Thermal slip and variable viscosity analysis on heat rate and magnetic flux through accelerating non-conducting wedge in the presence of induced magnetic field.

The focus of present study is to incorporate the variable viscosity and temperature slip impact on heating rate and induced magnetic gradient along the moving non-conducting wedge under magnetic field. In industrial and engineering procedures, the impact of induced magnetization improves the efficiency of thermal systems to main the heating rates. The similarity transformations and stream functions are applied to reduce the governing equations into ordinary form. During this transformation, the pertinent parameters such as wedge parameter, moving parameter, Prandtl factor, viscosity parameter and temperature-slip parameter is obtained. These parameters play a prominent role on the physical values of fluid velocity, induced magnetic field and temperature distributions. The skin friction, Nusselt coefficient and induced magnetic gradient are incorporated through these parameters. The numerical values are executed by using the Keller box analysis with Newton-Raphson technique. It is depicted that the maximum slip in fluid velocity and temperature distribution is obtained for each values of thermal-slip parameter. It is noticed that maximum magnitude in induced magnetic field is reported for each wedge factor. The maximum velocity slip and temperature slip is observed for each choice of moving parameter. It is reported that the maximum variation in heating rate and induced magnetic gradient is obtained for magnetic force and viscosity parameter. The enhancing behavior of skin friction is observed for maximum values of Prandtl number.

AAPM Task Group Report 325: MRI static magnetic field homogeneity measurement and evaluation procedures - Guidance and resources.

Measurement of static magnetic field (B0) homogeneity is an essential component of routine MRI system evaluation. This report summarizes the work of AAPM Task Group (TG) 325 on vendor-specific methods of B0 homogeneity measurement and evaluation. TG 325 was charged with producing a set of detailed, step-by-step instructions to implement B0 homogeneity measurement methods discussed in the American College of Radiology (ACR) MRI Quality Control Manual using specific makes and models of MRI scanners. The TG produced such instructions for as many approaches as was relevant and practical on six currently available vendor platforms including details of software/tools, settings, phantoms, and other experimental details needed for a reproducible protocol. Because edits to these instructions may need to be made as vendors enter and exit the market and change available tools, interfaces, and access levels over time, the step-by-step instructions are published as a living document on the AAPM website. This summary document provides an introduction to B0 homogeneity testing in MRI and several of the common methods for its measurement and evaluation. A living document on the AAPM website provides vendor-specific step-by-step instructions for performing these tests to facilitate accurate and reproducible B0 homogeneity evaluation on a routine basis.

Magneto-Controlled Tubular Liquid Actuators with Pore Engineering for Liquid Transport and Regulation.

Liquid manipulation using tubular actuators finds diverse applications ranging from microfluidics, printing, liquid transfer to micro-reactors. Achieving flexible and simple regulation of manipulated liquid droplets during transport is crucial for the tubular liquid actuators to perform complex and multiple functions, yet it remains challenging. Here, a facile tubular actuator for directional transport of various liquid droplets under the control of an externally applied magnetic field is presented. The surfaces of the actuator can be engineered with submillimeter-sized through-hole pores, which enables the liquid droplet to be easily modulated in the transport process. Furthermore, the liquid actuator with featured through-hole pores is expanded to function as a switch in an integrated external electric circuit by magnetically controlling the motion of a conductive liquid droplet. This work develops a strategy for regulating liquid droplets in the tubular actuation systems, which may inspire ideas for designing functional liquid actuators with potential applications in microfluidics, microchemical reaction, liquid switch, and liquid robotics.

Optimization of polymer coating thickness and strut width in drug Eluting stents using Magnetic field.

