Application of a Specialized Passive Filter to Correct the Frequency Response of the Supply Network in order to Eliminate the Negative Impact of Resonance Phenomena

2020 ◽  
Author(s):  
A. A. Nikolaev ◽  
M. Yu. Afanasev ◽  
M. V. Bulanov
Keyword(s):  
Frequency Response ◽  
Negative Impact ◽  
Supply Network ◽  
Passive Filter ◽  
Resonance Phenomena

scholarly journals Overvoltages and Transients Identification In On-line Bushing Monitoring

2020 ◽  
Vol 69 (3) ◽  
Author(s):  
Wieslaw Gil ◽  
Wiktor Masłowski ◽  
Przemysław Wronek
Keyword(s):  
Frequency Response ◽  
Support Service ◽  
Monitoring Systems ◽  
Resonance Phenomena ◽  
Limited Frequency ◽  
On Line ◽  
High Dynamics

Overvoltages and transients are sometimes recognized as the cause of bushings’ rapid failure. This fact is confirmed by the studies published at the 2018 CIGRE session. They can also initiate dangerous resonance phenomena in transformer windings. The identification of very fast overvoltages characterized by high dynamics of voltage changes, so-called "transients", is difficult due to the limited frequency response of station voltage transformers. However, the bushing monitoring systems, based on the so-called "voltage method" can be used for this purpose successfully. There are several running bushing monitoring systems based on this method in Poland. The transients’ events are registered together with their oscillographs in Transformer Monitoring Systems (TMS). The overvoltage statistics are also performed to support service procedures.The TMS are integrated with station systems, which greatly increases the possibility of overvoltages phenomena analyzing.

scholarly journals Proof of Concept for the Detection of Local Pressure Marks in Prosthesis Sockets Using Structural Dynamics Measurement

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3821
Author(s):  
Constanze Neupetsch ◽  
Eric Hensel ◽  
Burkhard Kranz ◽  
Welf-Guntram Drossel ◽  
Thomas Felderhoff ◽  
...  
Keyword(s):  
Frequency Response ◽  
Structural Dynamics ◽  
Negative Impact ◽  
Residual Limb ◽  
Response Functions ◽  
Proof Of Concept ◽  
Local Pressure ◽  
Frequency Response Functions ◽  
Prosthetic Socket ◽  
Wear Comfort

The wear comfort of a prosthesis is of great importance for amputee patients. The wear comfort can be affected by changes in the interface between the residual limb and prosthesis socket, which can be caused by time-dependent volume fluctuations of the tissue, leading to unwanted local pressure marks. The basis to ensure time-independent wear comfort of a prosthesis is to identify these changes. Common techniques for identifying these variations have a negative impact on the sensitive interface between the residual limb and prosthesis. The following paper contains a proof of concept for the detection of local pressure marks without affecting the described interface using structural dynamics measurements, exemplarily shown at a prosthetic socket for transfemoral amputees in a test bench scenario. The dynamical behaviour of the investigated system is analysed in the form of frequency response functions acquired for different pressure locations and preloads using an impact hammer for excitation and a triaxial acceleration sensor. The frequency response functions show major changes for the various boundary conditions with respect to their frequency-dependent compositions. The results demonstrate how the utilised method enables the identification of changes in local pressure marks regarding the variation of position and magnitude.

scholarly journals Development of adaptive PWM algorithm for an active rectifier and a method for diagnosing resonant phenomena in in-plant networks

Vestnik IGEU ◽  
2020 ◽  
pp. 44-54
Author(s):  
A.A. Nikolaev ◽  
M.V. Bulanov ◽  
K.A. Shakhbieva
Keyword(s):  
Frequency Response ◽  
Power Supply ◽  
Frequency Converter ◽  
Resonance Region ◽  
Harmonic Series ◽  
Medium Voltage ◽  
Electric Drives ◽  
Frequency Converters ◽  
Resonance Phenomena ◽  
Resonant Phenomena

Currently, adjustable medium voltage electric drives are mostly based on frequency converters with active rectifiers. In cases where the medium voltage network has extended cable lines, adverse resonance phenomena can occur in the network, due to which, when significant harmonics of the FC with AR are applied to the resonance region, critical voltage distortions occur in the distribution network. The solution to this problem can be the installation of special filters that correct the frequency response of the network. However, this requires experimental determination of the frequency response for all possible modes of power supply, which is a difficult technical task in practice. Therefore, it is relevant to study an adaptive method of reducing voltage distortions caused by the operation of a FC in networks with resonant phenomena.When developing a method for diagnosing resonance phenomena and an improved PWM algorithm, the existing PWM algorithms used by manufacturers of electric drives with AR has been analyzed and the well-known methods of mathematical modeling of frequency converters and power supply systems has been used. The main assumption of the model is representation of the inverter as a current source. Anadaptive method for reducing distortion in networks with resonant phenomena based on improved PWM algorithm that allows excluding from the harmonic series of the voltage curve of the frequency converter the group of harmonics included in the resonance region has been developed.A comparative analysis of the FC with non-adaptive and adaptive PWM has been performed using simulation model of the FC system with AR – medium voltage network. It has been found that the use of the adaptive PWM algorithm significantly reduces the distortion in the network in the presence of resonance phenomena.Method proposed can be applied to detect in-plant networks resonance in different frequency ranges when power supply mode is changing. Adaptive algorithm can be applied in the design of FC with AR.

