1,838 research outputs found
Fuzzy Based Vertical Handoff Decision Controller for Future Networks
— In Next generation wireless Networks, the received signals (RSS) from different networks do not have a same meaning since each network is composed of its specific characteristics and there is no common pilot signal. Then, RSS comparisons are insufficient for handoff decision and may be inefficient and impractical. A more complex decision criterion that combines a large number of parameters or factors such as monetary cost, bandwidth, and power consumption and user profile is necessary. Though there are a lot works available for vertical handoff decision (VHD) for wireless networks, the selection of best network is still challenging problem. In this paper we propose a Fuzzy based vertical handoff decision controller (FVHDC) Which performs handover decision based on the output of fuzzy based rules
An Extensive Proposal for Vertical Handoff Technique in WLAN
Vertical handoff is the one of the most powerful hidden weapon of the wireless network scenario. As the whole world of digital electronics is moving towards internet of things as result of this vertical handoff becomes a much needed seamless connectivity tool to enhance the paradigm. Now a days many of the digital electronic devices are been inventing to boost the smaller networks like in office, universities and companies. So an inverse arise of need for vertical handoff in the WLAN is on much priority like never before. Many of the systems are existed to provide vertical handoff without degrading or interrupting the data access facility in WLAN. In most of the vertical handoff mechanism the load is put on the mobile nodes to look over the data flow mechanism in the established WLAN. This may add some contribution to increase the delay in the delivery of the data in the established network. So as an efficient answer to this, this paper put forwards an idea of vertical handoff mechanism using the pool manger in the network and put the burden on the mangers to take care of the handoff process, so that the data delivery rate can be increased. This process is designed based on the tile (i.e. time) in the said pool (pool tile vertical handoff – PTVHO) which is catalyzed by fuzzy logic to measure the handoff parameters efficiently
. Microwave-assisted solvothermal controlled synthesis of Fe-Co
Syntheses of bimetallic cobalt-iron-based nanoparticles starting from Co(acac)2 and Fe(acac)3 (acac = acetylacetonate) were carried out by microwave-assisted solvothermal process, using ethylene glycol as the solvent and (polyvinylpyrrolidone) PVP, as the stabilizer. Indeed, the reaction mechanism in the presence of ethylene glycol is well understood [1] with the role of PVP being the inhibition of nanoparticles growth [2]. However, the control of the morphology of the synthetized nanoparticles is still a great challenge. Herein, we demonstrated that by adding amines to the reaction mixture, it is possible to control the morphology of the prepared bimetallic cobalt-iron materials. Thus, different Co-Fe micro-composites were synthetized by an innovative microwave assisted solvothermal synthesis, which allows to considerably reduce reaction time from 12 h to 15 min, with respect to classical thermal methods. The procedure was optimized by varying several parameters, such as: amount of PVP, in the presence or in the absence of amines, reaction temperature. The dark brown obtained powders were characterized by scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis, confirming the beneficial effect of the presence of the amine in the morphology of the obtained composites. The obtained results open a new scenario for further studies on the possibility to control the morphology of bimetallic composite materials.
[1] Fievet F, Lagier J P and Figlarz M Mater. Res. Soc. Bull. 24 (1989) 29–34
[2] Teranishi T, Kurita R and Miyake M J. Inorg. Organometall. Polym. 10 (2000) 145–5
Eumelanin Graphene-Like Integration: The Impact on Physical Properties and Electrical Conductivity
The recent development of eumelanin pigment-based blends integrating "classical" organic conducting materials is expanding the scope of eumelanin in bioelectronics. Beyond the achievement of high conductivity level, another major goal lays in the knowledge and feasible control of structure/properties relationship. We systematically investigated different hybrid materials prepared by in situ polymerization of the eumelanin precursor 5,6-dihydroxyindole (DHI) in presence of various amounts of graphene-like layers. Spectroscopic studies performed by solid state nuclear magnetic resonance (ss-NMR), x-ray photoemission, and absorption spectroscopies gave a strong indication of the direct impact that the integration of graphene-like layers into the nascent polymerized DHI-based eumelanin has on the structural organization of the pigment itself, while infrared, and photoemission spectroscopies indicated the occurrence of negligible changes as concerns the chemical units. A tighter packing of the constituent units could represent a strong factor responsible for the observed improved electrical conductivity of the hybrid materials, and could be possible exploited as a tool for electrical conductivity tuning
EFFECT OF LOWER ETHANOL GASOLINE BLENDS ON PERFORMANCE AND EMISSION CHARACTERISTICS OF THE SINGLE CYLINDER SI ENGINE
Alcohols, basically ethanol is considered as a leading alternative fuel for automotive application because of its ability to reduce the air pollution and cost of the fuel. This paper investigates the effect of lower ethanol gasoline blends (up to 20% by volume) on performance and emission characteristics of the single cylinder four stroke SI engine. Tests were carried out for power, torque, fuel consumption and brake mean effective pressure, while exhaust emissions were analyzed for CO, CO2, and HC by using different ethanol gasoline blends on volume basis at wide open throttle and variable engine speed from 4000 to 8000 rpm. Results were compared with the pure gasoline. It showed that as the ethanol content increases the power, torque, fuel consumption, brake mean effective pressure and CO2 emission while reduces HC and CO emission
Sharp change over from compound nuclear fission to shape dependent quasi fission
Fission fragment mass distribution has been measured from the decay of
Bk nucleus populating via two entrance channels with slight difference
in mass asymmetries but belonging on either side of the Businaro Gallone mass
