Optic-Fiber Temperature Sensor

As an important parameter in industry, agriculture, biomedical, and aerospace, temperature possesses a significant position for the development of our society. Thus, it has become a hot point to develop novel sensors for temperature monitoring. Compared with traditional electronic sensors, optical fiber sensors break out for the compact structure, corrosion resistance, multiplex and remote sensing capability, cheap prices, and large transmission capacity. Especially the phase modulation type optical fiber sensors attract much attention for the fast and accurate measurement of the external parameters in a large dynamic measurement range. In this work, we review the optical fiber Mach-Zehnder interferometer (MZI) for temperature sensing which is widely used these years. The fundamental principles of MZI fiber sensors are proposed and discussed to further understand MZI. Different kind of structures for temperature sensing of recent years are summarized as several typical MZI categories and their advantages and disadvantages are indicated separately. Finally, we make a conclusion of the MZI temperature sensing and several methods typically to realize the MZI in practical application for the readers

Networked Non-fragile H∞ Control for Lipschitz Nonlinear System with Quantization and Packet Dropout in Both Feedback and Forward Channels

The networked non-fragile H∞ control problem for Lipschitz nonlinear system with quantization and packet dropout in both feedback and forward channels is investigated in this paper. The sensor measurement and controller output are quantized by logarithmic quantizers before transmitted over the network. The packet transmissions in the communication channels from the sensor to the controller and from the controller to the actuator are modeled as Markov chains respectively. Based on the Lyapunov functional approach, the networked non-fragile H∞ controller is designed to stabilize the Lipschitz nonlinear system and achieve the prescribed H∞ performance. Finally a numerical example is provided to illustrate the effectiveness of the proposed method

Dynamic modeling and control of a novel XY positioning stage for semiconductor packaging

This paper presents the dynamic modeling and controller design of an XY positioning stage for semiconductor packaging. The XY stage is directly driven by two linear voice coil motors, and motion decoupling between the X and Y axes is realized through a novel flexible decoupling mechanism based on flexure hinges and preloaded spring. Through bond graph method, the dynamic models of X- and Y-axes servomechanisms are established, respectively, and the state space equations are derived. A control methodology is proposed based on force compensations and the performance of the XY stage is investigated by simulations and experimental tests. The results show that the XY stage has good performance. When the reference displacements are defined as 2 mm, the settling time of the X-axis movement is 64 ms, and the overshoot is 0.7%. Y-axis settling time is 62 ms, and the overshoot is 0.8%. X-axis positioning accuracy is 1.85 μm and the repeatability is 0.95 μm. Y-axis positioning accuracy and repeatability are 1.75 μm and 0.9 μm, respectively. In addition, the stage can track linear, circular and complex trajectories very well

Managing Diabetes Mellitus in Underserved Subjects of Western China Using a Telemedicine System— a Clinical Trial

Objective: To evaluate the effectiveness of Internet and telephone-based telemedicine system managing on patients’ glycemic index, blood pressure, and lipid level control in underserved subjects with type 2 diabetes in Western China. Research designs and methods: In a 3 years, randomized, controlled, single-blind, parallel-group treat-to-target study, 412 subjects with type 2 diabetes were randomized to telemedicine (Tel; n =208) group and usual care (control; n =204) group. We evaluated the effects of the intervention on blood sugar, blood pressure, and lipid levels at 1, 2, 3 years point, and investigated the cause of the loss during follow-up by phone call. Results: Intra-group comparison: in the Tel group, the FBS, 2HPG, HbA1c, and SBP at 1, 2, 3 years and DBP, TC, TG, BMI at 2, 3 years were significantly decreased compared with baseline level  (P<0.05). Moreover, the Tel group had an obvious better control of their HbA1c  at 2 and 3 years and 2HPG  at 3 years of follow-up respectively compared with the outcomes at 1 year (P<0.05).Inter-group comparison: the FBS, 2HPG, and HbA1c of Tel group decreased significantly from the baseline to the 1 year more than those of control group (P<0.05 or P<0.01 ). In this analysis, all clinical measures of Tel group had a significant downward compared with the outcomes of Control group  at 2 years, the FBS, HbA1c and BMI (P<0.001), the 2HPG and SBP (P<0.01) and DBP, TC, and TG (P<0.05) were statistically significant respectively. Logistic regression analysis showed that the subject loss during follow-up was associated with worse diabetes management (OR=3.842), low income (OR=3.201), low education level (OR=0.923), and greater distance to the hospital (OR=0.921).Conclusions: The study results indicated that the telemedicine may be a useful tool for managing diabetes mellitus

Microwave absorbing alkaline catalyst for biodiesel production via MIL-100(Fe): Catalytic optimization, characterizations, kinetics, and distillation simulation

Microwave heating (MW) is known for its efficacy in promoting transesterification for biodiesel production. However, the microwave-induced catalysis, linked to catalyst absorbing capability, remains poorly understood. Herein, a class of alkaline catalysts with strong microwave absorption were synthesized, validating their positive impact on transesterification. Various methods were used to reveal the relationship between microwave absorbing capacity and physicochemical properties of the synthesized catalyst (KF/Mg-MIL). Results indicated the previously recognized basicity’s role for KF/Mg-MIL was surpassed by microwave absorbing capability (permittivity and permeability) in MW (2.45 GHz). KF/Mg-MIL, with εr = 4.94′-j1.09″ and μr = 1.03′-j0.024″, efficiently transformed microwave into thermal energy via the dielectric loss and magnetic loss, saving 50 % energy consumption and reducing 1051.61 kg CO2 for per ton biodiesel compared to water bath heating (WB). Notably, “non-thermal” effect was observed with KF/Mg-MIL in MW, which reduced activation energy by 2.49 kJ/mol and increased the frequency factor by 793.32 min−1 in comparison to WB

Tuberculosis burden in China: a high prevalence of pulmonary tuberculosis in household contacts with and without symptoms

Background: In the context of decreasing tuberculosis prevalence in China, we examined the effectiveness of screening household contacts of tuberculosis patients. Methods: A tuberculosis survey was conducted in 2008. All 3,355 household contacts of notified tuberculosis cases were examined with a questionnaire interview, chest X-ray and three sputum smear tests. The effectiveness was examined by comparing the prevalence of pulmonary tuberculosis in household contacts with or without presenting clinical symptoms against the respective notification rates. Regression models were used to evaluate the factors associated with pulmonary tuberculosis. Results: Of the 3,355 household contacts, 92 members (2.7%) had pulmonary tuberculosis, among which 46 cases were asymptomatic. The prevalence of pulmonary tuberculosis and smear positive cases in household contacts without symptoms were 20 and 7 times higher than the notification rates in 2008, while those in household contacts with symptoms were 247 and 108 times higher than notification rates, respectively. The patients detected were mainly Index Cases’ spouses, sisters/brothers and those who were in contact with female Index Cases. Conclusions: The present study provides convincing evidence that household contacts of notified tuberculosis cases are at higher risk of developing tuberculosis. Routine screening for household contacts without any symptoms is recommended for sustained tuberculosis control in China as well as in the world