Main Feeder Research Articles

Embolization of midbrain arteriovenous malformation fed by the artery of Percheron in a child, the first case report and literature review.

Artery of Percheron (AOP) as main feeder artery of arteriovenous malformation (AVM) is extremely rare. Two cases of thalamic AVM fed by AOP have been reported to date and only one AVM been removed by microsurgery when attempt of intervention embolization failed. Midbrain AVM fed by AOP has not been reported yet. Here, we presented the first successful embolized case of midbrain AVM supplied by the AOP in a 10-year-old boy, who suffered dual oculomotor nerve palsy and secondary hemorrhage before embolization. During endovascular embolization, selective angiography by 1.2 Fr. Magic microcatheter showed an intranidal aneurysm located on the distal AOP. Two injections of a 1:4 ratio mixture of NBCA-MS completely occlude the nidus and intranidal aneurysm with no complications occurred. The child recovered well and the oculomotor deficits improved. This case highlighted that AOP is a clinically significant branch associated with AVM in midbrain and thalamus. Moreover, intervention embolization of midbrain AVM fed by AOP is a considerable therapeutic strategy.

VARIATION OF SOME WATER QUALITY PARAMETERS OF HUWAIZA MARSH IN SOUTHERN IRAQ

Huwaiza marsh is considered the largest marsh in the southern part of Iraq. It is located between 31° and 31.75° latitude and extends over the Iraqi-Iranian border; but the largest part lies in Iraq. It is located to the east of Tigris River in Messan and Basra governorates.In this research, the variation of some water quality parameters at different locations of Huwaiza marsh were studied to find out its efficacy in the treatment of the contamination coming from the wastewater outfall of Kahlaa brokendown sewage treatment plant which lies on the Kahlaa River. This rive is the main feeder of Huwaiza marsh. Ten water quality sampling locations were chosen in this marsh. The water samples were taken during 2009 for three months; January, April and August representing winter, spring and summer respectively.The results of water quality analyses showed that Kahlaa untreated sewage had a negative impact on the water quality of Huwazia marsh; especially in its upstream region. Analyses of water samples taken from the middle and downstream end of the marsh showed that the marsh water is safe for fishing and swimming in these regions.

A Method for Assessing the Feasibility of Integrating Planned Unidirectional EV Chargers into the Distribution Grid: A Case Study in Danang, Vietnam

The journey towards transportation electrification started with electric vehicles and has attracted more and more attention on a global scale in recent years. EVs are seen as a substantial, effective, and urgent solution for transportation electrification. In this paper, we investigate the operation requirements for integrating charger stations into the distribution grid in Vietnam. We also propose a simple evaluation method for assessing the feasibility of integrating planned unidirectional EV chargers into the distribution grid. The assessment method is applied to two main distribution feeders in Danang, Vietnam, where the new charger stations are already planned to be deployed in 2025 and 2030. The results showed that with addition of pre-planned EV chargers, both feeders still meet operation requirements in 2025 and 2030. However, the feeder with voltage indices close to the limit needs to be considered for an upgrade in configuration.

Intramuscular hemangioma presenting as pathological femur fracture: A case report

Hemangioma is a common benign soft-tissue tumor; however, intramuscular hemangioma presenting with a pathological fracture is an infrequent occurrence. Imaging plays a key role in diagnosing this entity. We report a case of a 30-year-old male who presented with a pathological fracture of the left femur following trivial trauma. Clinical examination was remarkable for a significant soft-tissue swelling which on further radiological investigation revealed a soft-tissue mass lesion in the left thigh muscles having multiple vascular channels and phleboliths extending into femoral cortex and medulla causing a pathological fracture. Diagnosing it as an aggressive hemangioma, the main feeder artery was embolized by polyvinyl alcohol particles. The patient is on traction and follow-up. Intramuscular hemangioma causing pathological fracture is extremely rare. Understanding the typical and atypical radiological findings of an intramuscular hemangioma will impede misdiagnosis, and unnecessary tissue sampling, and allow for expedited and appropriate management.

