scholarly journals Power Quality in AC Islanded Microgrids: Technical Framework and State of the Art Review

2020 ◽  
Vol 40 (3) ◽  
pp. 29-37
Author(s):  
Vanessa Quintero-Molina ◽  
Ana María Blanco ◽  
Miguel Romero-L ◽  
Jan Meyer ◽  
Andrés Pavas
Keyword(s):  
Power Quality ◽  
Distribution Systems ◽  
Negative Impact ◽  
Control Strategies ◽  
Future Research ◽  
Local Networks ◽  
Islanded Mode ◽  
Power Quality Disturbances ◽  
And Control ◽  
The Impact

In recent years, operation and control strategies in distribution systems have changed due to the increase in the connection of distributed generation sources (DGs). Small local networks with electricity users and DGs are known as microgrids. These microgrids can operate independently (islanded) or in collaboration (interconnected) with the main network or other microgrids. Some advantages of interconnected microgrids include the reduction of losses, an increase in reliability, and decentralized operation under fault conditions. Nevertheless, when a microgrid operates in islanded mode, its electrical characteristics change and, consequently, the severity of power quality disturbances can increase, as well as their negative impact on electronic devices (loads and DG devices). This paper presents a comprehensive literature review of existing studies on power quality disturbances in islanded microgrids and identifies the most relevant needs for future research on this topic. Detailed information is analyzed to compare the differences between disturbance levels in both interconnected and islanded microgrids. In the case of harmonic disturbances, the impact of the different microgrid configurations is also analyzed.

scholarly journals A Review of Fouling Mechanisms, Control Strategies and Real-Time Fouling Monitoring Techniques in Forward Osmosis

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 695 ◽  
Author(s):  
Ibrar Ibrar ◽  
Osamah Naji ◽  
Adel Sharif ◽  
Ali Malekizadeh ◽  
Alaa Alhawari ◽  
...  
Keyword(s):  
Real Time ◽  
Membrane Fouling ◽  
Control Strategies ◽  
Forward Osmosis ◽  
Future Research ◽  
Negative Consequences ◽  
Critical Flux ◽  
Monitoring Technologies ◽  
And Control ◽  
The Impact

Forward osmosis has gained tremendous attention in the field of desalination and wastewater treatment. However, membrane fouling is an inevitable issue. Membrane fouling leads to flux decline, can cause operational problems and can result in negative consequences that can damage the membrane. Hereby, we attempt to review the different types of fouling in forward osmosis, cleaning and control strategies for fouling mitigation, and the impact of membrane hydrophilicity, charge and morphology on fouling. The fundamentals of biofouling, organic, colloidal and inorganic fouling are discussed with a focus on recent studies. We also review some of the in-situ real-time online fouling monitoring technologies for real-time fouling monitoring that can be applicable to future research on forward osmosis fouling studies. A brief discussion on critical flux and the coupled effects of fouling and concentration polarization is also provided.

scholarly journals Phony peach disease: past and present impact on the peach industry in the southeastern U.S.A

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Kendall A. Johnson ◽  
Clive H. Bock ◽  
Phillip M. Brannen
Keyword(s):  
New Technologies ◽  
Current Knowledge ◽  
Future Research ◽  
Management Options ◽  
Disease Epidemiology ◽  
Pathogen Diversity ◽  
Foundational Research ◽  
Global Threat ◽  
And Control ◽  
The Impact

Abstract Background Phony peach disease (PPD) is caused by the plant pathogenic bacterium Xylella fastidiosa subsp. multiplex (Xfm). Historically, the disease has caused severe yield loss in Georgia and elsewhere in the southeastern United States, with millions of PPD trees being removed from peach orchards over the last century. The disease remains a production constraint, and management options are few. Limited research has been conducted on PPD since the 1980s, but the advent of new technologies offers the opportunity for new, foundational research to form a basis for informed management of PPD in the U.S. Furthermore, considering the global threat of Xylella to many plant species, preventing import of Xfm to other regions, particularly where peach is grown, should be considered an important phytosanitary endeavor. Main topics We review PPD, its history and impact on peach production, and the eradication efforts that were conducted for 42 years. Additionally, we review the current knowledge of the pathogen, Xfm, and how that knowledge relates to our understanding of the peach—Xylella pathosystem, including the epidemiology of the disease and consideration of the vectors. Methods used to detect the pathogen in peach are discussed, and ramifications of detection in relation to management and control of PPD are considered. Control options for PPD are limited. Our current knowledge of the pathogen diversity and disease epidemiology are described, and based on this, some potential areas for future research are also considered. Conclusion There is a lack of recent foundational research on PPD and the associated strain of Xfm. More research is needed to reduce the impact of this pathogen on peach production in the southeastern U.S., and, should it spread internationally, wherever peaches are grown.

