This paper presents energy-saving driving methods for freight trains. First, we discuss a driving strategy that conserves energy considering running resistance and motor efficiency. Secondary, we ...confirm energy consumption and maneuverability, conducting running tests on several energy-saving driving methods. We also establish an energy simulation method by reproducing running tests. Finally, we verify the proposed driving method for energy-saving conducting energy simulation. This paper proposes a driving method combining constant-speed operation and coasting, which is expected to reduce energy consumption in terms of running resistance and motor efficiency.
Dumbbell-shaped hybrid nanoparticles, consisting of gold and iron oxide (Au-Fe3O4 NPs), show promise for magnetic hyperthermia cancer therapy. However, conventional synthesis methods using toxic iron ...pentacarbonyl (Fe(CO)5) raise safety concerns. We propose a safer approach using triiron dodecacarbonyl (Fe3(CO)12) as a precursor. We synthesize these NPs by initially reducing gold (III) chloride trihydrate with a tert-butylamine-borane complex at room temperature, yielding Au NPs. These Au NPs are combined with a Fe3(CO)12 solution and heated to 300 °C for 1 hour, resulting in the desired dumbbell-shaped Au-Fe3O4 NPs. Characterization confirms their morphology, with average sizes of 5 nm for Au NPs and 15 nm for Fe3O4 NPs. Our systematic evaluation of hydrophilic-treated Au-Fe3O4 NPs (Ms=49.5 emu/g at 3T, 300K) demonstrates temperature increases beyond the therapeutic threshold of 45 °C (ΔT=8 °C) at higher field strengths (8.6–30.0 kA/m), highlighting their cancer treatment potential. Quantitative analysis reveals superb performance, with a specific absorption rate (SAR) of 60.0 W/g and intrinsic loss power (ILP) of 0.25 nHm2kg−1 at the maximum field strength. These findings emphasize the significant potential of our dumbbell-shaped Au–Fe3O4 NPs for magnetic hyperthermia.
In this study, we aim to develop gold-coated Fe3O4 nanoparticles (Fe3O4@Au NPs) as theranostic agents for magnetic hyperthermia and CT imaging applications. The Fe3O4 NPs were synthesized via thermal ...decomposition method, and the gold was then deposited onto the surface of Fe3O4 NPs by reducing gold acetate at 190 °C. The average sizes of Fe3O4 and Fe3O4@Au NPs were 5.2 nm and 6.1 nm, respectively, which are effectively removed by the kidneys. The magnetization of Fe3O4@Au NPs (9.7 emu/g-Fe3O4) at 300 K was much smaller than that of Fe3O4 NPs (52.4 emu/g-Fe3O4). The heating efficiency of Fe3O4@Au NPs in water was sufficient to treat the tumor at 43–45 °C, and their high CT value of 851 HU was obtained. The synthesized ultrasmall Fe3O4@Au NPs showed great promise as a potential theranostic agent for magnetic hyperthermia and CT imaging applications.
Iron nitrides (FexNy) have attracted considerable attention as candidates for rare-earth-free hard magnetic material, and recently, the synthesis methods for FexNy nanoparticles have been ...established. Further, its magnetic properties might be useful for magnetic hyperthermia. Therefore, to assess its utility, the synthesis of FexNy nanoparticles was attempted in this study, and their magnetic properties and heat generation were compared with magnetite nanoparticles (MNPs), which have long been studied as biomaterials. Fe16N2 nanoparticles were successfully synthesized by reducing and nitriding MNPs with a size on the order of a few dozen nanometers, and the sample showed higher estimate heat generation than the MNPs. It was suggested that Fe16N2 nanoparticles might be used as thermal seeds for magnetic hyperthermia with higher heating efficiency.
Magnetic nanoparticles are widely studied for their use in various therapeutic and diagnostic purposes. As biomaterials, their biocompatibility is as important as their magnetic properties. Iron ...nitride (FexNy) has excellent magnetic properties, and thus FexNy nanoparticles could be useful as potential biomaterials. However, the biocompatibility of FexNy nanoparticles is yet to be investigated. In this study, we assessed the biocompatibility of FexNy nanoparticles by evaluating their direct‐contact cytotoxicity compared with that of magnetite nanoparticles (MNPs). Rat fibroblasts were incubated with the nanoparticle samples dispersed in culture medium at concentrations of 10, 50, and 100 μg/ml. The DNA concentration measurement, MTT assay, and trypan blue exclusion test were conducted after days 1 and 3 of incubation. After day 1, the cell viability decreased, and cell death increased with increasing sample concentration when compared with the control. However, after day 3, there were no significant differences when compared with the control, irrespective of the sample concentrations. Further, there were no significant differences between the FexNy nanoparticles and MNPs at the same concentrations in all the cytotoxicity evaluation tests. Therefore, it is suggested that FexNy nanoparticles might be as cytocompatible as the conventional MNPs.
