934 research outputs found

    Social Media Marketing

    Get PDF
    Hespr is a mental health startup that believes that mental health is both a personal journey as well as a community one. Hespr is building an application that incorporates this idea using a guided journal, which facilitates the personal journey and a social platform to foster the community journey. It has a strong back-end which uses a variety of algorithms to calculate the emotions of the user. It combines all this with a sleek and functional UI. They focus on creating positive change in the world along with reimagining the way mental health is perceived and treated. As a marketing intern I would help promote the app on social media and create a marketing strategy to accomplish this. This strategy would include content creation, research, competitor analysis, and customer outreach. Throughout this process, multiple revisions to content would be made, and the company leadership would be debriefed to future plans. I submitted work to the CMO of the company, Ayaan Dhir, and for larger projects would talk to the CEO, Ethan Talreja, directly. I worked alongside 3 other interns: Eunice Kim, Edward Zhang, and Kaylee Zhou. Throughout this internship, my professional skills developed greatly. I gained graphic design, networking, and communication skills.https://digitalcommons.imsa.edu/intern_reports_2020/1000/thumbnail.jp

    Modern treatment methods of primary childhood dental caries

    Get PDF
    The uniqueness of tooth enamel focal demineralization (primary caries) is that it is the only form of tooth decay, which can be treated conservatively without any surgical treatment and filling. Therefore, the integral task in dentistry is to study all the possibilities of diagnosis and to increase the effectiveness of conservative treatment. To determine the dental health of children in Omsk we carried out a dental check-up of 1682 schoolchildren from 7 to 12 years of ag

    Size-dependent bandgap and particle size distribution of colloidal semiconductor nanocrystals

    Get PDF
    A new analytical expression for the size-dependent bandgap of colloidal semiconductor nanocrystals is proposed within the framework of the finite-depth square-well effective mass approximation in order to provide a quantitative description of the quantum confinement effect. This allows one to convert optical spectroscopic data (photoluminescence spectrum and absorbance edge) into accurate estimates for the particle size distributions of colloidal systems even if the traditional effective mass model is expected to fail, which occurs typically for very small particles belonging to the so-called strong confinement limit. By applying the reported theoretical methodologies to CdTe nanocrystals synthesized through wet chemical routes, size distributions are inferred and compared directly to those obtained from atomic force microscopy and transmission electron microscopy. This analysis can be used as a complementary tool for the characterization of nanocrystal samples of many other systems such as the II-VI and III-V semiconductor materials.Comment: 9 pages, 5 figure

    Superconductivity in silicon nanostructures

    Full text link
    We present the findings of the superconductivity observed in the silicon nanostructures prepared by short time diffusion of boron on the n-type Si(100) surface. These Si-based nanostructures represent the p-type ultra-narrow self-assembled silicon quantum wells, 2nm, confined by the delta - barriers heavily doped with boron, 3nm. The EPR and the thermo-emf studies show that the delta - barriers appear to consist of the trigonal dipole centres, which are caused by the negative-U reconstruction of the shallow boron acceptors. Using the CV and thermo-emf techniques, the transport of two-dimensional holes inside SQW is demonstrated to be accompanied by single-hole tunneling through these negative-U centres that results in the superconductivity of the delta - barriers. The values of the correlation gaps obtained from these measurements are in a good agreement with the data derived from the temperature and magnetic field dependencies of the magnetic susceptibility, which reveal a strong diamagnetism and additionally identify the superconductor gap value.Comment: 4 pages, 6 figures, presented at the 4th International Conference on Vortex Matter in Superconductors, Crete, Greece, September 3-9, 200

    Optically tunable nuclear magnetic resonance in a single quantum dot

    No full text
    We report optically detected nuclear magnetic resonance (ODNMR) measurements on small ensembles of nuclear spins in single GaAs quantum dots. Using ODNMR we make direct measurements of the inhomogeneous Knight field from a photoexcited electron which acts on the nuclei in the dot. The resulting shifts of the NMR peak can be optically controlled by varying the electron occupancy and its spin orientation, and lead to strongly asymmetric line shapes at high optical excitation. The all-optical control of the NMR line shape will enable position-selective control of small groups of nuclear spins inside a dot

    Superconducting and Normal State Properties of Heavily Hole-Doped Diamond

    Full text link
    We report measurements of the specific heat, Hall effect, upper critical field and resistivity on bulk, B-doped diamond prepared by reacting amorphous B and graphite under high-pressure/high-temperature conditions. These experiments establish unambiguous evidence for bulk superconductivity and provide a consistent set of materials parameters that favor a conventional, weak coupling electron-phonon interpretation of the superconducting mechanism at high hole doping.Comment: 10 pages, 3 figure

    Biexciton recombination rates in self-assembled quantum dots

    Get PDF
    The radiative recombination rates of interacting electron-hole pairs in a quantum dot are strongly affected by quantum correlations among electrons and holes in the dot. Recent measurements of the biexciton recombination rate in single self-assembled quantum dots have found values spanning from two times the single exciton recombination rate to values well below the exciton decay rate. In this paper, a Feynman path-integral formulation is developed to calculate recombination rates including thermal and many-body effects. Using real-space Monte Carlo integration, the path-integral expressions for realistic three-dimensional models of InGaAs/GaAs, CdSe/ZnSe, and InP/InGaP dots are evaluated, including anisotropic effective masses. Depending on size, radiative rates of typical dots lie in the regime between strong and intermediate confinement. The results compare favorably to recent experiments and calculations on related dot systems. Configuration interaction calculations using uncorrelated basis sets are found to be severely limited in calculating decay rates.Comment: 11 pages, 4 figure
    corecore