Characteristics of heat transfer and flow of Newtonian and non-Newtonian fluids through porous walls and in porous media are studied due to their wide range of applications including geothermal reservoirs,heat exchang...Characteristics of heat transfer and flow of Newtonian and non-Newtonian fluids through porous walls and in porous media are studied due to their wide range of applications including geothermal reservoirs,heat exchangers,marine propulsion,and aerodynamics.The current study investigates the characteristics of heat transport in a reactive third-grade fluid,moving through permeable parallel plates,with uniform suction/injection velocity.The two permeable,parallel plates are maintained at the same,constant temperature.After being transformed into its dimensionless equivalent,governing equations are solved by employing the Least Squares Method(LSM).The LSM results are further validated with numerical solutions for temperature and velocity.The impact of cross-flow Reynolds number,Peclet number,heat generation parameter,non-Newtonian parameter,and Brinkman number on entropy generation,velocity,temperature,and Bejan number are investigated.Theresults indicate that temperature distribution is significantly influenced by the third-grade fluid parameter.The maximum temperature drops from almost 0.12 to 0.10 as the third-grade fluid parameter increases from0.05 to 0.4.When the cross-flow Reynolds number is raised from 0.05 to 3,the maximum temperature drops from 0.12 to around 0.09.Temperature is strongly influenced by the heat generation parameter.A greater understanding of the thermal characteristics necessary for the design of a variety of systems,such as heat exchangers,marine propulsion,aerodynamic systems,etc.,may be gained from the findings of the current study.展开更多
This paper introduces the effect of heat absorption(generation)and suction(injection)on magnetohydrodynamic(MHD)boundary-layer flow of Casson nanofluid(CNF)via a non-linear stretching surface with the viscous dissipat...This paper introduces the effect of heat absorption(generation)and suction(injection)on magnetohydrodynamic(MHD)boundary-layer flow of Casson nanofluid(CNF)via a non-linear stretching surface with the viscous dissipation in two dimensions.By utilizing the similarity transformations,the leading PDEs are transformed into a set of ODEs with adequate boundary conditions and then resolved numerically by(4–5)^(th)-order Runge-Kutta Fehlberg procedure based on the shooting technique.Numerical computations are carried out by Maple 15 software.With the support of graphs,the impact of dimensionless control parameters on the nanoparticle concentration profiles,the temperature,and the flow velocity are studied.Other parameters of interest,such as the skin friction coefficient,heat,and mass transport at the diverse situation and dependency of various parameters are inspected through tables and graphs.Additionally,it is verified that the numerical computations with the reported earlier studies are in an excellent approval.It is found that the heat and mass transmit rates are enhanced with the increasing values of the power-index and the suction(blowing)parameter,whilst are reduced with the boosting Casson and the heat absorption(generation)parameters.Also,the drag force coefficient is an increasing function of the powerindex and a reduction function of Casson parameter.展开更多
Several new techniques in the field of heat transfer in fluids have opened new avenues for studying the heat transfer effects in nanofluids and thermodynamic flow parameters, leading to novel applications. There have ...Several new techniques in the field of heat transfer in fluids have opened new avenues for studying the heat transfer effects in nanofluids and thermodynamic flow parameters, leading to novel applications. There have been studies on nanofluids, including metal, ceramic and magnetic nanoparticles mixed with base fluids such as Water, Kerosene, and Ethylene glycol. However, research on fluids employing semiconductor nanoparticles as supplements to base fluids to generate nanofluids and hybrid nanofluids is limited. For the investigation, Gallium nitrite, a binary semiconductor with excellent heat convection, is together with Cu metal nanoparticles and Al<sub>2</sub>O<sub>3</sub> ceramic nanoparticles separately in the base fluid Ethylene glycol (EG) to form hybrid nanofluids. The effects of convective boundary conditions, thermal radiation, heat source/sink, suction/injection, and activation energy on three-dimensional Williamson MHD hybrid nanofluid flow of Cu + GaN + EG, Al<sub>2</sub>O<sub>3</sub> + GaN + EG, and Cu + Al<sub>2</sub>O<sub>3</sub> + EG are investigated on a stretched sheet with porosity. A similarity transformation is performed on the governing equations to transform them into dimensionless ordinary differential equations ODEs. Numerical analysis is carried out in MATLAB utilizing bvp5c and the shooting technique. The variations of velocity, temperature, and concentration profiles as a function of different physical effects are presented graphically with dimensionless parameters and explained the variations scientifically. As varied with different parameters, the values of the Skin-friction coefficient, Nusselt number, and Sherwood number are mentioned in the table.展开更多
The aim of this work is to study the effect of non-uniform single and double slot suction/injection into a steady mixed convection boundary layer flow over a vertical cone, while the axis of the cone is inline with th...The aim of this work is to study the effect of non-uniform single and double slot suction/injection into a steady mixed convection boundary layer flow over a vertical cone, while the axis of the cone is inline with the flow. The governing boundary layer equations are transformed into a non-dimensional form by a group of non-similar trans- formations. The resulting coupled non-linear partial differential equations are solved nu- merically by employing the quasi-linearization technique and an implicit finite-difference scheme. Numerical computations are performed for different values of the dimensionless parameters to display the velocity and temperature profiles graphically. Also, numerical results are presented for the skin friction and heat transfer coefficients. Results indicate that the skin friction and heat transfer coefficients increase with non-uniform slot suction, but the effect of non-uniform slot injection is just opposite.展开更多
The work presented herein investigates the velocity, heat transfer, Nusselt number and skin friction profiles involved in boundary layer flow past a moving vertical porous plate. Similarity transformations are employe...The work presented herein investigates the velocity, heat transfer, Nusselt number and skin friction profiles involved in boundary layer flow past a moving vertical porous plate. Similarity transformations are employed to convert the governing nonlinear unsteady momentum and energy equations from their partial differential equation forms to boundary value ordinary differential equations. The resulting equations are then solved numerically by the Runge-Kutta fourth order method with the help of a shooting technique. Several features of the flow and heat transfer characteristics for different values of problem parameters are analyzed and discussed. These include the effects of the radiation parameter (R), suction and injection parameter (c), Grashof (Gr) and Prandtl (Pr) numbers on the flow and heat profiles. Numerical results show the impact of blowing and sucking as well as radation on boundary layer flows of this type. Both the skin frictions as well as the heat transfer rate are also significantly related to the radiation parameter. For all these cases;the numerical results are found to be in agreement with the physics of the problem.展开更多
