Dynamic analysis of multi point winding hoisting system under non synchronous movements of wire ropes in deep well

Taking the multi point winding hoisting system with depth of 1000 m, drum radius of 0.4 m, drum radius difference of 0.1 mm as the research background, a model of multi point winding hoisting system under non synchronous movement of wire ropes is established, and the mathematical model is deduced by Lagrange equation. Then the dynamic characteristic of super deep multi point winding hoisting system under non synchronous movements of wire ropes is analyzed. The results show that: the rotational displacement of mass block is 5°, the rotational velocity is 0.07 °/s in the stage of constant speed. The rope length difference reaches 0.07 m, the tension of each wire rope changes 333 N, accounted for about 7 % of the average tension. And with the length difference increasing 35 mm, the force differences increasing 320 N, which indicates that the length difference has great impact on the tension difference of wire ropes. Finally, the mathematical model is verified through experiment

Analysis of transverse vibration of wire rope in flexible hoisting system

Taking the flexible hoisting system as the research object, the transverse vibration mathematical model of the steel wire rope of the winding hoisting system is established, and the transverse vibration displacement, velocity and acceleration of the steel wire rope at 18 m away from one end of the wire rope under the sine excitation at other end is obtained through the comparison and verification of the results from the mathematical model, mechanical model and experiment. The results show that: for the length of the wire rope of 20 m, under the sine excitation at the end of amplitude of 0.002 m and frequency of 20 Hz, the transverse vibration displacement at 2 m from one end of the wire rope with length of 20 m is basically between –0.005 m and 0.005 m, the transverse vibration velocity at 2 m from one end of the wire rope is basically between –0.04 m/s and 0.04 m/s, and the transverse vibration acceleration of the wire rope is basically between –0.5 m/s2 and 0.5 m/s2. And the transverse vibration displacement decreases near the end, meanwhile the transverse vibration frequency increases with the reduction of length of vertical section of wire rope

A Fast Method for Calculation of Marine Gravity Anomaly

Gravity data have been playing an important role in marine exploration and research. However, obtaining gravity data over an extensive marine area is expensive and inefficient. In reality, marine gravity anomalies are usually calculated from satellite altimetry data. Over the years, numerous methods have been presented for achieving this purpose, most of which are time-consuming due to the integral calculation over a global region and the singularity problem. This paper proposes a fast method for the calculation of marine gravity anomalies. The proposed method introduces a novel scheme to solve the singularity problem and implements the parallel technique based on a graphics processing unit (GPU) for fast calculation. The details for the implementation of the proposed method are described, and it is tested using the geoid height undulation from the Earth Gravitational Model 2008 (EGM2008). The accuracy of the presented method is evaluated by comparing it with marine shipboard gravity data. Its efficiency is demonstrated through comparison with the conventional sequential method. The tests demonstrate that the proposed method can be employed for accurately calculating marine gravity anomalies and provides an advantage on computational efficiency

Association of Nap Duration after Lunch with Prevalence of Metabolic Syndrome in a Chinese Government Employee Population

Metabolic syndrome is an important risk factor for cardiovascular disease, type 2 diabetes mellitus, and all-cause mortality. However, the relationship between napping and metabolic syndrome remains contradictory. The aim of this study was to evaluate the association between nap duration after lunch and prevalence of metabolic syndrome, and subgroup differences in the associations among a government employee population. A total of 5129 participants (mean age 39.4 years) were included in this study. Nap duration after lunch was self-reported, and metabolic syndrome was defined according to the Joint Interim Statement in 2009. Multivariate logistic regression models and adjusted restricted cubic spline functions were used to examine the association and dose-response relationship between nap duration after lunch and prevalence of metabolic syndrome. Of the participants, 17.3% had metabolic syndrome and 81.4% were habitual nappers. Adjusted odds ratio (OR) (95% confidence interval (CI)) of metabolic syndrome for longer nap duration (>90 min) per day was 1.77 (95% CI 1.09 to 2.89), compared with reference (~30 min). Results of stratification analyses indicated the association was found only among females (OR 3.02, 95% CI 1.38 to 6.57), participants without mood symptoms (OR 1.97, 95% CI 1.19 to 3.25), and those having longer night sleep duration (≥8 h) (OR 2.34, 95% CI 1.20 to 4.56). Longer nap duration was also associated with components of metabolic syndrome, including elevated waist circumference, elevated fasting plasma glucose, and elevated triglycerides. In conclusion, longer nap duration after lunch was associated with a higher prevalence of metabolic syndrome in females, people without mood symptoms, and people having longer night sleep duration

