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The book on "Analog and Digital Electronic Circuits and its Applications - Mastering the Foundations" covers a wide range of topics related to the principles and applications of electronic circuits and systems. Analog electronics deals with continuous signals and the behavior of components such as resistors, capacitors, and operational amplifiers. It focuses on the precise representation and manipulation of realworld signals. On the other hand, digital electronics involves the processing and transmission of discrete, binary signals, using components such as logic gates, flip-flops, and microcontrollers. It encompasses the design and implementation of digital systems, including computers, communication systems, and control systems. Understanding analog and digital electronics is essential for anyone interested in the field of electronics and its wide-ranging applications in various industries.

Superconductivity has been observed in moiré systems such as twisted bilayer graphene, which host flat, dispersionless electronic bands. In parallel, theory work has discovered that superconductivity and superfluidity of flat-band systems can be made possible by the quantum geometry and topology of the band structure. These recent key developments are merging into a flourishing research topic: understanding the possible connection and ramifications of quantum geometry on the induced superconductivity and superfluidity in moiré multilayer and other flat-band systems. This article presents an introduction to how quantum geometry governs superconductivity and superfluidity in platforms including, and beyond, graphene. Ultracold gases are introduced as a complementary platform for quantum geometric effects and a comparison is made to moiré materials. An outlook sketches the prospects of twisted multilayer systems in providing the route to room-temperature superconductivity.

Insulator self-blasts, cracked insulators, and bird nests often lead to large-scale power outages and safety accidents, while the detection system based on a single UAV and YOLOv7 is difficult to meet the speed and accuracy requirements in actual detection. Therefore, a novel insulator defect detection method based on improved YOLOv7 and a multi-UAV collaborative system is proposed innovatively. Firstly, a complete insulator defects dataset is constructed, and the introduction of insulator self-blasts, cracked insulators, and bird nest images avoids the problem of low reliability for single defect detection. Secondly, a multi-UAV collaborative platform is proposed, which improves the search scope and efficiency. Most critically, an improved YOLOv7-C3C2-GAM is proposed. The introduction of the C3C2 module and the CNeB2 structure improves the efficiency and accuracy of feature extraction, and the introduction of a global attention mechanism (GAM) improved the feature extraction ability to extract key information about small targets or occluded targets and feature in the region of interest. Compared with YOLOv7, the accuracies of YOLOv7-C3C2 and YOLOv7-C3C2-GAM are improved by 1.3% and 0.5%, respectively, the speed of YOLOv7-C3C2 is improved by 0.1 ms, and the lightweight sizes are reduced by 8.2 Mb and 8.1 Mb, respectively. Therefore, the proposed method provides theoretical and technical support for power equipment defect detection.

Flashover at gas/insulator interface acts as a vital challenge to the safe and stable operation of gas-insulated system especially when involved with surface metallic particle. In this paper, flashover characteristics at SF6/epoxy insulator interface were investigated concerning on the tracking property based on image analysis. DC flashover experiments were operated for basin-type spacer with metallic particle at various locations. Flashover voltage was obtained and tracking on the surface after successive flashover was captured. Improved image analysis method based on fractal theory was carried out to evaluate tracking pattern quantitatively. The relation between the fractal dimension of tracking and field distribution at particle tip was revealed. Obtained results showed that flashover voltage decreased due to severe field distortion with moving particle from ground to HV electrode. Meanwhile, fractal dimension of tracking covering the area from particle to ground electrode indicated centralized tendency. Simulation result confirmed this variation as the consequence of centralized field distribution at the tip of particle. The quantitative relation between fractal dimension and field distribution suggests new sight to estimate the influence of metallic particle on insulation property in the gas-insulated system.

Edge computing can avoid the long-distance transmission of massive data and problems with large-scale centralized processing. Hence, defect identification for insulators with object detection models based on deep learning is gradually shifting from cloud servers to edge computing devices. Therefore, we propose a detection model for insulators and defects designed to deploy on edge computing devices. The proposed model is improved on the basis of YOLOv4-tiny, which is suitable for edge computing devices, and the detection accuracy of the model is improved on the premise of maintaining a high detection speed. First, in the neck network, the inverted residual module is introduced to perform feature fusion to improve the positioning ability of the insulators. Then, a high-resolution detection output head is added to the original model to enhance its ability to detect defects. Finally, the prediction boxes are post-processed to incorporate split object boxes for large-scale insulators. In an experimental evaluation, the proposed model achieved an mAP of 96.22% with a detection speed of 10.398 frames per second (FPS) on an edge computing device, which basically meets the requirements of insulator and defect detection scenarios in edge computing devices.

The failure of insulators may seriously threaten the safe operation of the power system, where the state detection of high-voltage insulators is a must for the normal and safe operation of the power system. Based on the data of insulators in aerial images, this work explored an enhanced particle swarm algorithm to optimize the parameters of the support vector machine. A support vector machine model was therefore established for the identification of the normal and defective states of the insulators. This methodology works with the structure minimization principle of SVM and the characteristics of particle swarm fast optimization. First, the aerial insulator image was segmented as a target by way of the seed region growth based on double-layer cascade morphological improvements, and then, HOG features plus GLCM features were extracted as sample data. Finally, an ameliorated PSO-SVM classifier was designed to realize insulator state identification. Comparisons were made between PSO-SVM and conventional machine learning algorithms, SVM and Random Forest, and an optimization algorithm, Gray Wolf Optimization Support Vector Machine (GWO-SVM), and advanced neural network CNN. The experimental results showed that the performance of the algorithm proposed in this paper touched the top level, where the recognition accuracy rate was 92.11%, the precision rate 90%, the recall rate 94.74%, and the F1-score 92.31%.

Excessive rise in energy consumption has been one of the major predicaments of recent decades. Among all the sectors, residential buildings are one of the main consumers of energy resources. Because air conditioning systems are the main ground for using energy inside houses, researchers have proposed diverse methods of reducing energy loss such as encapsulating insulators in wall structures. In this paper, the main focus is to calculate and then optimize the total heating and cooling loads as well as the total costs. The building model was simulated in cities with different climatic situations using EnergyPlus software. For optimization, five design variables were determined and 300 Design of Experiment points were considered for each city to measure the Objective Functions, which are the building’s total load and cost. To find the optimal states, Response Surface Methodology (RSM) is utilized to predict continuous functions from discrete data of experiments. Consequently, total load and total costs of building in various climatic conditions were improved by a range of 2%–16%, and the Static Payback Period and Human Heating Comfort were ameliorated dramatically.

To realize the accurate identification and segmentation of the insulator string in the complex background image with diverse appearance and obscuration, this paper proposes an insulator segmentation method based on improved U-Net. The algorithm embeds the attention mechanism ECA-Net (Efficient Channel Attention Neural Networks) in the coding stage of U-Net to improve the model’s ability to extract semantic features, thereby improving the accuracy of insulator detection. Experimental results show that the average overlap IOU of the proposed method is 96.8%, which can more accurately segment different types of insulators in complex backgrounds.

Aiming at the problem that the detection and damage recognition algorithm of insulator aerial images is difficult to be applied to the embedded platform, this paper proposed an improved Tiny-YOLOv4 lightweight target detection network algorithm. This algorithm combined the Self-Attention mechanism and ECA-Net (Efficient Channel Attention Neural Networks), which could greatly reduce the complexity of the original YOLOv4 algorithm, and the model size is 24.9 MB. Under the condition of ensuring the detection accuracy (>91%), the detection speed is as high as 94FPS. It is transplanted to the Jetson Xavier NX embedded platform, and the average detection speed reaches 22FPS, which effectively meets the real-time detection requirements in the power inspection.

Binding sites of the chromatin regulator protein CTCF function as important landmarks in the human genome. The recently characterized CTCF-binding sites at LINE-1 repeats depend on another repeat-regulatory protein CGGBP1. These CGGBP1-dependent CTCF-binding sites serve as potential barrier elements for epigenetic marks such as H3K9me3. Such CTCF-binding sites are associated with asymmetric H3K9me3 levels as well as RNA levels in their flanks. The functions of these CGGBP1-dependent CTCF-binding sites remain unknown. By performing targeted studies on candidate CGGBP1-dependent CTCF-binding sites cloned in an SV40 promoter-enhancer episomal system we show that these regions act as inhibitors of ectopic transcription from the SV40 promoter. CGGBP1-dependent CTCF-binding sites that recapitulate their genomic function of loss of CTCF binding upon CGGBP1 depletion and H3K9me3 asymmetry in immediate flanks are also the ones that show the strongest inhibition of ectopic transcription. By performing a series of strand-specific reverse transcription PCRs we demonstrate that this ectopic transcription results in the synthesis of RNA from the SV40 promoter in a direction opposite to the downstream reporter gene in a strand-specific manner. The unleashing of the bidirectionality of the SV40 promoter activity and a breach of the transcription barrier seems to depend on depletion of CGGBP1 and loss of CTCF binding proximal to the SV40 promoter. RNA-sequencing reveals that CGGBP1-regulated CTCF-binding sites act as barriers to transcription at multiple locations genome-wide. These findings suggest a role of CGGBP1-dependent binding sites in restricting ectopic transcription.

