Radiation Impacts Research Articles

Chemical Reaction, Thermal Radiation and Newtonian Heating Impacts on Unsteady MHD Rotating Casson Fluid Flow Past an Infinite Vertical Porous Surface

Chemical Reaction, Thermal Radiation and Newtonian Heating Impacts on Unsteady MHD Rotating Casson Fluid Flow Past an Infinite Vertical Porous Surface

Numerical method of radiation impact on unsteady MHD nanofluid flow past an accelerated vertical porous plate with heat source

ABSTRACT This present research is focused on unsteady MHD (Magnetohydrodynamics) nanofluid flow past a vertically accelerated plate through a porous medium in the existence of heat source and radiation impacts. All three ingredients are thought to be nanofluids based on water that can conduct electricity. The effects of electromagnetic fields and radiation are considered. The numerical explanations of the governing equations are achieved using the finite difference method. Graphical demonstrations of the temperature and velocity fields of Ag-water and Ti O 2 -water are shown. Ag-water has higher velocities than Ti O 2 -water. Ag-water has a higher temperature than Ti O 2 -water. When the magnetic force is kept the same between the plate and the fluid, the velocity curves are found to be a lot higher than when it is kept the same between the plate and the fluid.

Hydromagnetic flow of Casson nano-fluid across a stretched sheet in the presence of thermoelectric and radiation

This work revealed the investigation of the Casson nanofluid flow's MHD (magneto-hydrodynamic) unstable boundary layer characteristics in the simultaneous transmission of thermoelectric and radiation on a stretched sheet. On MHD Newtonian and non-Newtonian (Casson) nanofluid flows, the cumulative impact of radiation and thermoelectricity has been addressed. Thermal radiation, Casson nanofluids, and MHD are pivotal in engineering and industry, transforming applications like heat exchangers, nuclear power plants, thermal energy storage, and advanced drug delivery systems. The problem-related partial differential equations have been formulated with boundary layer approximation. The boundary layer equations have been changed into dimensionless form with the help of appropriate dimensionless variables and parameters. Finite difference techniques have been employed to get the numerical solution via the FORTRAN 6.6a programming algorithm, and the numerical solutions have been illustrated graphically with the support of Tecplot-360 software. The consequences of the numerous parameters have been investigated using a variety of figures, with the amounts of the various parameters being revised. The simultaneous effects of thermoelectric and radiation on primary velocity, secondary velocity, and temperature profiles have been presented and discussed with critical physical properties such as skin friction in addition to Nusselt number. The combined effects of thermoelectric and radiation on streamlines and isotherms have been illustrated with line and contour flood views. The most significant finding is that the collective influence of thermoelectric and thermal radiation impacts promotes the physical phenomena of non-Newtonian (Casson) fluid flow comparatively more than Newtonian fluid flow. For the purpose of creating effective procedures, forecasting flow patterns, and guaranteeing product performance in a variety of industries, it is crucial to explain the Casson fluids. This model can also aid in blood flow simulation and risk assessment for thrombosis and other cardiovascular diseases.

Nuclear reactor application on Jeffrey fluid flow with Falkner-skan factor, Brownian and thermophoresis, non linear thermal radiation impacts past a wedge

In this paper, an impact of non-linear thermal radiation, Brownian and thermophoresis on an MHD through a wedge with dissipative impacts for Jeffrey fluid is investigated. In addition, heat transport analysis is carried out. This work's originality is attributable to the Jeffrey fluid formulation, nonlinear thermal radiation, Brownian and Thermophoresis. The boundary layer approximations are examined, to transform the governing equations into partial differential equations. Utilizing appropriate similarity transformations, the boundary value issue is expressed in ordinary differential form. BVP4C, a nonlinear numerical method, was utilized to determine the outcomes of velocity, concentration and temperature fields at multiple points of the measured quantities. The skin friction term, Sherwood and Nusselt numbers were analyzed in depth, and the findings are achieved graphically and tabularly. A comparison via the previously published data reveals a good degree of concordance. This research focuses mostly on the modelling of flow in a nuclear reactor. The boundary layer flow caused by a wedge surface play s a crucial role the aspects of geothermal and heat exchangers systems.

