Analysis of High Impedance Protection Considering CT-Transients and Air Gapped CTs with Setting Recommendations and a New Fast Acting Algorithm for High Impedance Numerical Relays

2011 ◽  
Vol 12 (1) ◽  
Author(s):  
Abhishek Khanna
Keyword(s):  
Operating Time ◽  
Operation Time ◽  
Clearance Time ◽  
High Impedance ◽  
Fault Currents ◽  
The Poor ◽  
Set Up ◽  
Fault Clearance ◽  
Fast Acting ◽  
New Algorithms

This paper scrutinises the present day setting practice for the high impedance type relay and the associated CT dimensioning. It is demonstrated that the present day practice for setting and CT dimensioning can cause delay in the relay operating time particularly if the CTs have residual flux in the direction of flux set up by the fault currents. The paper suggests methods to reduce the relay operation time and the fault clearance time by using the anti remanance CTs. Setting methodology for the anti-remanance CTs is also proposed. To overcome the delay in relay operation due to the poor transient response of the iron cored CTs, two new algorithms are proposed. These algorithms are simple and easily implementable in the numerical relays and can be used in systems where relay replacement is much easier than CT replacement. The concepts proposed in the paper are demonstrated by simulations using non linear mathematical models of CT and surge arrestors.

EFFECT OF OPERATING TIME OF THE WELLS IN THE STEADY DRAINAGE MODE BEFORE STOPPING ON THE RESULTS OF THE STUDY OF PRESSURE BUILD-UP CURVES

2017 ◽  
pp. 48-50
Author(s):  
E. F. Gilfanov
Keyword(s):  
Operating Time ◽  
Previous History ◽  
Operation Time ◽  
Pressure Recovery ◽  
Recovery Curve ◽  
History Of ◽  
Accuracy Of Results ◽  
Theoretical Pressure

Operation time of the well before stopping for investigating the pressure recovery curve in hydrodynamic studies is an important parameter affecting the quality and accuracy of results of research processing. Comparing the actual and theoretical pressure curves and the derivative, it’s possible to eliminate the uncertainty in the choice of previous history of the well operation.

L'uretere retrocavale: Embriogenesi e correzione laparoscopica con accesso retroperitoneale in un caso ad ansa bassa

1997 ◽  
Vol 64 (1_suppl) ◽  
pp. 18-22
Author(s):  
C. Trombetta ◽  
G. Savoca ◽  
G. Liguori ◽  
M. Raber ◽  
A. Lissiani ◽  
...  
Keyword(s):  
Operating Time ◽  
Oral Intake ◽  
Operation Time ◽  
Ureteral Stent ◽  
Surgical Wound ◽  
Extraperitoneal Approach ◽  
Intravenous Urogram ◽  
Minimal Morbidity ◽  
Urologic Surgery ◽  
Laparoscopic Techniques

With the minimal morbidity attained using laparoscopy, its application in urologic surgery has been increasing. Using laparoscopic techniques we successfully completed the transposition and re-anastomosis of a retrocaval right ureter. Operation time was 240 minutes. The patient was allowed to walk on the first post-operative day and resumed oral intake on the second day. Administration of analgesics was not required. The ureteral stent was removed on the 24th day after operation. An intravenous urogram three months after operation showed a decrease in hydronephrosis. Laparoscopic correction of retrocaval ureter by extraperitoneal approach is a safe, feasible technique, avoiding a large surgical wound with the definite advantage of minimal disfigurement. Operating time is considerably shorter compared to the peritoneal approach as described by Baba (240’ vs 560’).

scholarly journals An Equivalent Circuit for the Evaluation of Cross-Country Fault Currents in Medium Voltage (MV) Distribution Networks

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1929 ◽  
Author(s):  
Fabio Gatta ◽  
Alberto Geri ◽  
Stefano Lauria ◽  
Marco Maccioni
Keyword(s):  
Distribution Networks ◽  
General Purpose ◽  
Simultaneous Occurrence ◽  
Medium Voltage ◽  
Electromagnetic Transient ◽  
High Impedance ◽  
Fault Currents ◽  
Cross Country ◽  
Return Path