Heat and mass transfer in vertical porous microchannels plays a crucial role in the design of micro heat exchangers and the cooling of micromechanical and microelectronic systems.When electroosmotic and electromagneto...Heat and mass transfer in vertical porous microchannels plays a crucial role in the design of micro heat exchangers and the cooling of micromechanical and microelectronic systems.When electroosmotic and electromagnetohydrodynamic(EO-EMHD)effects are incorporated,these channels enable active flow manipulation,mixing,and thermal regulation in Lab-on-a-Chip(LOC)devices,thereby broadening the scope of microscale cooling applications.This study investigates the effect of wall suction/injection on unsteady EMHD natural convection flow in a vertical microchannel,accounting for heat and mass transfer mechanisms.The dimensionless governing equations were formulated and solved analytically using appropriate initial and boundary conditions.Due to the coupled nature of the Soret and Dufour effects,a perturbation approach was employed to decouple the governing equations,which were then transformed from partial differential equations(PDEs)into ordinary differential equations(ODEs)using the Laplace Transform technique.Analytical expressions for velocity,temperature,and concentration were obtained in the Laplace domain,along with derived quantities such as skin friction,Nusselt number,and Sherwood number,evaluated through the Riemann-sum approximation.A MATLAB program was developed to examine the effects of key parameters including thermal radiation,Soret number,Dufour number,Grashof number,modified Grashof number,electric field strengths in the x and z directions,and the Hartmann number on the transport characteristics under suction and injection conditions.The results reveal that increasing the radiation parameter enhances the temperature and velocity but decreases the concentration.Similarly,higher E_(z),Gr,and Gm values lead to higher velocities,while increases in E_(x) and M suppress fluid motion.The findings provide physical insight into electro-magnetically driven convective transport in microchannels,highlighting the influence of cross-diffusion,radiation,and field effects on flow and thermal performance,offering valuable guidance for the design and optimization of Lab-on-a-Chip cooling systems.展开更多
Large language models(LLMs)have revolutionized AI applications across diverse domains.However,their widespread deployment has introduced critical security vulnerabilities,particularly prompt injection attacks that man...Large language models(LLMs)have revolutionized AI applications across diverse domains.However,their widespread deployment has introduced critical security vulnerabilities,particularly prompt injection attacks that manipulate model behavior through malicious instructions.Following Kitchenham’s guidelines,this systematic review synthesizes 128 peer-reviewed studies from 2022 to 2025 to provide a unified understanding of this rapidly evolving threat landscape.Our findings reveal a swift progression from simple direct injections to sophisticated multimodal attacks,achieving over 90%success rates against unprotected systems.In response,defense mechanisms show varying effectiveness:input preprocessing achieves 60%–80%detection rates and advanced architectural defenses demonstrate up to 95%protection against known patterns,though significant gaps persist against novel attack vectors.We identified 37 distinct defense approaches across three categories,but standardized evaluation frameworks remain limited.Our analysis attributes these vulnerabilities to fundamental LLM architectural limitations,such as the inability to distinguish instructions from data and attention mechanism vulnerabilities.This highlights critical research directions such as formal verification methods,standardized evaluation protocols,and architectural innovations for inherently secure LLM designs.展开更多
Background:Penile augmentation through injectable substances is becoming increasingly common.A growing number of aesthetic clinics are developing penile enlargement procedures using various injectable materials.Althou...Background:Penile augmentation through injectable substances is becoming increasingly common.A growing number of aesthetic clinics are developing penile enlargement procedures using various injectable materials.Although these procedures are now performed in more controlled and medically supervised environments,their long-term outcomes remain poorly understood.The promotion of such medical treatments contributes to an increasing interest among adult males in self-injection as a method to alleviate psychological distress associated with penile size concerns.At the same time,access to injectable substances through unofficial or unregulated sources has become increasingly easy.Tor our knowledge,we report the first documented case of self-injection with Garamycin®(gentamicin)cream,contributing to the literature on the often multidisciplinary management of penile enlargement injections,a field still lacking well-established guidelines.Case Description:This case report describes a young patient who self-injected Garamycin®into the penis for the purpose of enlargement.He presented to our urology department with worsening symptoms,including severe and poorly tolerated pain.His primary request was prompt relief of pain while preserving,as much as possible,the aesthetic appearance and functional integrity of his penis.This case required a multi-stage surgical approach to salvage the penis and preserve both its structural integrity and functional outcome.Conclusions:To our knowledge,this case report documents the first reported instance of Garamycin®injection performed for the purpose of penile enlargement.It provides insight into the clinical course of such penile cream injections,demonstrates that a two-stage scrotal flap can achieve both functional and aesthetic outcomes,and highlights the importance of comprehensive management particularly addressing the traumatic impact of penile deformity secondary to inflammation and/or infection,as well as the body dysmorphic concerns often associated with these cases.展开更多
While Large Language Models(LLMs)possess the capability to perform a wide range of tasks,security attacks known as prompt injection and jailbreaking remain critical challenges.Existing defense approaches addressing th...While Large Language Models(LLMs)possess the capability to perform a wide range of tasks,security attacks known as prompt injection and jailbreaking remain critical challenges.Existing defense approaches addressing this problem face challenges such as the over-refusal of prompts that contain harmful vocabulary but are semantically benign,and the limited accuracy improvement inmachine learning-based approaches due to the ease of distinguishing benign prompts in existing datasets.Therefore,we propose a multi-LLM agent framework aimed at achieving both the accurate rejection of harmful prompts and appropriate responses to benign prompts.Distinct from prior studies,the proposed method adopts In-Context Learning(ICL)during the learning phase,presenting a novel approach that obviates the need for computationally expensive parameter updates required by conventional fine-tuning.To demonstrate the proposed method’s capability for rapid and easy deployment,this study targets LLMs with insufficient alignment.In the experiments,macro-averaged binary classification metrics were used to comprehensively evaluate harmfulness detection.Experimental results using three LLMs demonstrated that the proposed method achieved performance that surpassed four baselines across all evaluation metrics for the target LLMs,evidencing significant effectiveness with an average improvement of 16.6 points in F1-score compared to the vanilla models.The significance of this study lies in the proposal of a novel approach based on ICL that does not require parameter updates.This framework offers high sustainability in practical deployment,as it allows for the adaptive enhancement of detection performance against continuously evolving attack methods solely through the accumulation of logs,without the necessity of retraining the LLM itself.By mitigating the trade-off between safety and utility,this research contributes to the implementation of robust LLMs.展开更多