Effect of Fiber Side-Feeding on Various Properties of Nickel-Coated Carbon-Fiber-Reinforced Polyamide 6 Composites Prepared by a Twin-Screw Extrusion Process

In the present study, how side-feeding of NiCF during twin-screw extrusion processing influences the fiber aspect ratio and thermal, mechanical, electrical, and electromagnetic properties of nickel-coated carbon fiber (NiCF)-reinforced polyamide 6 (PA6) composites was explored. For this, the fiber length distribution, thermal stability, heat deflection temperature, dynamic mechanical property, tensile, flexural, electrical resistivity, and electromagnetic interference shielding effectiveness (EMI SE) properties of NiCF/PA6 composites were extensively investigated. Chopped NiCF was regularly fed via either a main feeder or a side feeder and NiCF/PA6 pellets with different fiber-feeding pathways were prepared. The side-feeding effect of NiCF on the fiber length distribution and the composite properties was studied. The thermal stability, heat deflection temperature, storage modulus, tensile, flexural, and surface resistivity, and EMI SE properties of the NiCF/PA6 composites strongly depended not only on the NiCF content but also on the feeding method (main-feeding or side-feeding) upon extrusion processing, indicating that the fiber length distribution relevant to the fiber aspect ratio was critically important to enhance the composites’ properties. As a result, the NiCF/PA6 composites produced via side-feeding of NiCF exhibited an NiCF distribution longer than that produced via main-feeding, leading to enhancement of the thermal stability, heat deflection temperature, storage modulus, tensile, flexural, and EMI SE properties, strongly depending on the NiCF content.

Adaptive OCR coordination in distribution system with distributed energy resources contribution

<abstract> <p>More and more distributed energy resources (DERs) are being added to the medium-voltage (MV) or low-voltage (LV) radial distribution networks (RDNs). These distributed power sources will cause the redistribution of power flow and fault current, bringing new challenges to the coordination of power system protection. An adaptive protection coordination strategy is proposed in this paper. It will trace the connectivity of the system structure to determine the set of relay numbers as a tracking path. According to the topology of the system structure, the tracking path can be divided into two categories: the main feeder path and the branch path. The time multiplier setting (TMS) of each relay can be used to evaluate the operation time of the over-current relay (OCR), and the operation time of the relay can be used to evaluate the fitness of the TMS setting combination. Furthermore, the relay protection coordination problem can be modeled to minimize the accumulated summation of all primary and backup relay operation time (OT) subject to the coordination time interval (CTI) limitation. A modified particle swarm optimization (MPSO) algorithm with adaptive self-cognition and society operation scheme (ASSOS) was proposed and utilized to determine TMS for each relay on the tracking path. A 16-bus test MV system with distributed generators (DGs) will be applied to test the adaptive protection coordination approach proposed in this paper. The results show that the proposed MPSO algorithm reduces the overall OT and relieves the impact on protection coordination settings after DG joins the system. The paper also tests and compares the proposed MPSO with other metaheuristic intelligence-based random search algorithms to prove that MPSO possesses with increased efficiency and performance.</p> </abstract>

A Novel Compact High Gain Wide-Band Log Periodic Dipole Array Antenna for Wireless Communication Systems

This paper implies a prototype for a broad-band log periodic dipole antenna (LPDA) with dimensions of 20 × 40 × 0.508 mm3 equipped with directors. The LPDA is based on Roger’s RT5880 with εr = 2.2. The 4-arms with alternative stubs constitute the LPDA, which is evenly spaced on both lines. At the substrate’s back, the 50Ω main feeder line is placed on partial ground. The directors are also incorporated and studied in a regular matrix at a predetermined distance to improve gain, further reduce side lobes, and widen the frequency band. The performance of the antenna covers a wide spectrum of millimeter waves ranging from 26 up to 44 GHz. The realized gain for the antenna is 8.97, 11.96, 13.96, and 14.29 dB at 28 GHz, 35 GHz, 38 GHz, and 43 GHz, respectively. The total gain is 14.29 dB as a peak gain. The antenna was designed and tested for 5G communication applications in autonomous vehicles, and the design cost for the antenna is low in comparison to dielectric lenses. The model exhibits symmetrical radiation patterns for the antenna range. The results of the simulations and the testing of the implemented antenna elements coincide quite well. The proposed design outperforms earlier work in this field.

