345 research outputs found
Magnetic properties in amorphous Co95xDyxZr5 thin films
Amorphous Co95-xDyxZr5 thin films were prepared by RF sputtering and their magnetic properties were studied as a function of temperature and for the composition range 0<x<30. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. The magnetic phase diagrams are presented.Amorphous Co95-xDyxZr5 thin films were prepared by RF sputtering and their magnetic properties were studied as a function of temperature and for the composition range 0<x<30. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. The magnetic phase diagrams are presented
Magnetic studies of amorphous Fe-Dy-B ribbons
We have studied the magnetization of melt spun amorphous Fe80−xDyxB20 alloys with 0 ≤ x ≤ 7.5 under magnetic fields up to 6T, and have analyzed the results at 4.2 K on the basis of the random magnetic anisotropy model. Exchange constant and local random anisotropy KL were evaluated. Using the Sarkis´s model, the local anisotropies per atom are found to be 1.75 107 and 4 107 erg/cm3 for Fe and Dy, respectively.We have studied the magnetization of melt spun amorphous Fe80−xDyxB20 alloys with 0 ≤ x ≤ 7.5 under magnetic fields up to 6T, and have analyzed the results at 4.2 K on the basis of the random magnetic anisotropy model. Exchange constant and local random anisotropy KL were evaluated. Using the Sarkis´s model, the local anisotropies per atom are found to be 1.75 107 and 4 107 erg/cm3 for Fe and Dy, respectively
The determination of moisture sorption isotherms and the isosteric heat of sorption for irradiated and non-irradiated durum wheat
Durum Wheat is deemed as one of the most important agricultural elements in the food system. Gamma irradiation treatment proves to be an efficient technique to decontaminate cereals so that we can ensure their hygienic quality during conservation. This paper seeks to study the hygroscopic behavior of irradiated and non-irradiated durum wheat at three temperatures 30 °C, 40 °C and 50 °C using the static gravimetric method. Furthermore, modeling the relationship between water activity and the equilibrium moisture content has been conducted through several models. GAB and Halsey were selected as convenient models that represent moisture sorption isotherms data for durum wheat. The net isosteric heat of sorption, the specific surface area of sorption was calculated via several equations including the Marquardt–Levenberg algorithm. As a result, the study of the samples reveals that the ionization at a low dose affects the moisture sorption of durum whea
Thrombose de la veine ovarienne au post-partum, révélée par un syndrome appendiculaire: à propos d’un cas
Une patiente de 27 ans a présenté à J13 du post partum, suite à un accouchement eutocique non compliqué et sans anamnèse infectieuse, une douleur en fosse iliaque droite évoluant dans un contexte fébrile. Devant une suspicion clinique et biologique d'appendicite, nous avons réalisé une échographie abdominopelvienne qui était normale. Le complément par scanner abdominale, a objectivé une thrombose de la veine ovarienne (TVO) à droite remontant jusqu'à la veine cave inférieure. Le traitement médical était basé essentiellement sur les anticoagulants. L'évolution était favorable
Extracción de aceite de orujo de aceituna con hexano ácido
The use of acidic hexane as a solvent increases the extracted oil yield from olive foot cake.
Two extraction procedures are studied: open air extraction at room temperature and Soxhlet exhaustive extraction.
The additional yield is about 5% for a 2.5% acetic acid content in case of open air extraction and turns out to be 9% for 7.5% acetic acid content in the Soxhlet procedure. An analysis of the extracted oil shows a light increase of the acidity of oil. The improved yield may be attributed to the action of acetic acid on the decomposition of intercellular structures and binding of some polar lipids. The phospholipids content of oil extracted with 7.5% acidic hexane is found to be 25 times more than with pure hexane.El uso de hexano ácido como disolvente aumenta el rendimiento de aceite extraído de orujo de aceituna.
Se han estudiado dos procedimientos de extracción: extracción al aire libre a temperatura ambiente y extracción exhaustiva en Soxhlet.