A Cross-Country Fault (CCF) is the simultaneous occurrence of a couple of Line-to-Ground Faults (LGFs), affecting different phases of same feeder or of two distinct ones, at different fault locations. CCFs are not uncommon in medium voltage (MV) public distribution networks operated with ungrounded or high-impedance neutral: despite the relatively small value of LGF current that is typical of such networks, CCF currents can be comparable to those that are found in Phase-To-Phase Faults, if the affected feeder(s) consists of cables. This occurs because the faulted cables’ sheaths/screens provide a continuous, relatively low-impedance metallic return path to the fault currents. An accurate evaluation is in order, since the resulting current magnitudes can overheat sheaths/screens, endangering cable joints and other plastic sheaths. Such evaluation, however, requires the modeling of the whole MV network in the phase domain, simulating cable screens and their connections to the primary and secondary substation earth electrodes by suitable computer programs, such as ATP (which is the acronym for alternative transient program) or EMTP (the acronym for electromagnetic transient program), with substantial input data being involved. This paper presents a simplified yet accurate circuit model of the faulted MV network, taking into account the CCF currents’ return path (cable sheaths/screens, ground conductors, and earthing resistances of secondary substations). The proposed CCF model can be implemented in a general-purpose simulation program, and it yields accurate fault currents estimates: for a 20 kV network case study, the comparison with accurate ATP simulations evidences mismatches mostly smaller than 2%, and never exceeding 5%.

scholarly journals Urban Poverty and Vulnerability: Literature and Perspective

2021 ◽  
Vol 5 (9) ◽  
pp. 12-18
Author(s):  
Shilpa Deo*
Keyword(s):  
Poverty Alleviation ◽  
Task Force ◽  
Urban Poverty ◽  
Research Papers ◽  
The Poor ◽  
Poverty Elimination ◽  
The Government ◽  
Set Up ◽  
The Needy ◽  
Measurement Of Poverty

The Government of India has been taking various steps towards identification of the poor (and vulnerable through the Socio Economic Caste Census) and measurement of poverty with the help of various Expert Groups right from the Task Force that was set up in 1962 to the Task Force on Poverty Elimination of the NITI Aayog. There have been many researchers as well who have been suggesting the ways in which the poor and vulnerable can be identified and poverty can be measured besides the suggestions given by the Expert Groups. However, it may be considered as a ‘national shame’ if we are unable to identify the needy even after 75 years of independence. Through the review of around 100 books, research papers and articles, an attempt has been to understand the strengths and shortcomings of suggested ways to identify the poor and vulnerable and suggest a comprehensive methodology to identify the needy. Unless we are able to identify the poor and vulnerable sections of society correctly, planning and implementing poverty alleviation programmes for “ending poverty in all its forms everywhere”1 would be a futile exercise!

Making Sense of a Quiet Revolution

2018 ◽  
pp. 3-18
Author(s):  
Lutz Leisering
Keyword(s):  
Global South ◽  
Cash Transfers ◽  
Cash Transfer ◽  
Social Citizenship ◽  
Georg Simmel ◽  
Making Sense ◽  
The Poor ◽  
Research Questions ◽  
Social Cash Transfers ◽  
Set Up

This chapter introduces the topic of the book, social cash transfers for the poor in the global South, and depicts the research questions, theories, methods, indicators, and data of the analysis. The research questions relate to what kind of social cash transfer programmes have been set up in the global South, how international organizations came to accept the concept and constructed models of cash transfers, what factors made for the global spread of cash transfers, and if cash transfers have brought social citizenship to the poor. Drawing on Georg Simmel, T. H. Marshall, John W. Meyer, and Franz-Xaver Kaufmann, the theoretical approach of the book combines sociological theories of social policy, constructivist institutionalism, and world society theory, to complement the dominant approaches from welfare economics and political economy. Research includes qualitative and quantitative data and methods, with a unique large N data set. A figure depicts the research plan of the book.

scholarly journals A Multilayer Genetic Algorithm for Automated Guided Vehicles and Dual Automated Yard Cranes Coordinated Scheduling

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Qianru Zhao ◽  
Shouwen Ji ◽  
Wenpeng Zhao ◽  
Xinling De
Keyword(s):  
Genetic Algorithm ◽  
Energy Consumption ◽  
Operating Time ◽  
Operation Time ◽  
Complex Model ◽  
Automated Guided Vehicles ◽  
Total Energy Consumption ◽  
Equipment Operation ◽  
Storage Location ◽  
Calculation Results

