Miracle-dz/UniFAR-FTUs huggingface dataset:
Study on the Impacts of Capillary Number and Initial Water Saturation on the Residual Gas Distribution by NMR

The determination of microscopic residual gas distribution is beneficial for exploiting reservoirs to their maximum potential. In this work, both forced and spontaneous imbibition (waterflooding) experiments were performed on a high-pressure displacement experimental setup, which was integrated with nuclear magnetic resonance (NMR) to reveal the impacts of capillary number (Ca) and initial water saturation (Swi) on the residual gas distribution over four magnitudes of injection rates (Q = 0.001, 0.01, 0.1 and 1 mL/min), expressed as Ca (logCa = −8.68, −7.68, −6.68 and −5.68), and three different Swi (Swi = 0%, 39.34% and 62.98%). The NMR amplitude is dependent on pore volumes while the NMR transverse relaxation time (T2) spectrum reflects the characteristics of pore size distribution, which is determined based on a mercury injection (MI) experiment. Using this method, the residual gas distribution was quantified by comparing the T2 spectrum of the sample measured after imbibition with the sample fully saturated by brine before imbibition. The results showed that capillary trapping efficiency increased with increasing Swi, and above 90% of residual gas existed in pores larger than 1 μm in the spontaneous imbibition experiments. The residual gas was trapped in pores by different capillary trapping mechanisms under different Ca, leading to the difference of residual gas distribution. The flow channels were mainly composed of micropores (pore radius, r < 1 μm) and mesopores (r = 1–10 μm) at logCa = −8.68 and −7.68, while of mesopores and macropores (r > 10 μm) at logCa = −5.68. At both Swi= 0% and 39.34%, residual gas distribution in macropores significantly decreased while that in micropores slightly increased with logCa increasing to −6.68 and −5.68, respectively.
Modelling of an energy-efficient open double-glazing unit for the main climatic conditions of Mexico

Abstract The annual thermal evaluation of an open double-glazing unit (ODGU) is presented. The ODGU was modelled using two double-glazing configurations: DCC (clear glass + air + clear glass) and DCA (clear glass + air + absorbent glass). Numerical simulations were performed for the warmest design-day on each month of 2016 in four different climatic conditions in Mexico. The pseudo-transient simulations were carried out using an in-house code based on the finite volume method. To obtain the results, 5856 computational runs were necessary. From the results, the DCA configuration was observed to show the best thermal performance to reduce heat flux that passes through the inside space in the extreme warm dry climate with average reductions of 97 W/m2, followed by the semi-arid climate with 84 W/m2 and the tropical wet and dry climate with 82 W/m2 on a yearly basis. On an annual average, the DCA configuration in the extreme warm dry climate reached almost twice the mass flow rates than those observed in the temperate climate. From the numerical simulations, we have concluded that the use of the low-cost DCA configuration in warm climates was the best solar passive strategy for saving energy in buildings throughout the year.
Overview and Comparison of Modulation and Control Strategies for a Nonresonant Single-Phase Dual-Active-Bridge DC–DC Converter

The nonresonant single-phase dual-active-bridge (NSDAB) dc–dc converter has been increasingly adopted for isolated dc–dc power conversion systems. Over the past few years, significant research has been carried out to address the technical challenges associated with modulations and controls of the NSDAB dc–dc converter. The aim of this paper is to review and compare these recent state-of-the-art modulation and control strategies. First, the modulation strategies for the NSDAB dc–dc converter are analyzed. All possible phase-shift patterns are demonstrated, and the correlation analysis of the typical phases-shift modulation methods for the NSDAB dc–dc converter is presented. Then, an overview of steady-state efficiency-optimization strategies is discussed for the NSDAB dc–dc converter. Moreover, a review of optimized techniques for dynamic responses is also provided. For both the efficiency and dynamic optimizations, thorough comparisons and recommendations are provided in this paper. Finally, to improve both steady-state and transient performances, a combination approach to optimize both the efficiency and dynamics for an NSDAB dc–dc converter based on the reviewed methods is presented in this paper.
Contributions on the automatic tuning of LC networks using on-chip circuits

