We report detection of severe acute respiratory syndrome coronavirus 2 Omicron variant (B.1.1.529) in an asymptomatic, fully vaccinated traveler in a quarantine hotel in Hong Kong, China. The Omicron ...variant was also detected in a fully vaccinated traveler staying in a room across the corridor from the index patient, suggesting transmission despite strict quarantine precautions.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Environmental concern and availability of petroleum fuels have caused interests in the search for alternate fuels for internal combustion engines. Waste plastics are indispensable materials in the ...modern world and application in the industrial field is continually increasing. In this context, waste plastics are currently receiving renewed interest. As an alternative, non-biodegradable, and renewable fuel, waste plastic oil is receiving increasing attention. The waste plastic oil was compared with the petroleum products and found that it can also be used as fuel in compression ignition engines. In the present work, the influence of injection timing on the performance, emission and combustion characteristics of a single cylinder, four stroke, direct injection diesel engine has been experimentally investigated using waste plastic oil as a fuel. Tests were performed at four injection timings (23°,20°,17° and 14° bTDC). When compared to the standard injection timing of 23° BTDC the retarded injection timing of 14° bTDC resulted in decreased oxides of nitrogen, carbon monoxide and unburned hydrocarbon while the brake thermal efficiency, carbon dioxide and smoke increased under all the test conditions.
We have investigated the femtosecond soliton propagation in inhomogeneous fiber, which is described by the modified inhomogeneous Hirota equation with variable coefficient (MIH-vc). With the aid of ...AKNS method, corresponding Lax pair is constructed. By virtue of the Darboux transformation method and symbolic computation, the analytic one- and two-soliton solutions are explicitly obtained. Using obtained solutions, we graphically discuss the features of femtosecond solitons in modified inhomogeneous Hirota system by changing the profile of variable coefficients. We analyze various form of group velocity dispersion, third order dispersion and nonlinearity parameter for periodic amplification system, exponentially distributed system, parabolic solitons, periodic exponentially modulated system, which will be observable in the future experiments. These results are potentially useful in future experiments and soliton control for long-distance optical communication. Finally, the soliton solutions of the MIH-vc equation in double Wronskian form is constructed and further verified using the Wronskian technique by substitute in bilinear equations.
Under investigation in this paper is an inhomogeneous nonlinear Schrödinger–Maxwell–Bloch system with variable dispersion, nonlinearity and tapered functions which describes the propagation of ...optical pulses in an inhomogeneous erbium-doped tapered fiber. Under certain coefficient constraints, multi-soliton solutions are obtained by the Darboux transformation method and symbolic computation. In order to study the impact of tapering on soliton dynamics in an inhomogeneous erbium-doped periodic distributed amplification system, a specific form of tapered profile is considered.
► Neural bases of greater attentional control in action video game players (VGPs). ► Greater suppression of irrelevant information in VGPs. ► Efficient distractor suppression may contribute to VGPs ...superior attention. ► Lesser recruitment of areas mediating allocation and control of attention in VGPs. ► More automatic and flexible allocation of attentional resources in VGPs.
Over the past few years, the very act of playing action video games has been shown to enhance several different aspects of visual selective attention, yet little is known about the neural mechanisms that mediate such attentional benefits. A review of the aspects of attention enhanced in action game players suggests there are changes in the mechanisms that control attention allocation and its efficiency (Hubert-Wallander, Green, & Bavelier, 2010). The present study used brain imaging to test this hypothesis by comparing attentional network recruitment and distractor processing in action gamers versus non-gamers as attentional demands increased. Moving distractors were found to elicit lesser activation of the visual motion-sensitive area (MT/MST) in gamers as compared to non-gamers, suggestive of a better early filtering of irrelevant information in gamers. As expected, a fronto-parietal network of areas showed greater recruitment as attentional demands increased in non-gamers. In contrast, gamers barely engaged this network as attentional demands increased. This reduced activity in the fronto-parietal network that is hypothesized to control the flexible allocation of top-down attention is compatible with the proposal that action game players may allocate attentional resources more automatically, possibly allowing more efficient early filtering of irrelevant information.
