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• Effects of vortex generator on subcooled flow boiling are investigated. • Vortex generator accelerates the bubble departure from the heating surface. • The maximum increase of the heat transfer coefficient by vortex generator is 8.4×103 W m-2 K-1. • A new correlation targeting vortex-enhanced subcooled flow boiling is developed. Subcooled flow boiling in a micro-channel is a mainstream heat dissipation way for high-heat-flux electronics. This paper presents a new idea to enhance heat transfer of subcooled flow boiling, i.e. accelerating bubble departure from the heating wall of flow channel by inserting a vortex generator; and the effects of vortex generator positions and working fluid conditions on the heat transfer characteristics are experimentally studied. The shape of the vortex generator is helix with the length, pitch, helix diameter and wire diameter of 22.5 mm, 1.8 mm, 1.8 mm and 0.2 mm, respectively. The vortex generator positions in the experiments include the front, the middle and the end of the flow channel; and the working fluid conditions include the mass fluxes of 1000 – 3500 kg m−2 s−1 and the inlet subcooling degrees of 30–50 K. It is found that the vortex generator could accelerate the bubble departure from the wall, and thus enhance the heat transfer in subcooled flow boiling. The maximum increase of the heat transfer coefficient of the all vortex channel is 8.4 × 103 W m−2 s−1, and the maximum increase rate of critical heat flux (CHF) is 21.8%. Furthermore, a new correlation to predict the heat transfer coefficients of vortex enhanced subcooled flow boiling was developed. The predictions by the new correlation could agree with 92% of the experimental data within a deviation of ± 30%, and the average deviation is 13.7%. [ABSTRACT FROM AUTHOR]

This study proposes a low-computational composite adaptive neural control scheme for the longitudinal dynamics of a swept-back wing aircraft subject to parameter uncertainties. To efficiently release the constraint often existing in conventional neural designs, whose closed-loop stability analysis always necessitates that neural networks (NNs) be confined in the active regions, a smooth switching function is presented to conquer this issue. By integrating minimal learning parameter (MLP) technique, prescribed performance control, and a kind of smooth switching strategy into back-stepping design, a new composite switching adaptive neural prescribed performance control scheme is proposed and a new type of adaptive laws is constructed for the altitude subsystem. Compared with previous neural control scheme for flight vehicle, the remarkable feature is that the proposed controller not only achieves the prescribed performance including transient and steady property but also addresses the constraint on NN. Two comparative simulations are presented to verify the effectiveness of the proposed controller. [ABSTRACT FROM AUTHOR]

Background: MMPs/TIMPs system is well known to play important roles in pressure overloadinduced cardiac remodeling, and Amlodipine and Atorvastatin have been showed to exert favourable protective effects on cardiovascular disease, however, it is not clear whether Amlodipine and Atorvastatin can improve hypertensive cardiac remodeling and whether the MMPs/TIMPs system is involved. The present study aims to answer these questions. Methods: 36 weeks old male spontaneous hypertension (SHR) rats were randomly divided into four groups: 1). SHR control group, 2). Amlodipine alone (10 mg/kg/d) group, 3). Atorvastatin alone (10 mg/kg/d) group, 4).Combination of Amlodipine and Atorvastatin (10 mg/kg/d for each) group. Same gender, weight and age of Wistar-Kyoto (WKY) rats with normal blood pressure were used as normal control. Drugs were administered by oral gavage over 12 weeks. The blood pressure and left ventricle mass index were measured. Enzyme activity of MMP-2 and MMP-9 was assessed with Gelatin zymography. MMP-2, MMP-9, TIMP-1 and TIMP-2 mRNA and protein expression was studied by RT-PCR and Western blot. Single factor ANOVA and LSD-t test were used in statistical analysis. Results: Treatment with Amlodipine alone or combination with atorvastatin significantly decreased blood pressure, left ventricle mass index in SHR rats (P < 0.05 for both). Compared with WKY rats, the myocardial levels of MMP-2, MMP-9 mRNA, protein and enzyme activity were significantly increased (P<0.05). Amlodipine alone, Atorvastatin alone, and combination of the two all reduced MMP-2 and MMP-9 mRNA, protein and enzyme activity, with the best effects seen in the combination. Compared with WKY rats, the myocardial levels of TIMP-1 mRNA and protein were significantly increased (P<0.05), however, there was no difference in levels of TIMP-2. Neither Amlodipine alone, Atorvastatin alone, nor combination of the two drugs significantly affect the expression of TIMP-1 or TIMP- 2. Conclusion: Amlodipine and Atorvastatin could improve ventricular remodeling in SHR rats through intervention with the imbalance of MMP-2/TIMP-2 and MMP-9/TIMP-1 system. [ABSTRACT FROM AUTHOR]