scholarly journals Optimal Harmonic Mitigation in Distribution Systems with Inverter Based Distributed Generation

2021 ◽  
Vol 11 (2) ◽  
pp. 774 ◽  
Author(s):  
Ahmed S. Abbas ◽  
Ragab A. El-Sehiemy ◽  
Adel Abou El-Ela ◽  
Eman Salah Ali ◽  
Karar Mahmoud ◽  
...  
Keyword(s):  
Power Quality ◽  
Distributed Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Renewable Energy Sources ◽  
Harmonic Distortion ◽  
Planning Problem ◽  
Voltage Profile ◽  
Harmonic Mitigation ◽  
The Impact

In recent years, with the widespread use of non-linear loads power electronic devices associated with the penetration of various renewable energy sources, the distribution system is highly affected by harmonic distortion caused by these sources. Moreover, the inverter-based distributed generation units (DGs) (e.g., photovoltaic (PV) and wind turbine) that are integrated into the distribution systems, are considered as significant harmonic sources of severe harmful effects on the system power quality. To solve these issues, this paper proposes a harmonic mitigation method for improving the power quality problems in distribution systems. Specifically, the proposed optimal planning of the single tuned harmonic filters (STFs) in the presence of inverter-based DGs is developed by the recent Water Cycle Algorithm (WCA). The objectives of this planning problem aim to minimize the total harmonic distortion (THD), power loss, filter investment cost, and improvement of voltage profile considering different constraints to meet the IEEE 519 standard. Further, the impact of the inverter-based DGs on the system harmonics is studied. Two cases are considered to find the effect of the DGs harmonic spectrum on the system distortion and filter planning. The proposed method is tested on the IEEE 69-bus distribution system. The effectiveness of the proposed planning model is demonstrated where significant reductions in the harmonic distortion are accomplished.

Public reassurance following a collective trauma event: a scoping review of the evidence to inform police practice

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lyndal Hickey ◽  
Louise Hams ◽  
Lauren Kosta
Keyword(s):  
Scoping Review ◽  
Negative Impact ◽  
Traumatic Events ◽  
Future Research ◽  
Collective Trauma ◽  
Content Type ◽  
Community Attitudes ◽  
The Public ◽  
Police Agencies ◽  
The Impact

PurposeThis paper examines the empirical research on police reassurance following a collective trauma event (CTE).Design/methodology/approachUsing a scoping review methodology, this paper sought to establish the extent, range and nature of published literature on policing responses to collective traumatic events, and to identify key features of this form of direct practice. Included papers needed to focus on police responses oeassurance with the public related to events (pre-or post) that could be regarded as collective trauma events by nature or scale. Searches were conducted using the Web of Science, SCOPUS and PsychINFO databases for literature published between January 2000 and December 2019.FindingsFourteen articles met the inclusion criteria. The key themes identified: (1) measuring the impact of reassurance and community policing; (2) community attitudes to policing and social disorder/critical events; (3) police workforce responses to traumatic events; and (4) interventions to support police to respond to their community.Research limitations/implicationsFuture research needs to examine the elements that create a robust organisational infrastructure that can withstand the demands of policing in ordinary and extraordinary times. Fundamental to the studies in this review is the relationship between the police agencies and the community. The nature of this relationship and how it can be strengthened to ameliorate the negative impact of CTEs in communities needs further exploration.Originality/valueThis paper provides important findings that can inform future reassurance policing practice and research.

The Effect of Concealed Handgun Carry Deregulation in Arizona on Crime in Tucson

2018 ◽  
Vol 30 (8) ◽  
pp. 1186-1203 ◽  
Author(s):  
Michael R. Smith ◽  
Matthew Petrocelli
Keyword(s):  
El Paso ◽  
Future Research ◽  
Multiple Time ◽  
Multiple Time Series ◽  
Training Requirements ◽  
State Adoption ◽  
Concealed Carry ◽  
And Control ◽  
The Impact ◽  
And Training

In 2010, the Arizona legislature effectively deregulated concealed handgun carry in the state by passing Senate Bill (SB) 1108, which eliminated licensing and training requirements for concealed carry. Although researchers have extensively examined the impact of state adoption of concealed carry laws, almost nothing is known about the effects of deregulating concealed carry altogether. This study contributes to the more guns, less crime debate by examining the impact of Arizona’s decision to deregulate concealed carry. Using a multiple time-series research design with an experimental (Tucson) and control city (El Paso), the present study examines the impact of deregulation on handgun-related violent crime and gun larcenies in Arizona’s second largest city—Tucson. We find that the passage of SB 1108 had no impact on handgun-related offenses that could be expected to change following deregulation. The implications of these findings for policy making and future research are discussed.

