ADAPTIVE COORDINATION OF DISTANCE PROTECTION ON SUBTRANSMISSION LINES CONSIDERING THE INFEED EFFECT

ABSTRACT: This article describes an algorithm for an adaptive distance protection in a sub-transmission system considering operating conditions with changes in the topology due to an abnormal condition, electrical failure or a natural disaster, includes the effect of adjacent generation in the distance relay protection zones, with the incorporation of renewable energies in mixed participation. Two scenarios are proposed, in the first case occurred a contingency, and the transmission systems changes the initial topology. Protections are automatically reparametrized. The second case includes the income of renewable energy generation in a specific point of power electrical Systems. Protections are automatically recalculated. The objective of an automatic coordination permit to operator to restore the sensitivity, selectivity and reliability the electrical protection system in the lowest time. Keywords: Adaptive distance relay, renewable energy, distance protection, infeed effect..)

Penumbra in acute ischemic stroke

Acute ischemic stroke is one of the leading causes of disability and death worldwide. The brain tissue adjacent to the central necrotic core was first defined as ischemic penumbra characterized by reduced cerebral blood flow (CBF) with electrical failure but maintained ionic homeostasis and transmembrane electrical potentials. Since then, the evolving concepts of the ischemic penumbra have been proposed based on energy metabolism, CBF thresholds and protein synthesis, which provide insight for the diagnosis and treatment of acute ischemic stroke. This paper summarizes the recent advances in the understanding of ischemic penumbra, from its discovery to the diagnosis methods based on imaging techniques and biomarkers, finally some of the treatments developed. In addition, we discussed future perspectives on therapeutic targets beyond ischemic penumbra to develop a treatment for acute ischemic stroke.

Accelerated and Outdoor Weathering of Silver Nanowire Transparent Conductors under Electrical Stress in Pseudo-modules

In realistic applications, silver nanowires (AgNWs) are encapsulated in optoelectrical devices to function as transparent conductors and electrodes. Environmental stressors along with the essential electrical stress are inevitably harmful to the AgNWs inside the devices. Herein, to investigate the degradation behavior discrepancy between materials-level and device-level tests, we adopted pseudo-module to mimic the encapsulation. The pseudo-module allows the application of electrical stress and facilitates the interim specimen access for materials characterization through assembly-disassembly. Indoor accelerated and outdoor weathering tests with applied electrical stress to the pseudo-module encapsulated AgNW networks were performed. The impaired optoelectrical properties and morphological changes of AgNWs due to multiple or individual stressor(s) are investigated. Results indicate UVA exposure at elevated temperature coupled with electrical stress is responsible for the electrical failure of AgNW networks. Sulfidation that depresses optical transparency of AgNW networks is prone to occur at lower temperature. This work provides unambiguous degradation behaviors of AgNWs inside encapsulants, helping to improve the design of AgNWs related optoelectrical devices in the applications of solar irradiation environments.

Modeling and control of hybrid MR seat damper and whole body vibration evaluation for bus drivers

This paper describes the design, simulation, and performance evaluation of hybrid MR damper on quarter bus semi-active seat suspension coupled with human biodynamic model. Also, the whole body vibration (WBV) exposures were evaluated based on the international standard ISO 2631 (1997), and its parameters were used to measure the level of discomfort for bus drivers. The hybrid MR damper was proposed to enhance the damping force within low current supplied and achieve a fail-soft capability in case of electrical failure. The characteristics of the proposed hybrid MR damper were compared to the conventional MR damper by considering the same size, materials, and current input. The designed damper was incorporated to seat suspension system coupled with biodynamic lumped model, and the governing equations of motion of the full model were derived. Skyhook controller was used to control the amount of current to be supplied to hybrid MR damper. The controlled semi-active hybrid MR and conventional MR seat suspension are compared to uncontrolled system for two types of road excitation. The simulated results show that the driver seat comfort was improved by the skyhook controller than the uncontrolled case. The evaluated WBV showed that the hybrid MR damper can improve the driver life from fairly uncomfortable to little discomfort.

Analysis and Treatment of Electrical Fault of Ship Windlass

This paper aims at the electrical failure of the ship anchor machine, the potential causes of the failure are summarized and summarized by analyzing the electrical principle of the anchor machine. After the on-site failure investigation, the cause of the failure is accurately located, so as to put forward a feasible plan for the use and daily maintenance of the ship anchor machine. Because of its simple structure, stable operation and easy maintenance, the anchor machine is used for anchoring and maintenance of ships. Port docking is very important for ship safety and is widely used on ships.

