Ms Values Research Articles

DS based 2-DOF PID controller for various integrating processes with time delay

This study proposes a direct synthesis-based two-degree-of-freedom (2-DOF) controller for various types of integrating processes with time delays. This 2-DOF controller includes a proportional-integral-derivative (PID) controller to enhance load disturbance rejection performance and a set-point filter to improve servo response performance. The main PID controller parameters are expressed as process model parameters and a single adjustment variable, while the set-point filter is composed of PID controller parameters with weighted factors. The adjustment variable is tuned to achieve an optimal balance between response performance and robustness, based on the maximum magnitude of the sensitivity function (Ms). Controller parameters for various Ms values and guidelines for setting these parameters are provided in a consistent formulaic form using a curve-fitting method. These parameter-setting formulas facilitate the accurate implementation of PID controllers with specified Ms values and allow the controller design to be extended to processes with larger dimensionless time delays for a given Ms value. Although a 2-DOF controller was proposed, the adjustment variable for setting the parameters of the main PID controller and the set-point filter was solely the desired time constant. The proposed method was applied to various integrating processes with time delays, and its performance was compared with existing methods reported in the literature, based on performance indices such as settling time, overshoot, integral of absolute error, total variation in input usage, and global performance index. Simulations were conducted using six examples of various integrating processes with time delays to verify the effectiveness and applicability of the proposed controller.

Study on the electromagnetic properties and microwave absorption properties of Co2Si by non-magnetic metal Cu and Mn single doping

In this study, Co2Si and Co2Si-doped powder materials with different Cu,Mn proportions were prepared by mechanical alloying and thermal sintering. The effects of Cu,Mn doping on the crystal structure, magnetic properties, and microwave absorption properties of Co2Si were investigated. The results showed that all the sample peaks obtained by XRD measurement were consistent with the standard card (ICDD: 98–005–2281) of Co2Si.The Ms values corresponding to 2 at%, 4 at%, and 8 at% Cu doping were 25.79 emu/g, 23.79 emu/g, and 21.75 emu/g, respectively. The saturation magnetization of Co2Si samples doped with 2 at%, 4 at% and 8 at% Mn was 8.26 emu/g, 20.33 emu/g and 14.65 emu/g, respectively.The doping of Cu significantly improved the comprehensive absorption performance of Co2Si alloy, and the lowest reflection loss was obtained when Cu was doped with Co2Si alloy, with an RLmin value of -67.61 dB and an EAB of 2.40 GHz. The comprehensive absorption performance of Mn doped Co2Si was also improved, and the RLmin value of Mn doped with 4 at% was -67.04 dB, and the EAB was 2.39 GHz.This is because that the small Co2-xMxSi (M=Cu,Mn) alloy can produce multiple reflection and scattering effects, which increase the propagation path of the electromagnetic wave and optimize the impedance matching characteristics of the material.

The role of Cu element in Fe9.4Co6.7Ni6.6Mn0.9V0.9Cu2.4 magnetic high-entropy alloys

Spark plasma sintering (SPS) technology has obvious advantages in the preparation of high entropy alloys (HEAs) with high mechanical properties, but the mechanism of their magnetic enhancement is not clear. In this work, HEAs with high saturation magnetization (Ms) and excellent mechanical properties were designed and prepared. The properties of Fe9.4Co6.7Ni6.6Mn0.9V0.9 HEA were optimized by adding Cu element, and the main phase of the HEAs was (face-centered cubic) FCC phase. The addition of Cu element mitigates the distortion of the FCC phase, resulting in an increase in the intensity of Ms value for the alloy from 118 emu/g to 143.7 emu/g. However, this also leads to a slight reduction in yield strength while still maintaining a high level at 1132 MPa. Theoretical calculations based on first principles indicate that the magnetic enhancement of these alloys is facilitated by an increase in the atomic magnetic moments of their ferromagnetic constituents.

