Preparation of Nickel-Based Nanolubricants and Investigation of their Tribological Behavior

In situ surface-modification technique is adopted in present research to fabricate a series of Ni nanoparticles as well as Cu@Ni nanoparticles with different size and morphology. The correlation among the composition, structure, size, and morphology and tribological properties of as-synthesized additives were explored, and the friction-reducing, antiwear, and worn surface self-healing mechanisms of the additives were discussed. It was found that Ni nanoparticles with a smaller size show higher surface activity and can readily deposit on the sliding surface and form a stable and continuous protective layer thereon. Compared with sphere-like and triangular rod-like Ni nanoparticles, triangular plate-like Ni nanoparticles are more liable to form protective layer. Compared to Ni-based nanolubricants, as-synthesized Cu@Ni nanolubricants exhibit better friction-reducing, antiwear, and extreme pressure properties. It is because the highly active Ni nanocores and O- and N-containing organic modifying agents can readily form boundary lubricating film on sliding steel surfaces, while Cu nanocores can easily deposit on sliding steel surface to form a protective layer (self-healing film) thereon. Ni nanoparticles as nanoadditives in solid-liquid lubricating system significantly reduce the friction in all lubrication regimes: As a nanolubricant, Ni nanoparticles exhibit popular and effective friction-reducing, antiwear, and extreme pressure properties

Application of Dynamic Centrifugal Compressor Model for Mechanical Vapor Recompression System Simulation

In order to reducing energy costs and CO2 foot-print, mechanical vapor recompression system (MVR) is used for thermal separation processes such as evaporation and distillation are energy intensive instead of multiple-effect evaporation system. For medium and high capacities, centrifugal compressor (fan) is the most commonly used type for gas compression with a limited operational range and control of the compressors is crucial for safe and efficient operation. The model based on first principles is developed for dynamic performance, which is determined from the compressor geometry and not from the experimentally determined characteristic performance curves. Impeller losses are studied: incidence, skin friction, choking, jet-wake mixing, blade loading, hub to shroud, tip clearance, shock and distortion losses. The vaneless diffuser outlet is calculated using a one-dimensional numerical solution to the underlying differential equations. Dynamic model of a centrifugal compressor capable of system simulation computational environment is presented. A model has been created for simulation of a separation and gas compression system. Based on the theory for centrifugal compressors and control theory a control strategy has been applied to the model based on the available equipment. The model has been used to investigate how the gas compression system responds to changes in the compressor inlet flows and conditions. The model has been used to investigate the performance of the gas compression system at off-design conditions. The surge line for the compressor can also be determined from the simulation results. Furthermore, the model presented here provides a valuable tool for evaluating the system performance as a function of various operating parameters

One-stage partial vertebrectomy, titanium mesh implantation and pedicle screw fixation in the treatment of thoracolumbar burst fractures through a posterior approach

OBJECTIVE: To analyze the clinical results of a partial vertebrectomy with titanium mesh implantation and pedicle screw fixation using a posterior approach to reconstruct the spine in the treatment of thoracolumbar burst fractures. METHOD: From January 2006 to August 2008, 20 patients with severe thoracolumbar fractures were treated.For vertebral bodies associated with one injured intervertebral disk, subtotal vertebrectomy surgery and single-segment fusion were performed. For vertebral bodies with two injured adjacent intervertebral disks, partial vertebrectomy surgery and two-segment fusion were performed. RESULTS: All 20 patients were followed up for 12 to 24 months (average of 18 months). There were no complications such as wound infections, hemopneumothorax or abdominal infections in any of the patients. The neurological status of all of the patients was improved by at least one American Spinal Injury Association grade by the last follow-up. The anterior vertebral body height was an average of 50.77% before surgery, 88.51% after surgery and 87.86% at the last follow up; the sagittal Cobb angle was improved, on average, from 26.15° to 5.39° and was 5.90° at the last follow up. The percentage of spinal stenosis was improved, on average, from 26.07% to 4.93%° and was 6.15% at the last follow up. There were significant differences in the anterior vertebral body height pre- and post-surgery and in the sagittal Cobb angle and the percentage of spinal stenosis (

Direction Finding in Partly Calibrated Arrays Exploiting the Whole Array Aperture

We consider the problem of direction finding using partly calibrated arrays, a distributed subarray with position errors between subarrays. The key challenge is to enhance angular resolution in the presence of position errors. To achieve this goal, existing algorithms, such as subspace separation and sparse recovery, have to rely on multiple snapshots, which increases the burden of data transmission and the processing delay. Therefore, we aim to enhance angular resolution using only a single snapshot. To this end, we exploit the orthogonality of the signals of partly calibrated arrays. Particularly, we transform the signal model into a special multiple-measurement model, show that there is approximate orthogonality between the source signals in this model, and then use blind source separation to exploit the orthogonality. Simulation and experiment results both verify that our proposed algorithm achieves high angular resolution as distributed arrays without position errors, inversely proportional to the whole array aperture

