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Protein kinases are key signaling nodes that regulate fundamental biological and disease processes. Illuminating kinase signaling from multiple angles can provide deeper insights into disease mechanisms and improve therapeutic targeting. While fluorescent biosensors are powerful tools for visualizing live-cell kinase activity dynamics in real time, new molecular tools are needed that enable recording of transient signaling activities for post hoc analysis and targeted manipulation. Here, we develop a light-gated kinase activity coupled transcriptional integrator (KINACT) that converts dynamic kinase signals into "permanent" fluorescent marks. KINACT enables robust monitoring of kinase activity across scales, accurately recording subcellular PKA activity, highlighting PKA activity distribution in 3D cultures, and identifying PKA activators and inhibitors in high-throughput screens. We further leverage the ability of KINACT to drive signaling effector expression to allow feedback manipulation of the balance of GαsR201C-induced PKA and ERK activation and dissect the mechanisms of oncogenic G protein signaling. Real-time biosensors have been developed for visualizing kinase activity dynamics, but they are confronted with many challenges. Here, the authors develop a light-gated KINACT integrator for post hoc analysis of transient kinase activity and signalling manipulation. [ABSTRACT FROM AUTHOR]

This research article presents the design and development of a custom-made inside-mouth support for microphone placement, aiming to improve sound quality and minimize background noise. The support was designed to ensure proper articulation and pronunciation. To ensure biocompatibility, a medical-grade polymer poly methyl methacrylate (PMMA) was chosen due to its low melting temperature and ability to manufacture clear and transparent pieces suitable for 3D printing. The design of the support is done using Fusion 360, and later analysis is done on the support in ANSYS workbench software to analyse the behaviour of the support subjected to dynamic and static loads. The support was subjected to transient structural, explicit dynamic, and static structural analysis to investigate its response to different loading conditions and evaluate its performance in real-world scenarios. The transient response of the PMMA material was found to be safer and more reliable. The maximum average values of total deformation, maximum principal elastic strain, and maximum principal stress obtained from the transient structural analysis were 3.5258e-003 mm, 2.1363e-005 mm/mm, and 0.035209 MPa, respectively. The explicit dynamic analysis resulted in maximum average values of 1.2917e-003 mm, 5.9808e-006 mm/mm, and 5.3201e-003 MPa, respectively. The static structural analysis gave average values of 2.7015e-003 mm, 2.0882e-005 mm/mm, and 2.9142e-002 MPa, respectively. Additionally, the support was tested using two different materials, silicone rubber, and PMMA, for comparison. The results showed that PMMA had several advantages over silicone rubber, including lower total deformation and maximum principal stress, making it more reliable for use in real-world scenarios. In conclusion, the inside-mouth support designed and developed in this study can improve sound quality and minimize background noise in areas where high noise predominates. Using PMMA as the material of choice for the support ensures biocompatibility and improves the overall performance and reliability of the device. [ABSTRACT FROM AUTHOR]

Responding to threats in the real world demands a sophisticated orchestration of freeze and flight behaviors dynamically modulated by the neural activity. While the medial prefrontal cortex-basolateral amygdala (mPFC-BLA) network is known to play a pivotal role in coordinating these responses, the mechanisms underlying its population dynamics remain vague. As traditional Pavlovian fear conditioning models fall short in encapsulating the breadth of natural escape behaviors, we introduce a novel dataset to bridge this gap, capturing the defensive strategies of mice against a spider robot in a natural-like environment. The adaptive escape behaviors and concurrent mPFC-BLA activity in eight mice were monitored using wireless local field potential (LFP) and video recordings, both individually and in groups. Our data offers a unique avenue to explore the neural dynamics that govern fear- and vigilance-induced threat responses in isolated and social contexts. Supplemented by detailed methodologies and validation, the dataset allows for the analysis of the transient neural oscillatory dynamics, with prospective implications for the fields of neuroscience, robotics, and artificial intelligence. [ABSTRACT FROM AUTHOR]

Researchers have shown considerable interest in phase change material-based triple-tube units as a possible solution for storing and utilizing thermal energy. The uses of fins in the triple-tube unit were introduced by the researchers to address the low thermal conductivity of the phase change materials. In present study, the application of sinusoidal wavy-shaped fins in the phase change material (RT-82)-based triple-tube unit has been designed and a two-dimensional numerical model is developed for the transient analysis. The recharging–discharging of the phase change material are analyzed for configurations without fin, with conventional rectangular fins, and with sinusoidal wavy-shaped fins of varying amplitudes and numbers of peaks. The validation of the model was done against the experimental result of the published article. The thermal performance and fluid flow dynamics are quantitatively evaluated by analyzing the melt fraction, temperature, velocity and heat flux variation. The result shows that a conventional rectangular fin reduces the recharging–discharging time by 59.36% and 64.26%, respectively, when compared to without fins configuration. The use of sinusoidal wavy-shaped fins further reduces recharging–discharging times by 3.15% and 2.72%, respectively. When the amplitude of the sinusoidal wavy-shaped fins is increased, there is a significant improvement in the recharging–discharging process of the PCM. On the other hand, there is no significant effect when the number of peaks is increased. The pairs of cases with nearly identical PCM volume storage but different sinusoidal wavy-shaped fins configurations show significant variations in total recharging–discharging times. [ABSTRACT FROM AUTHOR]

This research explores economic growth dynamics in five ASEAN countries (1980–2020), analyzing the short and long-term impact of financial development (FD), oil prices, investment (INV), and inflation on GDP growth. Panel ARDL analysis reveals a transient positive link between FD and long-term GDP growth, necessitating a holistic approach for short-term stability. Similarly, oil prices exhibit long-term volatility, urging diversification strategies. In contrast, consistent and significant relationships exist between INV and GDP growth in both time frames, underscoring investment's pivotal role. The study emphasizes managing inflation for sustained growth, offering vital insights for policymakers, economists, and analysts in fostering ASEAN's economic stability. [ABSTRACT FROM AUTHOR]

At present, the dynamic studies of cylindrical shells are mostly limited to free- and forced vibration, the transient response of which is very limited. It is worth noting that no one has conducted research on the transient response of cylindrical shells with rotating speed and initial geometrical imperfection. Based on this fact, the present article is dedicated to discussing the transient response of rotating carbon nanotubes reinforced composite cylindrical shells with initial geometrical imperfection for the first time. Firstly, four distribution patterns of carbon nanotubes are taken into consideration, in which the material properties are calculated with the help of the mixing rule. Subsequently, considering the effect of initial geometric imperfection, the dynamic model is built according to Love's thin shell theory. Then, the motion equation of the shell is derived based on the Hamilton principle. Assuming three different boundary conditions, the Galerkin principle is applied to reduce the dimensionality of the motion equation, which leads to a nonlinear equation containing central radial displacement, pulse load, and time. Simultaneously, two comparative analyses are developed to confirm the validity of this article, and the results indicate that there is no significant difference between the current results and existing literature. By summarizing the characteristics of four pulse loads, the blast load is determined for numerical analysis. Finally, the Runge–Kutta method is employed to acquire the transient response with various influence factors. The current research provides theoretical guidance for structural design and vibration reduction of the spacecrafts subjected to pulse loads. [ABSTRACT FROM AUTHOR]