This paper presents an adaptive neural control for the longitudinal dynamics of a morphing aircraft. Based on the functional decomposition, it is reasonable to decompose the longitudinal dynamics into velocity and altitude subsystems. As for the velocity subsystem, the adaptive control is proposed via dynamic inversion method using neural network. To deal with input constraints, the additional compensation system is employed to help engine recover from input saturation rapidly. The highlight is that high order integral chained differentiator is used to estimate the newly defined variables and an adaptive neural controller is designed for the altitude subsystem where only one neural network is employed to approximate the lumped uncertain nonlinearity. The altitude subsystem controller is considerably simpler than the ones based on backstepping. It is proved using Lyapunov stability theory that the proposed control law can ensure that all the tracking error converges to an arbitrarily small neighborhood around zero. Numerical simulation study demonstrates the effectiveness of the proposed strategy, during the morphing process, in spite of some uncertain system nonlinearity. [ABSTRACT FROM AUTHOR]

Sodium intake shows a positive correlation with blood pressure, resulting in an increased risk for cardiovascular diseases (CVD). Salt reduction is a key step toward the WHO's goal of 25% reduction in mortality from non‐communicable diseases (NCDs) by 2025. This study aims to assess the current condition and temporal changes of the global CVD burden due to high sodium intake (HSI). We extracted data from the Global Burden of Disease (GBD) study 2019. The numbers and age‐standardized rates of mortality and disability‐adjusted life‐years (DALYs), stratified by location, sex, and socio‐demographic Index (SDI), were used to assess the high sodium intake attributable CVD burden from 1990 to 2019. The relationship between the DALYs rates and related factors was evaluated by stepwise multiple linear regression analysis. Globally, in 2019, the deaths and DALYs of HSI‐related CVD were 1.72 million and 40.54 million, respectively, increasing by 41.08% and 33.06% from 1990. Meanwhile, the corresponding mortality and DALYs rates dropped by 35.1% and 35.2%, respectively. The high‐middle and middle SDI quintiles bore almost two‐thirds of CVD burden caused by HSI. And the leading cause of HSI attributable CVD burden was ischemic heart disease. Universal health coverage (UHC) was associated with the DALYs rates after adjustment. From 1990 to 2019, the global CVD burden attributable to HSI has declined with spatiotemporal and sexual heterogeneity. However, it remains a major public health challenge because of the increasing absolute numbers. Improving UHC serves as an effective strategy to reduce the HSI‐related CVD burden. [ABSTRACT FROM AUTHOR]

This paper focuses on a single neural network tracking control for a class of nonlinear strict-feedback systems with input dead-zone and time-varying output constraint via prescribed performance method. To release the limit condition on previous performance function that the initial tracking error needs to be known, a new modified performance function is first constructed. Further, to reduce the computational burden of traditional neural back-stepping control approaches which require all the virtual controllers to be necessarily carried out in each step, the nonlinear items are transmitted to the last step such that only one neural network is required in this design. By regarding the input-coefficients of the dead-zone slopes as a system uncertainty and introducing a new concise system transformation technique, a composite adaptive neural state-feedback control approach is developed. The most prominent feature of this scheme is that it not only owes low-computational property but also releases the previous limitations on performance function and is capable of guaranteeing the output confined within the new form of prescribed bound. Moreover, the closed-loop stability is proved using Lyapunov function. Comparative simulation is induced to verify the effectiveness. [ABSTRACT FROM AUTHOR]

