Computational Water, Energy, and Environmental Engineering

Journal Information
ISSN / EISSN : 2168-1562 / 2168-1570
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 124
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Latest articles in this journal

Andrea Fischer, Jones S. Silva, Alexandre Beluco
Computational Water, Energy, and Environmental Engineering, Volume 10, pp 1-17; doi:10.4236/cweee.2021.101001

Some types of renewable energy have been experiencing rapid evolution in recent decades, notably among the energies associated with the oceans, such as wave and current energies. The development of new energy conversion technologies for these two forms of energy has been offering a large number of equipment configurations and plant geometries for energy conversion. This process can be implemented aiming at the result of feasibility studies in places with energy potentials, establishing minimum feasibility limits to be reached. This work aims to contribute in this sense with a feasibility study of a system with ocean wave power plants and with socio-current power plants to be operated on the southern coast of Brazil. This study evaluates a hybrid system with contributions from energy supplies obtained from wave plants and current plants, connected to the grid and supplying the demand of the municipalities in the North Coast region of the State of Rio Grande do Sul, the southernmost state of Brazil. The study was carried out with simulations with the Homer Legacy software, with some adaptations for the simulation of ocean wave plants and ocean current plants. The results indicate that the ocean wave power plants were viable in the vast majority of simulated scenarios, while the ocean current power plants were viable in the scenarios with more intense average ocean current speeds and with more expensive energy acquired from the interconnected system.
Tawheed Mohammed Elheesin Shareef, Zhongming Ma, Juan Chen, Xiaoxia Niu
Computational Water, Energy, and Environmental Engineering, Volume 10, pp 18-35; doi:10.4236/cweee.2021.101002

Water scarcity is relative and variable concept that can occur at any level of supply and demand. It is also a social construct, which is linked to the intervention in the water cycle and changes over time as a result of natural hydrological change. It is more severe when water acts as a backbone in economic policies, planning and management methods. Water scarcity can be expected to increase with most forms of economic development, but, if properly identified, many of its causes can be expected and avoided or mitigated. However, the limited irrigation management is considered a very important issue in the agricultural scope. Therefore, in this study, the relationship between water, crop production, photosynthesis, crop transpiration, crop growth, crop yields and water use efficiency have been discussed under limited irrigation conditions. However, the crops have some ability to adapt and resist against limited irrigation. Hence, under high temperate conditions, this is a shortage of water and photosynthesis is decreased with a pore (stoma) restraining. At the same time, the evapotranspiration reaches to the utmost value and the water use efficiency rises because of optimal monitoring of leaf pore (stoma). Therefore, the modality which is the reduction of the risks and improving industrial control in incomplete irrigation are the chief constraints of providing irrigation water in the future, which leads to increased crop production and ultimately providing a provision of food security.
Eduarda Noriko Tokuda, Juliana De Toledo Viana, Guilherme Augusto Nascimento Amorim, Renan Dias, Sherington Bigotto
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 37-47; doi:10.4236/cweee.2020.93004

The use of non-renewable resources by the construction industry has several environmental consequences, contributing to excessive energy consumption and loss of materials. So, the construction sector is always in search of improvement and methods that innovate the existing techniques, aiming at the use of alternative and sustainable materials. Bamboo is a perennial plant with fast growth rate and low cost that has great physical and mechanical characteristics that assure its performance in the building environment. The use of beams with total or partial replacement of steel by bamboo has been well studied, due to the possibility of using the same design methods used in reinforced concrete beams, since the bamboo-reinforced beams meet the Bernoulli-Kirchoff bending theory. The objective of the work was to adapt a design procedure into an electronic spreadsheet for bamboo reinforced concrete beams subjected to four-point bending, with rectangular section, according to Brazilian Standard NBR 6118 (2014). The spreadsheet was tested based on other authors taking into consideration a steel double reinforcement. The resulting values were equivalents to those obtained by the authors, validating the efficiency of the worksheet. This methodology aims to optimize the design process of beams and enable the substitution of steel by bamboo, highlighting the validation, from the structural point of view, obtained by the authors.
Yuanfan Li
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 22-35; doi:10.4236/cweee.2020.92003

Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in the United States. These plants range in size from a few hundred gallons per day (GPD) to over 1.445 billion gallons (MGD) per day. Wastewater treatment facilities are designed and constructed or upgraded to reduce the amount and diversity of pollutants. This article gives a review of the current industrial wastewater treatment technology in recent years, including treatment principles, advantages and disadvantages of each method, and the corresponding applications. Also, this article reviewed two common biological technologies Anaerobic Ammonium Oxidation (ANAMMOX) and Anaerobic Membrane Bioreactor (ANMBR) technology, by assessing their advantages, disadvantages, and costs, and provides resources for further technical research. This article can serve as a guide for anyone seeking information on innovative and emerging industry wastewater treatment technologies.
Qingcai Liu, Xuechun Wan
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 87-100; doi:10.4236/cweee.2020.94007

In China, systemic techno-economic analysis for solar tracker has been absent. To fill the blank, by taking the economic analysis of solar tracker application as the research object and using the LCOE method widely used internationally, the techno-economic analysis model of solar tracker was established according to conditions in China. Influence factors on LCOE were analyzed by using the established model, and the relationship between each cost factor and the cost component of energy leveling of tracker was further studied. In addition, the calculation method of investment payback period based on energy leveling analysis was established, and the influence of various factors on investment payback period was revealed through an example calculation. The research results will help to measure the economy of tracker application more accurately and comprehensively, and promote the popularization and application of solar tracker. The economic analysis model of solar tracker application was established by using LCOE method. The influence factors and cost component of LCOE were analyzed with the model. The payback period of solar tracker investment was also analyzed based on LCOE method.
Kamrul Hasan Chowdury, Nurun Nahar, Ujjwal Kumar Deb
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 185-215; doi:10.4236/cweee.2020.94012

The growing demand for energy and the negative environmental impacts of fossil fuel use are triggering global searches for a renewable and eco-friendly alternative biofuel. Microalgae are considered as one of the most promising feedstocks for biofuel production, due to many advantages including cultivation in non-arable land and being able to grow in wastewater or seawater. That is why; microalgae-based biofuels are regarded as one of the best candidates to replace fossil fuels. There are two main types of microalgae cultivation systems: Open Raceway Ponds and Closed Photobioreactos (PBRs). Due to some limitations in Open Raceways, PBRs have become the most favorable choice for biofuel producers, even though it is costly. To make the process viable, the growth of microalgae for biofuel production should be cost-effective. One way to achieve this goal is to optimize the environmental factors that influence their growth during the cultivation stage to increase the accumulation of bio-compounds of fuel. Algal growth relies mostly on nutrients, CO2 concentration, pH and salinity, light intensity and quality, temperature and finally mixing, which directly affects all other factors. Thus, before designing PBR, a thorough study on these growth parameters is needed. In the present study, we reviewed and evaluated these growth influencing factors in an extensive way to optimize biofuel production.
R. De A. Conceição Marcos, F. F. De Mendonça Luis, A. D. Lentini Carlos, Marcos R. De A. Conceição, Luis F. F. De Mendonça, Carlos A. D. Lentini
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 75-85; doi:10.4236/cweee.2020.93006

Two additional features are particularly useful in pixelwise satellite data segmentation using neural networks: one results from local window averaging around each pixel (MWA) and another uses a standard deviation estimator (MWSD) instead of the average. While the former’s complexity has already been solved to a satisfying minimum, the latter did not. This article proposes a new algorithm that can substitute a naive MWSD, by making the complexity of the computational process fall from O(N2n2) to O(N2n), where N is a square input array side, and n is the moving window’s side length. The Numba python compiler was used to make python a competitive high-performance computing language in our optimizations. Our results show efficiency benchmars
Mohamed Msaddek, George Kimbowa, Abdelkader El Garouani
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 159-184; doi:10.4236/cweee.2020.94011

