Generation Rate Research Articles

Design of positive pulse measurement while drilling system for mine rotary valve mud

Abstract For the drilling of directional wells and horizontal wells, to ensure that the drilling trajectory is drilled in the coal seam in the direction designed before drilling, it is necessary to transmit information without interrupting the drilling process. The drilling fluid pressure pulse is divided into positive pulse, negative pulse, and continuous wave. The positive pulse transmission system with the mechanical structure of the lifting valve is widely used because of its high pulse signal strength and long propagation distance, which can be used in deep wells. With the increase of the information measured in the formation, the lifting valve can not meet the needs of the current information transmission due to the linear motion of the mechanical structure and the low transmission rate. The rotary valve as the pressure signal generation source can improve the pulse generation rate. Therefore, this paper analyzes the working principle and signal generation principle of the rotary valve positive pulse system, and collects the directional data and natural gamma value of the field test.

A Study on the Growth and Physiological Toxicity Effects of the Combined Exposure of Microplastics and Cadmium on the Vicia faba L. Seedlings.

To investigate the toxicological effects of polystyrene microplastics (PS-MPs), cadmium (Cd), and their combined contamination on the growth and physiological responses of V. faba seedlings, this experiment employed a hydroponic method. The Hoagland nutrient solution served as the control, changes in root growth, physiological and biochemical indicators of V. faba seedlings under different concentrations of PS-MPs (10, 100mg/L) alone and combined with 0.5mg/L Cd. The results demonstrated that the root biomass, root vitality, generation rate of superoxide radicals (O2·-), malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity increased with increasing concentration under the influence of PS-MPs alone, while the soluble sugar content and peroxidase (POD) activity decreased. In the combined treatment with Cd, the trends of these indicators are generally similar to the PS-MPs alone treatment group. However, root vitality and SOD activity showed an inverse relationship with the concentration of PS-MPs. Furthermore, laser confocal and electron microscopy scanning revealed that the green fluorescent polystyrene microspheres entered the root tips of the V. faba and underwent agglomeration in the treatment group with a low concentration of PS-MPs alone and a high concentration of composite PS-MPs with Cd.

Multi-objective optimization design of high-pressure plate-fin ammonia boiler based on MO-SHERPA algorithm

With the rapid development of electrification, the high-pressure plate-fin ammonia boiler has been widely used as an effective thermal management solution, which has stimulated the demand for its structure design and optimization. The aim of this study was to establish a multi-objective optimization design method for high-pressure plate-fin ammonia boiler based on the hybrid and adaptive search strategy of MO-SHERPA and CFD simulation. Based on this method, a set of pareto-optimal solutions were obtained, and then the optimal configuration with lightest weight and high heat transfer performance was determined by calculating the deviation for weighted sum of comprehensive performance factor, entropy generation rate and structure weight. The effects of fin structural parameters of ammonia boiler were further examined on its performance. The results showed that increasing the spacing and height of offset strip fin and reducing its thickness could effectively improve the heat transfer performance. This study provides a theoretical method and some guidelines for the structural design of ammonia boiler with high operating pressure.

Built-in electric field in NiO-CuO heterostructures to regulate the hydroxide adsorption sites for 5-hydroxymethylfurfural electrooxidation assisted hydrogen production

The development of catalysts with suitable adsorption behavior for the reaction molecules and the elucidation of their internal structure-adsorption-catalytic activity relationships are crucial for the electrooxidation of 5-hydroxymethylfurfural (HMF). In this work, NiO-CuO heterostructures with a spontaneous built-in electric field (BEF) are specifically designed and used to regulate the OH− adsorption site for freeing up the active site of HMF for the HMF oxidation reaction (HMFOR). The mechanism driving electron pumping/accumulation of the BEF is examined by X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). Electrochemical data and theoretical calculations show that BEF modulates the adsorption energy and adsorption site of substrate molecules, thereby enhancing the performance of HMFOR and hydrogen evolution reaction (HER). Notably, the NiO-CuO electrode demonstrates high 2,5-Furandicarboxylic acid (FDCA) selectivity (99.76 %) and generation rate (13.79 mmol gcat−1 h−1). It only requires 1.33 V to obtain a current density of 10 mA cm−2 for HMFOR-coupled H2 evolution. This research introduces a novel approach by regulating the adsorption of reactive molecules for HMFOR-assisted H2 evolution.