Investigation of superparamagnetic iron oxide nanoparticles in air environment for elevated saturation magnetization

Iron oxide nanoparticles have garnered interest for their unique properties and wide application areas. For applications, superparamagnetic nanoparticles are required so that they can be magnetized by an external magnetic field and rapidly demagnetize again when the field is removed. High saturation magnetization, Ms is also required for applications to provide easy magnetic control over separation and targeting. For magnetically controlled applications, superparamagnetic iron oxide nanoparticles with a high Ms are important. In this study, superparamagnetic iron oxide nanoparticles were co-precipitated under air atmosphere and the effects of alkali concentration, stirring rate and reaction time on the structural and related magnetic properties were investigated to obtain the high Ms for each parameter. According to the structural results, it is challenging to obtain magnetite nanoparticles under air atmosphere due to oxidizing effect. The increase of Ms values with the increase of alkali concentration may come from the phase of the samples although the crystal size of the nanoparticles is getting smaller. It can be said that there is an optimum stirring rate to obtain the highest Ms under air atmosphere rather than an uptrend/downtrend. The maximum Ms of 69.2 emu g−1 was obtained for superparamagnetic iron oxide nanoparticles synthesized at 700 rpm. With the increase of reaction time, magnetic size of the nanoparticles is observed to decrease in contrast with the increase of physical particle size. The maximum Ms value for the reaction time parameter is 67.3 emu g−1 at 15 min. Due to their high Ms values and superparamagnetic nature, the nanoparticles synthesized under study may find use in magnetic separation, water purification, and other related fields.

Superparamagnetic hydrophilic molecularly imprinted nanoparticles for an efficient and selective removal of tetracycline from water

In this work, a novel superparamagnetic hydrophilic molecularly imprinted nanomaterial for the removal of tetracycline (TC) was synthesized utilizing magnetite (Fe3O4) as the magnetic core, TC as the template molecule, 3-aminopropyltriethoxysilane (APTES) as the functional monomer, and tetraethoxysilane (TEOS) as the cross-linker. Initially, Fe3O4 magnetic nanoparticles (MNP) coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. Initially, Fe3O4 MNP coated with SiO2 (MNP@SiO2) were synthesized, followed by TC molecular imprinting on the nanoparticles. The synthesis method for MNP@SiO2 was optimized, and DLS analysis of 10 replicates showed a nanoparticle size of 70.1 ± 5.8 nm, indicating high method reproducibility. The MNP@SiO2, as well as the imprinted (MNP@SiO2-MIP) and non-imprinted (MNP@SiO2–NIP) nanomaterials, were characterized by FTIR, TEM, VSM, XRD, DLS, Z potential, and BET analysis. The saturation magnetization (Ms) values were 43 emu/g for MNP@SiO2 and 32 emu/g for both MNP@SiO2-MIP and MNP@SiO2–NIP, confirming suitability for magnetic separation using external magnets. Batch binding experiments conducted in water and methanol assessed adsorption isotherms and binding kinetics, with data fitting the Langmuir isotherm model better than the Freundlich model. The developed MIP exhibited significant selectivity against other molecules with similar functional groups and size. In water, the adsorption capacity of the MNP@SiO2-MIP was 23 mg/g, with an imprinting factor of 2.2. Furthermore, the MIP demonstrated good regeneration performance. The material was tested on TC-spiked tap water samples, achieving 80.1 % TC removal with high reproducibility (3.2 %, n = 3). Combining hydrophilic superparamagnetic nanoparticles with molecular imprinting enhances their potential applications in environmental remediation, antibiotic purification, and drug delivery.

Predictive modelling of laser powder bed fusion of Fe-based nanocrystalline alloys based on experimental data using multiple linear regression analysis

This study harnessed bivariate correlational analysis, multiple linear regression analysis and tree-based regression analysis to examine the relationship between laser process parameters and the final material properties (bulk density, saturation magnetization (Ms), and coercivity (Hc)) of Fe-based nano-crystalline alloys fabricated via laser powder bed fusion (LPBF). A dataset comprising of 162 experimental data points served as the foundation for the investigation. Each data point encompassed five independent variables: laser power (P), laser scan speed (v), hatch spacing (h), layer thickness (t), and energy density (E), along with three dependent variables: bulk density, Ms, and Hc. The bivariate correlational analysis unveiled that bulk density exhibited a significant correlation with P, v, h, and E, whereas Ms and Hc displayed significant correlations exclusively with v and P, respectively. This divergence may stem from the strong influence of microstructure on magnetic properties, which can be impacted not only by the laser process parameters explored in this study but also by other factors such as oxygen levels within the build chamber. Furthermore, our statistical analysis revealed that bulk density increased with rising P, h, and E, while decreased with higher v. Regarding the magnetic properties, a high Ms was achievable through low v, while low Hc resulted from high P. It was concluded that P and v were considered as the primary laser process parameters, influencing h and t due to their control over the melt-pool size. The application of multiple linear regression analysis allowed the prediction of the bulk density by using both laser process parameters and energy density. This approach offered a valuable alternative to time-consuming and costly trial-and-error experiments, yielding a low error of less than 1 % between the mean predicted and experimental values. Although a slightly higher error of approximately 6 % was observed for Ms, a clear association was established between Ms and v, with lower v values corresponding to higher Ms values. Additionally, a further comparison was conducted between multiple linear regression and three tree-based regression models to explore the effectiveness of these approaches.