The Polish Version of the Avoidant/Restrictive Food Intake Disorder Questionnaire-Parents Report (ARFID-Q-PR) and the Nine Items Avoidant/Restrictive Food Intake Disorder Screen-Parents Report (NIAS-PR): Maternal Perspective.

The aim of the present study was to develop and validate the Avoidant/Restrictive Food Intake Disorder Questionnaire—Parents Report (ARFID-Q-PR), a new tool to diagnose ARFID, based on a report submitted by Polish mothers of children aged 2 to 10 years. In total, 167 mothers of boys and girls aged 2 to 10 participated in the study. We used the ARFID-Q-PR and the Nine Items Avoidant/Restrictive Food Intake Disorder Screen—Parents Report (NIAS-PR). In addition, all mothers were asked to provide information on age, sex, height and weight, chronic somatic diseases, neurodevelopmental and mental disorders as well as intellectual disability of their children. Results of the reliability analysis demonstrated that the ARFID-Q-PR had adequate internal consistency (Cronbach’s alpha of 0.84). The stability of the ARFID-Q-PR factorial structure was confirmed. It is composed of three subscales: (1) attitudes to food; (2) justification for restrictions; (3) somatic symptoms. Our findings demonstrated that the ARFID-Q-PR total score was positively associated with the NIAS-PR total score. In addition, children with developmental and mental disorders substantially demonstrated more ARFID symptoms than did the children in the general population. The Polish version ARFID-Q-PR can be used to recognize the ARFID symptoms in young children by the main feeder in the family—mother or father.

Connecting people and places: Analysis of perceived pedestrian accessibility to railway stations by Bavarian case studies

Walking connects different modes of transport and acts as the main feeder for public transport. Nonetheless, ensuring high-quality accessibility for pedestrians to railway stations is seldom evaluated beyond measurable factors such as walking distance and time. Although several studies found differences in calculated and perceived accessibility, little research has so far focused on the factors that are influencing perceived pedestrian accessibility and thus causing these differences. In order to contribute to the current efforts of conceptualizing perceived accessibility, this study explores the factors which determine whether or not people walk to train stations. Potential influencing factors were first derived from a literature review and clustered into six quality criteria (directness, simplicity, traffic safety, security, comfort and built environment). Then, on-site and online surveys were conducted in five Bavarian towns (Germany) to understand the importance of the identified factors and how this differs between different people and places. The results confirm that above all comfort, safety and security factors play an important role for pedestrian accessibility. In addition, significant differences were found between different age groups and city sizes.

Non-invasive angiographic analysis of dural carotid cavernous fistula using time-of-flight MR angiography and silent MR angiography: a comparative study.

A non-invasive, reliable imaging modality that characterizes cavernous sinus dural arteriovenous fistula (CSDAVF) is beneficial for diagnosis and to assess resolution on follow-up. To assess the utility of 3D time-of-flight (TOF) and silent magnetic resonance angiography (MRA) for evaluation of CSDAVF from an endovascular perspective. This prospective study included 37 patients with CSDAVF, who were subjected to digital subtraction angiography (DSA) and 3-T MR imaging with 3D TOF and silent MRA. The main arterial feeders, fistula site, and venous drainage pattern were evaluated, and the results were compared with DSA findings. The diagnostic confidence scores were also recorded using a 4-point Likert scale. Silent MRA correlated better for shunt site localization and angiographic classification (86% vs. 75% and 83% vs. 75%, respectively) compared to TOF MRA. The proportion of arterial feeders detected was marginally significant for silent MRA over TOF MRA sequences (92.8% vs. 89.5%; P=0.048), though for veins both were comparable. Sensitivity of silent MRA was higher for identification of cortical venous reflux (CVR) (90.9% vs. 81.8%) and deep venous drainage (82.4% vs. 64.7%), while specificity was >90% for both modalities. The overall diagnostic confidence score fared better for silent MRA for venous assessment (P < 0.001) as well as fistula point identification (P < 0.001), while no significant difference was evident with TOF MRA for arterial feeders (P=0.06). Various angiographic components of CSDAVF could be identified and delineated by 3D TOF and silent MRA, though silent MRA was superior for overall diagnostic assessment.

