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51.
52.
Journal of Failure Analysis and Prevention - In this study, the effect of tool rotational speed on mechanical properties of AA 6082-T6 aluminum alloy was investigated. Different welded joints were...  相似文献   
53.
Journal of Superconductivity and Novel Magnetism - Electronic and magnetic properties of CdS-based, doped by various transition metal elements (Ti, V, Cr, Mn, Fe, Co or Ni), dilute magnetic...  相似文献   
54.
Neural Computing and Applications - Microgrid systems are becoming a very promising solution to meet the power demand growth especially in remote areas where diesel generators (DG) are commonly...  相似文献   
55.
Information Systems and e-Business Management - Today’s business entities face an ever-growing number of laws and regulations due to recent high profile business scandals and failures. Small...  相似文献   
56.
Summary: This paper reports the phase behavior of photochemically crosslinked poly(butyl acrylate) networks in nematic liquid crystal (LC) solvents. The swelling properties are studied as a function of temperature for two low molecular weight nematic LCs, 4‐cyano‐4′‐pentylbiphenyl (5CB) and the eutectic mixture of cyanoparaphenylenes (E7). Chemically crosslinked polymer networks were formed by the UV radiation of initial solutions of the reactive monomer, butyl acrylate, a crosslinker (hexanediol diacrylate), and a photoinitiator. To obtain different network densities, the ratio of butyl acrylate to hexanediol diacrylate was varied prior to polymerization/crosslinking reactions. Immersion in an excess of the LC solvent allowed for the measurement of size increase by polarized optical microscopy in terms of temperature. Length, width, and diagonal ratios were calculated considering swollen to dry network states of the samples. In general, swelling leads to an increase in the network size by increasing the temperature with a significant dependence on the degree of crosslinking. A large shift in the swelling ratio was found in the vicinity of the nematic to isotropic transition temperatures of the LCs.

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57.
The most common noises in ECG (electrocardiogram) signal processing are BW (baseline wandering) and the 50 or 60 Hz PLI (power line interferences). In order to remove these two major source of noises, we have used the recent powerful DWT (discrete wavelet transform) signal processing in ECG signals which are obtained from MIT-BIH Arrhythmia Database. The results indicate that DWT is a good method for filtering noises without changing the morphology of ECG, and can be applied to all types of ECG signals, whether normal or presenting arrhythmias.  相似文献   
58.
This paper tackles the problem of pilot contamination (PC) in mmWave Massive MIMO cellular systems. We propose an analog precoder based on antenna subset transmission technique to mitigate the PC. This technique ensures the interfering signal to become noise‐like signal thus helping a more efficient estimation of channel coefficients. Also, this strategy is low cost and introduces no complexity load. The result shows the effectiveness of the proposed precoder to mitigate PC issue.  相似文献   
59.
In this paper, testing of radio frequency (RF) devices with mixed-signal testers is discussed. General purpose automatic test equipment (ATE) will be used. In this paper, a more universal test structure utilizing RF building blocks is proposed. A global positioning system (GPS) device is used as an example to illustrate how to develop the RF test plan with this usage. The test plan developed includes fast, cost-effective and dedicated circuitry.
Jing LiEmail:
  相似文献   
60.
The oxidative degradation of PP/OMMT nanocomposites under γ‐irradiation was studied. Changes in structure and properties resulting from γ‐exposure in the range 0–100 kGy were investigated. The results were analyzed by comparing the influence of PP‐g‐MA and pristine OMMT on the oxidation kinetics of neat PP. γ‐Irradiation in the presence of air strongly degraded the properties of PP materials, particularly for radiation doses above 20 kGy. The rate of oxidative degradation of PP/OMMT/PP‐g‐MA nanocomposites was much faster than that of neat PP. This suggests that PP‐g‐MA and pristine OMMT components behave as oxidation catalysts, leading to the formation of free radicals in the polymer matrix.

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