•Analyzing the energy, exergy and CO2 emissions of the proposed system.•Reaching the energetic and exergetic round trip efficiencies of 78% and 58%.•Achieving the electrical efficiencies of 43% and ...64% in charge and discharge times.•Reduction of emissions by integrating the fuel cell and energy storage units.•Parametric analysis for scrutinizing five critical performance criteria.
In this work, a novel integrated system based on a combination of solid oxide fuel cell (SOFC) with compressed air energy storage (CAES) and turbocharger is presented for simultaneous production of domestic hot water and power in the scale of retail buildings for peak shaving applications. The SOFC subsystem is the primary power generation unit, which is coupled with CAES and other supporting auxiliary cycles. The energy, exergy, and emissions are quantified through parametric analysis for evaluating the overall system performance. The preliminary results for the scenario analyzed indicate a power generation of 272 kW during 4 h in off-peak period, as well as a power generation of 407 kW during 7 h in peak demand periods. The round trip energy and exergy efficiencies for the integrated system are 78% and 58%, respectively. Also, the overall emissions of the proposed integrated system is reduced by 0.06 kgCO2/kWh in comparison to the standalone SOFC system. The afterburner accounts for the main source of irreversibility and exergy destruction among all components. Overall, the integrated system is superior to the standalone SOFC system from energy, exergy and emissions perspectives.
•Round trip efficiency improvement by combining the desalination and storage units.•Simultaneous generation of the power and potable water during peak demand periods.•An efficient and green ...cogeneration system for using in warm and arid climates.•Waste heat recovery from the compressors and the turbine exhaust.•Impact of the maximum to minimum pressure ratio on performance and operational time.
Compressed air energy storage is one of two existing grid-scale energy storage technologies. It can be efficiently used in dry and warm climates, where providing both electricity and potable water is indispensable. A novel integration of compressed air energy storage and multi-effect desalination system is proposed to reduce energy dissipation, exergy destruction and provide power and potable water. Compression heat in the charging period is conveyed to the desalination unit; during discharging, the remaining energy in the turbine exhaust is reassigned to the desalination unit after passing through the recuperator. Round trip efficiency is thereby improved while providing peaking power and pure water. Besides, the effect of the maximum to minimum pressure ratio of the compressed air vessel on efficiency and the operational period of the system is studied for a particular set of circumstances. Results indicate that 38 kg/s potable water is produced during charging, whereas 80 MW electricity and 62.5 kg/s distilled water are concurrently generated during peak demand periods. As a result, 69.95% round trip efficiency and 9.47 performance ratio are obtained for the proposed hybrid system.
In today’s world, the significance of energy and energy conservation is a common knowledge. Wind towers can save the electrical energy used to provide thermal comfort during the warm months of the ...year, especially during the peak hours. In this paper, we propose a new design for wind towers. The proposed wind towers are installed on top of the buildings, in the direction of the maximum wind speed in the region. If the desired wind speed is accessible in several directions, additional wind towers can be installed in several positions. The proposed wind tower can also rotate and set itself in the direction of the maximum wind speed. In the regions where the wind speed is low, to improve the efficiency of the system a solar chimney or a one-sided wind tower can be installed in another part of the building in the opposite direction. Using transparent materials in the manufacturing of the proposed wind towers improves the use of natural light inside the building. The major advantage of wind towers is that they are passive systems requiring no energy for operation. Also, wind towers reduce electrical energy consumption and environmental pollution.
Microwave Ablation (MWA) is one of the most recent developments in the field of thermal therapy. This approach is an effective method for thermal tumor ablation by increasing the temperature above ...the normal physiological threshold to kill cancer cells with minimum side effects to surrounding organs due to rapid heat dispersive tissues. In the present study, the effects of the shape and size of the tumor on MWA are investigated. To obtain the temperature gradient, coupled bio-heat and electromagnetic equations are solved using a three-dimensional finite element method (FEM). To extract cellular response at different temperatures and times, the three-state mathematical model was employed to achieve the ablation zone size. Results show that treatment of larger tumors is more difficult than that of smaller ones. By doubling the diameter of the tumor, the percentage of dead cancer cells is reduced by 20%. For a spherical tumor smaller than 2 cm, applying 50 W input power compared to 25 W has no significant effects on treatment efficiency and only increases the risk of damage to adjacent tissues. However, for tumors larger than 2 cm, it can increase the ablation zone up to 21%. In the spherical and oblate tumors, the mean percentage of dead cells at 6 GHz is nearly 30% higher than that at 2.45GHz, but for prolate tumors, treatment efficacy is reduced by 10% at a higher frequency. Moreover, the distance between two slots in the coaxial double slot antenna is modified based on the best treatment of prolate tumors. The findings of this study can be used to choose the optimum frequency and the best antenna design according to the shape and size of the tumor.
