Towards a Rigorous Proof of Magnetism on the Edges of Graphene Nano-ribbons

A zigzag edge of a graphene nanoribbon supports localized zero modes, ignoring interactions. Based mainly on mean field arguments and numerical approaches, it has been suggested that interactions can produce a large magnetic moment on the edges. By considering the Hubbard model in the weak coupling limit, U<<t, for bearded as well as zigzag edges, we argue for such a magnetic state, based on Lieb's theorem. Projecting the Hubbard interactions onto the flat edge band, we then prove that resulting 1 dimensional model has a fully polarized ferromagnetic ground state. We also study excitons and the effects of second neighbor hopping as well as a potential energy term acting on the edge only, proposing a simple and possibly exact phase diagram with the magnetic moment varying smoothly to zero. Finally, we consider corrections of second order in U arising from integrating out the gapless bulk Dirac excitations.Comment: A rigorous proof of ferromagnetism is given in the small U limit, using a projected one dimensional Hamiltonia

Transverse spectral functions and Dzyaloshinskii-Moriya interactions in XXZ spin chains

Recently much progress has been made in applying field theory methods, first developed to study X-ray edge singularities, to interacting one dimensional systems in order to include band curvature effects and study edge singularities at arbitrary momentum. Finding experimental confirmations of this theory remains an open challenge. Here we point out that spin chains with uniform Dzyaloshinskii-Moriya (DM) interactions provide an opportunity to test these theories since these interactions may be exactly eliminated by a gauge transformation which shifts the momentum. However, this requires an extension of these X-ray edge methods to the transverse spectral function of the xxz spin chain in a magnetic field, which we provide

A Framework for Modelling Probabilistic Uncertainty in Rainfall Scenario Analysis

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Techniques of Eyebrow Lifting: A Narrative Review

None of brow lift techniques are completely satisfactory because of their limited effectiveness, lack of longevity, and potential complications. The aim of this study was to provide a comprehensive review of the literature on the pros and cons of the most popular techniques in brow and forehead lift. Relevant original articles in the PubMed database (English language) were sought using the search terms “eyebrow lift”, “forehead lift”, ”periorbital rejuvenation”, ”eyebrow ptosis”, ”blepharoplasty and eyebrow change”, ”surgical eyebrow lift”, and ”non-surgical eyebrow lift”, No date limitation was considered. Titles and abstracts were scanned to include the most pertinent articles. Subsequently, full texts of included articles (111 articles) were skimmed and finally 56 references were selected for the review. A narrative synthesis of data was finally undertaken with particular attention to the indications, techniques, and common complications of the eyebrow lift procedures. Ten popular techniques including two nonsurgical methods (Botulinum toxin A and soft tissue fillers) were reviewed in this article. In general, non-surgical methods of forehead/brow lift are temporary, need less experience and correction would be easier should any complication occur. Surgical methods are divided into three categories: trans-blepharoplasty eyebrow lift, direct eyebrow lift, and trans-forehead eyebrow/forehead lift. Currently, the most popular method is the endoscopic forehead lift approach even though its longevity is limited. Direct brow-lift is particularly useful in patients with facial palsy and those who are more likely to be accepting of the scar (male gender, high forehead hair line)

A case report of multiple organ involvement to hydatid cyst in a pregnant woman

Background and aims: Hydatid cyst disease is not considered as a common disease in humans, but because of the dangerous nature and its deployment in sensitive organs and problems related to treatment is seen as a major problem in many countries. Hydatid cyst disease with multiple organ involvement is rarely in Iran. Most cysts were mainly localized and do not symptoms more than involved organ. Some cases are random diagnosed by diagnostic Sonography during pregnancy or trauma. Case report: A 33-year-old pregnant woman with a history of a family trauma referred to Marand general hospital in 2015. Tomographic scan in her abdominal showed a large, well-defined heterogeneous mass. In ultrasonic examination, a multi-cystic mass with a large diameter of 84×64×86 mm with a volume of approximately 230 ml on the right side of the abdomen and immediately above right ovary was seen that it was an indicator of hydatid cyst. In upper right lobe of liver cystic mass with 32×39 mm diameters multilocular shape with multiple small cystic images were visible inside. The patient was candidate for open-abdomen surgery. Eight cystic mass was found in segments 3 and 4 and between the second and fourth segments and segment 7. Conclusion: Four cysts in liver and 2 cysts in pelvic, one cyst in the left ovary and one cyst in mesentery were observed. One of the cysts with severe adhesions underwent for cholecystectomy surgery. The patient was discharged from the hospital in good condition

