The impact of short-term O2 contamination on the deposit-covered pipeline steel under a CO2-saturated solution was investigated using steel coupon and wire beam electrode. Results show that the brief ...exposure to O2 destroyed the FeCO3 film, and converted it into porous iron oxides, weakening its protection property. However, upon CO2 reinjection, the dense FeCO3 film regrew soon underneath the damaged FeCO3 layer on the bare steel, restoring its protective properties. Conversely, the localized corrosion beneath the deposits persisted and worsened, fueled by macro-cell current between the bare steel and the deposit-covered steel.
•The mechanism of UDC in CO2 saturated solution with short-term O2 contamination is analyzed using steel coupon and WBE.•The presence of silica particles will influence the growth of the FeCO3 film on the deposit-covered steel area.•Short-term O2 contamination in the CO2-saturated pipeline typically did not have a significant impact on bare steel.•Short-term O2 contamination in the CO2-saturated pipeline led to severe localized corrosion on the deposit-covered steel.
Distributed generation (DG) inverters can operate in the islanded mode and the grid-connected mode. When these DG inverters operate in the islanded mode, they often form a microgrid. The magnitude ...and phase of the main grid voltage deviate from the microgrid voltage. If the microgrid is connected to the main grid under such condition, it results in a high transient overcurrent that is harmful to the system. This article presents a new, simple, and effective resynchronization mechanism for the universal droop control (UDC) DG inverters to achieve a seamless transfer from the islanded mode to the grid-connected mode. Simulation and experimental results are provided to verify the effectiveness of the proposed method. The result shows that the high transient overcurrent can be avoided and a seamless connection/reconnection to the main grid can be achieved.
As a breakthrough technology, UDC (Under‐Display Camera) can achieve full display, also can increase panel proportion of mobile phones. It is the most likely way to balance the contradiction between ...front camera and display integrity settings. However, due to the design difference between the main and UDC areas, the display consistency is an important factor affecting the display effect and production yield of UDC panel. To solve this problem, this paper analyzes the reasons for the inconsistency between the main and UDC areas, as well as the defects of the current main solutions. An advanced debug scheme is proposed. It can significantly improve the accuracy of display brightness of UDC area, so as to improve the display effect of UDC panel.
•A Dynamic Object-Oriented Bayesian network (DOOBN) model is proposed for internal corrosion induced failure.•The DOOBN represents the probabilistic relationships among prevalent influencing risk ...factors and define their dependencies.•The results of the model are validated using filed data, an accuracy of 93.22% is observed.•The study serves as an early warning guide for the integrity management of pipelines.
Internal corrosion is a complex phenomenon that includes under-deposit corrosion (UDC), microbially influenced corrosion (MIC), erosion, and localized and uniform corrosion mechanisms. For robust risk management of pipelines, there is a need to study the interactions of risk factors in internal corrosion. It is necessary to monitor the variations of corrosion risk factors and assess the pipeline's failure likelihood as a function of time. A Dynamic Object-Oriented Bayesian network (DOOBN) model is developed for this purpose. The DOOBN model has helped represent the probabilistic relationships among prevalent influencing risk factors and define their conditional dependencies. There are 94 risk factors considered for the different internal corrosion mechanisms. Results show that the probability of UDC occurrence for a given pipeline is 58%, while MIC is 48%. The study also confirms the increase in asset failure rate with the rise in internal corrosion. Results of the model are validated using filed data, and an accuracy of 93.22% is observed. The study serves as an early warning guide for the integrity management of pipelines against internal corrosion.
Information system is a system that combines technology used to help human life. Not only helps facilitate information sistem activities, it also saves time, space and costs. Utilization of a website ...is useful in all fields because there are many and very broad and user-friendly features that can spoil the user's eyes. Activities that function to meet the needs of the general public are the meaning of public services as well as those related to other commodities such as goods, services and management provided by the organizers. In the health sector in public services, it is very necessary, especially in the service reservation process which still uses a queuing sistem in the form of taking queue numbers in the hospital lobby and waiting for hours, causing queues of visitors. The purpose of this study was to design a reservation information system at the hospital in order to increase the use of facilities and resources. The design of this hospital reservation information system is based on a website that was built using the user centered design method and tested using the SUS (Sistem Usability Scale) method which is in accordance with the criteria for the Sistem Usability Scale method which involves several respondents for information system acceptance
The article proposes an algorithm for decoding and representation in natural language of the Universal Decimal Classifycation (UDC) complex class numbers. The algorithm is based on the formal ...definition of correct class numbers using a generative grammar, which sets the list of structures starting with simple table codes of UDC classes. Then separate integers, auxiliary and independent class numbers are sequentially attached to the codes with special symbols of relations of classes, which compose the complex class number. The algorithm expresses the values of the analyzed complex indices by descriptions (names and notes) of the table classes included in the structure of the analyzed string. The class descriptions are accompanied with the logical connectors based on the functions of the auxiliary characters. They provide the idea on connection of concepts denoted in the class number. The algorithm action is described evidently for the analysis of combined index 539.4.019: 535-15+537.8.029.6. The proposed algorithm is applicable both to visualize the meaning of complex class numbers, and to ensure the completeness and accuracy of the documents retrieval by the UDC classes.
