Search

[Introduction] With the continuous increase of offshore wind farms, conflicts in the use of marine areas has become increasingly severe. The integrated development of offshore wind power and aquaculture has attracted growing attention, with various structural designs for wind turbine foundations integrated with aquaculture cages being proposed. However, most of these designs are still in the conceptual stage and far from practical engineering applications. [Method] Based on the requirements of equal netting mass, equal biomass of marine growth attached to the netting, and equivalent hydrodynamic performance of the netting, the paper introduced an efficient method to calculate the equivalent loads of the cages. Considering the design loads of a 14 MW wind turbine and marine hydrological conditions, a jacket foundation structure suitable for the 14 MW offshore wind turbines was designed, integrating internal and external aquaculture cages to propose two integrated systems combining jacket foundations and marine aquaculture cages. Using the Morison model and considering the impact of nonlinear waves, static analyses of different designs were conducted in SACS based on the proposed equivalent modeling method for the cages. [Result] The study shows that the integration of internal and external cages with the jacket foundation has little to negligible impact on the first and second order frequencies of the overall system and a more significant effect on the third order frequency. The rotation condition is the controlling case, and after adding internal and external aquaculture cages, local reinforcement of the jacket foundation is required. Computational results for the integrated designs of the 14 MW offshore wind turbine jacket foundation with internal or external cages meet the regulatory design requirements. [Conclusion] The analysis results provide a reference for the engineering application of the integrated system design of offshore wind turbine foundations and marine aquaculture cage systems.

BackgroundOsteonecrosis of the femoral head (ONFH) is a severe complication of systemic lupus erythematosus (SLE) and occurs more frequently in SLE patients than in other autoimmune diseases, which can influence patients’ life quality. The objective of this research was to analyze risk factors for the occurrence of ONFH in female SLE patients, construct and validate a risk nomogram model.MethodsClinical records of SLE patients who fulfilled the 1997 American College of Rheumatology SLE classification criteria were retrospectively analyzed. The Least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression analysis were used to summarize the independent risk factors of ONFH in female SLE patients, which were used to develop a nomogram. The predictive performance of the nomogram was assessed using the receiver characteristic (ROC) curve, calibration curves and decision curve analysis (DCA).Results793 female SLE patients were ultimately included in this study, of which 87 patients (10.9%) developed ONFH. Ten independent risk factors including disease duration, respiratory involvement, menstrual abnormalities, Sjögren's syndrome, osteoporosis, anti-RNP, mycophenolate mofetil, cyclophosphamide, biologics, and the largest daily glucocorticoid (GC) were identified to construct the nomogram. The area under the ROC curve of the nomogram model was 0.826 (95% CI: 0.780–0.872) and its calibration for forecasting the occurrence of ONFH was good (χ2= 5.589, P = 0.693). DCA showed that the use of nomogram prediction model had certain application in clinical practice when the threshold was 0.05 to 0.95. In subgroup analysis, we found that the risk of ONFH was significantly increased in age at SLE onset of ≤ 50 years old, largest daily GC dose of ≥50 mg and the therapy of GC combined with immunosuppressant patients with menstrual abnormalities.ConclusionMenstrual abnormalities were the first time reported for the risk factors of ONFH in female SLE patients, which remind that clinicians should pay more attention on female SLE patients with menstrual abnormalities and take early interventions to prevent or slow the progression of ONFH. Besides, the nomogram prediction model could provide an insightful and applicable tool for physicians to predict the risk of ONFH.

The innovative aquaculture equipment known as high-density polyethylene (HDPE) floating rafts has gained popularity among fishermen in the southeast coastal regions of China. Compared to deep-water anti-wave fish cages, the construction costs of HDPE floating rafts are 50% to 75% less. There is a dearth of comprehensive publicly available records of HDPE floating rafts sea trial data, despite substantial numerical studies on the motion response of aquaculture fish cages and scale model experiments under controlled-wave conditions. This study involves sea trial techniques under operational and extreme environmental conditions for motion responses of HDPE floating rafts, presents a comprehensive procedure for sea trials of HDPE floating rafts, summarizes the issues encountered during the trials, and suggests solutions. Using MATLAB for independent programming, motion videos and photos collected from the sea trials are processed for image capture, yielding the original time history curve of vertical displacement. Based on the sea trials’ data, including motion displacement, acceleration, mooring line force, overall deformation patterns, and current and wave data, recommendations are provided for the design and layout of HDPE floating rafts. Based on the Fast Fourier Transform (FFT) method for spectral analysis, the influence of interference items on the observational data is eliminated; the rationality of the observational data is verified in conjunction with the results of the Gabor Transform. This study offers a scientific analytical method for the structural design and safe operation of HDPE floating rafts and provides a reference for subsequent numerical simulations.

