Large Amount Of Load Research Articles

Improvement on interfacial properties of CuW and CuCr bimetallic materials with high-entropy alloy interlayers via infiltration method

Abstract In order to achieve metallurgical bonding in the form of solid solution at the Cu/W interface and avoid the formation of intermetallic compounds, the novel high entropy alloys (HEAs) were designed on the basis of the mature high entropy alloy criteria. The CuCrCoFeNi x Ti high entropy alloys interlayers were applied to weld the CuW and CuCr bimetals by sintering–infiltration technology. Scanning electron microscope, energy dispersive spectrometry, and X-ray diffraction were used to explore the interfacial microstructure evolutions and strengthening mechanism of CuW/CuCr joints with applied HEA interlayers. The interfacial characterization results show that HEAs were diffused and dissolved into bimetallic materials, and a diffusion solution layer of 2–3 μm thickness was formed at the Cu/W phase interface, and there is no new phase generated at the CuW/CuCr interface. When CuCrCoFeNi1.5Ti interlayer was infiltrated into the CuW/CuCr interface, the electrical conductivity of CuCr side is 71.6%IACS, and the interfacial tensile strength reaches 484.5 MPa. Compared with the CuW/CuCr integral material without interlayer, the interfacial bonding strength is increased by 43.1%. And the SEM fracture morphology presents a larger amount of cleavage fractures of W particles. It indicates the appropriate solid solution layer on edge of W skeletons formed at the Cu/W phases interface. The Cu/W phase interface is strengthened, and it can effectively transfer and disperse the external load. Tungsten phase with higher elastic modulus endures a large amount of load, resulting in enhancing the CuW/CuCr interfacial bonding strength. When CuCrCoFeNi2Ti high entropy alloy interlayer was applied, the W skeleton near the CuW/CuCr interface was eroded, the imperfect W skeleton cannot withstand the tensile load effectively, resulting in decrease in the CuW/CuCr interfacial bonding strength. In the interfacial fracture, appears some fragmentations of W particles, and fewer W particles occur at the cleavage fracture.

A study on: Design and fabrication of E-glass fiber reinforced IPN composite chain plates for low duty chain drives

Chains are used in mechanical drives to carry away a large amount of load from one drive to another drive. Therefore the material of the chain should be able to withstand tensile loads and have high stiffness. Usually the chains are made up of iron. But the disadvantage is that iron consumes more weight and it is more expensive. In order overcome the difficulties, the chain plates are fabricated with the help of Interpenetrating Polymer Networks (IPNs) resins (with vinyl ester and polyurethane) and reinforced E-glass fiber composite material. The main aim of the project is to study and analyze the physical properties and structural properties of the plate material varying proportions of IPN resin such as 100% vinyl ester (VEU) with 0% polyurethane (PU), 90% VEU and 10% PU, 80% VEU and 20% PU, 70% VEU and 30% PU, 60% VEU and 40% PU. Finally a fatigue tests is conducted for different plates for different resin proportion and comparison is made between the characteristics of fabricated chain plate with that of iron material. Because of their dependability and durability, glass fibre reinforced composite link plates are used in material handling equipment, agricultural machinery, manufacturing conveyors, and automobile manufacture.

Fabrication of dual self-healing silane nanocomposite for efficient corrosion protection of aluminum alloy

1,5-naphthalenediol (ND) inhibitor loaded hollow CeO2 nanoparticles were incorporated into superhydrophobic silane coating on aluminum alloy for corrosion protection. The hollow CeO2 nano-carrier exhibited a large loading amount of 23.5 wt%. The corrosion protection and self-healing performance was investigated by using electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) in 3.5 wt% NaCl solution. EIS result indicated that the constructed silane/CeO2@ND composite coating significantly enhanced the corrosion resistance and the inhibition efficiency was 97.9%. Meanwhile, the localized corrosion was remarkably suppressed from EN measurements. Moreover, the silane/CeO2@ND composite coating exhibited an excellent chemical and mechanical stability and self-healing ability due to the synergistic effect of incorporated inhibitive CeO2 nanoparticles and the loaded effective ND inhibitor.