LncRNA MALAT1: A potential therapeutic target in DSSinduced ulcerative colitis progression in vitro

Purpose: Ulcerative colitis is a severe disease affecting human health worldwide. Studies have shown that lncRNA MALAT1 has a significant correlation with breast, pancreatic, colon and liver cancers, but its effects on colitis is yet to be discovered. In this study, the potential role of lncRNA MALAT1 and the underlying molecular mechanism in DSS-induced colitis were investigated in vitro.Methods: Colorectal mucosal cell line FHC was induced with dextran sulphate sodium (DSS) to form an in vitro colitis model. Transfection procedure was employed to up- or down-regulate the expressions of lncRNA MALAT1 or miR-30c-5p in FHC cells. Cell viabilities were detected by CCK-8 assay. RT-qPCR was applied for evaluating gene expressions in normal FHC and DSS-induced FHC cell lines, while protein expression levels of target genes were examined by Western blot analysis. Starbase was used to predict the molecular interaction between MALAT1 and miR-30c-5p, while luciferase reporter assay was utilized to verify the binding sites between the two genes.Results: Expression of MALAT1 in the DSS-induced FHC cells was high with low cell viabilities, compared to the normal FHC cells. In the DSS-induced colitis-like FHC cells, overexpression of MALAT1 inhibited cell viabilities, while its downregulation promoted it. MiR-30c-5p directly targets MALAT1 and inhibited its expression in DSS-treated FHC cells. Upregulation of miR-30c-5p increased cell viabilities. Bcl-xL expression was inhibited by the up-regulation of MALAT1, while that of Bax was enhanced and the mimics of miR-30c-5p reversed these observations, suggesting that the enhancement of apoptosis promoted by oe-MALAT1 could be inhibited by miR-30c-5p. The interaction between MALAT1 and miR-30c-5p regulated NF-κB/TGF-β/Wnt-β-catenin signaling pathway.Conclusion: Overexpression of MALAT1 led to inhibition of cell viability, while apoptosis and inflammation were promoted by targeting miR-30c-5p via NF-κB/TGF-β/Wnt-β-catenin signaling pathway. These findings suggest MALAT1 as a therapeutic target for treating colitis. Keywords: Colitis, MALAT1, miR-30c-5p, NF-κB/TGF-β/Wnt-β-catenin&nbsp

Enhanced cycling stability of Li–O2 batteries by using a polyurethane/SiO2/glass fiber nanocomposite separator

A considerable improvement in the cycle performance of aprotic Li–O2 batteries was achieved by using a polyurethane/SiO2 gel nanoparticles/glass fiber (PU/SiO2/GF) nanocomposite separator, where a persistent capability of 1000 mA h g−1 was maintained for at least 300 charge/discharge cycles in a DMSO electrolyte with 1 M LiClO4 and 0.05 M LiI. In comparison, the cell with a conventional GF separator in the same experimental setup only run for 60 cycles. SEM, XRD and FT-IR analyses indicate that the corrosion and dendritic growth of the Li anode were significantly inhibited during the charge/discharge cycling, and the eventual failure of the Li–O2 batteries was attributed to the cathode passivation caused by the accumulation of the discharge product, which blocked the transfer of oxygen and electrolyte to the MWNTs cathode

Modelling methane emissions and grain yields for a double-rice system in Southern China with DAYCENT and DNDC models

Acknowledgements This work contributed to the following projects: EU Horizon 2020 programme (SuperG) and The Scientific and Technological Innovation Special Fund Project of Carbon Peak and Carbon Neutrality in Jiangsu Province (No. BE2022311). The first author (Yang Guo) gratefully acknowledges financial support from China Scholarship Council (CSC).Peer reviewedPublisher PD

AFFIRM: Affinity Fusion-based Framework for Iteratively Random Motion correction of multi-slice fetal brain MRI

Multi-slice magnetic resonance images of the fetal brain are usually contaminated by severe and arbitrary fetal and maternal motion. Hence, stable and robust motion correction is necessary to reconstruct high-resolution 3D fetal brain volume for clinical diagnosis and quantitative analysis. However, the conventional registration-based correction has a limited capture range and is insufficient for detecting relatively large motions. Here, we present a novel Affinity Fusion-based Framework for Iteratively Random Motion (AFFIRM) correction of the multi-slice fetal brain MRI. It learns the sequential motion from multiple stacks of slices and integrates the features between 2D slices and reconstructed 3D volume using affinity fusion, which resembles the iterations between slice-to-volume registration and volumetric reconstruction in the regular pipeline. The method accurately estimates the motion regardless of brain orientations and outperforms other state-of-the-art learning-based methods on the simulated motion-corrupted data, with a 48.4% reduction of mean absolute error for rotation and 61.3% for displacement. We then incorporated AFFIRM into the multi-resolution slice-to-volume registration and tested it on the real-world fetal MRI scans at different gestation stages. The results indicated that adding AFFIRM to the conventional pipeline improved the success rate of fetal brain super-resolution reconstruction from 77.2% to 91.9%