Performing ultrasonic nondestructive testing experiments on insulators and then using machine learning algorithms to classify and identify the signals is an important way to achieve an intelligent diagnosis of insulators. However, in most cases, we can obtain only a limited number of data from the experiments, which is insufficient to meet the requirements for training an effective classification and recognition model. In this paper, we start with an existing data augmentation method called DBA (for dynamic time warping barycenter averaging) and propose a new data enhancement method called AWDBA (adaptive weighting DBA). We first validated the proposed method by synthesizing new data from insulator sample datasets. The results show that the AWDBA proposed in this study has significant advantages relative to DBA in terms of data enhancement. Then, we used AWDBA and two other data augmentation methods to synthetically generate new data on the original dataset of insulators. Moreover, we compared the performance of different machine learning algorithms for insulator health diagnosis on the dataset with and without data augmentation. In the SVM algorithm especially, we propose a new parameter optimization method based on GA (genetic algorithm). The final results show that the use of the data augmentation method can significantly improve the accuracy of insulator defect identification.

Background Epigenetic memory plays a critical role in the establishment and maintenance of cell identities in multicellular organisms. Polycomb and trithorax group (PcG and TrxG) proteins are responsible for epigenetic memory, and in flies, they are recruited to specialized DNA regulatory elements termed polycomb response elements (PREs). Previous transgene studies have shown that PREs can silence reporter genes outside of their normal context, often by pairing sensitive (PSS) mechanism; however, their silencing activity is non-autonomous and depends upon the surrounding chromatin context. It is not known why PRE activity depends on the local environment or what outside factors can induce silencing. Results Using an attP system in Drosophila, we find that the so-called neutral chromatin environments vary substantially in their ability to support the silencing activity of the well-characterized bxdPRE. In refractory chromosomal contexts, factors required for PcG-silencing are unable to gain access to the PRE. Silencing activity can be rescued by linking the bxdPRE to a boundary element (insulator). When placed next to the PRE, the boundaries induce an alteration in chromatin structure enabling factors critical for PcG silencing to gain access to the bxdPRE. When placed at a distance from the bxdPRE, boundaries induce PSS by bringing the bxdPREs on each homolog in close proximity. Conclusion This proof-of-concept study demonstrates that the repressing activity of PREs can be induced or enhanced by nearby boundary elements., BMC Biology, 19 (1), ISSN:1741-7007

The organization of the genome into transcriptionally active and inactive chromatin domains requires well-delineated chromatin boundaries and insulator functions in order to maintain the identity of adjacent genomic loci with antagonistic chromatin marks and functionality. In plants that lack known chromatin insulators, the mechanisms that prevent heterochromatin spreading into euchromatin remain to be identified. Here, we show that DNA Topoisomerase VI participates in a chromatin boundary function that safeguards the expression of genes in euchromatin islands within silenced heterochromatin regions. While some transposable elements are reactivated in mutants of the Topoisomerase VI complex, genes insulated in euchromatin islands within heterochromatic regions of the Arabidopsis thaliana genome are specifically down-regulated. H3K9me2 levels consistently increase at euchromatin island loci and decrease at some transposable element loci. We further show that Topoisomerase VI physically interacts with S-adenosylmethionine synthase methionine adenosyl transferase 3 (MAT3), which is required for H3K9me2. A Topoisomerase VI defect affects MAT3 occupancy on heterochromatic elements and its exclusion from euchromatic islands, thereby providing a possible mechanistic explanation to the essential role of Topoisomerase VI in the delimitation of chromatin domains.

To address the issue of low accuracy in insulator object detection within power systems due to a scarcity of image sample data, this paper proposes a method for identifying insulator objects based on improved few-shot object detection through feature reweighting. The approach utilizes a meta-feature transfer model in conjunction with the improved YOLOv5 network to realize insulator recognition under conditions of few-shot. Firstly, the feature extraction module of the model incorporates an improved self-calibrated feature extraction network to extract feature information from multi-scale insulators. Secondly, the reweighting module integrates the SKNet attention mechanism to facilitate precise segmentation of the mask. Finally, the multi-stage non-maximum suppression algorithm is designed in the prediction layer, and the penalty function about confidence is set. The results of multiple prediction boxes are retained to reduce the occurrence of false detection and missing detection. For the poor detection results due to a low diversity of sample space, the transfer learning strategy is applied in the training to transfer the entire trained model to the detection of insulator targets. The experimental results show that the insulator detection mAP reaches 29.6%, 36.0%, and 48.3% at 5-shot, 10-shot, and 30-shot settings, respectively. These findings serve as evidence of improved accuracy levels of the insulator image detection under the condition of few shots. Furthermore, the proposed method enables the recognition of insulators under challenging conditions such as defects, occlusion, and other special circumstances.

The measurement for the surface electric field intensity of insulators based on electroluminescent effect is a non-contact measurement. By spraying a coating of epoxy paint mixed with ZnS:Cu electroluminescence powder on the surface of insulators, the part with high surface electric field intensity would be the first to glow. As the applied voltage increases, the area of luminous and the brightness increase. Therefore, the surface electric field distribution can be deduced by photographing and analyzing the luminescence of insulator surface coating. This method has successfully measured the surface electric field intensity distribution of disc insulators in GIL. Without the use of electric field probe, this method eliminates the electric field distortion caused by the probe completely. Besides, the permittivity of the coating can be decided according to the permittivity of the insulator material, and so eliminate the electric field distortion caused by the coating. The measure results of this method are in good agreement with reality.

Wide bandgap semiconductors are currently considered as the building blocks which revolutionized many areas of nanoscience and nanotechnologies. Among them, silicon carbide has been quickly emerging as one of the most interesting materials due to its remarkable physical, chemical, mechanical, electrical properties along with its biocompatibility and its feasibility for a wafer-scale production using standard MEMS processes. Inspired by these advantages, considerable number of studies have been devoted to the development of various SiC-based electronic devices over the past years. Despite these great achievements, however, it is realized that existing sensing devices usually rely on SiC in the forms of bulk or thin film, which still exhibit relatively poor sensitivity and unstable operation due to the limitation of their surface-to-volume ratios. Another key bottleneck of these existing sensing devices lies in the impossibility to integrate SiC onto soft and stretchable substrates due to its rigid and brittle nature, which significantly hamper the broader applications of SiC in the fast-emerging field of bioelectronics. Therefore, the research activities in the framework of my Ph.D. candidature aimed to establish reliable and sustainable protocols to overcome these two critical challenges. The focuses of my research work are placed on the fabrication of SiC nanowires on SiO2 insulators and stretchable SiC microstructures integrated onto polymeric substrates with a high level of structural perfection. Towards these goals, I have successfully fabricated Si NWs on insulator by using a combination of electron beam lithography and thermal wet oxidation techniques. The temperature sensing devices based on SiC NWs exhibit a high TCR compared to their bulk counterparts. On the other hand, I successfully established an effective protocol to transfer rigid SiC microstructures onto polymeric substrates and subsequently, enhanced their stretchability by taking advantages of structural design approaches.

Rising energy and raw material prices, dwindling resources, increased recycling, and the need for sustainable management have led to growth in the smart materials sector. In recent years, the importance and diversity of bio-based adhesives for industrial applications has grown steadily. This article focuses on the production and characterization of insulation panels consisting of peat moss and two bio-based adhesives. The panels were pressed with tannin and animal-based resins and compared to panels bonded with urea formaldehyde. The physical–mechanical properties, namely, thermal conductivity (TC), water vapor diffusion resistance, modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), compression resistance (CR), water absorption (WA) and thickness swelling (TS) were measured and analyzed. The results show that the insulation effectiveness and mechanical stability of moss panels bound with tannin and animal glue are comparable to standard adhesives used in the composite industry.