Facile synthesis of pure silicon zeolite-confined silver nanoparticles and their catalytic activity for the reduction of 4-nitrophenol and methylene blue

Supported noble metal heterogeneous catalysts have been proven to be effective for the treatment of toxic organic pollutants. Herein, ultrafine Ag nanoparticles (NPs) with an average size of approximately 4.37 nm was decorated on the surface of pure silicon zeolite nanoparticle (PSZN) and confined in pore channels through a low-cost and environmentally friendly in-situ reduction strategy. The prepared Ag/PSZN nanocomposites showed ultrahigh catalytic activity for the reduction of 4-nitrophenol (4-NP) (∼200 s, 17.29 × 10-3 s−1) and methylene blue (MB) (∼4 min, 76.53 × 10-2 min−1), which outperforms the majority of the previously reported Ag-based catalysts. The excellent catalytic performance is due to the large loading amount (Wt = 16.8 %) and ultrasmall size of Ag NPs, which provides abundant active sites. Moreover, it showed outstanding recyclability of 93 % and 86 % removal of 4-NP and MB, respectively, after 10 cycle reactions, and stability after 300 days of storage at room temperature. This work offers new insights into the fabrication of Ag-based catalysts for efficiently removing organic pollutants from aqueous solutions.

Utilization of Electric Vehicle Grid Integration System for Power Grid Ancillary Services

Electric vehicle grid integration (EVGI) is one of the most important parts of transportation electrification. However, large-scale EV charging/discharging can have an adverse effect on the distribution grid, due to a large amount of load being drawn from or fed back to the power grid. Additionally, the power electronics used in the grid interaction may impose additional complications, such as voltage and frequency deviation, harmonic distortion, etc. With proper control scheme designs for the grid-connected inverters, such complications can be mitigated, and several grid ancillary services, such as voltage and frequency support, reactive power support, and harmonic mitigation, can be facilitated from large-scale EVGI. In this study, a large-scale EVGI system is developed where the vector control implementation of a grid-connected inverter in the d-q reference frame is presented for providing different grid ancillary services using the EVGI system. The EVGI system is operated in different control modes to ensure multiple ancillary services of the power grid. The study is supported by the electromagnetic transient simulation performed in Matlab/Simulink of a large-scale EVGI system. The simulation shows that with the proper control mechanism of grid-connected inverters, EVGI can be used to provide several useful grid ancillary services.

Fabrication of a novel Ti3C2-modified Sb-SnO2 porous electrode for electrochemical oxidation of organic pollutants

Sb-SnO2 is an appealing electrode for degrading organic pollutants in wastewater treatment, albeit further modifications are needed for its inefficient electrochemical oxidation capacity. In this work, we prepared Ti3C2-modified Sb-SnO2 electrode by electrodeposition technology. High-conductive MXene matrix regulated the Sb-Sn alloy nucleation process to decrease its domain size during deposition and generated pores during the annealing process. When introducing 20 mg MXene into the electrolyte, the obtained Sb-SnO2 electrode (Ti3C2-20) presented a larger oxygen evolution over-potential (2.32 V vsSCE), increased amount of active sites, and enlarged electrochemical specific surface area (∼4.4-fold) than the unmodified electrode, resulting in a promoted OH generation ability (∼7.4 times). Methylene blue (MB), methyl orange (MO), norfloxacin (NOR), and P-phenylenediamine (PPD) were effectively degraded by the Ti3C2-20 anode with economic energy consumption. Moreover, the Ti3C2-20 electrode also featured a longer lifetime, almost fivefold, than the unmodified Sb-SnO2 electrode due to its larger loading amount and decreased charge transfer resistance. Consequently, this work offers a new perspective for designing efficient and stable porous electrodes to address water pollution issues.