Radio-frequency identification (RFID) has been successfully used in many applications including object identification, logistics, localization and it has also been considered as an enabling technology for the Internet of things. Both the reader and the tag of the RFID system have a resonating network that enables data and energy communication. However, a mistuning of these resonating networks can either reduce reading range or lead to a disposal of the tag. Hence, to solve this problem we propose novel LC tuning systems that can be integrated on an RFID chip to automatically tune the tag. It is possible to automatically tune LC networks using a Qenhanced technique as the core of the analog tuning system. In this regard, one LC tuner based on negative resistances is described in the thesis. Moreover, it is possible to tune an LC network using a sample of the RF limiter current, that are present in RFID tags. It is possible to say that these tuners complement each other in the sense that the former system tunes its resonating network based on voltages, while the latter tunes its LC network based on currents. It is also feasible to tune resonating circuits when their step response are analyzed. So we propose in this thesis another circuit that can measure the Q of its resonating network and also how close it is from the resonating frequency. This system digitally reports these parameters and it can also be used used in filters. The systems are designed using a 130-nm CMOS process and they occupy an area smaller than 0.035 mm, making the presented prototypes suitable for integration on an RFID chip. This thesis contains the two tuners that operate at 125 kHz and the LC parameter extractor operates at 900 MHz.
A Simplified Pulse Width Modulation Algorithm for Model Prediction of Cascade Static Synchronous Compensator

Received: 10 December 2018 Accepted: 3 February 2019 To ensure the DC-side voltage stability of cascade static synchronous compensator (STATCOM) units, this paper proposes a pulse width modulation (PWM) algorithm based on virtual flux (VF) for model prediction. Firstly, a VF model was established, which predicts the ideal voltage vector under zero VF error, calculates the DC-side voltage per unit and rounds it to the ideal voltage, and determines the module state by balancing the DC-side voltage between the unit modules. Secondly, the author explained the flow of PWM algorithm based on VFtracking, and analyzed the waveform features. Finally, the proposed PWM algorithm was applied to the STATCOM of cascade multi-level converter. The results of simulation, field experiment and analysis show that the VF-based PWM algorithm for the model prediction of cascade STATCOM can achieve good modulation effect and strike a balance of DC-side voltage between the unit modules. Thus, the proposed PWM algorithm is both rational and feasible.
Determination of the Material Parameters in the Holzapfel-Gasser-Ogden Constitutive Model for Simulation of Age-Dependent Material Nonlinear Behavior for Aortic Wall Tissue under Uniaxial Tension

In this study, computational simulations and experiments were performed to investigate the mechanical behavior of the aorta wall because of the increasing occurrences of aorta-related diseases. The study focused on the deformation and strength of porcine and healthy human abdominal aortic tissues under uniaxial tensile loading. The experiments for the mechanical behavior of the arterial tissue were conducted using a uniaxial tensile test apparatus to validate the simulation results. In addition, the strength and stretching of the tissues in the abdominal aorta of a healthy human as a function of age were investigated based on the uniaxial tensile tests. Moreover, computational simulations using the ABAQUS finite element analysis program were conducted on the experimental scenarios based on age, and the Holzapfel–Gasser–Ogden (HGO) model was applied during the simulation. The material parameters and formulae to be used in the HGO model were proposed to identify the failure stress and stretch correlation with age.
A Novel Current Solution for Torque Ripple Suppression of BLDCM With Minimal Rotor Eddy-Current Loss

In this paper, a novel current solution is proposed to suppress the electromagnetic torque ripple of brushless dc motor (BLDCM), and simultaneously minimize the rotor eddy-current loss to prevent thermal demagnetization of the permanent magnets. To determine the current solution, an optimizing problem of the rotor loss is developed, subjecting to the constraints of average torque and the sixth harmonic torque. Finite dc supply is also considered. In addition, an improved model of the rotor loss is proposed with a simpler expression of quadratic form, so that the problem can be solved analytically. A comparison with the square-wave and minimal-copper-loss current solutions is studied based on a 3.77 kW, 12000 r/min BLDCM, which indicates that the proposed solution performs as well as the two solutions in suppressing the torque ripple and producing stator losses, but the rotor loss can be significantly reduced by at least 86% and 35%, respectively. Precision of the rotor loss model and performance of the proposed solution are validated experimentally on the 3.77 kW BLDCM setup.
Design of diplexer‐integrated filtering power divider with high isolation

A compact size and high isolation diplexer‐integrated filtering power divider (D‐IFPD) is presented in this study. The proposed multifunctional circuit consists of one distributed coupling feeding line, two different stub‐loaded trimode resonators, and two open‐ended three‐line parallel coupled lines. With the utilization of the distributed coupling technique, no additional matching circuit is needed for D‐IFPD design. The measured results show that the proposed D‐IFPD is centered at 1.67/2.17 GHz with 3‐dB fractional bandwidths of 18.0%/12.9%, less than 0.73/1.24 dB insertion losses, better than 16.5/15 dB return losses, and higher than 35.9 dB isolation.
Dc‐link voltage stability analysis technique for hybrid five‐phase open‐end winding drives