Cognitive radio networks (CRNs) offer a promising solution for improving spectrum utilization. However, ensuring quality of service (QoS) for heterogeneous secondary users (SUs) during spectrum handoff, particularly under high primary network traffic, poses challenges. This study develops a Markov-based analytical model to evaluate the gain of a non-switching spectrum handoff technique using a hybrid interweave-underlay spectrum access strategy, considering sensing errors. The proposed model assesses the effects of the hybrid spectrum access method for prioritized traffic across multiple SU classes, aiming to meet QoS requirements for delay-sensitive traffic. The study examines the CRN's short-term behavior and realistic queueing scenarios by analyzing the system's transient dynamics. Different spectrum access methods are compared for evaluation purposes. The analysis focuses on evaluating the effectiveness of the enhanced hybrid spectrum access scheme compared to individual interweave and hybrid interweave-underlay spectrum access strategies in terms of QoS provisioning for heterogeneous SUs. The results demonstrate increased throughput and improved spectrum utilization with the suggested scheme, affirming its suitability for satisfying QoS requirements for both delay-sensitive and delay-tolerant users. [ABSTRACT FROM AUTHOR]

This study investigated the flow characteristics of the high-flow path of a two-dimensional supersonic intake in a turbine-based combined-cycle engine utilizing Reynolds-averaged Navier–Stokes (RANS) and detached eddy simulation (DES) turbulence schemes with a moving mesh in ANSYS to analyze the flow effects of varying rotational cowl angles. In addition, proper orthogonal decomposition (POD) was employed to analyze the flow modes. This study revealed that the mass flow rate and pressure recovery increased linearly with an increasing cowl opening angle, and fluctuations were observed when the cowl was positioned parallel to the ramp surface in DES transient solutions. Conversely, a significant decrease in mass flow rate and pressure recovery ratio occurred when the cowl angle was located at fixed − 4.78° in steady solutions. POD utilizing snapshots derived from RANS k-wSST and DES indicated that the first to fourth modes were dominant, accurately representing the original velocity field with a cumulative mode energy ratio of over 80 %. [ABSTRACT FROM AUTHOR]

This paper presents the transient behavior of an earthing system under the influence of lightning current injected in to it. Vertical rods and horizontal electrodes buried in homogeneous soil are considered in this analysis. State-space representation (SSR)-based transmission line methodology (TLM) is adopted with nonlinear parameters for modeling the earthing electrodes in the time domain. Soil ionization phenomenon is taken up with the presence of residual resistivity. In this method, soil resistivity variation is adopted to evaluate the soil ionization phenomenon that occurs due to changes in the electric field. This study incorporates mutual coupling between the electrode segments for low and high soil resistivity. Earthing electrodes are subjected to high-magnitude lightning current impulse with different peaks. Transient voltage and impulse impedance are calculated to analyze the transient behavior of earthing electrodes with soil ionization. The impulse impedance of vertical earthing rods and horizontal electrodes is calculated and compared with the power frequency impedance. Percentage ohmic reduction between them is also reported. The influences of a critical electric field, soil resistivity and lightning magnitude on the transient performance of earthing electrodes are calculated. Also, an effect of the front time of lightning current impulse for a fixed peak on the impedance of the earthing electrode is evaluated and significant changes are observed. Simulated results are validated with the experimental and theoretical results reported in the literature, and adequate agreements are achieved. [ABSTRACT FROM AUTHOR]

The present work is an attempt to develop a simple and accurate finite element formulation for the transient analysis of size-dependent S functionally graded material (S-FGM) micro-folded plates based on first-order shear deformation theory and taking exact shear correction factor in conjunction with modified couple stress theory in the formulation. Two micromechanical models, viz. rule of mixture and local representative volume elements (LRVE), are used to estimate the temperature-dependent material property of the S-FGM micro-folded plate. The top layer of the S-FGM micro-folded plate is subjected to a thermal shock, whereas the bottom layer is maintained at ambient temperature. Parametric studies are performed to investigate the effect of the number of folds, crank angle, shear correction factor, temperature gradient, material length scale ratio and boundary conditions on transient analysis of S-FGM micro-folded plates subjected to thermal shock. It is observed from results that a maximum change of 6.4661% and 10.5623% in amplitude of the non-dimensional tip deflection of a double-folded Al2O3/Ti–6Al–4V S-FGM cantilever microplate is observed on employing exact value of shear correction factor of 0.8009 and on increasing the temperature gradient from 100 to 300 K, respectively, obtained using LRVE micromechanical model. [ABSTRACT FROM AUTHOR]

In this article, a size-dependent analysis is conducted for the geometrically nonlinear transient vibration of a porous microplate in the presence of nonlocal and modified stress tensors, solved by the isogeometric analysis (IGA) method. Pursuing the primary objective, the effective characteristics of porous graphene platelet material (GPL) from uniform and non-uniform porosity distributions are estimated by utilizing the Halpin–Tsai model. The governing equations and the integrated nonlocal modified couple stress theory for nonlinear transient vibration are derived based on uniform rational B-spline. Furthermore, the efficient discretization technique is capable of meeting C1 continuity requirements. It is demonstrated that the theory, introducing a combination of two tensors into the higher-order shear deformation theory, can accurately capture the size effects on the transient dynamic responses. The magnitude of transient displacements is diminished, and the ability of the nano-/microplate to withstand impulse loads increases as the pores concentrate on the center of the neutral axis regarding the non-uniform porosity distribution. The enhancement of the nonlinear transient responses is attributed to the increase in modified couple stress, which generates greater structural rigidity than that reduced by nonlocality. Finally, the new assessment results are detailed by analyzing the size-dependent parameter, nonlocal variation, porosity coefficient, and the different porosity distribution schemes that aim to decide the responses of the GPLs' microstructure. [ABSTRACT FROM AUTHOR]

In the realm of microfluidics, a critical issue prevails: The commercially available flow sensors are situated external to the microfluidic chip, resulting in an inherent deficiency of precise operational insights. Applications such as biochemistry, drug development, single cell analyses, gradient generators, biomedical devices and proactive healthcare demand dependable data for broader utilization. In the present work, we introduce a microfluidic flow sensor designed to gauge electrolyte flow rates on-chip inside a microchannel by measuring electrochemical resistance of electrolytic bubbles within a circuit comprising electrolytic fluid and inter-digitated electrodes. This sensor design features a Si wafer substrate with micropatterned Ti/Pt electrodes bonded to a polydimethylsiloxane (PDMS) microchannel using oxygen plasma. The sensor has been characterized for electrolytic fluid (0.1 M NaCl), 600 μ m wide microchannel, 0–500 μ l/min range of flow, 3V dc power input, and 25 ∘ C room temperature conditions. Sensor response has been compared for electrolyte concentrations (0.1 M to 0.4 M NaCl), channel width (400–1200 μ m), and input power (1–5 V) corresponding to a given flow rate. The sensor 3 σ resolution calculated from calibration curve is observed to be 5 μ l/min for lower flow rates (0–100 μ l/min) and 100 μ l/min for higher flow rates (100–500 μ l/min). The limit of detection (LoD) of the sensor is 1 μ l/min. An algorithm based on the trapezoidal rule enabling flow rate prediction within 5 s has been implemented. The proposed flow sensor works over a broad range of flow rates, although with different sensitivity, presenting a novel method employing the electrolysis bubble size and volume for flow rate detection. [ABSTRACT FROM AUTHOR]

