The objective of a power system is to provide electricity to its customers as economically as possible with an acceptable level of reliability while safeguarding the environment. Power system ...reliability assessments are routinely performed to ensure adequate system resources and reliable operation using well-established methods, quantitative metrics, regulatory standards and compliance incentives in the jurisdictions of responsibilities. The alarming increase in the occurrence of extreme events, which are not included in routine reliability evaluation, has raised growing concerns due to the catastrophic impacts of these events on distribution systems. The potential economic losses due to prolonged and large-scale outages have motivated utility planners, operators and policy makers to acknowledge the importance of system resiliency against such events. Power system resiliency, however, lacks widely accepted modeling frameworks, standards, assessment methods and metrics. This paper presents a resilience assessment framework, along with quantifiable metrics to assess the resiliency of a distribution system against extreme winds, which are among the most common form of natural disasters affecting the North American region. The paper assesses the effectiveness of infrastructural and operational resilience enhancement strategies. The effectiveness of preventive and corrective strategies is also analyzed on a test distribution system.
Wind energy application in electric power systems continues to increase globally. The contribution of wind farms to the overall system reliability is limited by the uncertainty in power output from ...these highly variable energy sources. The ability of a power system to absorb available wind energy and maintain the system reliability and stability is reduced as the wind penetration in the system is increased. It therefore becomes important to coordinate the operation of wind power with fast responding conventional generating units. Hydro facilities with energy storage capability can alleviate the impact of wind power fluctuations and also contribute to system adequacy. A methodology for an energy limited hydro plant and wind farm coordination is developed using a Monte Carlo simulation technique considering the chronological variation in the wind, water and the energy demand. The IEEE four-state model is incorporated in the developed technique to recognize the intermittent operation of hydro units. The proposed approach is applied to the IEEE-RTS, and quantitative assessment of reliability benefits from effective utilization of wind and water resources are conducted through a range of studies. The effects of major system parameters on the system adequacy are also investigated.
Renewable energy resources like wind generation are being rapidly integrated into modern power systems. Energy storage systems (ESS) are being viewed as a game-changer for renewable integration due ...to their ability to absorb the variability and uncertainty arising from the wind generation. While abundant literature is available on system adequacy and operational reliability evaluation, operational adequacy studies considering wind and energy storage have received very little attention, despite their elevated significance. This work presents a novel framework that integrates wind power and energy storage models to a bulk power system model to sequentially evaluate the operational adequacy in the operational mission time. The analytical models are developed using a dynamic system state probability evaluation approach by incorporating a system state probability estimation technique, wind power probability distribution, state enumeration, state transition matrix, and time series analysis in order to quantify the operational adequacy of a bulk power system integrated with wind power and ESS. The loss of load probability (LOLP) is used as the operational adequacy index to quantify the spatio-temporal variation in risk resulting from the generation and load variations, their distribution on the network structure, and the operational strategies of the integrated ESS. The proposed framework is aimed to serve as a guideline for operational planning, thereby simplifying the decision-making process for system operators while considering resources like wind and energy storage facilities. The methodology is applied to a test system to quantify the reliability and economic benefits accrued from different operational strategies of energy storage in response to wind generation and other operational objectives in different system scenarios.
SHP2 is a nonreceptor protein tyrosine phosphatase (PTP) encoded by the PTPN11 gene involved in cell growth and differentiation via the MAPK signaling pathway. SHP2 also purportedly plays an ...important role in the programmed cell death pathway (PD-1/PD-L1). Because it is an oncoprotein associated with multiple cancer-related diseases, as well as a potential immunomodulator, controlling SHP2 activity is of significant therapeutic interest. Recently in our laboratories, a small molecule inhibitor of SHP2 was identified as an allosteric modulator that stabilizes the autoinhibited conformation of SHP2. A high throughput screen was performed to identify progressable chemical matter, and X-ray crystallography revealed the location of binding in a previously undisclosed allosteric binding pocket. Structure-based drug design was employed to optimize for SHP2 inhibition, and several new protein–ligand interactions were characterized. These studies culminated in the discovery of 6-(4-amino-4-methylpiperidin-1-yl)-3-(2,3-dichlorophenyl)pyrazin-2-amine (SHP099, 1), a potent, selective, orally bioavailable, and efficacious SHP2 inhibitor.
