The key to on-line partial discharge (PD) monitoring of power transformers is how to suppress interference effectively. This paper reports an interference qualitative and quantitative analysis on ...site using a fast Fourier transform (FFT) technique. Various periodic interferences have been found, which emanated from the carrier communication, thyristor switching, and high frequency protection signals of power system as well as radio broadcasting signals. LMS adaptive digital filter and FFT threshold digital filter can be used to eliminate continuous periodic noises for on-line PD monitoring. However, they suffer from their own intrinsic weaknesses. Therefore, a multi-band-pass digital filter based on FFT has been developed. It is a much better method for the purpose of suppressing continuous periodic interference. (4 pages)
Assisted by graphene oxide（GO）,nano-sized LiMn0.6Fe0.4PO4 with excellent electrochemical performance was prepared by a facile hydrothermal method as cathode material for lithium ion battery.SEM and ...TEM images indicate that the particle size of LiMn0.6Fe0.4PO4（S2）was about 80 nm in diameter.The discharge capacity of LiMn0.6Fe0.4PO4 nanoparticles was 140.3 mAh-g^1 in the first cycle.It showed that graphene oxide was able to restrict the growth of LiMn0.6Fe0.4PO4 and it in situ reduction of GO could improve the electrical conductivity of LiMn0.6Fe0.4PO4 material.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The key to on-line partial discharge (PD) monitoring of power transformers is how to suppress interference effectively. This paper reports an interference qualitative and quantitative analysis on ...site using a Fast Fourier Transform (FFT) technique. Various periodic interferences have been found, which emanated from the carrier communication, thyristor switching, and high frequency protection signals of the power system as well as radio broadcasting signals. LMS adaptive digital filters and FFT threshold digital filters can be used to eliminate continuous periodic noises for on-line PD monitoring. However, they suffer from their own intrinsic weaknesses. Therefore, a multi-band-pass digital filter based on FFT has been developed. It is an much better method for suppressing continuous periodic interferences.
Power transformers play a crucial role in operation of transmission and distribution systems. A dielectric failure in a power transformer could result in unplanned outages of power systems, which ...affect a large number of customers. In this paper, the application of two different networks to recognize patterns of partial discharge (PD) of power transformer models is studied. Eleven well-designed discharge models are presented as well. According to results of PD measurements and neural network (NN) training and testing, two different NN paradigms can recognize different PD sources for those data at the same voltage level. NN might misclassify those PD patterns or sources with data of different voltage level.
Static VAr compensator with neural network control Mumyakmaz, B.; Xianhe Jin; Changchang Wang ...
1999 IEEE Transmission and Distribution Conference (Cat. No. 99CH36333),
1999, Volume:
2
Conference Proceeding
Artificial neural networks (ANNs) have been used in many applications of pattern classification, speech synthesis and recognition, function approximation, associative memory and control. Because of ...their adaptive nature and parallel computational features, they are promising a lot of hope for future of engineering. In this study, an application of ANN in control has been presented. A static VAr compensator model that has been used to provide reactive energy for a given load was controlled using two multi-layer feed-forward neural networks. ANN control method used in this study was more speedy than classic feedback control system. Because of their adaptivity and generalization features, ANNs provided power factor error less than 2% while inputs contained harmonics in this study. Results show that ANNs could be used to control power electronic circuits in static VAr compensators.
Highly structured RNA molecules usually interact with each other, and associate with various RNA-binding proteins, to regulate critical biological processes. However, RNA structures and interactions ...in intact cells remain largely unknown. Here, by coupling proximity ligation mediated by RNA-binding proteins with deep sequencing, we report an RNA in situ conformation sequencing (RIC-seq) technology for the global profiling of intra- and intermolecular RNA-RNA interactions. This technique not only recapitulates known RNA secondary structures and tertiary interactions, but also facilitates the generation of three-dimensional (3D) interaction maps of RNA in human cells. Using these maps, we identify noncoding RNA targets globally, and discern RNA topological domains and trans-interacting hubs. We reveal that the functional connectivity of enhancers and promoters can be assigned using their pairwise-interacting RNAs. Furthermore, we show that CCAT1-5L-a super-enhancer hub RNA-interacts with the RNA-binding protein hnRNPK, as well as RNA derived from the MYC promoter and enhancer, to boost MYC transcription by modulating chromatin looping. Our study demonstrates the power and applicability of RIC-seq in discovering the 3D structures, interactions and regulatory roles of RNA.