Mathematical Study of MHD Micropolar Fluid Flow with Radiation and Dissipative Impacts over a Permeable Stretching Sheet: Slip Effects Phenomena

Mathematical Study of MHD Micropolar Fluid Flow with Radiation and Dissipative Impacts over a Permeable Stretching Sheet: Slip Effects Phenomena

Mathematical Modeling of MHD Flow of CNTs/Ag Nanoparticles Past a Heated Stretchy Surface with Nonuniform Heat Sink/Source and Thermal Radiation Impacts

This research communication intends to evaluate the impact of time‐dependent MHD Darcy–Forchheimer flow of CNTs/Ag nanoparticles on a heated stretchy surface. Water is employed as a base fluid, and two types of CNTs such as single‐ and multiwall carbon nanotubes are considered. The significance of nonlinear radiation and heat sink/source is added to our analysis. To accommodate the suitable variables, the governing nonlinear partial differential models are transformed into a set of ordinary differential models. These resulting models are solved analytically and numerically by utilizing the homotopy analysis technique and the bvp4c procedure in MATLAB. The distinctive behavior of pertinent physical parameters on the dimensionless profiles are displayed and discussed through diagrams, tables, and charts. It is discovered that the velocity profile decrepitude whenever there is a change in the unsteady, porosity, and injection/suction parameters. The space and temperature‐dependent heat sink/source parameter cause to elevate the thermal profile. The Ag nanoparticles have a lesser surface shear stress compared to both CNTs. The heat transfer gradient develops for larger quantities of radiation and temperature ratio parameters. This research has significant applications in many industrial sectors, such as thermal exchangers, chemical reactors, microelectronics, biomedical engineering, aerodynamics, and industrial production processes.

Heat Generation and Thermal Radiation Impacts on Flow of Magnetic Eyring–Powell Hybrid Nanofluid in a Porous Medium

The paper presents the flow of mixed convection boundary layer for Eyring–Powell hybrid nanofluid over a perpendicular plate with changeable temperature and velocity profile. The nondimensional modified controlling equations in non-similar kind are resolved by utilizing hybrid mechanism: local non-similarity procedure in synchronism with RKF45 with the mechanism of shooting. The gained outcomes are offered properly by plots and discussed for different values of governing parameters. It is found that the transport of heat is diminished by increasing the magnetic field and permeability of porous medium. Furthermore, as a thermal radiation and heat generation improved, the heat transfer increased. This study gets enormous applications in industries of glass and polymer, in the field of heat exchangers styling, cooling operations of metallic plates, plastic sheets ejaculation, etc.

Effects of genomic instability in populations of Drosophila melanogaster from regions of Ukraine with different impact of radiation factors

Purpose To investigate differences in the gonadal dysgenesis frequency as one of the indicators of genome instability through natural populations of Drosophіla melanogaster, selected from Ukrainian regions with different radiation impacts. Follow-up study of the dynamics of this indicator under chronic exposure in laboratory conditions for 10 generations. Materials and methods The study was conducted in two stages. The first one included trapping of insects in regions with different radiation loads with subsequent assessment of both the time of maturation and the index of the gonadal dysgenesis through the first (F1) generation, obtained in laboratory conditions. At the second stage, the dynamics of this indicator were investigated for the F1-descendants of each ten consequent generations, which were developed under laboratory conditions both with and without additional gamma-exposure with different characteristics of the dose rate 1.2 × 10−8, 0.3 × 10−8 and 0.12 × 10−8 Gy/sec. Results Differences in the gonadal dysgenesis frequency as one of the indicators of genome instability were revealed in F1-descendants of natural populations of Drosophіla melanogaster, selected from regions of different radiation impact. Under conditions of additional low rate chronic irradiation in laboratory conditions for 10 generations, significant differences in changes in the level and dynamics of this indicator were established depending on the accumulated dose of Drosophila populations from the city of Netishyn (Khmelnytskyi NPP) and Magarach city. There were no signs of adaptation. Conclusions The discrepancy between the real and expected biological effects has reflected the difference in the intensity of the radiation background, which was traditionally determined by the gamma-emitters and did not take into account the wide range of other genotoxic elements from nuclear power emissions. A complex, non-monotonic type of frequency dynamics of gonadal dysgenesis could be determined by the interaction of radiation damage, protection and recovery.