The transport of drug/magnetic particle (MP) conjugates in the presence of a Magnetic Field (MF) in Drug Eluting Stents (DESs) is modeled numerically using the Finite Volume Method (FVM). The effects of physiological conditions corresponding to different degrees of calcification, drug particles sizes and hematocrit level, were analyzed by investigating the roles of the tissue permeability, its anisotropy and the plasma viscosity. It was found that both in the absence and presence of the MF, as the tissue permeability decreases or the plasma viscosity increases, the free-phase drug and Extracellular Matrix (ECM)-bound phase contents increase. Stronger tissue anisotropy leads to a decrease of the free-phase drug content and an increase of the ECM-bound phase content. Within the explored ranges, the Specific Receptor (SR)-bound phase of the drug was found to be insensitive to the tissue permeability and plasma viscosity, and to be larger in anisotropic tissues. The activation of the MF leads systematically to larger free-phase drug contents, with the increases most prominent at smaller tissue permeability, anisotropy and plasma viscosity. On the other hand, the effects on the ECM-bound phase content are found to be stronger at larger permeability, smaller plasma viscosity and lower tissue anisotropy. For an isotropic tissue, the MF induces a decrease of the ECM-bound phase content at early times, followed by an increase at later times. For the considered ranges of permeability and viscosity, the MF does not seem to have any noticeable effects on the SR-bound phase. However, this phase of the drug tends to increase with the activation of the MF in isotropic tissues and is unchanged in anisotropic ones. These reported effects of the MF hold promise for alleviating two factors contributing to In-Stent Restenosis, namely the polymer coating width and thickness. The study reveals that a narrower or thinner polymer layer, in combination with the MF, can mimic the drug release dynamics of a wider or thicker polymer layer in the absence of the MF. The corresponding width and thickness of the magnetized stents, that we referred to as the equivalent polymer width (EPW) and equivalent polymer thickness (EPT) were determined and their dependence on the tissue permeability, isotropy and the plasma viscosity, was investigated. The study shows that it is possible to achieve the same drug delivery with polymer coating of half the width or half the thickness of the non-magnetized stent when an electric intensity of 3A is used.

Scalable, Flexible, Magnetic-Field-Guided rULGO Sponge-BN-Cobalt Oxide-Based Supercapacitors: Mechanistic Insights into Multiple Charge Transfer Pathways by the Distribution of Relaxation Times.

Scalable and flexible supercapacitors are in high demand from an application point of view. Through our exploration, we have attained promising performance of electrochemical energy storage under the influence of an external magnetic field for future energy-based applications. In this work, a commercial sponge is used as a template for ultra-large graphene oxide (rULGO) functionalization, followed by the incorporation of Co3O4:BN without the inclusion of binders or conductive additives. The fabricated electrodes, namely, SPG-rULGO and SPG-rULGO-Co3O4:BN, demonstrate superior performance with a potential window of 2.2 V at a magnetic field strength of 13.5 and 28 mT, respectively. A specific capacitance of 218 ± 5% F·g-1 and 312 ± 5% F·g-1, respectively, with retention rates of 80 and 88% over 5000 charge-discharge cycles are achieved. In contrast to the conventional fabrication of the asymmetric device, both electrodes are made using flexible substrates with SPG-rULGO-Co3O4:BN as the positive electrode and SPG-rULGO as the negative electrode eliminating the need to use activated carbon. This configuration yields a specific capacitance of 153 ± 5% F·g-1 at 1 Ag-1, leading to a high energy density of 103 ± 5% W·h·kg-1 at a power density of 1.10 ± 5% kW kg-1 with an 85% retention rate. The charge-discharge mechanism of bare and modified electrodes is probed by the distribution of relaxation time analysis of the coupled electrochemical impedance spectra. The integration of magnetic field with advanced electrode materials opens up other possibilities for optimizing energy storage systems and advancing the field of flexible and mechanically robust supercapacitors.

Reconstruction of Ferromagnetic/non-magnetic Cobalt-based Electrocatalysts under Gradient Magnetic Fields for Enhanced Oxygen Evolution.

The rational manipulation of the surface reconstruction of catalysts is a key factor in achieving highly efficient water oxidation, but it is a challenge due to the complex reaction conditions. Herein, we introduce a novel in situ reconstruction strategy under a gradient magnetic field to form highly catalytically active species on the surface of ferromagnetic/non-magnetic CoFe2O4@CoBDC core-shell structure for electrochemical oxygen evolution reaction (OER). We demonstrate that the Kelvin force from the cores' local gradient magnetic field modulates the shells' surface reconstruction, leading to a higher proportion of Co2+ as active sites. These Co sites with optimized electronic configuration exhibit more favorable adsorption energy for oxygen-containing intermediates and lower the activation energy of the overall catalytic reaction. As a result, a significant enhancement in OER performance is achieved with a large current density increment about 128% at 1.63 V and an overpotential reduction by 28 mV at 10 mA cm-2 after reconstruction. Interestingly, after removing the external magnetic field, the activity could persist for over 100 h. This work showcases the directional surface reconstruction of catalysts under a gradient magnetic field for enhanced water oxidation.

