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Computational astrophysics routinely combines grid-adaptive capabilities with modern shock-capturing, high resolution spatio-temporal schemes on multi-dimensional hydro- and magnetohydrodynamics. We provide an update on developments within the open-source MPI-AMRVAC code. With online documentation, the MPI-AMRVAC 3.0 release includes several added equation sets, and many options to explore and quantify the influence of implementation details. Showcasing this on a variety of hydro and MHD tests, we document new modules of interest for state-of-the-art solar applications. Test cases address how higher order reconstructions impact long term simulations of shear layers, with and without gas-dust coupling, how runaway radiative losses transit to intricate multi-temperature, multi-phase dynamics, and how different flavors of spatio-temporal schemes and magnetic monopole control produce consistent MHD results in combination with adaptive meshes. We demonstrate Super-Time-Stepping strategies for specific parabolic terms and give details on all implemented Implicit-Explicit integrators. A new magnetofrictional module can be used for computing force-free magnetic fields or for data-driven time-dependent evolutions, while the Regularized-Biot-Savart-Law approach can insert fluxropes in 3D domains. Synthetic observations of 3D MHD simulations can be rendered on-the-fly, or in post-processing, in many spectral wavebands. A particle module and a generic fieldline tracing, compatible with the hierarchical meshes, can be used to sample information at prescribed locations, to follow dynamics of charged particles, or realize two-way coupled simulations between MHD setups and field-aligned non-thermal processes. Highlighting the latest additions and various technical aspects, our open-source strategy welcomes any further code usage, contribution, or spin-off development., Accepted for A&A

We report on results of high resolution two fluid non-linear simulations of the Rayleigh Taylor Instability (RTI) at the interface between a solar prominence and the corona. These follow results reported earlier by Popescu Braileanu et al. (2021a,b) on linear and early non-linear RTI dynamics in this environment. The simulations use a two fluid model that includes collisions between neutrals and charges, including ionization/recombination, energy and momentum transfer, and frictional heating. High resolution 2.5D magnetized RTI simulations with the magnetic field dominantly normal to and slightly sheared with respect to the prominence plane demonstrate that in a fully developed state of RTI a large fraction of the gravitational energy of a prominence thread can be converted into quasi-turbulent energy of the magnetic field. RTI magnetic energy generation is further accompanied by magnetic and plasma density structure formation, including dynamic formation, break-up, and merging of current sheets and plasmoid sub-structures. The simulations show the role of flow decoupling and ionization/recombination reactions between the neutrals and charges on the structure formation in magnetized RTI. We provide a careful examination of sources and form of numerical dissipation of the evolving magnetic field structures.

The influence of the severe plastic deformation via high-speed high-pressure torsion (HSHPT) on the structural and magnetic properties of the Zr13Co87 alloys is investigated. Moderate applied deformation promotes the growth of the rhombohedral hard magnetic phase leading to the increase of the sample’s hardness and magnetic coercivity. A higher degree of deformation affects the samples morphology leading to a critical value of the grain size under which the exchange coupling of the soft phase is less effective. Additionally, it produces a random alignment of the anisotropy axes, which are both detrimental to the hard magnetic properties.

