Quantum transport in disordered and strain-engineered graphene

The first part of the present thesis investigates the electronic transport in strain-engineered graphene, which has been proposed as a way to circumvent the problem of an absent bandgap in this material. To that end, we calculate the conductivity, the shot noise and the density of states in the Dirac-Kronig-Penney model, which describes the phase-coherent transport in clean monolayer samples with a one-dimensional periodic modulation of the strain and the electrostatic potential. We find that periodic strains induce large pseudo-gaps and suppress charge transport in the direction of the strain modulation while the effect for periodic electrostatic potentials is weakened by Klein tunnelling. The second part then deals with the transport properties of graphene at charge neutrality when disordered by adatoms or scalar impurities. A scattering theory for the Dirac equation yields an analytic expression for the conductivity given a particular impurity configuration; an averaging over impurity configurations is performed numerically. For strong magnetic fields, the conductivity equals the ballistic value, while for weaker fields, a rich scaling flow is obtained which is governed by fixed points of different symmetry classes. In the absence of a magnetic field, a surprising rise of the conductivity is observed when increasing the density of adatoms that are randomly arranged on sites of the same Bloch-phase

A new ecosystem services approach to enable identification of pro-biodiversity businesses of protected karst areas in Central and South-Eastern Europe

This study was completed in the frame of the project ECO KARST – Ecosystem services of karst protected areas – driving force of local sustainable development, funded by Interreg Danube Transnational Programme.Protected areas are a leading conservation tool for preserving biodiversity. However, the restrictions on human uses often engender resistance of local communities to the idea of living in protected environment. This paper describes the preparation of Biodiversity Investment Opportunities (BIO) maps for seven case areas in Central and South-Eastern Europe, using participatory methods. BIO maps have been further developed with the in-volvement of local stakeholders to define areas that can support economic activities while achieving a no net loss or even benefits for nature. The BIO maps can then be used to foster the development of Pro-Biodiversity Businesses (PBBs). PBBs are enterprises that generate financial returns without compromising the natural envi-ronments they depend on. PBBs were found to be a viable solution, effective in changing the perceptions of both the park managers and the local people towards the protected areas. Moreover, these enterprises can improve the local livelihoods, as well as actively protect nature and biodiversity. Therefore, the approach presented in this paper can be adopted as a model for managing any protected area and conserving cultural landscapes.Publisher PDFPeer reviewe

Moire superlattice effects in graphene/boron-nitride van der Waals heterostructures

Van der Waals heterostructures of graphene and hexagonal boron nitride feature a moir\'e superlattice for graphene's Dirac electrons. Here, we review the effects generated by this superlattice, including a specific miniband structure featuring gaps and secondary Dirac points, and a fractal spectrum of magnetic minibands known as Hofstadter's butterfly.Comment: 25 pages, 7 figure

Rhabdomyoblastic Differentiation in Head and Neck Malignancies Other Than Rhabdomyosarcoma

Rhabdomyosarcoma is a relatively common soft tissue sarcoma that frequently affects children and adolescents and may involve the head and neck. Rhabdomyosarcoma is defined by skeletal muscle differentiation which can be suggested by routine histology and confirmed by immunohistochemistry for the skeletal muscle-specific markers myogenin or myoD1. At the same time, it must be remembered that when it comes to head and neck malignancies, skeletal muscle differentiation is not limited to rhabdomyosarcoma. A lack of awareness of this phenomenon could lead to misdiagnosis and, subsequently, inappropriate therapeutic interventions. This review focuses on malignant neoplasms of the head and neck other than rhabdomyosarcoma that may exhibit rhabdomyoblastic differentiation, with an emphasis on strategies to resolve the diagnostic dilemmas these tumors may present. Axiomatically, no primary central nervous system tumors will be discussed.info:eu-repo/semantics/publishedVersio