This work investigates performance improvement the of ring voltage-controlled oscillator. Particle swarm optimization (PSO) techniques are used on both the physical and schematic levels to optimize the design parameter values (width of the NMOS " W n " and PMOS " W p "). By utilizing this strategy, multiple time-taking iterations can be reduced and done in a single cycle, thereby increasing the likelihood that the ring VCO will function to the best of its ability. After getting the optimized values for the design parameters of the ring VCO's, the circuit has been designed for the performance analysis. The same is demonstrated by evaluating the performance of the circuit and confirming the results of the transient analysis and noise analysis carried out with Cadence tools under a variety of different operating conditions using the 45 nm technology process. The analysis has been carried out in a variety of PVT corners (fast–fast, slow–slow, fast–slow, and slow–fast). [ABSTRACT FROM AUTHOR]

The emergence of retinal progenitor cells and differentiation to various retinal cell types represent fundamental processes during retinal development. Herein, we provide a comprehensive single cell characterisation of transcriptional and chromatin accessibility changes that underline retinal progenitor cell specification and differentiation over the course of human retinal development up to midgestation. Our lineage trajectory data demonstrate the presence of early retinal progenitors, which transit to late, and further to transient neurogenic progenitors, that give rise to all the retinal neurons. Combining single cell RNA-Seq with spatial transcriptomics of early eye samples, we demonstrate the transient presence of early retinal progenitors in the ciliary margin zone with decreasing occurrence from 8 post-conception week of human development. In retinal progenitor cells, we identified a significant enrichment for transcriptional enhanced associate domain transcription factor binding motifs, which when inhibited led to loss of cycling progenitors and retinal identity in pluripotent stem cell derived organoids. Formation of the retina during development involves the coordinated action of retinal progenitor cells and their differentiated cell types, which is key for producing a functioning eye. Here the authors provide a detailed atlas of human retinal development, combining scRNA-seq and spatial transcriptomics, and identify key genetic factors that mediate retinal progenitor cell proliferation and differentiation. [ABSTRACT FROM AUTHOR]

The bond-graph (BG) enables to model multi-physics systems in the energy domains. This paper shows that BG models are an alternative, more intuitive and simpler to interpret, graphical tool as compared to existing dynamic models for performance prediction of the line-start permanent-magnet synchronous motors (LSPMSMs). It includes electrical, magnetic, and mechanical energy domains where the stator windings, rotor bars, and permanent magnets are the main components of the model. The dynamical equations of the proposed BG are extracted and solved using the MATLAB ordinary differential equation solver for a sample LSPMSM. The dynamics of the studied LSPMSM is investigated under two operating conditions (1) a healthy motor and (2) a motor with broken rotor bars. The simulation results are compared with the finite-element analysis (FEA) as the most accurate method to simulate the electric motor behaviour. It is shown that the proposed BG model accurately predicts the performance parameters of the motor such as current, torque, and speed under various operating conditions. In addition to the modelling validation, the transient behavior of the LSPMSM are discussed to describe the possible reasons for its behaviour during transient and steady-state operating conditions. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to develop a portable upscaled automated phase-controlled impact device (APCID) for industrial applications which allows impact synchronous modal analysis (ISMA), an operational modal analysis technique to be performed under actual operating condition with minimum no. of impacts. Methods: The design of this upscaled APCID is validated by static and transient structural analysis for its stability and strength. Its performance is tested on an industrial water pump. Results: The lightweight and portable upscaled APCID design can impart large and constant impact forces, and it is found stable and safe. Field testing also showed good suppression of cyclic load component using ISMA with upscaled APCID as all modes identified in stationary condition of the pump were also identified in running condition of the pump. Conclusion: The upscaled APCID is a portable and practical device which allows in-service modal analysis with known input excitation to be performed efficiently on mechanical structures in industrial setups. [ABSTRACT FROM AUTHOR]

The three-dimensional numerical manifold method (3D-NMM), which is based on the derivation of Galerkin's variation, is a powerful calculation tool that uses two cover systems. The 3D-NMM can be used to handle continue-discontinue problems and extend to THM coupling. In this study, we extended the 3D-NMM to simulate both steady-state and transient heat conduction problems. The modelling was carried out using the raster methods (RSM). For the system equation, a variational method was employed to drive the discrete equations, and the crucial boundary conditions were solved using the penalty method. To solve the boundary integral problem, the face integral of scalar fields and two-dimensional simplex integration were used to accurately describe the integral on polygonal boundaries. Several numerical examples were used to verify the results of 3D steady-state and transient heat-conduction problems. The numerical results indicated that the 3D-NMM is effective for handling 3D both steady-state and transient heat conduction problems with high solution accuracy. [ABSTRACT FROM AUTHOR]

Pump-jet holds a pivotal position in various marine applications, underscoring the need for comprehending their transient behavior for the purpose of design enhancement and performance refinement. This paper employs Reynolds-averaged Navier–Stokes equations method in conjunction with Detached Eddy Simulation model. The study delves into the ramifications of accelerating and decelerating ducts, distinguished by camber f and attack angles α, on transient hydrodynamic characteristics. The hydrodynamic characteristics are investigated numerically, after the validation of the numerical methodology by comparing simulation outcomes against experimental results. Subsequently, the study delves into propulsion characteristics, followed by an exploration of time-domain and frequency-domain data transformed through fast Fourier transform to analyze thrust fluctuations and pulsating pressures. Additionally, a detailed examination of pressure distribution and velocity field is provided, aiming to dissect the mechanisms through the variations in f and α influence the flow field. Findings suggest that the outlet velocity of accelerating ducts significantly surpasses the inlet velocity, a behavior contrasted by decelerating ducts. Notably, the patterns of accelerating and decelerating ducts resulting from alterations in f exhibit consistent characteristics with those brought about by changes in α. However, several opposite characteristics surface in transient flow field due to the distinct modifications in the duct profile. Furthermore, by considering vorticity magnitude distribution and vortices, a comparative analysis elucidates the effects of varying f and α on rotor and stator trailing vortices. This contributes to understanding the flow instability mechanism under differing duct configurations. It is evident that changes in f and α exert significant influence on both performance and flow field. [ABSTRACT FROM AUTHOR]

In this paper we establish best approximation type estimates for the fully discrete Galerkin solutions of transient Stokes problem in L 2 (I ; L 2 (Ω) d) and L 2 (I ; H 1 (Ω) d) norms. These estimates fill the gap in the error analysis of the transient Stokes problems and have a number of applications. The analysis naturally extends to inhomogeneous parabolic problems. The best type L 2 (I ; H 1 (Ω)) error estimate are new even for scalar parabolic problems. [ABSTRACT FROM AUTHOR]

This paper presents a method for analyzing constant-pressure drawdown test of infinite-conductivity fractured wells in bounded reservoirs. The presented method is based on the Tiab direct synthesis approach. The fracture and reservoir parameters are directly determined from the rate and rate derivative of the well test data. New equations describing the elliptical flow regime and the transition from the pseudoradial regime to the boundary-dominated regime of different rectangular reservoirs are also presented. The various flow regimes occurring during the well test are easily identified based on the shape of the plotted data and the slope of each flow regime. The unique features of the slopes of the various regimes and their intersection points are utilized to determine the fracture half-length, formation permeability, skin factor, well drainage area, and reservoir shape factor. Moreover, new equations defining the intersection points of the straight lines corresponding to different flow regimes are presented. These equations are very important for confirming the precision of the calculated results. A systematic process demonstrating the application of the proposed method to linear, elliptical, pseudoradial, and boundary-dominated regimes is well delineated. Comprehensive examples are presented to validate the efficiency of the proposed technique. The examples show that even if some of the flow regimes are not fully developed, the method can still be used to determine the formation and fracture properties using information obtained from the remaining flow regimes. This is one of several advantages of the proposed technique over conventional techniques. [ABSTRACT FROM AUTHOR]