Background Radiotherapy (RT) may be used as a complementary or palliative treatment for selected cases of malignant cardiac tumors, and improves the overall and relapse-free survival in cardiac sarcomas (1–3). Its use is limited by the risk of radiation injury on the cardiac structures (4). Only few data about the safety of cardiac RT are available. Purpose This study aimed to assess the short and long term adverse cardiac effects in a cohort of patients with cardiac malignancies treated with RT directly on the heart. Methods We reviewed the clinical and echocardiographic data of 25 patients (pts) treated with cardiac RT from 2002 to 2021, using Intensity Modulated RT or Tomotherapy at doses of 25–59 Gy over 5–25 fractions for primary or metastatic tumors (21 sarcomas). The patients had ECG and echocardiogram (ECHO) before RT and weekly during the treatment. After RT, the cardiac surveillance included a visit with ECG and ECHO every 3 months for the first 2 years, every 6 months for 3 years, and yearly thereafter. We compared the left ventricular ejection fraction (LVEF) before RT and at the last available follow-up for all patients; for 12 pts whose radiation field included the right chambers, we analyzed also the right ventricular shortening fraction (RVSF) at the last available follow-up. Results The pts were 14 males, 11 females, aged 22 to 75 (median 54) when treated. The intent was adiuvant after R1 surgery in 12 pts, preoperative in 3, palliative or curative for metastatic or unresectable tumors or in patients refusing redo surgery or chemotherapy (10 pts). Anthracyclines chemotherapy was used in 19 pts. The radiation field included the left atrium and/or ventricle in 11 pts, the right heart in 9, both left and right structures in 3. Two pts were lost to follow-up after 36 and 50 months; 17 died, 3 to 175 months after RT (median 12), all for non-cardiac causes; 6 are alive (with complete local remission) 15 to 126 months (median 79) after completing RT. Acute toxicities were: atrial fibrillation in 2 pts, pericarditis in 2 (both reverted in one week with medical therapy) and temporary worsening of ventricular arrhythmias in one pt with myocardial metastases. At last follow-up no significant valvular or pericardial disease was evident; the LVEF was >50% in all pts (5–10% decreased -compared to baseline- in 2 pts, improved in 3, stable in the others) and the RVSF was >35%. Conclusions In our experience, RT may be used in the treatment of cardiac malignancies with little adverse effects both on short term and at a median follow-up of 13 months (and lasting up to >10 years). Funding Acknowledgement Type of funding sources: None.

The effects of severe plastic deformation (SPD) process via high-speed high-pressure torsion technique on martensitic transformation of Ni–Fe–Ga Heusler shape memory alloy are the subject of this work. The results show that moderate degrees of deformation lead to a decrease in the martensitic transformation temperatures, while the heat of reaction is enhanced only for the sample processed with the lowest degree of deformation. The results are explained by the interplay between the constituent tetragonal L10 and the cubic gamma crystal structures and the evolution of the samples morphology with the severity of deformation. The reduction in the samples granulation due to the progressive increase in the SPD is reflected by the magnetic properties of the samples with decreasing coercivity and Curie temperatures. At the highest applied degree of deformation, sample nanostructuring and a possible amorphization might explain the vanishing of MT.

Funding Acknowledgements Type of funding sources: None. OnBehalf MASCOT investigators Background Few studies analyzed left atrial (LA) peak atrial longitudinal strain (PALS) determinants, particularly across heart failure (HF) stages. We aimed to analyze the pathophysiological and clinical PALS correlates in a large international prospective registry. Methods This is a multicenter prospective observational study enrolling 745 patients with HF stages 0-C from July to October 2018. Data included PALS and left ventricular global longitudinal strain (LV-GLS). Exclusion criteria were: valvular prosthesis; atrial fibrillation; cardiac transplantation; poor acoustic window. Results Median global PALS was 17% [24-32]. 29% of patients were in HF-stage 0/A, 35% in stage-B, and 36% in stage-C. Together with age, the echocardiographic determinants of PALS were LA volume and LV-GLS (overall model R²=0.50, p Conclusion Although influenced by LV-GLS and LA size across HF-stages, PALS is incrementally and independently associated with clinical status. LA function may reflect a substantial part of the hemodynamic consequences of ventricular dysfunction. Abstract Figure 1

Scoliosis is one of the most frequent spine deformities encountered in children and is regularly discovered after 15 years of age with a girls to boys ratio of 2:1. Vertebral arthrodesis involves both short and long term complications. Neurological complications consist of nerve root injuries, cauda equina or spinal cord deficit. Traction is a good orthopaedic technique of progressive deformity correction which attempts to minimize complications. The purpose of this study is to assess the complications that arise during halo gravity traction and to evaluate the correction of the scoliotic curves under traction. A single centre prospective study was conducted on 19 paediatric patients suffering from scoliosis that were admitted between 2019–2022. Traction-related complications were encountered in 94.7% of patients, with the most frequent being cervical pain (89.5%). It was followed by back pain, in 36.8% of the cases, with just 5.3% of the cases having experienced vertigo or pin displacement. Neurological symptoms were present in 26.3% of the patients and pin pain and pin infection equally affected 26.3% of patients. Even though minor halo related complications are frequent, with proper patient monitoring they can be addressed, thus making traction a safe method for progressive curve correction.