En el caso de extracción al aire libre el rendimiento adicional es alrededor del 5% para un contenido del 2'5% en ácido acético y llega a ser en el procedimiento en Soxhlet del 9% para un contenido en ácido acético del 7'5%. Un análisis del aceite extraído mostró un ligero aumento de la acidez del aceite. La mejora del rendimiento puede ser atribuida a la acción del ácido acético sobre la descomposición de estructuras intercelulares y uniones de lípidos polares. Se ha encontrado que el contenido en fosfolípidos del aceite extraído con el 7*5% de hexano ácido es 25 veces mayor que con hexano puro
Chemical synthesis and magnetic properties of monodisperse cobalt ferrite nanoparticles
In this work, a successful synthesis of magnetic cobalt ferrite (CoFe2O4)
nanoparticles is presented. The synthesized CoFe2O4 nanoparticles have a
spherical shape and highly monodisperse in the selected solvent. The effect of
different reaction conditions such as temperature, reaction time and varying
capping agents on the phase and morphology is studied. Scanning transmission
electron microscopy showed that the size of these nanoparticles can be
controlled by varying reaction conditions. Both X-ray diffraction and energy
dispersive X-ray spectroscopy corroborate the formation of CoFe2O4 spinel
structure with cubic symmetry. Due to optimized reaction parameters, each
nanoparticle was shown to be a single magnetic domain with diameter ranges from
6 to 16 nm. Finally, the magnetic investigations showed that the obtained
nanoparticles are superparamagnetic with a small coercivity value of about 315
Oe and a saturation magnetization of 58 emu/g at room temperature. These
results make the cobalt ferrite nanoparticles promising for advanced magnetic
nanodevices and biomagnetic applications.Comment: 10 pages, 9 figure
Pneumonia Recovery; Discrepancies in Perspectives of the Radiologist, Physician and Patient
BACKGROUND: Chest radiographs are often used to diagnose community-acquired pneumonia (CAP), to monitor response to treatment and to ensure complete resolution of pneumonia. However, radiological exams may not reflect the actual clinical condition of the patient. OBJECTIVE: To compare the radiographic resolution of mild to moderately severe CAP to resolution of clinical symptoms as assessed by the physician or rated by the patient. DESIGN: Prospective cohort study. PARTICIPANTS: One hundred nineteen patients admitted because of mild to moderately severe CAP with new pulmonary opacities. MAIN MEASURES: Radiographic resolution and clinical cure of CAP were determined at day 10 and 28. Radiographic resolution was defined as the absence of infection-related abnormalities; clinical cure was rated by the physician and defined by improvement of signs and symptoms. In addition, the CAP score, a patient-based symptom score, was calculated. KEY RESULTS: Radiographic resolution, clinical cure and normalization of the CAP score were observed in 30.8%, 93% and 32% of patients at day 10, and in 68.4%, 88.9% and 41.7% at day 28, respectively. More severe CAP (PSI score >90) was independently associated with delayed radiographic resolution at day 28 (OR 4.7, 95% CI 1.3-16.9). All 12 patients with deterioration of radiographic findings during follow-up had clinical evidence of treatment failure. CONCLUSIONS: In mild to moderately severe CAP, resolution of radiographic abnormalities and resolution of symptoms scored by the patient lag behind clinical cure assessed by physicians. Monitoring a favorable disease process by routine follow-up chest radiographs seems to have no additional value above following a patient's clinical cours
Cas rare de dysphagie révélant une Achalasie de l’œsophage
Le mégaoesophage ou achalasie reste une affection rare sous nos cieux. Ce travail rapporte un cas de dysphagie aigue admis aux urgences révélant un mégaoesophage idiopathique. Le but de cette observation est d’élaborer une démarche diagnostic devant toute dysphagie et de savoir mettre en oeuvre les examens complémentaires pour la confirmer ainsi que les différentes possibilités thérapeutiques qui s’offrent à nous pour traiter cette pathologie rare
Prise en charge du Cancer de la Vulve
Le cancer de la vulve est relativement rare. Son étiopathogénie est actuellement mieux élucidée. Sa prise en charge, essentiellement chirurgicale, a évolué vers une approche conservatrice grâce aux résections limitées et à la lymphadénectomie sélective qui a permis de réduire considérablement la morbidité et les séquelles chirurgicales sans pour autant altérer le pronostic. La prise en charge du cancer de la vulve doit être multidisciplinaire incluant une chirurgie minimale invasive dans les stades précoces et une radio-chimiothérapie : préopératoires dans les stades localement avancés, en adjuvant en cas de facteurs de risque de rechute et en palliatif dans les formes inopérables. La prévention repose sur le traitement des lésions précancéreuses et la vaccination anti HPV
The correlation of RNase A enzymatic activity with the changes in the distance between Nepsilon2-His12 and N delta1-His119 upon addition of stabilizing and destabilizing salts.
The effect of stabilizing and destabilizing salts on the catalytic behavior of ribonuclease A (RNase A) was investigated at pH 7.5 and 25 degrees C, using spectrophotometric, viscometric and molecular dynamic methods. The changes in the distance between N(epsilon2) of His(12) and N(delta1) of His(119) at the catalytic center of RNase A upon the addition of sodium sulfate, sodium hydrogen sulfate and sodium thiocyanate were evaluated by molecular dynamic methods. The compactness and expansion in terms of Stokes radius of RNase A upon the addition of sulfate ions as kosmotropic salts, and thiocyanate ion as a chaotropic salt, were estimated by viscometric measurements. Enzyme activity was measured using cytidine 2', 3'-cyclic monophosphate as a substrate. The results from the measurements of distances between N(epsilon2) of His(12) and N(delta1) of His(119) and Stokes radius suggest (i) that the presence of sulfate ions decreases the distance between the catalytic His residues and increases the globular compactness, and (ii) that there is an expansion of the enzyme surface as well as elongation of the catalytic center in the presence of thiocyanate ion. These findings are in agreement with activity measurements
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