Proper Interface Research Articles

Effects of Ti2SnC MAX phase reinforcement content on the properties of copper matrix composite produced by friction stir back extrusion process

In this present work, the effect of Ti2SnC content on the microstructure, mechanical, electrical and wear properties of friction stir back extrusion (FSBE) processed Cu–Ti2SnC composite wire was investigated. The FSBE process was performed on copper matrix composite with 0–30 vol% of Ti2SnC reinforcement. The results show that by increasing the content of the Ti2SnC phase the hardness of the composite increased and reached 280.51 HV for composite containing 30 vol% Ti2SnC phases. The proper interface bonding was obtained in the composite containing 1 and 5 vol% Ti2SnC phases. The highest yield strength, ultimate tensile strength and wear resistance were obtained in the composite containing 5 vol% Ti2SnC phases due to the proper interface bonding. Also, the highest electrical conductivity (95.67% IASC) was obtained in a composite containing 1 vol% Ti2SnC phases. By increasing Ti2SnC phases higher than 5 vol% discontinuities between the Ti2SnC phase particles and the Cu matrix increased and result in decreasing strength and electrical conductivity of copper matrix composite.

Graphene Metamaterial 3D Conformal Coating for Enhanced Light Harvesting

Silicon (Si) photovoltaic devices present possible avenues for overcoming global energy and environmental challenges. The high reflection and surface recombination losses caused by the Si interface and its nanofabrication process are the main hurdles for pursuing a high energy conversion efficiency. However, recent advances have demonstrated great success in improving device performance via proper Si interface modification with the optical and electrical features of two-dimensional (2D) materials. Firmly integrating large-area 2D materials with 3D Si nanostructures with no gap in between, which is essential for optimizing device performance, has rarely been achieved by any technique due to the complex 3D morphology of the nanostructures. Here we propose the concept of a 3D conformal coating of graphene metamaterials, in which the 2D graphene layers perfectly adapt to the 3D Si curvatures, leading to a universal 20% optical reflection decrease and a 60% surface passivation improvement. In a further application of this metamaterial 3D conformal coating methodology to standard Si solar cells, an overall 23% enhancement of the solar energy conversion efficiency is achieved. The 3D conformal coating strategy could be readily extended to various optoelectronic and semiconductor device systems with peculiar performance, offering a pathway for highly efficient energy-harvesting and storage solutions.

In-plane graphene incorporated borocarbonitride: Directional utilization of disorder charge via micro π-conjugated heterointerface for photocatalytic CO2 reduction

Despite the potential of hexagonal boron carbon nitride (h-BCN) with a unique graphite-like structure in the field of photocatalysis, the serious photocarrier recombination caused by disordered charge transfer has limited its practical application. In this work, we propose a conceptual design of in-plane heterostructures consisting of graphene sheet and non-phase-separated borocarbonitride (Gsheet–BCN) with micro π-conjugated heterointerface for directional utilization of disorder charge. The obtained G150–BCN exhibits 10 times longer carrier decay lifetime (16.82 ns) and 3.7 times higher CO yield (51.14 μmol g−1 h−1) than pristine BCN. It was confirmed by systematical characterizations and theoretical calculations that the micro π-conjugated heterointerface enables the directional transport of photo-induced electrons from BCN to graphene domains, resulting in enhanced carrier separation and CO2 reduction efficiency. This work developed a unique synthetic route to the design and construction of heterojunction with proper interface and rational electronic structure for efficient separation of photoexcited charges.