Powder-Fueled Water Ramjet Engine(PFWRE)is the most promising powerplant in underwater high-speed propulsion.However,the effect of powder injection mode on its performance and the mechanism of this effect are not well...Powder-Fueled Water Ramjet Engine(PFWRE)is the most promising powerplant in underwater high-speed propulsion.However,the effect of powder injection mode on its performance and the mechanism of this effect are not well understood.In this paper,a computational framework for multiphase combustion flow is developed and validated.Further,the effects of different injection schemes on flow combustion characteristics and engine performance are evaluated via simulation.Our findings indicate that the dominant recirculation zone in front of the primary water inlet delivers water vapor to the combustor head,providing the necessary oxidant for the ignition and combustion of Al particles.Changing the injection parameters directly affects the flame zone distribution and the ability of the recirculation zone to deliver water vapor,leading to variations in particle ignition delay.The engine combustion efficiency and specific impulse efficiency exhibit a negative correlation with injection height,peaking before declining with increased injection angle.It is shown that particle mixing degree and particle dispersion degree are closely related to engine performance.Enhanced particle mixing in front of the primary water inlet and particle dispersion behind the secondary water inlet are considered favorable approaches to improve engine performance,which promotes the particle combustion process and improves the heat-work conversion efficiency.展开更多
OBJECTIVE:To assess the clinical effectiveness and safety of Danshen injection(丹参注射液)following immunosuppressive therapy in primary nephrotic syndrome(PNS)with acute kidney injury(AKI)patients.METHODS:PNS with AK...OBJECTIVE:To assess the clinical effectiveness and safety of Danshen injection(丹参注射液)following immunosuppressive therapy in primary nephrotic syndrome(PNS)with acute kidney injury(AKI)patients.METHODS:PNS with AKI patients selected from nephrotic syndrome inpatients between 2012 and 2022 were divided into two groups according to the treatment regimen:the DS group who were treated with the Danshen injection and the SC group who received supportive care.Propensity score matching was used to balance the confounding factors between the two groups.The outcomes were complete and partial renal function recovery for effectiveness analysis and severe bleeding events for safety analysis.Kaplan-Meier curves and logrank tests were used to compare cumulative recovery rates.Outcome risks were assessed using Cox proportional hazard regression models.RESULTS:The study enrolled 441 patients with PNS and AKI from a population of 3873 inpatients with nephrotic syndrome.Among them,95 received Danshen injection,and 346 received supportive care.After propensity score matching,95 patients in the DS group and 285 patients in the SC group were analyzed.No significant difference was observed in the complete recovery rate for the DS group vs SC group(72.9%vs 65.1%,P=0.130)at 6 months.Compared with the SC group,the DS group was associated with a significantly higher partial recovery rate(71.0%vs 37.5%,P=0.011)at 6 months and all recovery rates(93.4%vs 79.1%,P=0.006)at 6 months.CONCLUSION:In this real-world retrospective study of PNS with AKI patients,Danshen injection following immunosuppressive therapy and prophylactic anticoagulation with low molecular heparin significantly increased 6-month partial renal function recovery and had a safety profile.Further randomized clinical trials are warranted to confirm the benefit of Danshen(Radix Salviae Miltiorrhizae)in these patients.展开更多
This paper presents the results of free-jet experiments conducted on an internal injection oblique detonation engine in a large-scale hypersonic shock tunnel.To overcome the challenges of non-uniform mixing and the fa...This paper presents the results of free-jet experiments conducted on an internal injection oblique detonation engine in a large-scale hypersonic shock tunnel.To overcome the challenges of non-uniform mixing and the failure of oblique detonation wave initiation when using liquid fuel,a combined strut-wall injection configuration was employed.Initiation was achieved by introducing a bump structure on the wedge.The results demonstrate that this strategy for mixing and initiation effectively establishes the oblique detonation wave combustion flow field.To further investigate the fuel mixing and initiation processes in the oblique detonation engine,three-dimensional numerical simulations consistent with the experimental conditions were carried out using the ReynoldsAveraged Navier-Stokes(RANS)method.The simulation results reveal that the high-speed gas flow generates shock waves as it passes through the central strut and transverse fuel jets.These shock waves are reflected by the wall,forming a series of shocks in the mixing section.The kerosene injected from the strut injectors does not react during the mixing phase.However,due to the influence of the high-temperature boundary layer,the kerosene injected through the wall undergoes precombustion.The separation zone upstream of the bump generates separation shock waves,allowing the multi-wave point to stabilize at a short distance from the leading edge of the wedge.展开更多
Objective:To explore the therapeutic effect of double-puncture tympanic membrane puncture and tympanic cavity drug injection in patients with acute secretory otitis media.Methods:A total of 84 patients with acute secr...Objective:To explore the therapeutic effect of double-puncture tympanic membrane puncture and tympanic cavity drug injection in patients with acute secretory otitis media.Methods:A total of 84 patients with acute secretory otitis media admitted to our hospital from June 2024 to June 2025 were selected and randomly divided into two groups by drawing lots.The control group(42 cases)was treated with the traditional single-puncture tympanic membrane puncture and tympanic cavity drug injection method,while the observation group(42 cases)was treated with the double-puncture tympanic membrane puncture and tympanic cavity drug injection method.The therapeutic effects of the two groups were compared.Results:The overall treatment response rate,overall complication rate,time to symptom relief,and improvement in hearing threshold in the observation group were all superior to those in the control group,with statistically significant differences(P<0.05).Conclusion:For acute secretory otitis media,the treatment method of double-puncture tympanic membrane puncture and tympanic cavity drug injection demonstrates definite efficacy,significantly reducing the incidence of complications,accelerating symptom relief,and improving hearing function,making it worthy of promotion.展开更多
