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This paper presents findings from an online questionnaire that collected experiences from the Facebook outage on October 4th, 2021, an event that affected approximately three billion users around the globe. The purpose of the study is to contribute to recent discussions digital disconnection and digital wellbeing by using an extraordinary event of involuntary disconnection as point of departure. Our research questions were: Where were people when the services shut down, what did they think and what did they do? What correlations can be found between usage/attitudes to social media and the experiences of the outage? How can the outage of October 4th be understood as a snapshot of our cultural condition? The questionnaire was distributed to 463 Swedish university students and 191 responses were received. Our analysis shows how the involuntary disconnection caused by the outage was an event that highlights the ambivalence of digital life. It also points to some correlations between general social media use and attitudes, and the experiences and activities during the outage. The paper ends with a discussion on the implications that these findings may have for further research into digital disconnection. [ABSTRACT FROM AUTHOR]

Copyright of Revista Electrónica de Psicología Iztacala is the property of Facultad de Estudios Superiores Iztacala and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Intro: Communication is understood to be a pillar of democracy. Therefore, governments around the world enact laws which make it easier for politicians to communicate with their constituents. However, some governments also restrict this ability during campaign seasons as a way of unclogging the media. In the United States, congressional election blackout dates are periods in which politicians are not allowed to engage in mass unsolicited mailing of political advertising. Because the prohibition only applies to unsolicited media, we theorize that we should see the transition from one type of communication to another. Methods: To test this effect, we created a database containing all tweets by all Members of Congress from the last three Congresses. Results: We find that immediately during the blackout periods, members of Congress substantially increase the number of tweets they post. Discussion: We conclude that Members of Congress are strategic in their ability to exchange communication outlets. [ABSTRACT FROM AUTHOR]

Analysis of various accident scenarios is vital for the safety assessment of nuclear fuel storage facilities. The accidents in the storage vault due to loss of cooling are generally considered highly uncertain since the accident progression is slow (in comparison to reactors) and allows time for remedial activities to the operator. In the present work, numerical simulations of different accident scenarios have been carried out for a short duration to understand the situation better. Thermal aspects of accident conditions such as failure of the suction blower, drying of cooling water at the chiller, and combined effect of both accidents were investigated. The airflow inside the ventilated enclosures due to the failure of the blower and the rise in inlet air temperature is analyzed numerically. The temperature distributions inside the vault and the rise in temperature of the sub-assemblies and magazines have been studied. The key mechanisms of heat transfer, which take part in nuclear fuel storage vault for post-accident conditions, were identified. The study will be helpful to classify various accident conditions based on their thermal implications and the model developed can be used to design passive cooling systems. [ABSTRACT FROM AUTHOR]

Piped drinking water supplies are exposed to a range of threats. Changing hazard situations arise from climate change, digitisation, and changing conditions in the power supply, among other things. Risk and crisis management adapted to the hazard situation can increase the resilience of the piped drinking water supply. Analogous to the risk management system, this article describes a methodology that ranges from hazard analysis with the prioritisation of 57 individual hazards to vulnerability assessment with the help of balance sheet structure models (BSM) and the planning and implementation of measures to increase the resilience of the piped drinking water supply in a targeted manner. The work steps mentioned build on each other and were tested using the case study of a water supply company in Saxony (Germany). As a result, priority hazards are identified, the remaining supply periods and replacement and emergency water requirements are determined as part of the vulnerability assessment, and finally, planning principles for increasing resilience are documented. The methodology focuses primarily on practicable application by water supply companies. [ABSTRACT FROM AUTHOR]

Fluctuations in electricity demand can lead to inefficiencies in diesel generators (DEG) and potentially trigger blackouts, as experienced by PT Indolakto. This study aims to identify the performance parameters of a 2 MW DEG and formulate strategies to prevent blackouts caused by the 2 MW DEG at PT Indolakto. The research used data collection techniques including field observations, interviews, literature studies, and performance test analysis. The results showed that the efficiency of the 2 MW DEG at load reached 44%, indicating there is still reserve power. An overload of 21% from the generator's capacity resulted in a blackout and a system frequency drop of 13.4 Hz from the normal frequency. Although the 2 MW DEG has adequate efficiency, optimization is necessary to prevent blackouts. One strategy is to use the 2 MW DEG as a system reserve for critical loads. [ABSTRACT FROM AUTHOR]

During the Russian-Ukrainian war, mass power outages occurred in Ukraine, caused by Russian attacks on civilian infrastructure, namely on the generating and distribution capacities of the power system. The risks associated with such outages cover not only the issue of uninterrupted operation of the economy directly, but also more complex aspects related to cyber security. The impact of such outages on the cyber security of information and communication systems is considered, namely, the second-order effects, such as interruptions with information observability, violation of the integrity of the protection infrastructure, overloading of monitoring teams and response to false alarms. All these factors alter the threat landscape for the system and must be considered in security policy and during the threat modeling process accordingly. An analysis of hidden cyber security risks arising in connection with massive power outages was conducted. Possible approaches to taking such risk factors into account when modeling threats, as well as methods of countermeasures, are given. [ABSTRACT FROM AUTHOR]

A grid blackout is an intractable problem with serious economic consequences in many developing countries. Although it has been proven that microgrids (MGs) are capable of solving this problem, the uncertainties regarding when and for how long blackouts occur lead to extreme difficulties in the design and operation of the related MGs. This paper addresses the optimal design problem of the MGs considering the uncertainties of the blackout starting time and duration utilizing the kernel density estimator method. Additionally, uncertainties in solar irradiance and ambient temperature are also considered. For that, chance-constrained optimization is employed to design residential and industrial PV-based MGs. The proposed approach aims to minimize the expected value of the levelized cost of energy ( L C O E ), where the restriction of the annual total loss of power supply ( T L P S ) is addressed as a chance constraint. The results show that blackout uncertainties have a considerable effect on calculating the size of the MG's components, especially the battery bank size. Additionally, it is proven that considering the uncertainties of the input parameters leads to an accurate estimation for the LCOE and increases the MG reliability level. [ABSTRACT FROM AUTHOR]