The universal droop control (UDC) can be applied to power inverters having an impedance angle between -pi/2 rad and pi/2 rad to achieve voltage and frequency regulation and accurate proportional ...power sharing without the need of knowing the type or value of impedance. However, there is an increasing need for voltage and frequency regulation within predetermined ranges even under some abnormal conditions, such as overloading, sensor faults, and large set-point changes, etc. In this paper, a bounded nonlinear dynamics is introduced into the UDC to ensure that the voltage and frequency can always stay within predetermined ranges under normal and some abnormal conditions, up to hardware limits when current protection needs to be triggered. As a result, the proposed controller can extend the operational range of power inverters in terms of voltage and frequency regulation to cover different scenarios. More importantly, the ranges for both voltage and frequency can be chosen independently from each other. Since the original structure of the UDC is kept in the proposed controller, the properties of the UDC, such as without the need of knowing the type or value of impedance, are well maintained. Furthermore, the closed-loop stability of the system is established via the Lyapunov method. Extensive simulation and experimental results are presented to validate the effectiveness of the proposed controller.
7‐1: Invited Paper: UDC Technology for OLED Display Lou, Jun-hui; Zhang, Lu; Ge, Lin
SID International Symposium Digest of technical papers,
June 2022, 2022-06-00, 20220601, Letnik:
53, Številka:
1
Journal Article
Recenzirano
UDC (Under‐Display Camera) technology is a technology breakthrough that can most likely solve the contradiction between the display integrity and front camera. It can improve the integrity of the ...display and the proportion of display screen. This paper analyzes the difficulties and challenges of the UDC technology, presents the progress of each key technical point and explores potential solutions. In the end, the paper introduces the UDC technology development and productions in Visionox Company.
The back-of-the-book index is, in spite of its importance, often regarded as an ornamental supplement to a book. In an attempt to criticize this view, INFOSTA Special Interest Group ...“Classification/Thesaurus/Indexing” made indexes for three books of general interest. The participants were divided into three groups, each addressing one of the books. While conventional indexes were constructed for two of the books, the content of the other one was represented by UDC numbers corresponding to its individual sections. Discussion on various issues on book indexes, including selection criteria for index entry terms and relationship of text words with index headings, yielded findings useful also in indexing of scientific papers or design of database indexes.
•A mechanistic under-deposit corrosion dynamic risk model is proposed.•The dynamic risk model is built upon using Dynamic Bayesian Network (DBN) approach.•The proposed model assesses the asset ...failure probability over five years of continuous operation.•Application of the model consistently confirm the failure probabilities data reported by the oil and gas industry.•The model serves as an important tool for inspection and maintenance planning.
This paper develops theoretical and mechanistic aspects of under-deposit corrosion (UDC) into a dynamic model and compares UDC progression and mitigation with current industrial practices. A Dynamic Bayesian Network (DBN) model is developed to understand different risk factors and their interdependencies in UDC and how the interaction of these risk factors leads to asset failure due to UDC. The DBN uses available UDC theory and transforms it into a probabilistic framework. The study compares DBN results from the general theory of UDC (based on the theory and mechanism of UDC) to industrial practices. The corrosion mechanism is represented in a Bayesian probabilistic framework involving solid deposits, flow velocity, operating pressure, under-deposit galvanic cell, chloride, pH, partial pressure of CO2, mono-ethylene glycol, and operating temperature. The Monte Carlo simulation (MCS) is used to characterize the stochastic properties of UDC. The proposed model assesses the asset failure probability over five years of continuous operation. DBN results show that they are consistent with failure probabilities data reported by the industry. Results also reveal that the pipeline wall thickness, outer pipe diameter, tensile strength, and operating pressure are critical contributors to UDC rate and asset failure likelihood. The results of this study are crucial for the inspection and maintenance schedule of pipelines affected by UDC.
PDF