Objective:To investigate the impact of anti-Müllerian hormone(AMH)levels on the outcomes of intracytoplasmic sperm injection(ICSI)cycles in women of advanced age and also to explore the effect of age on the ICSI ...Objective:To investigate the impact of anti-Müllerian hormone(AMH)levels on the outcomes of intracytoplasmic sperm injection(ICSI)cycles in women of advanced age and also to explore the effect of age on the ICSI results in patients with low AMH levels.Methods:This retrospective cohort study involved 143 infertile couples undergoing ICSI cycles at a fertility clinic in Iran from November 2021 to November 2023.Women aged<37 years with AMH<1 ng/mL and those aged≥37 years were included.A standardized ovarian stimulation protocol was followed,leading to oocyte retrieval and ICSI on mature oocytes.Key oocyte quality indexes,including the maturation rate,fertilization rate,and embryo quality metrics,were evaluated.Poisson regression analyses were also employed to investigate the association between AMH levels and oocyte quality parameters in the advanced age groups,as well as the association between age and oocyte quality parameters in patients with low AMH.Results:We analyzed 143 ICSI cycles from 143 infertile couples.The mean ages of the women and their partners were(38.2±4.7)years and(40.6±5.9)years,respectively,with a median(IQR)AMH level of 0.7(0.4–2.0)ng/mL.Younger women with low AMH levels(<1 ng/mL)showed significantly better outcomes in terms of the number of MⅡ oocytes[adjusted odds ratio(aOR)1.89,95%CI 1.31-2.71;P=0.001],fertilized(2PN)oocytes(aOR 1.97,95%CI 1.36-2.86;P<0.001),embryo number(aOR 2.16,95%CI 1.44-3.24;P<0.001),and embryos suitable for freezing(aOR 2.88,95%CI 1.80-4.61;P<0.001)compared to advanced-age women.Furthermore,among women of advanced age,those with normal AMH levels exhibited a significantly higher number of MⅡ oocyte(aOR 3.55,95%CI 2.31-5.44;P<0.001),fertilized(2PN)oocytes(aOR 3.54,95%CI 2.29-5.49;P<0.001),embryo number(aOR 3.89,95%CI 2.48-6.10;P<0.001),and embryos suitable for freezing(aOR 4.75,95%CI 2.79-8.09;P<0.001)compared to those with low AMH levels.Conclusions:AMH level is a significant predictor of oocyte and embryo number and quality in infertile women of advanced age undergoing ICSI cycles.Our findings suggest that maternal age markedly impacts the quality of oocytes and embryos in low AMHlevel patients.展开更多
The increasing integration of cyber-physical components in Industry 4.0 water infrastructures has heightened the risk of false data injection(FDI)attacks,posing critical threats to operational integrity,resource manag...The increasing integration of cyber-physical components in Industry 4.0 water infrastructures has heightened the risk of false data injection(FDI)attacks,posing critical threats to operational integrity,resource management,and public safety.Traditional detection mechanisms often struggle to generalize across heterogeneous environments or adapt to sophisticated,stealthy threats.To address these challenges,we propose a novel evolutionary optimized transformer-based deep reinforcement learning framework(Evo-Transformer-DRL)designed for robust and adaptive FDI detection in smart water infrastructures.The proposed architecture integrates three powerful paradigms:a transformer encoder for modeling complex temporal dependencies in multivariate time series,a DRL agent for learning optimal decision policies in dynamic environments,and an evolutionary optimizer to fine-tune model hyper-parameters.This synergy enhances detection performance while maintaining adaptability across varying data distributions.Specifically,hyper-parameters of both the transformer and DRL modules are optimized using an improved grey wolf optimizer(IGWO),ensuring a balanced trade-off between detection accuracy and computational efficiency.The model is trained and evaluated on three realistic Industry 4.0 water datasets:secure water treatment(SWaT),water distribution(WADI),and battle of the attack detection algorithms(BATADAL),which capture diverse attack scenarios in smart treatment and distribution systems.Comparative analysis against state-of-the-art baselines including Transformer,DRL,bidirectional encoder representations from transformers(BERT),convolutional neural network(CNN),long short-term memory(LSTM),and support vector machines(SVM)demonstrates that our proposed Evo-Transformer-DRL framework consistently outperforms others in key metrics such as accuracy,recall,area under the curve(AUC),and execution time.Notably,it achieves a maximum detection accuracy of 99.19%,highlighting its strong generalization capability across different testbeds.These results confirm the suitability of our hybrid framework for real-world Industry 4.0 deployment,where rapid adaptation,scalability,and reliability are paramount for securing critical infrastructure systems.展开更多
In this paper,an investigation is made to study the effects of radiation and heat source/sink on the unsteady boundary layerflow and heat transfer past a shrinking sheet with suction/injection.Theflow is permeated by an...In this paper,an investigation is made to study the effects of radiation and heat source/sink on the unsteady boundary layerflow and heat transfer past a shrinking sheet with suction/injection.Theflow is permeated by an externally applied magneticfield normal to the plane offlow.The self-similar equations correspond-ing to the velocity and temperaturefields are obtained,and then solved numerically byfinite difference method using quasilinearization technique.The study reveals that the momentum boundary layer thickness increases with increasing unsteadiness and decreases with magneticfield.The thermal boundary layer thickness decreases with Prandtl number,radiation parameter and heat sink parameter,but it increases with heat source parameter.Moreover,increasing unsteadiness,magneticfield strength,radiation and heat sink strength boost the heat transfer.展开更多
The present study reveals the effect of nonlinear thermal radiation and magnetic field on a boundary layer flow of a viscous fluid over a nonlinear stretching sheet with suction or an injection. Using suitable similar...The present study reveals the effect of nonlinear thermal radiation and magnetic field on a boundary layer flow of a viscous fluid over a nonlinear stretching sheet with suction or an injection. Using suitable similarity transformations, governing partial differential equations were reduced to higher order ordinary differential equations and further these are solved numerically using of Keller-Box method. Effect of flow controlling parameter on velocity, temperature and nanoparticle fluid concentration, local skin friction coefficient, local Nusselt number and local Sherwood numbers are discussed. It is found that the dimensionless velocity decreases and temperature, concentration are increased with the increasing of magnetic parameter. The temperature profile is an increasing function of thermal radiation when it is increasing.展开更多
The magnetohydrodynamic(MHD)boundary layer slipflow and solute transfer over a porous plate in the presence of a chemical reaction are investigated.The governing equations were transformed into self-similar ordinary di...The magnetohydrodynamic(MHD)boundary layer slipflow and solute transfer over a porous plate in the presence of a chemical reaction are investigated.The governing equations were transformed into self-similar ordinary differential equations by adopting the similarity transformation technique.Then the numerical solutions are obtained by a shooting technique using the fourth order Runge-Kutta method.The study reveals that due to the increase in the boundary slip,the concentration decreases and the velocity increases.On the other hand,with an increase in the magneticfield and mass suction,both boundary layer thicknesses decreased.As the Schmidt number and the reaction rate parameter increases,the concentration decreases and the mass transfer increases.展开更多
Combined heat and mass transfer on free, forced, and mixed convection flow along a porous wedge with magnetic effect in the presence of chemical reaction is investigated. The flow field characteristics are analyzed by...Combined heat and mass transfer on free, forced, and mixed convection flow along a porous wedge with magnetic effect in the presence of chemical reaction is investigated. The flow field characteristics are analyzed by the Runge-Kutta-Gill scheme with the shooting method as well as the local non-similarity method up to the third level of truncation, which are used to reduce the governing partial differential equations into nine ordinary differential equations. The governing boundary layer equations are converted to a dimensionless form by Falkner-Skan transformations. Because of the effect of suction/injection on the wall of the wedge with buoyancy force and variable wall temperature, the flow field is locally non-similar. Numerical calculations up to the third order level of truncation are carried out as a special case for different values of dimensionless parameters. Effects of the magnetic field strength in the presence of chemical reaction with variable wall temperature and concentration on the dimensionless velocity, temperature and concentration profiles are shown graphically.展开更多