Copyright of Engineer Military Bulletin / Muszaki Katonai Közlöny is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The decision-making of generator start-up sequence plays a pivotal role in the power system restoration process following the blackout. In this paper, an optimized deep Q-learning network (DQN) algorithm is proposed to address this challenge. The generator start-up process is modeled as a Markov Decision Process (MDP) based on its characteristics. The DQN is tasked with deciding both the generator start-up sequence and the corresponding restoration path. To address the limitations of DQN, such as low exploration efficiency and slow convergence, the study incorporates the Artificial Potential Field (APF) algorithm to refine the reward function of it. This integration results in the development of the F-DQN (APF-DQN) algorithm, which enhances training efficiency. The effectiveness of this proposed method is demonstrated through the IEEE 39-bus test system. The results reveal that the DQN algorithm is capable of efficiently solving the model of the generator start-up sequence after the blackout. Moreover, the F-DQN algorithm exhibits superior learning efficiency, faster convergence, and higher-quality optimal solutions compared to the DQN. This paper also discusses the applicability of this method under partial blackouts. When compared to other decision-making algorithms, the proposed method offers a restoration scheme that is both time-efficient and results in increased electricity generation. [ABSTRACT FROM AUTHOR]

Due to the significant gap between demand and supply of electricity, power utility companies employ rolling blackouts, in which the power supply to different regions is cut-off periodically for a specified duration. However, this causes increased user inconvenience as consumers are left without power; also, a large undesirable blackout may occur if the circuit breakers are not opened in time. To solve this problem, this paper has developed a more pragmatic approach in which a power threshold limit is imposed on households during times of deficit power supply. This paper presents five algorithms designed to allocate load thresholds to households in a fair manner. Some of these algorithms perform the worst (high violations) in some time slots and best (minimal violations) in other slots, but none guarantees minimal mean violation across all the time slots. In this regard, this paper has also developed a novel optimal algorithm that ensures a minimal violation percentage of the allotted thresholds across all time slots in all the households of a neighbourhood. It also employs multiple heuristics for threshold allocation, thereby preventing household starvation. The algorithms are evaluated on a real-world dataset. Its mean violation across all the houses goes as low as nearly 45% and is minimum across all the time slots. It performs all the algorithms used for power limit distribution. This result demonstrates the effectiveness of the developed technique in the implementation of the brownout scheme in practise. [ABSTRACT FROM AUTHOR]

Today humanity is going through a period of great upheavals and rapid changes in every sphere of life, including the environment, that inevitably lead to general destabilisation and disruptions. In the latest novel by Rumaan Alam, apocalyptic Leave the World Behind (2020), a crisis appears to reshape our closest bonds and forge new ones. This story of an invisible terror deals with cataclysmic but mysterious events that shut down the communication networks we over-rely on, and sees an almost overwhelming sense of uncertainty, panic and increasing anxiety. Isolated in the remote holiday house with the Vermont stone kitchen tops and night-lit swimming pool, a couple of New Yorkers and their teenage children are looking forward to taking a rest from the routines of city life when catastrophe strikes. In addition to the major theme of the threat of human extinction, Leave the World Behind explores the relationship between class and race and the complexities of parenthood and solitude during an unspecified disaster. Those issues are included in the context of the global problem of anthropogenic impacts on the environment. At the same time, Alam demonstrates how habituation to the ongoing crises in the modern world, including social-ecological transformations, affects the understanding of a severe situation people are facing and ways to prevent it: they have increasing tolerance for the absurd. The suspenseful, provocative and prescient book, Leave the World Behind, captures the generalised panic of 2020, the year of a global outbreak of coronavirus. As a kind of end-of-the-world fiction, the novel is full of moments of exquisite recognition and reappraising of our attitudes the article discusses. [ABSTRACT FROM AUTHOR]

The complexities in modern power systems are increasing daily with the integration of renewable sources and an increasing number of power system components such as lines, buses, transformers, FACTs devices, and many more. The complexity and the limitations in power transfer capabilities for meeting the power consumptions under the contingency condition may occur in the system. The power system contingencies may lead to blackouts and complete system failure. Therefore, power system contingency analysis is a very emerging topic in power system analysis. This paper identifies some previous contingency analysis research and finds the different research persons and journal sources that publish related articles in this field through a bibliometric analysis. [ABSTRACT FROM AUTHOR]

Purpose: To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model. Material and methods: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively). Results: Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances. Conclusion: Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist’s choice of instruments and settings. [ABSTRACT FROM AUTHOR]

Purpose: Hyperventilation is considered a major risk factor for hypoxic blackout during breath-hold diving, as it delays the apnea breaking point. However, little is known about how it affects oxygenation, the diving response, and spleen contraction during serial breath-holding. Methods: 18 volunteers with little or no experience in freediving performed two series of 5 apneas with cold facial immersion to maximal duration at 2-min intervals. In one series, apnea was preceded by normal breathing and in the other by 15 s of hyperventilation. End-tidal oxygen and end-tidal carbon dioxide were measured before and after every apnea, and peripheral oxygen saturation, heart rate, breathing movements, and skin blood flow were measured continuously. Spleen dimensions were measured every 15 s. Results: Apnea duration was longer after hyperventilation (133 vs 111 s). Hyperventilation reduced pre-apnea end-tidal CO2 (17.4 vs 29.0 mmHg) and post-apnea end-tidal CO2 (38.5 vs 40.3 mmHg), and delayed onset of involuntary breathing movements (112 vs 89 s). End-tidal O2 after apnea was lower in the hyperventilation trial (83.4 vs 89.4 mmHg) and so was the peripheral oxygen saturation nadir after apnea (90.6 vs 93.6%). During hyperventilation, the nadir peripheral oxygen saturation was lower in the last apnea than in the first (94.0% vs 86.7%). There were no differences in diving response or spleen volume reduction between conditions or across series. Conclusions: Serial apneas revealed a previously undescribed aspect of hyperventilation; a progressively increased desaturation across the series, not observed after normal breathing and could heighten the risk of a blackout. [ABSTRACT FROM AUTHOR]

