Narrow Results

Joint arthroplasty, specifically total knee arthroplasty (TKA) and total hip arthroplasty (THA), are two of the highest value surgical procedures. Over the last several decades, the materials utilized in these surgeries have improved and increased device longevity. However, with an increased incidence of TKA and THA surgeries in younger patients, it is crucial to make these materials more durable. The addition of nanoparticles is one technology that is being explored for this purpose. This review focuses on the addition of nanoparticles to the various parts of arthroplasty surgery comprising of the metallic, ceramic, or polyethylene components along with the bone cement used for fixation. Carbon additives proved to be the most widely studied, and could potentially reduce stress shielding, improve wear, and enhance the biocompatibility of arthroplasty implants.

This paper highlights the reinforcement of two different fibers in the manufacturing of hybrid laminate composites. The feasibility of glass and carbon fiber-based hybrid composites is proposed for various high performances due to their versatile mechanical properties. However, anisotropic and non-homogeneity nature creates several machining challenges for manufacturers. It can be regulated through the selection of proper cutting conditions during the machining test. The effect of process constraints like spindle speed (rpm), feed rate (mm/min), and stacking sequences ($C)$ was evaluated for the optimum value of thrust force and Torque during the drilling test. The cost-effective method of hand layup has been used to fabricate the composites. Four different hybrid composites were developed using different layers of carbon fiber and glass fiber layers. The outcomes of variables on machining performances were analyzed by variation of feed rate and speed to acquire the precise holes in the different configurations. The application potential of the proposed composites is evaluated through the machining (drilling) efficiency. The optimal condition for the drilling procedure was investigated using the multiobjective optimization-Grey relation analysis (MOO-GRA) approach. The findings of the confirmatory test show the feasibility of the MOO-GRA module in a machining environment for online and offline quality control.

Multi-element doped porous carbon materials are considered as one of the most promising electrode materials for supercapacitors due to their large specific surface area, abundant mesoporous structure, heteroatom doping and good conductivity. Herein, we propose a very simple and effective strategy to prepare nitrogen, sulfur co-doped hierarchical porous carbons (N-S-HPC) by one-step pyrolysis strategy. The effect of sole dopants as a precursor was a major factor in the transformation process. The optimized N-S-HPC-2 possesses a typical hierarchically porous framework (micropores, mesopores and macropores) with a large specific surface area (1284.87m² g${}^{-1})$ and N (4.63 atomic %), S (0.53 atomic %) doping. As a result, the N-S-HPC-2 exhibits excellent charge storage capacity with a high gravimetric capacitance of 360F g${}^{-1}$ (1 A g${}^{-1})$ in three-electrode systems and 178F g${}^{-1}$ in two-electrode system and long-term cycling life with 87% retention after 10,000 cycles in KOH electrolyte.

The South Korean government aims to achieve carbon neutrality by 2050. Here, this study analyzed the economic efforts of the net-zero policy by integrating top-down and bottom-up models; The UNIfied Climate Options Nexus (UNICON) within this study aims to create a link between the 26 sectors from the bottom-up model and the 85 sectors of the top-down model. Positive mathematical programming methods were used to ensure consistency between the top-down and bottom-up models within the base year. The study found that the total reduction rate was slightly higher in the integrated model than in the computable general equilibrium (CGE) stand-alone model. In both models, the reduction rate increased when the carbon tax increased, but the marginal reduction rate was considerably lowered, and the reduction rate did not exceed 80% even with the high level of a carbon tax. The technological change of the linked industries in the integrated model showed that the steel industry had the highest emission reduction. When estimating costs for reducing GHGs, results can vary based on the technological changes under consideration.

In rechargeable lithium-sulfur (Li-S) batteries, the conductive carbon materials with high surface areas can greatly enhance the electrical conductivity of sulfur cathode, and metal oxides can restrain the dissolution of lithium polysulfides within the electrolyte through strong chemical bindings. The rational design of carbon-metal oxide nanocomposite cathodes has been considered as an effective solution to increase the sulfur utilization and improve cycling performance of Li-S batteries. Here, we summarize the recent progresses in the carbon-metal oxide composites for Li-S battery cathodes. Some insights are also offered on the future directions of carbon-metal oxide hybrid cathodes for high performance Li-S batteries.

