Heterogeneous sensor networks (HSN) find a wide range of applications in the field of military and civilian environments, where sensor nodes are utilized to estimate the position of a target with both dynamics and control input being unknown for the purposes of tracking. In the HSN, nodes are considered active depending upon their ability to sense the target output while the others are taken passive. Accurate estimation requires local information exchange among the spatially located sensor nodes, so that the active nodes as well as the passive nodes converge simultaneously to the same value. The local information exchange among the nodes is dictated by a connected graph. By using the criterion of collective observability, a novel distributed adaptive estimation scheme is introduced via adaptive observer where the nodes are allowed to have different sensor modalities. Using the estimated information, a subset of active and passive nodes, referred to as mobile nodes, can track the moving target. By using a constant state feedback controller at each mobile node, the state and parameter estimation as well as the tracking errors are shown to be uniformly ultimately bounded. Simulation results verify theoretical claims. 相似文献
The nickel sulphide (NiS) nanoparticles were synthesised by microwave-assisted-solvothermal method, pure Polyaniline (PANI) and Polyaniline with NiS (NiS–PANI) were synthesized at various weight percentages of NiS such as 1%, 5% and 15% by the oxidation polymerization method. The XRD pattern of NiS nanoparticles confirmed the formation of hexagonal structure, and its particle size was estimated by the Debye–Scherrer formula as 19 nm. The UV–visible absorption spectra recorded 200–1200 nm wavelength region and the bandgap was calculated from Tauc Plot. The morphology of PANI and NiS–PANI composites were observed as non-homogenous and agglomerated by field emission scanning electron microscope (FESEM). The FTIR spectra confirm the functional groups of the synthesized materials. The LCZ parameters were measured with the frequency of (1 Hz (hertz)–1 MHz (megahertz)) at room temperature was carried out, and the dielectric loss, dielectric constant, modulus plot and AC conductivity parameters were calculated for synthesized materials.
Thermally and chemically stable perovskite-like layer structures have attracted extensively in the field of energy and environmental applications. In this study, La2Ti2O7 was synthesized by the solvothermal method at 180 °C. This method provides high pure and homogeneously dispersed nanorods of orthorhombic phase having length of 250 nm and width of 70 nm. Even though this is a low-temperature synthesis method, it yields high crystalline nature after calcination. The novelty of this work is its synthesis methodology by the solvothermal route to achieve lower weight loss of La2Ti2O7. Furthermore, they exhibit narrow absorption in the UV-region from 200 to 350 nm, makes it possible to fabricate it as UV photodetector at ambient condition. In presence of UV illumination at 390 nm, it shows sharp photocurrent response with the decay time of 1.7 s.
Fourier-Transform Infrared Spectroscopy (FTIR) employs a unique approach tooptical diagnosis of tissue pathology based on the characteristic molecularvibrational spectra of the tissue. The biomolecular changes in the cellularand sub-cellular levels developing in abnormal tissue, including a majorityof cancer forms, manifest themselves in different optical signatures, whichcan be detected in infrared microspectroscopy. This report has two parts. Inthe first part, we report studies on normal, premalignant (polyp) andmalignant human colonic tissues from three patients with different stages ofmalignancy. Our method is based on microscopic infrared study (FTIR-microscopy)of thin tissue specimens and a direct comparison with traditional histopathologicalanalysis, which serves as a gold reference. The limited dataavailable showed normal colonic tissue has a stronger absorption thanpolypoid tumor and cancerous types over a wide region in a total of 100measurements. Detailed analysis showed that there is a significant decreasein total carbohydrate, phosphate and possibly creatine contents for polyp andcancerous tissue types in comparison to the controls. The same trend is maintainedin seven other patients studied. The second part consists of an analysis showingthe influence of various independent factors such as age, sex and grade of malignancy. Ourpreliminary results suggest that among the above three factors, age and gradeof malignancy have significant effect on the metabolites level, but sex has onlyminor effect on the measured spectra. Initial results on Linear DiscriminantAnalysis (LDA) showed good classification between normal and malignant cellsof human colonic tissues. 相似文献
In this paper, two novel energy-efficient rate adaptation schemes are presented. The proposed protocols use the Distributed
Power Control (DPC) algorithm to predict the channel state and determine the necessary transmission power which optimizes
the energy consumption. The first proposed rate adaptation scheme heuristically alters the modulation rate to balance the
energy-efficiency and the required throughput which is estimated with queue fill ratio. Moreover, the back-off scheme is incorporated
to mitigate congestion and reduce packet losses due to buffer overflows thus minimizing energy consumption. Consequently,
the nodes will conserve energy when the traffic is low, offer higher throughput when needed and save energy during congestion
by limiting transmission rates. The second rate adaptation scheme employs dynamic programming (DP) principle to analytically
select modulation rate and a burst size to be used during transmission. The proposed quadratic cost-function minimizes the
energy consumption while alleviating network congestions and buffer overflows. The proposed DP solution renders a Riccati
equation ultimately providing an optimal rate selection. The simulation results indicate that an increase in throughput by
96% and energy-efficiency by 131% is observed when compared to other available protocols, for example Receiver Based AutoRate
(RBAR).
