Unit Capacity Research Articles

Scheduled power tracking control of the virtual power plant for its internal contingency considering the communication delay and the unit capacity limitation

Scheduled power tracking control of the virtual power plant for its internal contingency considering the communication delay and the unit capacity limitation

Availability and capacity of nutrition units in primary health centers in Sokoto State, North Western Nigeria

A cross sectional descriptive study was carried out in Primary Health Centers (PHCs) in Sokoto State to assess the availability of nutritional units in primary health care facilities in the state and their capacities. The target for the study were the in-charge of the sampled PHCs and nutrition units of the PHCs. The study PHCs were selected using the cluster sampling method. Data were collected using an interviewer-administered questionnaire and observer checklist. The study shows a lack of adequate demonstration kitchens and utensils in many PHCs, inappropriate, multitasking and poorly trained personnel. It is recommended that demonstration kitchens in the PHCs be revitalized and adequate staffing and training be provided for nutrition staff across the state.

DETERMINING THE ENERGY EFFICIENCY OF THE RIVER SECTION IN RELATIVE TERMS

Electricity production in Georgia heavily relies on the hydropower sector, making it crucial to develop and advance in this area to attain energy independence. Thus, this article presents an opinion on the potential of utilizing Georgia's hydropower resources. The article provides a quantitative criterion for determining the energy efficiency of the river section in relative terms, namely: following the corresponding river fall per unit, length of the river section, and the related water consumption per unit capacity. Accordingly, we will provide a practical example of evaluating a river section's energy efficiency using the mentioned criteria.

Improvement of melting performance in a longitudinal finned latent heat thermal energy storage unit

AbstractThis article presents an analysis and enhancement of the charging behavior of a double‐pipe LHTES unit with longitudinal fins for concentrated solar power applications using a finite element numerical analysis approach. The finite element approach is applied to this numerical analysis by using “COMSOL Multiphysics” software. The investigated LHTES system has an operating temperature range of 180°C‐300°C and uses “DelcoTerm Solar E 15” as the heat transfer fluid (HTF) with a eutectic inorganic mixture of sodium nitrite and sodium nitrate as the phase change material (PCM). While also taking into account the impact of the tube material and the number of fins, the primary goal of this study is to evaluate performance improvement by changing the thickness and number of fins in a linked manner without changing the storage unit capacity. The results show a maximal impact on thermal performance which decreased the melting time by 46% and the charging time by 49.6% for the configuration with a fin thickness of 1 mm, 27 longitudinal fins, an inner tube made of aluminum, and a mass flow rate of 60 kg/h.

Variation in mortality burden of the COVID-19 pandemic across federal states in Germany.

Intra-annual excess mortality is the most reliable measure of losses of lives due to short-term risk factors. The objectives of our study are (i) to estimate excess mortality across German states in the course of the coronavirus disease 2019 (COVID-19) pandemic years 2020 and 2021 and (ii) to identify possible regional-level determinants of spatial inequality in pandemic-related excess mortality. We use weekly mortality data series for the calculation of weekly death rates, standardized by age for each federal state of Germany. We estimate the expected level of mortality as state-specific mortality trends and excess mortality in 2020 and 2021. We explore ecological statistical relationships between excess mortality, COVID-19 morbidity, and selected regional socioeconomic indicators using fixed-effects regression models. Our study shows that during the first pandemic year, there was South-to-North gradient in excess mortality in Germany, with excess mortality being higher in the South. Over the course of the second pandemic year 2021, this gradient changed to become an East-to-West gradient, with excess mortality being higher in the East. The results of the study show stronger effects of COVID-19 morbidity on excess mortality in East Germany. State-level indicators reflecting economic activity, employment, and capacity of intensive care units show significant correlations with excess mortality across the states. The results show pronounced state-level differences in the magnitude of excess mortality during the COVID-19 pandemic in Germany. Economic activity, employment and capacity of intensive care units were the most important state-level characteristics associated with the observed spatial variations in excess mortality.