Linear Programming Coordination for Overcurrent Relay in Electrical Distribution Systems with Distributed Generation

Electric power distribution networks are generally radial in nature, with unidirectional power flows transmitted from the highest voltage levels to the consumption levels. The protection system in these distribution networks is relatively simple and consists mainly of fuses, reclosers (RC) and overcurrent relays (OCRs). The installation of distributed generation (DG) in a network causes coordination problems between these devices, because the power flows are no longer unidirectional and can flow upstream to the substation. For this reason, the work proposed here analyzes the most significant impacts that DG has on the protection devices and proposes an adjustment method for the OCRs based on linear programming (LP) techniques with the aim of improving their response time to the different faults that may occur in the main feeder of the network. The distribution system selected for the study is the IEEE 34 bus system using DIgSILENT 14.1 software for its modeling and Matlab for the adjustment of the overcurrent devices. Results indicate that better coordination between protection devices are achieved if LP is used.

Security Door Lock for Mains Supply and Safety of Electrical Engineer

The main motive of this work is to provide safety to the electrical field engineer who works on the site of main distribution line feeder box. To provide safety to the engineer, the feeder box is equipped with RFID sensor and RFID readers which plays an important role. The engineer will be provided authorized glows and shoes with RFID tags. The reader mounted on the box will check whether the glows are authorized or not. If it gets authorized, then only the main door of the box will open and engineer will do his work. When the door gets opened it will share the details to the main server of the electrical distribution office in the form of message “The door is open”. We have made the provision that it will help engineer to solve the issue after door opens. There will be one-way communication from distribution office to electrical field engineer regrading guidelines for the issues. We have also made an application to record the history of the problems in the data base which would help to identify problems in the future.

Forecast of Community Total Electric Load and HVAC Component Disaggregation through a New LSTM-Based Method

The forecast and estimation of total electric power demand of a residential community, its baseload, and its heating ventilation and air-conditioning (HVAC) power component, which represents a very large portion of a community electricity usage, are important enablers for optimal energy controls and utility planning. This paper proposes a method that employs machine learning in a multi-step integrated approach. An LSTM model for total electric power at the main circuit feeder is trained using historic multi-year hourly data, outdoor temperature, and solar irradiance. New key temperature indicators, TmHAVC, corresponding to the standby zero-power operation for HVAC systems for summer cooling and winter heating are introduced using a V-shaped hourly total load curve. The trained LTSM model is additionally run with TmHVAC and zero irradiance inputs yielding an estimated baseload, which is representative of typical occupancy patterns. The HVAC power component is disaggregated as the difference between total and baseload power. Total power forecasts of an aggregated residential community as seen by major distribution lines are experimentally validated with a satisfactory MAPE error below 10% based on a 4-year dataset from a representative suburban community with more than 1800 homes in Kentucky, U.S. Discussions regarding the validity of the separation method based on combined considerations of fundamental physics, statistics, and human behavior are also included.

Enhancing distribution system resiliency with microgrids formation using weighted average consensus

Integration of distributed energy resources (DERs) including renewable and storage, digital automation and the advanced metering infrastructure (AMI) provides an opportunity to further enhance resiliency during outage of main feeder. Access to local DERs with enhanced control ensures the sustainability of energy continuity to urban critical (vital) loads, by forming DER-based microgrids. Microgrid formation is challenging considering detecting failures; priority of loads; detecting location and boundary of load outages, while meeting the energy constraints and data sharing limitations to maximize resiliency. Consensus algorithms provide an opportunity to share data in limited manner but still allowing to reach consensus on the resource and network control for microgrids formation and enhance resiliency. In this work, a weighted average consensus mechanism has been proposed to detect failures due to faults and/or data loss and, hence, determine the isolated nodes as a first layer. Additionally, a mixed-integer linear programming (MILP) optimization problem is formulated and solved as part of the second layer to form the DER-based microgrids with the goal to improve the resiliency of the distribution system, while satisfying the consensus-based constraints. The proposed method is evaluated using the standard IEEE 123-node feeder. Simulation results demonstrate the effectiveness of the proposed weighted average consensus method in enhancing the distribution system resiliency by detecting failures and node isolation; and forming DER-based microgrids considering critical and non-critical loads.

