Cancellation of probe effects in measurements of spin polarized momentum density by electron positron annihilation

Measurements of the two dimensional angular correlation of the electron-positron annihilation radiation have been done in the past to detect the momentum spin density and the Fermi surface. We point out that the momentum spin density and the Fermi Surface of ferromagnetic metals can be revealed within great detail owing to the large cancellation of the electron-positron matrix elements which in paramagnetic multiatomic systems plague the interpretation of the experiments. We prove our conjecture by calculating the momentum spin density and the Fermi surface of the half metal CrO2, who has received large attention due to its possible applications as spintronics material

Theoretical Study on Coexistence of Ferromagnetism and Superconductivity

On the basis of a two-dimensional t-t' Hubbard model in ferromagnetic and paramagnetic states, the triplet superconducting mechanism is investigated by the third-order perturbation theory with respect to the on-site Coulomb interaction U. In general, the superconducting state is more stable in the paramagnetic state than in the ferromagnetic state. As a special case, the dominant ferromagnetic superconductivity is obtained by the electron-electron correlation between the electronlike majority and holelike minority bands. Furthermore, it is pointed out that in some cases the two bands play an essential role for the coexistence of superconductivity and ferromagnetism.Comment: 5 pages, 10 figure

Independent Work Placements As A Getway To The World Of Work

Small to Medium-sized Enterprises (SMEs), a wide range of other languages are used. Every language is an asset. The most commonly spoken languages across enterprises of all sizes in the UK are French, German and Spanish, the ..

The dual nature of 5f electrons and origin of heavy fermions in U compounds

We develop a theory for the electronic excitations in UPt$_3$ which is based on the localization of two of the $5f$ electrons. The remaining $f$ electron is delocalized and acquires a large effective mass by inducing intra-atomic excitations of the localized ones. The measured deHaas-vanAlphen frequencies of the heavy quasiparticles are explained as well as their anisotropic heavy mass. A model calculation for a small cluster reveals why only the largest of the different $5f$ hopping matrix elements is operative causing the electrons in other orbitals to localize.Comment: 6 pages, 3 figure

Distance as a barrier to cancer diagnosis and treatment: Review of the literature

The burden of travel from a patient’s residence to health care providers is an important issue that can influence access to diagnosis and treatment ofcancer.Although several studies have shown that the travel burden can result in delays in diagnosis and treatment of many common cancers, its role appears underestimated in the treatment of patients in clinical practice. Therefore, we performed a review of the published data on the role of travel burden influencing four items: delay of diagnosis, adequate treatment of cancer, outcome, and quality of life of cancer patients. Forty-seven studies published up to December 2014 were initially identified. Twenty studies were excluded because they did not regard specifically the four items of our review.Twenty-seven studies formed the basis of our study and involved 716,153 patients. The associations between travel burden and (a) cancer stage at diagnosis (12 studies), (b) appropriate treatment (8 studies), (c) outcome (4 studies), and (d) quality of life (1 study) are reported. In addition, in two studies,therelationbetween travel burden and compliance with treatment was examined. The results of our review show that increasing travel requirements are associated with more advanced disease at diagnosis, inappropriatetreatment, aworse prognosis, and a worse quality of life. These results suggest that clinical oncologists should remember the specific travel burden problem for cancer patients, who often need health care services every week or every month for many years

Positron-electron autocorrelation function study of E-center in silicon

A study was conducted on the positron-electron autocorrelation function of defect center in silicon. The positron annihilation lifetime spectroscopy (PALS) spectra taken on the as-grown and defected samples of silicon were studied. It was found that the positron binding energy to the defect could be estimated from the ratio of the positron-electron autocorrelates for bulk crystal and defect trapped positron states.published_or_final_versio

Parental Distress and Affective Perception of Hospital Environment after a Pictorial Intervention in a Neonatal Intensive Care Unit

Pictorial humanization is a useful intervention for the improvement of hospitalized patients' affective states. Despite benefits in many hospital wards having been well documented, so far, no attention was paid to the Neonatal Intensive Care Unit (NICU). The aim of the present study was to evaluate the levels of distress and the affective perception of the environment experienced by parents of infants hospitalized in a NICU after the implementation of an intervention of pictorial humanization. A sample of 48 parents was recruited, 25 before the intervention was performed (Control Group), and 23 after its implementation (Pictorial Humanization Group). All parents completed the "Rapid Stress Assessment Scale" and "Scales of the Affective Quality Attributed to Place" questionnaires. Despite results showing no significant differences on parental distress, after implementation of pictorial intervention parents reported a perception of the NICU as significantly more pleasant, exciting, and arousing, and less distressing, unpleasant, gloomy, and sleepy. A higher level of distress and a perception of the environment as less relaxing was predicted for the Control Group condition. The present study suggests that the pictorial intervention represents a useful technique to create more welcoming hospital environments and to reduce the negative effects associated with infant hospitalization

THE REALIZATION OF A NEW GEOMAGNETIC OBSERVATORY IN CENTRAL ITALY, REPLACING L'AQUILA GEOMAGNETIC OBSERVATORY

The geomagnetic Observatory of L'Aquila was founded by Istituto Nazionale di Geofisica e Vulcanologia (INGV) in 1958, on the occasion of the International Geophysical Year. It is the main Italian geomagnetic observatory and since 1999 is part of the Intermagnet network. In 2009 L’Aquila was struck by a strong earthquake; the town was seriously damaged, and since then many activities moved to the suburbs; close to the Geomagnetic Observatory new activities were planned. Then the necessity to find in the surroundings a new place, suitable for the installation of a Geomagnetic Observatory, arose. Several tests were made and a possible location was found in Castel Del Monte, 40km from L’Aquila; a preliminary analysis of the electromagnetic background noise and of the spatial magnetic field gradients has shown that the place can meet the requirements for a Geomagnetic Observatory. Meanwhile, in 2010, a new Geomagnetic Observatory was installed in Duronia, 130 km South-East from L’Aquila and since 2012 it is part of the Intermagnet network