Dysplasia epiphysealis hemimelica (DEH), also known as Trevor’s disease, is a rare nonhereditary skeletal disorder affecting one side of the epiphyses or the epiphyses-equivalents. It is often misdiagnosed for traumatic injuries, infections, or other tumors because of the nonspecific clinical features. The diagnosis is mostly based on radiographic involvement of one half of the epiphysis displaying an overgrowth; it is hard to distinguish between DEH and osteochondroma on the gross hystopathological exam. There are few immunohistochemical markers, as well as genetic tests, for EXT1 and EXT2 gene expression that can reveal a more accurate diagnosis. No evidence of malignant changes has been reported and no hereditary transmission or environmental factor has been incriminated as an etiological factor. The natural history of the disease is continuous growth of the lesions until skeletal maturity. Without treatment, the joint might suffer degenerative modification, and the patient can develop early onset osteoarthritis. In the present paper, we report two new cases of DEH of the ankle. The aim of this paper is to consider Trevor’s disease when encountering tumoral masses in the epiphyses of pediatric patients and to present our treatment approach and results.

The influence of the rapid solidification technique and heat treatment on the martensitic transformation, magnetic properties, thermo- and magnetic induced strain and electrical resistivity is investigated for the Cu doped NiMnGa Heusler-based ferromagnetic shape memory ribbons. The martensitic transformation temperatures are unexpectedly low (below 90 K—which can be attributed to the disordered texture as well as to the uncertainty in the elements substituted by the Cu), preceded by a premartensitic transformation (starting at around 190 K). A thermal treatment slightly increases the transformation as well as the Curie temperatures. Additionally, the thermal treatment promotes a higher magnetization value of the austenite phase and a lower one in the martensite. The shift of the martensitic transformation temperatures induced by the applied magnetic field, quantified from thermo-magnetic and thermo-magnetic induced strain measurements, is measured to have a positive value of about 1 K/T, and is then used to calculate the transformation entropy of the ribbons. The magnetostriction measurements suggest a rotational mechanism in low fields for the thermal treated samples and a saturation tendency at higher magnetic fields, except for the temperatures close to the phase transition temperatures (saturation is not reached at 5 T), where a linear volume magnetostriction cannot be ruled out. Resistivity and magnetoresistance properties have also been measured for all the samples.

Composites of magnetite (Fe3O4) nanoparticles dispersed in a polydimethylsiloxane (PDMS) matrix were prepared by a molding process. Two types of samples were obtained by free polymerization with randomly dispersed particles and by polymerization in an applied magnetic field. The magnetite nanoparticles were obtained from magnetic micrograins of acicular goethite (α-FeOOH) and spherical hematite (α-Fe2O3), as demonstrated by XRD measurements. The evaluation of morphological and compositional properties of the PDMS:Fe3O4 composites, performed by SEM and EDX, showed that the magnetic particles were uniformly distributed in the polymer matrix. Addition of magnetic dispersions promotes an increase of thermal conductivity compared with pristine PDMS, while further orienting the powders in a magnetic field during the polymerization process induces a decrease of the thermal conductivity compared with the un-oriented samples. The shape of the magnetic dispersions is an important factor, acicular dispersions providing a higher value for thermal conductivity compared with classic commercial powders with almost spherical shapes.

Context. The chromosphere is a partially ionized layer of the solar atmosphere that mediates the transition between the photosphere where the gas motion is determined by the gas pressure and the corona dominated by the magnetic field. Aims. We study the effect of partial ionization for 2D wave propagation in a gravitationally stratified, magnetized atmosphere characterized by properties that are similar to those of the solar chromosphere. Methods. We adopted an oblique uniform magnetic field in the plane of propagation with a strength that is suitable for a quiet sun region. The theoretical model we used is a single fluid magnetohydrodynamic approximation, where ion-neutral interaction is modeled by the ambipolar diffusion term. Magnetic energy can be converted into internal energy through the dissipation of the electric current produced by the drift between ions and neutrals. We used numerical simulations in which we continuously drove fast waves at the bottom of the atmosphere. The collisional coupling between ions and neutrals decreases with the decrease in the density and the ambipolar effect thus becomes important. Results. Fast waves excited at the base of the atmosphere reach the equipartition layer and are reflected or transmitted as slow waves. While the waves propagate through the atmosphere and the density drops, the waves steepen into shocks. Conclusions. The main effect of ambipolar diffusion is damping of the waves. We find that for the parameters chosen in this work, the ambipolar diffusion affects the fast wave before it is reflected, with damping being more pronounced for waves which are launched in a direction perpendicular to the magnetic field. Slow waves are less affected by ambipolar effects. The damping increases for shorter periods and greater magnetic field strengths. Small scales produced by the nonlinear effects and the superposition of different types of waves created at the equipartition height are efficiently damped by ambipolar diffusion.

