The Societal Implications of Astrobiological Life

With the launch of the Perseverance Rover to Mars in search of signs of life, many questions arise in regards to the societal implications of finding astrobiological life. Many of these questions include what the life will look like and how will the general public react to this life. The implications regarding this life include ethical decisions that must be made such as how scientists should approach studying this life or if they are even ethically allowed to examine it. Lastly, if life is found, we must decide if scientists are responsible in aiding life on mars. Overall, the discovery of astrobiological life will expand and reshape the field of science and open many new goals related to space exploration

Solubility of precursors and carbonation of waterglass-free geopolymers

Geopolymers have the potential to function as an environmentally friendly substitute for ordinary Portland cement, with up to 80% less CO$_{2}$ emission during production. The effect is best utilized for geopolymers prepared with amorphous silica instead of waterglass (Na$_{2x}$Si$_{y}$O$_{2y+x}$) to adjust the Si:Al ratio. The reactivity of the precursors with the alkaline activator affects the final mineralogical properties of the binder. The purpose of the present study was to investigate the amount of different phases formed during geopolymerization and to understand the quantitative evolution of carbonation during geopolymer synthesis by determining the solubility of metakaolinite and amorphous SiO$_{2}$ in NaOH at various concentrations. The solubility was studied by ICP-OES measurements. X-ray diffraction was used for qualitative and quantitative phase analysis of the geopolymers. The solubility of the precursors increased with calcination temperature of metakaolinite, reaction time for amorphous SiO$_{2}$, and at higher NaOH concentrations. Partial dissolution resulted in free Na$^{+}$, which is a source for the formation of carbonates in the geopolymers. Thermonatrite occurred prior to trona formation in all samples

Exploring the Impact of the Habitat for Humanity Home-Building Process on Partner Families\u27 Holistic Well-Being

The purpose of this study was to evaluate how participating in the Habitat for Humanity house-building process influenced participants’ purpose well-being, social well-being, community well-being, physical and mental well-being, and financial well-being, and how effective Habitat for Humanity is in aiding neighborhood revitalization within the Greater Lafayette area. The research project resulted in a presentation of quantitative data and a testimonial video that highlighted the stories of families that had worked with Habitat for Humanity. Quantitative data was gathered through a survey that addressed respondents’ levels of satisfaction within the various categories of well-being mentioned above. Testimonial information was gathered from interviews with respondents to gain a more personal insight into their stories. The majority of respondents indicated their satisfaction with the overall Habitat for Humanity process and noticeable positive impacts on all aspects of their well-being. Responses were more varied to questions regarding a sense of community within their neighborhoods and a sense of safety. Respondents also indicated occasional dissatisfaction with the inadequate level of homeowner-related education provided through the Habitat for Humanity house-building process. Habitat for Humanity might consider focusing more attention on neighborhood revitalization initiatives including a focus on a general sense of community, overall safety, and periodic check-ins with those who have previously participated in the house-building project

Various Improvements to Operate the 1.5GeV HDSM at MAMI

During the last three years at the 1.5GeV Harmonic Double Sided Microtron HDSM, [1] of MAMI a lot of improvements concerning the longitudinal operation of the accelerator were tested and installed. To monitor the rf power dissipated in the accelerating sections, their cooling water flow and its temperature rise are now continuously logged. Phase calibration measurements of the linacs and the phase intensity monitors p i monitors revealed nonlinearities of the high precision step motor driven waveguide phase shifters. They were recalibrated to deliver precise absolute values. Thereby it is now possible to measure not only the first turn s phase very exactly, but also to determine the linac s rf amplitude within an error of less than 5 using the well known longitudinal dispersion of the bending system. These results are compared to the thermal load measurements. For parity violation experiments the beam energy has to be stabilised to some 10 amp; 8722;6. A dedicated system measuring the time of flight through a bending magnet is now used in routine operation and controls the output energy via the linac phase

When is a symmetric pin-jointed framework isostatic?

Maxwell's rule from 1864 gives a necessary condition for a framework to be isostatic in 2D or in 3D. Given a framework with point group symmetry, group representation theory is exploited to provide further necessary conditions. This paper shows how, for an isostatic framework, these conditions imply very simply stated restrictions on the numbers of those structural components that are unshifted by the symmetry operations of the framework. In particular, it turns out that an isostatic framework in 2D can belong to one of only six point groups. Some conjectures and initial results are presented that would give sufficient conditions (in both 2D and 3D) for a framework that is realized generically for a given symmetry group to be an isostatic framework.Comment: 24 pages, 10 figures; added references, minor changes, revised last paragrap

Loop operators and S-duality from curves on Riemann surfaces

We study Wilson-'t Hooft loop operators in a class of N=2 superconformal field theories recently introduced by Gaiotto. In the case that the gauge group is a product of SU(2) groups, we classify all possible loop operators in terms of their electric and magnetic charges subject to the Dirac quantization condition. We then show that this precisely matches Dehn's classification of homotopy classes of non-self-intersecting curves on an associated Riemann surface--the same surface which characterizes the gauge theory. Our analysis provides an explicit prediction for the action of S-duality on loop operators in these theories which we check against the known duality transformation in several examples.Comment: 41 page

Ionic and electronic properties of the topological insulator Bi2_2Te2_2Se investigated using β\beta-detected nuclear magnetic relaxation and resonance of 8^8Li

We report measurements on the high temperature ionic and low temperature electronic properties of the 3D topological insulator Bi$_2$Te$_2$Se using ion-implanted $^8$Li $\beta$-detected nuclear magnetic relaxation and resonance. With implantation energies in the range 5-28 keV, the probes penetrate beyond the expected range of the topological surface state, but are still within 250 nm of the surface. At temperatures above ~150 K, spin-lattice relaxation measurements reveal isolated $^8$Li$^{+}$ diffusion with an activation energy $E_{A} = 0.185(8)$ eV and attempt frequency $\tau_{0}^{-1} = 8(3) \times 10^{11}$ s$^{-1}$ for atomic site-to-site hopping. At lower temperature, we find a linear Korringa-like relaxation mechanism with a field dependent slope and intercept, which is accompanied by an anomalous field dependence to the resonance shift. We suggest that these may be related to a strong contribution from orbital currents or the magnetic freezeout of charge carriers in this heavily compensated semiconductor, but that conventional theories are unable to account for the extent of the field dependence. Conventional NMR of the stable host nuclei may help elucidate their origin.Comment: 17 pages, 12 figures, submitted to Phys. Rev.

Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering off 28^{28}Si and 90^{90}Zr

We report on a new measurement of the beam-normal single spin asymmetry $A_{\mathrm{n}}$ in the elastic scattering of 570 MeV transversely polarized electrons off $^{28}$Si and $^{90}$Zr at $Q^{2}=0.04\, \mathrm{GeV}^2/c^2$. The studied kinematics allow for a comprehensive comparison with former results on $^{12}$C. No significant mass dependence of the beam-normal single spin asymmetry is observed in the mass regime from $^{12}$C to $^{90}$Zr.Comment: Submitted for publication to Physics Letters