In this work, a novel refined higher-order shear deformation plate theory is integrated with nonlocal elasticity theory for analyzing the free vibration, bending, and transient behaviors of fluid-infiltrated porous metal foam piezoelectric nanoplates resting on Pasternak elastic foundation with flexoelectric effects. Isogeometric analysis (IGA) and the Navier solution are applied to the problem. The innovation in the present study is that the influence of the inplane variation of the nonlocal parameter on the free and forced vibration of the piezoelectric nanoplates is investigated for the first time. The nonlocal parameter and material characteristics are assumed to be material-dependent and vary gradually over the thickness of structures. Based on Hamilton's principle, equations of motion are built, then the IGA approach combined with the Navier solution is used to analyze the static and dynamic response of the nanoplate. Lastly, we investigate the effects of the porosity coefficients, flexoelectric parameters, elastic stiffness, thickness, and variation of the nonlocal parameters on the mechanical behaviors of the rectangular and elliptical piezoelectric nanoplates. [ABSTRACT FROM AUTHOR]

Sommerfeld effect is a nonlinear jump phenomenon which occurs in unbalanced rotor–motor system, and its characteristics provide an idea of power required to operate the system in the post-resonance region. In this article, the steady-state and full transient characterization of Sommerfeld effect in an unbalanced rotor–motor active magnetic bearing system is studied by considering the nonlinear bearing force of the active magnetic bearing (AMB) in the system equation. The homotopy perturbation method (HPM) is used to solve the nonlinear coupled second-order differential equations of the 16-pole leg AMB system analytically, and the steady-state vibration amplitude of the rotor dynamic system is calculated using the same method. The numerical power balance technique is used to study the steady-state Sommerfeld effect in the system, and its characterization provided the range of unachievable speed range for the rotor dynamic system. The full transient analysis of the rotor–motor AMB system is done analytically, and the exact voltage requires to pass through the resonance, while the system accelerated by the motor is obtained. From the steady-state analysis, it is observed that as the bias current is increased from 0 to 20 A, the jump voltage required to escape resonance has been decreased from 94.7 to 71.5 V. From frequency response curve, it is also observed that as the bias current is increased, it decreases the steady-state vibration amplitude up to 13.8% and a peculiar phenomenon like shifting of resonance is also occurred. It is also observed that percentage of reduction in the jump voltage required for passage through resonance are obtained as 4.5%, 17%, and 24% as the bias current supply to the AMB is increased from 0 to 5, 15 A, and 20 A, respectively, for transient analysis. Both the steady-state and transient responses were attained by increasing the bias current supply to the AMB system, and it is observed that the system vibration amplitude is reduced significantly at the resonance while increasing the bias current. The Sommerfeld effect characterization with respect to bias current supply to the AMB system is provided a vital idea of major reduction in the required jump voltage for passage through the resonance and achievable rotor speeds to operate the system in the post-resonance region. [ABSTRACT FROM AUTHOR]

The limited surface coverage and activity of active hydrides on oxide surfaces pose challenges for efficient hydrogenation reactions. Herein, we quantitatively distinguish the long-puzzling homolytic dissociation of hydrogen from the heterolytic pathway on Ga2O3, that is useful for enhancing hydrogenation ability of oxides. By combining transient kinetic analysis with infrared and mass spectroscopies, we identify the catalytic role of coordinatively unsaturated Ga3+ in homolytic H2 dissociation, which is formed in-situ during the initial heterolytic dissociation. This site facilitates easy hydrogen dissociation at low temperatures, resulting in a high hydride coverage on Ga2O3 (H/surface Ga3+ ratio of 1.6 and H/OH ratio of 5.6). The effectiveness of homolytic dissociation is governed by the Ga-Ga distance, which is strongly influenced by the initial coordination of Ga3+. Consequently, by tuning the coordination of active Ga3+ species as well as the coverage and activity of hydrides, we achieve enhanced hydrogenation of CO2 to CO, methanol or light olefins by 4-6 times. Zhu et al. report a quantitative and time-resolved analysis of hydrogen activation on Ga2O3, specifically shedding light on the long-standing puzzle of homolytic dissociation as opposed to the heterolytic pathway on oxides. [ABSTRACT FROM AUTHOR]

This work describes the implementation of a novel dynamic Arbitrary LagrangianEulerian (ALE) formulation for the simulation of pavement structures loaded by rolling tires in a finite element framework. The proposed formulation enables the simulation of dynamic effects like acceleration, deceleration and variation of the wheel load on the pavement. The ALE scheme is described for a hyperelastic St. Venant-Kirchhoff material capable of finite deformations. With the adoption of this dynamic ALE formulation, a significant improvement in terms of speed and efficiency of the simulation is achieved in comparison to a classical transient Lagrangian formulation. This is primarily because only the relevant portion of the mesh around the applied load needs to be discretized and simulated. Another benefit is that a cumbersome moving load formulation does not need to be implemented. The results show satisfactory agreement with a conventional Lagrangian simulation with a moving load. [ABSTRACT FROM AUTHOR]

For the tower crane, the luffing trolley and cargoes are equivalent to concentrated force. This study established a moving load model. The transient dynamic analysis method was used to carry out dynamic simulation, analyze and obtain the vibration characteristics of the boom under luffing and lifting, and calculate the fatigue life of the key components of the boom based on the S-N curve. The analysis results showed that the greater the luffing speed, the greater the arm end vibration amplitude. The lifting speed has influence on the amplitude and frequency of vibration. Under the worst working conditions, the minimum service life of the top chord 638 of the most dangerous component was 17.96 years, which can meet the requirements of the safety regulations for tower cranes. At the same time, the damage degree of the dangerous component during luffing was greater than that during lifting. [ABSTRACT FROM AUTHOR]

Nowadays, integration of large-scale wind farms (WFs) into power systems is experiencing rapid growth. As this rapid integration can affect transient stability significantly, employing doubly fed induction generator (DFIG)-based wind turbines, which have shown better behavior regarding system stability, has attracted much attention. This research contributes to the literature by investigating the transient stability of the power system with increasing penetration of DFIG-based WFs. In the proposed framework, the current-balance form is utilized for the network equations, and in this way, transient stability is performed using time-domain simulation. According to the simulation results, when the rate of wind power generation exceeds 0.7 per-unit, the increasing trend of the critical clearing time (CCT) is reversed and the CCT decreases greatly with the increased wind power penetration. In addition, the reactive power compensation by DFIG, the gearbox ratio, the power system strength, and DFIG parameters are comprehensively investigated as effective parameters on transient stability. Since the rated rotor speed of DFIG significantly impacts the electrical torque and machine currents, the reduction of the rated rotor speed due to the change of the gearbox ratio has been investigated as one of the effective factors to improve the transient stability. The simulation results demonstrate the effectiveness of the proposed approach in improving power system transient stability. [ABSTRACT FROM AUTHOR]