HSV-1 is a human pathogen that establishes a lifelong infection in the host. HSV-1 is transported by retrograde axonal transport to sensory neurons in the peripheral nervous system where latent viral genomes can reactivate. The resulting virus travels via anterograde axonal transport to the periphery and can cause clinical disease. CTCF insulators flank the LAT and IE regions of HSV-1 and during latency and maintain the integrity of transcriptional domains through a myriad of functions, including enhancer-blocking or barrier-insulator functions. Importantly, during reactivation, CTCF protein is evicted from the HSV-1 genome, especially from the CTRL2 insulator. CTRL2 is a functional insulator downstream of the 5′exon region of the LAT, so these results suggest that the disruption of this insulator may be required for efficient HSV-1 reactivation. To further explore this, we used a recombinant virus containing a deletion of the CTRL2 insulator (ΔCTRL2) in a rabbit ocular model of HSV-1 infection and induced reactivation. We show that, in the absence of the CTRL2 insulator, HSV-1 established an equivalent latent infection in rabbits, but those rabbits failed to efficiently reactivate from latency. Furthermore, we found a significant decrease in the expression of the gene Us9-, a gene that codes for a type II membrane protein that has been shown to be required for anterograde transport in neurons. Taken together, these results suggest that the functions of the CTRL2 insulator and Us9 activation in reactivating neurons are intrinsically linked through the regulation of a gene responsible for the axonal transport of HSV-1 to the periphery.

For the benefit of knowing the method of insulator deicing using hot water, this paper investigated the physical aspects of propagation and the spatial temperature distribution of a hot water jet in the air. The numerical calculation model for the water jet flow field was established and validated, and the temperature spatial variation rule and influencing factors of the water jet were analyzed. The results indicate that the water column breaks as the distance increases. The numerical calculation results and the experimental results of the water jet flow field were approximated. As the distance increases, the mass entrainment rate of the water jet gradually increases, and the normalized axis velocity decreases approximately linearly. The jet temperature rises with the rise in the initial temperature of the hot water, and the rising rate decreases with the increase in distance. The temperature of the water jet falls as the jet distance increases. With the rise in the outlet pressure, the temperature of the water jet drops slightly. The influence of environmental wind speed on the water jet temperature is more significant than ambient temperature—the water jet temperature increases as the nozzle diameter increases. The thorough deicing efficiency is most outstanding when the hot water output temperature is around 86 °C and the jet pressure is ~3.5 MPa.

Rail transit systems are one of the most important and popular types of transit systems used daily in metropolitan areas all around the world. The third rail is one of the providers of traction power in electrified rail systems, but it faces several issues, such as insulator failures. The purpose of this study is to investigate the causes of insulator failures, which have not been comprehensively studied and presented in the literature. To accomplish this objective, eight transit systems with third rails were selected to (1) investigate the characteristics of third-rail systems, (2) determine the causes of insulator failures, (3) analyze the costs associated with insulator failures, and (4) determine mitigating practices to reduce the number and cost of insulator failures. After a thorough literature review, details of eight case studies were collected from different transit agencies, and their subject matter experts were asked to complete a survey and provide input. The results revealed that a build-up of dirt was the major cause of the 17 identified causes of insulator failures; carbon dust and dirt were identified as the most present particles in third-rail systems. It was noted that transit agencies often implement multiple mitigating practices such as cleaning the insulator, performing visual inspections, and conducting regular maintenance to reduce the number and cost of insulator failures. The findings of this study will help decision-makers for transit systems make timely decisions to prevent third-rail insulator failures and adopt appropriate practices that best fit their transit system.

Synthetic biology circuits are often constructed with multiple gene expression units assembled in close proximity, and they can be used to perform complex functions in embryonic stem cells (ESCs). However, mutual interference between transcriptional units has not been well studied in mouse ESCs. To assess the efficiency of insulators at suppressing promoter interference in mouse ESCs, we used an evaluation scheme in which a tunable tetracycline response element promoter is connected to a constant Nanog promoter. The chicken hypersensitive site 4 (cHS4) insulator, widely used both for enhancer blocking and for barrier insulation in vitro and in vivo, was positioned between the two expression units for assessment. By inserting the cassette into various loci of the mouse ESC genome with PiggyBac transposon, we were able to quantitatively examine the protective effect of cHS4 by gradually increasing the transcriptional activity of the tetracycline response element promoter with doxycycline and then measuring the transcriptional activity of the Nanog promoter. Our results indicate that the cHS4 insulator has minimal insulating effects on promoter interference in mouse ESCs. Further studies show that the cHS4 insulation effect may be promoter specific and related to interaction with CCCTC‐binding factor‐mediated loop formation. In addition, we also compared DNA transposition and transgene expression with or without the cHS4 insulator using well‐established ESC reporters. The results indicate that cHS4 has no apparent effects on DNA transposition and transgene expression levels, but exerts modest protective effects on long‐term transgene silencing., Here we investigated the effect of the chicken hypersensitive site 4 (cHS4) insulator on PiggyBac transposon‐based vectors for gene transfer in mouse embryonic stem cells. The presence of the cHS4 insulator between two transcription units did not make any significant difference on suppression of promoter interference and transposition efficiency. Positioning of the cHS4 insulator at both ends of expressing units provided only a modest effect on preventing transgene silencing.