Thermal Radiation and Viscous Dissipation Impacts of Water and Kerosene‐Based Carbon Nanotubes over a Heated Riga Sheet

This research communication explains the flow of water/kerosene‐based CNTs (carbon nanotubes) over a Riga sheet. The energy analysis is debated with the availability of radiation, viscous dissipation, and convective heating conditions. Two divisions of CNTs, like, SWCNTs (single‐wall carbon nanotubes) and MWCNTs (multiwall carbon nanotubes), are considered. The pertinent variables are applied to overhaul the governing mathematical models into ODE expressions. The overhaul expressions are analytically solved by HAM (homotopy analysis method) and numerically solved by MATLAB bvp4c scheme. The repercussions of relevant parameters on nanoliquid velocity, nanoliquid temperature, skin friction coefficient, and local Nusselt number are inspected via graphs, tables, and charts. Our computational results are compared with the previous researcher results and have the most acceptable agreement. Our outcomes are used to understand the flow attributes, behavior, and how to predict it for those working in the design of thermal equipment in thermal industry. It is noticed that the nanoliquid velocity decayed in counter to the unsteady parameter, and it enhances for larger values of Hartmann number. The nanoliquid temperature enriches when raising the Biot number and radiation parameter. The change in unsteady parameter decays the surface shear stress, while reverse results are found in the local Nusselt number.

Magnetic Dipole and Thermal Radiation Impacts on Stagnation Point Flow of Micropolar Based Nanofluids over a Vertically Stretching Sheet: Finite Element Approach

An analysis for magnetic dipole with stagnation point flow of micropolar nanofluids is modeled for numerical computation subject to thermophoresis, multi buoyancy, injection/suction, and thermal radiation. The partial derivative is involved in physical consideration, which is transformed to format of ordinary differential form with the aid of similarity functions. The variational finite element procedure is harnessed and coded in Matlab script to obtain the numerical solution of the coupled non-linear ordinary differential problem. The fluid temperature, velocity, tiny particles concentration, and vector of micromotion are studied for two case of buoyancy (assisting 0<λ, and opposing 0>λ) through finite-element scheme. The velocity shows decline against the rising of ferromagnetic interaction parameter (β) (assisting 0<λ and opposing 0>λ), while the inverse behaviour is noted in micro rotation profile. Growing the thermo-phoresis and microrotation parameters receded the rate of heat transfer remarkable, and micromotion and fluid velocity enhance directly against buoyancy ratio. Additionally, the rate of couple stress increased against rising of thermal buoyancy (λ) and boundary concentration (m) in assisting case, but opposing case shows inverse behavior. The finite element scheme convergency was tested by changing the mesh size, and also test the validity with available literature.

Hybrid Nanofluid Flow over a Permeable Shrinking Sheet Embedded in a Porous Medium with Radiation and Slip Impacts

The study of hybrid nanofluid and its thermophysical properties is emerging since the early of 2000s and the purpose of this paper is to investigate the flow of hybrid nanofluid over a permeable Darcy porous medium with slip, radiation and shrinking sheet. Here, the hybrid nanofluid consists of Cu/water as the base nanofluid and Al2O3–Cu/water works as the two distinct fluids. The governing ordinary differential equations (ODEs) obtained in this study are converted from a series of partial differential equations (PDEs) by the appropriate use of similarity transformation. Two methods of shooting and bvp4c function are applied to solve the involving physical parameters over the hybrid nanofluid flow. From this study, we conclude that the non-uniqueness of solutions exists through a range of the shrinking parameter, which produces the problem of finding a bigger solution than any other between the upper and lower branches. From the analysis, one can observe the increment of heat transfer rate in hybrid nanofluid versus the traditional nanofluid. The results obtained by the stability of solutions prove that the upper solution (first branch) is stable and the lower solution (second branch) is not stable.