Single-point and kinetics of peripheral residual disease by mass spectrometry to predict outcome in patients with high risk smoldering multiple myeloma included in the GEM-CESAR trial.

The value of quantitative immunoprecipitation mass spectrometry (QIP-MS) to identify the M-protein is being investigated in patients with monoclonal gammopathies but no data are yet available in high-risk smoldering myeloma (HRsMM). We have therefore investigated QIP-MS to monitor peripheral residual disease (PRD) in 62 HRsMM patients enrolled in the GEM-CESAR trial. After 24 cycles of maintenance, detecting the M-protein by MS or clonal plasma cells by NGF identified cases with a significantly shorter median PFS (mPFS; MS: not reached vs 1,4 years, p=0.001; NGF: not reached vs 2 years, p=0.0002) but reaching CR+sCR did not discriminate patients with different outcome. With NGF as a reference, the combined results of NGF and MS showed a high negative predictive value (NPV) of MS: 81% overall and 73% at treatment completion. When sequential results were considered, sustained negativity by MS or NGF was associated with a very favorable outcome with a mPFS not yet reached vs 1.66 years and 2.18 years in cases never attaining PRD or minimal residual disease (MRD) negativity, respectively. We can thus conclude that 1) the standard response categories of the IMWG do not seem to be useful for treatment monitoring in HRsMM patients, 2) MS could be used as a non-invasive, clinical valuable tool with the capacity of guiding timely bone marrow evaluations (based on its high NPV with NGF as a reference) and 3) similarly to NGF, sequential results of MS are able identify a subgroup of HRsMM patients with long-term disease control. This study was registered at www.clinicaltrials.gov (ClinicalTrials.gov identifier: NCT02415413).

Prediction of martensitic transformation start temperature of steel using thermodynamic model, empirical formulas, and machine learning models

Three methods are used to predict the martensitic transformation start temperature (Ms ) of steel. Based on the database containing 832 compositions and corresponding Ms data, prediction models are built, modified, and trained. Firstly, Ms was re-calculated by establishing a thermodynamic model to link the martensitic transformation driving force (Gibbs free energy difference of martensite and austenite) with resistance (elastic strain energy, plastic strain energy, interface energy, and shearing energy). Secondly, the existing Ms data is cleaned and re-predicted using traditional empirical formulas within different composition application ranges. Thirdly, four different algorithms in machine learning including random forest, k nearest neighbor, linear regression, and decision tree are trained to predict 832 new Ms values. By comparing the Ms results re-predicted by the mentioned three methods with the original Ms values, the accuracy is evaluated to identify the optimal prediction model.

Dense Contaminants Mixing Into the Saltwater Wedge in Coastal Aquifers: Laboratory and Numerical Investigations

AbstractThe saltwater‐freshwater mixing zones in coastal aquifers can host complex physical exchange and biogeochemical transformations. The land‐sourced dense contaminant plumes could be transferred into the mixing zone of the saltwater wedge due to the density effect prior to discharge to the sea. However, the mixing process between dense contaminants and the saltwater wedge has not received much attention, largely due to the lack of physical evidence. This study used laboratory experiments and numerical simulations to investigate the transport and discharge behaviors of variable‐density contaminant plumes in tidally influenced unconfined coastal aquifers. Results demonstrate that the highly dense contaminants mix with the underlying saltwater and finally merge with the saltwater wedge. This process significantly extends the contaminant discharge durations, thereby reducing the peak value of contaminant efflux. The dense contaminants are elongated along the landward margin of the saltwater wedge, leading to a larger spreading area (Ms) than that of constant‐density contaminants. The sensitivity analysis indicates that the high density of contaminants acts as a trigger to induce the mixing of them and wedges. The higher hydraulic conductivity, lower dispersivities and reduced inland freshwater flux significantly increase the residence times (Rt) and discharge duration (Dt) by enhancing the mixing of dense contaminants with seawater. In contrast, both Rt and Dt values are not only non‐monotonic functions of tidal amplitudes but also less sensitive to tidal effects. Compared with the non‐tidal condition, however, the addition of tides significantly increases both Rt and Ms values of dense contaminant plumes. The results presented herein provide valuable insights into the mechanisms of dense contaminants mixing into saltwater wedges, which could guide practitioners in designing effective strategies to protect coastal environments from land‐sourced contaminants.

