maximum capacity
Recently Published Documents


TOTAL DOCUMENTS

366
(FIVE YEARS 107)

H-INDEX

23
(FIVE YEARS 3)

Author(s):  
Marina de P. Moura ◽  
Alfredo Ribeiro Neto ◽  
Fábio A. da Costa

ABSTRACT Reservoirs are the primary source of water supply in the semiarid region of Pernambuco state, Brazil, because of the constant water scarcity affecting this region. Knowledge of the amount of water available is essential for the effective management of water resources. The volume of water stored in the reservoirs is calculated using the depth-area-volume relationship. However, in most reservoirs in the semiarid region, this relationship is currently out of date. Therefore, the objective of this study was to explore the potential and limitations of the application of the ISODATA unsupervised classification method to calculate the depth-area-volume relationships of reservoirs in the semiarid region of Pernambuco, Brazil. The application of the ISODATA method was evaluated in three reservoirs in the state of Pernambuco, i.e., Poço da Cruz, Barra do Juá, and Jucazinho. The results were compared with the updated curves of reservoirs obtained from bathymetry and recent LiDAR surveys. The ISODATA method presented satisfactory results for the three reservoirs analyzed. The mean absolute error of the volume in Poço da Cruz and Barra do Juá was lower than 1% of the maximum capacity. The use of the ISODATA method meant that the surface area underestimation tendency in the Poço da Cruz reservoir was less than when spectral indices were used.


2021 ◽  
Vol 6 (12) ◽  
pp. 2172-2175
Author(s):  
Sudirman Sudirman ◽  
Hasan Basri

The Samarinda State Polytechnic has a hydrant that does not work, because the installation is damaged and is 35 years old. Currently, a simple fire fighting water installation has been made at three points with a length of 257 meters for 16 buildings, which utilizes lake water inside the Samarinda State Polytechnic campus. Therefore, this service activity is intended to provide skills for security guard in the Samarinda State Polytechnic regarding the use of hydrants. The specifications of the equipment used are portable centrifugal pumps with a maximum capacity of 700 liters/minute, a horizontal reach length of 40 meters, a vertical height of 12 meters and a pump pressure of ±5 bar. The results of this activity revealed that all security guard at the Samarinda State Polytechnic were able to operate a simple fire extinguisher installation. In addition, security personnel also have the ability to maintain a fire pump engine.


Author(s):  
Syukri Yunus ◽  
R.H. Sukma

The application of Photovoltaic (PV) is one solution to the increasing demand for electrical energy. However, the application of photovoltaic (PV) must be in the right location and capacity so that the power loss you want to reduce is large and the voltage profile is good. Photovoltaic (PV) generates DC voltage which is then required by an inverter to convert it to AC. The inverter is a non-linear load that produces harmonics. Harmonics in an electric power system can be known from Total Harmonic Distortion (THD). The purpose of this study is to determine the optimal location of placement (PV) and its maximum capacity so that the power loss is smaller. The resulting voltage and THD profile conform to the permitted standards. The methods used in determining the optimal location of photovoltaic (PV) are Loss Sensitivity Factor (LSF) and Voltage Sensitivity Index (VSI). ETAP 16 software is used for power and harmonic flow simulation. From this research, the most optimal photovoltaic (PV) placement is on bus 10 (bus 283 T) with a maximum capacity of 3255 kVA. This placement location provides minimal power loss and a good voltage profile taking into account the permitted standard THDv.


2021 ◽  
Vol 11 (24) ◽  
pp. 11909
Author(s):  
Wei Chen ◽  
Yijun Shi ◽  
Wei Wang ◽  
Wenjing Li ◽  
Chao Wu