asymmetry parameter. Both the target nuclei were deformed. Near the Coulomb
barrier, at similar excitation energies the width of the fission fragment mass
distribution was found to be drastically different for the N +
Th reaction compared to the B + U reaction. The entrance
channel mass asymmetry was found to affect the fusion process sharply.Comment: 4 pages,6 figure
Ceramic synthesis of disordered lithium rich oxyfluoride materials
Disordered lithium-rich transition metal oxyfluorides with a general formula LiMOF (M being a transition metal) are gaining more attention due to their high specific capacity which can be delivered from the facecentered cubic (fcc) structure. The most common synthesis procedure involves use of mechanosynthesis. In this work, ceramic synthesis of lithium rich iron oxyfluoride and lithium rich titanium oxyfluoride are reported. Two ceramic synthesis routes are developed each leading to the different level of doping with Li and F and different levels of cationic disorder in the structure. Three different LiMOF samples (x ¼ 0.25, 0.3 and 1) are compared with a sample prepared by mechanochemical synthesis and non-doped LiFeO2 with fcc structure. The obtained lithium rich iron oxyfluoride are characterized by use of M€ossbauer spectroscopy, X-ray absorption spectroscopy, NMR and TEM. Successful incorporation of Li and F have been confirmed and specific capacity that can be obtained from the samples is in the correlation with the level of disorder introduced with doping, nevertheless oxidation state of iron in all samples is very similar. Conclusions obtained from lithium rich iron oxyfluoride are validated by lithium rich titanium oxyfluoride
State of malaria diagnostic testing at clinical laboratories in the United States, 2010: a nationwide survey
<p>Abstract</p> <p>Background</p> <p>The diagnosis of malaria can be difficult in non-endemic areas, such as the United States, and delays in diagnosis and errors in treatment occur too often.</p> <p>Methods</p> <p>A nationwide survey of laboratories in the United States and its nine dependent territories was conducted in 2010 to determine factors that may contribute to shortcomings in the diagnosis of malaria. This survey explored the availability of malaria diagnostic tests, techniques used, and reporting practices.</p> <p>Results</p> <p>The survey was completed by 201 participants. Ninety percent reported that their laboratories had at least one type of malaria diagnostic test available on-site. Nearly all of the respondents' laboratories performed thick and thin smears on-site; approximately 50% had access to molecular testing; and only 17% had access to rapid diagnostic tests on-site. Seventy-three percent reported fewer than five confirmed cases of malaria in their laboratory during the 12-month period preceding the survey. Twenty-eight percent stated that results of species identification took more than 24 hours to report. Only five of 149 respondents that performed testing 24 hours a day, 7 days a week complied with all of the Clinical and Laboratory Standards Institute (CLSI) guidelines for analysis and reporting of results.</p> <p>Conclusion</p> <p>Although malaria diagnostic testing services were available to a majority of U.S. laboratories surveyed, very few were in complete compliance with all of the CLSI guidelines for analysis and reporting of results, and most respondents reported very few cases of malaria annually. Laboratories' difficulty in adhering to the rigorous CLSI guidelines and their personnel's lack of practice and proficiency may account for delays and errors in diagnosis. It is recommended that laboratories that infrequently process samples for malaria seek opportunities for practice and proficiency training annually and take advantage of available resources to assist in species identification.</p
Direct observation of the oxygen isotope effect on the in-plane magnetic field penetration depth in optimally doped YBaCuO
We report the first direct observation of the oxygen-isotope
(O/O) effect on the in-plane penetration depth in
a nearly optimally doped YBaCuO film using the novel
low-energy muon-spin rotation technique. Spin polarized low energy muons are
implanted in the film at a known depth beneath the surface and precess in
the local magnetic field . This feature allows us to measure directly the
profile of the magnetic field inside the superconducting film in the
Meissner state and to make a model independent determination of .
A substantial isotope shift % at 4 K is
observed, implying that the in-plane effective supercarrier mass
is oxygen-isotope dependent with .Comment: 4 pages, 2 figure
How calcination affects the morphology and the catalytic activity of polymer supported Nickel
A nickel containing monomer, Ni(AAEMA)2 (AAEMA = deprotonated form of 2-(acetoacetoxy) ethyl methacrylate) was co-polymerized with ethyl methacrylate (co-monomer) and ethylene glycol dimethacrylate (cross-linker) [1]. The obtained polymer was a green methacrylic resin containing Ni(II) centers homogeneously dispersed in the catalyst, which resulted insoluble in all common organic solvents and in water. The material can be described as an amphiphilic resin, air and moisture stable, with the peculiarity to swell in halogenated solvents, acetone and water and to shrink in diethyl ether and petroleum ether. The polymer was calcined under reductive conditions (dihydrogen with initial pressure of 5 bar) following two procedures, differing from each other for the cooling conditions. In the first procedure the calcined material was cooled under dihydrogen gas, while in the second one the cooling step occurred under air. After calcination, the green Ni(II) based co-polymer turned into black resins, Ni-res1 (obtained with hydrogen cooling) and Ni-res2 ((obtained with air cooling). TEM analyses showed that both Ni-res1 and Ni-res2 supported Ni nanoparticles with different morphologies, being the metal nanoparticles onto Ni-res1 smaller than the ones dispersed in Ni-res2, that had an urchin-like shape. Both Ni based co-polymers were tested as catalysts in the reduction of nitrobenzene with NaBH4 [2]. Ni-res1 resulted more active and selective towards aniline, with respect to Ni-res2.
[1] M.M. Dell’Anna, G. Romanazzi, P. Mastrorilli, Curr. Org. Chem. 17 (2013) 1236
[2] A.M. Fiore, G. Romanazzi, M.M. Dell’Anna, M. Latronico, C. Leonelli, A. Rizzuti, M. Mali, P. Mastrorilli, Mol. Catal. 476 (2019) 11050
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