Homotopy perturbation method (HPM) is applied in this paper for the transient study of some queueing/inventory/healthcare models. Semi-analytic approximate transient probabilities are obtained as power series in the time variable. The numerical implementation of the method using a programming language like MATLAB, is easy. However, the number of terms that is required in the above power series, to get an accurate approximation, grows with time. This obstacle is overcame by adopting a step-by-step HPM method. Implementation of the method is discussed in the case of the classic M/M/1 queue, the (s, S) inventory model with random replenishment time but without backlogs, the (s, S) inventory model with positive service and replenishment times, allowing infinite backlogs, and the Markov chain model for the patient handoff process in emergency departments. Numerical experimentation has been carried out to evaluate the efficiency of the method and to understand the challenges involved in its implementation. [ABSTRACT FROM AUTHOR]

The deformations resulting from tunnel analyses for heavily squeezing ground may be very large, necessitating numerical formulations that consider geometric nonlinearity. Alternatively, for a certain class of problems, routine small strain analyses can be performed, and their results can be corrected to account for large strains by means of a simple hyperbolic expression proposed a few years ago. The present paper shows that this correction equation is sufficiently accurate for practical purposes even in the case of anisotropic material behaviour and for hydromechanically coupled, steady state or transient analyses of tunnels. The accuracy of the equation prediction varies amongst these cases but is satisfactory overall for the purpose of preliminary calculations, thus broadening its value and usefulness as a preliminary design tool. [ABSTRACT FROM AUTHOR]

A two-stage computational framework is proposed to optimize the radiated noise and weight of a large mining planetary gear reducer under the rated conditions, based on a combination of response surface methodology and multi-objective optimization. The well-established transient dynamic analysis model of a large mining planetary gear reducer, which is used to analyze the mechanical strength and acoustic characteristics of the gear reducer. A unified experimental design is developed to obtain the response surface of the gearbox radiated noise and the mass of the gearbox housing. After obtaining the multi-objective optimization function, the multi-objective optimization problem for a lightweight and low-noise gearbox is performed using non-dominated sorting from the Genetic Algorithm II (NSGA-II). The research results demonstrates the effectiveness of the proposed optimization method in reducing vibrating amplitude and weight of the gearbox. This is crucial for minimizing energy consumption and enhancing the overall performance of the system. Additionally, the optimized gearbox design not only saves energy but also contributes to the reduction of carbon emissions, making it environmentally friendly. [ABSTRACT FROM AUTHOR]

The forced transient vibration of a multi-cracked bridge model under moving loads is investigated in this work based on Green's function method, and Euler–Bernoulli beam model is used to establish the dynamic model of the bridge. Parameters of a bridge are chosen based on civil engineering standards in this study, and moving loads correspond to real vehicle weights whose values are obtained from civil engineering standards. Laplace transform is used to eliminate the time variable in the dynamic model and transform the dynamic model into a dynamic equation without time variable in the complex space, and the eigenfunction expansion method is used to solve the transformed dynamic equation. In the eigenfunction expansion process, a special mode shape function is used in this study to simplify the solution process. The forced transient vibration of the uncracked bridge model under multiple moving loads is first derived, and the transfer matrix method is used to derive the analytical solution of the dynamic response of the multi-cracked bridge model based on the response of the uncracked bridge model. In the numerical solution part, the present solution is verified by comparison with the result in the literature. Effects of the crack depth and bridge depth-span ratio on the first natural frequency of the beam is revealed by numerical calculation. Effects of vehicle types, loads, numbers of vehicles, vehicle spacing, and crack depths and locations on the forced transient response of the mid-span displacement of the bridge model are investigated. Effects of bridge depth-span ratios, vehicle speeds, load locations, and crack depths on the quasi-steady-state response of the bridge model are discussed. Parameter analyses for relations of the depth-span ratio and crack depth with the mid-span displacement are included, and confidence intervals for quadratic fit coefficients reach 95% in these parameter analyses, which indicates that the quadratic fit formula fits well with the present solution. Results of this study can be extended for diverse numerical simulations and experimental studies related to cracked bridge models under moving loads. [ABSTRACT FROM AUTHOR]

UT-Austin's Devine Fracture Pilot Site, 50 miles southwest of San Antonio, Texas, has been targeted for a comprehensive, multidisciplinary development of fracture diagnostic techniques that are cross-validated by ground-truth data acquisition near a recently created, 175-ft-deep, horizontal hydraulic fracture (Ahmadian et al. 2018 Demonstration of proof of concept of electromagnetic geophysical methods for high resolution illumination of induced fracture networks. In Proceedings of the SPE Hydraulic Fracturing Technology Conference and Exhibition, The Woodlands, Texas, USA, 23–25 January 2018. SPE-189858-MS.). To evaluate the fracture diagnostic methods at this site, we conducted injection tests with a predefined volumetric flow-rate profile, resembling a diagnostic fracture injection test on September 2020. Subsequently, we developed hydrogeological and geomechanical models based on flow-rate and bottomhole-pressure measurements. History-matching efforts using a simplified layer-cake hydrogeological model resulted in the field-scale formation permeability of 9.87 × 10–15 m2 (10 mD) and Darcy-scale fracture permeability. The analysis of the bottomhole pressure and injection-rate history showed that (1) the newly created horizontal fracture was closed adjacent to the injection well pre-injection and (2) the initial pump-pressure increase at a nominal volumetric injection rate led to near-well fracture reopening, fluid conductivity increase, and abrupt injection-rate increase. To overcome hydrogeological-model limitations of predicting fracture reopening throughout injection, we extended the modeling to a finite-element, poroelastic analysis of horizontal-fracture growth using a cohesive-zone model. Using this fracture-reopening model, we improved the history match of the transient-pressure response during the experiment by adjusting the hydromechanical properties. Post-injection pressure transient analyses helped reduce uncertainty in the overburden-stress gradient, and the initial hydraulic-fracturing simulation verified the plausibility of achieving the surveyed propped fracture area. Highlights: We proposed a procedure for developing a hydrogeological model to improve the history matching of the bottomhole pressure during a hydraulic-fracture reopening. We compared the outcomes of this hydrogeological model with a calibrated poroelastic model, showing the advantage of the later model for fracture reopening and re-closure. We suggest using a spatiotemporally variable fracture permeability obtained from a poroelastic model in a hydrogeological model to simulate fracture reopening. We estimated an almost similar overburden-stress gradient using G-function pressure transient analysis of post-shut-in bottomhole pressure data from two short and long injection tests. [ABSTRACT FROM AUTHOR]

A decoupled inverter pair sense amplifier (DIPSA) is proposed for improved sensing in differential SRAM. The DIPSA is designed at 45-nm technology node with a decreased sensing delay of 31.44% and 28.44% over the conventional latch-type sense amplifier (CLSA) and current-latched SA with an NMOS footswitch (CSANF) at 1.1 V, respectively. The performance of DIPSA is validated using delay and power consumption comparison with prior SA designs across a set of supply voltages. Monte Carlo simulation for 3 σ deviation yields a reliable design with no read failures and mean delay of 488.81 ps across the 1k data points with a deviation of 54.87 ps. The threshold voltage variation contribution to process variation is considered for these calculations. The sizing of the decoupling transistors is discussed and its impact on the delay and power of DIPSA shown. The performance of existing voltage and current sense amplifiers is compared to DIPSA. [ABSTRACT FROM AUTHOR]