Coexistence of anterior cranial fossa dural arteriovenous fistula and arteriovenous malformation with the same drainage system: illustrative case

BACKGROUNDThe authors report a rare case of coexistence of dural arteriovenous fistula (DAVF) and arteriovenous malformation (AVM), with a common trunk drainer from both DAVF and AVM in the left anterior cranial fossa (ACF) with simple DAVF in the right ACF.OBSERVATIONSA 63-year-old female presented with seizure. Cerebral angiography showed bilateral DAVFs in the ACF and AVM in the left frontal lobe. A dilated frontal vein acted as a simple drainer of the right DAVF. In contrast, a dilated vein with large varix was the common drainer of both the left DAVF and the AVM. During surgery, indocyanine green videoangiography was performed with direct observation. In the left ACF, the drainer occlusion of the DAVF resulted in partial shrinkage of the varix and decreased distal blood flow. Additional main feeder occlusion of the AVM could decrease the blood flow further, but not completely because of the residual pial supplies for the AVM. Finally, the nidus of the AVM with varix was removed by en bloc resection.LESSONSNeurosurgeons should be aware of the coexistence of DAVF and AVM with a common trunk drainer. Only simple occlusion of the drainer from DAVF is not sufficient, so removal of the AVM is essential.

Development of Pec Based Electrical Load Schedule Software

This paper presents the development of PEC-based electrical load schedule software for residential electrical services design. All the sources that will be used for the computation and data will be based on PEC. The testing of the project will be carried out in accordance with PEC as well as other approved codes. Calculating tools to help you understand the process of accurately sizing a commercial electrical panel based on proposed loads. To emphasize, accurate load sizing is best performed by an electrical engineer, which is reviewed by the building department in your jurisdiction. The software was developed using Visual Basic (VB. net) programming language. Vb.net, or Visual Basic, is a development of the BASIC programming language. It is intended to be used in conjunction with an Integrated Development Environment (IDE). Prior to the development of IDEs, programming languages like BASIC relied significantly on the DOS command-line. A load schedule for different operating scenarios will show when peak consumption occurs and provide an opportunity to find out if all the high loads must operate at this time. It serves as a valuable calculation tool for electrical engineers, students, and technicians by providing a faster, easier, and more accurate means of carrying out some basic calculations, such as determination of the size of wire; conduit sizes; circuit breaker ratings; the main feeder size of wires; main circuit breaker ratings; voltage drop; and riser diagram using Philippine Electrical Code Tables. The results of these calculations help the designer to make vital decisions such as cable sizing and nominal ratings of protective devices required by each circuit and by the entire installation, in line with appropriate standards and regulations.

Optimal Dispatching Strategy of Active Distribution Network for Promoting Local Consumption of Renewable Energy

Large-scale renewable energy sources (RESs) have been integrated into the active distribution network (ADN). For promoting the local consumption of RESs within ADN, an optimal dispatching strategy was proposed with two-stage hierarchical energy management framework. On the spatial boundary, a two-layer energy management framework was designed with the local optimization layer and the global optimization layer. The local optimization layer was for optimal power flow in the branch feeder with the objective functions of minimizing operation costs and maximizing the consumption of RESs. The global optimization layer was for optimal power flow in the main feeder with the objective functions of minimizing power loss and the voltage deviation of nodes. On the time scale, two-stage optimal dispatching models were established, including the day-ahead optimal models and intra-day optimal models. The day-ahead optimal models identified the operation status of the controllable units, and then the intra-day optimal models were updated with the ultra-short-term forecast results. A risk indicator was introduced to quantify the uncertainty of RES, and a non-dominated sorting genetic algorithm with elite strategy was adopted to solve the multi-objective nonlinear programming problem. An actual project in northern China was used as the testing system. The results of case studies verify that the proposed strategy can effectively realize the maximum local consumption of RESs and support the economic operation of ADN.