Co-Optimization of Energy Losses and Transformer Operating Costs Based on Smart Charging Algorithm for Plug-in Electric Vehicle Parking Lots

The global transport sector has a significant share of greenhouse gas emissions. Thus, plug-in electric vehicles (PEVs) can play a vital role in the reduction of pollution. However, high penetration of PEVs can pose severe challenges to power systems, such as an increase in energy losses and a decrease in the transformers expected life. In this paper, a new day-ahead co-optimization algorithm is proposed to reduce the unwanted effects of PEVs on the power system. The aim of the proposed algorithm is minimizing the cost of energy losses as well as transformer operating cost by the management of active and reactive powers simultaneously. Moreover, the effect of harmonics, which are produced by the charger of PEVs, are considered in the proposed algorithm. Also, the transformer operating cost is obtained from a method that contains the purchase price, loading, and losses cost of the transformer. Another advantage of the proposed algorithm is that it can improve power quality parameters, e.g., voltage and power factor of the distribution network by managing the reactive power. Afterward, the proposed algorithm is applied to a real distribution network. The results show that the proposed algorithm optimizes the daily operating cost of the distribution network efficiently. Finally, the robustness of the proposed algorithm to the number and distribution of PEVs is verified by simulation results

European Medicine and Physicians in Safavid Iran

Simultaneous with the establishment of the Safavid dynasty, due to the developments in the global and regional relations, the ground was prepared for the expansion of Iran and Europe relations. The main reasons for this were the propagation of Christianity, the presence of the Ottoman government as a common enemy of Iran and Europe, as well as commercial interests. These relations reached their peak during the reign of Shah Abbas I., encouraging various groups of Europeans, such as religious missionaries, businessmen, ambassadors, political delegations, tourists, etc. to come to Iran.Physicians were seen in all the mentioned groups, especially in religious missionaries. So, owing to their presence, medical knowledge of European was introduced to Iranians. The first acquaintance with medical profession of European was obtained at the same time as the presence of the Portuguese in the Persian Gulf. Syphilis, which was first entered Iran from Europe in the late ninth century and was called smallpox, led European medicine to entering Iran.The researchers of the present study, based on the reports related to the presence and activity of European physicians in Iran, travelogues and historical and research books, have used a descriptive-analytical method to examine the medical status and European physicians in Safavid Iran

Choroidal Thickness in Acute Non-arteritic Anterior Ischemic Optic Neuropathy

Purpose: To compare the choroidal thickness in eyes with acute non-arteritic anterior ischemic optic neuropathy (NAION) with healthy contralateral eye and normal controls. Methods: Thirty-eight eyes with NAION, thirty-eight unaffected fellow eyes, and seventy four eyes from 37 healthy, age- and sex-matched subjects were included in this prospective comparative case-control study. Choroidal thickness was measured by enhanced depth imaging (EDI) of spectral domain optical coherence tomography (SDOCT). Peripapillary choroidal thickness (PCT) was measured at 1000 and 1500 μm from Bruch's membrane opening (BMO). Subfoveal choroidal thickness (SFCT) was measured in central subfoveal area, and 500 microns apart in temporal and nasal sides. Choroidal thickness among NAION eyes, uninvolved fellow eyes, and control eyes were compared. Results: The mean of PCT at 1000 μm was significantly thicker in NAION and fellow eyes compared to control eyes (169.7 ± 47, 154.4 ± 42.1, and 127.7 ± 49.9 μm, respectively, P &lt; 0.001 and P = 0.42). The mean PCT at 1500 μm was also significantly thicker in NAION and fellow eyes compared to control eyes (178.6 ± 52.8, 162.6 ± 46.1, and 135.1 ± 59 μm, respectively, P = 0.007 and P = 0.048). The mean PCT at 1000 and 1500 μm was significantly greater in NAION compared to fellow eyes (P = 0.027 and P = 0.035, respectively). The mean of SFCT was significantly thicker in NAION compared to control eyes (P = 0.032); however, there was no significant difference between uninvolved fellow and control eyes (P = 0.248). Conclusion: Thicker choroidal thickness in acute NAION and uninvolved fellow eyes compared to normal eyes suggests a primary choroidal role in NAION pathophysiology