Abstract This paper aims at preparing a smart wearable purple ceramic that meet the color requirements of purple smart wear in the market after using zirconate neodymium as a chromogenic agent. However, the mechanical performance of zirconate neodymium purple ceramic is not satisfactory, especially it has an extremely low fracture toughness. To solve this, a 3 mol% yttria-stabilized zirconia (3YSZ) is added to zirconate neodymium in the preparation of multiphase ceramics to improve its mechanical properties. In this experiment, a series of ceramic samples with addition of increasing amount of 3YSZ 0, 20, 40, 50, 60, 70 and 80% were prepared in the 1400–1500 °C sintering temperature range. It was found that at the same temperature, the mechanical properties of the ceramic samples gradually improved with the increase in the 3YSZ content. Moreover, with the same content, the mechanical properties of the ceramic samples gradually improved with the decrease in temperature. The results show that when 3YSZ has a mass fraction of 80% and is sintered at 1400 °C, the fracture toughness of the prepared ceramic samples reaches 8.15 MPa‧m1/2, which is nearly two times higher than that of the monolithic neodymium zirconate 2.57 MPa‧m1/2. The Vickers hardness of the prepared ceramic samples reached 12.93 GPa, which is nearly 88% higher than the undoped neodymium zirconate. This indicates that the samples can be applied in smart wearables, such as mobile phone backplane, with a certain practical significance for engineering toughening of zirconate ceramics.

In this paper a finite difference method (FDM) is provided for pricing perpetual timer options under the Heston volatility model. Considering the degeneracy of the pricing equation, we first prove the existence and uniqueness of the solution of the pricing problem with a new notion of boundary conditions at degenerate boundary and the infinity. Then we discuss the choice of artificial boundary value conditions and obtain a prior estimate of the internal error caused by the boundary value error. This estimate helps to choose appropriate artificial boundary values and solution domain to reduce internal error of the numerical solution. Furthermore, We build a FDM with second-order convergence for the pricing problem. Finally, we implement our method and show the visualization results.

To address problems encountered in current potato harvesting machines, such as potato damage, poor adaptability, and low operational efficiency, a new towed potato picking and bagging machine (4UJ-180A) equipped with a soil-digging axis, flexible conveying device, and hydraulic control system was developed. The digging mechanism of the harvester can reduce soil blockage and minimize damage to potato skins. The rubber biomimetic finger can maintain stable transportation of potatoes and minimize collisions. The hydraulic control system, the buffering components, and the bagging device work together to flexibly and continuously collect potatoes, reducing skin damage during the harvesting process. Based on the structure of the whole machine, the harvesting process, and the working principle, the soil picking, lifting buffer, and potato collection process were analyzed. Theoretical calculations were used to determine the structure and operational parameters of the potato picking, lifting buffering, and bagging segments. An experiment utilizing the orthogonal method was conducted. The experiment consisted of three factors and three levels, with the test indicators being the potato skin damage rate, potato injury rate, loss rate, and impurity rate. The factors considered in the experiment were the forward speed, conveyor speed, and soil-digging shaft speed. Field experiments demonstrate that at a forward speed of 1 m/s, soil digging shaft speed of 35 rpm, and conveyor speed of 28 rpm, the rate of potato skin damage is 2.8%, the potato injury rate is 1.3%, the loss rate is 0.4%, and the impurity rate is 0.7%. These experiments verify that all indicators adhere to national industry standards, providing a valuable reference for equipment research, development, optimization, and improvement.

Highlights 1. Low expression of miRNA-214-5p is observed in prostate cancer cells. 2. miRNA-214-5p inhibits the proliferation of prostate cancer cells in vitro by targeting SOX4.

To address the problems of low pickup rates and high rates of wounds in the mechanised harvesting of potatoes under sectional harvesting conditions, a spring-finger potato picker was designed and its overall structure and working principles were described. The kinematic principle of the spring-finger was analysed based on the picking constraints, and the kinematic parameters of the picker were determined. A response surface Box–Behnken Design test design was used to carry out a quadratic orthogonal rotational test, with the speed of the spring-finger, the forward speed of the machine, and the embedded depth as test factors, and the loss rate and the wounded potato rate as evaluation indicators. The test results were optimised and analysed. When the spring-finger speed was 19.57 r/min, the forward speed was 0.61 m/s and the embedded depth was 71.31 mm, the loss rate was 1.18%, and the wounded potato rate was 5.71%. The optimised data were verified, and the results showed that the loss rate of the spring-finger potato picker was 1.48% and the wounded potato rate was 4.98%, meeting the potato picking and harvesting requirements. The research can provide a theoretical basis and design reference for the development and application of sectional potato harvesting machinery.

In this paper we consider fully nonlinear elliptic equations, including the Monge-Ampere equation and the Weingarden equation. We assume that $F(D^2u, x) = f(x) quad x in Omega,,$ $u(x) = g(x) quad xin partial Omega $ has a solution $u$ in $C^2(Omega) cap C(ar {Omega} )$, and $F(D^2v(x), x) = f(x) quad xin Omegasetminus S,,$ $v(x)= g(x)quad xin partial Omega $ has a solution $v$ in $C^2(Omegasetminus S ) cap mbox{Lip}(Omega) cap C(ar {Omega})$. We prove that under certain conditions on $S$ and $v$, the singular set $S$ is removable; i.e., $u=v$.

Copyright of INMATEH - Agricultural Engineering is the property of INMATEH - Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)