At present, a lot of studies on automatic terminal scheduling are aimed at the shortest operating time. An effective way to reduce the operating time is to increase the amount of operating equipment. However, people often ignore the additional costs and energy consumption caused by increasing the amount of equipment. This paper comprehensively considers the two aspects of the equipment operation time and equipment quantity matching. With the minimum total energy consumption of the operating equipment as the objective function, a cooperative scheduling model of Automated Guided Vehicles (AGVs) and dual Automated Yard Cranes (AYCs) is established. In the modelling process, we also considered the interference problem between dual Automated Yard Cranes (AYCs). In order to solve this complex model, this paper designs an improved multilayer genetic algorithm. Finally, the calculation results from CPLEX and a multilayer genetic algorithm are compared, and the effectiveness of the model and algorithm is proved by experiments. In addition, at the same time, it is proved that it is necessary to consider the interference problem of dual Automated Yard Cranes (AYCs), and the optimal quantity matching scheme for the equipment and the optimal temporary storage location is given.

“An Echo of the Multitude”: The Intersection of Governmental and Private Poverty Initiatives in Early Modern Exeter

2000 ◽  
Vol 32 (3) ◽  
pp. 408-428
Author(s):  
Connie S. Evans
Keyword(s):  
Early Modern ◽  
Voluntary Contributions ◽  
The Poor ◽  
Poor Families ◽  
Set Up ◽  
The City

On June 15, 1624, Dr. Robert Vilvane informed the mayor of Exeter by letter of his displeasure with the haphazard application of poor rates in the city. Vilvane, who owned property within the city and in the surrounding countryside, was protesting the high rates imposed on his modest holdings in the city, since he was already subject to what he felt were excessive assessments on his country properties. Vilvane pointed out that he had taken it upon himself to support the purchase of armor and powder for martial officers, along with voluntary contributions to the poor, to churches, and to “sundry other taxes.” Despite a debt to the city in the amount of £500 (on which he paid interest), he did “freely give 12d weekly to two poor families here, which else would fall into penury.” Having recounted all this, he considered that “there is little cause to hoist me so high to all payments, who (besides my house) have little here [in the city].” At the crux of his argument, he asserted, was “that a Rate to the Poor is no competent Rule…both because it is uncertain…and also unequal, because some are set up too high, and others too low, by fear or favour.” Vilvane had contributed to a certain collection for the poor in a particular part of the city and noted that “many murmur at this day” about the collection, since it appeared that the overseers “did not disburse above half the Contribution.” As an unwilling party to this scheme, the doctor was upset, as he felt others were: “[I] do profess myself in this but an Echo of the Multitude, which are much aggrieved.”

Rainwater propeller pumps structural integrity

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sergiu Valentin Galatanu ◽  
Sebastian Muntean ◽  
Liviu Marsavina ◽  
Iulian Ionut Ailinei ◽  
Dan Micota
Keyword(s):  
Shear Stress ◽  
Structural Integrity ◽  
Maximum Shear Stress ◽  
Operating Time ◽  
Operation Time ◽  
Technical Solution ◽  
Catastrophic Events ◽  
Impeller Blade ◽  
Content Type ◽  
Technical Solutions

Purpose The purpose of this paper is to focus on the structural integrity of the rainwater propeller pumps installed in the municipal wastewater treatment plant (WTP). Design/methodology/approach A numerical analysis is performed to determine the maximum shear stress on the fasten bolts. The rainwater propeller pump is examined in operation at normal conditions and when one blade is progressively blocked. Findings The failure mechanism of the rainwater pump impeller is determined. Research limitations/implications The fibbers and wastes are discharged together with rainwater during storms with these types of pumps to avoid the flood of the WTP. Several catastrophic events have occurred in service due to the fibbers clog the gap between the impeller blades and the pump casing. The clogging process is partially understood so actual technical solutions deal with effects rather the main causes. Practical implications The operation time of all seven rainwater pumps installed in Timisoara’s WTP is investigated. Climate changes in Banat region and new waste properties found in the wastewater require appropriate technical solutions. A technical solution is proposed based on these investigations to extend the operation time and to diminish the operation and maintenance costs. Social implications These large pumps are installed in the urban sewage centralised system implemented in the most cities. The access to the sewerage network is a requirement of any community, regardless of the social status. Originality/value The fracture surfaces of both fastening bolts of the rainwater pump impellers produced in service are examined. As a result, it has been identified that the catastrophic events are due to the brittle fracture of both fasten bolts between the impeller blades and the pump hub, respectively. The catastrophic events of the rainwater propeller pumps are directly correlated to the clog level of the impeller. The numerical simulation is performed to determine the maximum shear stress on the fasten bolts. The case with pump operating at normal conditions is performed identifying its vulnerabilities to clog conditions. Next, one impeller blade is progressively blocked considering three time stop scenarios associated with different clog levels. Conclusively, the operating time of the rainwater pump up to the catastrophic failure is correlated to the clog level of the impeller.

