Non-University Higher Education and the Relationship of Its Graduates and the World of Work: Colombia

The non-university sector has been part of the Colombian higher education system for more than 50-years. Despite its long years of existence, it has never occupied such an important role within the education system as the one it is having today. Therefore, the aim of this work is to analyze the development of the non-university sector in the framework of the country’s social, educational and economic demands. Likewise, its actual situation and certain aspects of the relationship between its graduates and the world of work, i.e., graduates’ employment characteristics, the relationship of higher education studies and their work, as well as their early career success, are examined. In order to generate the required information, a graduate survey was carried out in Atlántico (Colombia). The target population was graduates from higher education institutions registered in Atlántico who were awarded a technical, technological or professional degree in 2008 from any of the following knowledge areas: Fine Arts, Health Science, Economy-Administration-Accountancy and similar, and Engineering-Architecture-Urban planning and similar. Besides, interviews with academic and administrative staff from non-university institutions were carried out, and higher education related documents were analyzed. As a whole, the findings suggest that the non-university sector is expanding and may help to achieve some of the goals, for which it is widely promoted i.e., access expansion for under-represented groups, enhancement of the higher education system, and the provision of programs pertinent to the needs of the market. Nevertheless, some aspects require further consideration, e.g., the sector’s consolidation within the system and its quality. As for the relationship between non-university higher education and the world of work, it was found to be close; particularly in those aspects related to the use of knowledge and skills in the work, and the relationship between graduates’ studies and their work. Additionally, the analysis of the graduates’ in their early career stages exposes the significant role that the socioeconomic stratum plays in their working life, particularly in their wages. This indicates that apart from education, other factors like the graduates’ economic or social capital may have an impact on their future work perspectives

First-principles electronic theory of non-collinear magnetic order in transition-metal nanowires

The structural, electronic and magnetic properties of one-dimensional 3d transition-metal (TM) monoatomic chains having linear, zigzag and ladder geometries are investigated in the frame-work of first-principles density-functional theory. The stability of long-range magnetic order along the nanowires is determined by computing the corresponding frozen-magnon dispersion relations as a function of the 'spin-wave' vector q. First, we show that the ground-state magnetic orders of V, Mn and Fe linear chains at the equilibrium interatomic distances are non-collinear (NC) spin-density waves (SDWs) with characteristic equilibrium wave vectors q that depend on the composition and interatomic distance. The electronic and magnetic properties of these novel spin-spiral structures are discussed from a local perspective by analyzing the spin-polarized electronic densities of states, the local magnetic moments and the spin-density distributions for representative values q. Second, we investigate the stability of NC spin arrangements in Fe zigzag chains and ladders. We find that the non-collinear SDWs are remarkably stable in the biatomic chains (square ladder), whereas ferromagnetic order (q =0) dominates in zigzag chains (triangular ladders). The different magnetic structures are interpreted in terms of the corresponding effective exchange interactions J(ij) between the local magnetic moments μ(i) and μ(j) at atoms i and j. The effective couplings are derived by fitting a classical Heisenberg model to the ab initio magnon dispersion relations. In addition they are analyzed in the framework of general magnetic phase diagrams having arbitrary first, second, and third nearest-neighbor (NN) interactions J(ij). The effect of external electric fields (EFs) on the stability of NC magnetic order has been quantified for representative monoatomic free-standing and deposited chains. We find that an external EF, which is applied perpendicular to the chains, favors non-collinear order in V chains, whereas it stabilizes the ferromagnetic (FM) order in Fe chains. Moreover, our calculations reveal a change in the magnetic order of V chains deposited on the Cu(110) surface in the presence of external EFs. In this case the NC spiral order, which was unstable in the absence of EF, becomes the most favorable one when perpendicular fields of the order of 0.1 V/Å are applied. As a final application of the theory we study the magnetic interactions within monoatomic TM chains deposited on graphene sheets. One observes that even weak chain substrate hybridizations can modify the magnetic order. Mn and Fe chains show incommensurable NC spin configurations. Remarkably, V chains show a transition from a spiral magnetic order in the freestanding geometry to FM order when they are deposited on a graphene sheet. Some TM-terminated zigzag graphene-nanoribbons, for example V and Fe terminated nanoribbons, also show NC spin configurations. Finally, the magnetic anisotropy energies (MAEs) of TM chains on graphene are investigated. It is shown that Co and Fe chains exhibit significant MAEs and orbital magnetic moments with in-plane easy magnetization axis. The remarkable changes in the magnetic properties of chains on graphene are correlated to charge transfers from the TMs to NN carbon atoms. Goals and limitations of this study and the resulting perspectives of future investigations are discussed.