Lithium-ion batteries have been considered a suitable battery technology for energy storage systems. However, its scarcity and high cost pose challenges to the availability of lithium for mass adoption in large applications such as energy storage. Due to their natural abundance and economic feasibility, sodium-ion batteries (SIBs) have proven to be a promising alternative for large-scale applications.1 Most anode materials for research on SIBs have focused on carbonaceous materials, oxides and polyanionic compounds of the anode, like that of lithium-ion battery research on anode materials Polyanionic compounds, especially phosphates, are of particular interest due to their structural, thermal properties and, more importantly, for avoiding undesirable sodium plating.2 Contrary to lithium counterparts, SIBs have fewer alternatives for safe anode materials applicable for both non-aqueous and aqueous rechargeable SIBs.3 Various NaTiOPO4 polymorphs have previously been reported, and these materials required a synthesis process that was extremely time-consuming and a highly pressured synthesis atmosphere. However, the methods reported still produced very small amounts of synthesized material.4-8 Due to these limitations, only the β-NaTiOPO4 phase among polymorphs was studied as an anode for SIBs in a non-aqueous electrolyte.7-8 In this study, we first report a simple and scalable solid-state synthesis method for γ-NaTiOPO4, which incorporates a high-temperature quenching process to stabilize metastable γ-NaTiOPO4 with stability. It is a promising anode for SIBs in non-aqueous and aqueous electrolytes, with a capacity of roughly 120mAh/g, voltages of 1.7V and 1.5V vs Na/Na +, and a Coulombic efficiency of up to 99.9% for up to 500 cycles at 0.5C in non-aqueous electrolyte and excellent capacity retention in a full cell of NaMn0.44O2//γ-NaTiOPO4 for up to 175 cycles in aqueous electrolyte.9 El Kharbachi, A.; Zavorotynska, O.; Latroche, M.; Cuevas, F.; Yartys, V.; Fichtner, M., Exploits, advances and challenges benefiting beyond Li-ion battery technologies. Journal of Alloys and Compounds 2020, 817.N. Yabuuchi, K. Kubota, M. Dahbi, S. Komaba, Research development on sodium-ion batteries, Chem. Rev. 114 (23) (2014) 11636–11682. H. Kim, J. Hong, K.Y. Park, H. Kim, S.W. Kim, K. Kang, Aqueous rechargeable Li and Na ion batteries, Chem. Rev. 114 (23) (2014) 11788–11827. Stus, N. V.; Slobodyanik, M. S.; Straitiychuk, D. A.; Lisnyak, V. V., Pressure induced gamma ->alpha-NaTiOPO4 phase transition. J Alloy Compd 2005, 393 (1-2), 66-69.Dahaoui, S.; Hansen, N. K.; Protas, J.; Krane, H.-G.; Fischer, K.; Marnier, G., Electric properties of KTiOPO4 and NaTiOPO4 from temperature-dependent X-ray diffraction. Journal of Applied Crystallography 1999, 32 (1), 1-10.Loiacono, G. M.; Loiacono, D. N.; Stolzenberger, R. A., Growth and properties of crystals in the system KTiOPO4-NaTiOPO4. Journal of Crystal Growth 1994, 144 (3), 223-228.Mu, L. Q.; Ben, L. B.; Hu, Y. S.; Li, H.; Chen, L. Q.; Huang, X. J., Novel 1.5 V anode materials, ATiOPO(4) (A = NH4, K, Na), for room -temperature sodium-ion batteries. Journal Jiang, L. W.; Liu, L. L.; Yue, J. M.; Zhang, Q. Q.; Zhou, A. X.; Borodin, O.; Suo, L. M.; Li, H.; Chen, L. Q.; Xu, K.; Hu, Y. S., High-Voltage Aqueous Na-Ion Battery Enabled by Inert-Cation-Assisted Water-in-Salt Electrolyte. Advanced Materials 2020, 32 (2).Kim, D.; Park, H.; Avdeev, M. ; Kim, M. ; Kang, B. (2022). Newly developed γ – NaTiOPO4 by Simple Solid-State Synthesis for Anode Material of Na-ion Batteries in Both Non-aqueous and Aqueous electrolyte. Journal of Power Sources 2022, 541 (1)