Gastro-esophageal reflux disease (GERD) is a pathological entity in which the mixture of gastric contents (with low pH because of the high content of HCl acid) and biliary juice (rich in proteolytic enzymes like pepsin and trypsin) causes lesions on the mucosa lining the esophagus. A higher prevalence of GERD was discovered in patients who had a total laryngectomy. Concerning laryngectomies with tracheo-esophageal speaking valves, it has been demonstrated that GERD is an independent risk factor for failure of this method of speech rehabilitation. The authors performed an analysis of English language articles found following a search of the major medical scientific databases (NCBI®, EMBASE®, Cochrane®) containing the following keyword string: vocal prosthesis, total laryngectomy, GERD, acid reflux, tracheo-esophageal fistula, failure. Studies showed that exposure to the protelolytic enzymes from the reflux juice increases the diameter of the tracheo-esophageal fistula and permits local granulation tissue to form. Progressively, the increasing fistula diameter leads to complications ranging from microaspiration of liquids and saliva to speaking valve expulsion or ingestion and temporary incapacity of oral feeding. Medical therapy in the postoperative period as well as long-term (6 months or more) correction of GERD (PPI therapy, H2 blockers, prokinetics) is also demonstrated to reduce the complication rate in this category of patients. GERD has a high prevalence in the total laryngectomy population of patients and it has multiple etiologic factors. In patients with tracheoesophageal vocal prostheses, GERD causes an increase in the fistula diameter – with important consequences that affect the patient's quality of life - his ability to phonate and his ability to swallow. These complications come with added costs because of the need to more frequently change the vocal prostheses with ones increasing in diameter, as well as multiple hospitalizations (even surgery to recalibrate or close the tracheo-esophageal fistula). Recognizing and treating this condition therefore decreases the risk of complications following vocal prosthesis speech rehabilitation.

The influence of the partial substitution of Fe by Si and thermal treatments on the structural, magnetic and magnetostrictive properties of the Fe67.5Pd30.5Si2 rapidly solidified ribbons has been investigated. A remarkable decrease in the martensite transformation temperature, with ~ 65 K lower than that of the Fe–Pd archetype alloy, is observed in the as-prepared ribbons. The thermal treatments shift the martensite transformation temperatures upward, with approximately 13 K for the higher thermal treatment. Also, these induce an improvement in the crystallinity in these ribbons with high texture and an increase in the crystallite size as a result of reducing the internal defects and stress. The thermodynamic considerations discussed in the frame of the Clapeyron–Clausius relation by using the calorimetric and thermomagnetic measurements (up to 7 T) reveal a weak influence of the magnetic fields on the martensitic transformation temperatures (~ 0.5 K/T). The magnetostriction decrease with temperature under small magnetic fields was discussed, beside an unusual behaviour in the technically saturated domain. This behaviour is based on the coexistence of the ordinary and forced magnetostrictions, the last one increasing faster with the temperature decreasing.