scholarly journals The Effect of Participation Effort on CSR Participation Intention: The Moderating Role of Construal Level on Consumer Perception of Warm Glow and Perceived Costs

2019 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Yunjeong Ahn ◽  
Jieun Lee
Keyword(s):  
Negative Impact ◽  
Positive Impact ◽  
Consumer Participation ◽  
Amazon Mechanical Turk ◽  
Future Research ◽  
Construal Level ◽  
Warm Glow ◽  
Contrast Analysis ◽  
Construal Levels ◽  
The Impact

Consumer participation typically reduces consumer skepticism and leads to a positive response to corporate social responsibility (CSR) activities. Although many companies are encouraging consumers to participate in CSR activities, there is still insufficient research on the effectiveness of this strategy. That is, prior studies do not provide guidelines on the effectiveness of requiring consumers to participate in CSR activities. We examine the impact of the required participation effort on CSR participation intention, focusing on the differences in consumers’ perception of a warm glow feeling and costs according to their construal level. For this study, 107 participants were recruited using Amazon Mechanical Turk. We tested hypotheses using a 2 (CSR participation effort) × 2 (construal level) between-subject analysis of variance (ANOVA), planned contrast analysis, and mediation analysis. The results indicate that for consumers with high construal levels who perceive participation efforts as warm glow, participation efforts have a positive impact on CSR participation intention. However, for those with low construal levels who perceive participation efforts as costs, high required efforts have a negative impact on their participation intention. Finally, we discuss the implications of these results, discuss the limitations, and suggest future research directions.

Assessing the Impact of Temperature Change on the Effectiveness of Insecticide-Treated Nets

2011 ◽  
Vol 3 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Gregory J. Davis
Keyword(s):  
Control Strategies ◽  
Global Climate ◽  
Financial Burden ◽  
Insecticide Treated Nets ◽  
Policy Makers ◽  
Agent Based ◽  
Mosquito Abundance ◽  
Vector Borne ◽  
And Control ◽  
The Impact

Malaria is a vector-borne illness affecting millions of lives annually and imposes a heavy financial burden felt worldwide. Moreover, there is growing concern that global climate change, in particular, rising temperature, will increase this burden. As such, policy makers are in need of tools capable of informing them about the potential strengths and weaknesses of intervention and control strategies. A previously developed agent-based model of the Anopheles gambiae mosquito is extended, one of the primary vectors of malaria, to investigate how changes in temperature influence the dynamics of malaria transmission and the effectiveness of a common malaria intervention: insecticide-treated nets (ITNs). Results from the simulations suggest two important findings. Consistent with previous studies, an increase in mosquito abundance as temperature increases is observed. However, the increase in mosquito abundance reduces the effectiveness of ITNs at a given coverage level. The implications and limitations of these findings are discussed.

scholarly journals The Impact of the Organizational Culture on Hotel Outsourcing and Sustainable Performance an Empirical Application in the Egyptian Hotel Sector

2020 ◽  
Vol 12 (22) ◽  
pp. 9687
Author(s):  
Mahmoud Gebril Taha ◽  
Tomás F. Espino-Rodríguez
Keyword(s):  
Organizational Culture ◽  
Organizational Performance ◽  
Structural Model ◽  
Negative Impact ◽  
Negative Relationship ◽  
Positive Influence ◽  
Future Research ◽  
Competing Values ◽  
Sustainable Performance ◽  
The Impact

In recent years, the concept of an organizational culture in hotels has held an important position on both a theoretical and practical level because this culture significantly affects organizational performance and the strategies adopted by hotels. Therefore, it is considered one of the key factors in determining hotels’ tendency towards outsourcing and sustainable performance. In this study, we aim to analyze the impact of the organizational culture on the level of outsourcing and sustainable performance. To do so, we will use the Competing Values Framework (CVF), which divides organizational culture into four typologies: hierarchical, group, rational, and development cultures. A personal questionnaire was administered to the directors or managers of 114 hotels located in two Egyptian cities: Hurgada and Sharm El Sheikh. The results of the structural model suggest the negative impact of the hierarchical and development cultures on the level of outsourcing. The results show a positive influence of the four types of organizational culture on sustainable performance, suggesting that these hotels have a strong interest in sustainability and the environment. The findings reveal a negative relationship between the level of outsourcing and sustainable performance. Finally, this study presents academic and practical implications, as well as recommendations for future research.

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