Stabilizing magnetic order of cobalt-based anisotropic nanoparticles prepared using NaBH4 as a reducing agent

A one-pot chemical method was used to prepare cobalt nanoparticles (Co NPs) by employing sodium borohydride (NaBH4) as a reducing agent, as well as graphite and activated carbon as stabilizer materials. The resulting NPs were characterized by XRD, FE-SEM, EDX mapping and VSM measurements before and after annealing under a mixture of argon and hydrogen atmosphere at 600 ℃, in order to study their structural, morphological, and magnetic properties. This study focused on the shape and size of Co NPs, involving the formation of Co and Co3O4 phases with the effect of oxygen as the main factor that can significantly contribute to the magnetic anisotropy. Co NPs exhibited a high saturation magnetization (Ms) value after performing the annealing process, achieving Ms> 99 emu/g when using the graphite stabilizer. The results indicate that surface atoms play a significant role in the modification of magnetic characteristics of Co NPs.

Effects of La-Co Co-Substitution and Magnetic Field Pressing on the Structural and Magnetic Properties of SrM Hexaferrites

We carefully investigated the effects of La-Co co-substitution and magnetic field pressing (MFP) on the structural and magnetic properties of SrM hexaferrites. Samples composed of Sr1−xLaxFe12−xCoxO19 were sintered at 1230 °C for 2 h in air with sintering additives composed of 0.7 wt% CaCO3 and 0.7 wt% SiO2. A single M-type phase was confirmed to exist up to x = 0.3. Rietveld refinement revealed a slight decrease in lattice parameter a and the unit cell volume (Vcell) with an increasing x, while parameter c showed a significant decrease. The saturation magnetization (Ms) values increased from 70.90 to 72.40 emu/g with an increasing x from 0.0 to 0.15 and then decreased to 71.38 emu/g with further increasing of x to 0.3, while the anisotropy field (Ha) increased from 17.7 to 25.9 kOe, leading to a continuous increase in the intrinsic coercivity (Hci), from 3.52 to 5.00 kOe, respectively. Using the MFP process, the c-axis of M-type hexaferrite grains could be effectively aligned to the applied field direction, which significantly affected the microstructures and, thus, magnetic properties of samples. Unlike non-MFP samples, exhibiting a significant increase in the average grain size (davg) but almost unaltered average thickness (tavg) with an increasing x from 0.0 to 0.3, MFP-processed samples exhibited almost unaltered davg values but a continuous decrease in tavg. Consequently, the variation in remanent flux density (Br) versus x followed that of Ms versus x and thus exhibited the highest Br of 4.05 kG for x = 0.15, leading to the highest maximum energy product {(BH)max} of 3.62 MGOe. With an increasing x from 0.0 to 0.3, the Hci values continuously increased from 3.14 to 3.84 kOe mainly due to a continuous increase in Ha, although they were significantly lowered in comparison with those of non-MFP samples because of a large increase in Br for a given composition x. A higher Mr/Ms ratio always resulted in a larger (BH)max in our samples regardless of x. A careful comparison of the microstructures and magnetic properties between MFP and non-MFP samples provided valuable insights into a broad area of permanent magnet optimization.

Study of the Preparation and Performance of TiO2-Based Magnetic Regenerative Adsorbent.

Against the backdrop of "carbon neutrality", the green treatment of dye wastewater is particularly important. Currently, the adsorption method shows strong application prospects. Therefore, selecting efficient and recyclable adsorbents is of significant importance. TiO2 is an excellent adsorbent, but its difficult recovery often leads to secondary pollution. γ-Fe2O3-modified coal-series kaolin exhibits both excellent adsorption properties and rapid separation through magnetic separation technology. By utilizing the synergistic effects of both, TiO2/-γFe2O3 coal-series kaolin, magnetic adsorbent regeneration materials were prepared using coprecipitation method and characterized. The influencing factors of this functional material on the adsorption of Congo red dye and its regeneration performance are discussed. The experimental results indicated that the specific surface area, pore volume and Ms value of this functional material are 127.5 m2/g, 0.38 cm3/g, and 13.4 emu/g, respectively. It exhibits excellent adsorption characteristics towards Congo red, with an adsorption rate reaching 96.8% within 10 min, conforming to the pseudo-second-order kinetic model, and demonstrating Langmuir IV-type monolayer adsorption. After the adsorption of Congo red, magnetic separation shows superior efficiency. Furthermore, treatment of the adsorbed composite with EDTA allows for recycling, with adsorption rates still above 91% after three cycles, indicating an excellent regeneration capability.