Evaluation of Differentiated Services Policies in Multihomed Networks Based on an Interface-Selection Mechanism

Quality of service metrics and differentiated service mechanism policies are the most important criteria to deliver essential Internet requirements, especially during user handover, due to the rapid growth of users, multimedia applications, and traffic. DiffServ routers provide per-hop behaviors to manage traffic for services, whereas their policies have been applied to several types of Internet traffic, such as hypertext transfer protocol, file transfer protocol, and content-based routing. Multihoming aims to improve the reliability, scalability, and performance of data communications networks. This paper evaluated DiffServ various policies compared in a systematic manner (in two stages) over the multihomed networks to utilize and adopt the best policy for communicating packets, and enhanced the overall performance in terms of throughput, end-to-end latency, and processing time. Moreover, the paper introduced an interface-selection technique for multihomed nodes to select a proper interface, which provides the best services and links the behaviors that this interface yields. The overall results showed how the introduced multihoming-based interface-selection mechanism managed to maintain communication with the multihomed node. Furthermore, our results showed that the DiffServ time-sliding window with a three-color marking policy achieved the best system performance compared with the remaining policies.

Very Simple System for Walking-Speed Measurement in Geriatric Patients

Walking speed in geriatric patients is an important index for inferring the patient’s state of health and estimating the success rate of some surgical procedures. Although different solutions for monitoring the gait of a subject exist in scientific literature and on the market, there is a need for a system that is very simple, especially to wear, considering that elderly subjects often have movement difficulties. For this reason, we investigated the possibility of using a standard miniaturized wireless microphone, that can be easily attached to patients’ clothes by means of a clip, as the sole sensing device to be worn by the test subject. A transceiver, a sound card and a PC complete the system, which turns out to be quite simple to be set up and use, thanks to a proper graphic user interface that controls its entire operation. The system essentially tracks the position of the test subject over time by measuring the propagation times of repeated sound pulses from the speaker to the microphone. To avoid hearing discomfort, the frequency of the pulses is chosen at the higher end of the audio spectrum, so that they are essentially undetectable by adults. The measurement range is in excess of 6 m, that is sufficient for the standard 4 m walking-speed test. Tests performed in a laboratory environment have confirmed the effectiveness of the approach we propose.

Electrical characteristics investigation of ferroelectric memories using stacked and mixed hafnium zirconium oxides

• Ferroelectric characteristics of mixed and stacked HfZrO devices were investigated. • Stacked HfZrO device showed a much stronger ferroelectricity than mixed one. • A surface nitrogen plasma treatment can alleviate ferroelectric domain pinning. • Nitrogen incorporation into stacked HfZrO further improved the endurance cycling. In this work, we investigate ferroelectric characteristics of hafnium zirconium oxide (HfZrO) metal-ferroelectric-metal (MFM) devices with mixed and stacked film structure. The experimental results reveal that the stacked HfZrO MFM device has a lower dynamic leakage and stronger ferroelectric polarization value of approximately 27.3 μC/cm 2 , which is much higher than 17.5 μC/cm 2 measured from mixed HfZrO MFM device. From endurance cycling test, we also confirm that the stacked HfZrO MFM capacitor with a remote nitrogen plasma treatment featuring a large initial hysteresis window can achieve a stable operation up to 10 8 cycles at an operating voltage of 2.5 V, which is even longer than that of mixed HfZrO MFM capacitor by one order of magnitude. Therefore, the stacked MFM structure with proper interface engineering provides a promising approach for the process integration of ferroelectric memory under the comprehensive consideration of device performance and endurance.

The PIVO process for identifying vulnerabilities impact for organisation risks: An automated solution

Risk management (RM) and vulnerability management (VM) are both essential cyber security domains. They are often managed independently without a proper interface to provide context information to each other and share information. This paper proposes an approach to connect RM and VM processes based on data standardisation through referential and automation to relate vulnerabilities to operational risk scenarios. The focus is mainly on the identification of the referential and their added value to complement a method described in a previous paper.

Spin Pumping through Different Spin-Orbit Coupling Interfaces in β-W/Interlayer/Co2FeAl Heterostructures.