Synergistic effect between ohmic contacts and localized surface plasmon resonance for enhancing CO2 photoreduction of BiOBr

The fast recombination rate of photogenerated carrier and short electron lifetime are the main factors affecting the CO2 reduction performance of BiOBr (BOB). The utilization of ohmic contacts and the localised surface plasmon resonance (LSPR) effect of metals can effectively solve the above problems. However, one mean alone is not ideal for improving the photocatalytic performance of BOB. Therefore, in this work, we reduced the metal Bi to the surface of BOB in an attempt to form a synergistic effect of ohmic contact and LSPR effect. DFT calculations confirm the ohmic contact between Bi and BOB. Meanwhile, electrochemical tests show that Bi/BOB-2 has a higher photocurrent density (1.1 μA/cm2), suggesting that the ohmic contact achieves ultrafast electron transfer from BOB to Bi under light. While the UV–Vis diffuse reflectance spectroscopy results show resonance absorption peaks from the LSPR effect of Bi, the TRPL results show that Bi/BOB-2 has a longer τave (3.05 ns), implying that longer-lived hot electrons are generated on the Bi surface. The synergistic effect of the two contributes to the efficient CO2 to CO transition on the catalyst surface. As a result, Bi/BOB-2 exhibites a 4.37-fold higher CO generation rate (11.45 μmolg-1 h−1) than that of pure BOB (2.62 μmolg-1 h−1) under light. This study provides a new blueprint for the design of BiOBr-based materials for efficient photocatalytic reduction of CO2.

A new practical physical layer secret key generation in the presence of an untrusted relay

Physical layer secret key generation (SKG) has recently been introduced as a lightweight and efficient solution for sixth-generation (6G) networks. In this area, schemes based on local random generators are used for high-rate key generation. One of these schemes is random phase injection, where channel probe signals with random phases are exchanged between communication parties (source and destination). This paper proposes an SKG scheme in the presence of an untrusted relay, which helps the SKG process while cannot extract the secret key. To make the scheme operational, for the first time, the channel probe signals are considered discrete random phase based on M-PSK signals and a multi-bit quantizer is used in the reception. In addition, to reduce the key error rate, quantization with guard bands (GB) is used for key extraction. For such a scenario, we derive expressions for key agreement rate, key mismatch rate (KMR), key discarding rate (KDR) and key generation rate (KGR). Additionally, for the first time, this work examines the context of geometric secrecy for the proposed discrete phase key generation scheme for both direct and relaying scenarios. Through simulations, several engineering insights are presented to enhance the quality of the proposed SKG and its security.

Kinetic analysis and back propagation neural network model for shelf-life estimation of stabilized rice bran

To establish a general model for predicting shelf-life of stabilized rice bran, different samples with varying residual enzyme activity, water activity (aw), and packaging materials were used, and hot air assisted-radio frequency (HA-RF) heating was applied as stabilization method. Free fatty acids (FFA) were recorded during storage at different temperatures and kinetic analysis was conducted to compare the effects of different conditions on rice bran shelf-life. FFA content increased rapidly during storage, and higher aw and lipase (LA) activity corresponded to a higher FFA generation rate. Only the increase in FFA of samples with low LA activity (≤30 mg/g) and aw (≤0.3) conformed to Zero-order model, while that of other samples conformed to Fractional Conversion model. For the inhibitory effect of packaging materials on the generation of FFA, BOPP/Kraft-paper/PE > PA/PE > PET/PE > LDPE. A back propagation neural network (BPNN) model was also constructed to predict rice bran shelf-life, which employing LA activity, aw, packaging materials, and storage temperature as input parameters. The BPNN model trained by Levenberg–Marquardt achieved the best prediction performance, with coefficient of determination (R2) of 0.996 and root mean square error (RMSE) of 2.077. Rice bran packaged by BOPP/Kraft-paper/PE with LA activity of 20 mg/g and aw of 0.2 had the longest shelf-life of 147 d at 25 °C. This model is of great help in predicting the shelf-life of stabilized rice bran and guiding the development of rice bran stabilization process.

