553 research outputs found

    Systematic study on propulsive performance of tandem hydrofoils for a wave glider

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    This paper presents the propulsive performance optimization of tandem hydrofoils equipped in a wave glider in head sea conditions with the aid of computational fluid dynamic (CFD) method by using a commercial CFD code, STAR-CCM+. Firstly, this work performs a systematic study on a single 2D hydrofoil to study the effect of varying the pivot position and the torsional spring stiffness to seek for the optimum propulsive performance within a range of velocity. Secondly, parametric studies on the propulsive performance of 2D and 3D six tandem hydrofoils are conducted by varying the oscillation amplitude and the torsional spring stiffness. The result reports: The results show that the torsional springs play a critical role in propulsive performance, comparing to the pivot position. The propulsive performance of the middle hydrofoil is greater than the others in the fore and after positions. When 2D and 3D six tandem hydrofoils achieve the optimum propulsive performance, the frequency ratio is chosen to be around 25 (torsional spring stiffness (k S =0.8N⋅m/rad)) and 17 (torsional spring stiffness (k S =11.8N⋅m/rad)), respectively. Comparing to previous study, the propulsive performance of each hydrofoil in six tandem hydrofoil configuration is greatly improved and none of hydrofoil produce negative thrust

    Impact of New Quality Productive Forces on the High-Quality Development of the Construction Industry: Evidence from China

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    Introduction. Recognised as an emerging and advanced mode of productivity, new quality productive forces (NQPF) have significantly contributed to the development of various industries. Investigating their influence on the high-quality development of the construction industry (HDCI) can offer theoretical support and practical guidance for the transformation and upgrading of the industry. This includes improving quality and efficiency, advancing green development, and promoting sustainable practices. Such efforts are of great significance for the high-quality development of the national economy. Aim and tasks. This study aims to develop an index system for assessing the impact of new quality productive forces on the high-quality development of the construction industry, and empirically examines their relationship within the context of industrial structure modernisation. Results. The regression coefficient of NQPF on HDCI was 0.293, and all regression results remained positive after the sequential inclusion of the control variables. The regression coefficient of NQPF on industrial structure upgrading was 0.056, whereas the regression coefficients of NQPF and industrial structure upgrading on HDCI were 0.201 and 0.256, respectively. A bootstrap test involving 1,000 resampling iterations was performed, and the resulting confidence interval was [0.0005, 0.0406], which does not include zero. The results of the regional heterogeneity analysis indicate that the positive effect of NQPF on HDCI was strongest in the eastern region (0.348), followed by the western region (0.132), with the impact on the central region being statistically insignificant. After applying the robustness checks, all regression results remained positive and statistically significant at the 1% level. Conclusions. This study develops a framework for analysing the impact of NQPF on HDCI and provides recommendations for the forthcoming construction industry and related policy research. Under the NQPF policy framework, the impetus to promote high-quality development of China’s economy and construction industry is reasonably policy-driven, featuring industrial upgrading and regional optimisation in synergy with technological popularisation. Policy choices under the NQPF regarding China’s construction industry and the high-quality development of its economy are of critical importance. Moreover, they further contribute to the promotion and enhancement of environmental sustainability

    Responses of calcareous sand foundations to variations of groundwater table and applied loads

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    The long-term settlement of calcareous sand foundations caused by daily periodic fluctuations has become a significant geological hazard, but effective monitoring tools to capture the deformation profiles are still rarely reported. In this study, a laboratory model test and an in situ monitoring test were conducted. An optical frequency domain reflectometer (OFDR) with high spatial resolution (1 mm) and high accuracy (±10-6) was used to record the soil strain responses to groundwater table and varied loads. The results indicated that the fiber-optic measurements can accurately locate the swelling and compressive zones. During the loading process, the interlock between calcareous sand particles was detected, which increased the internal friction angle of soil. The foundation deformation above the sliding surface was dominated by compression, and the soil was continuously compressed beneath the sliding surface. After 26–48 h, calcareous sand swelling occurred gradually above the water table, which was primarily dependent on capillary water. The swelling of the soil beneath the groundwater table was completed rapidly within less than 2 h. When the groundwater table and load remain constant, the compression creep behavior can be described by the Yasong-Wang model with R2 = 0.993. The daily periodically varying in situ deformation of calcareous sand primarily occurs between the highest and lowest groundwater tables, i.e. 4.2–6.2 m deep. The tuff interlayers with poor water absorption capacity do not swell or compress, but they produce compressive strain under the influence of deformed calcareous sand layers

    Ability of Genomic Prediction to Bi-Parent-Derived Breeding Population Using Public Data for Soybean Oil and Protein Content