The massive blackout that occurred in August 2003 left over 50 million people in the northeastern and midwestern parts of the United States without electricity and caused billions of dollars in economic losses. This event highlighted the importance of sustainable and resilient energy infrastructure. Our study examines the impact of this blackout on the sustainability of financial markets by analyzing the liquidity and information asymmetry of U.S. stocks listed on major exchanges. Our results show that the blackout had a negative impact on the financial market's liquidity, as evidenced by a significant widening of bid–ask spreads and a decrease in the market quality index. We also find an increase in information asymmetry during the blackout period, as measured by higher realized spreads. Furthermore, our study reveals that the blackout had a border impact on global financial markets and the negative effect on liquidity persisted even after two weeks. [ABSTRACT FROM AUTHOR]

Aim: The article aimed to present the essence of the systemic approach to business continuity management (BCMS - Business Continuity Management System) and to determine the level of maturity of business continuity systems implemented in small and medium-sized enterprises about selected groups of external threats, corresponding to current economic, political and legal conditions. Project/methodology/approach: The subject of this study is an analysis based on the available resources in the literature and the results of the conducted empirical study. Findings: As a result of the literature study, it has been proven that organizations are exposed to many threats that affect business continuity to varying degrees. The fundamental element of organizational prevention at the operational level is the business continuity plan, which defines response mechanisms in the event of an incident or crisis that negatively affects the stability of implemented projects. The analysis of the research results indicated that the primary response mechanism established in modern organizations transfers the burden of the effects of the crisis to employees, as it is related to the performance of professional duties using remote communication methods and techniques. Research limitations/implications: The primary research limitation was the difficulty in obtaining a representative research sample, which is why it was decided to limit the scope of the research and carry it out in enterprises belonging to high-tech industries. Bearing in mind that the scope of the study referred to conditions which, due to the increased uncertainty of the general (intermediate) environment, are subject to changes and improvement of modern management systems, it is recommended to conduct the research again in other economic sectors. Expanding the study's scope will allow the development of a catalogue of good practices, including a more comprehensive catalogue of threats to the continuity of modern business organizations. Originality/value: The article presents previously untested mechanisms ensuring business continuity about current threats – blackout and energy lockdown. The analyses contained therein may be the basis for improving internal crisis response systems, especially in small and medium-sized enterprises. [ABSTRACT FROM AUTHOR]

The necessary precautions should be taken in order to prevent service interruption during the maintenance and repairing of electricity networks. Among these measures, emergencies that may occur in the network should be foreseen, hazard scenarios should be created, and solutions should be developed. If these are not done, a blackout, which first follows the local regions and eventually results in the collapse of the national electrical network, may take place. In this study, the national blackout of Turkey that occurred on 31 March 2015 is examined. The information about Turkey's electrical infrastructure and its energy policies was provided, as well as the reliability assessment criteria for power systems and examples of significant blackouts that occurred worldwide. The direct relation between line voltage and system frequency was provided with mathematical derivation by using real data taken from a local industrial zone. Then, a case study is presented to demonstrate this direct relation. The causes, development process, and consequences of the blackout are discussed in detail, and some recommendations are offered to increase the security of the electrical infrastructure and to prevent future occurrences while ensuring the sustainability of the system. [ABSTRACT FROM AUTHOR]

Recent history demonstrates that threat has no borders, though risk does, due to national and regional differences in vulnerabilities and exposure landscapes. The difference between well and poorly managed threat is striking. Inequalities in preparing for threats as a function of their type are still apparent. Compared to more concerning electromagnetic interference threats, the impact of geomagnetic disturbance (GMD) on power grid operation is not well studied. The need for detailed research of GMD negative impacts is expected to broaden awareness. The amplitude of geomagnetically induced currents (GICs) is treated as a uniform measure of danger that can be processed by various stakeholders. Hence, methods for increasing the accuracy of GIC representation are presented in this paper. A low-entropy signal is defined and it is shown that the feature of low signal entropy can be used for increasing the accuracy of the measurement equipment. At the end, a full-system view of GMD impact on power grid operation is given. [ABSTRACT FROM AUTHOR]

During the Russian-Ukrainian war, mass power outages occurred in Ukraine, caused by Russian attacks on civilian infrastructure, namely on the generating and distribution capacities of the power system. The risks associated with such outages cover not only the issue of uninterrupted operation of the economy directly, but also more complex aspects related to cyber security. The impact of such outages on the cyber security of information and communication systems is considered, namely, the second-order effects, such as interruptions with information observability, violation of the integrity of the protection infrastructure, overloading of monitoring teams and response to false alarms. All these factors alter the threat landscape for the system and must be considered in security policy and during the threat modeling process accordingly. An analysis of hidden cyber security risks arising in connection with massive power outages was conducted. Possible approaches to taking such risk factors into account when modeling threats, as well as methods of countermeasures, are given. [ABSTRACT FROM AUTHOR]

Unreliable electricity supply is a widespread problem in developing countries. This paper examines the impact of power outages on firm productivity in East Africa, considering the effect of generator ownership in general and during blackouts. The results show large negative effects of power outages on productivity and a mitigating effect of self-generating during power outages of approximately the same size. However, self-generation is also found to generally reduce productivity due to the idle capital effect of unused generators during blackout-free times. This finding highlights that self-generation is only profitable for firms if the experienced power outages are severe enough. [ABSTRACT FROM AUTHOR]