3D Nanoporous Graphene Based Single-Atom Electrocatalysts for Energy Conversion and Storage

ConspectusThis Account will provide an overview and analysis on recent research of 3D nanoporous graphene based single-atom electrocatalysts for energy conversion and storage applications. In order to meet the increasing energy demands and assist in the transition from a global economy that relies heavily on fossil fuels to one that utilizes more renewable energy sources, there is urgent need to develop high-performing electrocatalysts toward renewable energy related reactions. These catalysts are expected to have low overpotentials, high reaction selectivity, long cycling stability, and, importantly, lower materials costs to address the challenges of traditional nanoparticulate noble metal catalysts. One approach to conquering a transition of such scale is the use of single-atom electrocatalysts which can bring benefits of lowered materials cost, increased reaction selectivity, and improved catalytic activity. However, despite some success in recent years there remain challenges such as the stability of single-atom catalysts over time, especially at high operating temperatures and potentials, and the limited loading of single-atom catalysts on a support matrix. This Account will discuss the use of graphene as the support matrix with heavy focus on the progress in developing 3D nanoporous graphene, synthesized by chemical vapor deposition. We will cover how 3D nanoporous graphene possesses a large specific surface area, open porosity, high electric conductivity, and bound geometric and topological defects and analyze how it is emerging as an excellent support material for developing chemically stable and catalytically active single-atom catalysts with a large loading amount and high electrocatalytic efficiency. Additionally, we will highlight the benefits of the presence of topological and geometric defects, from curved graphene in the 3D structure, and how they can bring more chemically active sites, and how, together with chemical dopants, they can improve the catalytic performance, stability, and loading amount of single-atom catalysts via their strong chemical affinity with transition metals and the formation of active M–Nx–Cy (M = transition metals, N-nitrogen, C-carbon) moieties. Furthermore, we will discuss two common methods for fabrication of single-atom catalysts on nanoporous graphene: (1) controlled etching for non-noble and noble metal catalysts and (2) atomic layer deposition for noble metal catalysts. The electrochemical performances of these single-atom catalysts will be reviewed with the applications toward hydrogen evolution reaction, oxygen reduction reaction and oxygen evolution reaction. This Account highlights advances made in solving the challenges of developing 3D nanoporous graphene based single-atom catalysts and the benefits that the new single-atom catalysts can bring to the applications in energy storage and conversion.

Aptasensor for Mycobacterium tuberculosis antigen MPT64 detection using anthraquinone derivative confined in ordered mesoporous carbon as a new redox nanoprobe

Rapid and sensitive tuberculosis (TB) diagnoses remain big challenges to current detection tools. In this work, a sensitive electrochemical aptasensor was constructed for the determination of Mycobacterium tuberculosis antigen MPT64 using a new redox nanoprobe. We found that anthraquinone derivative, anthraquinone-2-carboxylic acid (AQCA), a redox mediator, could be confined in ordered mesoporous carbon material of CMK-3. Due to the large loading amount of AQCA, as well as the confined space and electron transfer promotion effect of CMK-3, the obtained AQCA/CMK-3 nanohybrid with mass ratio of 2:1 showed excellent electroactivity and was employed as a new redox nanoprobe for signal amplification for the first time. Additionally, urchin-like Ce-MOFs were used to load a large amount of deposited gold nanocrystals (dep-Au), leading to dense immobilization of capture probe. The proposed electrochemical aptasensor for MPT64 detection showed a good linear relationship in the range from 100 fg/mL to 10 ng/mL with a low detection limit of 67.6 fg/mL. Besides, the aptasensor was utilized to detect MTP64 in human serum samples for TB diagnosis and presented satisfactory results.

Hierarchical NiCo2S4/ZnIn2S4 heterostructured prisms: High-efficient photocatalysts for hydrogen production under visible-light