PH-Optimized Biomethane Production: Evaluating Carrier Materials for Ex-situ Biomethanation

Choosing the appropriate carrier material for ex-situ biomethanation is a critical factor to consider when developing biogas upgrading technologies. The chosen material for biomethanation in a biotrickling filter reactor functions as a substrate that immobilises microorganisms, which act as catalysts in the reaction for producing biomethane. This study conducted experiments on waste-derived materials, including glass foam and vulcanised wood ash material, in addition to polyurethane foam and expanded clay pellets. Pretreratment of wood ash was done to lower the pH of material. The manometric test measured the rate of CH4 generation by quantifying pressure fluctuations. The validity of these results was confirmed by analysing product gas samples using a Shimadzu Nexis GC-2030 gas chromatograph, which was equipped with two parallel lines, a flame ionisation detector (FID) and a thermal conductivity detector (TCD). In order to enhance the biomethane concentration in the end product, two strains of Methanobacterium alcaliphilum were evaluated alongside biogas sludge as the inoculum. These strains of microorganisms are methanogens that utilise hydrogen and can thrive in a high pH environment. Thus, they have the potential to demonstrate improved biomethane production outcomes when a vulcanised wood ash filter is used as the carrier material.

The organic HTL in highly efficient germanium-alloyed CsSnI3 perovskite solar cell: a modelling and computational analysis

It is usually anticipated that perovskites will be an appealing material for extremely effective solar cells. However, its practical applications are constrained by its hazardous properties and stability. Thus, CsSn0.5Ge0.5I3, a more environmentally benign substitute for toxic lead-based perovskites, provides superior stability in solar cells. This work reports on the numerical modeling and computational analysis of a heterostructure CsSn0.5Ge0.5I3, with TiO2 and D-PBTTT-14 serving as the electron and hole transport layers, respectively. The introduction of D-PBTTT-14 as a hole transport layer was motivated by its superior stability over existing organic HTLs. Furthermore, the higher electron–hole pair generation rate and very favorable absorption coefficients of each layers manifested improved efficiency. Various parameters were examined to enhance the newly designed solar cell performance such as: thickness, defect density, doping density, coefficient of radiative recombination, defect at interface, shunt and series resistance, front and back contacts, and operating temperature. Perovskite solar cells with their current architecture have the potential to achieve a current density (Jsc) of 28.31 mA cm−2, an open-circuit voltage (Voc) of 1.24 V, a fill factor (FF) of 85.90%, and efficiency of 30.27%.

Kinetics of Obtaining Microalgal Biomass and Removal of Organic Contaminants in Photobioreactors Operated with Microalgae—Study Case: Treatment of Wastewater from a Poultry Slaughterhouse

Increases in poultry industry production have resulted in the generation of more hazardous effluents with high nitrogen and chemical oxygen demand (COD) concentrations. It is necessary to develop more efficient technologies in terms of water purification without the need to increase the volumes of commonly used reactors. This work analyzed the addition of micronutrients (Mo, Zn, Cu, and Mn) for the cultivation of the microalgae Chlorella spp. and Spirulina maxima in poultry wastewater. The effects of micronutrients on the production of biomass and algal cells were also assessed. For the Chlorella species, removal efficiencies of up to 99.14% for COD and 99.33% for nitrogen were achieved; for the Spirulina strain, these efficiencies were 98% for COD and 99% for nitrogen. The modified Gompertz equation was used to analyze the kinetic parameters. For both microalgae, the R2 values were greater than 98%. The results indicated that the dose with the highest algal cell generation rate was dose 2 for Chlorella spp., at 4.35 days, and dose 1 for Spirulina maxima, at 6.26 days. Microalgae are biological alternatives suitable for wastewater treatment, and their pollutant removal efficiency can increase with the addition of micronutrients, which has additional benefits for the production of valuable biomasses for industrial applications.

Synergistic effect of Ru single atom and nanoparticle on photothermal methane dry reforming reaction

Dry reforming of methane is indeed an attractive pathway for converting greenhouse gases into syngas. However, owing to the strong-endothermic nature of this reaction, high reaction temperature is commonly involved which causes high energy consumption, catalytic deactivation by sintering of active species, and/or coke formation. Herein, a RuSA+NP/TiO2 composite catalyst consisting of uniformly dispersed Ru nanoparticles (RuNP) and Ru single atoms (RuSA) on TiO2 sheet is fabricated. This catalyst demonstrates remarkable syngas generation rates of 1380 mmol g-1h−1 for CO and 933 mmol g-1h−1 for H2 at 500 °C under light irradiation. It is concluded that the presence of Ru single atoms modulates the electronic structure of catalyst, reducing energy barrier in the DRM process. Additionally, the electron-deficient Ru nanoparticles provide effective sites for CH4 dissociation. Light irradiation is found to reduce the apparent activation energy (Ea) of DRM and enhance durability of catalyst by retarding coking process.