In this work, a procedure to obtain two-port admittance models of buried cables illuminated by incident electromagnetic fields for the analysis of transients in the frequency domain is presented. The procedure is based on cascading two-port admittance models of various cable segments, avoiding the numerical problems that chain matrix representations may have. To obtain results in the time domain, the Numerical Laplace Transform method is used. [ABSTRACT FROM AUTHOR]

This work merges the reconfigurable FET concept and the multigate structure concept, i.e., ringFET to form a new device concept called the reconfigurable ringFET. The DC performance metrics like ON current, OFF current, ION/IOFF ratio, subthreshold slope, threshold voltage, and transconductance are extracted. Reconfigurable ringFETs are examined for their response to heavy-ion radiation using 3D technology computer-aided design simulations, and the device's sensitive position is determined by the single-event transient analysis on interactions of heavy ions during normal incidence. For an N-type device, it has been found that the source region is the least sensitive, while the intergate length region near the drain is the most sensitive zone. For a P-type device, it has been found that the intergate length region near the drain is the most sensitive, whereas the drain region is the least sensitive zone. The impact of radiation at various angles of incidence is also investigated. It has also been found that the collected charge decreases with increasing angle of incidence. [ABSTRACT FROM AUTHOR]

We present a physics-informed deep learning model for the transient heat transfer analysis of three-dimensional functionally graded materials (FGMs) employing a Runge–Kutta discrete time scheme. Firstly, the governing equation, associated boundary conditions and the initial condition for transient heat transfer analysis of FGMs with exponential material variations are presented. Then, the deep collocation method with the Runge–Kutta integration scheme for transient analysis is introduced. The prior physics that helps to generalize the physics-informed deep learning model is introduced by constraining the temperature variable with discrete time schemes and initial/boundary conditions. Further the fitted activation functions suitable for dynamic analysis are presented. Finally, we validate our approach through several numerical examples on FGMs with irregular shapes and a variety of boundary conditions. From numerical experiments, the predicted results with PIDL demonstrate well agreement with analytical solutions and other numerical methods in predicting of both temperature and flux distributions and can be adaptive to transient analysis of FGMs with different shapes, which can be the promising surrogate model in transient dynamic analysis. [ABSTRACT FROM AUTHOR]

In flexible manipulators, it is crucial to suppress the end-point vibrations. Velocity motion profile which is used to actuate a manipulator is important to reduce the vibrations, especially during high-speed motions. In this study, effect of three different seven segment velocity motion profiles on the end-point transient and residual vibrations of a flexible manipulator was investigated experimentally and by performing finite element simulations with ANSYS. These motion profiles were third-order polynomial S-curves and two different trigonometric (harmonic and pure sinusoidal) S-curve motion profiles. Symmetrical velocity motion profiles were used, and time parameters of the motion profiles were selected either half-integer multiples or integer multiples of flexible manipulator's natural period. The results obtained from the experiments were compared with the transient analysis results obtained from ANSYS. The effects of time parameters of all motion profiles on endpoint vibrations were shown by comparing them in terms of amplitudes. Errors in the natural frequency measurements of the flexible manipulator change the time parameters of the motion profiles, and this change adversely affects the endpoint passive vibration control. The sensitivity of passive control results to 4% natural frequency measurement error is shown for all motion profiles. [ABSTRACT FROM AUTHOR]

In this study, for the first time, an off-grid zero-energy building with hydrogen energy storage integrated with two hydrogen cars is simulated and analyzed transiently. Regarding the novelties, for the first time, two types of wind turbines are compared as an energy supplier of the building, and all human living requirements are considered. Therefore, the study can fill in the gap of a comprehensive analysis of such off-grid hydrogen-integrated zero energy building by considering two types of wind turbines as its energy supplier. The mentioned wind turbines are compared in terms of total capital cost, and the cheapest one is specified. The fuel consumption of two typical hydrogen cars is considered. An occupant's thermal comfort level and domestic hot water usage are considered. Trnsys software is employed to examine the building's annual transient performance. Electrical split heat pumps and humidifiers are used to keep the residents warm. A solar collector heats a hot water storage tank for residential water heating. When renewable energy sources are unavailable, energy is stored and used through a hydrogen energy system. This way, electricity will be transformed by utilizing an alkaline electrolyzer into hydrogen and stored in a tank. Using fuel cells, stored hydrogen converts to electricity. Waste heat from fuel cells and electrolyzers is also an additional heating source for a hot water storage tank. Results demonstrate that five vertical-axis or seven horizontal-axis wind turbines are required to supply the energy needs of a typical 150 m2 building in Boston. Both of them have 2 kW rated power. The cheapest case is horizontal-axis wind turbines. The given number of wind turbines meets the building's energy requirements for two hydrogen cars. The monthly expected discontent percentage is below 9% when using a suitable split electrical heat pump and humidifier, and the predicted mean vote is in the range of − 0.4 and 0.4. An evacuated tube solar collector can meet four building residents' hot water needs. Typical buildings can be transformed into off-grid zero energy for windy cities like Boston by mounting all required energy suppliers, including solar collectors and wind turbines, on the rooftop. [ABSTRACT FROM AUTHOR]

The present study proposes a system that can reduce environmental pollution emissions while simultaneously improving production capacity. The current research innovation is the use of the thermoelectric generator system and the organic Rankine cycle in conjunction with a gas turbine based on the Brayton cycle. The thermodynamic engineering equation solver software is utilized in this study to model the investigated system and acquire the system analysis results. The efficiency of the gas turbine, the competency criterion of a thermoelectric generator, compressor pressure ratio, inlet temperature to the organic turbine, and inlet temperature to gas turbine are the most relevant and practical parameters in this study. In addition, the system's exergy study revealed that the most exergy was destroyed in the combustion chamber, evaporator, gas turbine, and thermoelectric. Also, the economic analysis of the system showed that the increased cost of the system is related to the Brayton cycle unit and the steam cycle unit, respectively. Finally, a comparative case study was conducted for four cities: Abadan, Esfahan, Mashhad, and Shiraz, to evaluate the total production capacity of the system. The system performance results were evaluated with the changes in annual ambient temperature. The results showed that the system works best in the cooler climate of Mashhad. [ABSTRACT FROM AUTHOR]

The high-precision machine tool's dynamic, static, and rigid nature directly affects the machining efficiency and surface quality. Static and dynamic analyses are essential for the design and improvement of precision machine to ensure good tool performance under difficult and demanding machining conditions. In this study, the performance of a high-precision machine tool was analyzed using its virtual model created using CAD. Static and model analysis using ANSYS Workbench software was conducted to establish the tool's static deformation and static stiffness. Furthermore, the static and dynamic characteristics of the tool were explored using a finite element modeling approach to study their performance. In particular, the structure, static force, modal, frequency spectrum, and topology optimization of machine tools were primarily analyzed. Using model analysis, we found the first four different frequencies (22.5, 28.9, 40.6, and 47.4 Hz) and vibration type, which suggested of a weak link. Further static structural analysis revealed that the deformation of the spindle was 67.26 μm. An experimental static rigidity analysis was performed, and the experimental deformation values of the tool and spindle were obtained. The static and dynamic characteristics, as well as the accuracy and efficiency of the finite element model, were verified by comparing the data with the finite element analysis (FEA) results. Subsequently, we modified the settings and analysis model to ensure that the analysis results were consistent with the experimental findings. The error between the two results was within 1.56%. For an applied load of 5000 N on the spindle nose, the tool nose transient response was 0.5 s based on transient analysis. Under the condition that the structural deformation is as constant as possible, the lightweight structure may achieve the minimum weight and enhance the natural frequency; thus, the ideal structure will be obtained, and finite element analysis will then be performed. The optimal conditions for topology optimization include a lightweight structure, reduced structural deformation, and increased natural frequency of the structure. The developed method improves structural optimization, increases the ability of the product to be manufactured, and offers designers a variety of price-effective options. [ABSTRACT FROM AUTHOR]