This paper describes and analyzes a proposal for a pay-for-cuts carbon treaty and illustrates how it would work with numerical simulations for 186 countries. A treaty board would pay each country’s government an amount P for each CO₂ ton the country cuts by any method. Each government would decide how to get its firms and households to cut CO₂ emissions; the board would encourage a carbon tax or cap-and-trade but not require it. $R_i$ is the number of tons that country i reduces its CO₂ emissions. $R_i$ equals country i’s base emissions minus its actual emissions which are publicly available data. Country i’s government would receive $P{R}_i$ from the board. The board’s $P{R}_i$ payments would be financed by country government contributions to the board. A formula would give each country’s government the amount it must contribute each year. The formula would aim to make government contributions equal to the board’s $P{R}_i$ payments and equitably distribute the burdens from cutting world emissions. Representatives of the countries would have to approve the board’s most important decisions.

The carbon is an important element which belongs to group 14 of the periodic table and shows multiple applications in our daily life as well as at the industrial scale. It is a promising element which represents the liquid–liquid phase transition (LLPT) phenomena. Additionally, it shows interesting anomalous behavior with some usual thermodynamic properties such as heat capacity ($C_p$) near about the liquid–liquid phase coexistence temperature ($T_c$). Hence, it is quite challenging and difficult to simulate carbon at or near the liquid–liquid phase coexistence temperature. This anomalous behavior also creates complications in computing the precise and equilibrated thermodynamic properties close to $T_c$. Therefore, we have studied the thermodynamic behavior of liquid and solid (diamond) states of carbon at liquid–liquid phase coexistence temperature ($T_c$) while transforming from liquid to solid state and achieving the equilibrated liquid and solid states individually. Additionally, we have also performed a similar analysis on melting temperature ($T_m$) to compare the system trends and its thermodynamics behavior in liquid and solid states, respectively. Furthermore, all the predicted thermodynamic results are quite consistent and able to show the equilibrium changes at the liquid–liquid phase coexistence temperature ($T_c$) and melting temperature ($T_m$), respectively.

The structural and mechanical properties of 9R diamond and 12R diamond have been investigated by using the first-principles calculations. The elastic constants, bulk modulus and Young’s modulus at various pressures have been investigated. The elastic anisotropy under pressure from 0 to 100 GPa has been studied. From our calculations, we found that 9R diamond and 12R diamond have similar high elastic constants and elastic modulus as lonsdaleite and diamond. The detailed ideal strength calculations show that 9R diamond and 12R diamond are intrinsic superhard materials.

Nanofluids are promising in solar harvesting and solar thermal utilization. Ethylene glycol (EG) nanofluids have the advantages of high boiling point and low volatility, and therefore are highly desired in some circumstances. In this study, the solar harvesting and solar thermal conversion properties of EG were significantly enhanced by carbon chain nanostructures (CCNSs). The prepared CCNSs/EG nanofluids showed greater optical absorption compared to EG in the wavelength range from 250nm to 1400nm. The solar weighted absorption factor (Am) of the CCNSs/EG nanofluids was 95.9% at the mass fraction of 0.05 wt.%. The enhancement was 649.2% compared to that of EG. The photothermal conversion efficiency was determined to be 97.7% and the enhancement of 83.0% was achieved. An enhancement of 1.2% in thermal conductivity was also been observed. These enhancements can be ascribed to the special architectures of the CCNSs that provide fast transfer path for the generated heat.

As green anode materials with wide distribution, controllable cost, and diversified structure, carbon materials have received more attention. In this paper, iodine- and nitrogen-co-doped carbon flower materials were prepared. The flower-like structure of the material ensures the rapid diffusion of lithium ions, and the synergistic effect of iodine and nitrogen atoms improves the pore size distribution, the conductivity and the active sites of carbon materials realizing the high ion storage and the fast charge diffusion. As the anode material of lithium-ion batteries, the iodine- and nitrogen-co-doped carbon flower could have the capacitance of 410 mAh g${}^{-1}$ at the current density of 0.1 A g${}^{-1}$ after 150 cycles and 181 mAh g${}^{-1}$ at the high current density of 2.0 A g${}^{-1}$ after 1000 cycles. The results of electrochemical impedance spectroscopy, kinetics, and GITT show this material has fast charge transport kinetics and excellent rate performance.