Evaluation of the Brewing Characteristics, Digestion Profiles, and Neuroprotective Effects of Two Typical Se-Enriched Green Teas

As a functional beverage, selenium (Se)-enriched green tea (Se-GT) has gained increasing popularity for its superior properties in promoting health. In this study, we compared the brewing characteristics, in vitro digestion profiles, and protective effects on neurotoxicity induced through the amyloid-beta (Aβ) peptide of two typical Se-GTs (Enshi Yulu (ESYL) and Ziyang Maojian (ZYMJ), representing the typical low-Se green tea and high-Se green tea, respectively). ESYL and ZYMJ showed similar chemical component leaching properties with the different brewing methods, and the optimized brewing conditions were 5 min, 90 °C, 50 mL/g, and first brewing. The antioxidant activities of the tea infusions had the strongest positive correlation with the tea polyphenols among all of the leaching substances. The tea infusions of ESYL and ZYMJ showed similar digestive behaviors, and the tea polyphenols in the tea infusions were almost totally degraded or transferred after 150 min of dynamic digestion. Studies conducted in a cell model of Alzheimer’s disease (AD) showed that the extract from the high-Se green tea was more effective for neuroprotection compared with the low-Se green tea. Overall, our results revealed the best brewing conditions and digestion behaviors of Se-GT and the great potential of Se-GT or Se-enriched green extract (Se-GTE) to be used as promising AD-preventive beverages or food ingredients

Full Current-Type Control-Based Hybrid Energy Storage System

With greater power density, a hybrid power source that combines supercapacitors and batteries has a wide range of applications in pulse-operated power systems. In this paper, a supercapacitor/battery semi-active hybrid energy storage system (HESS) with a full current-type control strategy is presented. The studied HESS is composed of batteries, supercapacitors, and a bidirectional buck–boost converter. The converter is controlled such that supercapacitors supply load power pulses, and batteries provide the power in steady state. To realize the fast compensation of the supercapacitors to the load power pulses, a power distribution module based on hysteresis control theory is designed in the control system. Moreover, the control strategy does not require the model parameters of the converter and supercapacitors, so the control system is simplified. A complete configuration scheme and cost analysis of the proposed HESS are also presented. Obtained results show that the proposed supercapacitor/battery semi-active HESS has good performance in terms of dynamic response, weight, and energy utilization coefficient (EUC)

Full Current-Type Control-Based Hybrid Energy Storage System

With greater power density, a hybrid power source that combines supercapacitors and batteries has a wide range of applications in pulse-operated power systems. In this paper, a supercapacitor/battery semi-active hybrid energy storage system (HESS) with a full current-type control strategy is presented. The studied HESS is composed of batteries, supercapacitors, and a bidirectional buck–boost converter. The converter is controlled such that supercapacitors supply load power pulses, and batteries provide the power in steady state. To realize the fast compensation of the supercapacitors to the load power pulses, a power distribution module based on hysteresis control theory is designed in the control system. Moreover, the control strategy does not require the model parameters of the converter and supercapacitors, so the control system is simplified. A complete configuration scheme and cost analysis of the proposed HESS are also presented. Obtained results show that the proposed supercapacitor/battery semi-active HESS has good performance in terms of dynamic response, weight, and energy utilization coefficient (EUC)

Recent Advances in Biotransformation of Saponins

Saponins are a class of glycosides whose aglycones can be either triterpenes or helical spirostanes. It is commonly recognized that these active ingredients are widely found in various kinds of advanced plants. Rare saponins, a special type of the saponins class, are able to enhance bidirectional immune regulation and memory, and have anti-lipid oxidation, anticancer, and antifatigue capabilities, but they are infrequent in nature. Moreover, the in vivo absorption rate of saponins is exceedingly low, which restricts their functions. Under such circumstances, the biotransformation of these ingredients from normal saponins—which are not be easily adsorbed by human bodies—is preferred nowadays. This process has multiple advantages, including strong specificity, mild conditions, and fewer byproducts. In this paper, the biotransformation of natural saponins—such as ginsenoside, gypenoside, glycyrrhizin, saikosaponin, dioscin, timosaponin, astragaloside and ardipusilloside—through microorganisms (Aspergillus sp., lactic acid bacteria, bacilli, and intestinal microbes) will be reviewed and prospected