The dc-link voltage stability for a hybrid five-phase open-end winding (OeW) drive operating under carrier-based pulse-width modulation is studied. The drive consists of a five-phase induction machine, supplied using one three-level and one two-level voltage source inverter. This configuration is analysed for the case of isolated dc-link rails, while the dc-link voltage ratio is considered as an additional degree of freedom. It is demonstrated that different dc-link voltage ratios lead to the different overall number of voltage levels across stator windings. Modulation strategies are investigated and their performances are analysed from the dc-link voltages stability point of view. An analytical method for dc-link voltage stability analysis is presented. Results show that the four-level configuration always leads to stable dc-link voltages, regardless of the modulation strategy. On the other hand, if the six-level configuration is combined with modulation strategies that lead to optimal harmonic performance, not all dc-link capacitor voltages will be in the balance depending on the operating conditions.
Robust ZAD Sliding Mode Control for an 8-Phase Step-Down Converter

This paper describes the design, robustness analysis, and implementation of a zero average dynamics sliding mode control (ZAD–SMC) for a multiphase step-down converter. The ZAD–SMC operates at fixed switching frequency and allows to implement an interleaving technique providing current-ripple cancellation at the converter output. Moreover, the proposed control structure, which is based on a master–slave strategy, includes an equalization technique guaranteeing current sharing among the phases and avoiding undesirable power unbalance. Additionally, a stability analysis considering unmatched losses in the converter phases shows that the design provides asymptotic stability for the overall load range. The controllers are implemented in an FPGA, and all the expected features, such as fast transient response, robustness, fixed switching frequency, interleaving, and current equalization are sustained by the experimental results obtained from using a 1.5-kW prototype.
The emergence of 3D bioprinting in organ-on-chip systems

Understanding complex cell–cell interactions and physiological microenvironments is critical for the development of new therapies for treating human diseases. Current animal models fail to accurately predict success of therapeutic compounds and clinical treatments. Advances in biomaterials, engineering, and additive manufacturing have led to the development of printed tissues, lab-on-chip devices, and, more recently, organ-on-chip systems. These technologies have promising applications for the fabrication of more physiologically representative human tissues and can be used for high-throughput testing of human cells and organoids. These organ-on-chip systems can be fabricated with integrated fluidics to allow for the precise control and manipulation of cellular microenvironments with multiple cell types. Further control over these cellular environments can be achieved with bioprinting, allowing for three-dimensional (3D) printing of multiple materials and cell types to provide precisely controlled structures manufactured in a one-step process. As cell behavior is highly dependent on the physical and chemical properties of the environment, the behavior of cells in two-dimensional and 3D culture systems varies drastically. Providing devices that can support long-term cell culture and controlled stimulation of 3D culture systems will have a profound impact on the study of physiological processes and disease, as well as the development of new therapies. This review highlights recent advances in organ-on-chip systems and 3D bioprinting techniques for the development of in vitro physiological models.
Fuzzy Static Output Feedback Control for Path Following of Autonomous Vehicles With Transient Performance Improvements

This paper provides a new solution for path following control of autonomous ground vehicles. <inline-formula> <tex-math notation="LaTeX">$\mathcal {H}_{2}$ </tex-math></inline-formula> control problem is considered to attenuate the effect of the road curvature disturbance. To this end, we formulate a standard model from the road-vehicle dynamics, the <italic>a priori</italic> knowledge on the road curvature, and the path following specifications. This standard model is then represented in a Takagi–Sugeno fuzzy form to deal with the time-varying nature of the vehicle speed. Based on a static output feedback scheme, the proposed method allows avoiding expensive vehicle sensors while keeping the simplest control structure for real-time implementation. The concept of <inline-formula> <tex-math notation="LaTeX">$\mathcal {D}-$ </tex-math></inline-formula>stability is exploited using Lyapunov stability arguments to improve the transient behaviors of the closed-loop vehicle system. In particular, the physical upper and lower bounds of the vehicle acceleration are explicitly considered in the design procedure via a parameter-dependent Lyapunov function to reduce drastically the design conservatism. The proposed <inline-formula> <tex-math notation="LaTeX">$\mathcal {H}_{2}$ </tex-math></inline-formula> design conditions are expressed in terms of linear matrix inequalities (LMIs) with a single line search parameter. The effectiveness of the new path following control method is clearly demonstrated with both theoretical illustrations and hardware experiments under real-world driving situations.
Touch-and-Go: Interior Tactile Communication in Armored Fighting Vehicles

