Effective solid-to-fluid heat transfer coefficient in EGS reservoirs

The present work developed a three-equation local thermal non-equilibrium model to predict the effective solid-to-fluid heat transfer coefficient in the enhanced geothermal system reservoirs based on the volume averaging method. Due to the high rock-to-fracture size ratio, the solid thermal resistance effect in the internal rocks cannot be neglected in the effective solid-to-fluid heat transfer coefficient. The present three-equation local thermal non-equilibrium model can consider the dynamic variation of the solid thermal resistance in transient heat transfer by introducing the penetration temperature difference. The model was validated by comparison with pore-scale numerical simulations and macro-scale LTNE model numerical simulations. The results show that the three-equation local thermal non-equilibrium model has a high accurac

Adsorption Properties of Copper (II) Ion From Aqueous Solution by Starch-Grafted Polyacrylamide and Crosslinked Starch-Grafted Polyacrylamide

Starch-grafted polyacrylamide (SA) and cross-linked starch-grafted polyacrylamide (CSA) had been synthesized via grafting polymerization from corn starch and used as adsorbents for the removal of Cu(II) ion from aqueous solution. The equilibrium, kinetics and thermodynamics of adsorption processes of SA and CSA were investigated and compared. It was found that the adsorption capacity of Cu(II) of SA and CSA could reach the maximum within 60 min when the pH was 6. The adsorption kinetics of CSA and SA for Cu(II) was favorably described by the pseudo-second-order kinetic model and the adsorption isotherm was described well with the Freundlich isotherm model. Thermodynamic studies indicated that the adsorption was a spontaneous and endothermic process with increased entropy, and the rise of temperature would benefit the adsorption; the enthalpy change(ΔH), the entropy change (ΔS) and free energy change (ΔG) of the adsorption process of Cu(II) on SA and CSA were calculated with adsorption isotherm data and basic thermodynamic relations

Robust Method for the Detection of Abnormal Data in Hydrography

Blunder detection is a topic of great interest to hydrographers because undetected blunders significantly distort the observed parameters, e.g., soundings. Based on an analysis of the characteristic of marine surveying, a robust method for the detection of abnormal data (include blunders) in hydrography is proposed in this paper, which is called the robust interpolation comparison test based on robust Mestimation by an iterative calculation procedure. Some questions involved in the implement of the suggested method are discussed in detail. Compared to the existing methods, the new method has more strong capacity of locating abnormal data. A simulation study and an actual numerical example for the process of multibeam soundings are given to test the performance of the proposed method. The results have illustrated the effectiveness of the method in the detection and identification of multiple blunders. The use of the new method will play an important role in improving the quality and reliability of marine measurements in our country

Hybrid CuCoO-GO enables ultrasensitive detection of antibiotics with enhanced laser desorption/ionization at nano-interfaces

The soaring concerns globally on antibiotic overuse have made calls for the development of rapid and sensitive detection methods urgent. Here we report that the hybrid CuCoO-GO matrix allows for sensitive detection of various antibiotics in combination with MALDI TOF MS. The new matrix is composed of few-layered GO nanosheets decorated with CuCoO nanoparticles with an average size of 10 nm, and exhibits excellent aqueous suspensibility. Accurate quantitation of the sulfonamide antibiotics in milk samples have been demonstrated using a CuCoO-GO matrix and a stable isotope (C13)-labeled analyte as the internal standard. Our experiments have achieved lower limits of detection (LOD) by several hundred fold for the detection of a panel of representative antibiotics, in comparison with the literature reports. Both intrabacterial and extrabacterial residual antibiotics can be sensitively detected with our method. We have further investigated the molecular mechanism of the enhanced desorption/ionization efficiency by the CuCoO-GO matrix with synchrotron radiation techniques for the first time. This work provides a sensitive matrix enabling MALDI-TOF MS to be applied in small molecular analysis, but also presents a distinct perspective on the mechanism behind the material functions

The Influence of Carrier's Attitude and the Position Reduction in Multibeam Echosounding and Airborne Laser Depth Sounding

Having finished the development of the multibeam echosounding system, China is making a great effort to develop an airborne laser depth sounding system. According to the principle of the two kinds of sounding system mentioned above, a series of position reduction formulas and their error equations are developed in this paper. The dynamic effect of marine sounding, i.e., the influence of carrier's attitude, is taken into full account in developing the equations. Finally, the real parameters of the two sounding systems developed by China are used to calculate the position reductions and their accuracies at different heading angles. The results show that the accuracies of depths and positions in multibeam echosounding and airborne laser depth sounding are dependent not only on their own sensors but also on the additional sensors

UHF RFID Tag Antenna Design for Challenging Environment Surfaces

We propose a low cost, long range UHF RFID tag antenna for challenging environment surfaces like metal, glass and a human body. It consists of a nested-slot based patch on upper substrate and parasitic parallel strips on the second grounded substrate. The parasitic strips provide isolation by exciting some multi-resonant modes in the presence of metal and high dielectric materials. Furthermore, the proposed design is suitable for platform-tolerant applications because it can work properly on general tagged objects such as metal, glass, and wood. Mounted on 200×200 mm 2 metal plate, the proposed tag covers whole US RFID band and a maximum read range of 9.5 m at 910 MHz