Positron scattering and annihilation from the hydrogen molecule at zero energy

The confined variational method is used to generate a basis of correlated gaussians to describe the interaction region wave function for positron scattering from the H$_2$ molecule. The scattering length was $\approx -2.7$ $a_0$ while the zero energy $Z_{\rm eff}$ of 15.7 is compatible with experimental values. The variation of the scattering length and $Z_{\rm eff}$ with inter-nuclear distance was surprisingly rapid due to virtual state formation at $R \approx 3.4$ $a_0$

Systematic {\it ab initio} study of the magnetic and electronic properties of all 3d transition metal linear and zigzag nanowires

It is found that all the zigzag chains except the nonmagnetic (NM) Ni and antiferromagnetic (AF) Fe chains which form a twisted two-legger ladder, look like a corner-sharing triangle ribbon, and have a lower total energy than the corresponding linear chains. All the 3d transition metals in both linear and zigzag structures have a stable or metastable ferromagnetic (FM) state. The electronic spin-polarization at the Fermi level in the FM Sc, V, Mn, Fe, Co and Ni linear chains is close to 90% or above. In the zigzag structure, the AF state is more stable than the FM state only in the Cr chain. It is found that the shape anisotropy energy may be comparable to the electronic one and always prefers the axial magnetization in both the linear and zigzag structures. In the zigzag chains, there is also a pronounced shape anisotropy in the plane perpendicular to the chain axis. Remarkably, the axial magnetic anisotropy in the FM Ni linear chain is gigantic, being ~12 meV/atom. Interestingly, there is a spin-reorientation transition in the FM Fe and Co linear chains when the chains are compressed or elongated. Large orbital magnetic moment is found in the FM Fe, Co and Ni linear chains

History, Research, and Theory to Practice: Scaffolding Framework for Graduate Online Courses

The expansion of modern technology has vastly changed and continues to change the way we learn, communicate, and connect with one another. Institutions of higher learning including Community Colleges and Universities, traditionally known for their face-to-face courses, have had to reconsider programmatic and delivery mode over the years to transfer their face-to-face courses into online courses based on the growing demand. With this transition, comes reflective reevaluation of curriculum and programmatic structure of courses. These programmatic courses must provide instructional experiences that are meaningful and purposeful for graduate students in higher education and prepare them in the same manner and level of quality as face-to-face courses. There is a need for pedagogical research to assist faculty and instructors to make this transition to online teaching. The following paper examines 1) the historical context of distance education 2) research on face-to-face instruction in comparison to online instruction 3) a modern framework for scaffolding graduate courses and graduate course content