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    Genomic selection (GS) is a marker-based selection method used to improve the genetic gain of quantitative traits in plant breeding. A large number of breeding datasets are available in the soybean database, and the application of these public datasets in GS will improve breeding efficiency and reduce time and cost. However, the most important problem to be solved is how to improve the ability of across-population prediction. The objectives of this study were to perform genomic prediction (GP) and estimate the prediction ability (PA) for seed oil and protein contents in soybean using available public datasets to predict breeding populations in current, ongoing breeding programs. In this study, six public datasets of USDA GRIN soybean germplasm accessions with available phenotypic data of seed oil and protein contents from different experimental populations and their genotypic data of single-nucleotide polymorphisms (SNPs) were used to perform GP and to predict a bi-parent-derived breeding population in our experiment. The average PA was 0.55 and 0.50 for seed oil and protein contents within the bi-parents population according to the within-population prediction; and 0.45 for oil and 0.39 for protein content when the six USDA populations were combined and employed as training sets to predict the bi-parent-derived population. The results showed that four USDA-cultivated populations can be used as a training set individually or combined to predict oil and protein contents in GS when using 800 or more USDA germplasm accessions as a training set. The smaller the genetic distance between training population and testing population, the higher the PA. The PA increased as the population size increased. In across-population prediction, no significant difference was observed in PA for oil and protein content among different models. The PA increased as the SNP number increased until a marker set consisted of 10,000 SNPs. This study provides reasonable suggestions and methods for breeders to utilize public datasets for GS. It will aid breeders in developing GS-assisted breeding strategies to develop elite soybean cultivars with high oil and protein contents

    Numerical investigation of a wave glider in head seas

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    A wave glider comprises a surface boat, which harvests energy from wave and solar power, a submerged glider containing six pairs of tandem hydrofoils and a tether connecting them in between. This paper presents a numerical simulation to predict the wave glider dynamic performance in head seas with the aid of computational fluid dynamic (CFD) method. The simulation involves two commercial CFD software packages, FINE/Marine and STAR-CCM+. Firstly, unsteady Reynolds Averaged Navier-Stokes (URANS) simulation was built in FINE/Marine with volume of fluid (VOF) model to simulate the flow around the surface boat and the tandem hydrofoils as a system, followed by the high-fidelity simulation of the passive eccentric rotation of the underwater tandem hydrofoils in STAR-CCM + using overset mesh. By taking the advantages of both softwares, manual iteration was conducted to achieve a converged result. Consequently, by analyzing these results, the surge force acting on the surface boat and the passive eccentric rotation law of the hydrofoils have been achieved which are proved to be the main factors affecting the propulsion efficiency of the wave glider

    Psychopathy and Decision-Making: Antisocial Factor Associated With Risky Decision-Making in Offenders

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    Psychopathy is a personality development disorder increasing the risk of antisocial behavior. Studies on the relationship between psychopathy and decision-making have received limited attention and the result of studies is mixed. A present study examines whether or not the different factors of psychopathy are related to decision-making under risk and ambiguity in offenders and how they are related. Also, the study investigates whether general intelligence is associated with decision-making or moderates the relationship between psychopathy and decision-making. The results showed that only antisocial factor of psychopathy significantly correlates with Game of Dice Task (GDT) risky selections, but there no general relation between psychopathy and Iowa Gambling Task (IGT) performance. Lastly, general intelligence neither is related to decision-making under risk and ambiguity nor moderates the relationship between decision-making and psychopathy. The study results show that antisocial factor of psychopathy was associated with decision-making under risk rather than ambiguity. Our results also suggest that the antisocial factor of psychopathy was more related to executive dysfunction in offenders

    Bevacizumab-induced immune thrombocytopenia in an ovarian cancer patient with mixed connective tissue disease: case report and literature review

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    Drug-induced immune thrombocytopenia is an adverse reaction marked by accelerated destruction of blood platelets. In cancer therapy, thrombocytopenia has many other causes including bone marrow suppression induced by chemotherapeutic agents, infection, and progression of cancer; drug-induced thrombocytopenia can easily be misdiagnosed or overlooked. Here, we present a case of an ovarian cancer patient with a history of mixed connective tissue disease who underwent surgery followed by treatment with paclitaxel, cisplatin, and bevacizumab. The patient developed acute isolated thrombocytopenia after the sixth cycle. Serum antiplatelet antibody testing revealed antibodies against glycoprotein IIb. After we analyzed the whole therapeutic process of this patient, drug-induced immune thrombocytopenia was assumed, and bevacizumab was conjectured as the most probable drug. Thrombocytopenia was ultimately successfully managed using recombinant human thrombopoietin, prednisone, and recombinant human interleukin-11. We provide a summary of existing literature on immune thrombocytopenia induced by bevacizumab and discuss related mechanisms and triggers for drug-induced immune thrombocytopenia. The present case underscores the potential of bevacizumab to induce immune-mediated thrombocytopenia, emphasizing the need for heightened vigilance towards autoimmune diseases or an autoimmune-activated state as plausible triggers for rare drug-induced immune thrombocytopenia in cancer therapy