In–Sn–Cu co-doped yttrium iron garnet ferrite: Magnetic and dielectric properties

With the miniaturization and integration of electronic components, there has been widespread attention on yttrium iron garnet ferrite (YIG) with high saturation magnetization, high dielectric constant, and low ferromagnetic resonance linewidth. In this work, In–Sn–Cu co-doped YIG ferrite with the chemical formula Y3Fe4.8-xCu0.1Sn0.1InxO12 (x = 0.05, 0.10, 0.20, 0.30) was prepared. The properties of the samples, including their microstructure, crystal structure, magnetic attributes, and dielectric properties, were adjusted through the regulation of the indium doping levels. The microscopic and crystal structures confirm the effective doping of ions in YIG, resulting in an expansion of the lattice parameters. Both the saturation magnetization (Ms) and the ferromagnetic resonance linewidth (ΔH) are influenced by the level of doping. The maximum value of Ms is observed at x = 0.10 (30.86 emu/g), whereas the minimum value of ΔH occurs at x = 0.20 (35 Oe). Additionally, increasing doping concentration also leads to an upward trend in both resistivity and dielectric constant, with the lowest dielectric loss occurring at x = 0.15. This study will provide an effective approach for developing high-performance YIG ferrite that meets the requirements of miniaturization and integration.

Exploring the structural and magnetic properties of La-doped nickel ferrite for microwave absorbing application

The intrinsic properties of microwave absorbing materials are influenced by the permeability and permittivity of the material with indicators of changes in reflection loss characteristics. Nickel ferrite is a magnetic material with very high permeability, so the presence of La3+ ion substitution in nickel ferrite can increase the permittivity of this material and is denoted by increased reflection loss. The magnetic material NiLaxFe(2−x)O4 was synthesized effectively through co-precipitation techniques using NiCl2, FeCl3, and LaCl3 powders, with mole ratios varying from x = 0.01 to 0.04, then continued with the sintering process at a temperature of 1200 °C for 5 h.The X-ray diffraction (XRD) analysis indicates that all NiLaxFe(2−x)O4 samples consist of a single phase of NiFe2O4 with a cubic spinel structure. The scanning electron microscope (SEM) image of NiLaxFe(2−x)O4 powders reveals that all samples exhibit a consistent morphology, however, the powder doesn’t look uniform yet, with particle sizes ranging from 100-800 nm. The magnetic properties of the samples were examined using a vibrating sample magnetometer (VSM). The sample shows ferromagnetic behavior, but the Ms value decreases from 35.89 to 21.54 emu/g and the Hc value increases from 249 to 416 Oe as the La3+ ion content in the material increases. Meanwhile, the microwave absorption capacity measured using the vector network analyzer (VNA) shows that reflection loss increases from 11.16 dB to 15.41 dB as the La3+ ion content in the material increases. So, the substitution of La3+ ions in nickel ferrite structure up toa concentration of x = 0.04 can increase microwave absorption up to 97.11 %.

Structural, magnetic and photoluminescence properties of Zn-Ni ferrites synthesized by hydrothermal method

Nanocrystalline ZnxNi1-xFe2O4 (0 ≤ x ≤ 1.0) ferrites were synthesized by hydrothermal method. XRD analysis showed that all compositions crystallize with a cubic spinel-type structure with an average crystallite size in the range of 17–27 nm which corresponded to particle sizes obtained from TEM. The lattice parameter increased from 8.289 to 8.432 Å with increasing Zn content. The ZnxNi1-xFe2O4 nanoferrites exhibit superparamagnetic behaviour at room temperature (RT). The saturation magnetization (Ms) varies considerably with Zn content to reach a maximum value for Zn0.5Ni0.25Fe2O4 composition, i.e. 41.893 emu/g. The high Ms and magnetic moment values are attributed to cation distribution change. The electron spin resonance (ESR) results demonstrated g-values ranging between 2.005 and 2.621 which indicated strong exchange interaction between nanoparticles, type of morphology, and crystalline nature of particles. These low g-values make ZnxCo1-xFe2O4 nanoferrites suitable for applications in low-frequency devices. The Mössbauer spectroscopy results revealed the transition from ferromagnetic to paramagnetic state, by showing collapse of sestet to quadrupole doublet. The optical properties of the nanoferrites were investigated photoluminescence (PL) spectra. The broad visible emission band at 427 nm (2.90 eV), 471 nm (2.60 eV) and 520 nm (2.38 eV) were observed in all PL spectra. The electron spin resonance and photoluminescence results show that Zn-Ni ferrites are good candidates for blue LEDs and in gas sensing applications.