•Provides an inverse analysis using meta-heuristic algorithms to estimate the properties of drug and tumor to personalize the treatment and overcome defects of previous research modeling.•Two ...different drug transport models study to evaluate the validity and usefulness of parameter estimation methods.•Higher sensitivity coefficients serve better in the estimation of the target parameters; the highest values occur near the tumor border.•Using the HPW method resulted in offers better solutions in minimizing the objective function and more appropriate responses in estimating the parameters.
One of the major drawbacks in mathematical modeling of the drug delivery in living species is application of a common value for a specific property such as diffusion coefficient of drug in tissue, while this property is unique for each person or species. Therefore, knowledge on the species-specific values of these properties can improve the process of drug delivery and treatment. Inverse problem methods can achieve these unique properties for each specimen. Estimation of the individual-specific drug and tumor parameters requires the evaluation of the drug concentration (the concentration of medical images) within the tumor tissue. Accordingly, in this paper, first, the drug transport equation in tumor is determined. Then, the sensitivity analysis is conducted to determine the appropriate area for selecting the drug concentration to estimate the drug and tumor parameters. Finally, the parameters estimated by meta-heuristic and hybrid meta-heuristic methods are compared. To enhance the validity of the methods, two different drug transport models are examined. The results indicate that the hybrid methods gave rise to more precise estimations, especially the hybrid particle swarm optimization (PSO) method with whale optimization algorithm (WOA) which offer more appropriate responses in the parameters estimation of two models.
Abstract
A deeper understanding of the tumor microenvironment (TME) and its role in metabolic activity at different stages of vascularized tumors can provide useful insights into cancer progression ...and better support clinical assessments. In this study, a robust and comprehensive multi-scale computational model for spatiotemporal transport of F-18 fluorodeoxyglucose (FDG) is developed to incorporate important aspects of the TME, spanning subcellular-, cellular-, and tissue-level scales. Our mathematical model includes biophysiological details, such as radiopharmaceutical transport within interstitial space via convection and diffusion mechanisms, radiopharmaceutical exchange between intracellular and extracellular matrices by glucose transporters, cellular uptake of radiopharmaceutical, as well as its intracellular phosphorylation by the enzyme. Further, to examine the effects of tumor size by varying microvascular densities (MVDs) on FDG dynamics, four different capillary networks are generated by angiogenesis modeling. Results demonstrate that as tumor grows, its MVD increases, and hence, the spatiotemporal distribution of total FDG uptake by tumor tissue changes towards a more homogenous distribution. In addition, spatiotemporal distributions in tumor with lower MVD have relatively smaller magnitudes, due to the lower diffusion rate of FDG as well as lower local intravenous FDG release. Since mean standardized uptake value (SUV
mean
) differs at various stages of microvascular networks with different tumor sizes, it may be meaningful to normalize the measured values by tumor size and the MVD prior to routine clinical reporting. Overall, the present framework has the potential for more accurate investigation of biological phenomena within TME towards personalized medicine.
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•The effect of continuous and discontinuous TPT on η is investigated.•The thermal performance factor of seven different turbulators is compared.•The effect of perforation on ...discontinuous twisted tapes turbulator is examined.•Discontinuous turbulator has a better effect on heat transfer and pressure drop.•The highest η was obtained for twisted turbulator with a circular perforation.
In this paper, the experimental effect of the continuous and discontinuous twisted tapes turbulator (perforated and non-perforated) on the inner side of the internal tube in the double heat exchangers on heat transfer, the friction coefficient, and thermal performance have been discussed. On discontinuous twisted tapes turbulator, 9 holes with different geometries, such as triangular, square, rectangular, circular, and diamond with the triangular arrangement, have been created on turbulator flat surfaces. The Reynolds range is investigated at 5500–10000, and working fluids are on the side of the inner tube and annular space is hot and cold water, respectively. Experimental results have shown that discontinuous turbulator has a better effect on heat transfer and pressure drop than continuous turbulator. As the discontinuous turbulator without a hole has an increase in heat transfer of 8.2 % and a reduction of 9.8 % in the pressure drop coefficient compared to the continuous turbulator. Then the effect of perforation on discontinuous twisted tapes turbulator was investigated. Experimental results show that perforated discontinuous turbulator with circular, square, rectangular, diamond and triangular perforation with the same hydraulic diameter as for discontinuous turbulator without perforation was 20.8 %, 15 %, 11 %, 8.7 %, 5 % increase in heat transfer and 27.7 %, 22.8 %, 17.3 %, 12.1 %, 5.5 % decrease in the coefficient of pressure drop, respectively. Therefore, according to the results, the best thermal performance was related to the perforated of perforated discontinuous twisted turbulator, discontinuous twisted turbulator, and continuously twisted turbulator were respectively.
