO since the power system quasi-steady-state assumption was not satisfied in the SSO scenarios. Thus, a novel locating method for SSO sources was urgently required. To fill this gap, this paper proposed an improved method for locating nonlinear sub-synchronous oscillation sources based on Energy Supply on Port (ESP) and bicoherence. The ESP was calculated with the instantaneous values of measured voltages and currents at some predefined network interfaces, i.e., the ports. The tendency of the ESP indicated the transient energy injection from a certain subsystem into the rest of the network during a designated period, which can help figure out the oscillation source of the SSO. After oscillation source localization, the nonlinear index and its threshold were proposed by defining the bicoherence coefficient in consideration of the nonlinear oscillation characteristics. According to the power-quality standard and the comparison of the bicoherence with the threshold, the nonlinearity of the oscillation source was examined. The feasibility and effectiveness of the proposed method were proved in the case study which simulated the oscillation scene of the accident in Hami.

FLAME PROPAGATION IN A NARROW GAP BETWEEN THE PISTON AND CYLINDER OF A HYDROGEN ENGINE

The processes of flame penetration and propagation in a narrow annular gap between the piston and cylinder of a hydrogen piston engine are investigated by the method of 3D mathematical modeling. The model is verified by comparing the changes in pressure and heat release rate in the cylinder obtained from an experimental hydrogen engine, considering the data collected during numerical experiments. The movement of the flame front into the gap is analyzed by changes in the instantaneous local values of the hydrogen fractions in the mixture and the local temperatures of the cold gas (unburned mixture) and combustion products. A comparative analysis of the spread of gasoline and hydrogen flames is carried out. The phenomenon of increasing heat losses in the combustion chamber of a hydrogen engine compared to a gasoline engine, previously confirmed experimentally by different authors and not yet having an acceptable theoretical interpretation, is explained by neglecting the role of heat transfer in the indicated gap.

Application of fiber optic sensors using Machine Learning algorithms for temperature measurement of lithium-ion batteries

Optical fiber sensors using low-coherence interferometry require processing of the output spectrum or interferogram to determine the instantaneous value of the measured quantity, such as temperature, quickly and accurately. Methods based on machine learning are a good candidate for this application. The application of four such methods in an optical fiber sensor of temperature is demonstrated. Using a ZnO-coated sensing interferometer and spectral detection, the sensor is intended for monitoring lithium-ion rechargeable batteries. While the performance of all methods was good, some of them seem to be better suited for this application. Full Text: PDF References B. Wrålsen et al., "Circular business models for lithium-ion batteries - Stakeholders, barriers, and drivers", J. Clean. Prod. 317, 128393 (2021), CrossRef T. Deng et al., "Measuring smartphone usage and task switching with log tracking and self-reports", Mobile Media & Communication 7, 3 (2019), CrossRef Smartphone Subscriptions Worldwide 2027. Statista, DirectLink T. Jerzyński, G. V. Stimson, H. Shapiro, G. Król., "Estimation of the global number of e-cigarette users in 2020", Harm Reduct. J. 18, 109 (2021). CrossRef Battery chemistries, DirectLink Y. Chen, et al., "A review of lithium-ion battery safety concerns: The issues, strategies, and testing standards", J. Energy Chem 59, 83 (2021), CrossRef T. Görgülü, M. Torun, A. Olgun, "A cause of severe thigh injury: Battery explosion", Ann. Med. Surg. 5, 49 (2016) CrossRef T. Maraqa et al., "Too Hot for Your Pocket! Burns From E-Cigarette Lithium Battery Explosions: A Case Series", J. Burn Care Res. 39, 1043 (2018). CrossRef Y. Chen et al., "A review of lithium-ion battery safety concerns: The issues, strategies, and testing standards", J. Energy Chem. 59, 83 (2021), CrossRef Q. Wang et al., "Thermal runaway caused fire and explosion of lithium ion battery", J. Power Sources 208, 210 (2012), CrossRef P. V. Chombo, L. Yossapong, "A review of safety strategies of a Li-ion battery", J. Power Sources 478, 228649 (2020), CrossRef P. Listewnik, M. Bechelany, J. B. Jasinski, M. Szczerska, "ZnO ALD-Coated Microsphere-Based Sensors for Temperature Measurements", Sensors 20, 4689 (2020), CrossRef M. Szczerska, "Temperature Sensors Based on Polymer Fiber Optic Interferometer", Chemosensors 10, 228 (2022), CrossRef M. Kruczkowski et al., "redictions of cervical cancer identification by photonic method combined with machine learning", Sci. Rep. 12, 3762 (2022), CrossRef

