Modern Physics Letters B

Two types of biodegradable chitosan-base boron adsorbents were synthesized by introducing D-glucamine and N-methyl-D-glucamine functional groups. Structural analysis was carried out using ¹H-NMR. The maximum boron adsorption values were 3.5 mg g${}^{-1}$ (equilibrium concentration, $C_e=192$ ppm), and 7.3 mg g${}^{-1}$ ($C_e=173$ ppm) for D-glucamine and N-methyl-D-glucamine type chitosan adsorbents, respectively. The obtained boron adsorption capacity of N-methyl-D-glucamine modified chitosan was found to be 7.3 mg g${}^{-1}$ ($C_e=173$ ppm) higher than that of the boron absorbent Amberlite IRA743. Thus, the biodegradable $N$-methyl-D-glucamine-modified chitosan synthesized in this study is expected to be useful as a commercial product.

The laser ablation in liquid is a simple, easy, and less hazardous method available to create nanoparticles without chemical additives. In this paper, nanosecond laser ablation was conducted in various aqueous solvents to create tin oxide (SnO${}_2)$ nanoparticles from bulk SnO powder. After the laser ablation at 532 nm wavelength, the prepared samples were examined by UV–visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). UV–visible spectra showed that the significantly different absorption characteristics of nanoparticles are dependent on the original SnO amount in the solvent. The SEM observation clearly showed the creation of SnO₂ nanoparticles of about 10–20 nm in size with irregular shapes, which were found to be secondary nanoparticles from the TEM images. Interestingly, a three-dimensional octahedral structure with a size of 220–300 nm having the surface made of aggregates of fine nanoparticles was confirmed by TEM analysis. From the EDS spectra, it was clarified that the octahedral agglomeration is made from tin and oxygen, and the electron diffraction image confirmed the formation of the SnO₂ crystalline phase.

The micro/nano blocks of Ni/MnO composites were synthesized by a facile microwave-assisted solvothermal method. The results indicated that the morphology changed from irregular block to polyhedron and then to the sphere with the increase of ethylene glycol (EG) ratio in the solvent. The results indicated the specific capacitance of the obtained material increased as the EG ratio increased, but when the EG ratio exceeded 60%, the change of specific capacitance was not obvious (less than 5%). For the Ni/MnO material synthesized in pure EG, its specific capacitance reached 860 F/g at 1 A/g and the capacitance retention maintained 58% after 6500 cycles. The micro/nano structure of Ni/MnO material formed in EG solvent increased the surface area and provided more transfer channels for the electrolyte ion, which were all beneficial to improve the electrochemical properties. The high capacitance and good cycle stability especially after a period of cycles demonstrated the obtained Ni/MnO materials had a potential application for the supercapacitor electrode material.

Wire-directed energy deposition (wire-DED) is used to create a shape in a layer-by-layer manner by depositing a consumable welding wire, where a welding arc is the source of heat. This technology can be used to fabricate large components with higher deposition rates compared to other 3D metal printing methods. Despite these benefits, the components of wire-DED are affected by heat distortion and residual stress. Therefore, the prediction of deformation before fabrication using wire-DED is essential for determining the range of machining for the final products. In this study, the deformation and time required were evaluated using various simulation models of wire-DED.

Despite the satisfactory development in preparing heteroatom-doped porous carbon/Sn composite structures, most strategies rely on complicated and multi-step template processes to tailor the porous carbon structure. Herein, a facile, economical, and environmental-friendly strategy for the one-step synthesis of N, P co-doped porous C/Sn (Sn/NPPC) composite is reported. The NPPC can relieve the large volume change and supply good electronic conductivity as well as more defects. Benefiting from the integration of these advantages, the Sn/NPPC electrode achieves superior discharge capacity (689.5 mAh/g after 100 cycles at 100 mA/g). This strategy can supply fundamental breakthroughs for reducing the synthesis cost and simplifying the synthesis complexity of heteroatom-doped porous carbon/Sn composite.