In this paper, carbon particles with micro- and nano-particle size were synthesized through a hydrothermal reaction of glucose, namely C-1(123.1 nm), C-2(229.2 nm), C-3(335.1 nm), C-4(456.2 nm) and C-5(534.0 nm) with distinct sizes. We utilized five size carbon particles as individual fillers into the EHS matrix materials to prepare composite eutectic phase change materials (C/EHS PCMs) by melt blending technique. The impact of carbon particle size on the dispersion stability and thermal properties of Na₂SO₄⋅10H₂O–Na₂HPO₄⋅12H₂O (EHS) phase change materials was investigated. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) analysis were done to analyze the diameters of carbon particles. The cryogenic-scanning electron microscopy (Cryo-SEM) analysis indicated that the carbon particles resulted in modification in the morphology of the EHS. The results of in situ X-ray diffraction (XRD) and Fourier-transformed infrared (FTIR) analysis showed only simple physical mixing between carbon particles and EHS. It is shown that adding 0.2 wt.% C-2 can decrease the supercooling degree of EHS to 1.5${}^{\circ }$C. The cyclic stability of C/EHS varies significantly depending on the size of carbon particles. The thermal conductivity of EHS increased by 42.1%, 39.9%, 14.4%, 19.5%, and 18.8% with the addition of C-1, C-2, C-3, C-4, and C-5, respectively, at a mass fraction of 0.2%. The results of differential scanning calorimetry reveal that the incorporation of C-1, C-2, C-3, and C-4 into EHS leads to an enhancement of latent heat. The latent heat capacity of EHS with 0.2 wt.% C-2 is 243.4 J⋅g${}^{-1}$, and after undergoing 500 cycles of solid-liquid phase transition, the latent heat remained above 200 J⋅g${}^{-1}$. Through the comprehensive analysis, the C-2/EHS composite phase change material holds significant potential for advancing building insulation and solar energy storage technologies.

The solution plasma process (SPP) has attracted considerable attention for the synthesis of carbon nanomaterials; the SPP uses electrical discharges generated directly by a bipolar pulsed power supply for various combinations of the solvents and solutes in the solution. However, the SPP requires high-temperature heat treatment for enhancing conductivity and exhibiting catalyst activity. Furthermore, the metal used as the electrode in the SPP is generally sputtered during discharge. This study presents the feasibility of reducing the heat-treatment step and solving the problem of sputtering of the metal electrodes by simply increasing the repetition frequency of the bipolar pulsed power. During synthesis, the pulse frequency acts as the graphitization catalyst. The enhancement of crystallinity was further confirmed by X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The findings of this study are expected to contribute toward research on improving the properties of carbon for various applications of the SPP synthesis methods.

This study examines the machinability of hybrid fiber metal laminates (HFML), which are made by nickel–chromium alloy (IN-625) metal-cored carbon (Ca)/aramid (Ar) fiber laminate using ultrasonic vibration-coupled microwire electrical discharge machining (UV-$\mu$WEDM). Since UV-$\mu$WEDM parameters significantly impact the erosion rate ($E_R$) and surface undulation ($S_U$), the main objective was to identify the optimal machining parameters. The input variables include the pulse on ($P_{\text{on}}$), pulse off ($P_{\text{off}}$), current ($I_C$), cutting inclination ($C_I$), and servo voltage ($S_V$) coupled with ultrasonic vibration (UV). The empirical findings show that the servo voltage ($S_V$) significantly impacts $E_R$ (73.93%) and $S_U$ (70.02%). The performance categorization order of significant influencing variable is $S_V>P_{\text{off}}>C_I>P_{\text{on}}>I_C$. The desirability interpretation generated the optimum setting for minimizing $S_U$ and maximizing $E_R$ is $P_{\text{on}}=8\mu$s, $P_{\text{off}}=14\mu$s, $S_V=50$V, $I_C=3$A, and $C_I=30^{\circ }$. Scanning electron microscopic (SEM) images were used to perform the micro-interlayer analysis on the machined surface. Moreover, creating an appropriate HFML is necessary to cut various shapes and sizes to satisfy the demands of diverse applications. 60% of components in the aerospace sector are reportedly rejected in real time due to dimension departure, poor surface finish, and damage found in the final assembly. Investigating the viability of cutting-edge machining techniques like UV-$\mu$WEDM is crucial to minimize damage and improve the quality of HFMLs.

Carbon quantum dots (C QDs) were synthesized using lemon juices as a precursor by hydrothermal method. The impact of C QDs on the biomass, density of spores, and morphology of Aspergillus oryzae (A. oryzae) was studied for the first time. The results revealed that C QDs had a graphite structure, and their average size was about 4.25nm. As a carbon source, C QDs were more beneficial to A. oryzae growth than glucose. It has been observed that C QDs worked as an activator to improve the yield of A. oryzae, and the biomass and density of spores of A. oryzae cultured with 15mg C QDs were about 1.46 and 2.00 times higher than that in control medium (without C QDs). Our work can give a new idea for improving the yield of A. oryzae or microorganisms and satisfy industrial requirements.

