Novel approaches to produce Al2O3–TiC/TiCN–Fe composite powders directly from ilmenite

AbstractAl2O3–TiC/TiCN–Fe composite powders were successfully prepared directly from ilmenite at 1300–1400°C. The effects of Al/C ratio, sintering atmosphere, and reaction temperature and time on the reaction products were investigated. Results showed that the nitrogen atmosphere was beneficial to the reduction of ilmenite and the formation of Al2O3–TiC/TiCN–Fe composite powders. When the reaction temperature was between 600 and 1100°C, the intermediate products, TiO2, Ti3O5 and Ti4O7 were found, which changed to TiC or TiCN at higher temperature. Al/C ratio was found to affect the reaction process and synthesis products. When Al addition was 0.5mol, the Al2O3 phase did not appear. The content of carbon in TiCN rose when the reaction temperature was increased

Quantitative prediction of structural fractures in the Paleocene lower Wenchang formation reservoir of the Lufeng Depression

Currently, the lower Paleogene Wenchang formation in the Lufeng Depression is the primary focus of reservoir development. The structural fractures that have formed inside of it not only serve as the principal path for oil migration, but also as oil storage space. As a result, the distribution features of structural fractures are crucial for future petroleum exploration and development in the Lufeng Depression. At the same time, with the quantity of conventional reservoirs in the Lufeng Depression on the decline, it is critical to determine the fracture distribution criteria for deep unconventional reservoirs. In this work, the lower Paleogene Wenchang formation in the Lufeng Depression is used as the research stratum. Then, based on existing logging data for the research region, the distinct physical properties of different rock kinds are calculated. The simulation results of the paleotectonic stress field in the study area using the finite element numerical simulation software ANSYS show that the high-value areas of maximum principal stress are the high-value areas of the uplift belt and low uplift, and the areas with low maximum principal stress are the low-value areas of Lufeng 13 Sag and the gentle slope belt in the north of Lufeng middle-low uplift. The fracture density is quantitatively predicted after the stress field simulation, which shows good agreement between the anticipated and actual observed values, and an average error of 13.61%. The predicted findings may provide new ideas for future petroleum exploration.cited as: Li, H., Yu, F., Wang, M., Wang, Y., Liu, Y. Quantitative prediction of structural fractures in the Paleocene lower Wenchang formation reservoir of the Lufeng Depression. Advances in Geo-Energy Research, 2022, 6(5): 375-387. https://doi.org/10.46690/ager.2022.05.0

Optimization of Combined Casing Treatment Structure Applied in a Transonic Axial Compressor Based on Surrogate Model

For modern high load compressors, an excellent stability-enhancing capability by casing treatment (CT) is desirable. However, it is very time consuming to accomplish effective CT design. In this study, a new combined CT structure composed of axial skewed slots and end-wall injection, was proposed to be installed in transonic axial compressors to improve the overall performance. Considering the high computation cost for CFD simulation of the flow field in transonic compressor, a Gaussian Process Regression (GPR) surrogate model combined with Latin hypercube sampling, was utilized to predict compressor performance. For optimization process, a multi-objective evolutionary algorithm (NSGA-Ⅱ) was adopted to obtain the Pareto-optimal front. The main geometric parameters of the slot and the mass-flow rate of injection were selected as design parameters, with the peak efficiency and pressure ratio being two objectives. The results indicated that the surrogate model works well in capturing the key features of the concerning target and accelerating the optimization process. The optimal scheme of the combined CT was found able to increase stall margin (SM) by 19.5% with low efficiency penalty, showing a better performance than the reference combined casing treatment (CCT) scheme. What’s more, the analysis results of entropy generation showed that the superior effect of optimized scheme (OPT) can be attributed to the improvement of exchange flow in slots and the decreased loss in the whole passage

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Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88118/1/24749_ftp.pd

Robot Motion Planning Method Based on Incremental High-Dimensional Mixture Probabilistic Model

The sampling-based motion planner is the mainstream method to solve the motion planning problem in high-dimensional space. In the process of exploring robot configuration space, this type of algorithm needs to perform collision query on a large number of samples, which greatly limits their planning efficiency. Therefore, this paper uses machine learning methods to establish a probabilistic model of the obstacle region in configuration space by learning a large number of labeled samples. Based on this, the high-dimensional samples' rapid collision query is realized. The influence of number of Gaussian components on the fitting accuracy is analyzed in detail, and a self-adaptive model training method based on Greedy expectation-maximization (EM) algorithm is proposed. At the same time, this method has the capability of online updating and can eliminate model fitting errors due to environmental changes. Finally, the model is combined with a variety of sampling-based motion planners and is validated in multiple sets of simulations and real world experiments. The results show that, compared with traditional methods, the proposed method has significantly improved the planning efficiency

Recruitment mechanisms and therapeutic implications of tumor-associated macrophages in the glioma microenvironment