This paper proposes an imputation method using a bidirectional k-nearest components search based local linear regression method. The bidirectional k-nearest-components search method selects components in the dynamic range from the missing points. Unlike the existing methods, which use a fixed-size window, the proposed method can flexibly select adjacent components in an imputation problem. The weight values assigned to the components around the missing points are calculated using local linear regression. The local linear regression method is free from the rank problem in a matrix of dependent variables. In addition, it can calculate the weight values that reflect the data flow in a specific environment, such as a blackout. The original missing values were estimated from a linear combination of the components and their weights. Finally, the estimated value imputes the missing values. In the experimental results, the proposed method outperformed the existing methods when the error between the original data and imputation data was measured using MAE and RMSE. [ABSTRACT FROM AUTHOR]

The results of simulation of a geomagnetically induced current impact on the consolidated power system of the center of Russia expected during a strong magnetic storm are represented. It is shown that a complex of factors appears during this impact that can induce the progression of a blackout: a significant decrease in voltage on a set of electrical power elements, the mass cutoff of power transmission lines under the effect of relay protection, and the dangerous heating of construction elements of power transformers. [ABSTRACT FROM AUTHOR]

The need for renewable energy is growing as a result of climate change, global warming and the subsequent increase in natural disasters brought on by the use of carbon-emitting resources. An earlier examination of potential future energy pathways demonstrates that it is theoretically feasible to simultaneously improve energy security, air quality, and access while preventing disastrous climate change. Land, energy, and water are some of our most precious resources, but how and how much we use them also affects the climate. At the national level, renewable energy prospects would be very diverse. The rise in global economic activities results in higher demand in electricity, as its one of the main sources of energy. This leads to search for renewable energy sources. Solar cells are one of the technological innovations that directly convert light energy into electricity through the photovoltaic effect, creating electrical charges that are free to travel through semiconductors. But due to uncertainty in the weather and the influence of weather on power generation makes the integration of PV cell into existing grid a difficult part. To operate the electricity distribution system efficiently one should know both the demand and supply of distribution center. To solve this issue, a statistical model that forecasts the power generation at the PV cell plant and aids in grid operation, as well as information about the impact of weather on power generation, is required. In addition to using traditional time series models fundamental machine learning methods like Linear Regression, Random Forest Model, XG Boost, and Support Vector Regression (SVR) models are also trained and applied for prediction. [ABSTRACT FROM AUTHOR]

The danger of a total blackout in a wide area or, even worse, in a country is always present. The restoration methods after a blackout mainly focus on the strategy that the dispatchers in the control centers of the Transmission System Operator will follow than the abilities that the distribution's microgrids have. This study suggests a restoration technique to improve distribution system resilience following a blackout, using distributed generation for the restoration of important loads. The goal of the restoration problem is to maximize the number of critical loads that are restored following the catastrophic incident. Under the restrictions of the DGs and the network, the DGs with good black start capability are restored first. Load weight and node importance degree are suggested during the recovery path selection procedure, while taking node topological importance and load importance into account. A mixed-integer linear program (MILP) is used to simulate the issue, and the modified IEEE 39-bus test system is used to verify the efficacy of the suggested restoration approach. [ABSTRACT FROM AUTHOR]

Many citizens of European countries may soon experience a long and extensive blackout. The lack of predictability in the output of renewable energy sources, aggravating the problem of consistently matching supply with demand on electric grids, along with cyber-attacks or even worse unpredictable incidents in the electric grid are some factors that may mean a blackout is much more likely than in previous years. This paper covers the possibility of an extensive blackout in a country of the interconnected European electricity transmission system or, even worse, a blackout in a wide area of the European continent. The topic of this paper becomes even more important and timely given the energy crisis due to the war in Ukraine, which has made the possibility of a blackout in the winter of 2022–2023 high. First, the major European blackouts that occurred in the past 20 years are presented, examining their causes. On 8 January 2021, the European electricity grid was divided into two separate sections, with different frequencies; some additional scenarios are considered which, if they had happened, could have led to blackouts in some European countries or, even worse, a wide area of Europe. This work also examines how to avoid such an eventuality, as well as how European TSOs should react in case a blackout occurs. Focused on the fast and reliable supply of consumers after a blackout, a novel restoration strategy based on the A* Algorithm is presented. Its efficiency is validated in the IEEE-39 and IEEE-68 bus systems. [ABSTRACT FROM AUTHOR]

An undeclared war has been going on in Ukraine for more than one year. Defeated at the front, Russia resorted to massive shelling of energy facilities with the aim of leaving Ukrainians without electricity and heat during the winter. As reported, since October 10, the Russians have fired more than a thousand missiles and drones at Ukrainian energy facilities. The shelling on November 23, 2022 led to a system crash — a blackout occurred. Forthe first time in the history of Ukraine, all of the country’s nuclear power units were shut down. In conditions of lack of light and non-working refrigerating chambers, the storage conditions of thermolabile immunobiological drugs became a new test for the medical community and patients. As you know, immunobiological drugs, which are widely used in the treatment of various rheumatological diseases, require strict storage conditions in the temperature range from +2 to +8 °С. Under blackout conditions, it is difficult for Ukrainian patientsto maintain optimal storage conditions for these drugs. The analysis of the studies showed that the majority of patients do not comply with the requirements for the storage of thermolabile drugs, even with the constant presence of light and electricity. Experts indicate that more and more thermolabile drugs are becoming available, and in most cases, these medications are dispensed to ambulatory patients. More thermolabile drugs are becoming available, and in most cases, these medications are dispensed to ambulatory patients. However, there is no regulation once medications are dispensed to patients and little is known with regard to what happens during transport and home storage. Previous studies suggest that these drugs are improperly stored. Future studies should focus on clinical consequences and possible solutions. It is recommended for Ukrainians to follow the rules and conditions of storage of heat-labile medicinal products during blackouts/emergency and stabilization blackouts. [ABSTRACT FROM AUTHOR]

