Comparison Study of Cascaded Organic Rankine Cycles with Single and Dual Working Fluids for Waste Heat Recovery

This study compares thermodynamics, economics, and environmental performance of cascaded ORCs operated under a single and dual fluids. In the single fluid cascaded ORC, toluene, benzene, acetone and cyclopentane are run in high and low temperature cycles, whereas in dual fluid cascaded ORC, toluene, benzene, acetone and cyclopentane are run in high temperature cycle and R601a in the low temperature cycle. The analysis compares variations in expander inlet temperature and condensation temperature. Thermodynamic performance involved net power output (Pnet) and thermal efficiency (ηth), while economic indicators included net present value (NPV) and levelized cost of electricity (LCOE). In environmental performance, the annual reduction in carbon dioxide emission (CO2-eq) is assessed. The findings revealed that dual fluid cascaded ORC generated the highest Pnet of 1245.11 kW while single fluid cascaded ORC reached 1170.27 kW. The dual fluid cascaded ORC showed the significant increase in Pnet (%DPnet) for about 43% at the lowest expander inlet temperature (500 K). In terms of ηth, dual fluid cascaded ORC attained 37.23 % while single fluid cascaded ORC reached 33.25%. It is further found that acetone+R601a performed well in dual fluid cascaded ORC, resulting in the highest Pnet and allowing system’s NPV to turn positive sooner than other fluids. Furthermore, cyclopentane+R601a had the lowest LCOE of 0.0158 US$/kWh, which is 1.1% lower compared to the single fluid cascaded ORC and competitive in the Thai electricity market. In environmental saving, dual fluid cascaded ORC reduced about 144.96 tCO2-eq/year, and outperformed single fluid cascaded ORC by roughly 6.39%

Application Research of an Automatic Control Seawater Reverse Osmosis (SWRO) System Based on the Siemens PLC

To solve the global environmental problem of a shortage of freshwater resources, seawater desalination is considered one of the most promising solutions. In this research, the main novelty of the seawater desalination system lies in its utilization of a reverse osmosis unit as the core process for producing drinking water. By optimizing the pretreatment section in the process flow, a seawater reverse osmosis (SWRO) control system based on Siemens PLC with a high degree of automation was developed, which has the advantages of convenient maintenance and monitoring. In addition, through research on reverse osmosis systems, the results showed that within two years of operation, the total desalination rates of the primary and secondary reverse osmosis systems were not less than 99% and 97.5%, respectively. Furthermore, the water quality after desalination was tested. When the doses of CaCl2, MgCl2 and NaHCO3 were 20 mg/L, 15 mg/L, and 50 mg/L, respectively, high-quality drinking water was obtained. Finally, a reasonable process plan and corresponding estimates were given for the complex water source conditions. Compared with traditional seawater desalination systems, our system has the advantages of easy operation, efficient water production and lower price. Accordingly, this study will help to solve drinking-water problems in some freshwater-scarce regions

Antisolvent Crystallization (ASC) in Aqueous System: Fundamentals, Sustainability Aspects, and Applications

The present perspective focuses on fundamental and applied attributes of antisolvent crystallization (ASC) in aqueous systems and establishes its potential for various industrial applications. In the ASC method, supersaturation is attained by adding a secondary solvent (antisolvent) to a solution leading to the crystallization of the solute. ASC offers the advantages of increasing yields, and conserving energy over the conventional evaporative or cooling crystallization, and thus appears to be a growing industrially important and sustainable process. The insights on the role of phase equilibrium thermodynamics and kinetics in controlling the crystallization process and crystal properties during ASC are discussed. The choice of solvents is a critical factor in ASC, and the solvent type, properties, and selection are considered briefly. The evaluation of the sustainability aspect of ASC by assessing the environmental benignity of solvents, the impact of their life cycles on the ecology, and associated economic costs are presented. A comprehensive list of solvents used for ASC and their usage pattern is also included. Successively reintegrating ASC into process design and developing different process configurations (stand-alone and hybrid) are reviewed. Finally, the paper highlights the opportunity for more widespread application of ASC in the fields of salt extraction, water treatment, hydrometallurgy, bioprocessing, and the pharmaceutical industry