The thermal deep-level transient spectroscopy (DLTS) technique was applied to study the defect states and their activation energies of a polyurethane-based polymer network (PELLE) insulator. It was demonstrated that decomposition analysis of exponential transients allows a more accurate determination of the activation energy of the defective states. Two groups of activation energies for the PELLE polymer were observed, ranging from 0.49 eV to 1.9 eV and − 7.84 eV to − 2.53 eV, which were assigned to changes in the bond properties in the hard and soft segments of the studied polymer, respectively. The applicability of the DLTS method for the characterization of polymers was demonstrated. It was shown that the DLTS technique could contribute to a more comprehensive picture of the properties of polymers. [ABSTRACT FROM AUTHOR]

This study presented an equivalent continuum modeling method for analysis of the transient response of the large space truss structures with nonlinear elastic joints. Firstly, a two-node hybrid joint-beam element model was established for a truss member with two nonlinear joints at its both ends based on the geometrical relationship and equilibrium condition between the truss member and the nonlinear joints. Subsequently, an equivalent 8-DOFs nonlinear beam element including the warping and distortional deformations was derived for approximating the repeating element of the beam-like truss structure with rectangular cross-sections based on the energy equivalence method, the external force vector and nonlinear restoring force vector of the truss structure were transferred to the external force vector and nonlinear restoring force vector of the equivalent beam element. The equation of motion of the equivalent nonlinear beam model was solved by the combination of the Newmark-β method and the Newton–Raphson iteration method. In the numerical studies, a cantilevered truss structure and a spacecraft with a truss support structure were simulated by considering the joint have piece-wise linear stiffness. The correctness and high efficiency of the presented modeling method was verified by comparison of the results of the equivalent models with the original nonlinear finite element models established by ANSYS. [ABSTRACT FROM AUTHOR]

Transient thermal analysis of mass concrete using ANSYS finite element program has become popular. In ANSYS, material properties and heat generation rate of concrete are typically input as constant, time-dependent, or temperature-dependent. However at early-age, the material properties and heat generation rate of mass concrete are significantly time- and temperature-dependent which should not be ignored. In this study, a detailed description of how to correctly predict the early-age thermal behavior of concrete is described and a modified USERMATTH subroutine for ANSYS is presented. In this subroutine, the heat generation rate, thermal conductivity, and specific heat for each element were programmed to be temperature, age, and location dependent. The early-age concrete material properties are described as a function of the degree of hydration. Experimental verification was conducted using three concrete batches containing supplementary cementitious materials delivered by ready-mix trucks. Each concrete batch was used to cast a 1.2-m cube with steel formwork and a 1-m insulated cube. The temperature differentials from the ANSYS simulations and experiments compared well, with a maximum error within 1 °C. Results show that the proposed method can predict the amplitude and time of peak temperatures at different locations. The thermal analysis technique developed in this study can be used to precisely analyze the temperature differentials in a mass concrete structure and help reduce the risk of early-age thermal cracking. [ABSTRACT FROM AUTHOR]

The catalytic oxidation of CO by O2 to form CO2 over Pt based catalysis is one of the most studied catalytic reaction leading to controversial mechanism descriptions. Steady State Isotopic Transient Kinetic Analysis (SSITKA) coupled with InfraRed (IR) spectroscopy is a powerful technique to study heterogeneous reaction mechanisms combining both the observation of adsorbed species on the catalyst surface and kinetic measurements. In this paper, SSITKA-IR technique was applied to study the CO oxidation reaction in presence and absence of CO2 in order to distinguish between active and spectator intermediates formed during the reaction. Linear carbonyl and bridged carbonyl type species adsorbed on metallic Pt0 were clearly identified as active intermediates at low temperature (131 °C). In contrast, the hydrogen-carbonate species formed during CO oxidation reaction were proven to be inactive species in CO2 formation but rather due to the re-adsorption of CO2 product itself on alumina surface. [ABSTRACT FROM AUTHOR]

Ocean bottom pressure-gauge (OBP) records play an essential role in seafloor geodesy. Oceanographic fluctuations in OBP data, however, pose as a significant noise source in seafloor transient crustal deformation observations, including slow slip events (SSEs), making it crucial to evaluate them quantitatively. To extract the significant fluctuation phenomena common to multiple observation networks, including oceanographic fluctuations and tectonic signals, we applied principal component analysis (PCA) to the 3-year Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) OBP time series for 40 stations during 2016–2019. PCA could separate several oceanographic signals based on the characteristics of their spatial distributions, although evident transient tectonic signals could not be confirmed from the observed pressure records during this observed period. The spatial distribution of the first four principal components (PCs) reflected the common component, inclined component along sea depth, longitude component, and parabola-like pattern, respectively. By subtracting each PC (in particular, PC-2 and PC-4) from the time series, we could significantly reduce the sea depth dependence of OBP records, which has been highlighted in several previous studies and is also evident in this region. We interpreted PCs 2–4 as the reflection of the strength and meandering of ocean geostrophic currents based on a comparison with the PC spatial distribution of the numerical oceanographic models. In addition, to evaluate the ability of PCA to separate transient tectonic signal from OBP time series, including oceanographic fluctuations, we conducted a synthetic ramp assuming an SSE by rectangular fault and then applied PCA. The assumed synthetic tectonic signal could be separated from the oceanographic signals and included in the principal component independently depending on its amplitude, suggesting that the spatial distribution of each PC would change if the amplitude of the synthetic signal were sufficiently large. We propose a transient event-detection method based on the spatial distribution difference of a specific PC with or without a tectonic signal. We used the normalized inner product (NIP) between these PCs as the indicator of their similarities. This method can detect transient tectonic signals more significantly than the moment-magnitude scale of 5.9 from OBP records. [ABSTRACT FROM AUTHOR]

Monitoring of a well and the surrounding reservoir performances is a crucial component in evaluating on-going and planning future well and field operations. This is carried out at all stages of a well life-span: from exploration to production and, sometimes, after abandonment. Despite tremendous progress in reservoir simulations, simple and fast techniques for well-reservoir performance evaluation are still demanded in the industry, especially in the context of the vast amount of permanent well monitoring data continuously accumulated. Such techniques are of special interest for on-the-fly well monitoring to detect and alarm about deteriorating performance issues. Installation of permanent pressure gauges in many wells motivated development of time-lapse Pressure Transient Analysis (PTA), capable of revealing and monitoring of different factors governing well performance and reservoir production. The paper describes PTA-based metrics introduced in the context of automated interpretation of time-lapse pressure responses and their derivatives. The paper begins with a review of time-lapse PTA applications in the oil and gas industry and examples of patterns formed by the time-lapse pressure transients and their derivatives in the log–log scale. Then, integral-based PTA-metrics for well-reservoir performance analysis are introduced. The metrics enable to distinguish between reservoir and well-reservoir connection contributions to a well's performance using the Bourdet derivative, while avoiding the need for selecting and matching of a well-reservoir model. The metrics were further tested with synthetic well models and field cases. The testing demonstrated high accuracy of the metrics for the cases of vertical wells with stable transient patterns. Testing for the horizontal well cases has confirmed reliability of the metrics for the stable patterns, while change of the patterns may reduce the metrics reliability. Model independence and using only pressure and rate measurements as input data are the main advantages of the metrics for integration into automated interpretation workflows and on-the-fly analysis intensively developed in the industry. [ABSTRACT FROM AUTHOR]