High-efficiency solar-driven H2 generation by three-dimensionally ordered macroporous heterojunction structure

Development of high-efficiency photocatalyst for solar-driven hydrogen (H2) generation still encounters significant challenges. The biomimetic materials with a multistage structure are advantageous for enhancing light harvesting and utilization, as well as facilitating the efficient separation of photon-generated electron-hole pairs, thus play a crucial role in improving photocatalytic efficiency. Herein, the present study demonstrates the design of ZnIn2S4-TiO2 (ZIS/T) biomimetic multistage heterostructure with three-dimensionally ordered macroporous (3DOM) structure for efficient H2 generation. The optimal ZIS/T heterostructure photocatalyst by carefully regulating the interface structure exhibits the superior H2 generation rate of 9.05 mmol·h−1·g−1, surpassing the rates observed in 3DOM TiO2 and ZnIn2S4 samples by 11 and 4.1 times, respectively. The significantly improved photocatalytic efficiency was primarily attributed to the unique multistage structure that provide with abundant reactive sites and excellent mass transfer ability. Furthermore, the slow photon effect induced by the particular 3DOM multistage heterojunctions promote separation of photon-generated carriers. This resultant work provides a novel strategy for the construction of photo-confined heterojunction photocatalysts with enhanced photocatalytic performance through interfacial engineering.

Generation Control of Multi-Area Multi-Source Power System using Fire-Fly Algorithm

This article presents automatic generation control (AGC) of an interconnected three area power system having different production sources such as hydropower, thermal and gas power plants. The control areas are provided with single reheat turbine and generation rate constraints of 3%/min. An attempt has been made to apply a Proportional derivative–Proportional integral derivative (PD–PID) cascade controller in AGC. Controller gains are optimized simultaneously using more robust and powerful evolutionary computational technique Firefly Algorithm (FFA). Performance of classical controllers such as Proportional Integral (PI) and Proportional Integral Derivative (PID) controller are investigated and compared with PD–PID cascade controller. Investigations reveal that PI, and PID provide more or less same response where as PD–PID cascade controller provides much better response than the later. The system dynamic performances are studied with 1% and 2% step load perturbation in Area1. Sensitivity analysis reveals that the FFA optimized PD–PID Cascade controller parameters obtained at nominal condition of loading, size and position of disturbance and system parameter (Inertia constant, H) are robust and need not be reset with wide changes in system loading, size, position of disturbance and system parameters.

Cobalt Phosphide-Supported Single-Atom Pt Catalysts for Efficient and Stable Hydrogen Generation from Ammonia Borane Hydrolysis.

Ammonia borane (AB) has emerged as a promising chemical hydrogen storage material. The development of efficient, stable, and cost-effective catalysts for AB hydrolysis is the key to achieving hydrogen energy economy. Here, cobalt phosphide (CoP) is used to anchor single-atom Pt species, acting as robust catalysts for hydrogen generation from AB hydrolysis. Thanks to the high Pt utilization and the synergy between CoP and Pt species, the optimized Pt/CoP-100 catalyst exhibits an unprecedented hydrogen generation rate, giving a record turnover frequency (TOF) value of 39911 and turnover number of 2926829 at room temperature. These metrics surpass those of all existing state-of-the-art supported metal catalysts by an order of magnitude. Density functional theory calculations reveal that the integration of single-atom Pt onto the CoP substrate significantly enhances adsorption and dissociation processes for both water and AB molecules, thereby facilitating hydrogen production from AB hydrolysis. Interestingly, the TOF value is further elevated to 54878 under UV-vis light irradiation, which can be attributed to the efficient separation and mobility of photogenerated carriers at the Pt-CoP interface. The findings underscore the effectiveness of CoP as a support for single-atom metals in hydrogen production, offering insights for designing high-performance catalysts for chemical hydrogen storage.

Utilizing the immanent chloride ions in wastewater for reactive chlorine species photogeneration towards effective ammonia nitrogen removal