Objective: The role of simultaneous alcohol and marijuana (SAM) use in the experience of blackouts among college students is unclear. To clarify discrepancies, the current study evaluated whether the association between SAM user status and blackouts was moderated by high-intensity drinking (HID). Participants and Methods: College students (N = 1,224; 63.7% female) reported on their past year experiences of blackout, marijuana use, SAM use, and HID (i.e., drinking at least twice the binge threshold). Results: SAM users had more past year blackouts than non-SAM users, but this effect was only significant among SAM users who had engaged in HID in the past year (nonbinge: F(5,37) = 0.50, p = 0.49; binge: F(5,138) = 0.23, p = 0.63; HID: F(5,328) = 4.52, p = 0.03). Conclusions: Effects of SAM user status on the experience of alcohol-related blackouts may be limited to individuals who engage in HID. [ABSTRACT FROM AUTHOR]

The usual operation of a microgrid (MG) may often be challenged by emergencies related to extreme weather conditions and technical issues. As a result, the operator often needs to adapt the MG's management by either: (i) excluding disconnected components, (ii) switching to islanded mode or (iii) performing a black start, which is required in case of a blackout, followed by either direct reconnection to the main grid or islanded operation. The purpose of this paper is to present an optimal Decision Support System (DSS) that assists the MG's operator in all the main possible sorts of emergencies, thus providing an inclusive solution. The objective of the optimizer, developed in Pyomo, is to maximize the autonomy of the MG, prioritizing its renewable production. Therefore, the DSS is in line with the purpose of the ongoing energy transition. Furthermore, it is capable of taking into account multiple sorts of Distributed Energy Resources (DER), including Renewable Energy Sources (RES), Battery Energy Storage Systems (BESS)—which can only be charged with renewable energy—and local, fuel-based generators. The proposed DSS is applied in a number of emergencies considering grid-forming and grid-following mode, in order to highlight its effectiveness and is verified with the use of PowerFactory, DIgSILENT. [ABSTRACT FROM AUTHOR]

A power grid in a nation or continent integrates utilities by generating stations and loads in order to meet power requirements. When such colossal power systems are involved in the transfer of power, the voltage stability issue typically crops up. Voltage collapse may lead to blackouts. Blackouts can only be reduced by focusing on the steady-state and dynamic operation of power systems. A possible solution may be to increase the power system infrastructure in order to endure these blackouts. Therefore, we need to distinguish the weak and less reliable buses or lines as soon as possible in the operation of the power system so that necessary actions can be taken for smooth operation or maintaining steady-state equilibrium. The weak elements may suffer outages, and that may lead to cascading outages. In this study, contingency ranking is carried out using two evaluation approaches, namely a pre-developed Fast Voltage Stability Index (FVSI) and a new Reduced Fast Voltage Stability Index (RFVSI) or the classical approach and the soft computing approach based on Fuzzy Logic (FL). The methods have been used for different bus systems such as IEEE-14, IEEE-30, and a practical Indian 62 bus system. The RFVSI is a reduced and faster version of FVSI. The outcomes of the two approaches were compared. It is found that the Fuzzy Logic (FL) approach computes the contingency ranking faster compared to the classical approaches, whereas the classical approach based on the RFVSI method calculates more correctly the contingencies and reliable results are produced. [ABSTRACT FROM AUTHOR]

After any major blackout, recreating the exact scene is one of the crucial but foundation steps in postmortem analysis. This helps in identifying and understanding the exact causes and sequence of events to avoid such failures in the future. Rather, power system restoration demands critical skills which involves deployment of appropriate strategies based on information about various factors, notably the extent and duration of the blackout, location of black-started units, interconnections with neighbouring systems, generator capabilities, and selecting appropriate restoration paths. The actual execution of the restoration plan consists of many surprises of unique nature and a lot of learning’s to avoid future occurrences of such incidents. The restoration efforts and failure of Mumbai grid failure on October 12, 2020, are highlighted in this paper. The paper first proposes formulating the dynamic models to get a better insight of the restoration process in the event of critical issues during this incident. The various challenges faced in systematic recovery of such a large system and lessons learnt from it forms focus of the paper. The paper also discusses factors not covered in existing literature, such as weather, fuel availability, and water mass oscillations which plays an important role in the restoration. [ABSTRACT FROM AUTHOR]

Power systems are exposed to various physical threats due to extreme events, technical failures, human errors, and deliberate damage. Physical threats are among the most destructive factors to endanger the power systems security by intelligently targeting power systems components, such as Transmission Lines (TLs), to damage/destroy the facilities or disrupt the power systems operation. The aim of physical attacks in disrupting power systems can be power systems instability, load interruptions, unserved energy costs, repair/displacement costs, and even cascading failures and blackouts. Due to dispersing in large geographical areas, power transmission systems are more exposed to physical threats. Power systems operators, as the system defenders, protect power systems in different stages of a physical attack by minimizing the impacts of such destructive attacks. In this regard, many studies have been conducted in the literature. In this paper, an overview of the previous research studies related to power systems protection against physical attacks is conducted. This paper also outlines the main characteristics, such as physical attack adverse impacts, defending actions, optimization methods, understudied systems, uncertainty considerations, expansion planning, and cascading failures. Furthermore, this paper gives some key findings and recommendations to identify the research gap in the literature. [ABSTRACT FROM AUTHOR]

The article is focused on the issue of blackouts in a water industry and the selection of a renewable energy source for a water treatment plant. In the case of power outage, it is necessary to constantly ensure the supply of a drinking water, if this requirement would not be met, it could cause of deterioration of hygiene and health of the population. To be able to convey drinking water during a blackout, it is mandatory to have a backup power supply. The state of the current water treatment plants in the Czech Republic is that they are using diesel generators as backup power supply, which causes air pollution. There are other options of power supply that can be used, such as renewable energy sources. By using a multi-criteria analysis method, renewable energy sources were analyzed for a water treatment plant in the selected region. Based on the results, it seems that the most suitable choice is a small hydro power plant at the entry points of water treatment plant. Other possibilities of renewable energy sources that may be suitable for a water treatment plant and the usage of a multi-criteria analysis method for a water treatment plant in other countries are also discussed. [ABSTRACT FROM AUTHOR]