Enhanced low-threshold motor unit capacity during endurance tasks in patients with spinal muscular atrophy using pyridostigmine

ObjectiveTo investigate the electrophysiological basis of pyridostigmine enhancement of endurance performance documented earlier in patients with spinal muscular atrophy (SMA). MethodsWe recorded surface electromyography (sEMG) in four upper extremity muscles of 31 patients with SMA types 2 and 3 performing endurance shuttle tests (EST) and maximal voluntary contraction (MVC) measurements during a randomized, double blind, cross-over, phase II trial. Linear mixed effect models (LMM) were used to assess the effect of pyridostigmine on (i) time courses of median frequencies and of root mean square (RMS) amplitudes of sEMG signals and (ii) maximal RMS amplitudes during MVC measurements. These sEMG changes over time indicate levels of peripheral muscle fatigue and recruitment of new motor units, respectively. ResultsIn comparison to a placebo, patients with SMA using pyridostigmine had fourfold smaller decreases in frequency and twofold smaller increases in amplitudes of sEMG signals in some muscles, recorded during ESTs (p < 0.05). We found no effect of pyridostigmine on MVC RMS amplitudes. ConclusionssEMG parameters indicate enhanced low-threshold (LT) motor unit (MU) function in upper-extremity muscles of patients with SMA treated with pyridostigmine. This may underlie their improved endurance. SignificanceOur results suggest that enhancing LT MU function may constitute a therapeutic strategy to reduce fatigability in patients with SMA.

Behaviour of concrete building units incorporating waste plastic eco-aggregate (RESIN8) subjected to fire conditions

Plastic waste has started to be incorporated within construction systems with potential benefits including improved sustainability, decreased costs, lighter construction units and enhanced thermal performance. However, the addition of plastics has an unknown impact on the fire response and associated behaviour of recycled construction products. Hence, this work seeks to answer the question: does the incorporation of waste plastic in masonry systems influence fire risk? This study investigates the effect of using the RESIN8 eco-aggregate in bricks, an aggregate based on processed waste plastic. This is done by exposing concrete bricks containing 0%, 5%, 10%, 20%, 30%, 40% and 50% RESIN8 by volume to a heat flux of 30 kW/m2 for an hour. The replacement content of the RESIN8 samples influenced both smoke production and mass loss rates, with high volumes of smoke observed for the highest replacement content of RESIN8. The capacity of the RESIN8 brick units was also found to drop by up to 34.7% of the original compressive strength. It is shown that low replacement rates (e.g. 5 and 10%) are unlikely to affect fire risk significantly, but higher replacement rates may be a concern due to smoke production and heat release rates.

Development status evaluation and path analysis of regional clean energy power generation in China

Due to differences in resource endowments, levels of economic development, energy structure, and effects of policy implementation, the level of clean energy development in different regions in China is nonuniform. To achieve carbon peaking and carbon neutrality, it is necessary to clarify the law of clean energy development and formulate policies tailored to local conditions. Based on relevant data on clean energy power, this paper establishes a system for evaluating the levels of clean energy development in each region in China by the entropy method and quantitatively analyzes the key factors influencing regional clean energy development. Based on this, the development characteristics of clean energy in different regions are discussed, and four historical paths for developing clean energy are summarized. The findings reveal the following: (1) overall, clean energy development in most regions in China is proceeding at a satisfactory pace. The contribution of resource endowment to clean energy development is considerable in Southwest and Northwest China. (2) The paths involved in the regional development of clean energy can be categorized into rising, declining, stable, and fluctuating types. (3) Currently, clean energy development in China remains largely dependent on resource endowments and is restricted by the capacity of traditional large-scale energy generation units. (4) In the foreseeable future, a sound and effective trading mechanism for the clean energy market will play an important role in economically developed regions and promote a higher level of development and generation of clean energy.

Improving cardiovascular outcomes for patients with heart failure in sub-Saharan Africa: conference proceedings of the 2022 Nigerian Cardiovascular Symposium.