Chilling Tolerant Divergence 1 (COLD1) gene consists of Golgi pH Receptor (GPHR) as well as Abscisic Acid-linked G Protein-Coupled Receptor (ABA_GPCR), which are the major transmembrane proteins in plants. This gene expression has been found to be differentially regulated, under various stress conditions, in wild Saccharum-related genera, Erianthus arundinaceus, compared to commercial sugarcane variety. In this study, Rapid Amplification of Genomic Ends (RAGE) technique was employed to isolate the 5′ upstream region of COLD1 gene to gain knowledge about the underlying stress regulatory mechanism. The current study established the cis-acting elements, main promoter regions, and Transcriptional Start Site (TSS) present within the isolated 5′ upstream region (Cold1P) of COLD1, with the help of specific bioinformatics techniques. Phylogenetic analysis results revealed that the isolated Cold1P promoter is closely related to the species, Sorghum bicolor. Cold1P promoter-GUS gene construct was generated in pCAMBIA 1305.1 vector that displayed a constitutive expression of the GUS reporter gene in both monocot as well as dicot plants. The histochemical GUS assay outcomes confirmed that Cold1P can drive expression in both monocot as well as dicot plants. Cold1P's activities under several abiotic stresses such as cold, heat, salt, and drought, revealed its differential expression profile in commercial sugarcane variety. The highest activity of the GUS gene was found after 24 h of cold stress, driven by the isolated Cold1P promoter. The outcomes from GUS fluorimetric assay correlated with that of the GUS expression findings. This is the first report on Cold1P isolated from the species, E. arundinaceus. [ABSTRACT FROM AUTHOR]

We present a rigorous analysis of the transient evolution of nearly circular bilayer interfaces evolving under the thin interface limit, ε ≪ 1 , of the mass preserving L 2 -gradient flow of the strong scaling of the functionalized Cahn–Hilliard equation. For a domain Ω ⊂ R 2 we construct a bilayer manifold with boundary comprised of quasi-equilibria of the flow and a projection onto the manifold that associates functions u in an H 2 tubular neighborhood of the manifold with an interface Γ embedded in Ω . The linearization of the flow about the manifold does not present a clear spectral separation of modes normal and tangential to the manifold. The dimension of the parameterization of the interfaces and the bilayer manifold controls both the normal coercivity of the manifold and the coupling between normal and tangential modes, both of which increase with this dimension. The key step in the analysis is the identification of a range of dimensions in which coercivity dominates the coupling, permitting the closure of the nonlinear estimates that establish the asymptotic stability of the manifold. Orbits originating in a thin, forward invariant, tubular neighborhood ultimately converge to an equilibrium associated to a circular interface. Projections of these orbits yield interfacial evolution equivalent at leading order to the regularized curve-lengthening motion characterized by normal motion against mean curvature, regularized by a higher order Willmore expression. The curve lengthening is driven by absorption of excess mass from the regions of Ω away from the interface, leading to high dimensional dynamics that are ill-posed in the ε → 0 + limit. [ABSTRACT FROM AUTHOR]

We explore the capabilities of multiresolution wavelet analysis (MWA) to characterize complex dynamics based on short data sets that can be applied for diagnosing inter-state transitions. Using the example of chaos–hyperchaos transitions in the model of two interacting Rössler systems, we establish the minimum amount of data necessary for reliable separation of chaotic and hyperchaotic oscillations and discuss how this amount changes depending on the length of the transient process. We then discuss transitions between wakefulness and artificial sleep in mice and estimate the duration of electroencephalograms (EEG) that provide separation between these states. [ABSTRACT FROM AUTHOR]

Understanding the impact of fractures on fluid flow is fundamental for developing geoenergy reservoirs. Pressure transient analysis could play a key role for fracture characterization purposes if better links can be established between the pressure derivative responses (p′) and the fracture properties. However, pressure transient analysis is particularly challenging in the presence of fractures because they can manifest themselves in many different p′ curves. In this work, we aim to provide a proof-of-concept machine learning approach that allows us to effectively handle the diversity in fracture-related p′ curves by automatically classifying them and identifying the characteristic fracture patterns. We created a synthetic dataset from numerical simulation that comprised 2560 p′ curves that represent a wide range of fracture network properties. We developed an unsupervised machine learning approach that can distinguish the temporal variations in the p′ curves by combining dynamic time warping with k-medoids clustering. Our results suggest that the approach is effective at recognizing similar shapes in the p′ curves if the second pressure derivatives are used as the classification variable. Our analysis indicated that 12 clusters were appropriate to describe the full collection of p′ curves in this particular dataset. The classification exercise also allowed us to identify the key geological features that influence the p′ curves in this particular dataset, namely (1) the distance from the wellbore to the closest fracture(s), (2) the local/global fracture connectivity, and (3) the local/global fracture intensity. With additional training data to account for a broader range of fracture network properties, the proposed classification method could be expanded to other naturally fractured reservoirs and eventually serve as an interpretation framework for understanding how complex fracture network properties impact pressure transient behaviour. Article Highlights: Detailed characterization of naturally fractured geoenergy reservoirs using pressure transient analysis. Proof-of-concept workflow that identifies the characteristic pressure derivative responses using machine learning. Identification of key geological controls on pressure derivative responses in naturally fractured geoenergy reservoirs. [ABSTRACT FROM AUTHOR]

Purpose: A nondestructive, noncontact approach for the estimation of elastic parameters of fully clamped thin sheet is presented in current work. Frequency response of pulsed laser impulse excited clamped thin plate is used for the estimation of elastic parameters. Methods: Elastic parameters like Young's modulus, shear modulus and Poisson ratio of fully clamped thin square soda lime glass plate are determined by pulsed laser impulse excitation of vibrations. Initially, frequency response is recorded by measuring vibrations using quadrature Michelson interferometer. Then, finite element method (FEM) based simulations are performed in ANSYS Workbench for the identification of mode shapes for transverse modes of vibrations. Experimentally measured natural frequencies are compared with the modes of vibrations from FEM for the determination of elastic parameters. Materials: Soda lime glass fixed in an Aluminum holder. Results: The obtained values of parameters are in agreement with analytical calculations within 3% and Young's modulus measured by three point bending method within 1.5%. Effect of holder on the modes of vibrations of glass is found to be less than 2%. Conclusion: Both simulations and experimental results are matched iteratively and extra bending and twisting modes of holder are identified. Best fitted elastic parameters for results are further verified using other methods. Due to the noncontact nature of the pulsed laser excitation and laser-based measurements, current technique can easily be applied for the measurement of Young's modulus at in-situ harsh environments even at elevated temperatures. [ABSTRACT FROM AUTHOR]