The article concerns the energy security of a wastewater treatment process caused by unforeseen situations related to the risk of electrical power outages. In this case, renewable energy sources based on distributed generation power systems can solve this problem in each wastewater treatment plant. The article highlights e related challenges and proposes the direction of solutions in this regard based on Czech conditions. The first part of the paper deals with the consequences of long-term outage of wastewater treatment plants on the population and the environment. There are several solutions presented for blackout conditions, and model calculations are made based on data from a Czech wastewater treatment plant. Diesel engine-generators, biogas as a cogeneration source of heat and electricity, solar panels with storage systems and combined biogas and solar systems were considered as approaches to provide energy autonomy during a blackout in a wastewater treatment plant. Special attention was paid to a combination of CHP units with solar panels and batteries. The results were evaluated for three different locations for this combination. It was concluded that biogas combustion in the CHP unit was the most profitable option, allowing the production of electricity independently of the grid for its own consumption and possibly for other operations. The last part of the paper deals with the transition to island operation, which must occur during a blackout. This transition is more difficult for both solar panels and cogeneration units if they were to supply electricity to the grid before a blackout. The transition to energy island operation could be ensured by frequency relay and processor devices to control the circuit breaker. Then, to maintain island operation, it would be necessary to have an automatic load shedding/application system. [ABSTRACT FROM AUTHOR]

A disaster may not necessarily demolish the telecommunications infrastructure, but instead it might affect the national grid and cause blackouts, consequently disrupting the network operation unless there is an alternative power source(s). In disaster-resilient networks, fiber cut, datacenter destruction, and node isolation have been studied before with different scenarios, but the power outage impact has not been investigated before. In this paper, power outages are considered, and the telecommunication network performance is evaluated during a blackout. A mixed Integer Linear Programming (MILP) model is developed to evaluate the network performance for a single node blackout under two scenarios: minimization of blocking and minimization of renewable and battery energy consumption. Insights analyzed from the MILP model results have demonstrated the trade-off between the two evaluated optimization cost functions and shown that the proposed scheme can extend the network lifetime while minimizing the required amount of backup energy. [ABSTRACT FROM AUTHOR]

Background: Alcohol‐induced blackouts describe memory loss resulting from alcohol consumption. Approximately half of college students report experiencing a blackout in their lifetime. Blackouts are associated with an increased risk for negative consequences, including serious injury. Research has documented two types of blackouts, en bloc (EB) and fragmentary (FB). However, research is limited by the lack of a validated measure that differentiates between these two forms of blackout. This study used a mixed‐methods approach to improve the assessment of FB and EB among young adults. Specifically, we sought to improve the existing Alcohol‐Induced Blackout Measure (ABOM), which was derived from a relatively small pool of items that did not distinguish FB from EB. Methods: Study 1 used three rounds of cognitive interviewing with U.S. college students (N = 31) to refine existing assessment items. Nineteen refined blackout items were retained for Study 2. Study 2 used face validity, factor analysis, item response theory, and external validation analyses to test the two‐factor blackout model among U.S. heavy‐drinking college students (N = 474) and to develop and validate a new blackout measure (ABOM‐2). Results: Iterative factor analyses demonstrated that the items were well represented by correlated EB and FB factors, consistent with our hypothesis. External validation analyses demonstrated convergent and discriminant validity. These analyses also provided preliminary evidence for the two factors having differential predictive validity (e.g., FB correlated with enhancement drinking motives, while EB correlated with coping and conformity motives). Conclusions: The Alcohol‐Induced Blackout Measure‐2 (ABOM‐2) improves the measurement of blackout experiences among college students. Its use could facilitate the examination of EB and FB as differential predictors of alcohol‐related outcomes in future studies. [ABSTRACT FROM AUTHOR]

In recent years, the occurrence of cascading failures and blackouts arising from cyber intrusions in the underlying configuration of power systems has increasingly highlighted the need for effective power management that is able to handle this issue properly. Moreover, the growing use of renewable energy resources demonstrates their irrefutable comparative usefulness in various areas of the grid, especially during cascading failures. This paper aims to first identify and eventually protect the vulnerable areas of these systems by developing a hybrid structure-based microgrid against malicious cyber-attacks. First, a well-set model of system vulnerability indices is presented to indicate the generation unit to which the lines or buses are directly related. Indeed, we want to understand what percentage of the grid equipment, such as the lines, buses, and generators, are vulnerable to the outage of lines or generators arising from cyber-attacks. This can help us make timely decisions to deal with the reduction of the vulnerability indices in the best way possible. The fact is that employing sundry renewable resources in efficient areas of the grid can remarkably improve system vulnerability mitigation effectiveness. In this regard, this paper proposes an outstanding hybrid-energy framework of AC/DC microgrids made up of photovoltaic units, wind turbine units, tidal turbine units, and hydrogen-based fuel cell resources, all of which are in grid-connect mode via the main grid, with the aim to reduce the percentage of the system that is vulnerable. To clearly demonstrate the proposed solution's effectiveness and ease of use in the framework, a cyber-attack of the false data injection (FDI) type is modeled and developed on the studied system to corrupt information (for instance, via settings on protective devices), leading to cascading failures or large-scale blackouts. Another key factor that can have a profound impact on the unerring vulnerability analysis concerns the uncertainty parameters that are modeled by the unscented transform (UT) in this study. From the results, it can be inferred that vulnerability percentage mitigation can be achieved by the proposed hybrid energy framework based on its effectiveness in the system against the modeled cyber-attacks. [ABSTRACT FROM AUTHOR]