Full text
Available for:
FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Hydrogen energy (H2) has been considered as the most possible consummate candidates for replacing the traditional fossil fuels because of its higher combustion heat value and lower environmental ...pollution. Photocatalytic hydrogen evolution (PHE) from water splitting based on semiconductors is a promising technology towards converting solar energy into sustainable H2 fuel evolution. Developing high-activity and abundant source semiconductor materials is particularly important to realize highly efficient hydrogen evolution as for photocatalysis technology. However, unmodified pristine photocatalysts are often unable to overcome the weakness of low performance due to their limitations. In recent years, transition metal phosphides (TMPs) were used as valid co-catalysts to replace the classic precious metal materials in the process of photocatalytic reaction owing to their lower cost and higher combustion heat value. What is more, bimetallic phosphides have been also caused widespread concern in H2 evolution reaction owing to its much lower overpotential, more superior conductivity, and weaker charge carriers transfer impedance in comparison to those of single metal phosphides. In this minireview, we concluded the latest developments of bimetallic phosphides for a series of photocatalytic reactions. Firstly, we briefly summarize the present loading methods of bimetallic phosphides (BMPs) anchored on the photocatalyst. After that, the H2 evolution efficiency based on BMPs as cocatalyst is also studied in detail. Besides, the application of BMPs-based host photocatalyst for H2 evolution under dye sensitization effect has also been discussed. At last, the current development prospects and prospective challenges in many ways of BMPs are proposed. We sincerely hope this minireview has certain reference value for great developments of BMPs in the future research.
Display omitted Bimetallic phosphides have been also caused widespread concern in H2 evolution reaction owing to its unique Advantages. In this minireview, we concluded the latest developments of bimetallic phosphides as cocatalyst for a series of photocatalytic H2 evolution reactions.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As a recyclable and inexhaustible renewable resource, chitin is one of the most abundant polysaccharides in nature. It has excellent biocompatibility, biodegradability, and non-toxicity and has been ...widely used in food packaging, tissue engineering, and other fields. Deep eutectic solvents (DESs) are regarded as a new generation of green solvents due to their excellent biocompatibility and stability. Recently, the use of DESs to process chitin has also received widespread attention. In this review, we first introduced DESs and chitin, then discussed the relationship between the properties of DESs and the applications in the extraction, dissolution, and functional materials of chitin. In addition, the related applications are classified and introduced. The opportunities and challenges for DESs when dealing with chitin systems are also summarized.
Deep eutectic solvents (DESs) as sustainable solvents for chitin extraction, dissolution, and functional materials.
This paper discusses methods for estimating reliability parameters of distribution transformers. The data analysis techniques presented have been developed through operating records provided for the ...period 1970 to 1993 by an Electric Utility Department in the USA. Calculation results show that the failure mode of distribution transformers can be represented by Weibull distribution. Both useful calculation methods and results of failure rates as well as MTTF (mean time to failure) are given in the paper.
•The model input combines vibration signals with corresponding time domain and frequency domain indicators.•The multi-kernel maximum mean discrepancies (MK-MMD) of the selected hidden layers are ...calculated and added to loss function.•The robustness of domain adaptive deep belief network (DA-DBN) model is improved by noise linear rectification in MK-MMD.
As the essential components of rotating machines, rolling bearings always operate in variable working conditions and suffer from different failure modes. To address the issue of lacking substantial labeled samples in new working conditions, a domain adaptive deep belief network (DA-DBN) is proposed for rolling bearing fault diagnosis. Firstly, the DBN model is pre-trained by the labeled samples which are composed of raw vibration signals and their corresponding time domain and frequency domain indicators. Secondly, the domain adaption method in transfer learning is applied to calculate the multi-kernel maximum mean discrepancies (MK-MMD) between the known working condition data and new working condition data in multiple layers. Thus, the loss function composed of MK-MMD and classification error can be obtained, and back propagation algorithm is used to fine-tune model parameters. Finally, the datasets with five fault patterns are collected to evaluate the performance of the DA-DBN. The results demonstrate that the proposed DA-DBN can achieve more than 92% fault classification accuracy under three noise levels; the average accuracy of fault classification under variable working conditions is 93.5%, which is the highest compared with other models.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
