93 research outputs found

    Techno-economic assessment and optimization of a solar-assisted industrial post-combustion CO2 capture and utilization plant

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    This paper studies the techno-economic feasibility of the solar-assisted regeneration process of the largest industrial CO2 removal monoethanolamine-based plant in Iran. The plant incorporating parabolic troughs is modelled using System Advisor Model software and the weather data are derived from the European Commission''s Photovoltaic Geographical Information System. Sensitivity analyses are realized to evaluate the effect of important parameters, i.e., the solar multiple and the hours of storage, and to reveal the optimum case. The studied impacts are linked to the overall net energy generation and the levelized cost of heat (LCOH). The optimum case is found to have a solar multiple of 3.1 and 18-hours of storage, resulting in a solar share of 0.7 and a LCOH of 3.85 (¢/kWh). When compared to the base case (solar multiple of 2 and 6 h of storage), the optimum solution results in a similar LCOH but it achieves the generation of an additional 16, 112 MWhth annually. The thermal energy supplied by the solar system leads to an annual reduction in the natural gas consumption of approximately 3.8 million m3 that results in a CO2 emission reduction of 7.1 kton. © 2021 The Author

    Comprehensive thermodynamic and operational optimization of a solar-assisted LiBr/water absorption refrigeration system

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    Absorption cooling systems have been investigated for many years due to their ability to use low-grade heat instead of electricity as the energy source. The aim of this work is to advance the performance of a single-effect Lithium bromide/water absorption cooling system. Taking the generator and evaporator temperatures as variables, the system is optimized to maximize exergetic and energetic efficiencies at different operational conditions using a multi-objective–multi-variable Genetic Algorithm. The Group Method of Data Handling neural network approach is adopted to derive correlations between the design variables and operational parameters. Finally, the system is coupled to evacuated tube solar collectors and compared to a similar system. The results reflect a maximum improvement in energetic and exergetic efficiencies of about 9.1% and 3.0%, respectively. This translates into savings of 187 dollars for every square meter of solar collector at present time. This improvement is achieved by decreasing the mean temperature of the generator by 6.2 °C and increasing the mean temperature of the evaporator by 1.6 °C. In the case of applying low-grade heat such as solar energy, it brings about both an improvement in the thermodynamic performances and a reduction in the generator temperature

    Modeling sustainability : Population, inequality, consumption, and bidirectional coupling of the Earth and human systems

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    Over the last two centuries, the impact of the Human System has grown dramatically, becoming strongly dominant within the Earth System in many different ways. Consumption, inequality, and population have increased extremely fast, especially since about 1950, threatening to overwhelm the many critical functions and ecosystems of the Earth System. Changes in the Earth System, in turn, have important feedback effects on the Human System, with costly and potentially serious consequences. However, current models do not incorporate these critical feedbacks. We argue that in order to understand the dynamics of either system, Earth SystemModels must be coupled with Human SystemModels through bidirectional couplings representing the positive, negative, and delayed feedbacks that exist in the real systems. In particular, key Human System variables, such as demographics, inequality, economic growth, and migration, are not coupled with the Earth System but are instead driven by exogenous estimates, such as United Nations population projections.This makes current models likely to miss important feedbacks in the real Earth-Human system, especially those that may result in unexpected or counterintuitive outcomes, and thus requiring different policy interventions from current models.The importance and imminence of sustainability challenges, the dominant role of the Human System in the Earth System, and the essential roles the Earth System plays for the Human System, all call for collaboration of natural scientists, social scientists, and engineers in multidisciplinary research and modeling to develop coupled Earth-Human system models for devising effective science-based policies and measures to benefit current and future generations

    PHYSICAL SPATIAL DEVELOPMENT: A GIS ANALYSIS WITH EMPHASIS ON ENVIRONMENTAL IMPACTS-CASE STUDY NALOS CITY, IRAN

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    Unplanned urban developments have led to changes in uncontrollable urban spatial structure. For this reasons, informed guidance, principle organization and spatial planning are necessary for urban sprawl and development. In this research, different forms of urban development were considered and development basic barriers including rivers, topography, geology, ecological conditions, facilities andindustries were determined and the role of each one was surveyed. Development trends that are based on effective parameters especially environmental impacts were modeled with Geographic Information Systems. The quality of urban planning and management can be upgraded when available and valid data are handled in an advanced manner with the aid of Geographic Information Systems. The innovative technology can support planning and decision making by offering relatively quick response on analytical questions and monitoring issues. Experienced expert determined the degree and primacy of urban sprawl and development parameters generally and for nalos case study, these parameters and criteria and their weights were marked, then were modeled with Geographic Information Systems for nalos developments. With using GIS and it capabilities in calculation of land size forecasting for Nalos development and its positioning we could take a step in planning directions such as sustainable development achievements