Different duration of exposure to a pulsed magnetic field can cause changes in mRNA expression of apoptotic genes in oleic acid-treated neuroblastoma cells.

PURPOSE: Neuroblastoma, a prevalent childhood tumor, poses significant challenges in therapeutic interventions, especially for high-risk cases. This study aims to fill a crucial gap in our understanding of neuroblastoma treatment by investigating the potential molecular impacts of short- and long-term pulsed magnetic field exposure on the neuronal apoptosis mechanism in an in vitro model of neuroblastoma treated with oleic acid (OA). MATERIALS AND METHODS: Cells were cultured and divided into six following experimental groups: (I) Nontreated group (NT); (II) OA-treated group (OA); (III) Group treated with OA after being exposed to the pulsed magnetic field for 15-min (15 min PEMF + OA); (IV) Group treated with OA after being exposed to the pulsed magnetic field for 12 h (12 h PEMF + OA); (V) Group exposed to the pulsed magnetic field for 15 min (15 min PEMF); and (VI) Group exposed to the pulsed magnetic field for 12 h (12 h PEMF). Cell viability, rates of apoptosis, and mRNA levels of key apoptotic genes (TP53, Bcl2, Bax, and Caspase-3) were assessed. RESULTS: Significant reductions in cell viability were observed, particularly in the group treated with OA following long-term pulsed magnetic field exposure. Flow cytometry revealed elevated apoptosis rates, notably in the early stages of apoptosis. qRT-PCR analysis demonstrated increased expression of cleaved Caspase-3, Bax/Bcl2 ratio, and TP53 in cells treated with OA following long-term pulsed magnetic field exposure, signifying enhanced apoptotic pathways. CONCLUSIONS: The findings indicate that long-term pulsed magnetic field exposure and OA treatment exhibit potential synergistic effects leading to the induction of apoptosis in SH-SY5Y cells. We have concluded that stimulations of pulsed magnetic field have the potential to serve as an adjuvant therapy for oleic acid-based treatment of neuroblastoma.

Dynamically Reconfigurable Micro-Patterned Hydrogels Based on Magnetic Pickering Emulsion Droplets.

Reconfigurability within hydrogels has emerged as an attractive functionality that can be used in information encryption, cargo/delivery, environmental remediation, soft robotics, and medicine. Here micro-patterned polymer hydrogels capable of temperature-dependent reconfigurability are fabricated. For this, the hydrogels are provided with micron-sized Pickering emulsion droplets stabilized by magnetic particles, which are capable of harnessing energy from external force fields. The droplets can both migrate under magnetic field gradients and heat the environment when laser irradiated. These functions not only affect a single compartment but have higher-order effects on the mesoscale, thanks to the temperature-responsiveness of the polymeric network. This double responsiveness is exploited to control the spatial organization of hundreds of droplets within the hydrogel matrix and form predesigned and sophisticated patterns. Furthermore, pattern self-reconfiguration driven by the droplets themselves upon laser irradiation is induced. Finally, we show that due to their internal liquid phase, the droplets can be used as reservoirs of hydrophobic nutrients for living cells (i.e., Yarrowia lipolytica yeast) in the solid-like environment of the polymeric network, and demonstrate communication between the droplets and the cells to facilitate nutrient uptake. Altogether, the results provide opportunities for the development of stimuli-sensitive polymer hydrogels with post-synthesis reprogrammable response using micro-compartments as building blocks.

Microstructure induction of quaternary ammonium chitosan microcapsules based on magnetic field and study of their aroma release.

Traditional pressure-sensitive microcapsules used in textiles face challenges of insufficient environmental friendliness in the production process and uncontrollable fragrance release. To address this issue, this study utilized quaternary ammonium chitosan and silica as wall materials to develop a magnetic aromatic microcapsule. The microstructure of the microcapsules was controlled by magnetic field induction, and its evolution pattern was investigated. After magnetic field induction, the microcapsules exhibited a trend of evolving from spherical to asymmetrical shapes, accompanied by significant changes in mechanical properties. Asymmetrical microcapsules showed higher adhesion and lower stiffness. When applied to cotton textiles, the cotton textiles treated with asymmetrical microcapsules released 63.40 % of lavender essential oil after 200 friction cycles, representing an 11.3 % improvement in release efficiency compared to regular microcapsules, indicating better mechanical stimulus responsiveness. Additionally, in antibacterial tests, aromatic cotton exhibited a 96.52 % inhibition ratio against Escherichia coli. In summary, this study explores methods to adjust the mechanical properties of microcapsules and the relationship between mechanical properties and microstructure, providing a new approach for functional textiles.