Thin Wall Structures (TWS) have applications in many fields of physics and engineering. Laser-Based Powder Bed Fusion (LB-PBF) is a free-form fabrication that can easily produce the TWS in a single production step. However, due to the thin nature of this component and the interaction of thermal forces on the lateral surface, the chance of defects such as cracks and distortion is high. Therefore, this research aims to investigate the effect of power, inclination angle and the number of laser passes upon dimensional (thickness) deviation, distortion and porosity of TWS made by LB-PBF. Investigating the mentioned parameters is useful to determine the capability of LB-PBF to produce Al–Si–10Mg​ TWS as well as manufacturability of these structures. To identify the effect of inclination angle, number of laser passes and laser power on dimensional deviation, distortion and porosity a full factorial Design of Experiments (DOE) has been selected. To discuss the results statistical analyses and simulation of LB-PBF are implemented. Simulations have been carried out using computational fluid dynamic software (Flow-3D V12) and the depth and width of the meltpool are predicted. The obtained dimensions of the melt-track are then generalised based on the thickness of the TWS to confirm the accuracy of the simulation. The related rheological features of LB-PBF in the production of TWS are characterised and discussed from the results of the simulations. In this paper, the first experimentally validated simulation and experimentation of thin-walled surfaces are carried out with different inclination angles and the number of laser pass to identify the effect of these control factors, on dimensional deviation, distortion and porosity for the TWS. The meltpool phenomena for the thin wall structure are identified by fundamental rheological aspects and thermophysical properties of the material. Manufacturability and porosity are quantified for these conditions of interest, thereby providing fundamental phenomenological insight combined with practical design data for the application of TWS in LB-PBF. Results of this research show that the inclination angle and the number of laser passes in LB-PBF strongly drive the meltpool features, wall thickness, distortion and porosity. In LB-PBF of TWS, by changing the inclination angle the number of laser passes, the porosity, distortion and dimensional accuracy can be controlled.

ABSTRACT In the current work, sandwich structure (Ti-6Al-4V)-Ni-(Ti-6Al-4V) is printed by Laser Engineered Net Shaping (LENS). This sandwich structure allows the general repair of broken parts with dissimilar materials. The chief objective of this research is to propose a new method to produce a sandwich structure comprising Ti-6Al-4V and Nickel by DED, which allows the investigation of the Ti-6Al-4V/Nickel and Nickel/Ti-6Al-4V interfaces. The results shed light on the production process and makes a proper roadmap for multi-material printing. The contributions of this paper are the detailed defect characterization of (Ti-6Al-4V)-Ni-(Ti-6Al-4V) sandwich structures, considering the rheological phenomena in the meltpool and thermophysical properties of the materials. This research also identifies how the interface quality and the overall bonding quality of the sandwich structures can be improved, enabling the exploration of the limitations of production, and the knowledge of how to potentially produce a defect-free sandwich structure of Ti-Ni-Ti. Results showed that cracks, pores, partial melting, keyholes and residual particles are the main problems during a build. These results indicate that the LENS is a promising method to produce sandwich structures for various applications by selecting the appropriate process parameters in such a way as to minimize the rheological instability.

The purpose of this research is to develop a hybrid experimental and computational model to estimate the absorption of the laser for Laser-Based Powder Bed Fusion (LB-PBF) of IN718. The research also aims to find an underlying knowledge on the effect of absorption ratio on meltpool morphology. This model helps to improve the accuracy of the prediction of the meltpool morphology and the rheology of the melt tracks as well as the temperature-related phenomena in the process. In this paper, two test sets for the initial test with constant and dynamic/(process parameters dependent) absorption ratios were simulated. Melt tracks with different process parameters are printed and simulated from low to high energy density. Then, the Absorption Ratio (AR) is changed for each simulation until the same meltpool depth as the experimental results is obtained. In the next step, the temperature of the meltpool in the interaction area of the laser and material is measured from the performed simulations. Based on the obtained temperature and process parameters, a mathematical model is developed to estimate the absorption ratio in different conditions. The model is validated in hybrid computational and experimental conditions. The investigation provides the first model to calculate the absorption ratio in LB-PBF based on the temperature of the meltpool and process parameters. Results show that the developed model significantly enhances the accuracy of estimating meltpool features such as temperature, rheological and thermophysical properties of the material in the melting state.