The article summarizes the results of research in four selected sites (observations) on the impact of surface power lines on bird death in the area of Nakhchivan Autonomous Republic in 2016-2017. Studies show that electrical wires have a major impact on bird death during the spring migration and nesting period. We determined that 225 individual of 27 species were killed by electric shock in selected areas, while 16 individuals belonging to 3 predator bird species were exposed to this threat. Two of these species are in the World Red List. The next plot with high mortality rate was the Cananbar well - Shikhmahmud plain (2 km), although we did not make a research here for the first two months. An average mortality rate of birds here were 2.72 individuals/km. The electric poles in the selected Nakhchivan - Shikhmahmud road (4 km) consisted mainly of wooden material and were sometimes replaced with reinforced concrete. We attribute the fact that the percentage of deaths in this area is lower than other stations because of the poles are more wooden. Among the dead birds some species belonging to the Red List of the World (Falco naumanni and Coracias garrulus). As we already mentioned, beside the overhead electric wires were mainly dangerous to Ciconia ciconia, Buteo rufinus and eagles. The dead and wounded species were recorded only one to four km from the electric line. Among the most common species exposed electric shocks were: Columba livia, Merops apiaster, Corvus frugilegus, Sturnus vulgaris and Passer domesticus. A total of 3,225 birds from 26 species were killed by the private electric shock during the study, four birds could not be identified (unknown species). When looking at the process from a landscape-species perspective, bird species - those most exposed to the electric wires are: less open, open space (loos); forest landscape (fl); residential areas (ra) and less grove areas (lga). Keywords: Power lines; Insulator; Power poles; Biotope; Migration; Nesting References Abdunazarov, B.B. (1987). Otsenka gibeli ptits na liniyakh elektroperedach sredney moshchnosti (6-35 kv) v Uzbekistane. Mlekopitayushchiye i ptitsy Uzbekstana. Dashkent (in Russian) Barrientos R, Ponce C, Palacin C, Martin CA, Martin B, et al. (2012) Wire marking results in a small but significant reduction in Avian mortality at power lines: A BACI designed study. PLoS ONE 7: e32569. https://doi.org/10.1371/journal.pone.0032569 Bernardino, J., Bevanger, K., Barrientos, R., Dwyer, J.F., Marques, A.T., Moreira, F. (2018). Bird collisions with power lines: State of the art and priority areas for research. Biological Conservation, 222, 1-13, https://doi.org/10.1016/j.biocon.2018.02.029 Brown WM, Drewein RC (1995) Evaluation of 2 power-line markers to reduce crane and waterfowl collision mortality. Wildl Soc Bull 23: 217-227. Dwyer, J.F., Harness, R.E., Donohue, P. (2014) Predictive model of avian electrocution risk on overhead power lines. Conserv Biol 1228: 159-168. https://doi.org/10.1111/cobi.12145 Erickson WP., Johnson GD, Young Jr DP (2005) A summary and comparison of bird mortality from anthropogenic causes with an emphasis on collisions. General Technical Report PSW-GTR-191. U.S. Department of Agriculture, Washington, D.C. Ferrer, M. (1990). Electrocutions of raptors on power lines in Southwestern Spain. Journal of Field ornithology, 62(2), 181-190 Garrido JR, Fernandez-Cruz M (2003) Effects of power lines on a White Stork (Ciconia ciconia) population in central Spain. Ardeola 50: 191-200. Guil F, Fernandez-Olalla M, Moreno-Opo R, Mosqueda I, Gomez ME, et al. (2011) Minimizing mortality in endangered raptors due to power lines: the importance of spatial aggregation to optimize the application of mitigation measures. PLoS ONE 6: e28212. https://doi.org/10.1371/journal.pone.0028212 Jenkins AR, Smallie JJ, Diamond D (2010) Avian collisions with power lines: A global review of causes and mitigation with a South African perspective. Bird Conserv Int 20: 263-278. https://doi.org/10.1017/S0959270910000122 Karyakin I.V. (2012). Birds of Prey and Power Lines in Northern Eurasia: What are the Prospects for Survival? Raptors Conservation, 24, 69-85. Karyakin I.V., Nikolenko E.G., Vazhov S.V., Bekmansurov R.H. (2013). Activities on bird protection from electrocution on power lines in the Altai Kray and the Republic of Altai and their influence on conservation of the Steppe Eagle Population in Altai, Russia. Raptor Conservation, 26, 44-60 Lehman RN (2001) Raptor electrocution on power lines: current issues and outlook. Wildl Soc Bull 29: 804-813. Dwyer JF, Mannan RW (2007) Preventing Raptor Electrocutions in an Urban Environment. J Raptor Res 41: 259-267. https://doi.org/10.3356/0892-1016(2007)41[259:PREIAU]2.0.CO;2 Lehman RN, Kennedy PL, Savidge JA (2007) The state of the art in raptor electrocution research: A global review. Biol Conserv 136: 159-174. https://doi.org/10.1016/j.biocon.2006.09.015 Levashkin, A.P. (2008). Rezul'taty proverki gnezdovykh yashchikov dlya dlinnokhvostoy neyasyti v Bogorodskom rayone Nizhegorodskoy oblasti, Rossiya. Perenatyye khishchniki i ikh okhrana. N.Novgorod. APD (in Russian). Longcore T, Rich C, Mineau P, MacDonald B, Bert DG, et al. (2012) An estimate of mortality at communication towers in the United States and Canada. PLoS ONE 7: e34025. https://doi.org/10.1371/journal.pone.0034025 Longcore T, Rich C, Mineau P, MacDonald B, Bert DG, et al. (2013) Avian mortality at communication towers in North America: which species, how many, and where? Biol Conserv 158: 410-419. https://doi.org/10.1016/j.biocon.2012.09.019 Loss, S. R., Will, T., & Marra, P. P. (2014). Refining estimates of bird collision and electrocution mortality at power lines in the United States. PloS one, 9(7), e101565. https://doi.org/10.1371/journal.pone.0101565 https://doi.org/10.1371/journal.pone.0101565 Mammadov, A.F. (2006). Taxonomic spectrum of ornithofauna of Nakhchivan Autonomous Republic. News of ANAS. The series of Biology Sciences, 3-4, 85-91 (in Azerbaijan) Mattsina, A.I. (2008). Kratkiy obzor metodov zashchity ptits ot porazheniya elektricheskim tokom na liniyakh elektroperedachi. Perenatyye khishchniki i ikh okhrana. N. Novgorod. APD (in Russian) McIntyre CL (2012) Quantifying sources of mortality and wintering ranges of Golden Eagles from interior Alaska using banding and satellite tracking. J Raptor Res 46: 129-134. https://doi.org/10.3356/JRR-10-96.1 Rioux S, Savard JPL, Gerick AA (2013) Avian mortalities due to transmission line collisions: A review of current estimates and field methods with an emphasis on applications to the Canadian electric network. Avian Conserv Ecol 8: 7. https://doi.org/10.5751/ACE-00614-080207 Shaw JM, Jenkins AR, Smallie JJ, Ryan PG (2010) Modelling power-line collision risk for the Blue Crane Anthropoides paradiseus in South Africa. Ibis 152: 590-599. https://doi.org/10.1111/j.1474-919X.2010.01039.x Smallwood KS (2013) Comparing bird and bat fatality-rate estimates among North American wind-energy projects. Wildl Soc Bull 37: 19-33. https://doi.org/10.1002/wsb.260. Sultanov E. (2003). Resource about specially protected and important ornithological areas. Baku (in Russian) Talibov, T.H. (1999). Conservation of rare animal species and their gene pool in Nakhchivan Autonomous Republic. Baku (in Russian).

In this paper, the heat balance integral method was employed to solve the internal temperature of ice layer and the position of melting interface by stages, due to its main advantage of converting the governing partial differential equation to an ordinary differential one, which can effectively reduce numerical efforts. Then the deicing time of hot water for insulator was calculated and analyzed. Taking LXY-120 insulator as the verification object, after natural icing at Xuefeng mountain natural icing test base, the validation experiments of deicing time were carried out in the natural environment. The initial water temperature and outlet pressure were optimized for deicing efficiency. Finally, the leakage current of water jet was measured. The research results indicate that the deicing rate increases and the energy consumption gradually decreases as the initial temperature of hot water increases. As the outlet pressure increases, the deicing rate increases. For the deicing condition of 1.2 mm nozzle, ambient temperature of -1 °C, wind speed of 3 m/s, ice weight of 2 kg/piece and deicing distance of 2 m, when the initial temperature of hot water and outlet pressure are 85.21 °C and 3.35 MPa respectively, the comprehensive deicing efficiency is the highest. The leakage current through water jet decreases with the increasing distance. The leakage current increases with the increase of water conductivity and outlet pressure. Hot water deicing for insulator in 110 kV system can be carried out according to the safety distance of the existing regulation.

Domain adaptive object detection aims to build an object detector for the unlabeled target domain by transferring knowledge from a well-labeled source domain, which can alleviate the problem of cumbersome labeling of object detection in cross-scene power transmission line inspection. Remarkable advances are made recently by mitigating distributional shifts via hierarchical domain feature alignment training of detection networks. However, domain adaptive object detection is still limited in learning the invariance representation of multi-scale features. Specifically, the scale of objects varies in the scenes of aerial inspection, which hinders the knowledge transfer from the labeled source domain. In this paper, we propose a multi-scale feature enhanced domain adaptation method for cross-domain object detection of power transmission lines inspection. The proposed method consists of two components: 1) Multi-Scale Fusion Feature Alignment module (MSFA) to strengthen similar representation characteristics of different scales object in domain adaptive by utilizing context information conveyed from other levels; 2) Multi-Scale Consistency Regularization module (MSCR) to jointly optimize the multi-scale feature learning of each level, which promotes domain invariant feature learning at each level. Experimental results demonstrate that our method significantly increases the performance of the object detector in several cross-scene transmission line inspection tasks.

In recent years, the electrical performance of polluted suspension insulators operating in coastal foggy regions has attracted wide attention because of the occurrence of flashover. Surface wetting by salt fog accretion increases the surface conductivity and degrades the flashover voltage of insulators. Normally, the effect of conductivity under fog condition and pre-contamination on the flashover of polluted insulators are analyzed separately. Therefore, this does not reveal the flashover characteristic in salt fog, which requires further research. This paper describes salt fog experiments with an AC test voltage conducted using suspension insulators in a 110-kV power system. The electrical strength performance of insulators with salt fog treatments is analyzed, and the effects of salt deposit density (SDD) and the fog water conductivity (FWC) on the flashover of three types of suspension insulators are studied. The concept of additional SDD is proposed to quantify analyze the effects of salt fog. The results show that there is less dependence on FWC at higher pollution levels than at lower pollution levels. That is, the effect of FWC on 50% AC flashover voltage ($U_{50}$ ) can be neglected for SDD >0.15 mg/cm2, whereas FWC has a strong effect on $U_{50}$ for SDD 2. FWC has a greater influence on $U_{50}$ of ceramic insulators than on that of silicone rubber insulator. A model for calculating the critical flashover voltage of insulators is proposed by considering the combined effect of FWC and pre-polluting SDD.