An analysis is performed to study the heat transfer characteristics of steady two-dimensional boundary layer flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the ...An analysis is performed to study the heat transfer characteristics of steady two-dimensional boundary layer flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the flow field and heat transfer characteristics are numerically studied by using an implicit finite difference method. It is found that dual solutions exist when the plate and the free stream move in the opposite directions. The results indicate that suction delays the boundary layer separation, while injection accelerates it.展开更多
文摘Characteristics of heat transfer and flow of Newtonian and non-Newtonian fluids through porous walls and in porous media are studied due to their wide range of applications including geothermal reservoirs,heat exchangers,marine propulsion,and aerodynamics.The current study investigates the characteristics of heat transport in a reactive third-grade fluid,moving through permeable parallel plates,with uniform suction/injection velocity.The two permeable,parallel plates are maintained at the same,constant temperature.After being transformed into its dimensionless equivalent,governing equations are solved by employing the Least Squares Method(LSM).The LSM results are further validated with numerical solutions for temperature and velocity.The impact of cross-flow Reynolds number,Peclet number,heat generation parameter,non-Newtonian parameter,and Brinkman number on entropy generation,velocity,temperature,and Bejan number are investigated.Theresults indicate that temperature distribution is significantly influenced by the third-grade fluid parameter.The maximum temperature drops from almost 0.12 to 0.10 as the third-grade fluid parameter increases from0.05 to 0.4.When the cross-flow Reynolds number is raised from 0.05 to 3,the maximum temperature drops from 0.12 to around 0.09.Temperature is strongly influenced by the heat generation parameter.A greater understanding of the thermal characteristics necessary for the design of a variety of systems,such as heat exchangers,marine propulsion,aerodynamic systems,etc.,may be gained from the findings of the current study.
基金the Deanship of Scientific Research,Taif University,KSA[Research Project Number 0-440-6166].
文摘This paper introduces the effect of heat absorption(generation)and suction(injection)on magnetohydrodynamic(MHD)boundary-layer flow of Casson nanofluid(CNF)via a non-linear stretching surface with the viscous dissipation in two dimensions.By utilizing the similarity transformations,the leading PDEs are transformed into a set of ODEs with adequate boundary conditions and then resolved numerically by(4–5)^(th)-order Runge-Kutta Fehlberg procedure based on the shooting technique.Numerical computations are carried out by Maple 15 software.With the support of graphs,the impact of dimensionless control parameters on the nanoparticle concentration profiles,the temperature,and the flow velocity are studied.Other parameters of interest,such as the skin friction coefficient,heat,and mass transport at the diverse situation and dependency of various parameters are inspected through tables and graphs.Additionally,it is verified that the numerical computations with the reported earlier studies are in an excellent approval.It is found that the heat and mass transmit rates are enhanced with the increasing values of the power-index and the suction(blowing)parameter,whilst are reduced with the boosting Casson and the heat absorption(generation)parameters.Also,the drag force coefficient is an increasing function of the powerindex and a reduction function of Casson parameter.
文摘Several new techniques in the field of heat transfer in fluids have opened new avenues for studying the heat transfer effects in nanofluids and thermodynamic flow parameters, leading to novel applications. There have been studies on nanofluids, including metal, ceramic and magnetic nanoparticles mixed with base fluids such as Water, Kerosene, and Ethylene glycol. However, research on fluids employing semiconductor nanoparticles as supplements to base fluids to generate nanofluids and hybrid nanofluids is limited. For the investigation, Gallium nitrite, a binary semiconductor with excellent heat convection, is together with Cu metal nanoparticles and Al<sub>2</sub>O<sub>3</sub> ceramic nanoparticles separately in the base fluid Ethylene glycol (EG) to form hybrid nanofluids. The effects of convective boundary conditions, thermal radiation, heat source/sink, suction/injection, and activation energy on three-dimensional Williamson MHD hybrid nanofluid flow of Cu + GaN + EG, Al<sub>2</sub>O<sub>3</sub> + GaN + EG, and Cu + Al<sub>2</sub>O<sub>3</sub> + EG are investigated on a stretched sheet with porosity. A similarity transformation is performed on the governing equations to transform them into dimensionless ordinary differential equations ODEs. Numerical analysis is carried out in MATLAB utilizing bvp5c and the shooting technique. The variations of velocity, temperature, and concentration profiles as a function of different physical effects are presented graphically with dimensionless parameters and explained the variations scientifically. As varied with different parameters, the values of the Skin-friction coefficient, Nusselt number, and Sherwood number are mentioned in the table.
文摘The aim of this work is to study the effect of non-uniform single and double slot suction/injection into a steady mixed convection boundary layer flow over a vertical cone, while the axis of the cone is inline with the flow. The governing boundary layer equations are transformed into a non-dimensional form by a group of non-similar trans- formations. The resulting coupled non-linear partial differential equations are solved nu- merically by employing the quasi-linearization technique and an implicit finite-difference scheme. Numerical computations are performed for different values of the dimensionless parameters to display the velocity and temperature profiles graphically. Also, numerical results are presented for the skin friction and heat transfer coefficients. Results indicate that the skin friction and heat transfer coefficients increase with non-uniform slot suction, but the effect of non-uniform slot injection is just opposite.
文摘The work presented herein investigates the velocity, heat transfer, Nusselt number and skin friction profiles involved in boundary layer flow past a moving vertical porous plate. Similarity transformations are employed to convert the governing nonlinear unsteady momentum and energy equations from their partial differential equation forms to boundary value ordinary differential equations. The resulting equations are then solved numerically by the Runge-Kutta fourth order method with the help of a shooting technique. Several features of the flow and heat transfer characteristics for different values of problem parameters are analyzed and discussed. These include the effects of the radiation parameter (R), suction and injection parameter (c), Grashof (Gr) and Prandtl (Pr) numbers on the flow and heat profiles. Numerical results show the impact of blowing and sucking as well as radation on boundary layer flows of this type. Both the skin frictions as well as the heat transfer rate are also significantly related to the radiation parameter. For all these cases;the numerical results are found to be in agreement with the physics of the problem.
