Phase diagram of the XXZ ferrimagnetic spin-(1/2, 1) chain in the presence of transverse magnetic field

We investigate the phase diagram of an anisotropic ferrimagnet spin-(1/2, 1) in the presence of a non-commuting (transverse) magnetic field. We find a magnetization plateau for the isotropic case while there is no plateau for the anisotropic ferrimagnet. The magnetization plateau can appear only when the Hamiltonian has the U(1) symmetry in the presence of the magnetic field. The anisotropic model is driven by the magnetic field from the N\'{e}el phase for low fields to the spin-flop phase for intermediate fields and then to the paramagnetic phase for high fields. We find the quantum critical points and their dependence on the anisotropy of the aforementioned field-induced quantum phase transitions. The spin-flop phase corresponds to the spontaneous breaking of Z2 symmetry. We use the numerical density matrix renormalization group and analytic spin wave theory to find the phase diagram of the model. The energy gap, sublattice magnetization, and total magnetization parallel and perpendicular to the magnetic field are also calculated. The elementary excitation spectrums of the model are obtained via the spin wave theory in the three different regimes depending on the strength of the magnetic field.Comment: 14 pages, 11 eps figure

Influence of anodizing process on fatigue life of a machined aluminium alloy

In order to investigate the coupled effects of machining and anodizing processes on fatigue life of alloy 7010-T7451, a series of rotating bending fatigue tests were conducted at 60Hz. In the as machined condition, test results showed that fatigue life is surface roughness dependent and that fatigue life decreases with an increase in surface roughness and this effect is found to be more pronounced in high cycle fatigue where major portion of fatigue life is consumed in nucleating the cracks. Effects of pretreatments, like degreasing and pickling employed prior to anodizing, on fatigue life of the given alloy were also studied. Results demonstrated that degreasing showed no change in fatigue life while pickling had negative impact on fatigue life of specimens. The small decrease in fatigue life of anodized specimens as compare to pickled specimens is attributed to brittle and microcracking of the coating. Scanning electron microscopic (SEM) examination revealed multi-site crack initiation for the pickled and anodized specimens. SEM examination showed that pickling solution attacked the grain boundaries and intermetallic inclusions present on the surface resulting in pits formation. These pits are of primary concern with respect to accelerated fatigue crack nucleation and subsequent anodized coating formation

Pathways to Success

__Abstract__ Policy Brief Pathways to Success Mei 2013 Eindrapportage van het Pathways to Success project. Eén van de opvallendste conclusies uit het rapport is de enorme van inzet onder de overgrote meerderheid van hoog opgeleide jongeren van de tweede generatie voor andere (meestal jongere) jongeren. Deze inzet varieert van praktische ondersteuning bij huiswerk tot advies bij studie- en loopbaankeuzes, netwerkvaardigheden en strategiën die je nodig hebt om succesvol te zijn in het onderwijs en op de arbeidsmarkt. Die inzet is nu nog grotendeels verborgen, maar zeer belangrijk kapitaal voor de stad. Tegelijkertijd geven de geinterviewden aan zelf ook op verschillende momenten hulp en coaching hebben ontvangen van mensen uit hun eigen omgeving of op school of in het zoeken naar een baan. Die keten van hulp geven en coaching ontvangen om je zelf verder te onwikkelen loopt als een rode lijn door het rapport

Simple Rules for Climate Policy and Integrated Assessment

A simple integrated assessment framework that gives rules for the optimal carbon price, transition to the carbon-free era and stranded carbon assets is presented, which highlights the ethical, economic, geophysical and political drivers of optimal climate policy. For the ethics we discuss the role of intergenerational inequality aversion and the discount rate, where we show the importance of lower discount rates for appraisal of longer run benefit and of policy makers using lower discount rates than private agents. The economics depends on the costs and rates of technical progress in production of fossil fuel, its substitute renewable energies and sequestration. The geophysics depends on the permanent and transient components of atmospheric carbon and the relatively fast temperature response, and we allow for positive feedbacks. The politics stems from international free-rider problems in absence of a global climate deal. We show how results change if different assumptions are made about each of the drivers of climate policy. Our main objective is to offer an easy back-on-the-envelope analysis, which can be used for teaching and communication with policy makers