The formation of PrFeO3 perovskite nanocrystalline materials in the orthorhombic phase was achieved via induced exothermic heating process. The Rietveld refinement analysis performed by importing the ...COD database entry: 96-210-7085 in Fullprof program package has revealed that the lattice parameters of synthesized PrFeO3 unit cells are a = 5.479828 Å; b = 5.578260 Å; c = 7.789780 Å. The crystallite size and incoherent diffraction domain induced strain of PrFeO3 are calculated as 28.24 nm and 2.4625 × 10−4 respectively. The vacancy of Pr ion (A side) was found slightly higher than Fe ions (B-side) in the PrFeO3 unit cells. The peaks appearance at 571 cm−1 and 536 cm−1 due to metal oxide vibration in FTIR spectrum were assigned to harmonically vibrating (Fe–O2 and Fe–O5) and (Fe–O1 and Fe–O4) groups respectively and their vibrational frequencies agreed with the theoretically calculated frequencies. It was observed that from the MTZFC curve, rotation of the vector component (along c-axis) of Pr ion magnetic moment takes place below 35.31 K. MH hysteresis curve of prepared sample was characterized by lower magnitude of retentivity and coercivity indicating that the synthesized PrFeO3 materials fall under the category of soft ferromagnets were reported in detail.
•Crystalline nature exhibiting PrFeO3 materials has been achieved by passing 800 wt power supply for 30 s per cycle followed by 12 cycles.•The vacancy of cation Pr3+ at A side was found slightly higher than B side Fe3+ ions in PrFeO3 unit cells.•The synthesized PrFeO3 crystalline materials contain mismatched lattice planes between unit cell clusters due to cation or anion vacancies or impurity atoms and hence Williamson Hall analysis was carried out to reveal the size of crystallites.•Weak ferromagnetism was observed due to lower bond angle of Fe–O–Fe with 147.3026 and 151.8686°.
In this present investigation, an aqueous Basella alba leaves extract was used to synthesize AgNPs. The green synthesis approach is carried out in our work due to non-toxic, less cost, and ...ecofriendly methods. FTIR spectra are used to confirm the biomolecules present in B.alba leaves extract along with AgNPs and these compounds are responsible for Ag particle from micro to nanostructure. The FCC structure and crystalline nature of the AgNPs are analyzed with the help of XRD and TEM techniques respectively. DLS and Zeta potential techniques are carried out to find the size and stability of AgNPs respectively and UV is used to verify the presence of AgNPs in synthesized samples employing SPR peaks around 435 nm. The antioxidant studies expose eminent scavenging activity which ranges from 13.71% to maximum 67.88%. Green synthesized AgNPs possess well organized biological activities concerning antioxidant and antibacterial, which can be used in some biologically applications.
•Biological technique is cost-efficient, capable of processing AgNPs at 60 °C.•Synthesized AgNPs were spherical in size and the size ranging from 18 to 35 nm.•The feasible biomolecules which are liable for the minimization of Ag+ ions.•Alkyl halides bond reported that the indicates association of alkanes.•AgNPs reported that proteins could bind to silver nanoparticles which are compatible.
Increase in energy demand, stringent emission norms and depletion of oil resources have led the researchers to find alternative fuels for internal combustion engines. On the other hand waste plastic ...pose a very serious environment challenge because of their disposal problems all over the world. Plastics have now become indispensable materials in the modern world and application in the industrial field is continually increasing. In this context, waste plastic solid is currently receiving renewed interest. The properties of the oil derived from waste plastics were analyzed and compared with the petroleum products and found that it has properties similar to that of diesel. In the present work, waste plastic oil was used as an alternate fuel in a DI diesel engine without any modification. The present investigation was to study the performance, emission and combustion characteristics of a single cylinder, four-stroke, air-cooled DI diesel engine run with waste plastic oil. The experimental results have showed a stable performance with brake thermal efficiency similar to that of diesel. Carbon dioxide and unburned hydrocarbon were marginally higher than that of the diesel baseline. The toxic gas carbon monoxide emission of waste plastic oil was higher than diesel. Smoke reduced by about 40% to 50% in waste plastic oil at all loads.
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