In the absence of an initial seed, the Biermann battery term of a non-ideal induction equation acts as a source that generates weak magnetic fields. These fields are then amplified via a dynamo mechanism. The Kelvin-Helmholtz instability is a fluid phenomenon that takes place in many astrophysical scenarios and can trigger the action of the Biermann battery and dynamo processes. We aim to investigate the effect that the ionisation degree of the plasma and the interaction between the charged and neutral species have on the generation and amplification of magnetic fields during the different stages of the instability. We use the two-fluid model implemented in the numerical code Mancha-2F. We perform 2D simulations starting from a configuration with no initial magnetic field and which is unstable due to a velocity shear. We vary the ionisation degree of the plasma and we analyse the role that the different collisional terms included in the equations of the model play on the evolution of the instability and the generation of magnetic field. We find that when no collisional coupling is considered between the two fluids, the effect of the Biermann battery mechanism does not depend on the ionisation degree. However, when elastic collisions are taken into account, the generation of magnetic field is increased as the ionisation degree is reduced. This behaviour is slightly enhanced if the process of charge-exchange is also considered. We also find a dependence on the total density of the plasma related to the dependence on the coupling degree between the two fluids. As the total density is increased, the results from the two-fluid model converge to the predictions of single-fluid models., Comment: 20 pages, 13 figures, 2 movies. Accepted for publication in Astronomy & Astrophysics

The equimolar oxide mixture &beta, Ga2O3&mdash, &alpha, Fe2O3 was subjected to high-energy ball milling (HEBM) with the aim to obtain the nanoscaled GaFeO3 ortho-ferrite. X-ray diffraction, 57Fe M&ouml, ssbauer spectroscopy, and transmission electron microscopy were used to evidence the phase structure and evolution of the equimolar nano-system &beta, Fe2O3 under mechanochemical activation, either as-prepared or followed by subsequent calcination. The mechanical activation was performed for 2 h to 12 h in normal atmosphere. After 12 h of HEBM, only nanoscaled (~20 nm) gallium-doped &alpha, Fe2O3 was obtained. The GaFeO3 structure was obtained as single phase, merely after calcination at 950 &deg, C for a couple of hours, of the sample being subjected to HEBM for 12 h. This temperature is 450 &deg, C lower than used in the conventional solid phase reaction to obtain gallium orthoferrite. The optical and magnetic properties of representative nanoscaled samples, revealing their multifunctional character, were presented.

In this work, thermoelectric properties of the nanocomposite materials produced via ball milling followed by spark plasma sintering from In0.2Yb0.2Co4Sb12 double filled skutterudite (SKT) with silicon and tungsten carbide inclusions are investigated. The nanocomposites with low volume ratios of β-SiC and α-WC have a significantly increased power factor, while the lattice thermal conductivity is lowered only for β-SiC composites. The power factor enhancement in α-WC/SKT composite compensates the increase of its thermal conductivity, and as a consequence, the maximum value of the figure of merit, 0.97, is attained for 0.33 v% α-WC at 450 °C, with 15% higher than that of the simple skutterudite sample.

Objective Acute hematogenous osteomyelitis (AHO) has declining incidence in developed countries. AHO can cause rapid destruction of bone that can lead to functional impairment or even death if misdiagnosed and not treated urgently. In this study, we aimed to identify the main factors that may lead to a poor outcome and to establish a profile of patients with AHO who might have a negative outcome. Methods We conducted a retrospective single-center study including 94 patients with AHO, over a 10-year interval. Complete medical history including age at diagnosis, sex, socioeconomic status, symptoms, entry portal, pathogenic agent, location of infection, radiological features, treatment, and outcome were recorded. Results Male predominance was observed, with boys from rural areas more prone to a poor outcome. This is likely because they are more exposed to trauma and do not have proper access to emergency medical care. Staphylococcus aureus was the most common etiologic agent, with 84 patients testing positive. Disease evolution was toward chronicity in patients diagnosed late. The most frequent complications were sepsis and pathological fractures. Conclusions In our study, patients with negative outcomes were characterized by young age, repeated negative cultures, delayed surgery, rural residence, and male sex.