Fuzzy - Based Multi - Criteria Decision Support System for Maintenance Management of Wastewater Treatment Plants

Wastewater treatment plants (WWTPs) contain a large number of components, and these components in turn require a large number of maintenance activities and high costs. In this paper, a Fuzzy-based Multi-Criteria Decision Support System (FBMCDS) model was designed based on the failure mode and effect analysis FM-EA and applied to the Rustumiya Project (RP) in Iraq. Information of the RP’s components, failure modes, applied maintenance activities and costs were collected from the documented data, site visit and face-to-face interviews as well as opinions of 44 experts. Through applying the fuzzy logic to analysis the failure modes and effects, the risk priority index (FMRPI) and total intensity (FMTI) of each failure mode ware computed. Thus, maintenance priorities and weights of the RP’s failure modes were specified. In addition, the best maintenance plan was specified based on the FMRPI-FMTI diagram that shows the importance and the type of maintenance required for each failure mode. Failure of the submersible pump has the first rank in terms of priority, while the last priority was occupied by the building failure mode, where the mechanical failure modes are of the highest importance, followed by the electrical failure modes. Finally, the construction failure modes are ranked last due to the small probability of failure. The designed model is considered an efficient tool due to the similarity of the results with the reality of the situation and the ease of reading and displaying the results. In addition, this model can be applied to other projects such as water treatment plants and irrigation projects.

SRAM Bitcell Defect Identification Methodology Using Electrical Failure Analysis Data

Static Random Access Memory (SRAM) has long been used for a new technology development vehicle because it is sensitive to process defects due to its high density and minimum feature size. In addition, failure location can be accurately predicted because of the highly structured architecture. Thus, fast and accurate Failure Analysis (FA) of the SRAM failure is crucial for the success of new technology learning and development. It is often quite time consuming to identify defects through conventional physical failure analysis techniques. In this paper, we present an advanced defect identification methodology for SRAM bitcell failures with fast speed and high accuracy based on the bitcell transistor analog characteristics from special design for test (DFT) features, Direct Bitcell Access (DBA). This technique has the advantage to shorten FA throughput time due to a time efficient test method and an intuitive failure analysis method based on Electrical Failure Analysis (EFA) without destructive analysis. In addition, all the defects in a wafer can be analyzed and improved simultaneously utilizing the proposed defect identification methodology. Some successful case studies are also discussed to demonstrate the efficiency of the proposed defect identification methodology.

SRAM Bitcell Defect Identification Methodology Using Electrical Failure Analysis Data

Static Random Access Memory (SRAM) has long been used for a new technology development vehicle because it is sensitive to process defects due to its high density and minimum feature size. In addition, failure location can be accurately predicted because of the highly structured architecture. Thus, fast and accurate Failure Analysis (FA) of the SRAM failure is crucial for the success of new technology learning and development. It is often quite time consuming to identify defects through conventional physical failure analysis techniques. In this paper, we present an advanced defect identification methodology for SRAM bitcell failures with fast speed and high accuracy based on the bitcell transistor analog characteristics from special design for test (DFT) features, Direct Bitcell Access (DBA). This technique has the advantage to shorten FA throughput time due to a time efficient test method and an intuitive failure analysis method based on Electrical Failure Analysis (EFA) without destructive analysis. In addition, all the defects in a wafer can be analyzed and improved simultaneously utilizing the proposed defect identification methodology. Some successful case studies are also discussed to demonstrate the efficiency of the proposed defect identification methodology.

Universal Application of Load Board (L/B) and Socket with Direct Current Tester (DCT) for Various Packages

We develop a new workflow with O/S tester (Direct Current Tester, DCT) to detect quickly the defect location of failure packages, which can be used in the semiconductor industry for E-FA (Electrical Failure Analysis) fault localization for short, leakage, and open defects. This paper introduces the capability and presents two case studies identifying the defect location of solder balls where DCT with defect mapping function is useful as a non-destructive analysis technique. In this paper, the new methodology and application of DCT on open and short defects in various packages with different sizes have been presented. The experimental results of the design testing program and an intender tooling were verified for the accuracy of the defect mapping function in determining the pin location to defect.