Assessment of the spatial distribution of low-temperature plasma parameters on plasma-beam installation

At present continue, studies of the interaction of plasma with structural materials of the first wall and divertor of the ITER international experimental fusion reactor on operating tokamaks and simulated plasma facilities. In the research of the interaction of plasma with the surface of candidate materials TNR an important role plasma parameters play. For determination of local values of the main plasma parameters there is a separate field of research – plasma diagnostics. Plasma diagnostics is the determination of local and instantaneous values of main its parameters: concentration and temperature of charged plasma particles, as well as the distribution functions of various plasma components by energies.This works presents the results of a research to the spatial distribution of local parameters (temperature electrons (Te) and plasma concentration (ne)) of a low-temperature plasma on a plasma-beam installation (PBI) with the help a movable Langmuir probe with the following geometrical parameters of the electrode: length – 4 mm; diameter 0.5 mm. The probe sweep was with the help a Keithley 6487 picoammeter. The processing of volt-ampere characteristics (VAC) was carried out by standard methods.To assess the spatial distribution of the above-mentioned parameters of low-temperature plasma, experiments were carried out with the location of the probe at a distance of 5 mm, 9 mm and 11 mm from the center of the plasma beam at different energies of the primary electron beam in the range from 0.5 keV to 5 keV.The experiments results showed a smooth decrease in plasma concentration in the radial direction.

Effect of wobble parameters on microwelding bead formation of AISI 316L stainless steel

This study examines the impact of wobble movement on a laser beam’s behavior while moving over an AISI 316L stainless steel sample of 1.2 mm thickness during welding. The laser beam oscillatory movement is superimposed on linear movement, using a 400 W fiber laser installed on an experimental bench equipped with a scanner and worktable. Mathematical modeling estimates instantaneous beam speed values, predicting thermal influence on weld bead aspects. Microwelding experiments use autogenous processing with lateral beam oscillation. Two forms of overlapping transverse wobble are tested: one with a circular path and the other describing the mathematical symbol “infinity.” Correlations are evidenced between the input parameters and results obtained in the microwelds, including penetration and width of the beads. Results show that the frequency of movement in a circle and in “infinity” for frequencies from 200 to 400 Hz has no significant influence on the result. Increasing the amplitude of the wobble movement from 0.5 to 2 mm significantly influences the width and depth of the strands generated. The wobble technique is effective in preventing discontinuities in the process, such as porosities. A bead obtained with 300 W, 50 mm/s, 0.5 mm overlapping wobble movement, and 300 Hz circular rotation frequency showed the highest relationship between width and depth.

Nonadditive Entropy Application to Detrended Force Sensor Data to Indicate Balance Disorder of Patients with Vestibular System Dysfunction.

The healthy function of the vestibular system (VS) is of vital importance for individuals to carry out their daily activities independently and safely. This study carries out Tsallis entropy (TE)-based analysis on insole force sensor data in order to extract features to differentiate between healthy and VS-diseased individuals. Using a specifically developed algorithm, we detrend the acquired data to examine the fluctuation around the trend curve in order to consider the individual's walking habit and thus increase the accuracy in diagnosis. It is observed that the TE value increases for diseased people as an indicator of the problem of maintaining balance. As one of the main contributions of this study, in contrast to studies in the literature that focus on gait dynamics requiring extensive walking time, we directly process the instantaneous pressure values, enabling a significant reduction in the data acquisition period. The extracted feature set is then inputted into fundamental classification algorithms, with support vector machine (SVM) demonstrating the highest performance, achieving an average accuracy of 95%. This study constitutes a significant step in a larger project aiming to identify the specific VS disease together with its stage. The performance achieved in this study provides a strong motivation to further explore this topic.