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Given the frequency of power outages caused by recent crises, including high-impact natural disasters, power and energy supply must be more resilient and cost effective. Owing to this necessity, this article presents a grid-connected multicarrier energy microgrid, which can provide continuous energy for both electrical and heating load demands at a low cost. The model employs a demand response (DR) scheme based on time of use and integrates with the proposed microgrid. Several energy sources—photovoltaics, batteries, a combined heat and power unit, and associated dispatch strategy—are optimized using the deterministic mixed-integer linear programming algorithm. The proposed model is tested in a hospital of California, USA. The results show the benefits of the DR program in terms of techno-economic output when compared to the system without its implementation. Several simulation results also demonstrate the model’s effectiveness and resiliency in maintaining a continuous energy supply in the midst of power outages at various times of the year while lowering costs. Furthermore, a comparative study with the existing methods is performed, which shows the effectiveness of the proposed technique as well. [ABSTRACT FROM AUTHOR]

Propagation characteristics of obliquely incident terahertz waves in high-temperature magnetized plasma are studied by the scattering matrix method (SMM) and Wentzel–Kramers–Brillouin (WKB) method. Three cases of electron density distribution (uniform, double exponential, and Epstein distributions) are considered. Numerical simulation exhibits that the SMM can give out the nearly same results with the WKB method, which indicates that these two methods work very well for solving this problem. Through the analysis of the incident angle, we found that as the incident angle increases, it is not conducive to the transmission of left-handed circularly polarized (LCP) waves and right-handed circularly polarized (RCP) waves. When the incident angle increases to a certain value, the phenomenon of “total reflection” will appear. We also systematically calculated the influence of physical parameters such as electron density, collision frequency, plasma thickness, magnetic field strength, and electron temperature on the transmission characteristics. These theoretical results are helpful to alleviate “blackout” problem and improve communication quality. [ABSTRACT FROM AUTHOR]

This review article puts forward the phenomena of chaotic oscillation in electrical power systems. The aim is to present some short summaries written by distinguished researchers in the field of chaotic oscillation in power systems. The reviewed papers are classified according to the phenomena that cause the chaotic oscillations in electrical power systems. Modern electrical power systems are evolving day by day from small networks toward large-scale grids. Electrical power systems are constituted of multiple inter-linked together elements, such as synchronous generators, transformers, transmission lines, linear and nonlinear loads, and many other devices. Most of these components are inherently nonlinear in nature rendering the whole electrical power system as a complex nonlinear network. Nonlinear systems can evolve very complex dynamics such as static and dynamic bifurcations and may also behave chaotically. Chaos in electrical power systems is very unwanted as it can drive system bus voltage to instability and can lead to voltage collapse and ultimately cause a general blackout. [ABSTRACT FROM AUTHOR]

Under-frequency load shedding (UFLS) appears to be an effective approach to preventing cascading outages that includes various methods. In recent years, much research has been done in the field of dynamic schemes. However, these schemes are less commonly used due to their disadvantages such as the inability to calculate the optimal shed load amount, the need to additional relays or communication infrastructures, etc. In contrast, static UFLS schemes are more common due to their simplicity, efficiency, fast implementation, as well as the unnecessity of additional equipment. However, how to determine the load shedding (LS) location and amount in static methods seems to be still challenging. Furthermore, conventional methods have a major drawback because of over shedding. In order to solve this problem, in this paper, a new static method is proposed to determine the location and amount of optimal LS based on co-simulation of DIgSILENT and MATLAB software. The system dynamics is simulated in DIgSILENT and optimization using imperialist competitive algorithm (ICA) runs in MATLAB. This co-simulation makes it possible to take advantage of both pieces of software. The results of the simulation on the IEEE 39-Bustest system in several scenarios clearly demonstrate the efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, a coupled interaction matrix is proposed to describe the interactions between line outages and the load shed at buses. The coupled interaction matrix is effectively estimated by the Expectation Maximization algorithm. A highly probabilistic coupled interaction model is further proposed to efficiently generate cascades with both line outages and the load shed based on the coupled interaction matrix and the distribution of initial outages. To mitigate cascading failures, critical links are identified based on the coupled interaction matrix by calculating a comprehensive severity index that considers the consequences of both line outages and the load shed. Simulation results on the IEEE 300-bus system verify the effectiveness of the proposed approach. The cascades generated from the coupled interaction model match the statistics of the original cascades very well. The identified critical links based on the comprehensive severity index enable a proper tradeoff between reducing line outages and reducing the load shed, leading to a better mitigation effect than only considering either line outages or the load shed. [ABSTRACT FROM AUTHOR]

Breath-hold diving (freediving) is an underwater sport that is associated with elevated hydrostatic pressure, which has a compressive effect on the lungs that can lead to the development of pulmonary edema. Pulmonary edema reduces oxygen uptake and thereby the recovery from the hypoxia developed during freediving, and increases the risk of hypoxic syncope. We aimed to examine the efficacy of SpO2, via pulse-oximetry, as a tool to detect pulmonary edema by comparing it to lung ultrasound B-line measurements after deep diving. SpO2 and B-lines were collected in 40 freedivers participating in an international deep freediving competition. SpO2 was measured within 17 ± 6 min and lung B-lines using ultrasound within 44 ± 15 min after surfacing. A specific symptoms questionnaire was used during SpO2 measurements. We found a negative correlation between B-line score and minimum SpO2 (r s = −0.491; p = 0.002) and mean SpO2 (r s = −0.335; p = 0.046). B-line scores were positively correlated with depth (r s = 0.408; p = 0.013), confirming that extra-vascular lung water is increased with deeper dives. Compared to dives that were asymptomatic, symptomatic dives had a 27% greater B-line score, and both a lower mean and minimum SpO2 (all p < 0.05). Indeed, a minimum SpO2 ≤ 95% after a deep dive has a positive predictive value of 29% and a negative predictive value of 100% regarding symptoms. We concluded that elevated B-line scores are associated with reduced SpO2 after dives, suggesting that SpO2 via pulse oximetry could be a useful screening tool to detect increased extra-vascular lung water. The practical application is not to diagnose pulmonary edema based on SpO2 – as pulse oximetry is inexact – rather, to utilize it as a tool to determine which divers require further evaluation before returning to deep freediving. [ABSTRACT FROM AUTHOR]

