11 research outputs found
Search for a Light Higgs Boson and Low Mass Dark Matter at the Belle Experiment.
Ph.D. Thesis. University of HawaiÊ»i at MÄnoa 2017
Fabrication of Coaxial Si1âxGex Heterostructure Nanowires by O2 Flow-Induced Bifurcate Reactions
We report on bifurcate reactions on the surface of well-aligned Si1âxGex nanowires that enable fabrication of two different coaxial heterostructure nanowires. The Si1âxGex nanowires were grown in a chemical vapor transport process using SiCl4 gas and Ge powder as a source. After the growth of nanowires, SiCl4 flow was terminated while O2 gas flow was introduced under vacuum. On the surface of nanowires was deposited Ge by the vapor from the Ge powder or oxidized into SiO2 by the O2 gas. The transition from deposition to oxidation occurred abruptly at 2 torr of O2 pressure without any intermediate region and enables selectively fabricated Ge/Si1âxGex or SiO2/Si1âxGex coaxial heterostructure nanowires. The rate of deposition and oxidation was dominated by interfacial reaction and diffusion of oxygen through the oxide layer, respectively
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in
Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
Enhanced Neurite Outgrowth by Intracellular Stimulation
Electrical stimulation through direct
electrical activation has
been widely used to recover the function of neurons, primarily through
the extracellular application of thin film electrodes. However, studies
using extracellular methods show limited ability to reveal correlations
between the cells and the electrical stimulation due to interference
from external sources such as membrane capacitance and culture medium.
Here, we demonstrate long-term intracellular electrical stimulation
of undamaged pheochromocytoma (PC-12) cells by utilizing a vertical
nanowire electrode array (VNEA). The VNEA was prepared by synthesizing
silicon nanowires on a Si substrate through a vaporâliquidâsolid
(VLS) mechanism and then fabricating them into electrodes with semiconductor
nanodevice processing. PC-12 cells were cultured on the VNEA for 4
days with intracellular electrical stimulation and then a 2-day stabilization
period. Periodic scanning via two-photon microscopy confirmed that
the electrodes pierced the cells without inducing damage. Electrical
stimulation through the VNEA enhances cellular differentiation and
neurite outgrowth by about 50% relative to extracellular stimulation
under the same conditions. VNEA-mediated stimulation also revealed
that cellular differentiation and growth in the cultures were dependent
on the potential used to stimulate them. Intracellular stimulation
using nanowires could pave the way for controlled cellular differentiation
and outgrowth studies in living cells
Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume I Introduction to DUNE
International audienceThe preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decayâthese mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE's physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology
Deep Underground Neutrino Experiment (DUNE), Far Detector Technical Design Report, Volume II: DUNE Physics
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay -- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. DUNE is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume II of this TDR, DUNE Physics, describes the array of identified scientific opportunities and key goals. Crucially, we also report our best current understanding of the capability of DUNE to realize these goals, along with the detailed arguments and investigations on which this understanding is based. This TDR volume documents the scientific basis underlying the conception and design of the LBNF/DUNE experimental configurations. As a result, the description of DUNE's experimental capabilities constitutes the bulk of the document. Key linkages between requirements for successful execution of the physics program and primary specifications of the experimental configurations are drawn and summarized. This document also serves a wider purpose as a statement on the scientific potential of DUNE as a central component within a global program of frontier theoretical and experimental particle physics research. Thus, the presentation also aims to serve as a resource for the particle physics community at large