Exploring low-cost co-catalyst to ameliorate the photocatalytic activity of semiconductors sets a clear direction for solving energy crisis and achieving efficient solar-chemical energy conversion. In this work, a unique hierarchical hollow heterojunction was constructed by in-situ growing ZnIn2S4 nanosheets on the porous NiCo2S4 hollow prisms through a low temperature solvothermal method, in which NiCo2S4 with semi-metal property acted as non-noble metal co-catalyst. NiCo2S4 co-catalyst was innovatively encapsulated in ZnIn2S4, which not only relieved the light shielding effect caused by the large loading amount of co-catalyst, but also supplied abundant active sites for H2 evolution. The hierarchical hollow heterostructure of NiCo2S4/ZnIn2S4 provided a highly efficient channel for charge transfer. Combining these advantages, NiCo2S4/ZnIn2S4 composite demonstrated excellent photocatalytic activity. In the absence of sacrificial agent, the NiCo2S4/ZnIn2S4 photocatalyst achieved a remarkable improved H2 yield of 0.77 mmol g−1h−1 under visible light irradiation (λ > 400 nm), which is 6.6 times greater than that of ZnIn2S4. Besides, NiCo2S4 even exhibited better performance on the H2 evolution improvement of ZnIn2S4 than precious metal Pt. This work will offer novel insights into the reasonable design of non-noble metal photocatalysts with respectable activity for water splitting.

Single-atom Cu anchored catalysts for photocatalytic renewable H2 production with a quantum efficiency of 56%

Single-atom catalysts anchoring offers a desirable pathway for efficiency maximization and cost-saving for photocatalytic hydrogen evolution. However, the single-atoms loading amount is always within 0.5% in most of the reported due to the agglomeration at higher loading concentrations. In this work, the highly dispersed and large loading amount (>1 wt%) of copper single-atoms were achieved on TiO2, exhibiting the H2 evolution rate of 101.7 mmol g−1 h−1 under simulated solar light irradiation, which is higher than other photocatalysts reported, in addition to the excellent stability as proved after storing 380 days. More importantly, it exhibits an apparent quantum efficiency of 56% at 365 nm, a significant breakthrough in this field. The highly dispersed and large amount of Cu single-atoms incorporation on TiO2 enables the efficient electron transfer via Cu2+-Cu+ process. The present approach paves the way to design advanced materials for remarkable photocatalytic activity and durability.

Wireless Network and Communication in Smart Grid Technology

In this century where everyone is talking about making machine smart, intelligent, it is need of technology to go two steps ahead and make smarter systems upon which humans can rely. Smart Grid is nothing but making the systems at home intelligent so as to make life easy without spending lot of money. This paper will help you understand what actually smart grid is, how it can be implemented and mainly focus upon the wireless communication in Smart Grid. The paper will present the architecture of Smart Grid using wireless connectivity and explain the importance of Home Area Networks. Security is the measure concern in case of wireless communication which is explained with some of the protocols to be used and Methods to avoid security threats. Wireless Technologies like Wi-Max, Wi-Fi, Zig-Bee and their use in the Smart Grid architecture is covered. Today, we are searching for a solution with less efforts and maintenance required and for the complicated electrical system, Smart Grid is the best solution to be implemented. Conventional Grid could not solve the problem of peak loads where users/consumers were unable to receive a proper service, it is complicated for the central system to manage large amount of load alone. Smart Grid solves this problem by distributing the management of energy and how it does, we will see in some of the chapters in this report. Smart devices like smart meters, Electric Vehicles can be used to make homes smarter. Smart Grid technology does not solve the problem of electricity only but also for water, gas etc. This technology is most suitable for smart city/village projects helping in making smarter devices and using communication between the devices, making human life more reliable and comfortable.

Visible-light-driven photoelectrochemical sensing platform based on BiOI nanoflowers/TiO2 nanotubes for detection of atrazine in environmental samples

In this work, a visible-light-driven photoelectrochemical (PEC) sensing platform was developed based on BiOI nanoflowers/TiO2 nanotubes (BiOI NFs/TiO2 NTs) for detection of atrazine (ATZ). The BiOI NFs/TiO2 NTs p–n heterojunctions synthesized by decorating BiOI NFs on TiO2 NTs via simple hydrothermal approach exhibit strong visible-light absorption ability, high photocurrent response and PEC activity. Thus BiOI NFs/TiO2 NTs heterostructures were first explored to act as the photoelectrode for the immobilization of the anti-ATZ aptamer to develop a PEC sensing platform. The design PEC aptasensing platform exhibits prominent analytical performance for determination of ATZ with a low detection limit of 0.5 pM under visible-light irradiation, and displays good selectivity for ATZ in the control experiments. The superior behavior of the sensing platform could be ascribed to the design of the appropriate sensing material with tubular microstructure, excellent PEC response of the photoelectrode, and the large loading amount of aptamer. Meanwhile, the PEC sensing platform was used to determine ATZ in environmental samples and a satisfied result was obtained.