The electrical performance of insulators under comprehensive conditions including low air pressure, pollution and icing, is an important basis for the selection of external insulation. However, the problem of cold wet deposition has not attracted extensive and considerable interest in research. Based on flashover tests of suspension insulators in field test station, the AC flashover performance of insulators was studied. The results show that the duration of existence of the arc throughout the composite insulator surface in case of condensation was significantly lower than that in case of freezing fog flashover because of a change of the sheds surface roughness, which leads the arc melt the frozen fog droplets on the sheds surface and extends its flashover time. Compared with the flashover characteristics of the hydrophilic insulators in frost fog, the composite insulators exhibited clear arc extinguishing and arc starting phenomena. Moreover, the wind velocity has affected the flashover performance of suspension insulators in cold fog. Studying flashover characteristics of suspension insulators can contribute to the design of the external insulation of transmission lines and substations under natural cold fog and wet deposition regions.

Starptautiskās attiecības un diplomātija Socioloģija, politoloģija un antropoloģija International Relations and Diplomacy Sociology, Politics and Anthropology Maģistra darba mērķis ir noskaidrot, kā mainījusies Afganistānas vieta starp reģionālajiem drošības kompleksiem laika periodā no 2001 – 2021.gadam, kas darbā tiek analizēts izmantojot reģionālās drošības kompleksa teoriju. Izpildot darba mērķi tiek pārbaudīta hipotēza, ka pētāmā perioda laikā Afganistāna ir saglabājusi izolatora statusu, jo tās drošības problēmas nav pietiekami vienojošas un reģionu ietekmējošas, lai veidotu jaunu drošības kompleksu ar sevi iekšienē. Darbā tiek analizēta reģionālo drošības kompleksu teorija, teoriju veidojošās daļas un aktori, kas ietilpst šajos kompleksos. Tiek apskatīti reģionālās drošības kompleksu teorijas veidojošie un ietekmējošie faktori, kas nosaka, tā vietu kompleksu iekšienē un funkcijas, ko tie pilda. Darbā tiek apskatīta drošībošanas un atdrošībošanas nozīme šo kompleksu veidošanās procesā un vēlāk darbā, izmantojot teorijas dotos ieskatus par šiem procesiem, tiek apskatīti reģionu ietekmējošie Afganistānas politiskie notikumi, kas varētu būt par pamatu valsts drošībošanai vai atdrošībošanai. Tāpat, darbā tiek izpētīta reģionālās drošības kompleksu teorijas veidojošā aktora izolatora skaidrojums, īpašības, funkcijas un raksturojums, kura loma darbā tiek piedēvēta Afganistānai. Pamatojoties un Barija Buzena, teorijas pamatlicēja, analīzi par izolatoriem teorijas ietvaros, darbā tiek pārbaudīts, vai Afganistāna joprojām ir saglabājusies tā statusu pētāmā perioda laikā. Papildus, lai noteiktu iespējamās lomas izmaiņas, tiek vērtētas savstarpējās blakus esošo drošības reģionu valstu attiecības ar Afganistānu, ko ietekmē valsts politiskā darbība, valstu draudzīgums un naidīgumus ar Afganistānu, vēsturiskie, ekonomiskie, teritoriālie, etniskie un kulturālie faktori. Veicot Afganistānas vietas izpēti reģionālo drošības kompleksu vidū, kas tika veikta izmantojot reģionālo drošības kompleksu teoriju, hipotēze tiek apstiprināta. Vietas nemainīšanās tiek pamatota ar valsts valdības starptautisku izolāciju, valsts pievēršanos iekšpolitisko problēmu risināšanai ne iesaisti reģionālā līmeņa problēmu risināšanā, draudi, par ko satraukts reģions ir teroristu grupējuma IS-K vērsti. Tāpat, valstis arī pievēršās citu drošības kompleksu problēmu risināšanai, kuru draudu līmenis tām ir bīstamāks un tamdēļ padara par prioritārām. The objective of the master's thesis is to find out how the place of Afghanistan has changed among the regional security complexes in the period from 2001 to 2021, which is analyzed using the theory of the regional security complexes. The hypothesis, that Afghanistan has maintained it’s status as an insulator state during the study period, because it’s security problems are not unifying and affecting the region in that scale that it builds a new security complex within itself, is being verified. The work analyzes the theory of regional security complexes, the components of the theory and the actors that belong in those complexes. The paper looks deeper into the factors forming and influencing the theory of regional security complexes, what determines the place within the complexes and the functions the actors perform. The paper examines the role of securitization and desecuritization role in the process of forming of these complexes, and later, using the provided theoretical insights of those processes, author examines the political events in Afghanistan that are affecting the region, which could be the basis for securitization or desecuritization of the state. Also, the work studies the explanation, properties, functions and characteristics of the insulator state in the forming the theory of regional security complexes. Based on the analysis of Barry Buzan, the founder of the theory, insulator is the role of which is attributed to Afghanistan and is examined in the work if it is still relevant to Afghanistan in the period from 2001. till 2021. In addition, paper looks into historical, economic, territorial, ethnic and cultural factors affecting the country's relations with Afghanistan, which are influenced by the country's political activities, friendliness and hostility towards other states, and are important factors that determine possible changes of the role of Afghanistan. It is concluded that hypothesis is proven. The insulator state status is justified by the international isolation of the national government, the country's lack of involvement in solving problems at the regional level and the threat that the region is concerned about comes from the terrorist group IS-K. States also have to addressed other security challenges that pose a more dangerous threat to them and therefore make them a priority.

Moiré superlattices have recently been extensively studied in both electronic and photonic systems, e.g., magic-angle bilayer graphene showing superconductivity and twisted bilayer photonic crystals leading to magic-angle lasers. However, the moiré physics is barely studied in the field of magnonics, i.e., in using spin waves for information processing. In this work, we report magnon flat-band formation in twisted bilayer magnonic crystals at the optimal "magic angle" and interlayer exchange coupling combination using micro magnetic simulations. At the flat-band frequency, magnons undergo a strong two-dimensional confinement with a lateral scale of about 185 nm. The magic-angle magnonic nanocavity occurs at the AB stacking region of a moiré unit cell, unlike its photonic counterpart which is at the AA region, due to the exchange-induced magnon spin torque. The magnon flat band originates from band structure reformation induced by interlayer magnon-magnon coupling. Our results enable efficient accumulation of magnon intensity in a confined region that is key for potential applications such as magnon Bose-Einstein condensation and even magnon lasing.

Polymers are widely used as insulation materials in the electrical industry because their existing electrical and mechanical properties can be altered by adding different types of additives. Successful prediction of the service life of the insulators used in the electrical industry is important for the reliability of the system. For this purpose, insulating materials are subjected to tests according to various standards. In this study, unlike the literature, a polymeric insulator was produced by adding 3 wt.% zinc oxide (ZnO), magnetite (Fe 3O 4), and nickel (Ni) into the polyester. The produced samples were subjected to the inclined plane test in accordance with ASTM (American Society for Testing and Materials) D-2303 standards. In order to analyze the electric and magnetic field distributions formed on the samples during the inclined plane test, first, the current flowing on the samples during the test was measured. Following this, analyses were carried out by creating a simulation model of the samples. Studies found in the literature mainly focus on two-dimensional investigation of the electrical field distribution. This study concentrates on the three-dimensional examination of the electrical field also considering the magnetic field distribution. Results of this study showed that prior numerical analysis gives insight into information about the real-life behavior of the samples.

En la Universidad Simón Bolívar, sede Barranquilla, se ha desarrollado una invención, que consiste en el desarrollo de un equipo para hacer recubrimientos en material compuesto, de metal reforzado con partículas, aplicados por el método de Arc Spray; Este equipo requiere de una boquilla con un material especial: aislante eléctrico, resistente a altas temperaturas y resistencia al desgaste abrasivo. El propósito del proyecto desarrollado fue obtener la boquilla requerida. En este artículo se presentan, primero, los resultados de la búsqueda de un material que cumpla los requisitos de la boquilla, la determinación de la tecnología para obtenerla; Luego se presenta el diseño a detalle la misma a partir de las restricciones dadas; Además, se muestra prototipo construido en plástico con impresora 3D y el desarrollo de pruebas de funcionalidad en la pistola de proyección térmica de ARC Spray. At the Simón Bolívar University, Barranquilla headquarters, an invention has been developed, which consists of the development of equipment to make coatings in composite material, metal reinforced with particles, applied by the Arc Spray method; This equipment requires a nozzle with a special material: electrical insulator, resistant to high temperatures and resistance to abrasive wear. The purpose of the developed project was to obtain the required nozzle. This article presents, first, the results of the search for a material that meets the requirements of the nozzle, the determination of the technology to obtain it; Then the design is presented in detail from the given constraints; In addition, prototype built in plastic with 3D printer and the development of functionality tests on the ARC Spray thermal spray gun are shown.