Objective: Child marriage is a detrimental practice with negative consequences for girls' health and well-being. This study aims to identify the prevalence of child marriage and associated risk ...factors within the Madhesi community. Materials and methods: A cross-sectional study was conducted in a sub-metropolitan city of Lumbini Province, Nepal, in 2023. A total of 352 married women were randomly selected using simple random sampling and interviewed using a structured questionnaire between March 28th and April 17th. Descriptive categorical variables were expressed as proportions. Risk factors associated with child marriage were measured using the Chi-square test and multivariate logistic regression analysis. All statistical analyses were performed using SPSS version 26. Results: The majority of respondents (36.1%) were in the age group 21-25, with a mean age of 25.90 years ± 4.6 years. Most respondents (48.9%) received only basic-level education, with the majority (72.4%) reporting their parents as having no formal education. The primary family occupation was farming (40.1%). The prevalence of child marriage was high (77.0%), with a median marriage age of 18 years. Logistic regression analysis revealed significant risk factors including lower education levels of respondents and their parents, husband's occupation, lack of awareness about the legal marriage age, limited decision-making power regarding marriage, belief in the dowry system, discussions with friends about child marriage, and occurrence of child marriage among friends. Conclusion: Despite legal prohibition, child marriage remains prevalent in the Madhesi community. Educational interventions targeting women and parents, empowering women with decision-making authority, and addressing the dowry system are crucial for reducing this harmful practice.
The contribution of solar power in electric power systems has been increasing rapidly due to its environmentally friendly nature. Photovoltaic (PV) systems contain solar cell panels, power electronic ...converters, high power switching and often transformers. These components collectively play an important role in shaping the reliability of PV systems. Moreover, the power output of PV systems is variable, so it cannot be controlled as easily as conventional generation due to the unpredictable nature of weather conditions. Therefore, solar power has a different influence on generating system reliability compared to conventional power sources. Recently, different PV system designs have been constructed to maximize the output power of PV systems. These different designs are commonly adopted based on the scale of a PV system. Large-scale grid-connected PV systems are generally connected in a centralized or a string structure. Central and string PV schemes are different in terms of connecting the inverter to PV arrays. Micro-inverter systems are recognized as a third PV system topology. It is therefore important to evaluate the reliability contribution of PV systems under these topologies. This work utilizes a probabilistic technique to develop a power output model for a PV generation system. A reliability model is then developed for a PV integrated power system in order to assess the reliability and energy contribution of the solar system to meet overall system demand. The developed model is applied to a small isolated power unit to evaluate system adequacy and capacity level of a PV system considering the three topologies.
Background: Road traffic accidents (RTAs) are a leading and disproportionately prevalent cause of mortality and disability, particularly burdening Nepal, primarily within the Kathmandu Valley.
...Methods: This cross-sectional study was conducted between March 22nd and April 24th, 2021, involving 185 victims admitted to the emergency department of a private hospital. Respondents were selected using purposive sampling, and data were collected through face-to-face interviews. Socio-demographic characteristics, human factors, and environmental factors data were analyzed using descriptive statistics, and all statistical tests were conducted using SPSS version 20.
Results: Among the 185 RTA victims, the majority (36.8%) fell within the 21-30 age groups. Male victims (55.7%) outnumbered females (44.3%). Students (36.8%) experienced the highest accident rates, with most incidents (21.1%) occurring on Saturdays and 38.4% taking place between 12:00pm and 6:00pm.
Human Factors and RTA: Of the total victims, 80 (43.2%) were drivers, with 43.75% of them reporting the use of emergency brakes. Furthermore, 77.61% indicated that accidents were caused by pedestrians not using zebra crossings when crossing the road.