    Percutaneous cryoablation of subcapsular hepatocellular carcinoma: a retrospective study of 57 cases

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    PURPOSEThis study aims to evaluate the safety and effectiveness of the percutaneous cryoablation for subcapsular hepatocellular carcinoma (HCC).METHODSA total of 57 patients with subcapsular (<1 cm form the liver edge) HCCs (68 lesions), who were treated with CT-guided percutaneous cryoablation in the Department of Interventional Radiology of our hospital between July 1, 2016 and September 1, 2018, were retrospectively included. Complete ablation rate, local tumor progression (LTP) and treatment-related complications were evaluated. Furthermore, the degree of intraoperative and postoperative pain was measured with the visual analog scale (VAS), and laboratory findings were compared before and after the procedure.RESULTSAll patients successfully completed the treatment. The mean follow-up period was 12.8 months (range, 3–27 months), and the complete ablation rate was 97% (66/68). Local tumor progression occurred in 11 lesions (16.2%), and the 6-, 12- and 18-month cumulative LTP rates were 4.0%, 8.2% and 20.5%, respectively. Two patients (3.5%, 2/57) developed major complications, and 12 patients had minor complications (22.8%, 12/57). The mean VAS score during the operation was 1.65 points (range, 1–3 points). Postoperative pain worsened in 3 patients, and the VAS scores reached 4–5. Transient changes in biochemical and hematologic markers were observed.CONCLUSIONPercutaneous cryoablation for subcapsular HCC is safe and effective, the procedure is simple and the patients suffer less pain

    Heparan Sulfate Facilitates Spike Protein-Mediated SARS-CoV-2 Host Cell Invasion and Contributes to Increased Infection of SARS-CoV-2 G614 Mutant and in Lung Cancer

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    The severe acute respiratory syndrome (SARS)-like coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has been a serious threat to global public health with limited treatment. Cellular heparan sulfate (HS) has been found to bind SARS-CoV-2 spike protein (SV2-S) and co-operate with cell surface receptor angiotensin-converting enzyme 2 (ACE2) to mediate SARS-CoV-2 infection of host cells. In this study, we determined that host cell surface SV2-S binding depends on and correlates with host cell surface HS expression. This binding is required for SARS-Cov-2 virus to infect host cells and can be blocked by heparin lyase, HS antagonist surfen, heparin, and heparin derivatives. The binding of heparin/HS to SV2-S is mainly determined by its overall sulfation with potential, minor contribution of specific SV2-S binding motifs. The higher binding affinity of SV2-S G614 mutant to heparin and upregulated HS expression may be one of the mechanisms underlying the higher infectivity of the SARS-CoV-2 G614 variant and the high vulnerability of lung cancer patients to SARS-CoV-2 infection, respectively. The higher host cell infection by SARS-CoV-2 G614 variant pseudovirus and the increased infection caused by upregulated HS expression both can be effectively blocked by heparin lyase and heparin, and possibly surfen and heparin derivatives too. Our findings support blocking HS-SV2-S interaction may provide one addition to achieve effective prevention and/treatment of COVID-19

    In vitro bioaccessibility and physicochemical properties of phytosterol linoleic ester synthesized from soybean sterol and linoleic acid

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    Phytosterols are bioactive components capable of reducing cholesterol level in serum and reducing risk of arteriosclerosis. In this study, conditions for the synthesis of maximum yield of phytosterol linoleic ester (PLE) was optimized and the physicochemical properties and in vitro bioaccessibility of the PLE were assessed. Under the optimized condition of 1:1.1 mol ratio of phytosterol and linoleoyl chloride at 80 °C for 1.5 h, the conversion rate of phytosterol reached 96.1%. Its solubility in oil increased 20 times, up to 33.8%. Also, peroxide value of PLE was much lower than linoleic acid (32.9 and 47.0 mmol/kg), which means better oxidative stability. Bioaccessibility of PLE was affected by time, concentration of bile extract, and dissolved medium. It was 4.93% alone, increased by 2.5 times compare to phytosterol; or 53.46% in oil, under the condition of 40 mg/mL bile extract for 120 min. In conclusion, under the tested condition, phytosterol conversion rate, its solubility in oil and bioaccessibility were improved significantly. The method showed great potential in manufacture high quality and quantity of PLE
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