文摘Heat and mass transfer in vertical porous microchannels plays a crucial role in the design of micro heat exchangers and the cooling of micromechanical and microelectronic systems.When electroosmotic and electromagnetohydrodynamic(EO-EMHD)effects are incorporated,these channels enable active flow manipulation,mixing,and thermal regulation in Lab-on-a-Chip(LOC)devices,thereby broadening the scope of microscale cooling applications.This study investigates the effect of wall suction/injection on unsteady EMHD natural convection flow in a vertical microchannel,accounting for heat and mass transfer mechanisms.The dimensionless governing equations were formulated and solved analytically using appropriate initial and boundary conditions.Due to the coupled nature of the Soret and Dufour effects,a perturbation approach was employed to decouple the governing equations,which were then transformed from partial differential equations(PDEs)into ordinary differential equations(ODEs)using the Laplace Transform technique.Analytical expressions for velocity,temperature,and concentration were obtained in the Laplace domain,along with derived quantities such as skin friction,Nusselt number,and Sherwood number,evaluated through the Riemann-sum approximation.A MATLAB program was developed to examine the effects of key parameters including thermal radiation,Soret number,Dufour number,Grashof number,modified Grashof number,electric field strengths in the x and z directions,and the Hartmann number on the transport characteristics under suction and injection conditions.The results reveal that increasing the radiation parameter enhances the temperature and velocity but decreases the concentration.Similarly,higher E_(z),Gr,and Gm values lead to higher velocities,while increases in E_(x) and M suppress fluid motion.The findings provide physical insight into electro-magnetically driven convective transport in microchannels,highlighting the influence of cross-diffusion,radiation,and field effects on flow and thermal performance,offering valuable guidance for the design and optimization of Lab-on-a-Chip cooling systems.
基金supported by 2023 Higher Education Scientific Research Planning Project of China Society of Higher Education(No.23PG0408)2023 Philosophy and Social Science Research Programs in Jiangsu Province(No.2023SJSZ0993)+2 种基金Nantong Science and Technology Project(No.JC2023070)Key Project of Jiangsu Province Education Science 14th Five-Year Plan(Grant No.B-b/2024/02/41)the Open Fund of Advanced Cryptography and System Security Key Laboratory of Sichuan Province(Grant No.SKLACSS-202407).
文摘Large language models(LLMs)have revolutionized AI applications across diverse domains.However,their widespread deployment has introduced critical security vulnerabilities,particularly prompt injection attacks that manipulate model behavior through malicious instructions.Following Kitchenham’s guidelines,this systematic review synthesizes 128 peer-reviewed studies from 2022 to 2025 to provide a unified understanding of this rapidly evolving threat landscape.Our findings reveal a swift progression from simple direct injections to sophisticated multimodal attacks,achieving over 90%success rates against unprotected systems.In response,defense mechanisms show varying effectiveness:input preprocessing achieves 60%–80%detection rates and advanced architectural defenses demonstrate up to 95%protection against known patterns,though significant gaps persist against novel attack vectors.We identified 37 distinct defense approaches across three categories,but standardized evaluation frameworks remain limited.Our analysis attributes these vulnerabilities to fundamental LLM architectural limitations,such as the inability to distinguish instructions from data and attention mechanism vulnerabilities.This highlights critical research directions such as formal verification methods,standardized evaluation protocols,and architectural innovations for inherently secure LLM designs.
文摘Background:Penile augmentation through injectable substances is becoming increasingly common.A growing number of aesthetic clinics are developing penile enlargement procedures using various injectable materials.Although these procedures are now performed in more controlled and medically supervised environments,their long-term outcomes remain poorly understood.The promotion of such medical treatments contributes to an increasing interest among adult males in self-injection as a method to alleviate psychological distress associated with penile size concerns.At the same time,access to injectable substances through unofficial or unregulated sources has become increasingly easy.Tor our knowledge,we report the first documented case of self-injection with Garamycin®(gentamicin)cream,contributing to the literature on the often multidisciplinary management of penile enlargement injections,a field still lacking well-established guidelines.Case Description:This case report describes a young patient who self-injected Garamycin®into the penis for the purpose of enlargement.He presented to our urology department with worsening symptoms,including severe and poorly tolerated pain.His primary request was prompt relief of pain while preserving,as much as possible,the aesthetic appearance and functional integrity of his penis.This case required a multi-stage surgical approach to salvage the penis and preserve both its structural integrity and functional outcome.Conclusions:To our knowledge,this case report documents the first reported instance of Garamycin®injection performed for the purpose of penile enlargement.It provides insight into the clinical course of such penile cream injections,demonstrates that a two-stage scrotal flap can achieve both functional and aesthetic outcomes,and highlights the importance of comprehensive management particularly addressing the traumatic impact of penile deformity secondary to inflammation and/or infection,as well as the body dysmorphic concerns often associated with these cases.
基金supported by JSPS KAKENHI Grant Numbers JP23K28377,JP24H00714,JP25K15109,JP25K03190,JP25K03232,JP22K12157The Telecommunications Advancement Foundation.
文摘While Large Language Models(LLMs)possess the capability to perform a wide range of tasks,security attacks known as prompt injection and jailbreaking remain critical challenges.Existing defense approaches addressing this problem face challenges such as the over-refusal of prompts that contain harmful vocabulary but are semantically benign,and the limited accuracy improvement inmachine learning-based approaches due to the ease of distinguishing benign prompts in existing datasets.Therefore,we propose a multi-LLM agent framework aimed at achieving both the accurate rejection of harmful prompts and appropriate responses to benign prompts.Distinct from prior studies,the proposed method adopts In-Context Learning(ICL)during the learning phase,presenting a novel approach that obviates the need for computationally expensive parameter updates required by conventional fine-tuning.To demonstrate the proposed method’s capability for rapid and easy deployment,this study targets LLMs with insufficient alignment.In the experiments,macro-averaged binary classification metrics were used to comprehensively evaluate harmfulness detection.Experimental results using three LLMs demonstrated that the proposed method achieved performance that surpassed four baselines across all evaluation metrics for the target LLMs,evidencing significant effectiveness with an average improvement of 16.6 points in F1-score compared to the vanilla models.The significance of this study lies in the proposal of a novel approach based on ICL that does not require parameter updates.This framework offers high sustainability in practical deployment,as it allows for the adaptive enhancement of detection performance against continuously evolving attack methods solely through the accumulation of logs,without the necessity of retraining the LLM itself.By mitigating the trade-off between safety and utility,this research contributes to the implementation of robust LLMs.