Solar prominences are formed by partially ionized plasma with inter-particle collision frequencies, which generally warrant magnetohydrodynamic treatment. In this work, we explore the dynamical impacts and observable signatures of two-fluid effects in the parameter regimes when ion-neutral collisions do not fully couple the neutral and charged fluids. We performed 2.5D two-fluid (charge – neutrals) simulations of the Rayleigh-Taylor instability (RTI) at a smoothly changing interface between a solar prominence thread and the corona. The purpose of this study is to deepen our understanding of the RTI and the effects of partial ionization on the development of the RTI using nonlinear two-fluid numerical simulations. Our two-fluid model takes into account viscosity, thermal conductivity, and collisional interaction between neutrals and charge: ionization or recombination, energy and momentum transfer, and frictional heating. In this paper, we explore the sensitivity of the RTI dynamics to the prominence equilibrium configuration, including the impact of the magnetic field strength and shear supporting the prominence thread, and the amount of prominence mass-loading. We show that at small scales, a realistically smooth prominence-corona interface leads to qualitatively different linear RTI evolution than that which is expected for a discontinuous interface, while magnetic field shear has the stabilizing effect of reducing the growth rate or eliminating the instability. In the nonlinear phase, we observe that in the presence of field shear the development of the instability leads to formation of coherent and interacting 2.5D magnetic structures, which, in turn, can lead to substantial plasma flow across magnetic field lines and associated decoupling of the fluid velocities of charged particles and neutrals.

For DEMO fusion reactor an expected heat flux of about 10 MW/m 2 should be extracted by the divertor which will have, most likely, an armour part made of W and a following heat sink part made of Cu or ODS Cu alloy. Unfortunately, for these materials the optimum operating temperature windows do not overlap. Thermal barrier materials are interface materials included in such components, aiming to keep the temperatures of both armour and heat sink parts in the corresponding operating windows, and to mitigate the effects of their different thermomechanical properties. Here we propose a simple spark plasma sintering route to create Cu-based composites with a high content (10–40 vol%) of various dispersed materials (Al or Y oxides, C, SiC), allowing a fine tuning of the content and a large pool of predefined shapes and dimensions. The resulting specimens can be further joined to armour and heatsink components via a similar electrical field assisted technology. Micro-structural and thermal properties are investigated for these materials allowing to select the most suited materials in view of their thermal conductivity and thermal expansion coefficients.

Solar prominences are formed by partially ionized plasma with inter-particle collision frequencies generally warranting magnetohydrodynamic treatment. In this work we explore the dynamical impacts and observable signatures of two-fluid effects in the parameter regimes when ion-neutral collisions do not fully couple the neutral and charged fluids. We perform 2.5D two-fluid (charges-neutrals) simulations of the Rayleigh-Taylor instability (RTI) at a smoothly changing interface between a solar prominence thread and the corona. The purpose of this study is to deepen our understanding of the RTI and the effects of the partial ionization on the development of RTI using nonlinear two-fluid numerical simulations. Our two-fluid model takes into account neutral viscosity, thermal conductivity, and collisional interaction between neutrals and charges: ionization–recombination, energy and momentum transfer, and frictional heating. In this paper, the sensitivity of the RTI dynamics to collisional effects for different magnetic field configurations supporting the prominence thread is explored. This is done by artificially varying, or eliminating, effects of both elastic and inelastic collisions by modifying the model equations. We find that ionization and recombination reactions between ionized and neutral fluids do not substantially impact the development of the primary RTI. However, such reactions can impact the development of secondary structures during the mixing of the cold prominence and hotter surrounding coronal material. We find that collisionality within and between ionized and neutral particle populations plays an important role in both linear and nonlinear development of RTI; ion-neutral collision frequency is the primary determining factor in development or damping of small-scale structures. We also observe that the degree and signatures of flow decoupling between ion and neutral fluids can depend on the inter-particle collisionality and on the magnetic field configuration of the prominence thread.

In this paper, we investigate the influence of Cu, Co, and Al substitutions on the transport properties, and in particular, the magnetoresistive effect in Ni–Fe–Ga ferromagnetic shape memory alloys (FSMAs) prepared as ribbons by melt spinning method and subjected to different thermal treatments. X-ray diffraction, differential scanning calorimetry, magnetometry, and magnetoresistive characterizations were performed. In the range of the martensitic transformation (MT), different FSMA compositions show a rich spectrum of different behaviors. For one of the compositions (Ni52Fe20Co2Ga23Al3), the magnetoresistance (MR) showed a local minimum or, on the contrary, a local maxima of reduced amplitude on cooling, in the range of the MT, depending on the performed thermal treatments. In the same composition, by replacing one Al atom with a Co one, no local extremes are seen, the alloy having a concomitant magneto-structural transition. When the magnetic field was varied, the MR showed a nonmonotonic variation in the martensite phase for some compounds, possibly due to the dynamics of the martensite variants realignment. From the studied compositions, the highest MR found on the MT of −9% for 5 T is for Ni50Fe20Ga27Cu3.