As an important space for disaster prevention, the construction of emergency shelters is crucial for the creation of a complete disaster relief facility network. Based on the goal of the prevention of day and night disaster, short-term fixed shelters are taken as the study object of the present work, and models are designed for evacuation simulation and the spatial optimization of shelters. According to the simulation, 680 of the 2334 demand points were found to be incompletely evacuated, and the average time for everyone to be evacuated was 10.3 min. Moreover, of the 888 short-term fixed shelters, only 218 did not reach their maximum capacity. In the context of short-term fixed sheltering, Haizhu was found to have the largest number of non-evacuated people (1.11 million), and the average number of non-evacuated people in Yuexiu was the largest (2184). According to the spatial optimization data of the shelters, the numbers of target plots for new shelter resources that must be added in Haizhu, Yuexiu, Liwa, and Tianhe are 406, 164, 141, and 136, respectively, the effective shelter areas of which are 2,621,100, 2,175,300, 812,100, and 1,344,600 m2, respectively. A total of 487 short-term fixed shelters and 360 temporary shelters were newly added, and the recommended scales for Haizhu, Liwan, Tianhe, and Yuexiu were 243, 70, 58, and 116, respectively, with average effective areas of 6169 m2, 5577 m2, 8707 m2, and 12,931 m2, respectively. Additionally, the recommended scales of newly added temporary shelters in Haizhu, Liwan, Tianhe, and Yuexiu are 163, 71, 78, and 48, with an average effective area of 2706, 2581, 4017, and 6234 m2, respectively. These findings provide a direct quantitative basis for the spatial optimization of various types of emergency shelters, and the method proposed in this paper supports the planning and layout of emergency shelters, as well as the improvement of the efficiency of urban resource allocation.


2021 ◽  
Author(s):  
Ismail Mohamed Ahmed ◽  
Aly A. Helal ◽  
Rasha Gamal ◽  
Salah aboEinien ◽  
Abdullah A. Helal

Abstract Magnetite nanoparticles (Fe3O4) and humic acid coated magnetite nanoparticles (Fe3O4/HA) were investigated for the removal of U(VI) from aqueous solution. Batch sorption experiments were studied as a function contact time, adsorbent mass, U(VI) concentration and pH. The sorption kinetic data follow the pseudo-second order while the isotherms are found to obey Langmuir model with maximum capacity (Qmax) of 230, 196 mg/g for Fe3O4 and Fe3O4/HA, respectively. The study reveals that humic acid decreases the sorption capacity due to the formation of a polyanionic organic coating and thus altering the surface properties of the particles and reduces the magnetite aggregation and stabilizes the magnetite suspension.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dimitrios Dadakas

Abstract We examine trade flows for Arab nations concentrating on the Gulf Cooperation Council (GCC) and Pan-Arab Free Trade Area (PAFTA) areas, to identify opportunities to enhance intra-Arab trade and facilitate regional integration. We employ panel data for the years 2003–2017 and a structural gravity model together with an “aggregate” trade potential measure that treats the GCC and PAFTA areas as single countries. Results suggest that, by 2015, intra-area trade had reached maximum capacity for both blocs. Potential to trade also reached capacity with many of the largest Free Trade Areas around the world, however, opportunities for trade expansion that still exist with the MERCOSUR and ASEAN, as well as many distinct destinations, can assist in strategic planning to enhance integration efforts.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7302
Author(s):  
Dun-Xian Tan ◽  
Rüdiger Hardeland

In this article, we attempt to classify a potential dimorphism of melatonin production. Thus, a new concept of “reserve or maximum capacity of melatonin synthetic function” is introduced to explain the subtle dimorphism of melatonin production in mammals. Considering ASMT/ASMTL genes in the pseudoautosomal region of sex chromosomes with high prevalence of mutation in males, as well as the sex bias of the mitochondria in which melatonin is synthesized, we hypothesize the existence of a dimorphism in melatonin production to favor females, which are assumed to possess a higher reserve capacity for melatonin synthesis than males. Under physiological conditions, this subtle dimorphism is masked by the fact that cells or tissues only need baseline melatonin production, which can be accomplished without exploiting the full potential of melatonin’s synthetic capacity. This capacity is believed to exceed the already remarkable nocturnal increase as observed within the circadian cycle. However, during aging or under stressful conditions, the reserve capacity of melatonin’s synthetic function is required to be activated to produce sufficiently high levels of melatonin for protective purposes. Females seem to possess a higher reserve/maximum capacity for producing more melatonin than males. Thus, this dimorphism of melatonin production becomes manifest and detectable under these conditions. The biological significance of the reserve/maximum capacity of melatonin’s synthetic function is to improve the recovery rate of organisms from injury, to increase resistance to pathogen infection, and even to enhance their chances of survival by maximizing melatonin production under stressful conditions. The higher reserve/maximum capacity of melatonin synthesis in females may also contribute to the dimorphism in longevity, favoring females in mammals.