In this thesis the spinel ferrites, a class of materials, which are interesting for photocatalytic and spintronic applications, is thoroughly investigated with regard to their structural and magnetic properties in relation to the cation distribution. The main focus is set on two types of spinel ferrite thin films, namely ZnFe2O4 and Zn/Al doped NiFe2O4, which grow in the normal and inverse spinel crystal structure, respectively. The thin films are grown with reactive magnetron sputtering and studied using integral techniques like x-ray diffraction, super conducting quantum interference device (SQUID) magnetometry and ferromagnetic resonance with a conventional X-band and a vector network analyser setup. Furthermore, the element-selective techniques Rutherford backscattering, elastic recoil detection, x-ray absorption spectroscopy and x-ray magnetic circular dichroism are utilised. Zinc ferrite thin films are investigated to clarify the so far inconclusive findings regarding the dominating type of magnetism. The analysis shows that the magnetic properties strongly depend on the sputter power, i.e. the deposition rate of sample series grown on two different substrates. An indication for a spin glass like behaviour is found for high deposition rates using typical measurement schemes of a SQUID magnetometer. Zn/Al doped nickel ferrites are sought after as a magnetic insulator with a low magnetic damping. The investigation of the Zn/Al doped nickel ferrite thin films is divided into two main parts. The first deals with the cation distribution by comparing a Zn-deficient with a Zn-rich sample. A strong dependence of the structural and magnetic properties on the cation distribution is found. The changes in the Zn content strongly affect the magnetic damping and the g-factor. Furthermore, the promotion of scattering centers by A/B disorder leads to two-magnon scattering. The second part deals with the systematic variation of the Zn and Al content as the adaptation of the stoichiometry seems promising. Three different sample series, namely the Zn series, Al series and thickness series are investigated in detail. From the Zn series a clear dependence of the linewidth is evidenced and a low Zn content was found to yield the best results. The Al series shows that deviating from the ideal concentration of the Zn series either affects the coercivity or the Curie temperature, which are crucial properties in the search for soft magnetic insulators with a low magnetic damping at room temperature. Furthermore, in the thickness series the lowest magnetic damping is found for a 25 nm-thick sample. During this thesis progress towards the understanding and identification of the dominating type of magnetism in zinc ferrite thin films was made. In case of Zn/Al doped nickel ferrites, the growth of ferromagnetic insulators with a low magnetic damping was optimised and the thin films can now be utilised in spintronic applications. In dieser Arbeit werden die Spinellferrite, eine Materialklasse, die für photokatalytische und spintronische Anwendungen interessant ist, eingehend auf ihre strukturellen und magnetischen Eigenschaften in Abhängigkeit von der Kationenverteilung untersucht. Der Schwerpunkt liegt auf zwei Arten von Spinellferrit-Dünnschichten, nämlich ZnFe2O4 und Zn/Aldotiertes NiFe2O4, die in der normalen bzw. inversen Spinell-Kristallstruktur wachsen. Die Dünnschichtfilme werden durch reaktives Magnetron-Sputtern gezüchtet und mit integralen Techniken wie Röntgenbeugung, Magnetometrie mit supraleitenden Quanteninterferenzgeräten (SQUID) und ferromagnetischer Resonanz mit einem herkömmlichen X-Band Aufbau und einem Vektornetzwerkanalysator untersucht. Darüber hinaus werden die elementselektiven Techniken Rutherford-Rückstreu-Spektrometrie, elastische Rückstreudetektionsanalyse, Röntgenabsorptionsspektroskopie und magnetischer Röntgenzirkulardichroismus eingesetzt. Zinkferrit-Dünnschichtgfilme werden untersucht, um die bisher nicht eindeutigen Befunde bezüglich der dominierenden Art des Magnetismus zu klären. Die Analyse zeigt, dass die magnetischen Eigenschaften stark von der Sputterleistung, d.h. der Abscheiderate von Probenserien abhängen, die auf zwei verschiedenen Substraten gewachsen sind. Ein Hinweis auf ein spinglasähnliches Verhalten findet sich für hohe Abscheideraten unter Verwendung typischer Messverfahren eines SQUID-Magnetometers. Zn/Al-dotierte Nickelferrite werden als magnetischer Isolator mit geringer magnetischer Dämpfung gesucht. Die Untersuchung der Zn/Al-dotierten Nickel-Ferrit-Dünnschichtfilmen gliedert sich in zwei Hauptteile. Der erste Teil befasst sich mit der Kationenverteilung durch den Vergleich einer Zn-armen mit einer Zn-reichen Probe. Es wird eine starke Abhängigkeit der strukturellen und magnetischen Eigenschaften von der Kationenverteilung festgestellt. Die Veränderungen im Zn-Gehalt wirken sich stark auf die magnetische Dämpfung und den g-Faktor aus. Darüber hinaus führt die Förderung von Streuzentren durch A/B-Unordnung zu Zweimagnonenstreuung. Der zweite Teil beschäftigt sich mit der systematischen Variation des Zn- und Al-Gehalts, da die Anpassung der Stöchiometrie vielversprechend erscheint. Drei verschiedene Probenserien, nämlich die Zn-Serie, die Al-Serie und die Dicken-Serie werden im Detail untersucht. Bei der Zn-Serie zeigt sich eine deutliche Abhängigkeit der Linienbreite, und es wurde festgestellt, dass ein niedriger Zn-Gehalt zu den besten Ergebnissen führt. Die Al-Reihe zeigt, dass eine Abweichung von der idealen Konzentration der Zn-Reihe entweder die Koerzitivfeldstärke oder die Curie-Temperatur beeinflusst, welche entscheidende Eigenschaften bei der Suche nach weichmagnetischen Isolatoren mit einer geringen magnetischen Dämpfung bei Raumtemperatur sind. Darüber hinaus wird in der Dickenreihe die niedrigste magnetische Dämpfung für eine 25 nm-dicke Probe gefunden. Im Rahmen dieser Arbeit wurden Fortschritte beim Verständnis und der Identifizierung des dominierenden Magnetismus in dünnen Zinkferritschichten erzielt. Im Falle von Zn/Al-dotierten Nickelferriten wurde das Wachstum ferromagnetischer Isolatoren mit geringer magnetischer Dämpfung optimiert und die Dünnschichtfilme können nun in spintronischen Anwendungen genutzt werden. submitted by Julia Lumetzberger Dissertation Universität Linz 2022

В данной работе исследуется Ð´Ð²ÑƒÑ Ñ†ÐµÐ¿Ð½Ð°Ñ линия на 110 кВ, от которой питаются буровые установки, погружные электродвигатели, качающие нефть или воду. Обозначены основные параметры молнии, последствий удара молнии в опору и средств предотвращения Ð³Ñ€Ð¾Ð·Ð¾Ð²Ñ‹Ñ Ð¿ÐµÑ€ÐµÐ½Ð°Ð¿Ñ€ÑÐ¶ÐµÐ½Ð¸Ð¹. В комплексе EMTP смоделирована ВЛ для расчетов Ð³Ñ€Ð¾Ð·Ð¾Ð²Ñ‹Ñ Ð¿ÐµÑ€ÐµÐ½Ð°Ð¿Ñ€ÑÐ¶ÐµÐ½Ð¸Ð¹. Проанализирована молниезащита ВЛ 110 кВ при установке изоляторов на одну из цепей и без Ð½Ð¸Ñ ., This study examines a 110 kV two-circuit line that supplies drilling rigs, submersible motors, oil, or water. The main parameters of lightning, the consequences of lightning strike in the support and the means of preventing lightning overvoltages are indicated. EMTP simulated OHL for lightning overvoltage calculations. Lightning protection of 110 kV overhead lines was analyzed when installing insulators on one of the circuits and without them.