Effect of hot isostatic pressing on microstructure and properties of cooled hot dip aluminum coating in magnetic field.

The effect of hot isostatic pressing (HIP) on the microstructure and properties of hot dip aluminum coating cooled in a magnetic field was investigated in this study. In order to improve the microstructure and properties of magnetic dip aluminum coating, hot isostatic pressing technology was used for post-treatment. Initially, a traditional aluminum-impregnated coating was prepared on the surface of titanium alloy TA15, an alternating electromagnetic field was applied during the forming and solidification process of the coating. Finally, the coating was treated with hot isostatic pressing technology. Analyzed three different coatings of the microstructure and element distribution, and tested the microhardness of the coatings at various positions. The test results revealed that the TA15 titanium alloy hot-dip aluminum coatings obtained through the three different processes exhibited a gradient structure. Compared with the traditional hot-dipped aluminum air-cooled coating, when an appropriate intensity of alternating electromagnetic field was applied during the coating solidification process, the outer coating structure was enhanced, the number of holes was reduced, the microstructure density increased, and the number of cracks significantly decreased. The defects of the 800 °C hot isostatic magnetic cold and hot dip aluminum coating were repaired under high temperature and pressure, resulting in a uniform and fine microstructure. The comprehensive properties of the magnetic cold and hot dip aluminum coating on the surface of the titanium alloy were effectively enhanced through hot isostatic pressing.

[Possibilities for increasing the effectiveness of treatment of respiratory infections of the upper respiratory tract in children of various age groups]. / Vozmozhnosti povysheniya effektivnosti terapii respiratornykh infektsii verkhnikh dykhatel'nykh putei u detei razlichnykh vozrastnykh grupp.

The article discusses the experience of complex therapy of rhinitis and sinusitis in children of various age groups, confirming the effectiveness of the combined effects of local thermotherapy, pulsed red light and low-frequency magnetic field. This combination of physical factors has an anti-inflammatory, decongestant, stimulating local cellular activity effect and helps to increase the effectiveness and reduce the overall treatment time for these diseases. The purpose of the study is to evaluate the effectiveness of the combined use of heat, red spectrum phototherapy and magnetic field in the treatment of children with rhinitis and sinusitis. Materials and methods. The observation included 30 children with rhinitis and 40 children with sinusitis aged 2-18 years, receiving combined physiotherapy procedures as part of the main treatment. Results and its discussion. The positive effect of the combined effects of thermotherapy, pulsed light radiation in the red range and low-frequency magnetic field on clinical symptoms and functional indicators of nasal breathing in children with rhinitis and sinusitis has been confirmed. Conclusions. The use of a course of procedures combined with the effects of local thermotherapy, pulsed red light and low-frequency magnetic field against the background of the main treatment helps to increase the effectiveness of the treatment of respiratory infections of the upper respiratory tract in children of various age groups.

[The effect of electromagnetic fields on tendinopathies : Study on the effect analysis of a singular application of high-energy pulsed electromagnetic fields]. / Die Wirkung von elektromagnetischen Feldern auf Tendinopathien : Studie zur Effektanalyse einer singulären Anwendung von hochenergetischen gepulsten elektromagnetischen Feldern.