The Nigerian Cardiovascular Symposium is an annual conference held in partnership with cardiologists in Nigeria and the diaspora to provide updates in cardiovascular medicine and cardiothoracic surgery with the aim of optimising cardiovascular care for the Nigerian population. This virtual conference (due to the COVID-19 pandemic) has created an opportunity for effective capacity building of the Nigerian cardiology workforce. The objective of the conference was for experts to provide updates on current trends, clinical trials and innovations in heart failure, selected cardiomyopathies such as hypertrophic cardiomyopathy and cardiac amyloidosis, pulmonary hypertension, cardiogenic shock, left ventricular assist devices and heart transplantation. Furthermore, the conference aimed to equip the Nigerian cardiovascular workforce with skills and knowledge to optimise the delivery of effective cardiovascular care, with the hope of curbing 'medical tourism' and the current 'brain drain' in Nigeria. Challenges to optimal cardiovascular care in Nigeria include workforce shortage, limited capacity of intensive care units, and availability of medications. This partnership represents a key first step in addressing these challenges. Future action items include enhanced collaboration between cardiologists in Nigeria and the diaspora, advancing participation and enrollment of African patients in global heart failure clinical trials, and the urgent need to develop heart failure clinical practice guidelines for Nigerian patients.

Technoeconomic analysis of a fungal pretreatment-based cellulosic ethanol production

Cellulosic biomass shows great potential as feedstock for bioethanol production. Despite clear benefits in terms of greenhouse gas mitigation and bioproduct potential, the commercial production of cellulosic ethanol remains economically challenging at the current state of technology. This paper presents a technoeconomic analysis of a fungal pretreatment-based cellulosic ethanol plant with a processing capacity of 2000 tonnes of switchgrass per day. The production process model was designed and simulated using SuperPro Designer. The plant's ethanol yield, capital investment per unit capacity, and unit ethanol production cost were estimated to be 211.90 L/t of switchgrass, $ 3.60/L, and $ 1.44/L of ethanol, respectively. Fungal pretreatment was the major contributor (72%) to the total capital investment, mainly due to the large quantity of equipment required in the process. A positive net present value (NPV) was generated for the baseline model at ethanol selling price of $ 1.50/L, which increased by 5-fold for 80% glucose yield. Glucose yield was the most sensitive to NPV for all the process parameters evaluated.

A Multi-Scale method for combined design and dispatch optimization of nuclear hybrid energy systems including storage

Reliable, carbon-free power generation is increasing in importance. Nuclear-renewable hybrid energy systems (NHES) are a potential solution for current generation challenges, but design and dispatch optimization for these systems remains challenging particularly when stochastic effects, long time horizons and nonlinear modeling are needed. This work presents a multi-scale method for combining the design and dispatch optimization problems for nonlinear NHES over long time horizons. Rather than treating the entire horizon as a single optimization problem, a large number of combined optimization problems are solved for shorter samples of the horizon resulting in distributions of optimal capacities for each of the capacities being optimized. The distributions are then aggregated, and the techno-economics of each aggregate is analyzed. The result is a contextual knowledge about the techno-economic tradeoffs for the system rather than a single set of optimal capacities. This method is applied to two NHES of varying complexity. Results indicate that unit capacities for a grid-connected district energy system can be reduced by at least 18.9% by allowing for 3 periods of power import over the course of a 2000 day dispatch. The algorithm is used to solve combined optimization problems with dispatch horizons 112.5 times longer than are solvable directly.

Educational Process as Something Dynamic

If we conceive the educational process as something dynamic, which basically combines what is given with what is emerging, we will understand that there are protagonists in it who have a fundamental role in this process, or perhaps we should say that, in this process, each and every one of the agents has a leading role. So, talking about curriculum implies that the subject can be approached from different perspectives, some more legitimate than others, some broader than others and, what is even more notorious, some more dynamic than others. It is in these differences where the essence of the educational process is conjugated, namely, in the conception of the curriculum, so it is worth asking: What are the educational units understanding by "development of their own curricular projects"? What are they actually doing? What curricular decisions do they make? Not only these questions arise, but many more, not to mention that it is also legitimate to doubt the capacity and preparation of teachers and educational units to undertake a process of conscious and responsible construction of an effective curriculum. It is interesting to approach the subject critically, not to reconsider the theoretical aspects, in which we find a wide range of postulates, but rather to revitalize the pedagogical practice in the place where it actually occurs, the classroom, and from there to enable discussion. and analysis of the problem, assuming that a paradigm change is urgent at all levels, otherwise, the entire society will suffer even more marked dehumanization. There are many challenges and requirements that fall on the educational task, and there are many who express their opinion, judge and dare to formulate lapidary sentences on the subject of education, with no more foundation than that allowed by a fragmented look at reality, therefore Therefore, a deeper look can shed light on why it has not yet been possible to reach a more optimal level in the quality indices, nor has equity been achieved, and what is worse, it seems that all that has been said is slipping away. through the window of the classrooms to end up in the realm of abstraction, from which it will not be possible to bring what is real and everyday. Thus, this work will also be a proposal for educational agents, a proposal that should not be kept together with others, but rather, hand in hand with the contingent, could give way to a better understanding of the problem.