Utilizing the immanent salt (Cl–) in wastewater to generate reactive chlorine species (RCS) satisfies the future needs for sustainable, on-demand, and decentralized ammonia nitrogen (NH4+-N) removal. The microstructural evolution of bismuth oxychloride (BiOCl) photocatalyst under irradiation benefits for overcoming the competition between Cl– and H2O oxidation and achieving high N2 selectivity. Herein, internal electric field (IEF) engineering by carbon doping is applied to promote photocatalytic RCS generation rate over BiOCl. The carbon dopant not only enhances the IEF intensity of BiOCl by a factor of 2.1 times for carrier dynamics promotion, but also improves Cl– oxidation against H2O oxidation. An RCS production rate of 0.23 mg/L min−1 is realized over carbon-doped BiOCl (C-BiOCl) through the accelerated interaction between lattice and environmental Cl–, which is twice that of the undoped BiOCl (0.11 mg/L min−1). The relation between IEF intensity and RCS generation rate over C-BiOCl manifests a correlation coefficient of 0.96. Effective NH4+-N degradation with N2 selectivity of >99% is validated. The system is competent in dealing with saline NH4+-N wastewater with a wide range of NH4+-N (20∼200 mg N/L) and NaCl (6∼10 g/L) concentrations. In the treatment of realistic landfill leachate (884 mg N/L NH4+-N), C-BiOCl displays a photocatalytic NH4+-N removal efficiency of up to 95.6% while maintaining the NO2−-N (∼2 mg N/L) and NO3−-N (∼40 mg N/L) levels. This system provided an interesting and innovative idea for wastewater self-purification.

Performance improvement of a rotating gas separator for electrical submersible pump considering entropy generation method

The utilization of Electrical Submersible Pumps (ESPs) stands as one of the foremost methods in artificially extracting oil, primarily within the oil industry. Under typical conditions, the pump encounters a two-phase flow of oil and gas. Should the gas phase within this mixture surpass an acceptable threshold, it can lead to a significant decline in performance and inflict detrimental damage upon the pump. To address this issue, the incorporation of a gas separator unit, one of the pivotal components within ESPs, is imperative at the pump's inlet section. Enhancing the gas separator unit holds paramount importance for ensuring pump safety and optimizing performance, particularly in wells with elevated gas contents.The conventional approach to calculating hydraulic losses in turbomachinery, relying on pressure drop calculations, often falls short in pinpointing the precise locations of losses. This paper delves into enhancing gas separator performance by augmenting gas separation efficiency through the application of the entropy generation method and leveraging the second law of thermodynamics. To achieve this, pivotal entropy-generating geometrical parameters of the gas separator were identified as the design variables necessary for forming the Taguchi sample space. Numerical simulations were conducted utilizing steady three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations for incompressible fluid flow, coupled with a turbulence model. Results indicate that the gas separation efficiency (GSE) of the initial model surged from 45.6% to 88% in the improved sample, albeit with a concurrent rise in entropy generation rate (EGR) from 209 W/K to 243.1 W/K. To establish a more comprehensive criterion for analysis, the ratio of GSE to EGR was employed as an objective function. This ratio quantifies the efficiency of gas separation per unit of energy loss, and it escalated from 0.218 in the primary sample to 0.362 in the improved sample, representing a 66% increase. This signifies that despite simultaneous increases in EGR and GSE, the rate of energy loss per unit of gas separation has diminished. Furthermore, the heightened EGR in the improved sample can be attributed to an increase in total volume, leading to an expanded contact surface area and consequently an elevation in total entropy. This investigation underscores the advantages of the entropy generation method, particularly in delineating the precise location and magnitude of energy dissipation within the rotating gas separator.

In Situ Construction of CuTCPP/Bi4O5Br2 Hybrids for Improved Photocatalytic CO2 and Cr(VI) Reduction.

Global warming and heavy metal pollution pose tremendous challenges to human development, and photocatalysis is considered to be an effective strategy to solve these problems. Herein, copper(II) tetra (4-carboxyphenyl) porphyrin (CuTCPP) molecules were successfully in situ loaded onto Bi4O5Br2 by a hydrothermal approach. A series of experimental results show that the light absorption capacity and photogenerated carrier separation efficiency were synchronously enhanced after the construction of CuTCPP/Bi4O5Br2 composites. Hence, the as-prepared composites possess significantly improved photocatalytic ability for both CO2 and Cr(VI) reduction. Specifically, CuTCPP/Bi4O5Br2-2 achieves a CO generation rate of 17.14 μmol g-1 under 5 h irradiation, which is twice as high as that of Bi4O5Br2 (8.57 μmol g-1). Besides, the optimized CuTCPP/Bi4O5Br2-2 also exhibits a removal rate of 61.87% for Cr(VI) within 100 min under irradiation. Furthermore, the mechanism of CO2 and Cr(VI) photoreduction was explored by in situ Fourier transform infrared spectroscopy and capture experiments, respectively. This work can be a reference toward the construction of photocatalysts with high activity for solar energy conversion.