Spin pumping has been considered a powerful tool to manipulate the spin current in a ferromagnetic/nonmagnetic (FM/NM) system, where the NM part exhibits large spin-orbit coupling (SOC). In this work, the spin pumping in β-W/Interlayer (IL)/Co2FeAl (CFA) heterostructures grown on Si(100) is systematically investigated with different ILs in which SOC strength ranges from weak to strong. We first measure the spin pumping through the enhancement of effective damping in CFA by varying the thickness of β-W. The damping enhancement in the bilayer of β-W/CFA (without IL) is found to be ∼50% larger than the Gilbert damping in a single CFA layer with a spin diffusion length and spin mixing conductance of 2.12 ± 0.27 nm and 13.17 ± 0.34 nm-2, respectively. Further, the ILs of different SOC strengths such as Al, Mg, Mo, and Ta were inserted at the β-W/CFA interface to probe their impact on damping in β-W/ILs/CFA. The effective damping reduced to 8% and 20% for Al and Mg, respectively, whereas it increased to 66% and 75% with ILs of Mo and Ta, respectively, compared to the β-W/CFA heterostructure. Thus, in the presence of ILs with weak SOC, the spin pumping at the β-W/CFA interface is suppressed, while for the high SOC ILs effective damping increased significantly from its original value of β-W/CFA bilayer using a thin IL. This is further confirmed by performing inverse spin Hall effect measurements. In summary, the transfer of spin angular momentum can be significantly enhanced by choosing a proper ultrathin interface layer. Our study provides a tool to increase the spin current production by inserting an appropriate thin interlayer which is useful in modifying the heterostructure for efficient performance in spintronics devices.

Kirigami-Inspired Pressure Sensors for Wearable Dynamic Cardiovascular Monitoring.

Continuously and accurately monitoring pulse-wave signals is critical to prevent and diagnose cardiovascular diseases. However, existing wearable pulse sensors are vulnerable to motion artifacts due to the lack of proper adhesion and conformal interface with human skin during body movement. Here, a highly sensitive and conformal pressure sensor inspired by the kirigami structure is developed to measure the human pulse wave on different body artery sites under various prestressing pressure conditions and even with body movement. COMSOL multiphysical field coupling simulation and experimental testing are used to verify the unique advantages of the kirigami structure. The device shows a superior sensitivity (35.2mV Pa-1 ) and remarkable stability (>84000 cycles). Toward practical applications, a wireless cardiovascular monitoring system is developed for wirelessly transmitting the pulse signals to a mobile phone in real-time, which successfully distinguished the pulse waveforms from different participants. The pulse waveforms measured by the kirigami inspired pressure sensor are as accurate as those provided by the commercial medical device. Given the compelling features, the sensor provides an ascendant way for wearable electronics to overcome motion artifacts when monitoring pulse signals, thus representing a solid advancement toward personalized healthcare in the era of the Internet of Things.

ZnO/NiO heterostructures with enhanced photocatalytic activity obtained by ultrasonic spraying of a NiO shell onto ZnO nanorods

Degradation of organic pollutants such as methylene blue (MB) from water resources is currently of particular interest. Employment of a heterojunction device with optimized layer properties and proper interface engineering can enhance the photocatalytic performance by taking advantage of efficient charge separation. In this work, we develop an efficient photocatalytic system for the MB degradation based on ZnO nanorod (ZnONR)/NiO core-shell heterostructure with an optimized chemical and electronic structure for achieving record MB degradation efficiency of ∼70 %. ZnONR were grown by hydrothermal technique, whereas homogeneous crystalline NiO thin films were prepared by a robust and easy for up-scaling method of ultrasonic spray pyrolysis (USP). The optimum preparation conditions of photocatalytically efficient ZnONR/NiO heterostructures imply NiO film deposition from two USP cycles at 500 °C followed by air annealing heterostructures at 600 °C. The photocatalytic performance of ZnONR/NiO core-shell structure was investigated in comparison to counterpart layers and ZnO/NiO bilayer system. Chemical composition and band alignment at the ZnONR/NiO interface were investigated by X-ray photoelectron spectroscopy, Kelvin probe and photoelectron yield spectroscopy. Current transport studies indicated the presence of built-in electric field at the n-ZnO/p-NiO heterointerface responsible for the enhanced photocatalytic activity and based on this the degradation mechanism of MB is discussed.