Impact of small hydro generation on voltage profile and losses in 20 kV distribution network

Planning in the development of electricity availability focuses on Renewable Energy power plants in support of the Government’s strong determination to suppress fossil-based energy and increase in New Renewable Energy whose mix is targeted to reach 23% in 2025. Distributed generation (DG) is one of the new approach in the installation of power plants which the plant location is no longer centralized, but it was spread on the distribution of electricity networks. Nowadays, the application of distributed generation has increased because it is a renewable energy especially small hydro of distributed power plants can affect the conditions of the distribution network. Therefore, it is necessary to know the impact of the installation of distributed power plants. This study was conducted to analyze the effects of DG connected to network at two conditions First, the distributed generation connect when under load condition in network and second, distributed generation connect when peak load condition in network. Simulation in this study was conducted using the ETAP software and The Newton-Raphson method has been used in order to calculate power losses and voltages across the network with real data of rural distribution network in Tanah Jawa, North Sumatera, Indonesia. The 20kV distribution network was used in this feeder, and it was divided into one main feeder. The results of this study are expected to provide information about the impact of the DG on voltage and power losses in distribution network. The results of the study show that the installation of DG enhances the voltage profile and ready for installation Small Hydro as DG.

Proportional‐integral‐derivative controller‐based self‐healing of distribution system using wireless sensor networks in smart grid

SummaryThe grid is a platform of distributing the power to the consumers; if an automatic controlling and monitoring are connected with the grid, it referred to as smart grid (SG). Self‐healing is the approach of restoring the unaffected areas without affecting the system performance. The term restoration is if a fault occurs on a distribution system, it must be isolated; after that, it can be reconfigured to restore the unaffected areas. The distribution system cannot work as efficient without the self‐healing approach because it will affect the unaffected areas without any proper reason. This paper proposed a multiagent system with controlled voltage (MAS‐CV) along with self‐healing of wireless sensor network (WSN) with proportional integral derivative (PID) controller in smart grid. At initial, the magnetic flux sensors are placed in the pole transformer for detection of flux leakage. The sensed data are transferred to the distribution grid, where the multiagent system (MAS) is established to carrying out the load restoration process (i.e., self‐healing). Connection agents (CA), monitor agent (MA), main feeder agent (MFA), backup feeder agent (BFA), supporting feeder agent (SFA), and local agent (LA) are the agents presented in the paper. Each agent is communicating via agent communication language (ACL) for the restoration process; after all the loads are restored, the voltage drop of the system is controlled by the proportional integral derivative controller. The simulation results of the proposed method show that the restoration of loads is improved and number of switching is reduced with improved data transmission. Thus, the cost of the proposed method is reduced by the reduced switches. At last, the controlled power from the distribution grid is send to the consumer.

Total laparoscopic resection by medial-retroperitoneal approach using virtual navigation: two case reports of primary retroperitoneal schwannoma

BackgroundWe report two rare cases of retroperitoneal schwannoma completely resected by a laparoscopic medial-retroperitoneal approach aided by virtual navigation. Three-dimensional images have been used in liver and lung surgery, but there are few prior reports on retroperitoneal surgery.Case presentationThese two case reports are of a 60-year-old man and a 40-year-old man with asymptomatic retroperitoneal schwannoma. In both cases, the tumors were located in the right renal hilum and were close to the duodenum, right ureter, and inferior vena cava. Simulation using three-dimensional images was performed before surgery, and a medial-retroperitoneal approach was performed to secure a wide surgical field. During the operation, we confirmed the location of the main feeder and the relationship between the tumor and organs with those shown on the three-dimensional images and performed total laparoscopic resection.ConclusionThe medial-retroperitoneal approach provides operative safety. Preoperative simulation and intraoperative navigation with three-dimensional images, which can be freely rotated and interactively visualized from any angle, are useful methods to enhance the surgeon’s understanding of a patient’s specific anatomy and are especially effective when resecting a retroperitoneal tumor that is located in an anatomically deep and complex location.