OBJECTIVE: Tendinopathies are diseases that often entail long-term treatment consisting of analgesics, physiotherapy, orthotics, and sparing. The aim of this study was to investigate the effect of a single application of a high-energy PEMF (pulsed electromagnetic field) on pain perception and blood born inflammation parameters. METHODS: 34 patients were randomly assigned to a verum group (10 min PEMF, 0,78 T) or a placebo group (10 min sham condition). Prior to and up to one week after the patient blinded treatment (t1-t5), local pain state was assessed by means of algometry as pain pressure threshold (PPT). Accordingly, heat-shock protein 70 (HSP70) levels were analysed. Statistical analyses included 2­way ANOVA (2â€¯× 5). The clinical trial was registered (DRKS00031321). RESULTS: After randomization and drop-out (verum n = 17, placebo n = 13) baseline-analyses did not reveal significant between-group differences for PPT (p = 0,096), for HSP70 (p = 0,524), or any other sample characteristics (p > 0,05). Pain reduction during one week of observation showed to be significantly higher (p = 0,045, η2 = 0,013) for the PEMF group (PPT: +83 bis +139%) compared to the placebo group (PPT: +10 bis +36%). There were no HSP70 associated effects. CONCLUSIONS: A single bout of high energy PEMF led to an immediate pain relief in tendinopathy patients lasting at least for one week, but the hypothesized underlying HSP70 associated inflammatory pathway could not be confirmed.

Effect of applying a magnetic field on the biofiltration of hexane over long-term operation period.

The present study reports on the effect of magnetic field (MF) intensity on the biofiltration of hexane vapors. MF ranging from 0 to 30 mT (millitesla) was used to evaluate the biofiltration of hexane for 191 days under a fixed inlet load of 40 g m-3 h-1. A homogeneous MF generated by Helmholtz coils was used. The performance of the reactors was evaluated in terms of removal efficiency (RE), elimination capacity (EC), biomass content, and exopolysaccharide (EPS) production. Maximal removal efficiencies of 25%, 36%, and 40% were found for the control (H0), 10 mT (H10), and 30 mT (H30) reactors, corresponding to ECs of 14.2, 15, and 18 g m-3 h-1, respectively. In the last period (days 94 to 162), H10 and H30 showed 40% of RE improvement compared with Ho. Also, the removal occurred all along the bioreactor height for biofilters exposed to MF. Reactors achieved a total biomass content of 152, 180, and 147 mg VS (volatile solids) g-1 dry perlite for H0, H10, and H30, correspondingly, associated with EPS production of 30, 30, and 40 mg EPS g-1 VS. The main components of EPS affected by the MF were carbohydrates and glucuronic acid; proteins were slightly affected. Experiments with MF pulses of 4 and 2 h confirmed that MF exposure improved the removal efficiency of hexane, and after the pulse, removal enhancement was maintained for 5 days. Thus, the MF application by pulses could be an economically and friendly technology to improve the RE of volatile organic compounds (VOCs).

Comparative sensitivity of A-type and B-type starch crystals to ultrahigh magnetic fields.

In this study, maize starch (A-type) and potato starch (B-type) were treated with ultrahigh magnetic fields (UMF) of different intensities (5 T and 15 T) to investigate their sensitivity to UMF by measuring changes in their structure and rheological properties. The results indicate that the crystallinity of A-type starch significantly decreases, reaching a minimum of 20.01 % at 5 T. In contrast, the crystallinity of B-type starch significantly increases, peaking at 21.17 % at 15 T, accompanied by a brighter polarized cross and a more perfect crystal structure. Additionally, B-type starch exhibited a significant increase in double helix content (from 32.67 % to 42.07 %), branching degree (from 1.96 % to 3.84 %), and R1022/995 (from 0.803 to 0.519), compared to A-type starch. B-type starch also showed a greater propensity for cross-linking reactions forming OCOR groups (from 0 % to 6.81 %), and its enthalpy change (∆H) increased substantially (from 19.28 J/g to 31.70 J/g), indicating a marked enhancement in thermal stability. Furthermore, the average hydrodynamic radius (Rh) decreased more for B-type starch, reflecting an increase in gel strength. These findings demonstrate that B-type starch is more sensitive to UMF than A-type starch. This study provides foundational data on the effects of UMF treatment on different crystalline starches, aiming to explore its potential applications in food and industrial fields.

Impact of 1.5†T Magnetic Field on Treatment Plan Quality in MR-Guided Radiotherapy: Typical Phantom Test Cases.