HEART DISEASE PREDICTION USING MACHINE LEARNING

There is a great saying that is “Health is the most valuable Wealth”,this is because people may have great ideas, money and many things but everything can be done only when our health supports us. The main motto of our project is “Prevention is always better than the cure”.In this project we use the technology for early detection of heart diseases. These days whole world people are dying because of the hear diseases and even in many cases these are sudden deaths, So in this project we design a machine learning model which can predict the heart diseases. This machine learning model predicts whether a person can have a heart disease or not based on the information or the symptom the person enters into the system. Here we are using the machine learning algorithms like the Decision Tree, Random Forest, KNN algorithms for precise prediction of the result. Every project is incomplete without a proper interface to the entire model so for the user interface here we are using the Tkinter Interface. For the training purpose we are using a predefined dataset which we get it from the kaggle website. So in this way we construct our entire model.

Effects of Cu, Cu3Sn, Cu6Sn5 on Interfacial Properties between Cu–Sn Alloys and Diamond

The interfacial properties of the Cu‐based intermetallic compounds and diamond abrasives remain a challenging task in fabricating high‐performance Cu‐based diamond‐grinding wheels and, herein, the effects of Cu, Cu3Sn, and Cu6Sn5 on interfacial properties between Cu–Sn alloys and diamond (111) are aimed to be investigated. The stable three‐layer slab models are established based on density‐functional theory (DFT). The interface energy, electronic density, electronic localization function (ELF), and density of state (DOS) are calculated and analyzed. It is shown that Cu6Sn5 is a critical intermetallic compound to affect interfacial properties. The degree of hybridization of the Cu6Sn5 (100)/diamond (111) model is the strongest among all models, which leads to lower interface energy and better wettability. Herein, theoretical guidance for fabricating Cu‐based diamond‐grinding wheels by adjusting the sintering temperature and formula of the Cu‐based binder to achieve the proper interface strength are provided.

A Survey on Evaluating Usability of Visual Studio

Programing plays an important role in Computer Science (CS) students during their degrees. The study was conducted to evaluate the Microsoft visual studio programming tool to find out usability issues and provides the recommendations. The main goal of this research was to initiate dialog in the CS community to address usability issues can provide better interface to improve the usability of such kind of programming framework. It has been examined by evaluating qualitatively and quantitatively the interface with novice and expert users. Quantitative assessment is done in university with the help of usability testing in order to explore the usability problems of programming tool Visual Studio with the help of quantitative evaluation where satisfaction level is measured. System Usability Scale (SUS) questionnaire and After Scenario Questionnaire (ASQ) is used for the opinion of the participants after usability testing that help to improve the interface of the tool. Qualitative evaluation-usability inspection technique termed as heuristic evaluation is used by Nielson heuristics to improve the usability of the interface. Experiment was conducting at Bahria University Lahore campus in programing course lab under controlled environment. Overall SUS score was 48% of first semester bachelors of information technology (BSIT) students that is below the threshold satisfaction value which recommends that usability issues should be identified. Experts evaluated the interface by 10 Nielson heuristics and highlighted major and, minor issues. Proper interface was suggested by the experts to produce better result.

Interface engineering of Ta3N5 thin film photoanode for highly efficient photoelectrochemical water splitting

Interface engineering is a proven strategy to improve the efficiency of thin film semiconductor based solar energy conversion devices. Ta3N5 thin film photoanode is a promising candidate for photoelectrochemical (PEC) water splitting. Yet, a concerted effort to engineer both the bottom and top interfaces of Ta3N5 thin film photoanode is still lacking. Here, we employ n-type In:GaN and p-type Mg:GaN to modify the bottom and top interfaces of Ta3N5 thin film photoanode, respectively. The obtained In:GaN/Ta3N5/Mg:GaN heterojunction photoanode shows enhanced bulk carrier separation capability and better injection efficiency at photoanode/electrolyte interface, which lead to a record-high applied bias photon-to-current efficiency of 3.46% for Ta3N5-based photoanode. Furthermore, the roles of the In:GaN and Mg:GaN layers are distinguished through mechanistic studies. While the In:GaN layer contributes mainly to the enhanced bulk charge separation efficiency, the Mg:GaN layer improves the surface charge inject efficiency. This work demonstrates the crucial role of proper interface engineering for thin film-based photoanode in achieving efficient PEC water splitting.