Concrete Encased Steel Composite Columns: A Review

Concrete Encased Steel (CES) composite columns are those columns in which structural steel is encased inside reinforced concrete. By combining both materials, columns can handle a large amount of load with a lesser cross sectional area. Moreover they improves the overall rigidity of the building and provide significant resistance to lateral loads. These columns are widely used in high rise building construction. Main disadvantage of these columns are the construction difficulties. Since reinforcement bars and steel sections are encased, the concrete pouring becomes more difficult. Solution for these problems are the use of welding couplers or providing holes in steel flanges and steel web. Both the methods will increase the cost of construction and also it can affect the total bearing capacity and authenticity of the structure. An innovative method proposed to overcome these difficulties is the use of steel fibers and replacing the reinforcement bars. This paper discuss various studies conducted on concrete encased steel composite members.

Development and characterization of WPCs produced with high amount of wood residue

In this work, high levels of wood residue were incorporated into high density polyethylene (HDPE). The composite processing was carried out in a twin screw extruder. Due to the large amount of solid charge, adaptation of the equipment was necessary. Wood polymer composites (WPCs) with 60, 65 and 70% wood residue were obtained. In order to use composites in applications such as profiles for application on floors, an analysis of the fatigue strength of the composites was performed, as well as the water absorption capacity. The effect of ultra violet (UV) radiation on the surface of the composites was also evaluated using simulation in a degradation chamber. There was a significant increase in the stiffness of the composites and a reduction in flexural strength. Due to the large amount of load, formation of agglomerates was observed, which reduced the impact resistance. In spite of the use of compatibilizers, it was observed a weak adhesion between the phases, which impaired in the number of cycles under fatigue. When subjected to UV-degradation, the materials exhibited a small reduction in tensile strength. In general, the results indicate that the developed WPCs, considering applications in floors, presented some suitable properties such as rigidity and flexural strength, however, the processing conditions must be adequate for greater interaction between the phases.

Finite Element Method of Nickel Chromium and Nickel Vanadium for Alternative CNC Machine Tool

CNC tool is generally made of high speed steel (HSS) which has shorter life due to the increasing depth of cut. The steel shank wears within a short life time by the chips produced during machining process. And even the tool material cannot withstand a large amount of load. The damaged tool material is analysed and an alternate material is used to manufacture the tool. Alternate material used to manufacture the CNC tool which would have properties superior than HSS. The objective of this paper is to analyze the temperature increase & the thermal deformation of different materials like nickel-chromium and nickel-vanadium using Finite Element Analysis.

Generalized and feasible strategy to prepare ultra-porous, low density, compressible carbon nanoparticle sponges

For the last two decades, nanostructured carbon materials have attracted significant attention, as they exhibit unusual physicochemical properties different from their bulk counterpart. Nevertheless, agglomeration and re-stacking of carbon nanostructures have always limited optimal performance, with larger loading amount. To solve this issue, porous and compressible carbon-based sponges have been researched, but most of the previously suggested carbon foams were either not very porous, synthesized at high temperature heat treatment, and/or not applicable for carbon nanoparticles. In this work, we have successfully fabricated ultra-porous (porosity about 98–99%), polyimide-carbon nanoparticle (PI–C) composites by combining Ketjen black nanoparticles with PI short fibers, by simple freeze-drying and subsequent heat treatments at low temperature (240 °C). Based on the analysis, it has been discovered that the fabricated PI-C sponges not only exhibit highly robust mechanical properties but also retain low thermal conductivity even in comparison with pristine PI sponges. This work provides a milestone in fabricating a number of C-electrospun polymeric sponges by freeze drying and subsequent heat treatments, which are expected to be utilized in various fields of research.