Navigator-based motion compensation for liver BOLD measurement with five-echo SAGE EPI and breath-hold task.

The purpose of this work is to apply multi-echo spin- and gradient-echo (SAGE) echo-planar imaging (EPI) combined with a navigator-based (NAV) prospective motion compensation method for a quantitative liver blood oxygen level dependent (BOLD) measurement with a breath-hold (BH) task. A five-echo SAGE sequence was developed to quantitatively measure T2 and T2* to depict function with sufficient signal-to-noise ratio, spatial resolution and sensitivity to BOLD changes induced by the BH task. To account for respiratory motion, a navigator was employed in the form of a single gradient-echo projection readout, located at the diaphragm along the inferior-superior direction. Prior to each transverse imaging slice of the spin-echo EPI-based readouts, navigator acquisition and fat suppression were incorporated. Motion data was obtained from the navigator and transmitted back to the sequence, allowing real-time adjustments to slice positioning. Six healthy volunteers and three patients with liver carcinoma were included in this study. Quantitative T2 and T2* were calculated at each time point of the BH task. Parameters of t value from first-level analysis using a general linear model and hepatovascular reactivity (HVR) of Echo1, T2 and T2* were calculated. The motion caused by respiratory activity was successfully compensated using the navigator signal. The average changes of T2 and T2* during breath-hold were about 1% and 0.7%, respectively. With the help of NAV prospective motion compensation whole liver t values could be obtained without motion artifacts. The quantified liver T2 (34.7 ± 0.7 ms) and T2* (29 ± 1.2 ms) values agreed with values from literature. In healthy volunteers, the distribution of statistical t value and HVR was homogeneous throughout the whole liver. In patients with liver carcinoma, the distribution of t value and HVR was inhomogeneous due to metastases or therapy. This study demonstrates the feasibility of using a NAV prospective motion compensation technique in conjunction with five-echo SAGE EPI for the quantitative measurement of liver BOLD with a BH task.

Effect of Steel Slag on the Properties of Alkali-Activated Slag Material: A Comparative Study with Fly Ash.

Slag and fly ash (FA) are mostly used as precursors for the production of alkali-activated materials (AAMs). FA is the waste discharged by power plants, while slag and steel slag (SS) both belong to the iron and steel industry. The effects of SS and FA on the strength, microstructure, and volume stability of alkali-activated slag (AAS) materials with different water glass modulus (Ms) values were comparatively investigated. The results show that adding SS or FA decreases the compressive strength of AAS mortar, and the reduction effect of SS is more obvious at high Ms. SS or FA reduce the non-evaporable water content (Wn) of AAS paste. However, SS increases the long-term Wn of AAS paste at low Ms. The cumulative pore volume and porosity increase after adding SS or FA, especially after adding FA. The hydration products are mainly reticular C-(A)-S-H gels. Adding SS increases the Ca/Si ratio of C-(A)-S-H gel but decreases the Al/Si ratio. However, by mixing FA, the Ca/Si ratio is reduced and the Al/Si ratio is almost unchanged. The incorporation of SS or FA reduces the drying shrinkage of AAS mortar, especially when SS is added. Increasing Ms increases the compressive strength and improves the pore structure, and it significantly increases the drying shrinkage of all samples. This study provides theoretical guidance for the application of steel slag in the alkali-activated slag material.

Performance of T2 mapping in the staging of Graves' ophthalmopathy based on different region of interest selection methods.