PURPOSE: This study aims to investigate the influence of the magnetic field on treatment plan quality using typical phantom test cases, which encompass a circle target test case, AAPM TG119 test cases (prostate, head-and-neck, C-shape, multi-target test cases), and a lung test case. MATERIALS AND METHODS: For the typical phantom test cases, two plans were formulated. The first plan underwent optimization in the presence of a 1.5 Tesla magnetic field (1.5 T plan). The second plan was re-optimized without a magnetic field (0 T plan), utilizing the same optimization conditions as the first plan. The two plans were compared based on various parameters, including con-formity index (CI), homogeneity index (HI), fit index (FI) and dose coverage of the planning target volume (PTV), dose delivered to organs at risk (OARs) and normal tissue (NT), monitor unit (MU). A plan-quality metric (PQM) scoring procedure was employed. For the 1.5 T plans, dose verifications were performed using an MR-compatible ArcCHECK phantom. RESULTS: A smaller dose influence of the magnetic field was found for the circle target, prostate, head-and-neck, and C-shape test cases, compared with the multi-target and lung test cases. In the multi-target test case, the significant dose influence was on the inferior PTV, followed by the superior PTV. There was a relatively large dose influence on the PTV and OARs for lung test case. No statistically significant differences in PQM and MUs were observed. For the 1.5 T plans, gamma passing rates were all higher than 95% with criteria of 2 mm/3% and 2 mm/2%. CONCLUSION: The presence of a 1.5 T magnetic field had a relatively large impact on dose parameters in the multi-target and lung test cases compared with other test cases. However, there were no significant influences on the plan-quality metric, MU and dose accuracy for all test cases.

Enhanced bioleaching of spent Li-ion batteries using A. ferrooxidans by application of external magnetic field.

Recycling spent batteries is increasingly important for the sustainable use of Li-ion batteries (LIBs) and for countering the supply uncertainty of critical raw minerals (Li, Co, and Ni). Bioleaching, which uses microorganisms to extract valuable metals, is both economical and environmentally safe compared to other recycling methods, but its practical application is impaired by slow kinetics. Accelerating the process is a key for bioleaching spent LIBs on an industrial scale. Acidithiobacillus ferrooxidans (A. ferrooxidans), which thrives in extremely low pH conditions, has long been explored for bioleaching of spent LIBs. Metabolism of A. ferrooxidans involves the oxidation of magnetic Fe2+ and produces intracellular magnetic nanoparticles. The possibility of accelerating the leaching kinetics of A. ferrooxidans by the application of an external magnetic field is explored in this work. A weak static magnetic field is applied during the bioleaching of spent LIBs to recover Li, Ni, and Co using A. ferrooxidans. It is determined that 3 mT is the optimal field strength which allows the leaching efficiency of Li to reach 100% after only 2 days of leaching at a pulp density of 3 w/v % while without the external magnetic field, the leaching efficiency is limited to 57% even after 4 days. The leaching efficiency of Ni and Co also increases by nearly three-fold to >80% after 4 days of leaching. The proposed magnetic field-assisted bioleaching of spent LIBs using A. ferrooxidans substantially improves the leaching kinetics and thus the cost-effectiveness of the bioleaching process with minimal environmental impact, hence enabling environment-friendly recycling of raw materials that are increasingly becoming scarce. The positive effect of an external magnetic field on the metabolism of A. ferrooxidans demonstrated in this work provide a new set of tools to engineer the bioleaching process and the possibility for genetic modification of acidophile bacteria, especially targeted for magnetic enhancement.

Magnetic manipulation of the reactivity of singlet oxygen: from test tubes to living cells.

Although magnetism undoubtedly influences life on Earth, the science behind biological magnetic sensing is largely a mystery, and it has proved challenging, especially in the life sciences, to harness the interactions of magnetic fields (MFs) with matter to achieve specific ends. Using the well-established radical pair (RP) mechanism, we here demonstrate a bottom-up strategy for the exploitation of MF effects in living cells by translating knowledge from studies of RP reactions performed in vitro. We found an unprecedented MF dependence of the reactivity of singlet oxygen (1O2) towards electron-rich substrates (S) such as anthracene, lipids and iodide, in which [S ˙+ O2 ˙-] RPs are formed as a basis for MFs influencing molecular redox events in biological systems. The close similarity of the observed MF effects on the biologically relevant process of lipid peroxidation in solution, in membrane mimics and in living cells, shows that MFs can reliably be used to manipulate 1O2-induced cytotoxicity and cell-apoptosis-related protein expression. These findings led to a 'proof-of-concept' study on MF-assisted photodynamic therapy in vivo, highlighting the potential of MFs as a non-invasive tool for controlling cellular events.