Solar chromosphere consists of a partially ionized plasma, which makes modeling the solar chromosphere a particularly challenging numerical task. Here we numerically model chromospheric waves using a two-fluid approach with a newly developed numerical code. The code solves two-fluid equations of conservation of mass, momentum, and energy, together with the induction equation for the case of the purely hydrogen plasma with collisional coupling between the charged and neutral fluid components. The implementation of a semi-implicit algorithm allows us to overcome the numerical stability constraints due to the stiff collisional terms. We test the code against analytical solutions of acoustic and Alfvén wave propagation in uniform medium in several regimes of collisional coupling. The results of our simulations are consistent with the analytical estimates, and with other results described in the literature. In the limit of a large collisional frequency, the waves propagate with a common speed of a single fluid. In the other limit of a vanishingly small collisional frequency, the Alfvén waves propagate with an Alfvén speed of the charged fluid only, while the perturbation in neutral fluid is very small. The acoustic waves in these limits propagate with the sound speed corresponding to either the charges or the neutrals, while the perturbation in the other fluid component is negligible. Otherwise, when the collision frequency is similar to the real part of the wave frequency, the interaction between charges and neutrals through momentum-transfer collisions cause alterations of the waves frequencies and damping of the wave amplitudes.

In the case of DEMO fusion reactor, the divertor should be able to extract a steady heat flux of about 10 MW/m2. A promising concept is the W-monoblock which should be connected to a CuCrZr or an advanced Cu ODS alloy pipe passing through the W component. Taking into account the optimum operating temperature windows for W and existing Cu-based alloys and the thermal expansion coefficients mismatch of these two materials, a “thermal barrier” interface material is inserted in between in order to mitigate the thermal stresses and to optimize the heat flow through divertor components. In this work we investigate the feasibility to realize such divertor components using materials produced by FAST (field assisted sintering technology). This powder metallurgy technique was used firstly to produce W or W-based composites and the thermal barriers in an almost final shape and then to join the materials in realistic divertor mock-ups. The thermal barrier materials are various Cu-based composites which are included both as single material or as functionally graded components. The interface quality between different materials is investigated by scanning electron microscopy and the heat flow through components is evaluated using simulations.

Fibular hemimelia is a rare congenital malformation, but one of the most common long-bone length deficiencies, without a clearly known cause. It can occur as an isolated anomaly or as part of a malformation syndrome. The presentation may vary from mild fibular hypoplasia to fibular absence. We reviewed the case of a 4 year old male who referred to our clinic at the age of one year, presenting with leg length discrepancy, bowed leg and with an absence of the peroneal malleolus, the fifth toe and equinovalgus deformity. After further investigations and presenting the family the treatment options, they ruled out amputation and surgical treatment was started with two circumferential periosteal releases followed by a telescopic rod implant and an Ilizarov frame fixator. The purpose of the present report is to highlight the good outcomes of combining the telescopic rod and Ilizarov frame fixator in complete fibular hemimelia.

The effect of “in situ” thermal treatments (by DSC measurements) on the martensitic transformation in two representative Ni-Fe-Ga and Ni-Mn-Ga alloys has been studied and discussed by correlating the structural and magnetic properties. The alloys were prepared from high purity elements, by arc melting under argon protective atmosphere as bulk and also as melt-spun ribbons - an alternative preparation route that also allows to assess the influences of grains size and strain induced by this processing method. All samples presented reversible thermo-elastic transformations. The thermal treatments promote a reduction of the martensitic transformation temperatures in the Ni-Fe-Ga investigated samples, as opposed to the stoichiometric Ni2MnGa where the temperatures increase with increasing the annealing temperatures. Interestingly however, the off-stoichiometric Ni-Mn-Ga with increased Ni content recovers the behaviour with reduction of transformation temperatures by thermal treatments. The precipitation of the secondary FCC (γ) phase is inherently found in Ni-Fe-Ga alloys with Ga ≤ 27% at, and also -although in lower amounts- in the off-stoichiometric Ni-Mn-Ga. The γ phase is considered to contribute to the decrease of the MT temperatures (via valence electrons concentration depletion of the main matrix) and of the transformation heat as well as to the final structural degradation if the temperature of the thermal treatments is further increased. In addition, this phase, located mainly at the grain boundaries, is responsible for the improved ductility of Ni-Fe-Ga based alloys. Changes in the transformation heat due to thermal treatments are observed and discussed in both types of alloys, the maxima of the transformation heat being associated with the highest atomic order. Thermo-magnetic measurements show that Ni-Fe-Ga alloys have close magnetic and structural transitions temperatures, with promising applications for magnetic refrigeration.