基金supported by the National Natural Science Foundation of China(No.22305053)the Fundamental Research Funds for the Central Universities,China(No.3072024WD0201)。
文摘Powder-Fueled Water Ramjet Engine(PFWRE)is the most promising powerplant in underwater high-speed propulsion.However,the effect of powder injection mode on its performance and the mechanism of this effect are not well understood.In this paper,a computational framework for multiphase combustion flow is developed and validated.Further,the effects of different injection schemes on flow combustion characteristics and engine performance are evaluated via simulation.Our findings indicate that the dominant recirculation zone in front of the primary water inlet delivers water vapor to the combustor head,providing the necessary oxidant for the ignition and combustion of Al particles.Changing the injection parameters directly affects the flame zone distribution and the ability of the recirculation zone to deliver water vapor,leading to variations in particle ignition delay.The engine combustion efficiency and specific impulse efficiency exhibit a negative correlation with injection height,peaking before declining with increased injection angle.It is shown that particle mixing degree and particle dispersion degree are closely related to engine performance.Enhanced particle mixing in front of the primary water inlet and particle dispersion behind the secondary water inlet are considered favorable approaches to improve engine performance,which promotes the particle combustion process and improves the heat-work conversion efficiency.
基金Supported by Key Project of Science and Technology Program Coconstructed by the Science and Technology Department of the National Administration of Traditional Chinese Medicine of China and Administration of Traditional Chinese Medicine of Zhejiang Province:A Study on the Efficacy and Safety of Danshen(Radix Salviae Miltiorrhizae)in Treating Acute Kidney Injury in Patients with Primary Nephrotic Syndrome(GZY-ZJ-KJ-23085)Basic Research Project of Wenzhou Science and Technology Bureau:the Mechanism of Hypoxia Induicible Factor-1 alpha Down-regulating Angiotensinconverting Enzyme 2 in Proximal Renal Tubular Epithelial Cells Leading to Brush Border Shedding in Early Acute Kidney Injury Induced by Sepsis(Y20240071)。
文摘OBJECTIVE:To assess the clinical effectiveness and safety of Danshen injection(丹参注射液)following immunosuppressive therapy in primary nephrotic syndrome(PNS)with acute kidney injury(AKI)patients.METHODS:PNS with AKI patients selected from nephrotic syndrome inpatients between 2012 and 2022 were divided into two groups according to the treatment regimen:the DS group who were treated with the Danshen injection and the SC group who received supportive care.Propensity score matching was used to balance the confounding factors between the two groups.The outcomes were complete and partial renal function recovery for effectiveness analysis and severe bleeding events for safety analysis.Kaplan-Meier curves and logrank tests were used to compare cumulative recovery rates.Outcome risks were assessed using Cox proportional hazard regression models.RESULTS:The study enrolled 441 patients with PNS and AKI from a population of 3873 inpatients with nephrotic syndrome.Among them,95 received Danshen injection,and 346 received supportive care.After propensity score matching,95 patients in the DS group and 285 patients in the SC group were analyzed.No significant difference was observed in the complete recovery rate for the DS group vs SC group(72.9%vs 65.1%,P=0.130)at 6 months.Compared with the SC group,the DS group was associated with a significantly higher partial recovery rate(71.0%vs 37.5%,P=0.011)at 6 months and all recovery rates(93.4%vs 79.1%,P=0.006)at 6 months.CONCLUSION:In this real-world retrospective study of PNS with AKI patients,Danshen injection following immunosuppressive therapy and prophylactic anticoagulation with low molecular heparin significantly increased 6-month partial renal function recovery and had a safety profile.Further randomized clinical trials are warranted to confirm the benefit of Danshen(Radix Salviae Miltiorrhizae)in these patients.
基金National Natural Science Foundation of China(No.52006181)。
文摘This paper presents the results of free-jet experiments conducted on an internal injection oblique detonation engine in a large-scale hypersonic shock tunnel.To overcome the challenges of non-uniform mixing and the failure of oblique detonation wave initiation when using liquid fuel,a combined strut-wall injection configuration was employed.Initiation was achieved by introducing a bump structure on the wedge.The results demonstrate that this strategy for mixing and initiation effectively establishes the oblique detonation wave combustion flow field.To further investigate the fuel mixing and initiation processes in the oblique detonation engine,three-dimensional numerical simulations consistent with the experimental conditions were carried out using the ReynoldsAveraged Navier-Stokes(RANS)method.The simulation results reveal that the high-speed gas flow generates shock waves as it passes through the central strut and transverse fuel jets.These shock waves are reflected by the wall,forming a series of shocks in the mixing section.The kerosene injected from the strut injectors does not react during the mixing phase.However,due to the influence of the high-temperature boundary layer,the kerosene injected through the wall undergoes precombustion.The separation zone upstream of the bump generates separation shock waves,allowing the multi-wave point to stabilize at a short distance from the leading edge of the wedge.
文摘Objective:To explore the therapeutic effect of double-puncture tympanic membrane puncture and tympanic cavity drug injection in patients with acute secretory otitis media.Methods:A total of 84 patients with acute secretory otitis media admitted to our hospital from June 2024 to June 2025 were selected and randomly divided into two groups by drawing lots.The control group(42 cases)was treated with the traditional single-puncture tympanic membrane puncture and tympanic cavity drug injection method,while the observation group(42 cases)was treated with the double-puncture tympanic membrane puncture and tympanic cavity drug injection method.The therapeutic effects of the two groups were compared.Results:The overall treatment response rate,overall complication rate,time to symptom relief,and improvement in hearing threshold in the observation group were all superior to those in the control group,with statistically significant differences(P<0.05).Conclusion:For acute secretory otitis media,the treatment method of double-puncture tympanic membrane puncture and tympanic cavity drug injection demonstrates definite efficacy,significantly reducing the incidence of complications,accelerating symptom relief,and improving hearing function,making it worthy of promotion.