A State-of-The-Art Technical Review on Chemically Enhanced Primary Treatment Plant

This review paper aims to provide a comprehensive assessment of chemically enhanced primary treatment (CEPT) processes in wastewater treatment plants (WWTPs). The outdated and ineffective performance of existing treatment plants has raised concerns regarding public health and environmental safety. CEPT has emerged as a promising alternative approach to enhance the efficiency and effectiveness of primary treatment. By adding chemical coagulants or precipitants to the wastewater, CEPT facilitates the aggregation and settling of suspended solids and contaminants, leading to improved treatment outcomes. This review evaluates the performance and effectiveness of different chemical coagulants, including ferric chloride (FeCl3), polyaluminum chloride (PACl), and alum, in terms of their ability to remove various pollutants such as suspended solids, turbidity, organic matter, nutrients, and emerging contaminants.&#x0D; The findings from the reviewed studies indicate that different coagulants exhibit varying efficiencies in removing specific parameters such as turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and phosphorous. Alum, ferric chloride, and ferric sulfate showed effectiveness in tannery wastewater treatment, while PACl maximized the removal of macro pollutants. The use of organic carbon sources and sludge recycling demonstrated cost reductions and improved nutrient removal. CEPT was found to be effective in TSS and BOD removal, potentially allowing for compact treatment facilities and enhancing the capacity of biological treatment units. The utilization of recovered alum from water treatment sludge (WTS) in CEPT showed comparable efficiencies to fresh alum. The paper also identifies research gaps and future directions in the field of chemically enhanced primary treatment, while discussing the challenges and limitations associated with CEPT processes. While the reviewed studies provide valuable insights into the performance of different coagulants and coagulant aids, further research is necessary to assess their long-term effects and cost-effectiveness in large-scale applications. The optimal choice of coagulant depends on specific wastewater characteristics and treatment goals. Understanding and optimizing CEPT processes will contribute to the development of innovative solutions for challenges in wastewater treatment systems caused by urbanization, population growth, and emerging contaminants in the major city like Kathmandu.

New product demand forecasting and production capacity adjustment strategies: Within-product and cross-product word-of-mouth

Manufacturers attach increasing importance to consumer word-of-mouth (WOM) as it assists them to improve demand forecasting and determine production capacity adjustment strategies. Communication among potential consumers occurs as a result of within-product and cross-product word-of-mouth. Within-product WOM has received due academic attention touching upon production volume adjustment under infinite capacity, while the impact of cross-product WOM on demand is under-researched with limited number of studies investigating production capacity adjustment. To address this research gap, we employ Agent-based Modeling and Simulation (ABMS) approach and the Bass model, together with considering within-product WOM and cross-product WOM, to modify previous demand forecasting methods and propose production capacity adjustment strategies. Results show: (1) higher performances delivered by manufactures depends more on production capacity adjustment strategies rather than production volume adjustment strategies; (2) production capacity adjustment strategies are closely associated with factors including unit capacity fixed cost and cross-product WOM; (3) on condition of low unit capacity fixed cost, proactive strategy leads to maximal expected net present value (NPV) of profit and minimal lost customer number (LCN); (4) greater within-product WOM and cross-product WOM might not as beneficial as expected, in that expanding within-product WOM and cross-product WOM in most cases leads to growing lost customer number.