Неопределённости в оценке радиационного воздействия на биоту в районах расположения объектов использования атомной энергии

Evaluation of radiation impact on biota inhabiting near nuclear facilities of radioactive release to atmosphere from reactors of different types (WWER-1200, BN-600, BN-800, UVV-2M) is consid-ered in the paper. Radiation dose rates to reference groups of terrestrial biota species (annelids, insects, large and small mammals, grasses and conifers) vary from 0.01 to 0.2 µGy/day. The im-pact of the NPP using up-to-date reactor WWER-1200 is shown to be not exceeding 1% of the to-tal radiation impact. To compare correctly radiation impacts on the biota species from radioactive release and from exposure to established radiation dose rate limits, it is necessary to take into account contribution of all constituents of radiation background. Impacts on biota species from the total exposure to radioactive release or the exposure to established radiation dose rate limits were evaluated. Estimated radiation impact from exposure to the radioactive release did not ex-ceed 0.1; the impact from the established dose rate limits was 0.9. Obtained information allows making the following conclusion: uncertainty of quantitative evaluation of radiation impact on bio-ta in planned radiation situations is mainly caused by uncertainty of established dose rate limits. There is a need to establish dose criteria for emergency, it will allow creating “weighty” radioeco-logic justification of “nuclear power plants with account for potential emergency conditions.

Single Fraction Stereotactic Body Radiation Therapy Induces Dynamic Changes to the Peripheral Blood T Cell Repertoire in Renal Cell Carcinoma Patients

Clinical studies combining radiation and immunotherapy have shown promising response rates, strengthening efforts to sensitize tumors to immune-mediated attack. Thus, there is an ongoing surge in trials using preconditioning regimens with immunotherapy. Yet, due to scarcity of resected tumors treated in situ with radiotherapy, there has been little investigation of radiation’s sole contributions towards local and systemic anti-tumor immunity in patients. Without this access, translational studies have been limited to evaluating circulating immune subsets and systemic remodeling of peripheral T cell receptor repertoires. This constraint has left gaps in how radiation impacts intratumoral responses and whether tumor-resident T cell clones are amplified following treatment. Therefore, to interrogate the immune impact of radiation on the tumor microenvironment and test the hypothesis that radiation initiates local and systemic expansion of tumor-resident clones, we analyzed renal cell carcinoma from patients treated with stereotactic body radiation therapy. Blood and tumor samples were collected from patients prior to nephrectomy for renal cell carcinoma. These samples were compared to samples from patients treated on a 15 patient clinical trial of single fraction stereotactic body radiation therapy delivered 4 weeks prior to nephrectomy. Transcriptomic comparisons were evaluated by bulk RNA sequencing. T cell receptor sequencing monitored repertoires during the 4-week period between SBRT and nephrectomy. Pathway analysis from tumor transcriptomic data showed radiation-specific enrichment of immune-related processes. T cell receptor sequencing revealed increased clonality in radiation-treated tumors. The frequency of identified, tumor-enriched clonotypes was tracked across serial blood samples. Compared to pre-treatment, we observed increased abundance of tumor-enriched clonotypes 2 weeks post-radiation. However, this expansion was not sustained and contracted towards baseline levels 4 weeks after treatment. Altogether, these results indicate robust intratumoral immune remodeling and a window of tumor-resident T cell expansion following radiation that may be leveraged for rational design of combinatorial strategies. Samples from renal cell carcinoma (RCC) patients underwent high-throughput analysis to reveal transcriptional immune activation and increased clonality in irradiated tumors. Analysis across longitudinal blood samples showed tumor-enriched clonotypes undergo phases of peripheral expansion and contraction following radiation. Collectively, these findings demonstrate radiotherapy remodels intratumoral T cell responses and have significant implications for refined sequencing of combination strategies in RCC.