Human population growth and land-use changes raise demand and competition for water resources. The Upper OumErRabia River Basin is experiencing high rangeland and matorral conversion to irrigated agricultural land expansion. Given Morocco’s per capita water availability, River-basin hydrologic modelling could potentially bring together agricultural, water resources and conservation objectives. However, not everywhere have hydrological models considered events and continuous assessment of climatic data. In this study, HEC-HMS modelling approach is used to explore the event-based and continuous-process simulation of land-use and land cover change (LULCC) impact on water balance. The use of HEC-GeoHMS facilitated the digital data processing for coupling with the model. The basin’s physical characteristics and the hydro-climatic data helped to generate a geospatial database for HEC-HMS model. We analyzed baseline and future scenario changes for the 1980-2016 period using the SCS Curve-Number and the Soil Moisture Accounting (SMA) loss methods. SMA was coupled with the Hargreaves evapotranspiration method. Model calibration focused on reproducing observed basin runoff hydrograph. To evaluate the model performance for both calibration and validation, the Coefficient of determination (R2), Nash-Sutcliffe efficiency (NSE), Root Mean Square Error (RSR) and Percent Bias (PBIAS) criteria were exploited. The average calibration NSE values were 0.740 and 0.585 for event-based (daily) and continuous-process (annual) respectively. The R2, RSR and PBIAS values were 0.624, 0.634 and +16.7 respectively. This is rated as good performance besides the validation simulations were satisfactory for subsequent hydrologic analyses. We conclude that the basin’s hydrologic response to positive and negative LULCC scenarios is significant both positive and negative scenarios. The study findings provide useful information for key stakeholders/decision-makers in water resources.
Rajib Karmaker, Ujjwal Kumar Deb, Amrita Das
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 145-158; doi:10.4236/cweee.2020.94010

Nowadays presence of crack in different engineering structures becomes a serious threat to the performance. Since most of the civil and mechanical structures may be damaged due to material fatigue, mechanical vibration, environmental attack and long-term service. Moreover, dynamical systems of a beam usually possess a non-linear character, which causes practical difficulties on the model-based damage detection techniques. This paper presents a novel approach to detect damage in a simply supported beam. In this study, a numerical simulation using the Finite Element Method (FEM) has been done to determine the frequencies to detect the crack in a concrete beam of length 0.12 m and width 0.015 m. A vibration-based model is employed to simulate the results by using COMSOL Multiphysics. At the tip, by performing the computational analysis it is found that the presence of cracks affects the natural frequencies of the concrete structure. It is observed that after applying load, the frequencies of the cracked beam have been changed with the variation of the location of the crack for all the modes of vibration. It also found that maximum frequency reserved at the cracked point so it will also help us to detect different hidden defects in any structure. A comparison is also made with the experimental results. It is also found that the effect of crack is more near the fixed end than at the free end.
Leyrer Anna, Bush Edward, Geaghan James, Meyer Buffy, Anna Leyrer, Edward Bush, James Geaghan, Buffy Meyer
Computational Water, Energy, and Environmental Engineering, Volume 9, pp 13-21; doi:10.4236/cweee.2020.92002

Insects such as Acheta domesticus account for over half of marsh fish and migratory bird diet. Therefore, insects are very important to marsh and island ecosy stems and are susceptible to oil contamination, but little research has been done to study the effects of oil spills on cricket populations. The purpose of this experiment was to determine the effects of an oil spill event on Acheta domesticus mortality and hatch rate to establish environmental sustainability. The treatment groups included 0% oil contamination, 5% oil contamination and 10% oil contamination. The scientist counted the number of deaths in two-week, four-week, and six-week-old crickets after oil contamination. In addition, the scientist counted the number of hatchlings among treated cricket eggs. Error bar lines in the results section supported the scientist’s hypothesis that the crickets would be affected by oil contamination. In fact, over 90% of the 10% oil treatment group died and over 80% of the 5% oil treatment group died after five days of oil contamination in the six-week-old experiment. The scientist used a Gas Chromatography Mass Spectrometer to determine if benzene, toluene, ethylbenzene, or xylene (total) were present in the sediment samples. BTEX exposure is suspected to possibly cause insect mortality. These volatile organic compounds were present in the samples and were found in higher quantities in samples with higher concentrations of oil. The highest quantity of volatile organic compounds present was xylene. After studying the population dynamics of the tested Acheta domesticus, the scientist found that the two-week and four-week-old crickets’ survivability could fit a linear model while the six-week-old crickets fit an exponential model. The scientist used these models to observe how long it took each treatment group to approach zero, and the oiled groups grew closer to a population of zero significantly faster. For example, it took about twenty-seven days for the 10% treatment group’s population to approach zero whereas the control, 0% treatment group, took about seven days in the two-week-old cricket experiment. Overall, the six-week-old crickets had the highest mortality, and the cricket egg experiment resulted in extremely low hatch rate. Specifically, the highest number of crickets that hatched in an oiled replication either 5% or 10% oil was eight out of the five thousand eggs laid. Since the adult crickets are the most physically able to reproduce and the cricket eggs had low hatch rates, the cricket population would significantly decrease after an oil spill with 5% or more soil contamination. However, if the plant matter that crickets consume is still present in their environment, they may be able to recover.
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