Author(s):  
Mariana Helou ◽  
Mahmoud El-Hussein ◽  
Kurtulus Aciksari ◽  
Flavio Salio ◽  
Francesco Della Corte ◽  
...  

Abstract A massive explosion have ripped Beirut on August 4, 2020, leaving behind more than 6000 casualties, 800 regular floor admissions, 130 intensive care unit admissions, and over 200 deaths. Buildings were destroyed, hospitals in Beirut were also destroyed, others became nonfunctional. A disaster code was initiated in all the hospitals. Victims were transported by the Lebanese Red Cross or by volunteers to the nearest hospital that was still functional. Hospitals were flooded in patients, the coordination between health care centers was missing. Each hospital was functioning to its maximum capacity. With the many challenges we had, a rapid response was initiated. An effective triage done outside the Emergency had the major role in saving lives. After the Beirut Explosion, an assessment of the disaster plan and a major evaluation of the hospitals’ coordination is needed.


Author(s):  
Kumar Cherukupalli ◽  
Vijaya Anand N

In this paper, the optimal distribution generation (DG) size and location for power flow analysis at the smart grid by hybrid method are proposed. The proposed hybrid method is the Interactive Autodidactic School (IAS) and the Most Valuable Player Algorithm (MVPA) and commonly named as IAS-MVPA method. The main aim of this work is to reduce line loss and total harmonic distortion (THD), similarly, to recover the voltage profile of system through the optimal location and size of the distributed generators and optimal rearrangement of network. Here, IAS-MVPA method is utilized as a rectification tool to get the maximum DG size and the maximal reconfiguration of network at environmental load variation. In case of failure, the IAS method is utilized for maximizing the DG location. The IAS chooses the line of maximal power loss as optimal location to place the DG based on the objective function. The fault violates the equality and inequality restrictions of the safe limit system. From the control parameters, the low voltage drift is improved using the MVPA method. The low-voltage deviation has been exploited for obtaining the maximum capacity of the DG. After that, the maximum capacity is used at maximum location that improves the power flow of the system. The proposed system is performed on MATLAB/Simulink platform, and the effectiveness is assessed by comparing it with various existing processes such as generic algorithm (GA), Cuttle fish algorithm (CFA), adaptive grasshopper optimization algorithm (AGOA) and artificial neural network (ANN).


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zhao Lijun ◽  
Li Qingsheng ◽  
Ding Guanhua

High growth of the population and developed industries, on the one hand, increased the demanded energy considerably. Growth of the fossil fuel-based power generation, on the other hand, has high environmental effects. Accordingly, renewable energy sources are mainly interested in the recent years as clean resources. These sources also can be economical cases in long term. Nevertheless, their intermittent feature is a main drawback. Integration of these resources with the rest of the grid can increase their advantages and tackle their main drawbacks. In the present work, a novel programming method is proposed for energy management and optimization of operational expenses over a grid-connected microgrid (MG). The considered MG contains various renewable resources. Some uncertainties should be considered in the integration of renewable resources with the grid, which can affect the system performance. Main uncertain parameters are studied in this paper such as predicted values for green power sources, maximum capacity for fuel cells (FCs), energy storage sources (ESSs), maximum capacity for transmission line, and also hourly loads, achieving a higher efficiency. This paper utilized fuzzy idea for presentation of mentioned uncertain parameters in the MG. Moreover, this work employed a 3-stage optimization algorithm for obtaining the best programming for the MG by considering the uncertain parameters. This paper also used a practical test system to validate the proposed method through minimizing the total cost. Additionally, a sensitivity analysis is performed to study the effects of oscillations of all components in the MG and their associated uncertainties over the obtained results.


Sign in / Sign up

Export Citation Format

Share Document