    Surface-waves suppression using seismic interferometry for imaging and monitoring of the Groningen subsurface

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    High-resolution seismic reflections are essential for imaging and monitoring applications using data-driven methods such as seismic interferometry (SI) and Marchenko redatuming. For seismic land surveys using sources and receivers at the surface, the surface waves are the dominant noises that mask the reflections. We use SI to suppress surface waves from the reflection dataset. SI is a technique that allows the retrieval of new seismic responses at one receiver from a virtual source at the position of another receiver using, e.g., cross-correlation or convolution. We processed a two-dimensional seismic reflection dataset acquired along a line in Scheemda, located in the Groningen province of the Netherlands. The sources are placed with a spacing of 2 m, and 601 receivers are placed every 1 m. We implemented some pre-processing steps, including source signature deconvolution and filtering. Then, we applied SI by cross-correlation by turning receivers into virtual sources to estimate the dominant surface waves. Afterwards, we performed adaptive subtraction with different filter parameters for the matching filter to minimise the difference between the surface waves in the original data and the result of SI. Comparing the retrieved results from SI with the original data in the time domain and the frequency-wavenumber domain shows that at least some parts of surface waves are suppressed from the dataset, which can help to better visualise reflections for future studies in imaging and monitoring the subsurface.Applied Geophysics and Petrophysic

    Monitoring changes inside subsurface layers using non-physical reflections retrieved from seismic interferometry

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    Seismic interferometry (SI) is a principle for retrieving responses between two receivers using cross-correlation. After the retrieval, one of the receivers acts as a virtual seismic source whose response is retrieved at the second receiver. Correct response retrieval relies on assumptions, among other, of a lossless medium being illuminated homogeneously by sufficiently densely spaced sources (passive or active). When these assumptions are not met, non-physical reflections might appear in the results of SI due to insufficient destructive interference. These non-physical reflections are caused by internal reflections inside subsurface layers. However, the non-physical reflections could be used for monitoring changes in the subsurface layers that generate them. We investigate utilization of non-physical reflections for monitoring velocity changes for purposes of the DeepNL programme. We simulate reflection experiments using an acoustic finite-difference modelling for a horizontally layered model and for a subsurface with inclined layers. We perform SI by autocorrelation and by cross-correlation. Comparing retrieved results with the directly modelled results, we confirm previous results that for a layered subsurface the retrieved ghost reflections can be used for multiple offsets. For inclined layers, zero-offset ghost reflections can be retrieved for the different receiver locations. Both types of non-physical reflections are sensitive to velocity change and thickness of the layer that cause them to appear in the SI results, so they can be used for monitoring purposes of the subsurface.Accepted Author ManuscriptApplied Geophysics and Petrophysic

    Improving Growth and Fruit Yield of Watermelon Using Mycorrhizal Fungi and Salicylic Acid under Different Irrigation Regimes

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    Water scarcity is the main natural limitation for agricultural production in arid and semi-arid regions. The aim of this study was to investigate the effect of mycorrhizal fungi and salicylic acid on yield and quality of watermelon under water stress. For this purpose, a split factorial experiment was conducted with three replications based on a randomized complete block design in two years. Irrigation treatment at three levels of receiving 100%, 80% and 60% of water requirement were placed as the main factor in the main plots. Mycorrhizal fungus in two levels (including no inoculation and soil inoculation by 20 g m-2) along with spraying of salicylic acid in three levels (including 0, 50 and 100 mg L-1) were designated to the subplots. The highest amounts of proline concentration, peroxidase and catalase enzymes activities were recorded in 60% irrigation treatment. Electrolyte leakage decreased by salicylic acid application, though in each irrigation treatment the lowest electrolyte leakage was recorded in 100 mg L-1 treatment of salicylic acid. Electrolyte leakage was significantly reduced by mycorrhizal fungi application. The highest (9.12%) and the lowest (8.08%) level of total soluble solids were recorded respectively in 80% and 100% irrigation treatments. The highest amount of TSS (9.07%) was obtained with mycorrhizal fungi. TSS was significantly increased by 6.70% and 11.20% with 50 and 100 mg L-1 salicylic acid treatments, respectively, compared to the control. The lowest fruit yield (34.76 t ha-1) was obtained when the plants were exposed to 60% irrigation treatment and no mycorrhizal fungus inoculation conditions. Fruit yield increased significantly in the presence of mycorrhizal fungi inoculation across all irrigation treatment levels, with the highest fruit yield (68.82 t ha-1) being obtained when plants were grown under 100% irrigation treatment and mycorrhizal fungi inoculation conditions. It may be concluded that using mycorrhizal fungus as a biofertilizer and salicylic acid as a plant growth regulator can reduce the harmful effects of drought stress and, hence, it can be recommended to increase the fruit yield and quality of watermelon at least in arid-semiarid conditions
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