Objective: To explore patients' long-term experiences with drinking alcohol after Roux-n-Y gastric bypass (RYGB) for conceptualizing what may indicate problematic drinking behavior after bariatric surgery. Study Design: Three-center, observational study. Patients: 546 adult patients undergoing RYGB in the period 2003-2009 in Norway. Main Outcome Measures: Self-reported data on drinking behavior and experiences related to alcohol collected 10-15 years after surgery. Results: Out of the 959 patients undergoing RYGB in the period, 29 were diseased and 546 participated in this follow-up study (58.7%). Focusing on suspicious changes in drinking behavior, 8.8% reported drinking more, 11.5% consumed alcohol at least twice a week, and 10.6% consumed at a minimum of 6 units of alcohol at a frequency of at least once monthly. The nature of hangovers had changed for about a third of the patients, with 21.6% reporting these to feel weaker or absent. Repeated alcoholic blackouts were reported by 11.9%. A subgroup of the patients were categorized as displaying presumed problematic drinking behavior(PPDB). Among the PPDB-men there was a significant association to having had a fall last year (6 (100.0%) PPDB-patients vs. 30 (29.7%) non-PPDB, p<.001). Among the PPDB-women, there was a significant association to having had alcohol problems prior to surgery (7 (70.0%) PPDB-patients vs. 67 (17.7%) non-PPDB, p<.001). Less significant associations to PPDB reported for explorative purposes were lack of patient education (men) (16 (26.2%) PPDB-patients vs. 8 (61.5%) non-PPDB, p=.014); more than 3 months persistent musculoskeletal pain (women) (45 (15.3%) PPDB-patients vs. 29 (24.6%) non-PPDB, p=.026); subjective problems with memory (women) (58 (20.7%) PPDB-patients vs. 10 (9.1%) non-PPDB, p=.006); and, receiving professional help for mental problems last 12 months (women) (29 (22.7%) PPDB-patients vs. 45 (14.7%) non-PPDB, p=.043). Conclusion: A subset of patients display drinking behaviors that may be consistent with postsurgical alcohol problems. Screening instruments like AUDIT may not be sufficiently specific to capture several risk behaviors occurring after bariatric surgery. [ABSTRACT FROM AUTHOR]

The aim of the research described in the article is to examine the options of addressing power supply disruption in the selected sectors of infrastructure due to emergency situation: snowfall in the area of Český Krumlov and Prachatice districts in the Czech Republic on April 28, 2017. Based on the characteristics of climatic, meteorological and geographic data, consequences of power supply disruption are described with emphasis on the approach of the electricity distributor and the affected infrastructure (transport and communication networks - mobile operators) in selected sectors. Reflection on the intervention activities of the Fire Rescue Service units in making roads passable has been carried out. The article evaluates preparedness and intervention activities based on the case study of emergency situation management procedures related to the selected infrastructure and suggests recommendations for their improvement. [ABSTRACT FROM AUTHOR]

Diesel–Electric Propulsion (DEP) has been widely used for the propulsion of various ship types including cruise ships. Considering the potential consequences of blackouts, especially on cruise ships, it is essential to design and operate the ships’ power plants for avoiding and preventing such events. This study aims at implementing a comprehensive safety analysis for a cruise ship Diesel– Electric Propulsion (DEP) plant focusing on blackout events. The Combinatorial Approach to Safety Analysis (CASA) method is used to develop Fault Trees considering the blackout as the top event, and subsequently estimate the blackout frequency as well as implement importance analysis. The derived results demonstrate that the overall blackout frequency is close to corresponding values reported in the pertinent literature as well as estimations based on available accident investigations. This study deduces that the blackout frequency depends on the number of operating Diesel Generator (DG) sets, the DG set’s loading profile, the amount of electrical load that can be tripped during overload conditions and the plant operation phase. In addition, failures of the engine auxiliary systems and the fast-electrical load reduction functions, as well as the power generation control components, are identified as important. This study demonstrates the applicability of the CASA method to complex marine systems and reveals the parameters influencing the investigated system blackout frequency, thus providing better insights for these systems’ safety analysis and enhancement. [ABSTRACT FROM AUTHOR]

Twitter provides a real-time venue for monitoring alcohol consumption and negative alcohol-related consequences. "Blackouts," defined as events involving alcohol-induced amnesia, are commonly endorsed among social drinkers. However, the term "blackout" has been used in popular culture to describe being intoxicated. We qualitatively examined the content of alcohol-related blackouts posts ("Tweets") on Twitter, focusing on reflections post-drinking that involved clear references to memory loss. We examined publically available Tweets that referenced blackouts after an alcohol consumption event (n = 3,574). Twitter represents a relatively unfiltered glimpse at reflections on alcohol-induced amnesia. As hypothesized, most tweets referencing blackouts did not clearly describe amnesia. In the Tweets that clearly reference amnesia, we identified several themes. Tweeters referenced an 'AlterEgo' who was responsible for all the intoxicated behaviors that were inconsistent with the Tweeter's personality. Additionally, the Tweets discussed ways in which the drinker recovered memories (e.g. from friends, from social media), other events that occurred during the amnesia (e.g. loss of items, help from friends, sexual experiences), and regret about having lost memories. Some Tweeters requested assistance from their followers to reconstruct their drinking event. Tweets have the potential to set norms about acceptable behaviors or scripts following a blackout. Since most blackout Tweets are ambiguous with regards to alcohol-induced amnesia, these Tweets might be leading people to believe that blackouts are passing out or just periods of heavy intoxication. In addition, themes from these Tweets can inform future interventions by using the cognitions surrounding this high-risk behavior. [ABSTRACT FROM AUTHOR]