The advent of twisted moiré heterostructures as a playground for strongly correlated electron physics has led to a plethora of experimental and theoretical efforts seeking to unravel the nature of the emergent superconducting and insulating states. Among these layered compositions of two-dimensional materials, transition metal dichalcogenides are now appreciated as highly tunable platforms to simulate reinforced electronic interactions in the presence of low-energy bands with almost negligible bandwidth. Here, we focus on the twisted homobilayer WSe2 and the insulating phase at half-filling of the flat bands reported therein. More specifically, we explore the possibility of realizing quantum spin liquid (QSL) physics on the basis of a strong coupling description, including up to second-nearest neighbor Heisenberg couplings J1 and J2 as well as Dzyaloshinskii–Moriya (DM) interactions. Mapping out the global phase diagram as a function of an out-of-plane displacement field, we indeed find evidence for putative QSL states, albeit only close to SU(2) symmetric points. In the presence of finite DM couplings and XXZ anisotropy, long-range order is predominantly present with a mix of both commensurate and incommensurate magnetic phases., D.K. thanks L. Gresista and T. Müller for related work on the PFFRGSolver.jl package74 used for the FRG calculations. The DMRG calculations are based on the Tenpy package.75 D.K. and C.H. acknowledge support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project No. 277146847, SFB 1238 (Project No. C03). Y.H. and D.M.K. acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Grant No. RTG 1995 within the Priority Program SPP 2244 “2DMP” and within Germany’s Excellence Strategy—Cluster of Excellence Matter and Light for Quantum Computing (ML4Q) Grant No. EXC 2004/1-390534769. This work was supported by the Max Planck-New York City Center for Nonequilibrium Quantum Phenomena. The numerical simulations were performed on the CHEOPS cluster at RRZK Cologne, the JURECA Booster76 and JUWELS cluster77 at the Forschungszentrum Juelich, and the Raven cluster at MPCDF of the Max Planck society.

The accuracy of insulators and their defect identification by UAVs (unmanned aerial vehicles) in transmission-line inspection needs to be further improved, and the model size of the detection algorithm is significantly reduced to make it more suitable for edge-end deployment. In this paper, the algorithm uses a lightweight GhostNet module to reconstruct the backbone feature extraction network of the YOLOv4 model and employs depthwise separable convolution in the feature fusion layer. The model is lighter on the premise of ensuring the effect of image information extraction. Meanwhile, the ECA-Net channel attention mechanism is embedded into the feature extraction layer and PANet (Path Aggregation Network) to improve the recognition accuracy of the model for small targets. The experimental results show that the size of the improved model is reduced from 244 MB to 42 MB, which is only 17.3% of the original model. At the same time, the mAp of the improved model is 0.77% higher than that of the original model, reaching 95.4%. Moreover, the mAP compared with YOLOv5-s and YOLOX-s, respectively, is improved by 1.98% and 1.29%. Finally, the improved model is deployed into Jetson Xavier NX and run at a speed of 8.8 FPS, which is 4.3 FPS faster than the original model.

Insulators are one of the many components responsible for the reliability of electricity supply as part of transmission and distribution lines. Failure of the insulator can cause considerable economic problems that are much greater than the insulator cost. When the failure occurs on the transmission line, a large area can be without electricity supply or other transmission lines will be overloaded. Because of the consequences of the insulator’s failure, diagnostics of the insulator plays a significant role in the reliability of the power supply. Basic diagnostic methods require experienced personnel, and inspection requires moving in the field. New diagnostic methods require online measurement if it is possible. Diagnostic by measuring the leakage current flowing on the surface of the insulator is well known. However, many other quantities can be used as a good tool for diagnostics of insulators. We present in this article results obtained on the investigated porcelain insulators that are one of the most used insulation materials for housing the insulator’s core. Leakage current, dielectric loss factor, capacity, and electric charge are used as diagnostic quantities to investigate porcelain insulators in different pollution conditions and different ambient relative humidity. Pollution and humidity are the main factors that decrease the insulator´s electric strength and reliability.

Successive flashover would result in carbonized tracking on insulator surface and cause deterioration to the insulation. Thus, investigation of the tracking can be beneficial in understanding flashover characteristics during long-term operation. In this paper, DC flashover was operated on the insulator, and the image of tracking after successive discharge were captured. Improved differential box-counting method (IDBM) was applied to analyze these images based on fractal theory. Weighted item was suggested during the counting procedure for rectangle image with margin covered by cut-size box. Fractal dimension of the tracking was calculated according to the suggested method. It is claimed that the suggested method could estimate the discharge propagation property and deterioration characteristics on the insulator surface. Moreover, IDBM showed advantages in image pre-processing and deterioration property revealed compared to traditional box-counting method attributing to the consideration of color depth. This image analysis method shows universality in dealing with tracking image and could provide additional information to flashover voltage. This paper suggested a potential approach for the investigation of discharge mechanism and corresponding deterioration in future research.

Insulator is a very important equipment in an electric power system. Ceramic insulators have been widely used to support conductors in 20 kV power lines. The problem of ceramic insulators is that they are heavy, easily contaminated on the surface and require a lot of energy in the manufacturing process. Therefore, polymer insulators were developed. This paper presents the design of an epoxy resin polymer insulator with Titanium Dioxide (TiO2) as a nanofiller. The leakage current test was carried out in a high voltage laboratory by applying an AC high voltage of 50 Hz to the insulator dry conditions and the insulator wetted by rainwater contaminants. The results of the leakage current test in dry conditions are 487.6 μA, rainwater contaminated conditions are 594.93 μA, insulation resistance in dry conditions is 2.07 G-Ohms, and contaminated conditions are 1.41 G-Ohms. Based on the test results show that the insulator leakage current increases up to 22% when the surface of the insulator is contaminated with rainwater. Meanwhile, the insulation resistance decreased by up to 32% in conditions contaminated with rainwater. The value of leakage current and insulation resistance indicates that the epoxy resin insulator with TiO2 as filler is electrically feasible to use.

The surface discharge development processes of polluted porcelain insulators for power transmission lines are tightly related with the development of leakage current (LC), the characteristics of LC, the insulating condition, and discharge intensity of the insulator surface have an important significance for revealing the contamination discharge state of insulators. In order to analyze the LC characteristics of porcelain insulators in the process of pollution flashover, artificial pollution flashover tests on porcelain insulators were conducted in the artificial fog cabinet, and the characteristics of LC waveforms in time-domain and frequency-domain were simultaneously measured and analyzed during the tests. The results indicated that the amplitude of LC, fundamental harmonic, the third harmonic, and fifth harmonic had a strong correlation, the maximum of LC(Im), the rate of total harmonics (THD), and the phase difference of fundamental harmonic (θ) were used for the representation of the characteristics of the LC waveform. The LC has the characteristics of high amplitude, low proportion harmonic, and small phase difference between the fundamental harmonic and voltage before the flashover occurrence. The test results provide effective reference for porcelain insulators in pollution flashover forecasting.

We discuss the charge and the spin tunneling currents between two Bardeen-Cooper-Schrieffer (BCS) superconductors, where one density of states is spin-split by the proximity of a ferromagnetic insulator. In the presence of a large temperature bias across the junction, we predict the generation of a spin-polarized thermoelectric current. This thermospin effect is the result of a spontaneous particle-hole symmetry breaking in the absence of any polarizing tunnel barrier. The two spin components, which move in opposite directions, generate a spin current larger than the purely polarized case when the thermoactive component dominates over the dissipative one.

The precise location of insulators in infrared images is of great significance for insulator condition monitoring and fault diagnosis. Due to the characteristics of insulators themselves and the use of handheld infrared cameras, insulators usually appear in infrared images with different aspect ratios and main axis orientations. Therefore, it is very important and necessary to make full use of the prior knowledge of the insulator itself to accurately locate it. However, most of the existing methods use axial horizontal detection boxes to detect insulators, which cannot take into account the characteristics of the insulator well. When there are large overlapping areas of two horizontal detection boxes, the non-maximum suppression algorithm may lead to missed detection of the object. In order to further improve the accuracy of the detection algorithm, the proposed method makes full use of the prior features carried by the insulator itself, and optimizes Faster R-CNN from five aspects: rectangular box representation, feature extraction, candidate box generation, anchor design, and feature alignment. An oriented detection model for infrared images of insulators is constructed. Comparative experiments with a variety of mainstream detection methods were carried out on the constructed infrared dataset. The results show that the proposed method is superior to other models in detection accuracy. When the intersection and union ratio is 0.5, the average precision reaches 95.08%. In addition, it can also effectively predict the shape and angle information of insulators in complex scenes, laying a beneficial foundation for subsequent diagnosis automation tasks.

