Soil moisture ( SM ) is crucial for the Earth's ecosystem, impacting climate and vegetation health. Obtaining in situ observations of SM is labor-intensive and complex, particularly in remote and ...densely vegetated regions like the Amazon rainforest. NASA's soil moisture active and passive (SMAP) mission, utilizing an L-band radiometer, aims to monitor global SM . While it has been validated in areas with low vegetation water content ( VWC ) (< 5 <inline-formula><tex-math notation="LaTeX">{\text{kgm}}^{ - 2}</tex-math></inline-formula>), its efficiency in the Amazon, with dense canopies and high VWC (> 10 <inline-formula><tex-math notation="LaTeX">{\text{kgm}}^{ - 2}</tex-math></inline-formula>), is limitedly investigated due to scarce in situ measurements. This study assessed and analyzed the SMAP SM retrievals in the Amazon, employing the single-channel algorithm and adjusting vegetation optical depth (τ) and single scattering albedo (ω), two key vegetation parameters. It incorporated in situ SM observations from three old-growth rainforest locations: Tambopata (Southwest Amazon), Manaus (Central Amazon), and Caxiuana (Eastern Amazon). The SMAP SM deviated substantially from the in situ SM . However, calibrating τ and ω values, characterized by a lower τ, resulted in better agreement with the in situ measurements. This study emphasizes the pressing need for innovative methodologies to accurately retrieve SM in high- VWC regions like the Amazon rainforest using SMAP data.
Chromium and its oxides have been playing a vital role in the fabrication of micro- and nano-scale structures in numerous applications for several decades. Controllable, robust and anisotropically ...dry-etched hard masks and their optimal etch recipes are required in state-of-the-art device fabrication techniques. In terms of manufacturability and repeatability, a mechanistic understanding of the plasma-etching process of chromium oxide (Cr 2 O 3 ) is necessary for its adoption as a hard mask. We present a systematic investigation of plasma etching of chromium oxide films via an inductively coupled plasma-reactive ion etching (ICP-RIE) system in nanoscale. The effects of plasma composition, ICP source power and HF platen power on the etch rate, sidewall profile, surface morphology, and dc-bias have been methodically investigated. We paid particular attention to studying how oxygen content can be used to control the etch profile of nano trenches using chlorine/oxygen gas mixtures, including extremes of very low and very high oxygen content. It was found that chromium oxide etch mechanisms are dependent strongly on the oxygen level. We achieved desirable vertical sidewalls with reasonable etch rates when the oxygen content is in the range 10-40% in the plasma. Oxygen content below 10% resulted in positively tapered etch profiles with low etch rates. On the other hand, bowl-like etch profiles with undercut formation was observed at high oxygen content above 40%, caused by re-emission of the reactive species at this regime. As a hard mask material, patterning Cr 2 O 3 films compared to Cr metal is advantageous in terms of etch uniformity and reproducibility. Contrary to Cr, Cr 2 O 3 is not as sensitive to chamber wall conditions.
This article concentrates on the model-based fuzzy <inline-formula><tex-math notation="LaTeX">l_{2}-l_{\infty }</tex-math></inline-formula> filtering problem of a discrete-time semi-Markov jump ...nonlinear system. The random jumps in the studied system are governed by the discrete-time semi-Markov process. Therefore, the storage characteristics of the transition probability between systems are fully considered. To analyze the <inline-formula><tex-math notation="LaTeX">\sigma</tex-math></inline-formula>-mean-square stability of the filtering error system, a mode-dependent filter, which is based on the discrete-time fuzzy semi-Markov jump model, is constructed to estimate the state of the system. Thereafter, based on the Lyapunov stability theory and the discrete-time semi-Markov kernel concept, a set of sufficient criteria to ensure the <inline-formula><tex-math notation="LaTeX">\sigma</tex-math></inline-formula>-mean-square stability and <inline-formula><tex-math notation="LaTeX">l_{2}-l_{\infty }</tex-math></inline-formula> performance are derived. In addition, by using the Takagi-Sugeno fuzzy model, the nonlinear problem is effectively solved. Two illustrative examples, including a numerical example and a tunnel diode circuit example, are demonstrated to reveal the practicability of the developed filtering strategy.