In armored fighting vehicles (AFVs), the vehicle commander (VC) and crew communicate through an audio system that all crew members inside the AFV can hear. This can be distracting and inconvenient, especially for effective communication between the VC and the driver. We assessed the feasibility and usability of a tactile system for direct communication between the VC and the driver in addition to (or instead of) the existing auditory system. Field experiment results show that, with or without auditory commands, tactile cues can be utilized to direct AFV drivers during operational tasks. Hence, specific design and implementation of a tactile interface should be considered for internal communication traffic.
Bridgeless Cuk-Derived Single Power Conversion Inverter With Reactive-Power Capability

This paper presents a bridgeless Cuk-derived single power conversion inverter with reduced number of power components, which has reactive-power capability. The secondary diode of the conventional unfolding-type Cuk inverter is integrated into one of the secondary-side switches in the bridgeless Cuk-derived configuration, which reduces the number of active-power components. A modulation technique is developed to provide a current path during reverse power flow; this technique enables operations under unity and nonunity power factors. A repetitive controller coupled with a linear feedback controller and a feed-forward controller are used to achieve accurate output current tracking under the harsh control environment. Driving the diode-integrated switch in synchronous rectification mode provides higher power conversion efficiency than that under diode-based secondary side rectification. Circuit operation and design guidelines of the bridgeless Cuk inverter are presented in detail. A 500-VA prototype inverter was fabricated to demonstrate the desirable performance of the bridgeless Cuk-derived inverter.
Cultural Competence: Toward a More Robust Conceptualisation

ABSTRACT This article revisits LIS literature about cultural competence. It is not the prominent topic it was but is still considered important for addressing diversity, and is still criticized for obscuring racism and power structures in librarianship and society. Articles published in the last four years suggest, however, that library and information studies educators are teaching to engage with these issues. The cultural competence conceptual framework, specifically the environmental domain, can be recast to incorporate engagement with race and power. This more robust framework would enable culturally competent professionals to do more than accommodate difference.
Big Data Classification Using Distributed Optimized Hoeffding Trees

Large usage of social media, online shopping or transactions gives birth to voluminous data. Visual representation and analysis of this large amount of data is one of the major research topics today. As this data is changing over the period of time, we need an approach which will take care of velocity of data as well as volume and variety. In this paper, author has proposed a distributed method which will handle three dimensions of data and gives good results as compared to other method. Traditional algorithms are based on global optima which are basically memory resident programs. Our approach which is based on optimized hoeffding bound uses local optima method and distributed map-reduce architecture. It does not require copying whole data set onto a memory. As the model build is frequently updated on multiple nodes concurrently, it is more suitable for time varying data. Hoeffding bound is basically suitable for real time data stream. We have proposed very efficient distributed map-reduce architecture to implement hoeffding tree efficiently. We have used deep learning at leaf level to optimize the hoeffding tree. Drift detection is taken care by the architecture itself no separate provision is required for this. In this paper, with experimental results it is proved that our method takes less learning time with more accuracy. Also distributed algorithm for hoeffding tree implementation is proposed.
OPEC: Daily Load Data Analysis Based on Optimized Evolutionary Clustering

Customers’ electricity consumption behavior can be studied from daily load data. Studying the daily load data for user behavior pattern analysis is an emerging research area in smart grid. Traditionally, the daily load data can be clustered into different clusters, to reveal the different categories of consumption. However, as user’s electricity consumption behavior changes over time, classical clustering algorithms are not suitable for tracing the changes, as they rebuild the clusters when clustering at any timestamp but never consider the relationship with the clusters in the previous state. To understand the changes of consumption behavior, we proposed an optimized evolutionary clustering (OPEC) algorithm, which optimized the existing evolutionary clustering algorithm by joining the Proper Restart (PR) Framework. OPEC relied on the basic fact that user’s energy consumption behavior would not abruptly change significantly, so the clusters would change progressively and remain similar in adjacent periods, except for an emergency. The newly added PR framework can deal with a situation where data changes dramatically in a short period of time, and where the former frameworks of evolutionary clustering do not work well. We evaluated the OPEC based on daily load data from Shanghai, China and the power load diagram data from UCI machine learning repository. We also carefully discussed the adjustment of the parameter in the optimized algorithm and gave an optimal value for reference. OPEC can be implemented to adapt to this situation and improve clustering quality. By understanding the changes of the users’ power consumption modes, we can detect abnormal power consumption behaviors, and also analyze the changing trend to improve the operations of the power system. This is significant for the regulation of peak load in the power grid. In addition, it can bring certain economic benefits to the operation of the power grid.