Temperature measurement on neurological pulse generators during MR scans

According to manufacturers of both magnetic resonance imaging (MRI) machines, and implantable neurological pulse generators (IPGs), MRI is contraindicated for patients with IPGs. A major argument for this restriction is the risk to induce heat in the leads due to the electromagnetic field, which could be dangerous for the surrounding brain parenchyma. The temperature change on the surface of the case of an ITREL-III (Medtronic Inc., Minneapolis, MN) and the lead tip during MRI was determined. An anatomical realistic and a cubic phantom, filled with phantom material mimicking human tissue, and a typical lead configuration were used to imitate a patient who carries an IPG for deep brain stimulation. The measurements were performed in a 1.5 T and a 3.0 T MRI. 2.1°C temperature increases at the lead tip uncovered the lead tip as the most critical part concerning heating problems in IPGs. Temperature increases in other locations were low compared to the one at the lead tip. The measured temperature increase of 2.1°C can not be considered as harmful to the patient. Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures

Improvement Least-Distance Measure Model with Coplanar DMU on Strong Hyperplanes

Technique of Data Envelopment Analysis (DEA) involves methods conducted for desirable objective management of Decision Making Unit (DMU) that is same increasing of efficiency level. Data envelopment analysis furthermore determines the efficiency level, provides situation, removes inefficiency with evaluated benchmarking information. In this paper the use of the improvement Least-Distance measure with relation previous model by coplanar DMU, is proposed for computational dissipation at assess distance on these interior combinations, for determination the shortest projection from a considered unit to the strongly efficient production frontier. Therefore locate nearest path to improvement efficiency the evaluated DMU

The promising applications of ultrasound in emergency medicine and critical care related to in cancer: A review

The referral of critically ill cancer patients to an Intensive Care Unit (ICU) is a matter of controversial debate. During the past decade, ultrasound imaging performed by emergency physicians and critical care providers has gained significant clinical importance. A number of researches reported the ability of emergency physicians and critical care providers to carry out and interpret bedside assessments exactly, along with a great effect on the quality of care. It is possible assessing ultrasound-mediated subjects who are very much instable to be evaluated through alternative imaging methods. Furthermore, ultrasound in the emergency medicine and critical care open a new way towards facilitate diagnosis, simplify rapid dispositions, and influence management decisions. The primarily perspective of bedside ultrasound by emergency physicians and critical care providers was limited to a few applications. However, it was observed a number of new applications due to the universal and extensive adaptation of ultrasound in emergency uses. In this review, we discussed the promising applications of ultrasound for emergency medicine and critical care that encompass telemedicine, prehospital setting, soft tissue, fractures, ocular, paracentesis, pneumothorax, foreign bodies, bladder and arthrocentesis ultrasound. © Oncology and Radiotherapy

Structural Attributes and Photodynamics of Visible Spectrum Quantum Emitters in Hexagonal Boron Nitride

Newly discovered van der Waals materials like MoS2, WSe2, hexagonal boron nitride (h-BN), and recently C2N have sparked intensive research to unveil the quantum behavior associated with their 2D structure. Of great interest are 2D materials that host single quantum emitters. h-BN, with a band gap of 5.95 eV, has been shown to host single quantum emitters which are stable at room temperature in the UV and visible spectral range. In this paper we investigate correlations between h-BN structural features and emitter location from bulk down to the monolayer at room temperature. We demonstrate that chemical etching and ion irradiation can generate emitters in h-BN. We analyze the emitters' spectral features and show that they are dominated by the interaction of their electronic transition with a single Raman active mode of h-BN. Photodynamics analysis reveals diverse rates between the electronic states of the emitter. The emitters show excellent photo stability even under ambient conditions and in monolayers. Comparing the excitation polarization between different emitters unveils a connection between defect orientation and the h-BN hexagonal structure. The sharp spectral features, color diversity, room-temperature stability, long-lived metastable states, ease of fabrication, proximity of the emitters to the environment, outstanding chemical stability, and biocompatibility of h-BN provide a completely new class of systems that can be used for sensing and quantum photonics applications