One problematic task in the laser-based powder bed fusion (LB-PBF) process is the estimation of meltpool depth, which is a function of the process parameters and thermophysical properties of the materials. In this research, the effective factors that drive the meltpool depth such as optical penetration depth, angle of incidence, the ratio of laser power to scan speed, surface properties and plasma formation are discussed. The model is useful to estimate the meltpool depth for various manufacturing conditions. A proposed methodology is based on the simulation of a set of process parameters to obtain the variation of meltpool depth and temperature, followed by validation with reference to experimental test data. Numerical simulation of the LB-PBF process was performed using the computational scientific tool “Flow3D Version 11.2” to obtain the meltpool features. The simulation data was then developed into a predictive analytical model for meltpool depth and temperature based on the thermophysical powder properties and associated parameters. The novelty and contribution of this research are characterising the fundamental governing factors on meltpool depth and developing an analytical model based on process parameters and powder properties. The predictor model helps to accurately estimate the meltpool depth which is important and has to be sufficient to effectively fuse the powder to the build plate or the previously solidified layers ensuring proper bonding quality. Results showed that the developed analytical model has a high accuracy to predict the meltpool depth. The model is useful to rapidly estimate the optimal process window before setting up the manufacturing tasks and can therefore save on lead-time and cost. This methodology is generally applied to Inconel 718 processing and is generalisable for any powder of interest. The discussions identified how the effective physical factors govern the induced heat versus meltpool depth which can affect the bonding and the quality of LB-PBF components.

Abstract. The Hani peatland is one of the few that remain well-preserved in northeast China, which makes it a valuable site for paleoclimate research. Here, two sediment cores, which cover the past 13.8 ka, were collected, and loss on Ignition (LOI550°C) and X-ray Fluorescence Scanning (XRF) were carried out to build organic matter content and Rb/Sr ratio profiles, in order to assess the climate changes and associated East Asian Summer Monsoon (EASM) evolution since the last deglaciation. The results show that organic content and the chemical weathering index increased from the early to mid Holocene, possibly reflecting increased precipitation and an enhanced EASM. During the mid to late Holocene, the organic content and the chemical weathering index values decreased, implying that the EASM weakened. The variations of monsoon intensity during the Holocene derived from the Hani peat are consistent with the EASM reconstructions from the Gonghai, Daihai, Qinghai Lake, Hexiazi Island and the Yulin loess-paleosol section. Thus the Hani and other published EASM records from northern China demonstrate that the evolution of EASM during the Holocene was likely to be dominated by the combination of the influences from changing solar insolation and northern hemisphere ice volumes. In addition, a 0.5–2 ka band filtering analysis of LOI550°C data show that millennial scale climate changes in northeast China were teleconnected with the North Atlantic ice-rafted debris and solar irradiance records, indicating that both North Atlantic climate changes and solar activity probably affected EASM variations.

Layered rare earth compounds in the RMn2X2 series (R = rare‐earth; X = Ge, Si) are of interest for potential cooling applications at lower temperatures as they enable the structural and magnetic behavior to be controlled via substitution of R, Mn, and X atoms on the 2a, 4d, and 4e sites respectively. We continue investigations of the Pr1−xYxMn2Ge2 magnetic phase diagram as functions of both composition and Mn–Mn spacing using X‐ray and neutron diffraction, magnetization and differential scanning calorimetry measurements. Pr1−xYxMn2Ge2 exhibits an extended region of re‐entrant ferromagnetism around x ∼ 0.5 with re‐entrant ferromagnetism at for Pr0.5Y0.5Mn2Ge2. The entropy values −ΔSM around the ferromagnetic transition temperatures from the layered antiferromagnetic AFl structure to the canted ferromagnetic structure Fmc (typically ) have been derived for Pr1−xYxMn2Ge2 with x = 0.0, 0.2, and 0.5 for ΔB = 0–5 T. The changes in magnetic states due to Y substitution for Pr are discussed in terms of chemical pressure, external pressure, and electronic effects.

The effects of high hydrostatic pressure on the structure and dynamics of model membrane systems were investigated using neutron scattering. Diffraction experiments show shifts of the pre- and main-phase transitions of multilamellar vesicles of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) to higher temperatures with increased pressure which are close to results observed previously by other techniques, namely (10.4 ± 1.0) K kbar(-1) and (20.0 ± 0.5) K kbar(-1) for the two transitions. Backscattering spectroscopy reveals that the mean square displacements in the liquid phase are about 10% smaller at 300 bar and about 20% smaller at 600 bar compared to atmospheric pressure, whereas in the gel phase below the main phase transition the mean square displacements show a smaller difference in the dynamics of the three pressure values within the studied pressure range.

Abstract The aim of this chapter is to show how inelastic and quasielastic neutron scattering can be used to study dynamics in a range of materials varying from simple model systems to complex systems that are close to those used in technologically important applications. After a brief overview of the theoretical and instrumental concepts, we use examples to show how different types of atomic and molecular motions can be understood using neutron scattering experiments, frequently in combination with atomistic modeling methods. We cover aspects of physics, chemistry, biology, and materials science, but with the main focus on functional materials.