Numerical simulation of the frame structure dynamic behavior utilizing the nonlocal in time damping model

This research is devoted to the numerical analysis of the dynamic response of composite frame structures considering its internal friction properties utilizing the nonlocal in time model of material damping. It is assumed that damping of the structure at the current time moment is dependent not only on an instant value of the strain rate at this moment, but also on the values of strain rates of the previous time history. The longer is the gap between two time points, the lower is the impact of one of them on the other. Such a model in the one-dimensional statement (1 D) could be smoothly integrated to the Finite Element Analysis algorithm and effectively used for the approximation of numerical simulation or physical experiment data. The equation of motion of the frame structure based on the FE model with the nonlocal in time material damping is solved using an implicit scheme. It is shown that such an approach allows one to create a flexible model which could be effectively applied in the case when 1 D models are more preferable than 3D ones, for instance, on the initial design stages or for optimization problem solving.

Comparison Of The Electricity Generation Potentials Of Solar ORC Designed With Different Fluids Depending On Instantaneous Solar Radiation In Four Districts Of Türkiye

In this study, the solar Organic Rankine Cycle (ORC) system was analyzed to meet some of the electrical energy needed in large and medium-sized buildings and large enterprises such as hotels from solar energy. A simulation study was conducted for different districts in Türkiye that are rich in solar energy potential. These counties and the provinces they are affiliated with; Silifke-İçel, Alanya-Antalya, Bodrum-Muğla, Çeşme-İzmir. The power value transferred to the ORC was determined by considering the instantaneous radiation values and sunshine durations for the districts. The performance of solar ORC was determined by comparing fluids from three different organic fluid types. Organic fluids and types used in design; benzene-aromatic hydrocarbon, cyclohexane-alkane, octamethylcyclotetrasiloxane (D4)-siloxane. Considering the maximum electrical energy values obtained from Solar ORC in the summer months, it was seen that 205 MWh electricity generated was obtained for Silifke with benzene at a heat source temperature of 223 oC in July. Maximum solar parabolic trough collector (PTC) specific electric power value was determined as 59.52 W/m2 in Alanya district with benzene in June. When the four districts are evaluated together, it has been determined that benzene performs better than cyclohexane by 3.8% on average and 23% better than D4. When the annual electrical energy values are examined, the highest production was determined as 1625 MWh with benzene fluid in Alanya district.

Development of decomposition-based model using Copula-GARCH approach to simulate instantaneous peak discharge

Estimation of instantaneous peak discharge is important in the design of hydraulic structures and reservoir management. In this study, a new approach called CEEMD-Copula-GARCH is presented for simulating instantaneous peak discharge in the Qale Shahrokh basin, upstream of Zayanderood Dam, Iran. In the developed method, the Complementary ensemble empirical mode decomposition (CEEMD) algorithm was used to analyze the observed values and generate the intrinsic mode function values and residual series. For this purpose, the intrinsic mode function values were simulated based on vine copula and its tree sequence (C-vine, D-vine, R-vine and their independent and Gaussian modes), and the residual series of the CEEMD algorithm were simulated by the GARCH model. The results of simulating instantaneous peak discharge values (m3/s) using the CEEMD-Copula-GARCH approach in the study area showed that the amount of simulation error based on the RMSE statistic compared to the CEEMD-Copula model and simulation without decomposition has improved by about 20 and 70%, respectively. The model’s efficiency was also estimated based on the Nash–Sutcliffe efficiency in the proposed approach of 0.99, and the certainty of the proposed approach was also confirmed based on the presented violin plot. According to the presented results, the proposed approach has high accuracy and efficiency in the simulation of instantaneous peak discharge (m3/s), which can be used in the flood control system design and flood management. Using the methodology proposed in this study, multivariable models can be used in simulating univariate series with high accuracy.

Smartphone-Assisted Flexible Electrochemical Sensor Platform by a Homology DNA Nanomanager Tailored for Multiple Cancer Markers Field Inspection.