REVIEW OF CONFIGURATIONS AND STRATEGIES OF CONTROL OF MICRONETWORKS BASED ON POWER ELECTRONICS

The growing implementation of distributed energy resources requires the development of the architecture of traditional electricity systems. With the growing deployment of distributed energy resources, especially for small combined heat and power plants and renewable energy sources based on distributed generation units, the architecture of the future power supply system must be transformed in order to carry out more complex operations. The article provides an overview of micronetwork configurations with greater flexibility and reliability, parameters, structures, and control methods for electronically connected distributed energy resource installations. Of the configurations considered, DC micronetwork and high-frequency AC micronetwork have shown better performance for some special applications, such as low-voltage and geographically small networks. The corresponding parameters in the structures of the blocks of distribution energy resources and the topology of power electronics are considered. With the increase in the nominal capacity of distribution power resource units, multilevel converters provide effective ways to reduce cost and increase efficiency. Methods of controlling electronically connected aggregates of distribution energy resources under different operating modes are described. Under the influence of load and line impedance characteristics, different strategies of load distribution among units of distribution energy resources, control of instantaneous active and reactive power are compared. A multi-level hierarchical control architecture, micronetwork power and energy management is described. A comparison of control architectures based on centralized and distributed technology indicates that the modern micronetwork must become smart and flexible with the help of telecommunication infrastructures and the next generation of information technology.

Forecasting coal power plant retirement ages and lock-in with random forest regression

Averting dangerous climate change requires expediting the retirement of coal-fired power plants (CFPPs). Given multiple barriers hampering this, here we forecast the future retirement ages of the world's CFPPs. We use supervised machine learning to first learn from the past, determining the factors that influenced historical retirements. We then apply our model to a dataset of 6,541 operating or under-construction units in 66 countries. Based on results, we also forecast associated carbon emissions and the degree to which countries are locked in to coal power. Contrasting with the historical average of roughly 40 years over 2010-2021, our model forecasts earlier retirement for 63% of current CFPP units. This results in 38% less emissions than if assuming historical retirement trends. However, the lock-in index forecasts considerable difficulties to retire CFPPs early in countries with high dependence on coal power, a large capacity or number of units, and young plant ages.

Implication of the diagenetic evolution, litho- and microfacies types on the storage capacity of the carbonate rocks in West Esh El Mallaha area, SW onshore Gulf of Suez, Egypt

The present study shed the light on the main litho- and microfacies of the Upper Cretaceous- Miocene sequence exposed at West Esh El Mallaha area (Egypt) with more focus on the carbonate rocks. Delineating the implication of the recorded facies and the diagenetic processes on the storage capacity of the entire sequence is among the prime targets of this study. The studied Esh El Mallaha sequence includes the Nubia, Duwi, Dakhla, Tarawan, Esna, Thebes, Abu Gerfan, Gharamul and Gemsa Formations, from older to younger respectively. The carbonate rocks exposed in the studied sequence were deposited in shallow marine, lagoonal outer ramp and environments with high energy and/or open marine conditions. These depositional environments are represented by ten microfacies types: lime-mudstone, foraminiferal wackestone, bioclastic wackestone, algal wackestone/packstone, foraminiferal packstone, bioclastic packstone/grainstone, phosphatic packstone/grainstone, oolitic and bioclastic grainstone, oyster rudstone and bafflestone. Aggrading neomorphism, calcite cementation (drusy calcite, pseudosparite, and poikilotopic calcite), silicification (silica cementation in the form of amorphous silica, micro-quartz, chalcedony and spherulitic quartz), compaction, clay mineral alteration, dissolution, fracturing and dolomitization are the main diagenetic processes recorded in the studied section.The storage capacity of the different rock units were primarily obliterated by multi-cementation phases by calcite, silica and/or clay minerals. Nonetheless, fracturing, dissolution and dolomitization enhanced the storage capacity and can be considered the main storage capacity-enhancing features in the studied sequence. These diagenetic features are more abundant in the studied Duwi, Thebes, Abu Gerfan and Gharamul Formations. This achievement indicates that the studied Upper Cretaceous- Miocene carbonate sequence may be promising in its subsurface extensions in the Gulf of Suez and other analogues in Egypt.

