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Power system restoration is an important task for system operators. Therefore, much research has been carried out to optimize restoration process, among which, recognition and access to the network skeleton during restoration has been considered as a dominant approach. If the main skeleton-network is recognized appropriately, then reconfiguration and restoring major parts of the network can be performed at the shortest possible time. Restructuring in power industry has introduced new challenges to power system. While, restructuring has affected power system operation seriously, little attention has been paid to restoration process as an extra ordinary mode of system operation in a market based environment. One approach for restoration problem is based on performance indices introduced to rank nodes of the network. In this paper, a new method based on a comprehensive ranking index for electrification of network buses during restoration process is proposed which results in reduction of both the interruption cost and restoration cost. In our ranking approach, both the network configuration and the value of lost load at different buses of the network have been considered in a market based operated system. In the method, the dominant network skeleton for restoration is distinguished such that the restoration time for the rest of network from this skeleton network will be reduced. Our simulation results confirm the validity and efficacy of our proposed approach in different situations, especially in a market-based environment. We have used the Genetic Algorithm (GA) to solve the optimization problem. The method has been tested on IEEE 30-bus network. Results show that this method in compare with similar methods has a better performance. [ABSTRACT FROM AUTHOR]

Multiple-input multiple-output (MIMO) system using orthogonal frequency division multiplexing (OFDM) technique has become a promising method for reliable high data-rate wireless transmission system in which the channel is dispersive in both time and frequency domains. Due to multiple cochannel interferences in a MIMO system, the accuracy of channel estimation is a vital factor for proper receiver design in order to realize the full potential performance of the MIMO-OFDM system. A robust and improved channel estimation algorithm is proposed in this paper for MIMO-OFDM systems based on the least squares (LS) algorithm. The proposed algorithm, called improved LS (ILS), employs the noise correlation in order to reduce the variance of the LS estimation error by estimating and suppressing the noise in signal subspace. The performance of the ILS channel estimation algorithm is robust to the number of antennas in transmit and receive sides. The new algorithm attains a significant improvement in performance in comparison with that of the regular LS estimator. Also, with respect to mean square error criterion and without using channel statistics, the ILS algorithm achieves a performance very close to that of the minimum mean square error (MMSE) estimator in terms of the parameters used in practical MIMO-OFDM systems. A modification of the ILS algorithm, called modified ILS (MILS), is proposed based on using the second order statistical parameters of channel. Analytically, it is shown that the MILS estimator achieves the exact performance of the MMSE estimator. Due to no specific data sequences being required to perform the estimation, in addition to the training mode, the proposed channel estimation algorithms can also be extended and used in the tracking mode with decision-aided method. [ABSTRACT FROM PUBLISHER]

Two different microstructures, i.e., fine-grained solute depleted (FGSD) and coarse-grained solute enriched (CGSE), are prepared by thermomechanical processing. The samples are subjected to six pass equal channel angular pressing (ECAP). EBSD indicates formation of an ultrafine grained (UFG) structure within a size range of 632 nm in FGSD in comparison to 727 nm in CGSE which is attributed to more significant grain fragmentation in the FGSD sample with higher surface area of boundaries. In both as-annealed and -deformed conditions, hardness, yield strength (YS) and ultimate tensile strength (UTS) of the CGSE samples are higher than those of FGSD which is attributed to more significant solute enrichment. Elongation is found to reduce by the initial passes of ECAP and gradually improve by further processing. At a similar deformation history, the uniform elongation of the deformed CGSE samples is higher than those of the deformed FGSD samples which is attributed to more significant solute enrichment and work hardening causing a delayed necking and larger uniform elongation. However, the elongation to failure of FGSD samples after 2, 4 or 6 pass ECAP is larger than the CGSE sample with a similar deformation history which may be due to the high capacity of boundaries to accommodate dislocations and postpone fracture. [ABSTRACT FROM AUTHOR]

Importance: Saprophytic fungi can cause nosocomial infections in high-risk patients. These infections are related to high mortality and cost. In the current study, different species of filamentous fungi and yeast were isolated from the environment of the studied hospitals. Some species were resistant to antifungal drugs. We suggest that the future work concentrates on the relationship between the level/quantification of saprophytic contamination in the environment of hospitals and fungal infections in patients., Competing Interests: The authors declare no conflict of interest.

Background: Dermatophytes have the ability to invade the keratin layer of humans and cause infections. The aims of this study were the accurate identification of dermatophytes by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism method and sequencing and comparison between the in vitro activities of newer and established antifungal agents against them., Methods: Clinical specimens of patients from five Iranian university laboratories were entered in this study. Samples were cultured on sabouraud dextrose agar medium. For molecular identification, extracted DNAs were amplified by the universal fungal primers ITS1 and ITS4, and digested with MvaI enzymes. The antifungal susceptibility test for each isolate to terbinafine, griseofulvin, caspofungin, fluconazole, itraconazole, luliconazole, and isavuconazole was performed, according to the microdilution CLSI M38-A2 and CLSI M61 standard methods., Results: Two hundred and seven fungi species similar to dermatophytes were isolated of which 198 (95.6%) were dermatophytes by molecular assay. The most commonly isolated were Trichophyton mentagrophytes (76/198), followed by Trichophyton interdigitale (57/198), Trichophyton rubrum (34/198), Trichophyton tonsurans (12/198), Microsporum canis (10/198), Trichophyton simii (3/198), Epidermophyton floccosum (3/198), Trichophyton violaceum (2/198), and Trichophyton benhamiae (1/198). The GM MIC and MIC 90 values for all the isolates were as follows: terbinafine (0.091 and 1 μg/ml), griseofulvin (1.01 and 4 μg/ml), caspofungin (0.06 and 4 μg/ml), fluconazole (16.52 and 32 μg/ml), itraconazole (0.861 and 8 μg/ml), isavuconazole (0.074 and 2 μg/ml), and luliconazole (0.018 and 0.25 μg/ml)., Conclusion: Trichophyton mentagrophytes, Trichophyton interdigitale, and Trichophyton rubrum were the most common fungal species isolated from the patients. luliconazole, terbinafine, and isavuconazole in vitro were revealed to be the most effective antifungal agents against all dermatophyte isolates., (© 2023. The Author(s).)

A new strategy is proposed to modify the grain structure and crystallographic texture of laser-powder bed fusion AlSi10Mg alloy using multi-pass friction stir processing (FSP). Accordingly, 1-3 passes of FSP with 100% overlap were performed. Scanning electron microscopy and electron backscattered diffraction were used for microstructural characterization. Continuous dynamic recrystallization and geometric dynamic recrystallization are the governing mechanisms of grain refinement during FSP. The stir zones have bimodal grain structures containing large and fine grains. The multi-pass FSP caused a considerable increase in the volume fraction of the large-grained area in the stir zone, which contained higher values of low-angle boundaries and sharp shear texture components of B(11¯2)[110] and B¯(1¯12¯)[1¯1¯0]. The formation of low-energy grain boundaries in the stir zone and alignment of the low-energy crystallographic planes with the surface of the sample made the strategy of using multi-pass FSP a promising candidate for corrosion resistance enhancement in future studies. Moreover, the detailed evolution of the grains, texture components, grain boundaries, and Si particles is discussed.