Atrial fibrillation/atrial flutter (AF/AFL) has progressed to be a public health concern, and high systolic blood pressure (HSBP) remains the leading risk factor for AF/AFL. This study estimated the HSBP attributable AF/AFL burden based on the data from the Global Burden of Disease (GBD) study 2019. Numbers, age‐standardized rates (ASR) of deaths, disability‐adjusted life years (DALYs), and corresponding estimated annual percentage change (EAPC) were analyzed by age, sex, sociodemographic index (SDI), and locations. Gini coefficient was calculated to evaluate health inequality. Globally, HSBP‐related AF/AFL caused 107 091 deaths and 3 337 876 DALYs in 2019, an increase of 142.5% and 105.9% from 1990, respectively. The corresponding mortality and DALYs ASR declined by 5.8% and 7.7%. High‐income Asia Pacific experienced the greatest decrease in mortality and DALYs ASR, whereas the largest increase was observed in Andean Latin America. Almost half of the HSBP‐related AF/AFL burden was carried by high and high‐middle SDI regions, and it was experiencing a shift to lower SDI regions. A negative correlation was detected between EAPC and SDI. Females and elderly people tended to have a higher AF/AFL burden, whereas young adults (30–49 years old) experienced an annual increase in AF/AFL burden. The Gini index of DALYs rate decreased from 0.224 in 1990 to 0.183 in 2019. Despite improved inequality having been observed over the past decades, the HSBP‐related AF/AFL burden varied across regions, sexes, and ages. Cost‐effective preventive, diagnostic, and therapeutic tools are required to be implemented in less developed regions. [ABSTRACT FROM AUTHOR]

Abstract A proactive fault detection and diagnosis (FDD) method is proposed for variable-air-volume (VAV) terminals in this study to overcome the problem of diagnostic information poor. The basic idea is to produce additional diagnostic information proactively through introducing specific disturbances to the suspected VAV terminal. The dynamic responses of the VAV terminal, which can be observed from the measurements and control signals, are helpful in isolating faults which are challenging for the conventional passive FDD methods. A list of proactive actions is designed to introduce the smallest disturbances into indoor environment. Therefore, the proposed method can work during office hours. Without loss of generality for practical applications, the proactive actions change the zone air temperature set-point only. The proposed method can be implemented in both building management systems and VAV terminal controllers. Evaluations are made on a simulated VAV system on Dymola platform. Results show that the method can improve FDD performance significantly. [ABSTRACT FROM AUTHOR]

• A quasi-three-dimensional model for performance of micro-channel SHP is developed. • Refrigerant flow among tubes is modeled as uneven flow with fixed direction in tube. • Air flow is modeled as uneven inlet flow with fixed direction across heat exchanger. • The model predicts micro-channel SHP heat capacity with average deviation below 5%. Micro-channel separated heat pipes (micro-channel SHPs), which may cycle without inputting additional electrical power, have shown their advantages of energy saving and compact structure, and they are preferred in the cooling of electronic equipment with narrow inner space. The non-uniformly distributed refrigerant flow among multiple flat tubes and air flow among multiple fins of micro-channel heat exchangers may have a significant effect on the performance of SHPs. In this study, a quasi-three-dimensional distributed parameter model of micro-channel SHPs is proposed for predicting the effects of non-uniformly distributed refrigerant and air flows on the performance. The model is developed by modeling all the components of a micro-channel SHP, i.e. an evaporator, an ascending tube, a condenser and a descending tube, respectively. In the model, the refrigerant flow is described as uneven flow among tubes and the flow direction is fixed inside each tube; the air flow is modelled as the flow with two-dimensional uneven distribution at the windward of heat exchanger and with the fixed direction across the heat exchanger; the three-dimensional partition method is applied to the control volume partition of flat tubes and fins. The proposed model is validated by experiments, and the results show that the deviations between simulated and experimental data of the heat transfer capacity, the temperature difference of micro-channel SHP, the outlet air temperature of evaporator and the outlet air temperature of condenser are 4.6%, 0.9 °C, 1.1 °C and 0.4 °C, respectively. [ABSTRACT FROM AUTHOR]