scholarly journals A conceptual framework for improving effectiveness of risk management in supply networks

2020 ◽  
Vol 31 (1) ◽  
pp. 77-98 ◽  
Author(s):  
Atanu Chaudhuri ◽  
Abhijeet Ghadge ◽  
Barbara Gaudenzi ◽  
Samir Dani
Keyword(s):  
Risk Management ◽  
Supply Chain ◽  
Conceptual Framework ◽  
Negative Impact ◽  
Supply Network ◽  
Supply Networks ◽  
Content Type ◽  
Network Characteristics ◽  
Management Capabilities ◽  
Risk Planning

PurposeThe purpose of the paper is to develop a conceptual framework for improving the effectiveness of risk management in supply networks following a critical literature review.Design/methodology/approachA critical review of 91 scholarly journal articles published between 2000 and 2018 supports the development of an integrated conceptual framework.FindingsThe findings emphasize that supply chain integration (SCI) can have both a positive and negative impact on the effectiveness of risk management in supply networks. It is possible to have a positive effect when SCI can be used to develop competencies in joint risk planning within the organization and with wider supply network members and, in turn, to develop collaborative risk management capabilities. Supply network characteristics can influence whether and the extent to which SCI has a positive or negative impact on risk management effectiveness.Research implicationsThe conceptual framework can be used to empirically assess the role of SCI for effective risk management. Dynamic evaluation of the effectiveness of risk management and potential redesign of the supply network by considering other contingent factors are some future research avenues.Practical implicationsThere is a need for developing specific competencies in risk planning within organizations and joint risk planning with supply network members which, in turn, can help develop collaborative risk management capabilities to improve the effectiveness of risk management in supply networks. Network characteristics will influence whether and the extent to which SCI results in the effectiveness of risk management.Originality valueMoving beyond recent (systematic) reviews on supply chain risk management, this study develops a novel conceptual framework interlinking SCI and the effectiveness of risk management while considering network characteristics.

Mitochondrial hyperfusion: a friend or a foe

2020 ◽  
Vol 48 (2) ◽  
pp. 631-644 ◽  
Author(s):  
Rajdeep Das ◽  
Oishee Chakrabarti
Keyword(s):  
Negative Impact ◽  
Cellular Stress ◽  
Cellular Homeostasis ◽  
Mitochondrial Population

The cellular mitochondrial population undergoes repeated cycles of fission and fusion to maintain its integrity, as well as overall cellular homeostasis. While equilibrium usually exists between the fission–fusion dynamics, their rates are influenced by organellar and cellular metabolic and pathogenic conditions. Under conditions of cellular stress, there is a disruption of this fission and fusion balance and mitochondria undergo either increased fusion, forming a hyperfused meshwork or excessive fission to counteract stress and remove damaged mitochondria via mitophagy. While some previous reports suggest that hyperfusion is initiated to ameliorate cellular stress, recent studies show its negative impact on cellular health in disease conditions. The exact mechanism of mitochondrial hyperfusion and its role in maintaining cellular health and homeostasis, however, remain unclear. In this review, we aim to highlight the different aspects of mitochondrial hyperfusion in either promoting or mitigating stress and also its role in immunity and diseases.

Health Communication: Implications for Diverse Populations

2011 ◽  
Vol 18 (1) ◽  
pp. 12-19
Author(s):  
Amy Hasselkus
Keyword(s):  
Health Care ◽  
Health Communication ◽  
Negative Impact ◽  
Linguistically Diverse ◽  
Good Health ◽  
The United States ◽  
Poor Health ◽  
Health Care Decisions ◽  
Diverse Backgrounds ◽  
Health Related

The need for improved communication about health-related topics is evident in statistics about the health literacy of adults living in the United States. The negative impact of poor health communication is huge, resulting in poor health outcomes, health disparities, and high health care costs. The importance of good health communication is relevant to all patient populations, including those from culturally and linguistically diverse backgrounds. Efforts are underway at all levels, from individual professionals to the federal government, to improve the information patients receive so that they can make appropriate health care decisions. This article describes these efforts and discusses how speech-language pathologists and audiologists may be impacted.

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