The increasing energy crisis promotes the study on novel electrode materials with high performance for supercapacitive storage and energy conversion. Transition metal phosphates have been reported as a potential candidate due to the unique coordination and corresponding electronic structure. Herein, we adopted a facile method for preparing NaCoPO₄@C derived from a metal organic framework (MOF) as a bifunctional electrode. ZIF-67 was synthesized before a refluxing process with Na₂HPO₄ to form a precursor, which is transformed into the final product via calcination in different atmospheres. Specifically, the resultant NaCoPO₄@C exhibits a high specific capacitance of 1178.7Fg${}^{-1}$ at a current density of 1Ag${}^{-1}$ for a supercapacitor. An asymmetric supercapacitor (ASC) assembled with active carbon displays a high capacitance of 163.7Fg${}^{-1}$ at 1Ag${}^{-1}$. In addition, as an oxygen evolution reaction (OER) catalyst, the NaCoPO₄@C electrode requires only 299mV to drive a current density of 10mAcm${}^{-2}$. These results suggest that the rational design of MOF-derived NaCoPO₄@C provides a variety of practical applications in electrochemical energy conversion and storage.

Recent research has shown that fly ash may catalyze the oxidation of elemental mercury and facilitate its removal. However, the nature of mercury-fly ash interaction is still unknown, and the mechanism of mercury retention in fly ash needs to be investigated more thoroughly. In this work, a fly ash from a coal-fired power plant is used to characterize the inorganic and organic constituents and then evaluate its mercury retention capacities. The as-received fly ash sample is mechanically sieved to obtain five size fractions. Their characteristics are examined by loss on ignition (LOI), scanning electron microscope (SEM), energy dispersive X-ray detector (EDX), X-ray diffraction (XRD), and Raman spectra. The results show that the unburned carbon (UBC) content and UBC structural ordering decrease with a decreasing particle size for the five ashes. The morphologies of different size fractions of as-received fly ash change from the glass microspheres to irregular shapes as the particle size increases, but there is no correlation between particle size and mineralogical compositions in each size fraction. The adsorption experimental studies show that the mercury-retention capacity of fly ash depends on the particle size, UBC, and the type of inorganic constituents. Mercury retention of the types of sp² carbon is similar to that of sp³ carbon.

In rechargeable lithium-sulfur (Li-S) batteries, the conductive carbon materials with high surface areas can greatly enhance the electrical conductivity of sulfur cathode, and metal oxides can restrain the dissolution of lithium polysulfides within the electrolyte through strong chemical bindings. The rational design of carbon-metal oxide nanocomposite cathodes has been considered as an effective solution to increase the sulfur utilization and improve cycling performance of Li-S batteries. Here, we summarize the recent progresses in the carbon-metal oxide composites for Li-S battery cathodes. Some insights are also offered on the future directions of carbon-metal oxide hybrid cathodes for high performance Li-S batteries.

Crystalline cubic silicon carbide (3C-SiC) surface layers have been prepared by carbon-ion implantation into silicon (100) using a MEVVA ion source and subsequent annealing at 1250°C for 2 h. The obtained films have been characterized by SEM, XRD, and micro-Raman analysis. The effect of carbon-ion dose on the surface morphology of the ion-implanted samples has been investigated. Rectangular patterns are observed on the surfaces of carbon-ion-implanted silicon substrates. It is found that the amount of rectangular patterns increases with ion dose, suggesting the dependence of surface morphology on ion dose. The formation of rectangular patterns has been elucidated in this paper.

This chapter describes how economic models are used to answer questions about policy changes, specifically in the context of a carbon fee-and-dividend system. A carbon fee-and-dividend is a price on carbon dioxide emissions that returns the revenues gained to ordinary households in the form of a monthly check. The chapter describes, in nontechnical terms, the economic models and modeling processes involved and how they are similar and different from climate models…

A systematic investigation of structural, mechanical, elastic anisotropy and electronic properties of a recently reported novel superhard material orthorhombic $C_{20}$ ($o$-$C_{20}$) under pressure is performed utilizing the density functional theory in this work. The crystal structure parameters are obtained at zero as well as at high pressure. Pressure induced elastic constants $C_{ij}$, polycrystalline aggregate elastic modulus $(B,G,E)$, $B/G$ ratio, and Debye temperature changes for $o$-$C_{20}$ have been determined. The crystal elastic anisotropies of the ultra-incompressible $o$-$C_{20}$ are investigated in the pressure range of 0–100 GPa. The Lyakhov–Oganov model is applied to predict the hardness as functions of pressure. The calculated results reveal that $o$-$C_{20}$ possesses high elastic anisotropy under zero pressure and high pressure, and the hardness of $o$-$C_{20}$ decreases with pressure, while the Debye temperature behaves with the opposite trend. The results of electronic structure indicate that $o$-$C_{20}$ exhibits insulator characteristics, and the band gap increases with pressure. This work is expected to provide a useful guide for the future synthesis and application of $o$-$C_{20}$.