In situ transmission electron microscopy straining experiments with concurrent macroscopic stress–strain measurements were performed to study the effect of microstructural heterogeneity on the deformation behavior of nanocrystalline metal films. In microstructurally heterogeneous gold films (mean grain size dm = 70 nm) comprising randomly oriented grains, dislocation activity is confined to relatively larger grains, with smaller grains deforming elastically, even at applied strains approaching 1.2%. This extended microplasticity leads to build-up of internal stresses, inducing a large Bauschinger effect during unloading. Microstructurally heterogeneous aluminum films (dm = 140 nm) also show similar behavior. In contrast, microstructurally homogeneous aluminum films comprising mainly two grain families, both favorably oriented for dislocation glide, show limited microplastic deformation and minimal Bauschinger effect despite having a comparable mean grain size (dm = 120 nm). A simple model is proposed to describe these observations. Overall, our results emphasize the need to consider both microstructural size and heterogeneity in modeling the mechanical behavior of nanocrystalline metals. 相似文献
Temporary International Collective (TIC) was established in 1972 by an agreement among seven countries, namely, Bulgaria, Czechoslovakia, Germany, Hungary, Poland, Romania and Union of Soviet Socialist Republics. The main objective of TIC was to provide the experimental data for the reactor physics analysis of water cooled and water moderated power reactors (WWER). Extensive experimental work for different core configurations was carried out by TIC countries to investigate the physics behaviour of WWER lattices and the results were published in TIC volumes. 相似文献
Exercising complementary roles of polymer-coated magnetic nanoparticles for precise drug delivery and image contrast agents has attracted significant attention in biomedical applications. The objective of this study was to prepare and characterize magnetic nanoparticles embedded in polylactide-co-glycolide matrixes (PLGA-MNPs) as a dual drug delivery and imaging system capable of encapsulating both hydrophilic and hydrophobic drugs. PLGA-MNPs were capable of encapsulating both hydrophobic and hydrophilic drugs in a 2:1 ratio. Biocompatibility, cellular uptake, cytotoxicity, membrane potential, and apoptosis were carried out in two different cancer cell lines (MCF-7 and PANC-1). The molecular basis of induction of apoptosis was validated by Western blotting analysis. For targeted delivery of drugs, targeting ligand such as Herceptin was used, and such a conjugated system demonstrated enhanced cellular uptake and an augmented synergistic effect in an in vitro system when compared with native drugs. Magnetic resonance imaging was carried out both in vitro and in vivo to assess the efficacy of PLGA-MNPs as contrast agents. PLGA-MNPs showed a better contrast effect than commercial contrast agents due to higher T(2) relaxivity with a blood circulation half-life ~ 47 min in the rat model. Thus, our results demonstrated the dual usable purpose of formulated PLGA-MNPs toward either, in therapeutics by delivering different hydrophobic or hydrophilic drugs individually or in combination and imaging for cancer therapeutics in the near future. 相似文献
Radionuclides content in the discharged fuel of the conceptual thorium breeder reactor ATBR-600 has been assessed and compared against other thermal power reactors considered in Indian nuclear power programme. The contribution of actinides and the fission products inventories in the discharged fuels are separately estimated and assessed. The ATBR-600 reactor is suggested for closed fuel cycle option. The relatively large presence of the unspent plutonium would in fact be recycled. Nonetheless, the data has been presented in the event of operating ATBR-600 like other present day power reactors in a once through fuel cycle mode. 相似文献