Global preventive feedback of powerful radio jets on galaxy formation.

Firmly anchored on observational data, giant radio lobes from massive galaxies hosting supermassive black holes can exert a major negative feedback effect, by endowing the intergalactic gas with significant magnetic pressure hence retarding or preventing gas accretion onto less massive halos in the vicinity. Since massive galaxies that are largely responsible for producing the giant radio lobes, this effect is expected to be stronger in more overdense large-scale environments, such as protoclusters, than in underdense regions, such as voids. We show that by redshift [Formula: see text] halos with masses up to [Formula: see text] are significantly hindered from accreting gas due to this effect for radio bubble volume filling fraction of [Formula: see text], respectively. Since the vast majority of the stars in the universe at [Formula: see text][Formula: see text] 2 to 3 form precisely in those halos, this negative feedback process is likely one major culprit for causing the global downturn in star formation in the universe. It also provides a natural explanation for the rather sudden flattening of the slope of the galaxy rest-frame UV luminosity function around [Formula: see text]. A cross-correlation between protoclusters and Faraday rotation measures may test the predicted magnetic field. Inclusion of this external feedback process in the next generation of cosmological simulations may be imperative.

Data analysis of thermal performance and irreversibility of convective flow in porous-wavy channel having triangular obstacle under magnetic field effect.

Mixed convective nanofluid flow has substantial importance in improvement of thermal performance, and thermal engineering to meet the global energy crisis. In this study, mixed convective nanofluid flow in a porous-wavy channel with an inner heated triangular obstacle under magnetic field effect is numerically examined. Nanofluid within the channel is heated and cooled from its bottom and top wavy-surfaces. A heated triangular cylinder is located at the centerline of the wavy-channel. Finite element method is utilized to solve the non-dimensional governing equations. The code is validated comparing present results with published numerical and experimental results. The response surface method is also implemented to analyze the obtained results and its sensitivity. The numerical results indicate that strength of flow velocity is accelerated with rising Reynolds number, Darcy numbers and inlet-outlet ports length but declined for Hartmann number and volume fraction. Heat transferring rate and heat transfer irreversibility are substantially increased for higher values of Reynolds number, inlet-outlet ports length, Darcy number and nanoparticle volume fraction but a reverse trend is occurred for magnetic field effect. The thermal performance is found significantly improved with simultaneous increment in Re, ϕ, Da and decrement in Ha. Positive sensitivity is achieved for input factors Re, ϕ, Da in computing N u a v while negative sensitivity to Ha. Heat transfer rate is found more sensitive to the impact of Re and ϕ compared to Da and Ha. 45.59 % more heat transmission potentiality is developed for using Al2O3-H2O nanofluid (vol.5 %) instead of using base fluid water. Heat transfer enhancement rate is decreased by 36.22 % due to impact of magnetic field strength. In addition, 84.12 % more heat transferring rate is recorded in presence of triangular obstacle. Moreover, irreversibility components are influenced significantly for the presence of heated triangular obstacle. Bejan number is also found declined for increasing physical parameters. The findings of this investigation may offer a guideline for finding experimental results to design high-performance convective heat exchangers.

ESR Essentials: basic physics of MR safety-practice recommendations by the European Society for Magnetic Resonance in Medicine and Biology.

OBJECTIVES: The use of magnetic resonance imaging (MRI) is safe from a long-term perspective since there are no known cumulative risks for patients or personnel. However, the technique comes with several acute risks associated with the powerful electromagnetic fields that are necessary to produce medical images. These risks include, among other things, a projectile hazard, loud noise, and the risk of heating. Safe use of MRI requires knowledge about the different hazards related to MRI and organizational structured work including the implementation of routines describing a safe workflow from the referral of a patient to the signed report. In this article, the risks associated with MRI are described along with suggestions for how each risk can be minimized or eliminated. CONCLUSION: The aim of this article is to provide support for the development of, and compliance with, MRI safety routines, and to work with the technique in a safe way. The scope of this treatise does not cover specific details of implant safety, however, the physical principles described can be applied to the risk assessment of implants. KEY POINTS: Establish whether any MR contraindications apply to the patient. Evaluate means to deal with identified risks for both patients and personnel. It is imperative to always perform and document a risk-benefit assessment.