An Assessment Tool for Energy Audit of Buildings in Jordan Using Simulation

  In developed nations, there's a growing concern for sustainable energy management, particularly regarding enhancing energy efficiency in both existing and new buildings. The methodology presented considers the energy modelling and simulation of manufacturing buildings through thermal and electrical loads calculations using Dymola/Modelica software. The thermal model is built with the primary components of Dymola along with available models to calculate the heating and cooling loads, whereas the electrical model was calculated using consumption patterns, then the total model was validated against real measurements where the error percentage was 9.96 %. The yearly heating load baseline was 6295 kWh/y and for cooling 46276 kWh/y., the exciting potential for energy- savings and load flexibility, and some suggestions for improving consumption were pointed out and identified. It found that the highest influence on the thermal load reduction was using the double glaze with shading with 61% of the energy-saving options, then replacing the fluorescent with LED with 30%, and finally, the roof insulation was the least influence with 9.5%. For the total consumption, the highest percentage was for replacing the fluorescent with LED with 78% of energy-saving options, then double glaze with shading, and finally the lowest is for the roof insulation

Performance of the Petroleum Reservoir Under Waterflooding at the Petrochad Field in Mangara-Chad

The Mangara petroleum field is made up of three superimposed reservoirs (C, D, E) with approximately 2500 m depth. These are unconsolidated sandstone reservoirs with an underlying active aquifer. The petrophysical properties of the reservoirs are relatively good as it’s a self-sourced unconventional reservoir based on its organic richness characteristics unconventional resource opportunity as tight carbonate reservoir. Tank pressure is approximately 2900 psi, for an average temperature of 180°F. Of the 50 wells initially drilled, 23 are currently producing. The pressure is support by 04 injector wells, and daily production is estimated at approximately 12,000 bbl/d. To maximize oil production and minimize water production, the positions of injection wells were moved, which permitted to reduce the number of producing wells from 23 to 18. The result revealed that this scheme can maintained the pressure at desired levels of 2900 psi, until year 2040 and reversed the current trend in water production, which was 14,000 bbl/d. In the predicted scenarios, cumulative production will be maintain at 25,000 bbl/d with a daily production of around 18,000bbl of oil compared to formerly figure of 7000 bbl of water until 2040

Comparative Analysis of Space Efficiency in Contemporary Tall Buildings: Residential, Office, Hotel and Mixed-Use Functions

This paper offers an in-depth comparative analysis of space efficiency in contemporary tall towers, specifically focusing on residential, office, hotel and mixed-use functions (166 cases in total). To the best of current knowledge, no study in the existing literature has focused on this critical and topical subject. The findings underscore the pivotal importance of central core planning and prismatic building forms, which emerge as crucial design elements for optimizing space efficiency across all building types. Central core planning ensures the strategic placement of essential elements like elevators and stairwells, thereby minimizing wasted space and maximizing usable floor area. Meanwhile, prismatic building forms, characterized by their straightforward geometric shapes, facilitate more efficient construction processes and space usage. Average space efficiencies of residential, office, hotel and mixed towers were 76%, 71%, 81%, and 71%, whereas core area to GFA ratio were 19%, 26%, 16% and 26%, respectively. Values fluctuated from the lowest of 55% and 4% to the highest of 94% and 38%. By exploring these dimensions, this research offers valuable insights for the architects and developers, guiding them in the creation of tall buildings that are not only architecturally impressive but also economically viable and highly efficient. This comprehensive analysis serves as a critical resource, emphasizing the need for a balanced approach that considers core planning, structural integrity, and material choice in the design and construction of tall edifices. This holistic perspective is essential for professionals aiming to achieve the highest standards of efficiency and practicality in their architectural endeavors

A Study of an EOQ Model of Deteriorated Items with Pentagonal Dense Fuzzy Demand Rate

In this project work, we deal with an economic order quantity inventory model of deteriorating items under non-random uncertain demand. Here we consider the customers screen the fresh items during the selling period. After a certain period of time, the deteriorated items are sold at a discounted price. Firstly, we solve the crisp model, and then the model is converted into a fuzzy environment. Here we consider the pentagonal dense fuzzy, trapezoidal dense fuzzy, and triangular dense fuzzy for a comparative study. We have taken the numerical result using LINGO 18.0 software. Finally, sensitivity analysis and graphical illustration have been given to check the validity of the model

Forecasting Non-stationary Time Series Using Deep Learning in a Fuzzy Time Series Framework and its Application to Stock Markets

