DIGITAL DISRUPTIONS: AN ANALYSIS OF TECHNOLOGICAL IMPACT ON STUDENT ENGAGEMENT IN THE CLASSROOM

Learning new skills and information can be one of the most time-consuming actions toengage in. Students can be considered the biggest contributor to this. It is very vital for schoolsto ensure that students are receiving the right tools to successfully motivate and further theirstudies. This study has been designed to measure the effects of technology that students are beingexposed to within K-12 level classrooms and whether it affects the student’s willingness toparticipate and ability to learn topics being taught in their respective grade level. The method ofresearch consisted of six interviews with teachers who are first-hand observing the effectstechnology exposure has had on their students and whether improvements or disadvantages arebeing experienced by these students. The teachers who were interviewed are from a variety ofschools within the Inland Empire of California to better understand the effects of technologyintegration across all content areas and analyze how educators are contributing to a student’sability to learn new curriculum. These interviews consist of personal experiences from teacherswhere successes and setbacks have been observed, analyzing different types of technology usedin their classrooms, and whether they feel they received sufficient training to guide their'scholars' to success. Readers of this study will be able to better comprehend the benefits and anyeffects take-home laptops, tablets, uses for online websites and further tech has had on thestudents of today

Group delay in THz spectroscopy with ultra-wideband log-spiral antennae

We report on the group delay observed in continuous-wave terahertz spectroscopy based on photomixing with phase-sensitive homodyne detection. We discuss the different contributions of the experimental setup to the phase difference \Delta\phi(\nu) between transmitter arm and receiver arm. A simple model based on three contributions yields a quantitative description of the overall behavior of \Delta\phi(\nu). Firstly, the optical path-length difference gives rise to a term linear in frequency. Secondly, the ultra-wideband log-spiral antennae effectively radiate and receive in a frequency-dependent active region, which in the most simple model is an annular area with a circumference equal to the wavelength. The corresponding term changes by roughly 6 pi between 100 GHz and 1 THz. The third contribution stems from the photomixer impedance. In contrast, the derivative (d\Delta\phi / d\nu) is dominated by the contribution of periodic modulations of \Delta\phi(\nu) caused by standing waves, e.g., in the photomixers' Si lenses. Furthermore, we discuss the Fourier-transformed spectra, which are equivalent to the waveform in a time-domain experiment. In the time domain, the group delay introduced by the log-spiral antennae gives rise to strongly chirped signals, in which low frequencies are delayed. Correcting for the contributions of antennae and photomixers yields sharp peaks or "pulses" and thus facilitates a time-domain-like analysis of our continuous-wave data.Comment: 7 pages, 7 figure

How much dark matter is there inside early-type galaxies?

We study the luminous mass as a function of the dynamical mass inside the effective radius (r_e) of early-type galaxies (ETGs) to search for differences between these masses. We assume Newtonian dynamics and that any difference between these masses is due to the presence of dark matter. We use several samples of ETGs -ranging from 19 000 to 98 000 objects- from the ninth data release of the Sloan Digital Sky Survey. We perform Monte Carlo (MC) simulations of galaxy samples and compare them with real samples. The main results are: i) MC simulations show that the distribution of the dynamical vs. luminous mass depends on the mass range where the ETGs are distributed (geometric effect). This dependence is caused by selection effects and intrinsic properties of the ETGs. ii) The amount of dark matter inside r_e is approximately 7% +- 22%. iii) This amount of dark matter is lower than the minimum estimate (10%) found in the literature and four times lower than the average (30%) of literature estimates. However, if we consider the associated error, our estimate is of the order of the literature average.Comment: 24 pages, 12 figures. MNRAS accepte