Wireless body area network (WBAN) has witnessed significant attentions in the healthcare domain using biomedical sensor-based monitoring of heterogeneous nature of vital signs of a patient’s body. The design of frequency band, MAC superframe structure, and slots allocation to the heterogeneous nature of the patient’s packets have become the challenging problems in WBAN due to the diverse QoS requirements. In this context, this paper proposes an Energy Efficient Traffic Prioritization for Medium Access Control (EETP-MAC) protocol, which provides sufficient slots with higher bandwidth and guard bands to avoid channels interference causing longer delay. Specifically, the design of EETP-MAC is broadly divided in to four folds. Firstly, patient data traffic prioritization is presented with broad categorization including Non-Constrained Data (NCD), Delay-Constrained Data (DCD), Reliability-Constrained Data (RCD) and Critical Data (CD). Secondly, a modified superframe structure design is proposed for effectively handling the traffic prioritization. Thirdly, threshold based slot allocation technique is developed to reduce contention by effectively quantifying criticality on patient data. Forth, an energy efficient frame design is presented focusing on beacon interval, superframe duration, and packet size and inactive period. Simulations are performed to comparatively evaluate the performance of the proposed EETP-MAC with the state-of-the-art MAC protocols. The comparative evaluation attests the benefit of EETP-MAC in terms of efficient slot allocation resulting in lower delay and energy consumption.
The initial stage of electrodeposition of manganese dioxide has been studied on the platinum disk electrode and on the ring-disk electrode. Two current maxima were observed on the anodic voltammograms. It has been shown that the first rise in the current is associated with the formation of manganese dioxide (MD) nuclei on the electrode surface, and the second with their growth at the border between MnO2 and bare platinum due to an increase in the perimeter of the nuclei. Electrodeposition on bare platinum proceeds at a higher rate than on the surface of growing MD. This is explained by the difference in the reaction mechanisms on these substrates. The first stage of the process on the growing MD is the chemisorption of Mn(II) ions with the formation of Mn(III) ions, which are then electrochemically oxidized to MD. Chemisorption is the slowest step in the whole process. 相似文献
K10Ga3Bi6.65 is the first representative in the ternary system A-Ga-Bi (A = alkali metal). It contains [Ga3Bi6]9– anions with planar triangular-coordinated Ga atoms as the main structural feature, accompanied by isolated Bi–Bi dumbbells. Alkali metal cations are counterbalancing the charges and fill the space between the anionic units. According to the Zintl-Klemm concept charge balance is reached if an almost equal ratio of single and double-bonded Bi2 dumbbells are present according to (K+)10[Ga3Bi6]9–([Bi-Bi]4–)1/6([Bi=Bi]2–)1/6. 相似文献
As a hot topic of global concern, the distinguishing and detecting of antibiotic pollution is crucial owing to its adverse effect on ecosystems and human health stemming from excessive use and poor management. Herein, a water-stable lanthanide coordination polymer sensor (Dy-TCPB) with multiple emitting centers is prepared. The versatile Dy-TCPB can conveniently differentiate various antibiotics, and displays a self-calibration luminescent response to nitrofurazone (NFZ) and furazolidone (FZD). Each antibiotic exhibits notable correlation to a unique combination of the two ligand-to-Dy ion emission intensity ratios, enabling two-dimensional fingerprint recognition. Furthermore, the novel self-calibration sensor demonstrates effective recognition of NFZ and FZD with excellent sensitivity and selectivity, and detection limits as low as 0.0476 and 0.0482 μm for NFZ and FZD, respectively. The synthetic approach for the fabrication of a singular coordination polymer exhibiting multiple emissions provides a promising strategy for the development of facile and effective ratiometric sensors. 相似文献