An approach to detect the secondary arc extinction is proposed here for single-phase auto-reclosing of non-compensated transmission lines. It consists on the analysis of the line side voltage phasors ...in the modal domain to safely and rapidly identify the presence and the extinction of secondary arc in the line. The procedure can also determine the arc re-ignition if it occurs during the line dead time. Since the proposed approach requires only the voltage phasors at one line terminal, it can be easily implemented in existing Intelligent Electronic Devices (IEDs) with no additional hardware or equipment requirement. Data from the Brazilian Power Grid were used to generate the case studies through the Electromagnetic Transients Program (EMTP). Moreover, field recordings were used to validate the proposed approach. A qualitative comparison with existing methods was accomplished and the obtained results reveal the proposed scheme efficiency, reliability and robustness.
Objectives
Ameloblastoma is an odontogenic epithelial tumour with a low expression of mismatch repair system components. We aimed to investigate the methylation status of the genes MSH2, MSH3 and ...MSH6 (MutS group) in conventional ameloblastomas.
Materials and Methods
The ameloblastoma and dental follicle samples (n = 10 each) were collected from 20 different patients. Each ameloblastoma sample was sectioned into two fragments: one was paraffin‐embedded while the other one, likewise the dental follicle samples, was fixed in RNAlater and frozen at −196°C. All frozen samples were investigated for the MutS genes methylation levels, using the enzymatic restriction digestion and quantitative real‐time PCR (qPCR) assay. The ameloblastoma paraffin‐embedded samples were submitted to immunohistochemical reactions for MutS proteins detection and digitally quantification. Correlation analyses were performed between the immunohistochemical results and the respective gene methylation percentage.
Results
There are no significant differences between the MutS genes methylation levels in the ameloblastoma and the dental follicle. However, a strong negative correlation was found between MSH2 and MSH6 gene methylation status and their respective proteins expressions evaluated by immunohistochemistry.
Conclusion
Our results show that the genes methylations is in part responsible for decreasing the expression of MSH2 and MSH6 genes in ameloblastoma.
Summary
This study established a protocol to purify Toxoplasma gondii tachyzoite microvesicles and exosomes, called as extracellular vesicles (EVs). In addition, the investigations were conducted to ...determine the kinetic of EV release by tachyzoites and whether EV proteins are able to modulate the host immune response. The particle size and concentration released by tachyzoites in culture medium at different incubation‐period were characterized by nanoparticle tracking analysis. Tachyzoites (1 × 106) released around 4.37 ± 0.81 × 108 EVs/mL/h, with size varying between 138.2 and 171.9 nm. EVs released into the medium were purified by gel‐exclusion chromatography and screened by ELISA, using a pool of human positive sera for toxoplasmosis. EV‐fractions contained high concentration of proteins, and EVs were analyzed by scanning and transmission electron microscopies. Tachyzoites released EVs into the culture medium throughout all membrane surface, and these vesicles contain small RNAs/miRNA. Pooled sera from chronically infected human or mice (infected with 2 different T. gondii strains) recognized distinct EV electrophoretic patterns in immunoblotting. T. gondii EVs significantly induced IL‐10, TNF‐α and iNOS in murine macrophages. In conclusion, this study shows that T. gondii secrete/excrete EVs (microvesicles and exosomes) contain miRNA and they were immunologically recognized by host immune response.
This paper presents a practical methodology for traveling wave (TW)-based fault location on homogeneous transmission lines. It provides improvements in the fault location accuracy in real-world ...scenarios by eliminating the influence of uncertainties in line parameters and data time synchronization errors, which are potentialities not readily available in actual micro-processed fault location devices. A commercially available software for TW analysis is proposed to be used as a support tool to compute auxiliary variables, from which the accurate fault distance is estimated. Real and simulated TW fault records are assessed, from which the proposed fault location procedure is evaluated, highlighting its step by step. The obtained results show that the proposed methodology is straightforward and reliable, being quite useful for field applications.
Trypanosoma cruzi, the aetiologic agent of Chagas disease, releases vesicles containing a wide range of surface molecules known to affect the host immunological responses and the cellular ...infectivity. Here, we compared the secretome of two distinct strains (Y and YuYu) of T. cruzi, which were previously shown to differentially modulate host innate and acquired immune responses. Tissue culture-derived trypomastigotes of both strains secreted extracellular vesicles (EVs), as demonstrated by electron scanning microscopy. EVs were purified by exclusion chromatography or ultracentrifugation and quantitated using nanoparticle tracking analysis. Trypomastigotes from YuYu strain released higher number of EVs than those from Y strain, enriched with virulence factors trans-sialidase (TS) and cruzipain. Proteomic analysis confirmed the increased abundance of proteins coded by the TS gene family, mucin-like glycoproteins, and some typical exosomal proteins in the YuYu strain, which also showed considerable differences between purified EVs and vesicle-free fraction as compared to the Y strain. To evaluate whether such differences were related to parasite infectivity, J774 macrophages and LLC-MK2 kidney cells were preincubated with purified EVs from both strains and then infected with Y strain trypomastigotes. EVs released by YuYu strain caused a lower infection but higher intracellular proliferation in J774 macrophages than EVs from Y strain. In contrast, YuYu strain-derived EVs caused higher infection of LLC-MK2 cells than Y strain-derived EVs. In conclusion, quantitative and qualitative differences in EVs and secreted proteins from different T. cruzi strains may correlate with infectivity/virulence during the host-parasite interaction.