Radiation induces dynamic changes to the T cell repertoire in renal cell carcinoma patients

Clinical studies combining radiation and immunotherapy have shown promising response rates, strengthening efforts to sensitize tumors to immune-mediated attack. Thus, there is an ongoing surge in trials using preconditioning regimens with immunotherapy. Yet, due to the scarcity of resected tumors treated in situ with radiotherapy, there has been little investigation of radiation's sole contributions to local and systemic antitumor immunity in patients. Without this access, translational studies have been limited to evaluating circulating immune subsets and systemic remodeling of peripheral T cell receptor repertoires. This constraint has left gaps in how radiation impacts intratumoral responses and whether tumor-resident T cell clones are amplified following treatment. Therefore, to interrogate the immune impact of radiation on the tumor microenvironment and test the hypothesis that radiation initiates local and systemic expansion of tumor-resident clones, we analyzed renal cell carcinomas from patients treated with stereotactic body radiation therapy. Transcriptomic comparisons were evaluated by bulk RNA sequencing. T cell receptor sequencing monitored repertoires during treatment. Pathway analysis showed radiation-specific enrichment of immune-related processes, and T cell receptor sequencing revealed increased clonality in radiation-treated tumors. The frequency of identified, tumor-enriched clonotypes was tracked across serial blood samples. We observed increased abundance of tumor-enriched clonotypes at 2 wk postradiation compared with pretreatment levels; however, this expansion was not sustained, and levels contracted toward baseline by 4 wk posttreatment. Taken together, these results indicate robust intratumoral immune remodeling and a window of tumor-resident T cell expansion following radiation that may be leveraged for the rational design of combinatorial strategies.

UV-type specific alteration of miRNA expression and its association with tumor progression and metastasis in SCC cell lines.

UV exposure is the main risk factor for development of cutaneous squamous cell carcinoma (cSCC). While early detection greatly improves cSCC prognosis, locally advanced or metastatic cSCC has a severely impaired prognosis. Notably, the mechanisms of progression to metastatic cSCC are not well understood. We hypothesized that UV exposure of already transformed epithelial cSCC cells further induces changes which might be involved in the progression to metastatic cSCCs and that UV-inducible microRNAs (miRNAs) might play an important role. Thus, we analyzed the impact of UV radiation of different quality (UVA, UVB, UVA + UVB) on the miRNA expression pattern in established cell lines generated from primary and metastatic cSCCs (Met-1, Met-4) using the NanoString nCounter platform. This analysis revealed that the expression pattern of miRNAs depends on both the cell line used per se and on the quality of UV radiation. Comparison of UV-induced miRNAs in cSCC cell lines established from a primary tumor (Met-1) and the respective (un-irradiated) metastasis (Met-4) suggest that miR-7-5p, miR-29a-3p and miR-183-5p are involved in a UV-driven pathway of progression to metastasis. This notion is supported by the fact that these three miRNAs build up a network of 81 potential target genes involved e.g. in UVA/UVB-induced MAPK signaling and regulation of the epithelial-mesenchymal transition. As an example, PTEN, a target of UV-upregulated miRNAs (miR-29a-3p, miR-183-5p), could be shown to be down-regulated in response to UV radiation. We further identified CNOT8, the transcription complex subunit 8 of the CCR4-NOT complex, a deadenylase removing the poly(A) tail from miRNA-destabilized mRNAs, in the center of this network, targeted by all three miRNAs. In summary, our results demonstrate that UV radiation induces an miRNA expression pattern in primary SCC cell line partly resembling those of metastatic cell line, thus suggesting that UV radiation impacts SCC progression beyond initiation.