Mutations in enhancers have been shown to often underlie natural variation but the evolved differences between enhancer activity can be difficult to identify in vivo. Threespine sticklebacks (Gasterosteus aculeatus) are a robust system for studying enhancer evolution due to abundant natural genetic variation, a diversity of evolved phenotypes between ancestral marine and derived freshwater forms, and the tractability of transgenic techniques. Previous work identified a series of polymorphisms within an intronic enhancer of the Bone morphogenetic protein 6 (Bmp6) gene that are associated with evolved tooth gain, a derived increase in freshwater tooth number that arises late in development. Here we use a bicistronic reporter construct containing a genetic insulator and a pair of reciprocal two-color transgenic reporter lines to compare enhancer activity of marine and freshwater alleles of this enhancer. In older fish the two alleles drive partially overlapping expression in both mesenchyme and epithelium of developing teeth, but the freshwater enhancer drives a reduced mesenchymal domain and a larger epithelial domain relative to the marine enhancer. In younger fish these spatial shifts in enhancer activity are less pronounced. Comparing Bmp6 expression by in situ hybridization in developing teeth of marine and freshwater fish reveals similar evolved spatial shifts in gene expression. Together, these data support a model in which the polymorphisms within this enhancer underlie evolved tooth gain by shifting the spatial expression of Bmp6 during tooth development, and provide a general strategy to identify spatial differences in enhancer activity in vivo.

The HPSE gene encodes heparanase (HPSE), a key player in cancer, inflammation, and autoimmunity. We have previously identified a strong HPSE gene enhancer involved in self-regulation of heparanase by negative feedback exerted in a functional rs4693608 single-nucleotide polymorphism (SNP) dependent manner. In the present study, we analyzed the HPSE gene insulator region, located in intron 9 and containing rs4426765, rs28649799, and rs4364254 SNPs. Our results indicate that this region exhibits HPSE regulatory activity. SNP substitutions lead to modulation of a unique DNA-protein complex that affects insulator activity. Analysis of interactions between enhancer and insulator SNPs revealed that rs4693608 has a major effect on HPSE expression and the risk of post-transplantation acute graft versus host disease (GVHD). The C alleles of insulator SNPs rs4364254 and rs4426765 modify the activity of the HPSE enhancer, resulting in altered HPSE expression and increased risk of acute GVHD. Moreover, rs4426765 correlated with HPSE expression in activated mononuclear cells, as well as with CD3 levels and lymphocyte counts following G-CSF mobilization. rs4363084 and rs28649799 were found to be associated with CD34+ levels. Our study provides new insight into the mechanism of HPSE gene regulation and its impact on normal and pathological processes in the hematopoietic system.

International audience; Immunoglobulin class switch recombination (CSR) plays a crucial role in adaptive immune responses through a change of the effector functions of antibodies and is triggered by T-cell-dependent as well as T-cell-independent antigens. Signals generated following encounter with each type of antigen direct CSR to different isotypes. At the genomic level, CSR occurs between highly repetitive switch sequences located upstream of the constant gene exons of the immunoglobulin heavy chain locus. Transcription of switch sequences is mandatory for CSR and is induced in a stimulation-dependent manner. Switch transcription takes place within dynamic chromatin domains and is regulated by long-range regulatory elements which promote alignment of partner switch regions in CSR centers. Here, we review recent work and models that account for the function of long-range transcriptional regulatory elements and the chromatin-based mechanisms involved in the control of CSR.

Polluted insulators seriously threaten the safe and stable operation of power grids, which attaches great significance to insulator contamination perception. Among the present methods, the non-contact approaches based on infrared images have gradually been widely used, as they are much more safe and are of low cost. However, the thermal effect of insulators is largely affected by meteorological conditions, which makes the infrared image-based methods less accurate. To solve the above problem, we take infrared image and meteorological parameters including humidity and temperature as input, and propose a feature fusion model to perceive insulator contamination in different weather conditions. Firstly, different feature extraction networks are used to perform feature extraction on the two types of data; secondly, the two features are concatenated to fuse together; thirdly, further feature extraction is performed and contamination is classified according to the pollution severity. Case studies show that the proposed method can better explore the relationship between humidity, temperature and pollution level of the insulators, thus can better separate the contamination grades and outperform the conventional infrared image based methods.

Detection and prevention of faults in overhead electric lines is critical for the reliability and availability of electricity supply. The disadvantages of conventional methods range from cumbersome installations to costly maintenance and from lack of adaptability to hazards for human operators. Thus, transmission inspections based on unmanned aerial vehicles (UAV) have been attracting the attention of researchers since their inception. This article provides a comprehensive review for the development of UAV technologies in the overhead electric power lines patrol process for monitoring and identifying faults, explores its advantages, and realizes the potential of the aforementioned method and how it can be exploited to avoid obstacles, especially when compared with the state-of-the-art mechanical methods. The review focuses on the development of advanced Learning Control strategies for higher manoeuvrability of the quadrotor. It also explores suitable recharging strategies and motor control for improved mission autonomy.

Detection and prevention of faults in overhead electric lines is critical for the reliability and availability of electricity supply. The disadvantages of conventional methods range from cumbersome installations to costly maintenance and from lack of adaptability to hazards for human operators. Thus, transmission inspections based on unmanned aerial vehicles (UAV) have been attracting the attention of researchers since their inception. This article provides a comprehensive review for the development of UAV technologies in the overhead electric power lines patrol process for monitoring and identifying faults, explores its advantages, and realizes the potential of the aforementioned method and how it can be exploited to avoid obstacles, especially when compared with the state-of-the-art mechanical methods. The review focuses on the development of advanced Learning Control strategies for higher manoeuvrability of the quadrotor. It also explores suitable recharging strategies and motor control for improved mission autonomy.

The genomes of higher eukaryotes are partitioned into topologically associated domains or TADs, and insulators (also known as boundary elements) are the key elements responsible for their formation and maintenance. Insulators were first identified and extensively studied in Drosophila as well as mammalian genomes, and have also been described in yeast and plants. In addition, many insulator proteins are known in Drosophila, and some have been investigated in mammals. However, much less is known about this important class of non-coding DNA elements in plant genomes. In this review, we take a detailed look at known plant insulators across different species and provide an overview of potential determinants of plant insulator functions, including cis-elements and boundary proteins. We also discuss methods previously used in attempts to identify plant insulators, provide a perspective on their importance for research and biotechnology, and discuss areas of potential future research.

Starting with twisted bilayer graphene, graphene-based moir\'e materials have recently been established as a new platform for studying strong electron correlations. In this paper, we study twisted graphene monolayers on trilayer graphene and demonstrate that this system can host flat bands when the twist angle is close to the magic angle of $1.{16}^{\ensuremath{\circ}}$. When monolayer graphene is twisted on ABA trilayer graphene, the flat bands are not isolated, but are intersected by a Dirac cone with a large Fermi velocity. In contrast, graphene twisted on ABC trilayer graphene (denoted AtABC) exhibits a gap between flat and remote bands. Since ABC trilayer graphene and twisted bilayer graphene are known to host broken-symmetry phases, we further investigate the ostensibly similar magic-angle AtABC system. We study the effect of electron-electron interactions in AtABC using both Hartree theory and an atomic Hubbard theory to calculate the magnetic phase diagram as a function of doping, twist angle, and perpendicular electric field. Our analysis reveals a rich variety of magnetic orderings, including ferromagnetism and ferrimagnetism, and demonstrates that a perpendicular electric field makes AtABC more susceptible to magnetic ordering.

U ovom diplomskom radu opisan je proces standardizacije kritičnih komponenata visokonaponskih mjernih transformatora. Dana je sažeta teorijska podloga o konstrukciji i principu rada mjernih transformatora. Uveden je i razrađen pojam kritične komponente, te su identificirane komponente različitih izvedbi mjernih transformatora koje se mogu smatrati kritičnima. Nastavno na identifikaciju kritičnih komponenata, analizirane su različite izvedbe kritičnih komponenata prema mehaničkim i električnim parametrima koji utječu na njihov izbor. Kao rezultat analize donjete su odluke o napuštanju ili redizajnu određenih izvedbi komponenata te je izrađena baza standardnih kritičnih komponenata. This thesis describes the process of standardization of critical components used in high voltage instrument transformers. A concise theory background on the construction and principle of operation of instrument transformers is given. The concept of critical component is introduced and elaborated, and components of instrument transformers that can be considered critical were identified. In addition to the identification of critical components, an analysis of critical components according to mechanical and electrical parameters that influence their choice was performed. As a result of the analysis, decisions were made to abandon or redesign certain component designs, and a database of standard critical components was developed.