First principles design of divacancy defected graphene nanoribbon based rectifying and negative differential resistance device

We have elaborately studied the electronic structure of 555-777 divacancy (DV) defected armchair edged graphene nanoribbon (AGNR) and transport properties of AGNR based two-terminal device constructed with one defected electrode and one N doped electrode, by using density functional theory and non-equilibrium Green's function based approach. The introduction of 555-777 DV defect into AGNRs, results in a shifting of the {\pi} and {\pi}* bands towards the higher energy value which indicates a shifting of the Fermi level towards the lower energy. Formation of a potential barrier, very similar to that of conventional p-n junction, has been observed across the junction of defected and N doped AGNR. The prominent asymmetric feature of the current in the positive and negative bias indicates the diode like property of the device with high rectifying efficiency within wide range of bias voltages. The device also shows robust negative differential resistance (NDR) with very high peak-to-valley ratio. The analysis of the shifting of the energy states of the electrodes and the modification of the transmission function with applied bias provides an insight into the nonlinearity and asymmetry observed in the I-V characteristics. Variation of the transport properties on the width of the ribbon has also been discussed.Comment: 28 Pages, 12 Figures and 1 tabl

Endovascular treatment of intracranial aneurysms using balloon remodeling technique

Endovascular treatment with coils is widely used in the management of intracranial aneurysms. However, this type of treatment can be technically challenging for anatomic reasons, particularly when the neck of the aneurysm is wide or when the dome-to-neck ratio is not favorable. Previous studies described the remodeling technique for extending the indications and feasibility of the endovascular treatment to wide-neck intracranial aneurysms. In remodeling technique, a non-detachable balloon is temporarily inflated in front of the neck of the aneurysm during each coil placement. At the end of the procedure, the remodeling balloon is removed and no device is left in place in the parent vessel unless stent placement is subsequently performed. The remodeling technique can be used in all aneurysm locations but is adopted less frequently in anterior communicating and anterior cerebral aneurysms. Studies have also shown adequate aneurysm occlusion is significantly more frequent in the remodeling group. Despite the fact that aneurysms treated by the remodeling technique are different from aneurysms treated with standard coiling, the safety of both techniques is similar with a higher anatomic efficacy of the remodeling technique. Accordingly, wide use of the remodeling technique can be proposed

Varied percutaneous and endovascular management of large iatrogenic profunda femoris artery pseudoaneurysm

The case of an elderly male diagnosed with a large iatrogenic pseudoaneurysm arising from the profunda femoris artery on ultrasound examination is presented. The immediate postoperative period was uneventful; however later he developed leg swelling and mild oozing at the incision site. In view of deranged renal function CT angiogram was not done and decision was made to treat the pseudoaneurysm with percutaneous thrombin injection. Almost complete thrombosis was achieved however a small residual portion remained patent near the neck. Later limited contrast angiography was done which re-demonstrated a small anneurysm. Instead of embolizing the vessel completely repeat prolonged balloon inflation was done which later showed no further filling of the pseudoaneurysm

Being in Communion : a qualitative study of young lay women's experiences of the Eucharist

This thesis explores young lay women’s experiences of Communion in the Church of England within a framework of practical feminist theology. After grounding the study in a review of relevant feminist literature on the Eucharist, the use of qualitative research methodology is described. Semi-structured interviews with ten young women revealed three central themes: ways in which women experience and respond to exclusion and alienation from Communion; the importance of relationality and community; and how experience leads women to construct their own understandings about Communion. Ambiguity and difference within women’s experience are key concepts. Some embrace traditional understandings and practices of Communion; others subvert these to claim new and liberating understandings for themselves and their communities. The thesis points to a desire to deconstruct boundaries, creating a vision of inclusive and egalitarian Eucharistic community where loci of power and authority are challenged by the quest for personal autonomy and relationship in community. The research process is shaped by the pastoral cycle method of theological reflection. This leads to the suggestion of a metaphor of birthing as a means of responding to the experiences and needs revealed by the research and a model for developing liberational Eucharistic theology forEThOS - Electronic Theses Online ServiceGBUnited Kingdo

Light outcoupling efficiency of top-emitting organic light-emitting diodes

Copyright © 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 84 (2004) and may be found at http://link.aip.org/link/?APPLAB/84/2986/1We report results obtained from modeling the light outcoupling efficiency of top–emitting organic light-emitting diode (OLED) structures and compare them with results from conventional substrate-emitting structures. We investigate two types of emissive material, small molecule and conjugated polymers, and study three different cathode materials; aluminum, silver, and calcium. We show that top-emitting OLEDs may have outcoupling efficiencies comparable to their substrate-emitting counterparts, and that the choice of cathode material is critical to the optical performance of the device

Coupled surface plasmon-polariton mediated photoluminescence from a top-emitting organic light-emitting structure

Copyright © 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 85 (2004) and may be found at http://link.aip.org/link/?APPLAB/85/182/1We report strong photoluminescence from a top-emitting organic light-emitting structure where emission takes place through a thin (55 nm) silver film. We show that this emission is mediated via coupled surface plasmon-polariton modes. Our results show that the addition of a dielectric grating to otherwise planar structures, such as surface-emitting organic light-emitting diodes, may offer a way to increase the external efficiency of top-emitting organic light-emitting diodes

Hirayama disease, a rare cause of posture related cord compression: a case report from radiological perspective

Hirayama Disease is a disease of young adults lying in the age group between twenty to thirty years. It is an extremely uncommon disorder. Its other synonyms are juvenile muscular atrophy of the distal upper extremity (JMADUE) or monomelic amyotrophy (MMA). A previously healthy 25-year-old man presented with gradually increasing weakness in both hands for the past few years. There was neither history of trauma nor family history of neuromuscular disease. MRI was advised. Routine cervical sagittal MR images (Non-flexion or extension) revealed cord flattening and atrophy at C5 to C7 levels.There was evidence of syrinx. Flexion MRI was performed later on. Midline sagittal T1- and T2-weighted images of the cervical spine showed anterior displacement of the cervical cord with marked flattening of cord. The patient was advised to modify his posture, avoid flexion and to apply cervical collar. Physiotherapy was started to improve the tone of muscles. In case of deterioration of symptoms he was advised to consult for surgery. The purpose of this case report is to show the importance of dynamic scan in symptomatic patients especially in their second or third decade with progressive upper limb weakness. Mostly the scanning in neutral posture does not reveal any significant cord compression. Similarly a normal looking thecal sac with preserved anterior and posterior thecal sleeves without disc disease dramatically changes on change of posture. This case shows the importance of dynamic scanning in symptomatic patients with progressive upper limb weakness and with no obvious cause of the cord changes on routine MR images. Cervical collar, physiotherapy and in resistant cases surgery is recommended for management