The influence of the heat treatments on the martensitic transformation, magnetic properties and thermo- and magnetic induced strain on Ni50Fe20Ga27Cu3 ferromagnetic shape memory alloy prepared as ribbons by melt–spinning technique are investigated. The degree of atomic order as effect of different thermal treatments produces important changes in the magneto-crystalline anisotropy of the martensite phase. The anomalies evidenced in the thermo-and magnetic- strain curves are discussed and correlated with the thermo-magnetic data. The transformation-induced strains with and without magnetic field have been measured, the results setting out the influence of the pre-martensitic transformation.

In this paper, we present a modeling framework suited for the theoretical study of electrolyte-gated organic thin-film transistors. Employing a novel, fully self-consistent, coupled Poisson–Boltzmann/drift-diffusion simulator, we analyze the response of biosensors for varying bias conditions and ion concentrations in the electrolyte. Our model considers the diffusive nature of ions in the electrolyte region, the formation of a Helmholtz layer at the electrolyte/organic semiconductor interface and the particular charge transport mechanisms of organic semiconductors, such as field-dependent mobility and the presence of defect states. We calibrate our model on a set of current–voltage measurements for a fabricated device. Once validated, our simulation model offers useful insights in the underlying physics and helps us quantify the impact of the electrolyte solution on the surface potential at the electrolyte/semiconductor interface. A sensitivity analysis is performed to determine the inaccuracy of simpler models, such as the Helmholtz approximation, on the response of our biosensor. Improving our understanding of the working principle and charge transport in such novel electrolyte-gated Organic Thin Film Transistors is an indispensable step toward performance optimization and can pave the way for the design of new, more sensitive biosensor devices.

Specific functional characteristics of the ferromagnetic shape memory alloy Fe67.5Pd30.5Ga2 prepared as ribbons by rapid quenching technique are reported. The shift of the martensitic transformation temperature induced by the applied magnetic field was determined from the thermomagnetic measurements at various fields up to 5T being proved to be in good agreement with the result obtained from calorimetric data via the Clapeyron - Claussius relation. Magnetostriction measurements reveal a pure spin rotation mechanism under low applied magnetic fields, allowed by the reduced magnetic anisotropy. In high magnetic fields and at temperatures close to martensitic transformation, the magnetostriction has a linear increase up to the maximum considered magnetic induction of 3T. This behavior has been discussed in connection with the forced magnetostiction aspects.

Waves and shocks traveling through the solar chromospheric plasma are influenced by its partial ionization and weak collisional coupling, and may become susceptible to multi-fluid effects, similar to interstellar shock waves. In this study, we consider fast magneto-acoustic shock wave formation and propagation in a stratified medium, that is permeated by a horizontal magnetic field, with properties similar to that of the solar chromosphere. The evolution of plasma and neutrals is modeled using a two-fluid code that evolves a set of coupled equations for two separate fluids. We observed that waves in neutrals and plasma, initially coupled at the upper photosphere, become uncoupled at higher heights in the chromosphere. This decoupling can be a consequence of either the characteristic spatial scale at the shock front, that becomes similar to the collisional scale, or the change in the relation between the wave frequency, ion cyclotron frequency, and the collisional frequency with height. The decoupling height is a sensitive function of the wave frequency, wave amplitude, and the magnetic field strength. We observed that decoupling causes damping of waves and an increase in the background temperature due to the frictional heating. The comparison between analytical and numerical results allows us to separate the role of the nonlinear effects from the linear ones on the decoupling and damping of waves.