MIRA Modular Interchangeable Robotic Arm

Low-cost robotic arms are becoming much more popular in educational settings. The goal of this project is to create a proof of concept for a modular robotic arm. To accomplish this, we have modified an existing arm to use our own modular control system, created a removable joint that can be connected to the end of the arm, and created an end-user interface which allows visualization of the arm’s movement in real time. Creating this arm will make robotics education accessible to a larger number of people, without compromising the potential for each person to gain a high quality understanding of the way robotic arms behave

On the Origin of the Highest Redshift Gamma-Ray Bursts

GRB 080913 and GRB 090423 are the most distant gamma-ray bursts (GRBs) known to date, with spectroscop-ically determined redshifts of z = 6.7 and z = 8.1, respectively. The detection of bursts at this early epoch of the universe significantly constrains the nature of GRBs and their progenitors. We perform population synthesis studies of the formation and evolution of early stars, and calculate the resulting formation rates of short- and long-duration GRBs at high redshift. The peak of the GRB rate from Population II stars occurs at z ∼ 7for a model with efficient/fast mixing of metals, while it is found at z ∼ 3 for an inefficient/slow metallicity evolu-tion model. We show that in the redshift range 6 \u3c z \u3c 10, essentially all GRBs originate from Population II stars, regardless of the metallicity evolution model. These stars (having small, but non-zero metallicity) are the most likely progenitors for both long GRBs (collapsars) and short GRBs (neutron star–neutron star or blackhole–neutron star mergers) at this epoch. Although the predicted intrinsic rates of long and short GRBs are similar at these high red-shifts, observational selection effects lead to higher (a factor of ∼10) observed rates for long GRBs. We conclude that the two recently observed high-z GRB events are most likely long GRBs originating from Population II collapsars