Non-stationary time series prediction is challenging due to its dynamic and complex nature. Fuzzy time series models offer a promising solution for forecasting such data, but a key challenge lies in partitioning the universe of discourse, which significantly impacts forecasting accuracy. Traditional fuzzy time series models often use equal-length interval partitioning, which is more suited for stationary data and limits their adaptability to non-stationary time series.  This paper introduces a novel variable-length interval partitioning method designed specifically for non-stationary time series. The developed method combines a Long Short-Term Memory (LSTM) Autoencoder with K-means clustering, enabling dynamic, data-driven partitioning that adapts to the changing characteristics of the data. The LSTM Autoencoder encodes the time series, which is clustered using K-means, and intervals are defined based on cluster centers. Furthermore, the Variable Length Interval Partitioning-based Fuzzy Time Series model (VLIFTS) is developed by incorporating this partitioning method and the concepts of Markov chain and transition probability matrix. In this model, fuzzy sets are viewed as states of a Markov chain, and transition probabilities are used in the forecasting phase. The model is validated on stock market indices Nifty 50, NASDAQ, S&P 500, and Dow Jones. Stationarity and heteroscedasticity are tested using Augmented Dickey-Fuller (ADF) and Levene's tests respectively. Statistical forecast accuracy metrics Root Mean Squared Error (RMSE) and Mean Absolute Percent Error (MAPE) show that VLIFTS significantly improves forecasting accuracy over traditional models. This hybrid approach enhances fuzzy time series modelling and can be applied to various non-stationary time series forecasting problems

W2,p-Regularity of Lp Viscosity Solutions to Fully Nonlinear Elliptic Equations with Low-Order Terms

In this paper, we consider the following fully nonlinear elliptic equation                                                                      F(D2u, Du, x) = f(x), where the operator F satisfies structure condition and the gradient of solution has Lploc growth rate particularly. We employ the technique from geometric tangential analysis whose basic principle is to transfer the good regularity of the recession operator to the original F by approximation methods and establish a prior local W2,p estimates for - Lp-viscosity solutions to the above equation. Mathematics Subject classification (2010): 35B45; 35R05; 35B65.

Evidence of a Large Debris Avalanche Event (22.0 Ma) from the Comondú Group on the Baja California Sur Peninsula, Mexico

The morphological, sedimentological, and microtextural characteristics of Miocene debris avalanche deposits which extend from the Punta Coyote to the vicinity of the city of La Paz, were studied along the eastern of the Baja California Peninsula. The debris avalanche deposits studied include a mixture of angular mega blocks whose composition comes from the deposits that make up the Comondú Group: pre-Comondú (red sandstones and conglomerates with intercalated ignimbrites), the Upper Unit (brownish sandstones, shales, and conglomerate), and breccia, with a predominance of jigsaw cracks, injection structures, and fault structures. These deposits were studied and analyzed considering the stratigraphic relationships between the rock formations present in the mega-blocks. Six stratigraphic sections were measured to describe the composition and morphology of the clastic components present in the mega-blocks of the debris avalanche. Two different units (m1 and m2), were identified in the debris avalanche deposits. Unit m1 is the oldest, with a thickness of 100m, and consists of a chaotic set of mega-blocks up to 100 m in diameter derived from the pre-Comondú Group, and Upper Unit. The deposits are highly heterolithic, with angular and highly fractured clasts at different scales. While the unit m2 consists principally of 20-100 m thick volcaniclastic layers dominated by poorly sorted, breccias and minor epiclastic deposits. According to stratigraphic relationships, the collapse occurred at 22.0 Ma. The debris deposit covers an area of 150 km2 and has an estimated volume of 1.3 km3. The characteristic suggests a transport mechanism with a disintegration of the mega-blocks and a contact/collision interaction. Where mega-blocks moved within a dense flow in a buffered manner, remaining consistent over long distances. The observed structures and textures suggest that the mega-blocks were mainly produced by the alteration and ingestion of older substrates by the avalanche of moving debris. The avalanche flowed over pre-existing topography excavated in the Comondú Group sequence, and flow indicators reveal a west-southwest direction, exhibiting a typical mountainous avalanche topography. The study of ancient debris avalanche events not only provides a deeper understanding of these natural phenomena but also contributes to the development of tools to predict, mitigate, and manage risk areas