As NO x and SO x have significant environmental impacts, advanced treatments are required to remove them from the exhaust gas of a glass melting furnace. Here, we investigate a plasma-chemical hybrid ...process (PCHP) for this purpose. A pilot-scale experiment of the simultaneous removal of NO x and SO x using a PCHP combined with the existing semi-dry type desulfurization reactor is conducted on actual high-temperature exhaust gas from a glass melting furnace. NO (the majority of NO x exist as NO) in the exhaust gas is oxidized to NO 2 using active oxygen (ozone: O 3 ) generated by a plasma ozonizer. The exhaust gas must be cooled to less than 150 °C in order to suppress the thermal decomposition of O 3 , while the gas temperature at the outlet of the semi-dry reactor must be kept at 200-;250 °C to protect the dry-type electrostatic precipitator. Therefore, it is important to form a local cooling area for NO oxidation in the reactor. In this article, we use the three-fluid nozzles of O 3 , water, and air to form the local cooling area and effectively oxidize NO to NO 2 . In addition, we spray NaOH aqueous solution for SO 2 absorption downstream of the NO oxidation area to allow sufficient time for NO oxidation. The SO 2 reacts with NaOH to produce Na 2 SO 3 , a powerful reducing agent. Subsequently, NO 2 reacts with Na 2 SO 3 and is reduced to N 2 , and the Na 2 SO 4 generated in this reaction is reused as a clarifier of the raw materials for glass manufacturing. As a result, the ratio of the amount of removed NO and NO x to the amount of injected O 3 (de-NO/O 3 and de-NO x /O 3 ) is 64% and 78%, respectively; therefore, high efficiency is obtained. This article includes actual examples of the treatment of exhaust gas in a glass melting furnace, using PCHP de-SO x and de-NO x technologies along with results from pilot-scale experiments.
CTL-Based Adaptive Service Composition in Edge Networks Zhao, Deng; Zhou, Zhangbing; Hung, Patrick C. K. ...
IEEE transactions on services computing,
2023-March-April-1, 2023-3-1, 2023-03-01, Letnik:
16, Številka:
2
Journal Article
Recenzirano
With the recent adoption of edge computing, I nternet of T hings ( IoT ) devices collaborate at the network edge to facilitate edge-native applications. In this setting, IoT devices are typically ...encapsulated as IoT services to encode their functionalities, and their collaboration is achieved through IoT service composition. Due to the continuous resource occupancy, release, and consumption of IoT devices at runtime, a composition, which is functionally compatible and non-functionally optimal at this moment, may not hold in the forthcoming time durations, when certain IoT services may significantly downgrade in their Q uality-of- S ervices ( QoS ). To guarantee the compatibility of compositions with QoS variations, this article proposes an adaptive composition mechanism leveraging C omputation T ree L ogic ( CTL ) specifications. Specifically, we formalize the composition as a temporal task, and convert it to CTL formulae with the abstractions of required functionalities and composite structures. Functional compatibility is formally interpreted by CTL semantics during the execution of compositions. Besides, we construct a QoS D ependency G raph ( QoSDG ) to capture QoS variations, and achieve adaptive composition with dynamic QoS satisfactions. Extensive experiments are conducted upon publicly-available datasets, and comparison results demonstrate that our technique outperforms the state-of-the-art counterparts in heterogenous scenarios with higher QoS dependencies ranging from 0.3<inline-formula><tex-math notation="LaTeX">\%</tex-math> <mml:math><mml:mo>%</mml:mo></mml:math><inline-graphic xlink:href="zhou-ieq1-3184013.gif"/> </inline-formula> to 27.8<inline-formula><tex-math notation="LaTeX">\%</tex-math> <mml:math><mml:mo>%</mml:mo></mml:math><inline-graphic xlink:href="zhou-ieq2-3184013.gif"/> </inline-formula>.