Augmented reality-based border management

A proficient border management has typically been tied to its capability to support information structuring and to make exchanges from the distributed sources. The lack of a proper access interface to information at the right time and the right place to conduct various activities. Augmented reality (AR) has been proposed as an efficient interface in order to improve the efficiency and the effectiveness of activities in the real world. There has only been a limited amount of research that has evaluated the effectiveness and usability of AR in the border management domain. This research aims to evaluate the effectiveness of border management and AR system integration to enhance the activities’ efficiency through improving the information retrieval process. The system development steps were adopted to design, develop, and evaluate the border management AR (BM AR) system. The system contains three AR services that include pointing to border objects, showing the borderline, and locating border objects. The system also integrates the information from different resources in an interoperable way using GIS web services. The results revealed the effectiveness of using AR for border activities, which can reduce the operating costs and effectively, access the required information for doing different activities in the border field.

Machine Learning Based Transient Stability Emulation and Dynamic System Equivalencing of Large-Scale AC-DC Grids for Faster-Than-Real-Time Digital Twin

Modern power systems have been expanding significantly including the integration of high voltage direct current (HVDC) systems, bringing a tremendous computational challenge to transient stability simulation for dynamic security assessment (DSA). In this work, a practical method for energy control center with the machine learning (ML) based synchronous generator model (SGM) and dynamic equivalent model (DEM) is proposed to reduce the computational burden of the traditional transient stability (TS) simulation. The proposed ML-based models are deployed on the field programmable gate arrays (FPGAs) for faster-than-real-time (FTRT) digital twin hardware emulation of the real power system. The Gated Recurrent Unit (GRU) algorithm is adopted to train the SGM and DEM, where the training and testing datasets are obtained from the off-line simulation tool DSAToolsTM/TSAT®. A test system containing 15 ACTIVSg 500-bus systems interconnected by a 15-terminal DC grid is established for validating the accuracy of the proposed FTRT digital twin emulation platform. Due to the complexity of emulating large-scale AC-DC grid, multiple FPGA boards are applied, and a proper interface strategy is also proposed for data synchronization. As a result, the efficacy of the hardware emulation is demonstrated by two case studies, where an FTRT ratio of more than 684 is achieved by applying the GRU-SGM, while it reaches over 208 times for hybrid computational-ML based digital twin of AC-DC grid.

Construction of Interfacial Electric Field via Dual-Porphyrin Heterostructure Boosting Photocatalytic Hydrogen Evolution.

A dual-porphyrin heterostructure is successfully constructed by coupling tetrakis (4-carboxyphenyl) zinc porphyrin (ZnTCPP) with tetrakis (4-hydroxyphenyl) porphyrin (THPP). The high photocatalytic H2 evolution rate of 41.4mmol h-1 g-1 is obtained for ZnTCPP/THPP under full spectrum, which is ≈5.1 and ≈17.0 times higher than that of pure ZnTCPP and THPP, respectively. The significantly enhanced activity is mainly attributed to the giant interfacial electric field formed between dual porphyrins, which greatly facilitates efficient charge separation and transfer. Meanwhile, similar conjugated structures of dual porphyrins also provide proper interface match and decrease interface defects, thus inhibiting the recombination of photoproduced carriers. By rationally combining the appropriate band structures and high-quality interfacial contact of dual porphyrins, this work provides a fresh insight into the interfacial electric field construction to improve the photocatalytic performance.