scholarly journals The Price of Poverty: Policy Implications of the Unequal Effects of Monetary Sanctions on the Poor

2020 ◽  
Vol 37 (1) ◽  
pp. 45-65
Author(s):  
Ilya Slavinski ◽  
Kimberly Spencer-Suarez
Keyword(s):  
United States ◽  
New York ◽  
Low Income ◽  
The United States ◽  
Policy Implications ◽  
Federal State ◽  
The Poor ◽  
Time Requirements ◽  
State And Local ◽  
Set Up

Over the last several decades, with the rise of mass incarceration in the United States and its steep costs, governments at the federal, state, and local levels have dramatically ramped up monetary punishment. Monetary sanctions are now the most common type of criminal penalty in the United States. The growth of fines, fees, and other legal financial obligations (LFOs), and the ensuing legal debt, reflect a shifting of the system’s costs onto its primarily low-income and indigent subjects. This study provides an exploration of previously underexamined ways in which monetary sanctions impose distinct burdens on the poor. Interviews with 121 defendants in Texas and New York, along with courtroom observations, demonstrate that criminal legal debt is particularly challenging for people with low incomes in three meaningful ways. First, systems set up to handle indigency claims do not adequately address the needs or complex individual circumstances of those who simply do not have the ability to pay. Oftentimes, alternatives are unavailable or statutorily prohibited. Second, the lack of alternatives to payment lead to compromising situations, which then compel indigent defendants to make difficult choices about how to allocate scant resources. Finally, being encumbered with fines and fees and participating in alternatives like community service comes with taxing time requirements that can prove uniquely challenging for those who are poor. These three findings lead us to propose a series of policy recommendations revolving around three key themes: (a) enhancement of indigency procedures, (b) equity in monetary sanctions, and (c) alleviating burdens by improving accessibility.

scholarly journals Endoscopic, Single-Session Management of Encrusted, Forgotten Ureteral Stents

Medicina ◽  
2019 ◽  
Vol 55 (3) ◽  
pp. 58 ◽  
Author(s):  
Volkan Ulker ◽  
Orcun Celik
Keyword(s):  
Hospital Stay ◽  
Treatment Options ◽  
Operating Time ◽  
Operation Time ◽  
Ureteral Stents ◽  
Single Session ◽  
Extracorporeal Shock Wave ◽  
Clavien Grade ◽  
Grade Ii ◽  
The Mean

Background and Objectives: Remained or forgotten ureteral double-J stents may cause serious complications. Removing of an encrusted, forgotten stent can be challenging. We present our experience with heavily encrusted ureteral stents and discuss the endourologic treatment options as well as their effectivity. Materials and Methods: Eleven men and six women (mean 48.58 ± 14.48 years of age) with 18 encrusted forgotten stents (mean 16.4 ± 13.25 months of indwelling) were treated at our clinic. All patients underwent the operation after negative urine cultures were obtained. Their medical records were retrospectively reviewed and analyzed in terms of number of interventions required to remove the stent, operation time, complications, hospital stay and stone-free rate. Results: According to the Forgotten-Encrusted-Calcified (FECal) classification, the most common form of stent encrustation was grade III (64.7%) and 17.6% of the stents were fragmented. Four of 17 patients were initially treated with extracorporeal shock-wave lithotripsy. The patients required a mean of two endoscopic interventions for removing the encrusted stent and all stents were removed endoscopically in a single session. The mean operating time was 63.3 ± 41.8 minutes. Cystolithotripsy followed by ureteroscopy was the most common intervention (41.1%). Of the 17 patients, peroperative and postoperative complications were Clavien grade I in two, grade II in two and grade IIIb in one. The mean hospital stay was 1.3 ± 0.99 days. All patients were stone-free after a month of stent removal. Conclusions: The endourological removal of the encrusted forgotten stents in a single session is feasible and effective with a minimal morbidity. The treatment strategy should be to minimize the number of interventions.

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