As one of the main components of the glioma immune microenvironment, glioma-associated macrophages (GAMs) have increasingly drawn research interest. Primarily comprised of resident microglias and peripherally derived mononuclear macrophages, GAMs are influential in a variety of activities such as tumor cell resistance to chemotherapy and radiotherapy as well as facilitation of glioma pathogenesis. In addition to in-depth research of GAM polarization, study of mechanisms relevant in tumor microenvironment recruitment has gradually increased. Suppression of GAMs at their source is likely to produce superior therapeutic outcomes. Here, we summarize the origin and recruitment mechanism of GAMs, as well as the therapeutic implications of GAM inhibition, to facilitate future glioma-related research and formulation of more effective treatment strategies

Neuroprotective effects of etanercept on diabetic retinopathy via regulation of the TNF-α/NF-κB signaling pathway

Purpose: To study the influence of etanercept on diabetic retinopathy in rats via tumor necrosis factor alpha (TNF-α)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. Methods: Thirty-six Sprague-Dawley (SD) rats were randomly divided into normal, model and etanercept groups. The expression of Caspase-3 was determined by immunohistochemistry, while the relative protein and mRNA expression levels of TNF-α and NF-κB were determined by Western blotting and quantitative polymerase chain reaction, respectively. Besides, the contents of TNF-α and interleukin-1 beta (IL-1β) were evaluated using enzyme-linked immunosorbent assay (ELISA), while cell apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Results: Immunohistochemical studies showed that the mean optical density of tissues positive for caspase-3 in both the model and etanercept groups were significantly higher than in the normal group (p < 0.05), while the mean optical density in the etanercept group was significantly lower than that in the model group (p < 0.05). The protein expression levels of TNF-α and NF-κB in the etanercept group were significantly lower than those in the model group (p < 0.05). Furthermore, mRNA expressions of TNF-α and NF-κB declined in the etanercept group (p < 0.05); in addition, TNF-α, and IL-1β levels in the etanercept group were lower than in the model group (p < 0.05). Cell apoptosis in the etanercept group was also lower than in the model group. Conclusion: Etanercept suppresses TNF-α/NF-κB signaling pathway thereby repressing inflammation and cell apoptosis in diabetic retinopathy rats. Therefore, etenercept’s neuroprotective effect may potentially be useful in developing a suitable therapy for diabetic neuropathy

Corak Pemikiran Dan Gerakan Aktivis Perempuan (Melacak Pandangan Keagamaan Aisyiyah Periode 1917–1945)

This paper discusses the patterns of religious thought of the women activistsin the early period of Aisyiyah. The women activists are Siti Walidah, Siti Bariyah, SitiAisyah, Siti Badilah, Siti Munjiyah, Siti Badilah, Siti Hayyinah, dan Siti Umniyah.Through ahistorical approach, the author founds a link between colonialism that occurin Muslim countries and the revival of the spirit of women activists in mobilizing theMuslims society. The author also asserts that the thought of Aisyiyah leaders includingin the Islamic modernism that mean are Islamists a progresive religion, Islam is areligion of liberation, enlighten and advance. This understanding is very influential inthe development of Aisyiyah recently. The formers of Aisyiyah aware of the importanceof women\u27s participation and role in Islamic Da\u27wah join with men to accelerate therealization of a prosperous society.Key words: Thought, women activists, AisyiyahMakalah ini membahas tentang corak pemikiran keagamaan perempuan aktivisgerakan Aisyiyah pada periode awal. Mereka adalah Siti Walidah, Siti Bariyah, SitiAisyah, Siti Badilah, Siti Munjiyah, Siti Badilah, Siti Hayyinah, dan Siti Umniyah.Melalui pendekatan historis, penulis menemukan kaitan antara gelombang kolonialismeyang terjadi di negara-negara muslim dengan semangat kebangkitan kaum perempuandalam menggerakkan kaum muslim khususnya kaum perempuan. Penulis jugamenegaskan bahwa pemikiran para tokoh Aisyiyah termasuk paham modernisme Islamyaitu Islam sebagai agama yang berkemajuan, agama dengan ajaran yang membebaskan,mencerahkan dan memajukan. Pemahaman ini sangat berpengaruh dalamperkembangan dakwah ‘Aisyiyah ke depan. Para tokoh Aisyiyah menyadari akanpentingnya perempuan berpartisipasi dan berperan dalam Dakwah Islam bersamasamadengan laki-laki untuk mempercepat terwujudnya masyarakat sejahtera

Hepatotoxicity induced by zoledronic acid in an aged woman with primary osteoporosis

Zoledronic acid, a bisphosphonate, has been approved for treatment and prevention of osteoporosis. This case describes a 73-year-old woman with primary osteoporosis who developed transient hepatotoxicity after zoledronic acid (ZOL) treatment. Three days after ZOL infusion, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) were increased by 9.9, 8.1, and 3.7 times, respectively, compared with pretreatment values. Liver protective agents were administered. The aminotransferase returned within normal ranges 12 days post-infusion. Currently, the relationship of ZOL and liver damage is not quite clear, which cannot be explained by its pharmacokinetics. The aim of this case report is to increase the clinician’s awareness of the possible adverse effect on the liver, and ZOL should be cautiously administered in patients with liver disease