Absorbed Glass Mat (AGM) waste filaments are waste staple fibers from the production of AGM functional paper. Incorporation of AGM waste filaments into solid waste based curing agents, the experimental results showed that the maximum increase in compressive strength and flexural strength of the cured specimens was achieved when 5% mass fraction AGM waste filament was added with compressive strengths of 9.87 MPa and 10.96 MPa at 7 d and 28 d, respectively, representing an increase of 15.57% and 17.34% compared to the unadulterated one. The flexural strength was increased by 53.55% and 49.71% compared with that of the unadulterated AGM waste filament. The strength enhancement effect of mixing different shapes of AGM waste filaments is higher than that of mixing each shape alone, which proves that AGM waste filaments have a mixed enhancement effect.

A boron-doped diamond (BDD) thin film was synthesized using the hot filament chemical vapor deposition (HFCVD) method. The surface shape, growth rate, bonding structure, and electrochemical properties of the BDD thin films were estimated through scanning electron microscopy (SEM), Raman spectroscopy, and cyclic voltammetry. As the boron doping concentration increased, the growth rate and crystal size of the diamond thin film decreased. Through Raman analysis, it was confirmed that the 1332 cm${}^{-1}$ peak of diamond gradually became less intense, and peaks were generated at 480 cm${}^{-1}$ and 1220 cm${}^{-1}$ due to the bonding of boron to carbon. Cyclic voltammetry analysis of the BDD thin film showed a large potential window with a width of approximately 2.8 V. The highest applied voltage (2 V) versus response current (0.02 A) was obtained at a B/C ratio of 2000 ppm.

Single-crystal precursor of hybrid oxides NiO–MnCo₂O₄–Ni₆MnO₈ (SCNCM) is synthesized via an improved continuous two-step spray pyrolysis system (CTSP). This kind of mixed oxide is to be regarded as an ideal precursor for the single-crystal Ni-rich Li[Ni${}_{0.6}$Co${}_{0.2}$Mn${}_{0.2}$]O₂ cathode materials (SCLNCM). The new pilot plant (30 t/a), method, and chlorate in this work could extremely improve the lengthy process, reducing segregation of metal element, excessive sintering temperature, high water consumption, non-polluting, and production efficiency of the SCLNCM. The resulting SCLNCM powders have a type of fine particle size and porous structure with a typical $\alpha$-NaFeO₂ lamellar structure. It also has a type of better cyclic stability, safety, rate capability, crystallinity, and surface area than polycrystalline cathode materials. It delivers an initial discharge capacity of 184 mAh/g at 0.1 C (18 mA/g) with a capacity retention of 91% after 100 cycles in the voltage window of 2.8–4.3 V.

In this study, a sandwich-structured electrode composed of indium tin oxide (ITO)/metal silver layer/ITO was prepared by the radio frequency magnetron sputtering method. We used the Taguchi method and spectroscopic ellipsometry (SE) analysis to optimize the geometrical structures of the electrodes and the sputtering power for the silver layer. While the Taguchi method allows us to rapidly optimize the manufacturing parameters, SE analysis enables us to precisely evaluate the thickness of each layer of the electrodes, so that the whole optimization process is more precise and effective. When the silver layers of different samples are sputtered under the same conditions, the difference in their thickness is often $>1$ nm. Thus, it is difficult to understand the influences of the manufacturing parameters on the optoelectronic performance of the electrodes. Experimental results show that the thickness of the silver layer was the main factor affecting the transmittance and sheet resistance of the electrodes. However, the decisive factors for the Haacke index in the visible light range were the thickness of the bottom ITO film. Nonetheless, the signal-to-noise (S/N) ratios of some factors are quite close. Thus, further analyses are needed to understand this phenomenon. After optimization, the Haacke index is $20.17\times 10^{-3}{\mathrm{\Omega }}^{-1}$, which is better than the 19.45 of the best sample, suggesting that this experiment has improved the optoelectronic properties of the electrode.