Integrated pricing strategy for coordinating load levels in coupled power and transportation networks

The increasing popularity of electric vehicles and the development of dynamic wireless charging technology have strengthened the integration between the power system and transportation system. To coordinate the load levels of the coupled power distribution network and transportation network, we propose an integrated pricing strategy including road tolls and charging prices, which depend on the road traffic load rate in the transportation network and the bus load rate in the power distribution network, respectively. To accurately model the interdependency between the power distribution network and the transportation network, a proper interface equation is proposed. Considering data privacy, we adopt a distributed optimization. Furthermore, we present a power allocation strategy based on model predictive control to meet the charging requirements of different EVs. Correspondingly, the above ideas form a two-layer optimization strategy. Based on the integrated pricing strategy, the upper layer aims to minimize the power generation cost and transportation travel cost, while balancing the load levels. The lower layer distributes charging power to different EVs based on the total power demand from the interface equation between the power distribution network and the transportation network. Numerical results demonstrate the effectiveness of the proposed integrated pricing strategy for coordinating load levels in coupled networks.

Tuning the kinetics of binder-free ammonium vanadate cathode via defect modulation for ultrastable rechargeable zinc ion batteries

Reasonable nanostructure design and proper interface engineering are of great significance for improve the low conductivity and slow kinetic process of vanadium-based compounds. Herein, we report an advanced stainless steel (SS) supported oxygen-rich vacancy (NH4)2V10O25·8H2O (Od-NVO-SS-2) cistern-like nanobelt cathode with broadened interlayer spacings and ultrafast reaction kinetic. As expected, as cathode of aqueous zinc-ion battery (AZIB), the Od-NVO-SS-2 electrode shows high capacity of 331.4 mAh g−1 (0.3 A g−1), excellent rate performance and satisfactory cyclic stability (78.3 mAh g−1 at 4.8 A g−1 after 7500 cycles). In addition, a flexible quasi-solid-state (FQSS) Od-NVO-SS-2//Zn battery was studied, which showed almost the same excellent performance in various bending states, and even in a variety of harsh conditions water immersion, hammering, washing, loading, drilling and cutting, it can also perform well. In this work, the projected density of states (PDOS) calculation results shows that the defects improve the conductivity due to the increase of carrier concentration, which is beneficial to improve the reaction kinetics and endow the ability to store Zn2+ ions rapidly. The smaller Zn2+ ion adsorption energy of Od-NVO-SS-2 calculated by density functional theory (DFT) also indicates that the introduction of defects is conducive to increasing the active sites of electrode materials and contributing additional capacity. In addition, that active material is directly grown on the current collector, thereby effectively avoiding shedding in the circulation process. Importantly, the Zn2+ storage mechanism in Od-NVO-SS-2 is successfully revealed. This defect engineering has reference significance for the design of advanced electrode materials with excellent properties.

Fast Response of kW-Class Vanadium Redox Flow Batteries

An experimental and numerical time-domain analysis of the early electric response of two kw-class Vanadium Redox Flow Batteries (VRFBs) under different state of charge, electrolyte flow and load is presented. The numerical analysis resorted to an equivalent circuit whose parameters were identified from electrochemical impedance spectroscopy measurements. Two discharge modes were investigated: natural discharge on resistors, to detect the spontaneous battery evolution, and discharge driven by an electronic load, forcing a galvanostatic evolution. Two different timescales were investigated in each discharge modes, namely 20 ms and 120 s. The millisecond mode revealed stack current and voltage swings in the is very short timescale (7 ms). This behavior suggests an initial turbulent electrochemical phase involving successive activations of vanadium species associated with coordination complexes at the positive electrode. In the latter mode, experimental and numerical results revealed that both stacks reached steady conditions much faster, in few hundreds of milliseconds. These results demonstrate that vanadium redox flow batteries are eligible for fast services in 50–60 Hz grids, provided the discharge current is driven in a current-source mode by proper interface power electronics. To the best of our knowledge, this is the first time that the fast time-domain response of large VRFBs is reported.