12 research outputs found
AC Equivalent Circuit Model of an Electrochemical Accelerometer for 3D Numerical Simulation in the Low-Frequency Range
AC Equivalent Circuit Model of an Electrochemical Accelerometer for 3D Numerical Simulation in the Low-Frequency Range
The electrochemical principles presented in this paper can be applied to the manufacture of vibration sensors for oil and gas exploration, as well as long-period vibration sensors for the observation of natural earthquakes. To facilitate the manufacture of high-volume electrochemical accelerometer (EAM), this paper presents an AC equivalent circuit model of an EAM in a low-frequency range. A 3D time-dependent numerical simulation based on finite element analysis was designed to combine a complex chemical reaction with electric circuit theory. A sensitive chip channel model was constructed by using partial differential equations and the problem caused by a designed mathematical model was solved by using multi-physics finite element analysis. When the electrochemical properties of an electrochemical vibration sensor and its design parameters as well as the parameters of the AC equivalent circuit model are considered, the abstract processing of the sensor on the equivalent circuit is better accomplished. The effectiveness of the proposed simulation model and the equivalent circuit model were verified by comparing the amplitude-frequency characteristic curve of the equivalent circuit with the amplitude-frequency characteristic curve of the single-channel simulation model of the sensitive chip. These model not only have great significance for the design guidance of an external conditioning circuit but also provide an effective method to decouple the output signal and noise of the sensor reaction cavity
Switching from biosimilar (Basalin) to originator (Lantus) insulin glargine is effective in Chinese patients with diabetes mellitus: a retrospective chart review [version 1; referees: 3 approved, 1 approved with reservations]
Background: This study investigated the effectiveness and safety of switching from BasalinĀ® to LantusĀ® in Chinese patients with diabetes mellitus (DM). Methods: Ā A retrospective chart review conducted using the electronic medical records of patients hospitalized at the Qingdao Endocrine and Diabetes Hospital from 2005 to 2016. All patients were diagnosed with DM and underwent switching of insulin from Basalin to Lantus during hospitalization. Data collected included fasting (FBG), pre- and post-prandial whole blood glucose, insulin dose, reasons for insulin switching and hypoglycemia. Four study time points were defined as: hospital admission, Basalin initiation, insulin switching (date of final dose of Basalin), and hospital discharge. Blood glucose measurements were imputed as the values recorded closest to the dates of these four time points for each patient. Results: Data from 73 patients (70 patients with type 2 diabetes, 2 with type 1, and 1 undisclosed) were analyzed. At admission, mean glycated hemoglobin (HbA1c) and FBG were 8.9% (SD=1.75) and 9.98 (3.22) mmol/L, respectively. Between Basalin initiation and insulin switch, mean FBG decreased from 9.68 mmol/L to 8.03 mmol/L (p<0.0001), over a mean 10.8 (SD=6.85) days of Basalin treatment, and reduced further to 7.30 mmol/L at discharge (p=0.0116) following a mean 6.6 (7.36) days of Lantus. The final doses of Basalin and Lantus were similar (0.23 vs. 0.24 IU/kg/day; p=0.2409). Furthermore, reductions in pre- and post-prandial blood glucose were also observed between Basalin initiation, insulin switch and hospital discharge. The incidence of confirmed hypoglycemia was low during Basalin (2 [2.4%]) and Lantus (1 [1.2%]) treatment, with no cases of severe hypoglycemia. Conclusion: In this study population, switching from Basalin to Lantus was associated with further reductions in blood glucose, although the dose of insulin glargine did not increase. Further studies are required to verify these findings and determine the reason for this phenomenon
A Novel Probabilistic Approach to Optimize Stand-Alone Hybrid Wind-Photovoltaic Renewable Energy System
In the present study, a novel probabilistic approach is proposed to optimize a stand-alone hybrid wind-photovoltaic renewable energy system installed in the South China Sea. In detail, the probability distribution of power generated from a hybrid wind-photovoltaic system is estimated based on the probabilistic descriptions of wind and solar energy resources in the South China Sea. In addition, the present study proposed a battery level coefficient model to calculate the battery capacity of the hybrid system. As the battery level coefficient implies the expected power deficit in a specific continuous duration, it reflects the reliability of the battery system and, hence, the performance of the system under the power deficit condition. Given the probabilistic models estimated the stability of power generations, a genetic algorithm is applied to optimize the sizes of the system components (the installed capacities of wind turbines and photovoltaic modules and the load) when the levelized cost of energy (LCOE) is used as the indicator. The optimization verifies that the proposed probabilistic approach provides reasonable estimates of the power generation of a hybrid system in an optimization process. In addition, the comparisons with the conventional deterministic approach implies that the widely used loss of power supply probability (LPSP) could be interpreted, in a statistical sense, as the expected duration of power deficit. More importantly, the LPSP is connected to the localized sea condition, and therefore, this stability assessment criterion should be specified according to the location where the system is installed
Synthesis of Bismuth Ferrite Nanoparticles via a Wet Chemical Route at Low Temperature
Nanoparticles (NPs) of multiferroic bismuth ferrite (BiFeO3) with narrow size distributions were synthesized via a wet chemical route using bismuth nitrate and iron nitrate as starting materials and excess tartaric acid and citric acid as chelating agent, respectively, followed by thermal treatment. It was found that BiFeO3 NPs crystallized at ā¼350āC when using citric acid as chelating agent. Such crystallization temperature is much lower than that of conventional chemical process in which other types of chelating agent are used. BiFeO3 NPs with different sizes distributions show obvious ferromagnetic properties, and the magnetization is increased with reducing the particle size
Effectiveness of stocking Sparus macrocephalus fry in situ in the East China Sea
The sea area surrounding Baishishan Island has abundant fishery resources because of its plentiful food and rocky reefs that provide refuge from predators. However, overfishing has occurred in many areas and some speciesā local populations need to be replenished through stocking programs. This case study, using Sparus microcephalus as the test species, designed and analyzed detailed stocking strategies to improve the survival ratio and control the active range of the released fishes. Controlled variables included release location, release time, and tidal level. Two stocking strategies were designed, executed, and evaluated for comparison. A traditional stocking method was applied to the high flow area of Baishishan Island in Xiangshan Bay, East China Sea. The released fry were transported by boat and released to the sea using buckets. Released fish were traced using plastic tags. The average distance of the 19 recaptured fry from the release point was 7.6Ā km with 52.9% mortality rate. The distance at recapture and mortality rate among recaptured individuals showed that the traditional releasing method was not successful. An in situ stocking method was used in a low tide area and natural process was imitated to decrease the stress response and promote physiological adaptation. The purpose of this method was to prolong the release process applying temporary net cages at the release location, which resulted in a regional distribution of the released fish and possibly improving the food availability. A new SrĀ +Ā tagging technique was adopted to evaluate the release effect and quantify comparative release data. Only 1 fish among the 354 caught was found farther than 1 km from the release point in the following 6 months. The results validated the promotion of the new stocking technique. Keywords: Baishishan island, Sparus macrocephalus, Sr+ tagging technique, In situ release, Survival rat