In our ongoing study, we explore the concepts of I3-Cauchy and I3-Cauchy for triple sequences in the context of random 2-normed spaces (RTNS). Moreover, we introduce and analyze the notions of ...I3-convergence, I3-convergence, I3-limit points, and I3-cluster points for random 2-normed triple sequences. Significantly, we establish a notable finding that elucidates the connection between I3-convergence and I3-convergence within the framework of random 2-normed spaces, highlighting their interrelation. Additionally, we provide an illuminating example that demonstrates how I3-convergence in a random 2-normed space might not necessarily imply I3-convergence. Our observations underscore the importance of condition (AP3) when examining summability using ideals. Furthermore, we thoroughly investigate the relationship between the properties (AP) and (AP3), illustrating through an example how the latter represents a less strict condition compared to the former.
Modeling high temperature superconductor (HTS) motors remains challenging mainly due to the high aspect ratio of these conductors but also because of the properties of the magnetic materials. This ...article presents a 2-D time dependent model to assess the ac losses of superconducting motors based on the new T-A -formulation, which by using the finite-element method, allows its implementation in commercial software. The T-A -formulation computes the magnetic flux density with different Maxwell's equations depending on the areas of the motor and makes it possible to use the thin strip approximation i.e., the HTS tapes are modeled as infinitely thin lines. The model is then expected to tackle the high aspect ratio of the HTS as well as decreasing both the mesh complexity and the computing time. The first objective of the article is to validate the method in 2-D by evaluating the ac losses of a specific synchronous motor called superconducting torque motor; the computed results are compared with good agreements to those assessed with the minimum electromagnetic entropy production method, already validated. In a second part, the same losses are computed, taking into account the field anisotropy of <inline-formula><tex-math notation="LaTeX">J_{c}</tex-math></inline-formula> with the implementation of a dataset based on experimentally measured <inline-formula><tex-math notation="LaTeX">I_{c}</tex-math></inline-formula> at 65 and 77 K. With the model proposed in this article, it is possible to calculate the magnetic field of a whole electrical machine cross section and compute the ac losses in the individual tapes of its windings within the same numerical model.
Photodetectors based on two-dimensional materials exhibit excellent performance including high specific detectivity and fast response times. However, the polarization detection performance remains to ...be improved. Here, we propose a strategy to improve the polarization sensitivity of TlPt 2 S 3 -based photodetectors by defect engineering based on density functional theory (DFT) calculations and investigate their optoelectronic properties using quantum transport simulations at 0.2 V bias. Theoretical calculations show that the monolayer TlPt 2 S 3 achieves a multifunctional output of the optoelectronic device and obtains a larger photocurrent and high extinction ratio by defect engineering under linearly polarized light irradiation. These results indicate that TlPt 2 S 3 is expected to be one of the candidate materials for future optoelectronics and polarized light devices.
Minimizing electrical losses at metal/silicon interfaces in high-efficiency single-junction silicon solar cells requires the use of carrier-selective passivating contacts. The electronic barrier ...heights at the insulator/silicon interface are necessary for calculating the probability of quantum tunneling of charge carriers at these interfaces. Thus, precise knowledge of these parameters is crucial for the development of contact schemes. Using a photoemission-based method, we experimentally determine the electronic band offsets of Al 2 O 3 , HfO 2 and SiO 2 layers grown by atomic layer deposition (ALD) on silicon. For Al 2 O 3 /Si, we determine a valence band offset (Δ E V ) and conduction band offset (Δ E C ) of 3.29 ± 0.07 eV and 2.24 ± 0.13 eV, respectively. For HfO 2 /Si, Δ E V and Δ E C are determined as 2.67 ± 0.07 eV and 1.81 ± 0.21 eV, while for SiO 2 /Si, Δ E V and Δ E C are 4.87 ± 0.07 eV and 2.61 ± 0.12 eV, respectively. Using technology computer-aided design simulations, we incorporate our experimental results to estimate the contact resistivity that would be attained at various dielectric layer thicknesses. We find that for achieving the 100 mΩ·cm 2 contact resistivity benchmark, Al 2 O 3 layers should be no thicker than 1.65 nm for a p -type polysilicon-based hole-selective contact, assuming hole tunneling masses taken from the literature. Correspondingly, for HfO 2 and SiO 2 , an upper limit of 1.4 nm is determined as the thickness threshold in order to utilize these ALD-grown layers for contacts in high-performance silicon photovoltaics.
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