Time-domain protection relays have increasingly attracted the attention of electrical power utilities. These relays speed up the tripping process of traditional protection schemes, increasing the ...stability margins of high-loaded power grids. Among the existing time-domain protection functions, the travelling wave (TW)-based differential protection TW87 has shown to be promising. However, as such a function is relatively new in the relay market, studies on the TW87 performance have been of interest to protection engineers. Thus, this study presents a parametric analysis of the TW87 performance. To do so, massive fault simulations are carried out, considering different fault scenarios and protection settings. From the obtained results, important issues related to the TW87 performance are addressed.
Single-phase auto-reclosing (SPAR) is used in power systems worldwide. However, many SPAR methods do not present a practical approach for field implementation. Although manufacturers have embedded ...SPAR functions into their commercial relays, the closed solutions make not trivial the application of new functions/methods. Thus, in this paper, a practical approach is proposed to leverage existing relays structure aiming to improve SPAR applications. A simple and effective phasor-based single-phase auto-reclosing scheme for non-compensated transmission lines is embedded in a commercially available relay equipped with a free-form programming logic. Field recordings of single-line-to-ground (SLG) faults followed by single-phase opening of transmission lines are used in a playback test procedure for validation. The results attest the effectiveness of the implemented SPAR method, as well as the feasibility of the proposed practical approach for real-world applications.
•A practical approach for single-phase auto-reclosing (SPAR) is addressed here.•A phasor-based SPAR scheme is embedded leveraging an existing relay structure.•A secondary arc extinction detection function is also successfully addressed.•Field recordings are used to attest the effectiveness of the proposed approach.•The presented practical approach can help utilities better exploit the SPAR benefit.
This paper investigates the effects of communication channel latency (CCHL) on time-domain line protection functions. The Alternative Transients Program (ATP) was used to simulate the monitored power ...system and to model both the analyzed relays and communication channels via MODELS language. By doing so, the need for extra long optical fibers for laboratory tests is overcome. To provide a reliable investigation on the CCHL effects, a time-domain relay model is firstly implemented and validated by comparing its response against an actual device. Then, the communication channel is set to properly represent practical CCHL values under different fault scenarios for transmission lines with different lengths. The obtained results show that including the CCHL effects on time-domain protection testing procedures is of utmost importance because, depending on the data propagation time through the communication channel, it may have a relevant influence in what we call here “race of protection functions”.
•Communication channel latency (CCHL) effects on time-domain protection functions tripping times.•CCHL have been disregarded in EMTP relay models.•Which time-domain protection function is fastest when CCHL is considered.•An ATP/MODELS relay model validated with an actual relay.•Race of time-domain protection functions.
Purpose: Development of an application for determining the technical and economic feasibility of implementing and operating domestic biodigesters using rigorous mathematical modeling of the anaerobic ...digestion process in conjunction with Machine Learning techniques to obtain reduced metamodels. Theoretical Framework: The generation of biodegradable waste results from human activities and has detrimental environmental impacts. To mitigate this problem, anaerobic digestion in biodigesters emerges as a viable solution, promoting the production of biogas and biofertilizers, generating economic and environmental benefits. However, implementing and operating this system requires significant investments. Method/Design/Approach: The combination of the ADM1 model with Machine Learning techniques is used to create simplified metamodels, allowing for more feasible simulations and optimizations, thereby developing an application to assess the technical and economic feasibility of biodigesters. This application is obtained by packaging the reduced metamodel using the MATLAB Compiler, which will be made available as an Excel add-in. Results and Conclusion: The reduced metamodel effectively represented the rigorous Simulink model, and the optimization of the process proved satisfactory. Furthermore, the add-in generated through the MATLAB Compiler met expectations. Research Implications: Enhanced understanding of the waste biodigestion process, demonstrating the economic and environmental returns achieved when focusing more on this area. Originality/Value: Development of a tool that enables the simulation and evaluation of a biodigestion process without the need to purchase expensive software.
Purpose: This study aims to determine the economic and technical feasibility of operating and leasing sewage treatment plants through an application that uses mathematical modeling and Machine ...Learning techniques for process optimization. Theoretical Framework: Efficient operation of sewage treatment plants (STPs) is crucial to ensure water quality, minimize environmental impacts, and optimize costs. This study explores how Machine Learning (ML) can model and optimize sewage treatment processes, adapting to real-time conditions. Method/Design/Approach: The BSM1 model is combined with Machine Learning techniques to create simplified metamodels, enabling optimized results and the development of an application for evaluating economic and technical outcomes. Results and Conclusion: The reduced metamodel successfully reproduced the Simulink model, achieving satisfactory optimization. Research Implications: This research benefits water quality improvement, cost reduction, sustainability, innovation, water resource management, awareness, and resilience to extreme weather events, as well as influencing informed policies. Originality/Value: Efficiency, sustainability, economy, and quality of life are core values in this research, benefiting society, the environment, and the economy.
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