Solving congestions with pumped hydro storage under high penetration of renewable energy in Vietnam: The case of Ninh Thuan HV grid

Renewable energy sources are increasingly penetrating all power networks worldwide, despite the security status of these networks threatened by the fickle nature of these sources. Ninh Thuan Province (Vietnam) experienced a solar power boom in 2019–2021 and, with it, the congestion of both the local transmission and distribution networks. To solve congestions and operational security issues, large-scale storage solutions were considered and, due to land availability, Pumped Hydro Storage (PHS) technology was selected to solve these problems. However, the operational risks of cascade outage when integrating both renewables and a PHS system needs to be carefully considered, especially in a bulk power system. For this reason, this study examined the potential of integrating a large-scale grid-connected PHS system in ensuring operational security against the impacts of solar power plants in Ninh Thuan. The analyses of static and dynamic security were carried out for scenarios with and without the PHS system, including under current operational conditions. The results of the simulations show that the presence of the PHS improves both static and dynamic performance of the system, thus allowing full exploitation of solar power and avoiding curtailment. NEPLAN environment was chosen to simulate all scenarios under the Vietnamese grid code

Critical Assessments of the Potential for Integrating Renewable Energy into Isolated Grids on Vietnamese Islands: The Case of the An-Binh Grid

Renewable electricity for off-grid areas is widely seen as one of the top choices in supporting local economic development in most countries, and so is Vietnam. Over the years, many isolated networks using renewable energy sources have been deployed for off-grid areas in Vietnam. However, the use of these energy sources in Vietnam’s isolated networks is still facing many challenges due to its infancy here. The issues of reliability and vulnerability of these networks are not given the expected attention. Another challenge is that the issues of the operational security of these systems could also be negatively affected by the variable nature of renewable sources, including static and dynamic security. For this reason, this study aims to contribute to a better understanding of integrating renewable energy into isolated networks, and in this case, using solar power for the An-Binh Island grid in Vietnam. The findings from this study suggest that choosing the right structure of the power mix could contribute to improving the operational security of isolated networks. Moreover, several solutions to enhance the reliability of this grid are also proposed. The NEPLAN environment was selected for simulation and analysis for all the scenarios in this study

Evaluation Of Elastic Modulus And Stress Gradient Of PECVD Silicon Nitride Thin Films

This study investigated the techniques for determining the elastic modulus and estimating the stress gradient of plasma-enhanced chemical vapor deposition (PECVD) silicon nitride thin films. The experimentally determined elastic modulus was then used in a finite element beam model to compute the stress distribution inside the thin films using a commercial finite element analysis package. The computed beam displacement caused by a given stress gradient was compared with the displacement experimentally evaluated using optical interference microscopy. This comparison allows the stress gradient of the PECVD silicon nitride membrane introduced by the fabrication process to be evaluated

Study on cosmogenic activation above ground for the DarkSide-20k project

The activation of materials due to the exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k is a direct detection experiment for galactic dark matter particles, using a two-phase liquid argon time projection chamber filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the argon and other massive components of the set-up has been estimated; production of 120 t of radiopure UAr is foreseen. The expected exposure above ground and production rates, either measured or calculated, have been considered. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. Activation of titanium, considered in early designs but not used in the final design, is discussed. The activity of 39Ar induced during extraction, purification and transport on surface, in baseline conditions, is evaluated to be 2.8% of the activity measured in UAr from the same source, and thus considered acceptable. Other products in the UAr such as 37Ar and 3H are shown to not be relevant due to short half-life and assumed purification methods

Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

<p>Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.</p> <p>Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.</p> <p>Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.</p&gt

Adherence to antibiotic treatment guidelines and outcomes in the hospitalized elderly with different types of pneumonia

Background: Few studies evaluated the clinical outcomes of Community Acquired Pneumonia (CAP), Hospital-Acquired Pneumonia (HAP) and Health Care-Associated Pneumonia (HCAP) in relation to the adherence of antibiotic treatment to the guidelines of the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS) in hospitalized elderly people (65 years or older). Methods: Data were obtained from REPOSI, a prospective registry held in 87 Italian internal medicine and geriatric wards. Patients with a diagnosis of pneumonia (ICD-9 480-487) or prescribed with an antibiotic for pneumonia as indication were selected. The empirical antibiotic regimen was defined to be adherent to guidelines if concordant with the treatment regimens recommended by IDSA/ATS for CAP, HAP, and HCAP. Outcomes were assessed by logistic regression models. Results: A diagnosis of pneumonia was made in 317 patients. Only 38.8% of them received an empirical antibiotic regimen that was adherent to guidelines. However, no significant association was found between adherence to guidelines and outcomes. Having HAP, older age, and higher CIRS severity index were the main factors associated with in-hospital mortality. Conclusions: The adherence to antibiotic treatment guidelines was poor, particularly for HAP and HCAP, suggesting the need for more adherence to the optimal management of antibiotics in the elderly with pneumonia

Routine coagulation testing in intensive care

© 2016, Australasian Medical Publishing co. All Rights Reserved.Objective: To test a simple clinical guideline to reduce unnecessary routine testing of coagulation status. Design, setting and participants: A prospective, unblinded, observational study of coagulation testing frequency before and after introduction of a simple clinical guideline. We included 253 patients admitted to a tertiary intensive care unit: 100 patients consecutively enrolled before our intervention (May - July 2015) and 153 patients consecutively enrolled after our intervention (August - September 2015). Intervention: We introduced a clinical guideline and educational program in the ICU from 18 August 2015. Main outcome measures: The number of coagulation tests performed per patient bed-day, and the associated pathology costs. Results: Over the 3-month sample period, 999 coagulation profiles were performed for 253 patients: 720 (72%) in 100 patients before, and 279 (28%) in 153 patients after our intervention. The testing frequency fell from 1.12 to 0.41 per patient bed-day (P < 0.001). A total of 463 pre-intervention coagulation profiles (64%) were classified as unnecessary, and the cost of all coagulation tests fell by 60.5% per bed-day after the intervention. Conclusion: A simple clinical guideline and educational package reduced unnecessary coagulation tests and costs in a tertiary referral ICU