Single-phase $\alpha"$-Fe 16 N 2 nanoparticles have been synthesized with high reproducibility in gram amounts for the first time. The nanoparticles were obtained through the various kinds of ...successive procedure starting from the reduction of Fe-oxides, followed by nitriding in an atmosphere with very low moisture and oxygen contents of less than 1 ppm through the entire process. The single-phase $\alpha"$-Fe 16 N 2 nanoparticles exhibited saturation magnetization ($M_{\text{s}}$) of 234 emu/g at 5 K and a magnetocrystalline anisotropy constant ($K_{\text{u}}$) of $9.6\times 10^{6}$ erg/cm 3 . These magnetic properties of this $\alpha"$-Fe 16 N 2 nanoparticles suggest that a new path for a possible candidate of the rare-earth-free permanent magnet material with a high $M_{\text{s}}$.
Anisotropic magnetoresistance (AMR) effects in Cox(Mn0.44Ga0.56)100−x epitaxial thin films were investigated in the temperature range of 5-300 K by changing the current (I) direction to the crystal ...axis and the Co content (x). The AMR ratios were mostly positive for I // Co2MnGa100 and negative for I // Co2MnGa110 and showed peak values at x = 49.7 at% for both current directions. AMR ratios calculated from s-d scattering theory, including crystal field effects with density of states information from first-principles calculations, well reproduced experimental features.
Poly (methyl methacrylate) (PMMA) bone cement is widely used as a filler for repairing bone defects. To improve the effectiveness of the treatment for bone defects caused by metastatic bone tumours, ...we propose the formulation of PMMA cement containing titania (TiO2) and magnetite (Fe3O4) that offers high bone affinity, making the cement suitable for use in magnetic hyperthermia. The TiO2 and Fe3O4 contents of the PMMA cement varied from 20 to 45 mass%. The various cement samples were evaluated for their apatite-forming ability and heat-generation characteristics. The samples containing TiO2 in concentrations of 15 mass% or higher formed apatite on their surfaces within 14 days in a simulated body fluid. The heat-generation characteristics of the samples were evaluated by applying an alternating current (AC) magnetic field under the following conditions: |H| = 40 Oe and f = 600 kHz, or |H| = 100 Oe and f = 100 kHz. The surface temperatures of the samples containing 25 and 30 mass% Fe3O4 reached 42.3 and 44.8 °C, respectively, at |H| = 40 Oe and f = 600 kHz. During hyperthermia treatment, cancer cells die at temperatures higher than 42 °C, and the cement samples fabricated in this study could reach this temperature. However, since some degree of heat loss will occur in vivo, it is necessary to ensure that the temperature is higher than 42 °C by varying the AC magnetic field. Nevertheless, the fact that the samples containing Fe3O4 concentrations of 25 mass% or higher generated enough heat under the AC magnetic field makes them suitable for clinical use in hyperthermia. Thus, PMMA cement containing 15 mass% or more of TiO2 and 25 mass% or more of Fe3O4 should be investigated as a bioactive bone cement with a strong hyperthermia effect.
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We developed a new cranioplasty method that utilizes artificial bone made of ultra-high-molecular-weight polyethylene, with a wedge-shaped edge (UHMWPE Wing). This study shows the methods and data of ...case series and finite element analyses with the UHMWPE Wing. A circumferential wing was preoperatively designed for a custom-made artificial bone made of UHMWPE to achieve high fixed power and to minimize the usage of cranial implants. Here, we present 4 years of follow-up data and finite element analyses for patients treated with the UHMWPE Wing between February 2015 and February 2019. Eighteen consecutive patients underwent cranioplasty using our UHMWPE Wing design. There were no postoperative adverse events in 17 of the patients for at least 18 months. One case of hydrocephalus experienced screw loosening and graft uplift due to shunt malfunction. Placement of a ventriculo-peritoneal shunt immediately returned the artificial bone to normal position. Finite element analyses revealed that a model using the UHMWPE Wing had the highest withstand load and lowest deformation. This is the first report on the UHMWPE Wing method. This method may enable clinicians to minimize dead space and achieve high strength in cranioplasty.
The dependence of the degree of order and perpendicular magnetic anisotropy (Ku⊥) on magnetic layer thickness (dmag) for FePt granular films with various grain boundary materials (GBMs) were ...investigated. According to the analysis for granular films with a constant GBM volume of 30 vol%, the order, disorder, and non-epitaxial portions co-existed in the FePt granular films. From the separate quantitative evaluation for these portions, the following was found; 1) the degree of order and magnitudes of Ku⊥ for disorder and order portions against dmag were constant, while the film average evaluation resulted in the dependence of the degree of order and Ku⊥ on dmag and the positive correlation between the grain diameter and the degree of order, 2) for the order portion, Ku⊥ had linear correlation with the degree of order, 3) the magnitude of Ku⊥ and the degree of order for the order portion depended on GBM.
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