In this work, an ingenious sensor technology was established by integrating the EBFCs on a flexible paper strip carrier (PE) that was used for simultaneous detection of tumor markers in complex samples. Adopting high performance ultrathin graphdiyne (U-GDY) as the substrate can increase the enzyme load, accelerate the electron transfer rate, and significantly enhance the detection sensitivity. A homologous DNA nanomanager strategy cleverly uses signal switches to recycle and amplify target miRNAs, while the smartphone receives real-time instantaneous current values to realize multivariate detection. Electrochemical data show that the detection limits (LODs) of miRNA-21 and miRNA-155 are 0.09 and 0.15 fM in the wide concentration range. The results confirm that the tailored sensor platform provides a strategy for the early cancer diagnosis and lays the foundation for the construction of a flexible wearable platform.

Instantaneous Square Current Signal Analysis for Motors Using Vision Transformer for the Fault Diagnosis of Rolling Bearings

Using vibration signals for bearing fault diagnosis can generally achieve good diagnostic results. However, it is not suitable for practical industrial applications due to the restricted installation and high cost of vibration sensors. Therefore, the easily obtainable motor current signal (MCS) has received widespread attention in recent years. Meanwhile, traditional fault diagnosis methods cannot meet the diagnostic accuracy requirements because of the low signal-to-noise ratio (SNR) of the MCS. Committed to achieving bearing fault diagnosis through MCS, a rolling bearing fault diagnosis method, ISCV-ViT, based on the MCS and the Vision Transformer (ViT) model, is proposed. In particular, a signal processing method based on the instantaneous square current value (ISCV) is proposed to process the MCS directly obtained through a frequency converter into time-domain images. Then, the ViT model is applied for bearing fault diagnosis. Finally, experimental verification is carried out based on the public bearing dataset of Paderborn University (PU) and the bearing dataset of Shenzhen Technology University (SZTU). The analysis of the experimental results demonstrates that the average accuracy of the ISCV-ViT for the two datasets is up to 96.60% and 94.87%, respectively.

Synchronized measurement of instantaneous convective heat flux and velocity fields in wall-bounded flows

This work presents an experimental setup for acquiring synchronized wall and flow field measurements in a turbulent boundary layer (TBL). Instantaneous measurements of the convective heat transfer distribution at the wall and of the flow field are carried out simultaneously, using synchronized wall-parallel planar particle image velocimetry and infrared thermography. A low-thermal-inertia heated-thin-foil sensor is embedded in the wall beneath the TBL to measure the wall temperature maps with enough temporal resolution. The unsteady energy balance of the heated foil can be solved to restore the instantaneous value of the convective heat transfer coefficient on the wall. A detailed description of the sensor design is included. Furthermore, owing to the relatively low signal-to-noise ratio of instantaneous temperature fluctuation measurements, a recipe for data processing is proposed. A study to characterize the uncertainty of the experimental setup design is also performed. The overall agreement in the correlation between wall heat transfer and velocity fields with the literature supports the validity of the proposed approach. This solution is potentially interesting for flow control purposes, where sensing is performed at the wall.

Damped response of porous functionally graded viscoelastic cylindrical shells

In this article, the behavior of viscoelastic porous functionally graded (FG) shells regarding the free and damped forced vibration analysis is investigated. The differential equations are derived by using higher order shear deformation theory. Using Hamilton’s principle and the energy method, the equations of motion are obtained and solved using Navier’s method. The damping effect is implemented into the analysis by means of Kelvin and linear standard viscoelastic models. With the correspondence principle, the transition from elastic material properties to viscoelastic material properties is achieved. First, a free vibration analysis is performed to verify the accuracy of the developed algorithm and obtained results are compared with the existing studies in the literature. Afterwards, a parametric study considering two different viscoelasticity models is performed. In the first parametric example, damped forced vibration analysis is performed for simply supported FG cylindrical shell using linear standard viscoelastic model as the viscoelastic model. Then, damped forced analysis is performed using Kelvin viscoelastic model for simply supported FG cylindrical shell. Analyses are performed in Laplace domain. The obtained results are transferred to time domain using Durbin’s inverse Laplace transform method. The displacement graphs are given for the damped forced vibration examples. In the performed parametric studies, the effects of various porosity coefficients, ratios of instantaneous value, retardation times of the relaxation function and damping ratios on the analysis are investigated.