Although intraperitoneal chemotherapy (IPC) has been suggested as a promising method for the management of peritoneal dissemination (PD) of ovarian or colorectal cancers, the actual clinical use of ...this method has been restricted due to such problems as poor drug penetration into the tumor and high side effects. It is, therefore, necessary to develop new strategies to improve the efficacy of this approach. In the present work, a new strategy is proposed based on intraperitoneal (IP) injection of thermosensitive liposomal doxorubicin (TSL-Dox) with triggered release by mild hyperthermia induced by high intensity focused ultrasound (HIFU). A computational model is developed to evaluate the proposed drug delivery system. Results show an order of magnitude increase in drug penetration depth into the tumor compared to the conventional IP delivery. Furthermore, the effects of thermal conditions applied to the tumor, TSL size, tumor vessel permeability, and tumor size are investigated. Results indicate an improved efficiency of the drug delivery by expanding the heated region, yet, it increases the risk of unintentional TSL drug load release in the peritoneal cavity. Results also indicate that smaller TSLs have better treatment outcome. However, there is a significant reduction in treatment efficacy for TSLs with sizes smaller than the vessel wall pore size. Thus, tuning the size of TSL should be based on the tumor microvascular permeability. The simulation results suggest that the TSL-Dox delivery system in smaller tumors is far advantageous than larger ones. Results of our model can be used as guidelines for future preclinical studies.
Nano-sized drug delivery systems (NSDDSs) offer a promising therapeutic technology with sufficient biocompatibility, stability, and drug-loading rates towards efficient drug delivery to solid tumors. ...We aim to apply a multi-scale computational model for evaluating drug delivery to predict treatment efficacy.
Three strategies for drug delivery, namely conventional chemotherapy (one-stage), as well as chemotherapy through two- and three-stage NSDDSs, were simulated and compared. A geometric model of the tumor and the capillary network was obtained by processing a real image. Subsequently, equations related to intravascular and interstitial flows as well as drug transport in tissue were solved by considering real conditions as well as details such as drug binding to cells and cellular uptake. Finally, the role of periodic treatments was investigated considering tumor recurrence between treatments. The impact of different parameters, nanoparticle (NP) size, binding affinity of drug, and the kinetics of release rate, were additionally investigated to determine their therapeutic efficacy.
Using NPs considerably increases the fraction of killed cells (FKCs) inside the tumor compared to conventional chemotherapy. Tumoral FKCs for two-stage DDS with smaller NP size (20nm) is higher than that of larger NPs (100nm), in all investigate release rates. Slower and continuous release of the chemotherapeutic agents from NPs have better treatment outcomes in comparison with faster release rate. In three-stage DDS, for intermediate and higher binding affinities, it is desirable for the secondary particle to be released at a faster rate, and the drug with slower rate. In lower binding affinities, high release rates have better performance. Results also demonstrate that after 5 treatments with three-stage DDS, 99.6% of tumor cells (TCs) are killed, while two-stage DDS and conventional chemotherapy kill 95.6% and 88.5% of tumor cells in the same period, respectively.
The presented framework has the potential to enable decision making for new drugs
computational modeling of treatment responses and has the potential to aid oncologists with personalized treatment plans towards more optimal treatment outcomes.
Probiotics administration in aquafeed is known to increase feed consumption and absorption due to their capacity to release a wide range of digestive enzymes and nutrients which can participate in ...digestion process and feed utilization, along with the absorption of diet components led to an increase in host’s health and well‐being. Furthermore, probiotics improve gut maturation, prevention of intestinal disorders, predigestion of antinutrient factors found in the feed ingredients, gut microbiota, disease resistance against pathogens and metabolism. The beneficial immune effects of probiotics are well established in finfish. However, in comparison, similar studies are less abundant in the shellfish. In this review, the discussions will mainly focus on studies reported the last 2 years. In recent studies, native probiotic bacteria were isolated and fed back to their hosts. Although beneficial effects were demonstrated, some studies showed adverse effects when treated with a high concentration. This adverse effect may be due to the imbalance of the gut microbiota caused by the replenished commensal probiotics. Probiotics revealed greatest effect on the shrimp digestive system particularly in the larval and early post‐larval stages, and stimulate the production of endogenous enzymes in shrimp and contribute with improved the enzyme activities in the gut, as well as disease resistance.
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