Bearings, which are widely used in the industry, require high-energy efficiency and durability, and research toward frictional wear improvement is in progress. In this study, micropatterns were fabricated on the surface of an STB2 bearing steel. Three types of line-shaped micropatterns with intervals of 40, 80, and 150 μm were processed using a milling machine. In addition, the friction efficiency was assessed by measuring the friction coefficient of a bare sample with a diamond-like carbon (DLC) thin film, which has excellent friction efficiency. The friction wear efficiency was further analyzed by comparing the change in friction coefficient and the wear area as a function of the pattern interval. As a result of the wear test, the STB2 specimen to which the pattern was applied showed a difference in the friction coefficient according to the pattern pitch, and the lowest coefficient of friction was shown at 40 μm with the smallest pattern pitch, which confirmed that the distance between the pattern pitches affected the friction characteristics.

The removal of phosphate (PO${}_4^{3-})$ from an aqueous solution by clamshell treated by heat process was investigated through batch experiments. The effects of initial phosphate concentrations, pH value, and contact time on the phosphate removal were carried out. The phosphate adsorption isotherm was described by the Langmuir and Freundlich models. As the result, the adsorption process correlated well to both models, and the theoretical maximum phosphate adsorption capacity was 319.0 mg/g by the Langmuir isotherm model. The influence of pH was investigated from 5 to 10, and the value of pH had no significant effect on phosphate adsorption capacity. This finding indicated the application of calcined clamshell in the large range of pH for phosphate removal. The phosphate adsorption capacity and phosphate removal efficiency were obtained at 209.0 mg/g and 38.7% at the initial phosphate concentration of 540 ppm at 25^∘C for 24 h, respectively. The clamshell modified by heat treatment exhibited its substantial potential for fast and efficient phosphate removal in water and wastewater.

A basic study was conducted to investigate the correlation between assist gas pressure and the amount of secondary waste generated during underwater laser cutting for nuclear decommissioning. The assist gas pressure, i.e. the main parameter, was changed from 2 to 15 bar. Cutting quality was evaluated based on the shape of the cutting cross-section and the roughness of the cutting surface. In addition, the weight loss closely related to the generated secondary waste was calculated, and the schlieren method was used to check the gas flow according to the assist gas pressure. Satisfactory cutting quality could be obtained at a minimum assist gas pressure of 10 bar, and the weight loss related to secondary waste was less. When the cutting quality was good, the weight loss was less, and secondary waste generated was minimum.

In this study, an amorphous carbon thin film on a cemented carbide substrate was prepared with surface micropatterns using femtosecond laser machining. The micropatterns that were considered were made of lines, dotted lines, and zigzag dotted lines. We performed a tribology test using a ball-on-disk friction wear test and investigated the coefficient of friction (COF) and wear amount as a function of pattern size and shape. The micropattern made using femtosecond laser patterning exhibited better friction coefficient properties than the bare amorphous carbon samples. Moreover, the pattern size and shape influenced the friction coefficient value of the patterned samples. The dotted line pattern shape showed superior results in friction coefficient characteristics compared to those of other micropatterns.

With cement as a cementitious material, fly ash, diatomaceous earth, sugar filter mud, and river sand as materials, and waste leachate instead of water, orthogonal experiments were designed to derive the preliminary formulation of curing materials and to explore the effect of different diatomaceous earth mixing amount on the performance of curing material test blocks. The experimental results showed that as the amount of diatomaceous earth increased from 12.5% to 13.58%, the 28d compressive strength of the cured material test block decreased from 9.85 MPa to 7.35 MPa, the dry density decreased from 1012 kg/m³ to 912 kg/m³, the porosity of the test block increased from 18.94% to 23.34% and the water absorption increased from 43.91% to 66.36%. Comparison of the best formulation of curing materials selected for cement, fly ash, diatomaceous earth and sugar filter mud mass ratio of 31.09 wt.%, 51.82 wt.%, 12.94 wt.%, 4.15 wt.%, external mixing river sand 15 wt.%, with a water–solid ratio of 0.8 was added to the waste leachate to prepare the curing material test blocks.