A Forward-Type Single-Stage Multi-Input Inverter With Series-Time-Overlapping Power Supply

A Forward type single-stage multi-input inverter with series-time-overlapping power supply is proposed. The circuit structure and topological family, energy management control strategy (EMCS), high frequency (HF) switching process analysis, the relationship between multiple duty cycles and power decoupling, common mode interference suppression between multiple inputs are fully studied. The circuit structure is composed of multi-input selection switches in series and an isolated bidirectional Forward type single input single output inverter. This topological family includes 6 circuits such as full-bridge type. A master-slave energy management SPWM compound control strategy with independent control of input source power based on input voltage feedforward and output voltage feedback is proposed. It realizes the energy management of the input source by controlling the instantaneous value of the output voltage and the output power ratio of the multiple inputs and achieves the smooth switching between the two power supply modes. The designed and developed 3kVA inverter prototype has excellent performances such as single-stage power conversion, HF electrical isolation, high conversion efficiency, small size and weight, wide duty cycle adjustment range, high output waveform quality, and strong load adaptability.

A Facility’s Energy Demand Analysis for Different Building Functions

A more accurate determination of energy demands for buildings is of utmost importance for estimating future energy demands. This article presents two novel ideas that have the potential to contribute to a more precise determination of expected energy demands. The first idea involves accounting for a building’s function more thoroughly, which enables the determination of different energy demands for two or more identical buildings, depending on their respective usage functions. According to a case study, the heating energy demand can be up to twice as high in a commercial facility compared with a residential building. Similarly, the cooling energy requirement can also differ. The second idea concerns determining the heating degree day (HDD) and cooling degree day (CDD) values from the daily minimum and maximum temperatures. This idea may be relevant when few instantaneous values are available for the daily mean temperature. According to the case study, the calculated values from the daily minimum and maximum temperatures follow the HDD and CDD values specified from the daily mean temperature. However, the difference is less than 2% for the heating season and higher for the cooling season. Therefore, further research is required to refine the constants in the cooling equation.

Computation of Vascular Parameters: Implementing Methodology and Performance Analysis.

This paper presents the feasibility of automated and accurate in vivo measurements of vascular parameters using an ultrasound sensor. The continuous and non-invasive monitoring of certain parameters, such as pulse wave velocity (PWV), blood pressure (BP), arterial compliance (AC), and stiffness index (SI), is crucial for assessing cardiovascular disorders during surgeries and follow-up procedures. Traditional methods, including cuff-based or invasive catheter techniques, serve as the gold standard for measuring BP, which is then manually used to calculate AC and SI through imaging algorithms. In this context, the Continuous and Non-Invasive Vascular Stiffness and Arterial Compliance Screener (CaNVAS) is developed to provide continuous and non-invasive measurements of these parameters using an ultrasound sensor. By driving 5 MHz (ranging from 2.2 to 10 MHz) acoustic waves through the arterial walls, capturing the reflected echoes, and employing pre-processing techniques, the frequency shift is utilized to calculate PWV. It is observed that PWV measured by CaNVAS correlates exponentially with BP values obtained from the sphygmomanometer (BPMR-120), enabling the computation of instantaneous BP values. The proposed device is validated through measurements conducted on 250 subjects under pre- and post-exercise conditions, demonstrating an accuracy of 95% and an average coefficient of variation of 12.5%. This validates the reliability and precision of CaNVAS in assessing vascular parameters.

Three-Dimensional Air Velocity Distributions in the Vicinity of a Mine Heading’s Sidewall

The presented paper describes the results of an experiment determining the instantaneous values of velocity vector components of the air stream at selected spots of the boundary layer formed at the sidewalls of the mine heading in the ŁP type steel arch support. The experiment was carried out in a mine heading in an active hard coal mine. A 3-axis thermoanemometric probe was used to obtain three-dimensional distributions of the velocity and turbulent values, such as turbulence intensity and turbulent kinetic energy of the flowing ventilation air stream. The analysis of the measurement results was aided by a numerical solution of the discussed case of flow. The research results presented in this paper provide a basis for extensive studies of the description of velocity distribution and other turbulent quantities within the near-sidewall structures of a mine heading. The objective of these tasks is to improve the accuracy and reliability of numerical calculations relating to air flow in mine headings.