文摘Objective:To investigate the impact of anti-Müllerian hormone(AMH)levels on the outcomes of intracytoplasmic sperm injection(ICSI)cycles in women of advanced age and also to explore the effect of age on the ICSI results in patients with low AMH levels.Methods:This retrospective cohort study involved 143 infertile couples undergoing ICSI cycles at a fertility clinic in Iran from November 2021 to November 2023.Women aged<37 years with AMH<1 ng/mL and those aged≥37 years were included.A standardized ovarian stimulation protocol was followed,leading to oocyte retrieval and ICSI on mature oocytes.Key oocyte quality indexes,including the maturation rate,fertilization rate,and embryo quality metrics,were evaluated.Poisson regression analyses were also employed to investigate the association between AMH levels and oocyte quality parameters in the advanced age groups,as well as the association between age and oocyte quality parameters in patients with low AMH.Results:We analyzed 143 ICSI cycles from 143 infertile couples.The mean ages of the women and their partners were(38.2±4.7)years and(40.6±5.9)years,respectively,with a median(IQR)AMH level of 0.7(0.4–2.0)ng/mL.Younger women with low AMH levels(<1 ng/mL)showed significantly better outcomes in terms of the number of MⅡ oocytes[adjusted odds ratio(aOR)1.89,95%CI 1.31-2.71;P=0.001],fertilized(2PN)oocytes(aOR 1.97,95%CI 1.36-2.86;P<0.001),embryo number(aOR 2.16,95%CI 1.44-3.24;P<0.001),and embryos suitable for freezing(aOR 2.88,95%CI 1.80-4.61;P<0.001)compared to advanced-age women.Furthermore,among women of advanced age,those with normal AMH levels exhibited a significantly higher number of MⅡ oocyte(aOR 3.55,95%CI 2.31-5.44;P<0.001),fertilized(2PN)oocytes(aOR 3.54,95%CI 2.29-5.49;P<0.001),embryo number(aOR 3.89,95%CI 2.48-6.10;P<0.001),and embryos suitable for freezing(aOR 4.75,95%CI 2.79-8.09;P<0.001)compared to those with low AMH levels.Conclusions:AMH level is a significant predictor of oocyte and embryo number and quality in infertile women of advanced age undergoing ICSI cycles.Our findings suggest that maternal age markedly impacts the quality of oocytes and embryos in low AMHlevel patients.
文摘The increasing integration of cyber-physical components in Industry 4.0 water infrastructures has heightened the risk of false data injection(FDI)attacks,posing critical threats to operational integrity,resource management,and public safety.Traditional detection mechanisms often struggle to generalize across heterogeneous environments or adapt to sophisticated,stealthy threats.To address these challenges,we propose a novel evolutionary optimized transformer-based deep reinforcement learning framework(Evo-Transformer-DRL)designed for robust and adaptive FDI detection in smart water infrastructures.The proposed architecture integrates three powerful paradigms:a transformer encoder for modeling complex temporal dependencies in multivariate time series,a DRL agent for learning optimal decision policies in dynamic environments,and an evolutionary optimizer to fine-tune model hyper-parameters.This synergy enhances detection performance while maintaining adaptability across varying data distributions.Specifically,hyper-parameters of both the transformer and DRL modules are optimized using an improved grey wolf optimizer(IGWO),ensuring a balanced trade-off between detection accuracy and computational efficiency.The model is trained and evaluated on three realistic Industry 4.0 water datasets:secure water treatment(SWaT),water distribution(WADI),and battle of the attack detection algorithms(BATADAL),which capture diverse attack scenarios in smart treatment and distribution systems.Comparative analysis against state-of-the-art baselines including Transformer,DRL,bidirectional encoder representations from transformers(BERT),convolutional neural network(CNN),long short-term memory(LSTM),and support vector machines(SVM)demonstrates that our proposed Evo-Transformer-DRL framework consistently outperforms others in key metrics such as accuracy,recall,area under the curve(AUC),and execution time.Notably,it achieves a maximum detection accuracy of 99.19%,highlighting its strong generalization capability across different testbeds.These results confirm the suitability of our hybrid framework for real-world Industry 4.0 deployment,where rapid adaptation,scalability,and reliability are paramount for securing critical infrastructure systems.
基金the financial support of National Board for Higher Mathematics(NBHM),DAE,Mumbai,India for pursuing this work.
文摘In this paper,an investigation is made to study the effects of radiation and heat source/sink on the unsteady boundary layerflow and heat transfer past a shrinking sheet with suction/injection.Theflow is permeated by an externally applied magneticfield normal to the plane offlow.The self-similar equations correspond-ing to the velocity and temperaturefields are obtained,and then solved numerically byfinite difference method using quasilinearization technique.The study reveals that the momentum boundary layer thickness increases with increasing unsteadiness and decreases with magneticfield.The thermal boundary layer thickness decreases with Prandtl number,radiation parameter and heat sink parameter,but it increases with heat source parameter.Moreover,increasing unsteadiness,magneticfield strength,radiation and heat sink strength boost the heat transfer.
文摘The present study reveals the effect of nonlinear thermal radiation and magnetic field on a boundary layer flow of a viscous fluid over a nonlinear stretching sheet with suction or an injection. Using suitable similarity transformations, governing partial differential equations were reduced to higher order ordinary differential equations and further these are solved numerically using of Keller-Box method. Effect of flow controlling parameter on velocity, temperature and nanoparticle fluid concentration, local skin friction coefficient, local Nusselt number and local Sherwood numbers are discussed. It is found that the dimensionless velocity decreases and temperature, concentration are increased with the increasing of magnetic parameter. The temperature profile is an increasing function of thermal radiation when it is increasing.
基金gratefully acknowledges the financial support from the National Board for Higher Mathematics(NBHM),DAE,Mumbai,India to pursue this work.
文摘The magnetohydrodynamic(MHD)boundary layer slipflow and solute transfer over a porous plate in the presence of a chemical reaction are investigated.The governing equations were transformed into self-similar ordinary differential equations by adopting the similarity transformation technique.Then the numerical solutions are obtained by a shooting technique using the fourth order Runge-Kutta method.The study reveals that due to the increase in the boundary slip,the concentration decreases and the velocity increases.On the other hand,with an increase in the magneticfield and mass suction,both boundary layer thicknesses decreased.As the Schmidt number and the reaction rate parameter increases,the concentration decreases and the mass transfer increases.
文摘Combined heat and mass transfer on free, forced, and mixed convection flow along a porous wedge with magnetic effect in the presence of chemical reaction is investigated. The flow field characteristics are analyzed by the Runge-Kutta-Gill scheme with the shooting method as well as the local non-similarity method up to the third level of truncation, which are used to reduce the governing partial differential equations into nine ordinary differential equations. The governing boundary layer equations are converted to a dimensionless form by Falkner-Skan transformations. Because of the effect of suction/injection on the wall of the wedge with buoyancy force and variable wall temperature, the flow field is locally non-similar. Numerical calculations up to the third order level of truncation are carried out as a special case for different values of dimensionless parameters. Effects of the magnetic field strength in the presence of chemical reaction with variable wall temperature and concentration on the dimensionless velocity, temperature and concentration profiles are shown graphically.
基金supported by a research grant from the Universiti Kebangsaan Malaysia (Project Code: UKM-GGPM-NBT-080-2010)
文摘An analysis is performed to study the heat transfer characteristics of steady two-dimensional boundary layer flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the flow field and heat transfer characteristics are numerically studied by using an implicit finite difference method. It is found that dual solutions exist when the plate and the free stream move in the opposite directions. The results indicate that suction delays the boundary layer separation, while injection accelerates it.