Lithiophilic 3D Nanoporous Nitrogen-Doped Graphene for Dendrite-Free and Ultrahigh-Rate Lithium-Metal Anodes.

The key bottlenecks hindering the practical implementations of lithium-metal anodes in high-energy-density rechargeable batteries are the uncontrolled dendrite growth and infinite volume changes during charging and discharging, which lead to short lifespan and catastrophic safety hazards. In principle, these problems can be mitigated or even solved by loading lithium into a high-surface-area, conductive, and lithiophilic porous scaffold. However, a suitable material that can synchronously host a large loading amount of lithium and endure a large current density has not been achieved. Here, a lithiophilic 3D nanoporous nitrogen-doped graphene as the sought-after scaffold material for lithium anodes is reported. The high surface area, large porosity, and high conductivity of the nanoporous graphene concede not only dendrite-free stripping/plating but also abundant open space accommodating volume fluctuations of lithium. This ingenious scaffold endows the lithium composite anode with a long-term cycling stability and ultrahigh rate capability, significantly improving the charge storage performance of high-energy-density rechargeable lithium batteries.

The Design of Operational Amplifier for Low Voltage and Low Current Sound Energy Harvesting System

The objective of this paper is to design a combination of an operational amplifier (op-amp) with a rectifier used in an alternate current (ac) to direct current (dc) power conversion. The op-amp was designed to specifically work at low voltage and low current for a sound energy harvesting system. The goal of the op-amp design with adjustable gain was to control output voltage based on the objectives of the experiment conducted. The op-amp was designed for minimum power dissipation performance, with the means of increasing the output current when receiving a large amount of load. The harvesting circuits which designed further improved the power output efficiency by shortening the fully charged time needed by a supercapacitor bank. It can fulfil the long-time power demands for low power device. Typically, a small amount of energy sources were converted to electricity and stored in the supercapacitor bank, which was built by 10 pieces of capacitors with 0.22 F each, arranged in parallel connection. The highest capacitance was chosen based on the characteristic that have the longest discharging time to support the applications of a supercapacitor bank. Testing results show that the op-amp can boost the low input ac voltage (∼3.89 V) to high output dc voltage (5.0 V) with output current of 30 mA and stored the electrical energy in a big supercapacitor bank having a total of 2.2 F, effectively. The measured results agree well with the calculated results.

Transition Metal Oxide-Based Conversion Reaction for High-Capacity Lithium-Ion Batteries

The increasing demand for high efficiency large-scale energy storage applications (e.g. electric vehicles) has led to an expansion in new developmental efforts for high energy-density lithium-ion batteries. However, commercial graphite anodes based on conventional intercalation reaction (involving insertion or extraction of Li ions into or from a layer-type crystal structure) have been faced with a low theoretical specific capacity which prevents them from being applied in advanced energy storages. Transition metal oxide-based conversion reaction (2yLi++ MxOy ↔ xM + yLi2O) could be a novel approach to resolve the aforementioned issues. Here, a facile method is used where layers of nickel oxide (NiO) were formed on 3D Ni substrate via thermal oxidation; subsequently, graphene layers were directly grown on the 3D NiO-Ni structure. Within this structure, porous 3D Ni substrate offers high surface area to form a large loading amount of NiO; also, graphene layers provide structural buffer against volume variations during cycling. Thus, enhanced electrochemical performance is achieved by extending the cycle life and by improving the areal capacity of LIB. The 3D graphene-NiO-Ni structure delivered around 28 mg cm-2 areal density and exhibited an areal capacity of 1.2 mAh cm-2 at 0.1 mA cm-2. The excellent properties and a novel design of the 3D graphene-NiO-Ni anode will contribute to the development of large-scale lithium ion batteris.

Amorphous Molybdenum Sulfide Deposited Graphene Liquid Crystalline Fiber for Hydrogen Evolution Reaction Catalysis

Amorphous Molybdenum Sulfide Deposited Graphene Liquid Crystalline Fiber for Hydrogen Evolution Reaction Catalysis