Design and operation of park-level integrated energy systems in various climate zones in China

Park-level integrated energy systems (PIESs) have a unique role in developing communities' energy infrastructure in more economical and sustainable ways. The design and operation of a PIES depend on the energy demand of buildings, which could be significantly affected by climate change. This paper presented the PIES in China's different climate zones (Harbin, Dalian, Changsha, and Haikou). The PIES integrating natural gas, solar and geothermal energy simultaneously produces electric, heating and cooling loads. A two-stage optimal approach was proposed in this paper to model the PIES mathematically. In the first stage, the worst-case scenario was obtained by the confidence interval combination method to optimize the minimum total cost. In the second stage, the operation strategies of following electric loads and following thermal loads were used to optimize the operation cost. The results revealed that the annual total cost of the PIES presented a v–shaped cost curve with the power generation unit (PGU) capacity from 400 kW to 2000 kW. PIES-1, located in Dalian, had the lowest total cost of $0.71 million. The carbon dioxide emissions had the same trend. When the PGU's capacity reached the optimum (1000 kW), the PGU's utilization rate was between 50% and 60% in all scenarios. From Harbin to Haikou, the operation cost gap between PIES-1 and PIES-2 narrowed from $0.18 million to $0.01 million. Moreover, PIES-1, located in Harbin, had the lowest CO2 emissions.

Assessment of the torsional behaviour of hollow core slabs

There are many applications in buildings in which precast pre-stressed hollow-core (HC) slabs are subjected to shear, torsion, or combined shear and torsion. Nonetheless, extruded HC units contain no transverse reinforcement, being inherently vulnerable to brittle failure modes due to shear and torsional actions. In previous work by the authors, a finite element (FE) modelling approach for HC units failing in shear was developed and validated against experimental test data. This paper aims to extend the applicability of the proposed FE approach to help improve the understanding of the torsional behavior of HC units. For this purpose, the developed model is further validated against experimental data available in the literature and then used to predict the torsional capacity of New Zealand-specific 200 mm deep HC units. Results suggest that the FE model is capable of predicting the capacity of HC slabs with and without eccentricity of the applied vertical load. Finally, the numerical results are used to evaluate the performance of available simplified analysis approaches for assessing the torsional capacity of HC units, which are found to be non-conservative if used with expected material properties.

Capability evaluation of a large regional clinical trials unit to assess growth over time.

e13671 Background: Participation in clinical trials is associated with better health outcomes, however prevalence of clinical trial participation among regional and rural patients are low, while simultaneously experiencing poorer health outcomes. Expanding capacity for clinical trials in regional locations increases accessibility for patients who live more remotely. The aim of this study is to describe the growth of a regional Australian clinical trials unit between 2014 and 2022, as part of a validation study of a recently published capability framework. Methods: Survey of Grampians Health Ballarat Clinical Trials unit across 2014 - 2022 was evaluated using a capability framework by Woollett et al. (2023) The framework uses a maturity model which allows a clinical trials unit capacity to be assessed by assigning a score (0-4) across several domains including trial infrastructure, leadership and culture, technology, skilled people, professional networks and collaborations and organisational support. A survey of the Grampians Health Ballarat Clinical Trials Unit was conducted to assign a score for each domain, and the average sum of scores used for an overall assessment; formative (0), developing (1), established (2), high performing (3), leading (4). The number of Principal Investigators (PI), opened trials and new participants recruited annually between 2014 – 2022 was obtained. Scatter plots, pairwise correlation and Bland Altman adjusted for trend were computed to show correlation and agreement between framework and number of PI and new trials opened per year. Results: Across all domains, Grampians Health Ballarat Clinical Trials unit was assessed as ‘established’ (average score 2.6) in 2014, compared to 2022 where the trials unit was considered ‘high performing’ (average score 3.4). Between 2014 and 2022 there was a tenfold increase in new patients recruited annually, n=8 and n=81, respectively. The only trial open in 2014 was investigator initiated, whereas in 2022 67% of trials were industry-sponsored trials. Oncology trials made up 82% of trials conducted, followed by gastroenterology (7%), cardiology (5%), infectious diseases (4%) and neurology (1%). investigators. There was one PI in 2014 compared to 18 in 2022. The framework correlated well with number of PI’s each year (r(7)=0.9 p=0.002) and number of trials opened each year (r(7)=0.8 p=0.015). Bland Altman adjusted for trend found 22% (2/9) outside limits of agreement for overall framework score and number of PI per year and 0% outside limits of agreement for overall framework score and new trials opened per year. Conclusions: This research is among the first to use a framework for outer metropolitan and rural areas to assess clinical trials unit capacity. The framework score correlated well with objective clinical trials data. Understanding the growth of a regional site may provide insight for developing clinical trials capacity in regional and rural areas.