Environmental Factors and RTA: Rainy weather was associated with the highest number of accidents, accounting for 36.2% of cases. Additionally, narrow routes (28.6%) and slippery roads (25.9%) contributed to a significant number of accidents.
Conclusion: Nepal faces a high rate of road traffic accidents, with critical factors including victim age, vehicle types, speed, road and weather conditions, and traffic rule violations. Authorities must consider these factors to effectively control and prevent RTAs.
Introduction: Pesticides cause short-term as well as long-term health effects. Agriculture workers are at high risk of effect. So, this study aimed to identify the health effects of pesticides among ...small-scale farmers in the municipality of Bhaktapur, Nepal. Methods: This was a community-based cross-sectional descriptive study conducted in all wards of Changunarayan Municipality, Bhaktapur, Nepal. Farmers of selected households who adopted agriculture as their main occupation were included in this study. The sample size for the study was 132. Proportionate stratified sampling was used to determine the farmer from each ward and simple random sampling was used to reach every respondent. Face-to-face interview technique and semi-structured questionnaire was used for data collection. The data were analyzed using descriptive statistics and the Chi-square test was applied to measure an association between selected variables. Results: All of the farmers used pesticides and about two-thirds 74(64.9%) experienced both immediate as well as delayed symptoms due to the use of pesticides. Majority of them showed general symptoms such as eye irritation 87(76.3%), difficulty in breathing 70(61.4%) and fatigue 55(48.2%). There was an association between the frequency of exposure and health effects due to pesticide use which was found to be statistically significant at a significance level with p-value 0.042. Conclusion: Health effects such as skin rashes, effects on the eyes, and respiratory system were reported. The most prevalent effects were eye irritation, difficulty in breathing, and itching of the skin. Training on pesticide use and awareness should be conducted by municipalities to reduce the effects.
Rising uncertainty in power systems due to ongoing system and operational changes has led to increasing risks in operating a system in a reliable and economic manner. There are growing reliability ...concerns with the widely used methods, such as the N-1 criterion, to determine operating reserve requirement during unit commitment, and the economic load dispatch method to allocate regulating margin to respond to disturbances. These deterministic methods do not consider the uncertainty or stochastic nature of power systems and are often inadequate to maintain the required operating reliability of modern power systems. This paper introduces a reliability index, designated as the committed generators’ response risk (CGRR) that can be used to maintain a specified level of operating reliability. A probabilistic method to evaluate the CGRR is presented and validated using a Monte Carlo simulation technique. An application of the new index and the methodology is illustrated using the IEEE Reliability Test System. The CGRR provides a comprehensive operating risk measurement of the committed generation until further assistance is available to support the system, and therefore helps operators in decision making for unit commitment and dispatch of the generating units to meet the projected load in the short future time.
Objective:
To assess the level of knowledge and practice on malaria prevention among the residents of Ratuwamai Municipality in Nepal.
Methods:
A community-based cross-sectional study was carried out ...on Ratuwamai Municipality of Ward No. 8 in Morang District, Nepal. A total of 352 respondents with an age range from 15 to 70 years were interviewed from October 9 to October 31, 2022. Statistically significant differences between two or more categorical groups were measured using independent sample
t
-test, one-way ANOVA test, and Kruskal-Wallis
H
test.
Result:
Out of the total sample, 57.7% of the respondents were 24 to 50 years old with a mean age of (36.9±14.3) years. In the knowledge test, 82% of the responses were accurate. Though 98.6% of people had heard of malaria, only 48.3% said it was a communicable disease. In practice, 84.9% always cleaned the surrounding area and trimmed the bushes around the house; 75.9% used insecticide-treated bed nets or normal bed nets for sleeping; only 7.4% used mosquito repellent creams on exposed body parts while staying outdoors at night, working in fields, and sleeping.
Conclusions:
The majority had knowledge about malaria, but more than half had poor practice. We advise concerned authorities to promote the behavior change communication strategy to encourage individuals to adopt healthy, beneficial, and good behavioral practices.
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