Discriminating the stage of Graves' ophthalmopathy (GO) is crucial for clinical decision. Application of conventional T2-weighted imaging in the staging is still limited. To evaluate the performance of T2 mapping based on two different regions of interest (ROIs) for staging GO. In total, 56 GO patients were retrospectively enrolled and divided into two groups according to the clinical activity score (CAS). T2 relaxation time (T2RT) of extraocular muscle (EOM) on T2 mapping based on two different ROIs (T2RTROI-1: ROIs were drawn separately in the four EOMs; T2RTROI-2: ROI was drawn in the most inflamed EOM) was measured and compared between active and inactive groups. Both T2RTROI-1 and T2RTROI-2 values in the active GO were significantly higher than those of inactive GO (P <0.001). T2RTROI-1 and T2RTROI-2 values were positively correlated with CAS (rs=0.73, 0.69; P <0.001). When the T2RTROI-1 value of 83.3 ms and T2RTROI-2 value of 106.3 ms were used as cutoff values for staging GO, respectively, the best results were obtained with areas under the curve (AUCs) of 0.822 and 0.827. There was no significant difference for AUCs between T2RTROI-1 and T2RTROI-2 (P = 0.751). Excellent and good inter-observer agreements were achieved in quantitative measurements for T2RTROI-1 and T2RTROI-2 values, respectively, with intraclass correlation coefficients of 0.954 and 0.882. The T2RT values derived from two different ROIs were useful for assessment of disease activity. Taking reproducibility and diagnostic performance into consideration, T2RTROI-1 would be an ideal image biomarker for staging GO compared to T2RTROI-2.

Structural properties controlled magnetisation of Ni/Al multilayers sputtered on flexible polymer substrate: Impact of Ni deposition rates

The goal of this work is to determine how the rate of Ni deposition rates affect the structural characteristics that regulate the magnetization of Ni/Al multilayer thin films sputtered on flexible acrylic acetate polymer substrates. The films with a 5[Ni(20 nm)/Al(10 nm)] structure were gradually sputtered as different Ni deposition rates in the total thickness of 150 nm. With an increase in the rate of Ni deposition, the Ni contents increased from 61.5% to 69.6%. And, X-ray diffraction analysis verified that the films featured a face-centered cubic structure with variable peak intensities. Also, the scanning electron microscopy surface morphology analyses revealed that variations in the film surfaces were a result of the deposition rates. For magnetic measurements, the differences in the structural analysis were observed to cause a notable variation in saturation magnetization, MS, and coercivity, HC values. Accordingly, MS values increased consistently between 359.0 and 389.7 emu cm−3, but HC values decreased from around 34–32 to 28 Oe with the increase in Ni deposition rate from 0.02 to 0.10 nm s−1. It is also observed that when the Ni layers are generated at very fast deposition rates, the Ni/Al multilayer films have a high MS/HC ratio, which is significant for magnetic sensors. It has been concluded that the magnetisation of Ni/Al multilayer thin films can be controlled by the structural properties adjusting the Ni deposition rate.

Production of High-Coercive nanostructured Nd-Fe-B alloy by chemical method

For the first time, a nanostructured alloy powder with high coercive force was obtained by a chemical method without the addition of Dy, which can compete with physical methods of production. The work carried out a study of the influence of stoichiometric composition on the magnetic properties of nanostructured Nd-Fe-B alloys. Alloys with different contents of Nd, Fe, and B were synthesized: Nd12Fe84B6, Nd14Fe80B6, Nd16Fe76B8, and Nd16Fe72B8. With a decrease in the iron content in the first two compositions, a decrease in the iron content in the soft magnetic phase α-Fe was observed, which led to an increase in the coercive force Hc and a decrease in the values of Ms and Mr. Experiments have shown that an increase in the content of Nd and B promotes the formation of the hard magnetic phase Nd2Fe14B and an increase in the coercive force. For example, the nanostructured Nd16Fe76B8 alloy demonstrated a maximum coercive force of Hc = 8439 Oe, while compensating for the values of Ms (109 emu*g−1) and Mr (78 emu*g−1). A comprehensive study of the nanostructured Nd16Fe76B8 alloy was carried out, including structural analysis. XRD using FullProff and Vesta software revealed the tetragonal crystal structure of the Nd2Fe14B phase, providing details of the atomic arrangement. The unit cell contains four layers with Nd and Fe atoms, and boron atoms are embedded in the center of the octahedron of Nd and Fe atoms, playing an important role in the magnetic exchange interaction. The results of Mössbauer spectroscopy confirmed the presence of the Nd2Fe14B phase and revealed details of the state of Fe atoms in the structure of six sextets.