Uniaxial Tensile Properties of AS4 3D Woven Composites with Four Different Resin Systems: Experimental Results and Analysis: Property Computations

As a part of the NASA Composite Technology for Exploration project, eight different AS4 3D orthogonal woven composite panels were manufactured and were subjected to mechanical testing including uniaxial tension along the weaves' warp direction. Each set, with four different resin systems (KCR-IR6070, EP2400, RTM6, and RS-50), included weave architectures designed using 12K and 6K AS4 carbon fiber yarns. For the tension testing conducted at Room Temperature Ambient (RTA) conditions, the elastic modulus and strength of these eight panels (as-processed and thermally-cycled) were measured and compared while the potential evolution of micro-cracking before and after thermal cycling were monitored via optical microscopy and X-Ray Computed Tomography. The data set also included test results of the as-processed materials at Elevated Temperature Wet (ETW) conditions. In the second part of this study, efforts were made to compute elastic constants for AS4 6K/RTM6 and AS4 12K/RTM6 materials by implementing a finite element approach and the Multiscale Generalized Method of Cells (MSGMC) technique developed at NASA Glenn Research Center. Digimat-FE was used to model the weave architectures, assign properties, calculate yarn properties, create the finite element mesh, and compute the elastic properties by applying periodic boundary conditions to finite element models of each repeating unit cell. The required input data for MSGMC was generated using Matlab from Digimat exported weave information. Experimental and computational results were compared, and the differences and limitations in correlating to the test data were briefly discussed

RNAi‑mediated knockdown of E2F2 inhibits tumorigenicity of \ud human glioblastoma cells

In a previous genome‑wide expression profiling study, \ud we identified E2F2 as a hyperexpressed gene in stem‑like cells \ud of distinct glioblastoma multiforme (GBM) specimens. Since \ud the encoded E2F2 transcription factor has been implicated in \ud both tumor suppression and tumor development, we conducted a \ud functional study to investigate the pertinence of E2F2 to human \ud gliomagenesis. E2F2 expression was knocked down by trans‑\ud fecting U87MG cells with plasmids carrying a specific silencing \ud shRNA. Upon E2F2 silencing, in vitro cell proliferation was \ud significantly reduced, as indicated by a time‑course analysis of \ud viable tumor cells. Anchorage‑independent cell growth was also \ud significantly inhibited after E2F2 silencing, based on cell colony \ud formation in soft agar. Subcutaneous and orthotopic xenograft \ud models of GBM in nude mice also indicated inhibition of tumor \ud development in vivo, following E2F2 silencing. As expression \ud of the E2F2 gene is associated with glioblastoma stem cells \ud and is involved in the transformation of human astrocytes, the \ud present findings suggest that E2F2 is involved in gliomagenesis \ud and could be explored as a potential therapeutic target in malig‑\ud nant gliomas.This study was supported by grants from the National Institute of Science and Technology‑Stem Cells in Human Genetic Diseases, the National Council for Scientific and Technological Development (CNPq), the Coordination for the Improvement of Higher Education Personnel (CAPES), and the São Paulo Research Foundation (FAPESP). Dr Adriana M. Nakahata and Dr Daniela E. Suzuki were recipients of fellowships from CAPES and CNPq, respectively. Miss Carolina O. Rodini and Miss Mayara L. Fiuza received fellowships from FAPESP

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena.Comment: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figure