Search results for "scatter"

Micelles in Mixtures of Sodium Dodecyl Sulfate and a Bolaform Surfactant

2006

Mixtures composed of water, sodium dodecyl sulfate (SDS), and a bolaform surfactant with two aza-crown ethers as polar headgroups (termed Bola C-16) were investigated by modulating the mole ratios between the components. The two surfactants have ionic and nonionic, but ionizable, headgroups, respectively. The ionization is due to the complexation of alkali ions by the aza-crown ether unit(s). Structural, thermodynamic, and transport properties of the above mixtures were investigated. Results from surface tension, translational self-diffusion, and small angle neutron scattering ( SANS) are reported and discussed. Interactions between the two surfactants to form mixed micelles result in a com…

Improved measurement of $^8$B solar neutrinos with $1.5  kt·y$ of Borexino exposure

2017

We report on an improved measurement of the $^8$B solar neutrino interaction rate with the Borexino experiment at the Laboratori Nazionali del Gran Sasso. Neutrinos are detected via their elastic scattering on electrons in a large volume of liquid scintillator. The measured rate of scattered electrons above 3 MeV of energy is $0.223\substack{+0.015 \\ -0.016}\,(stat)\,\substack{+0.006 \\ -0.006}\,(syst)$ cpd/100 t, which corresponds to an observed solar neutrino flux assuming no neutrino flavor conversion of $\Phi\substack{\rm ES \\ ^8\rm B}=2.57\substack{+0.17 \\ -0.18}(stat)\substack{+0.07\\ -0.07}(syst)\times$10$^6$ cm$^{-2}\,$s$^{-1}$. This measurement exploits the active volume of the …

Nanocomposites based on block copolymers and inorganic nanoparticles. Structural and thermal properties

2009

Preparation of Nd:YAG Nanopowder in a Confined Environment

2007

Nanopowder of yttrium aluminum garnet (YAG, Y3Al5O12) doped with neodymium ions (Nd:YAG) was prepared in the water/cetyltrimethylammonium bromide/1-butanol/n-heptane system. Aluminum, yttrium, and neodymium nitrates were used as starting materials, and ammonia was used as a precipitating agent. Coprecipitate hydroxide precursors where thermally treated at 900 degrees C to achieve the garnet phase. The starting system with and without reactants was characterized by means of the small-angle neutron scattering technique. The system, without reactants, is constituted by a bicontinuous structure laying near the borderline with the lamellar phase region. The introduction of nitrates stabilizes th…

Characterisation of single semiconductor nanowires by non-destructive spectroscopies

2015

Los nanohilos semiconductores (NWs, de su nombre inglés, nanowires) tienen una amplia gama de aplicaciones en el campo de la optoelectrónica (emisores de luz y diodos láser), nano-electrónica (circuitos lógicos y transistores de efecto de campo), y detección y producción de energía (células solares). En términos generales, los NWs pueden ser descritos como nanoestructuras de forma alargada con diámetros que van típicamente de decenas a cientos de nanómetros, y con longitudes que oscilan desde pocas hasta las decenas de micras. Dicha morfología ofrece dos ventajas principales en comparación con las capas: su alta relación superficie-volumen y su mayor calidad cristalina, ambas beneficiosas p…

Neutrino-nucleus scattering off 136Xe

2015

Background: Theoretical estimates of the cross sections for the neutrino-nucleus scattering off relevant nuclei for supernova neutrinos are essential for many applications in neutrino physics and astrophysics. The double- β-decaying nucleus 136Xe nucleus is used by the EXO Collaboration in the search for neutrinoless double-β decay. A ton-scale experiment based on 136Xe could also be used for studies of supernova neutrinos and/or solar neutrinos. Purpose: The purpose of the present work is, thus, to perform a study of the charged-current and neutral-current nuclear responses to supernova neutrinos for 136Xe. Method: The cross sections are computed by using the well-established framework for…

Nuclear structure and neutrino-nucleus reactions at supernova energies

2015

Supernova-(anti-)neutrino–nucleus scattering is discussed with reference to neutral-current (NC) and charged-current (CC) processes in heavy stable nuclei. The Donnelly-Walecka method with the associated multipole expansion of the nucleonic current has been adopted as the basic framework in deriving the neutrino-nucleus scattering cross sections. The needed nuclear wave functions are computed by using the quasiparticle random-phase approximation (QRPA) for the even-even target nuclei in the NC processes and the proton-neutron QRPA (pnQRPA) has been used to compute the CC processes for the mentioned nuclei. The wave functions of the stable odd-mass target nuclei have been obtained by the use…

Snowmass Neutrino Frontier: Neutrino Interaction Cross Sections (NF06) Topical Group Report

2022

A thorough understanding of neutrino cross sections in a wide range of energies is crucial for the successful execution of the entire neutrino physics program. In order to extract neutrino properties, long-baseline experiments need an accurate determination of neutrino cross sections within their detector(s). Since very few of the needed neutrino cross sections across the energy spectrum are directly measured, we emphasize the need for theoretical input and indirect measurements such as electron scattering, which would complement direct measurements. In this report we briefly summarize the current status of our knowledge of the neutrino cross sections and articulate needs of the experiments…

Exploring Cell Biodiversity

2015

Brain tissue is a really complex system composed of different cell types that change in shape and size. A single neuron itself has a cell body, dendrites and an axon. About 80% of cerebral tissue consists of water molecules that are confined (intra and extra cellular) in its disordered biologic networks. Using neutron scattering on IN13 we are able to explore hydrogens (H) dynamics in time scale at about 40 ps and in size scale at about 1 Å. Such characteristic make it suitable to investigate brain tissue heterogeneity exploiting hydrogens as a probe since major constituent of macromolecules and water. Elastic neutron scattering (ENS) gives information about means square displacement (MSDs)…

Exploring cell biodiversity - Neutron scattering investigation of water diffusion in complex system

2015

Scientists from biophysics, biology and medicine fields are interested in exploring and characterizing topologically cerebral tissue in order to diagnostic different diseases which affect brain in many patients [1-3]. One of the most diffuse diagnostic techniques is dMRI (diffusion magnetic resonance imaging) which extracts information about heterogeneity and asymmetries in brain tissue studying water diffusion dynamics (~80% mass constituent of tissues). The experimental limit of this technique is related to the acquisition time, TA, of the order of milliseconds. Water molecules diffuse within micrometre distance using TA as diffuse time (Eistein equation D~2TA). Cells have micrometric siz…