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Clinker free lime (f-CaO) content plays a crucial role in determining the quality of cement. However, the existing methods are mainly based on laboratory analysis and with significant time delays, which makes the closed-loop control of f-CaO content impossible. In this paper, a multisource data ensemble learning-based soft sensor model is developed for online estimation of clinker f-CaO content. To build such a soft sensor model, input flame images, process variables, and the corresponding output f-CaO content data for a rotary cement kiln were collected from No. 2 rotary kiln at Jiuganghongda Cement Plant which produces 2000 tonnes of clinker per day. The raw data were preprocessed to distinguish the flame image regions of interest (ROI) and remove process variable outliers. Three types of flame image ROI features, i.e., color, global configuration, and local configuration features, were then extracted without segmentation. Further, a kernel partial least square technique was applied for extracting the compressed score matrix features from the concatenated flame image features and filtered process variables to avoid high-dimensional, nonlinear, and correlated problems. Feed-forward neural networks with random weights were employed as base learners in our proposed ensemble modeling framework, which aims to enhance the model’s reliability and prediction performance. A total of 157 flame images, the associated process variable data, and the experimentally measured f-CaO content data were used in our experiments. A comparative study on the f-CaO content estimator built by various feature compressed techniques and learner models and robustness analysis were carried out. The results indicate that the proposed multisource data ensemble soft sensor model performs favorably and has good potential in real world applications. [ABSTRACT FROM AUTHOR]

The effect of the addition of niobium oxide (NbO2) on the critical current density of large, single grain bulk YBCO superconductors fabricated by top seeded melt growth (TSMG) has been investigated. The high field critical current density, Jc, of NbO2 doped YBCO is improved significantly even though Jc in the low field region is generally lower than in undoped samples. Under these conditions, when field is applied parallel to the c-axis (H//c), Jc is enhanced by more than an order of magnitude at 4 T at 77 K to 2 x 103 A/cm2 for the NbO2 containing sample. This enhancement in J. is accompanied by a large increase in irreversibility field, Hirr, from 4 T for the undoped sample to over 6 T. Enhanced flux pinning at high field is due to the formation of a nano-scale Nb-rich phase during high temperature sintering, melting and solidification of the bulk superconductor. [ABSTRACT FROM AUTHOR]

We investigated on microstructure and superconducting properties of high-density MgB2 superconductors synthesized by a heat-treatment method combining a short period of sintering at 1100°C with a following annealing at a low temperature. The two-step sintering method was found to achieve a coexistence of a high density and broadened XRD full width at half maximum (FWHM) of MgB2 peak in the samples. The onset of diamagnetism at 5 T was approximately 2 K higher than those of the samples heat-treated by single-step sintering at high or low temperatures. Different second-step annealing temperatures were examined in this work. Microstructural analysis indicates that a lower second-step annealing temperature led to further suppression of the large grain growth in the MgB2 samples, which is beneficial to the pinning property of the samples. The energy loss peaks of ac susceptibility measurement in fields confirm that by decreasing the second-step sintering temperature flux pinning of MgB2 in high fields was enhanced. [ABSTRACT FROM AUTHOR]

MgB2 superconductors were made with two processes in this work. In one case, the SiC doped MgB2 pellets were sintered in excessive Mg medium. It is found that the samples sintered in excessive Mg medium present Mg-rich composition comparing with the one sintered in Ar gas. The density is higher and the resistance is lower due to the penetration of the Mg into the pores and grain boundary of MgB2, which is beneficial to the Jc improvement. In the other case, a two-step process was employed to make MgB2. Jc, of the sample with the composition of MgB4 is very low after the first sintering. The Jc. was dramatically improved after the second sintering, but J. of the two-step made sample is still poorer than the MgB2 made with general one step sintering due to the connectivity deterioration caused by the pulverization prior to the second sintering. [ABSTRACT FROM AUTHOR]

Selective laser sintering (SLS) is a powerful manufacturing technology that does not require part-specific tooling or significant human intervention and provides the ability to easily generate parts with complex geometric designs. The present work focuses on developing a manufacturing framework using this technology to produce subject-specific transtibial amputee prosthetic sockets made of Duraform PA, which is a nylon-based material. The framework includes establishing an overall socket design (using the patellar-tendon bearing approach), performing a structural analysis using the finite element method (FEM) to ensure structural reliability during patient use, and validating the results by comparing the model output with experimental data. The validation included quantifying the failure conditions for the socket through a series of bending moment and compression tests. In the case study performed, the FEM results were within 3% of the experimental failure loads for the socket and were considered satisfactory. [ABSTRACT FROM AUTHOR]

Reports on the influence of sintering conditions on the flashover and pre-flashover characteristics of alumina insulators in vacuum under an impulse voltage. Overall performance of an insulation system in vacuum; Description of the electrode-sample configuration; Electrical performance of different samples.

Presents information on a study which examined processing technologies that developed high performance neodymium-iron-boron sintered magnets. Methodology of the study; Results and discussion.

Observations were made on the Bi(2223) tapes undergoing uniaxial pressing (up to 5.7 GPa), CIPing (up to 2.5 GPa) and rolling combined with sintering. Tapes were fabricated utilizing drawing and flat rolling. They have shown strong textures for press- and roll-sintering modes of working and have indicated that CIPing improves effectively the core density, but if not accompanied by pre-annealing, it is not able itself to improve the core texturing. The FWHM of the rocking curves was measured to evaluate texturing degree and its dependence on the measurement geometry was emphasized. [ABSTRACT FROM PUBLISHER]

Presents a study which formed sintered neodymium-iron-boron magnets using powder metallurgy. Experimental details; Results and discussion; Conclusion.

Presents a study which investigated the maximum thermal remagnetization in sintered hard magnets. Methodology; Results; Discussion.

Presents a study which compared the corrosion rates for sintered neodymium iron boron magnets (NdFeB) with NdFeB magnets prepared from melt spun material. Methodology; Results and discussion; Conclusions.

Presents information on a study which examined the effect of the addition of silver powder to the magnetic properties and microstructure of NdFeB sintered magnets. Methodology of the study; Results and discussion.

Presents information on a study which calculated the influence of different grain boundary phases on the reversal process of sintered neodymium-iron-boron magnets using finite element method. Structure of the high energy density magnets; Background on micromagnetism; Influence of intergranular phases on coercivity.

Presents information on a study which investigated the effect of oxygen partial pressure during sintering process on the electromagnetic properties of Manganese-Zinc (Mn-Zn) ferrites. Description of Mn-Zn ferrites; Weight change during sintering process; Comparison on the effects of oxidation degree on the microstructure and on the electromagnetic properties.

Presents information on a study on the effect of Molybdenum oxide (MoO...) addition on the sintering behaviors and the magnetic properties of Nickel-Copper-Zinc ferrite for multilayer chip inductor. How the multilayer chip inductor is produced; Methodology; Results and conclusion.