Enhanced magnetocaloric response in Cr/Mo containing Nanoperm-type amorphous alloys

The magnetocaloric effect of Fe76Cr8−xMoxCu1B15 (x =0,4) alloys is studied. Although the combined addition of Cr and Mo is more efficient in tuning the Curie temperature of the alloy, the Mo-free alloy presents a higher magnetocaloric response. The refrigerant capacity (RC) for the Mo-containing alloy is comparable to that of Gd5Ge1.9Si2Fe0.1 (for a field of 50 kOe, RC = 273 J kg−1 for the Mo alloy vs 240 J kg−1 for the Gd-based one), with a larger temperature span of the optimal refrigeration cycle (250 K vs 90 K, respectively). The restriction of the temperature span to 90 K gives RC = 187 J kg−1 for the Mo alloy. A master curve behavior for the magnetic entropy change is also evidenced

Thermomagnetic detection of recrystallization in FeCoNbBCu nanocrystalline alloys

The recrystallization process in FeCoNbBCu nanocrystallinealloys is evidenced from thermomagnetic results as a significant decrease in magnetization at the second crystallization stage. The lowering in the volume fraction of α-FeCo crystals indicates that some of these crystals contribute to the boride phases formed. Electron microscopy images reveal that the final microstructure consists of large crystals (∼500 nm) of a fcc (FeCo)23B6(FeCo)23B6 phase and small crystals (∼20 nm) of bcc α-FeCo and of some boride phases as such (FeCo)2B

Magnetic permeability of ( Fe Co Ge ) 88 Zr 6 B 5 Cu 1 alloys: Thermal stability in a wide temperature range.

Temperature dependence, from room temperature up to 1000 K, of the initial permeability of Fe83−xCoxGe5Zr6B5Cu1 x=5 and 20 alloys at different stages of devitrification is reported. As nanocrystallization progresses, room temperature decreases but high temperature one increases, leading to an improvement of its thermal stability extended from room temperature up to 915 K, characterized by a temperature coefficient of permeability 0.1%/K 4000 and 0.04%/K 800 for 5 and 20 at. % Co containing alloys, respectively

Detection of the onset of nanocrystallization by calorimetric and magnetic measurements

It is generally accepted that measurements of the magnetic properties are more sensitive than measurements of the enthalpy changes in the detection of the onset of crystallization of ferromagnetic phases emerging from a paramagnetic amorphous alloy. In this work, it is shown that the formation of a very fine nanocrystalline microstructure can make this assumption incorrect. Under some circumstances, the nanocrystallization onset temperature obtained from magnetic techniques is higher than the one obtained from enthalpy changes. The phenomenon is explained in terms of the superparamagnetic behavior of the uncoupled nanocrystals at the very early stages of nanocrystallizatio

The thickness of a liquid layer on the free surface of ice as obtained from computer simulation

Molecular dynamic simulations were performed for ice Ih with a free surface by using four water models, SPC/E, TIP4P, TIP4P/Ice and TIP4P/2005. The behavior of the basal plane, the primary prismatic plane and of the secondary prismatic plane when exposed to vacuum was analyzed. We observe the formation of a thin liquid layer at the ice surface at temperatures below the melting point for all models and the three planes considered. For a given plane it was found that the thickness of a liquid layer was similar for different water models, when the comparison is made at the same undercooling with respect to the melting point of the model. The liquid layer thickness is found to increase with temperature. For a fixed temperature it was found that the thickness of the liquid layer decreases in the following order: the basal plane, the primary prismatic plane, and the secondary prismatic plane. For the TIP4P/Ice model, a model reproducing the experimental value of the melting temperature of ice, the first clear indication of the formation of a liquid layer appears at about -100 Celsius for the basal plane, at about -80 Celsius for the primary prismatic plane and at about -70 Celsius for the secondary prismatic plane.Comment: 41 pages and 13 figure

12-Year-Old Female with Mucocutaneous Lesions

info:eu-repo/semantics/publishedVersio

The Holographic Dual of 2+1 Dimensional QFTs with N=1 SUSY and Massive Fundamental Flavours

The Maldacena Nastase solution is generalised to include massive fundamental matter through the addition of a flavour profile. This gives a holographic dual to N=1 SYM-CS with massive fundamental matter with a singularity free IR. We study this solution in some detail confirming confinement and asymptotic freedom. A recently proposed solution generating technique is then applied which results in a new type-IIA supergravity solution. In a certain limit the geometry of this solution is asymptotically AdS_4X Y, where Y is the metric at the base of the Bryant-Salamon G_2 cone, which has topology S^3XS^3.Comment: 31 pages plus appendices, 6 figures. v3: Typos corrected, version to appear in JHE

Pregnancy after Gastric Banding for the Treatment of Morbid Obesity

Obesity is known to have a negative impact on pregnancy outcome, as it is associated with an increase in the incidence of gestational diabetes, hypertension, preeclampsia, neural tube defects, macrosomia, and late fetal death. Gastric banding is considered an appropriate intervention for morbid obesity when other weight-loss measures are unsuccessful, and this treatment has been shown to be effective in causing a sustainable weight loss. Some women will become pregnant after bariatric surgery, and the nutritional and metabolic challenges brought by gastric banding may have a profound impact on maternal health and pregnancy outcome. The authors report the case of a 27 year old pregnant woman, with a past medical history of gastric banding surgery for morbid obesity. At 18 weeks of gestation, the patient started complaining of severe nausea and vomiting, The situation deteriorated three weeks later when she rapidly developed severe desnutrition, dehydration and early signs of liver and renal failure. Migration of the gastric band was diagnosed, and laparoscopy conducted to remove it. In the day following surgery the patient complained of absent fetal movements, and an intrauterine demise was diagnosed on ultrasound. Pathological examination of the fetus and placenta failed to reveal the cause of death, but no growth restriction was documented, suggesting the occurrence of an acute event