Radiation-Hardened Sensor Interface Circuit for Monitoring Severe Accidents in Nuclear Power Plants

Radiation sensor interface circuits can be mounted on sensor nodes in wireless sensor networks to detect radiation signals. They respond quickly to operators and command centers, allowing appropriate decisions to be made to mitigate nuclear power plant accidents. For instance, high-level radiation leaked from a reactor building during a nuclear plant accident can degrade the performance of the radiation sensor interface implemented by integrated circuits due to threshold voltage shift, leakage current change, and noise increase induced by radiation impact events. To obtain reliable signal measurements in the high radiation environment, radiation-hardening technologies must be applied to radiation sensor interface circuits. The radiation-hardened sensor interface circuit proposed in this article exploits a pair of charge-sensitive amplifiers (CSAs) in dual paths to equivalently cancel out the distorted output signals caused by radiation impacts on the circuits. In addition, a low-power, fully differential successive approximation register (SAR) analog-to-digital converter (ADC) is used to reduce the radiation effects by subtracting the radiation-induced noise of one input from the other. The implemented radiation sensor interface circuit can maintain its performance up to 1.0 mrad (SiO2) of irradiation with only 2.5 mW power consumption, while successfully sensing and transferring the radiation information to the downstream signal-processing network.

Radiation and Magnetic Field Impacts on Time-Dependent Mixed Convection Flow and Heat Transmission of Maxwellian Fluid Past A Stretching Sheet

The current study was devoted to explicating the impacts of heat transmission in an unsteady mixed convection flow of an upper convected Maxwell (UCM) fluid passing over a continuously stretching surface under the influence of radiation and magnetic field. Appurtenant similarity transmutations were adopted in order to express the constitutive boundary layer Equations of flow and heat transmission in non-dimensionalized form. The reduced system of partial differential Equations was solved by implementing the implicit finite difference method (IFDM). Our center of attention was to scrutinize the behavior of influential flow parameters on some significant features of flow and heat transmission, which were briefly examined, discussed, and presented in both graphical and tabular formats. Finally, a comparison was established with existing literature in limiting cases to support the present results, and a good agreement was found, corroborating our work. It was predicted that the thermal diffusion rate could be controlled by varying the Prandtl number. Moreover, a rise in radiation and magnetic field parameters reduced the skin friction coefficient and led to enhance the heat transmission rate at the surface. The outcomes of the study might have viable implementations in order to improve the quality of industrial products.

Structural Changes during Thermal and Radiation Impacts in a Stainless Steel Alloyed with Titanium

Radiation and structural-phase transformations in Fe–16% Cr–15% Ni–3% Mo austenitic steel in the initial and the titanium-alloyed states were studied by measuring the residual electrical resistance after irradiation with 5-MeV electrons and isochronous annealing. Vacancies migrate at temperatures below 320 K and form vacancy clusters upon irradiation. Due to the migration of vacancies during irradiation and upon the dissociation of vacancy clusters during isochronous annealing above 400 K, the separation of the solid solution occurs, which is accompanied by an increase in the electrical resistance. At temperatures above 700 K, the state of the steels, non-irradiated among them, approaches equilibrium due to thermal diffusion. In this case, all the dependences of the electrical resistance on temperature for each alloy irradiated at different temperatures or non-irradiated converge to a common dependence in the region of high temperatures. Doping with titanium inhibits ordering. Intermetallic compounds of Ni3Ti composition were formed thermally upon annealing above 850 K in the alloys doped with titanium, which is accompanied by a decrease in the electrical resistance to below the initial level.

Stimulated Resonance Raman Scattering Considering Radiation Impacts on Energy-Level Populations

A system of equations describing stimulated resonance and spontaneous Raman scattering considering radiation impacts on scattering-center level populations was derived. The contribution of the resonant transition to the Raman gain coefficient was analyzed in the simplest case as a function of the resonance mismatch.

Radiation Impacts on Free Convection Circulation of a Power-Law Fluid past Vertical Plate Filled Along With Darcy Porous Medium

The fluid is actually thought about to be grey, absorbing, and producing yet non-scattering channel. In this study, our team recommend to study the natural convection warmth as well as mass move coming from an upright level embedded in a power-law liquid saturated Darcy permeable resource together with domino effect and radiation effects. The managing partial differential methods are transformed in to ordinary differential formulations using correlation improvements and after that took care of numerically making use of Shooting strategy. It was discovered that speed circulation boosted with improving buoyancy specifications; temp reduced along with enhancing Prandtl amount, and focus minimized along with raising the Schmidt amount.