Non-Equilibrium Long-Wave Infrared HgCdTe Photodiodes: How the Exclusion and Extraction Junctions Work Separately.

The cooling requirement for long-wave infrared detectors still creates significant limitations to their functionality. The phenomenon of minority-carrier exclusion and extraction in narrow-gap semiconductors has been intensively studied for over three decades and used to increase the operating temperatures of devices. Decreasing free carrier concentrations below equilibrium values by a stationary non-equilibrium depletion of the device absorber leads to a suppression of Auger generation. In this paper, we focus on analyzing exclusion and extraction effects separately, based on experimental and theoretical results for a HgCdTe photodiode. To carry out an experiment, the n+-P+-π-N+ heterostructure was grown by metal organic chemical vapor deposition on CdTe-buffered GaAs substrate. In order to separate the extraction and exclusive junctions, three different devices were evaluated: (1) a detector etched through the entire n+-P+-π-N+ heterostructure, (2) a detector made of the P+-π photoconductive junction and (3) a detector made of the π-N+ photodiode junction. For each device, the dark current density-voltage characteristics were measured at a high-temperature range, from 195 K to 300 K. Next, the carrier concentration distribution across the entire heterostructure and individual junctions was calculated using the APSYS simulation program. It was shown that when the n+-P+-π-N+ photodiode is reverse biased, the electron concentration in the π absorber drops below its thermal equilibrium value, due to the exclusion effect at the P+-π junction and the extraction effect at the π-N+ junction. To maintain the charge neutrality, the hole concentration is also reduced below the equilibrium value and reaches the absorber doping level (NA), leading to the Auger generation rate's reduction by a factor of 2ni/NA, where ni is the intrinsic carrier concentration. Our experiment conducted for three separate detectors showed that the exclusion P+-π photoconductive junction has the most significant effect on the Auger suppression-the majority of the hole concentration drops to the doping level not only at the P+-π interface but also deep inside the π absorber.

Characterized on hydrogen properties and mechanism of Al–Sn–Bi composite powder in salt solutions

Using low-melting point elements to promote the Al/H2O reaction has garnered considerable attention because it is an economical approach to hydrogen supply. Herein, .Al–Sn–Bi composite powder was prepared through milling. The Al–Sn–Bi composite powder and the hydrolysate were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that the hydrolysis products is primarily AlOOH. The properties of the Al/H2O reaction were systematically characterized in salt solutions. Results show that the presence of Sn and Bi is beneficial to achieve short introduction times and large Al/H2O reaction rates. The hydrogen generation rate of the Al–Sn–Bi composite is 4566 mL min−1 g−1 and 3600 mL min−1·g−1 with NaCl and Na2SO4 solutions, respectively and the hydrogen production efficiency can reach 100% in 1 min. Additionally, the mechanism of Sn and Bi promoting Al/H2O reaction was characterized by density functional theory (DFT) calculations. The DFT calculations show that Sn and Bi replace 1/8 ML, 1/4 ML and 1/2 ML surface atoms of Al (111), the surface chemical potential increases with increasing doping concentration, and the electrode potential decreases with increasing doping concentration. The presence of Sn and Bi increases the surface chemical potential and reduces the electrode potential, this is conducive to the microcell reaction and promotes the Al/H2O reaction.

Analyzing Temperature Distributions and Gradient Behaviors for Early-Stage Tumor Lesions in 3D Computational Model of Breast

The computational modelling and analysis of internal and external temperature distributions and their gradients, associated with the first stage of mammary tumors, was performed to relate thermal parameters to relevant tumor characteristics. A realistic 3D geometric model of breast anatomy was used to simulate tumor cases that were characterized in real life at their primary clinical stage. The thermophysical parameters of three tumors were extracted to implement the models; a fourth case without a tumor was used as a reference to provide quantitative measurements of temperature increases and gradient changes. The analysis considered superficial and internal temperature distributions and gradients, computed throughout specific paths. Finally, an evaluation was made of the ability of the thermometric technologies available today to detect the changes estimated in simulations. Maximum temperature increments in the range of 2.30 to 3.20 °C and in the range of 0.15 to 0.30 °C were found on internal and superficial paths, respectively. Internal gradient peak magnitudes fluctuated within the range of 0.34 to 1.14 °C/mm. Thermal results indicated a direct correlation between tumor size and temperature rise. Nevertheless, gradient results showed that the heat generation rate, an indicator of tumor malignancy, was directly proportional to internal gradient maximum peaks, which were related to tumor boundaries regardless of tumor size.