168 research outputs found
Synthesis and spectroscopic characterization of selected water-soluble ligands based on 1,10-phenanthroline core
Water-soluble ligands based on a 1,10-phenanthroline core are relatively poorly studied compounds. Developing efficient and convenient syntheses of them would result in new interesting applications because of the importance of 1,10-phenanthrolines. In this manuscript, we describe novel and practical ways to introduce a carboxyl and, for the first time, a phenol and dithiocarboxyl group under mild reaction conditions. This strategy enables highly efficient and practical synthesis of suitable organosulfur compounds with high added value, high chemoselectivity, and a broad substrate range. We present the selective conversion of a hydroxydialdehyde in the form of 10-hydroxybenzo[h]quinoline-7,9-dicarbaldehyde into its derivative, unique hydroxydicarboxylic acid, by an oxidation procedure, giving 10-hydroxybenzo[h]quinoline-7,9-dicarboxylic acid. A similar procedure resulted in the formation of 9-methyl-1,10-phenanthroline-2-carboxylic acid by oxidation of commercially available neocuproine. An alternative method of obtaining 1,10-phenanthroline derivatives possessing carboxylic acid group can be based on the hydrolysis of ester or nitrile groups; however, this synthesis leads to unexpected products. Moreover, we apply Perkin condensation to synthesize a vinyl (or styryl) analog of 1,10-phenanthroline derivatives with phenol function. This reaction also demonstrates a new, simple, and efficient strategy for converting methyl derivatives of 1,10-phenanthroline. We anticipate that the new way of converting methyl will find wide application in chemical synthesis
Ratunku! or just tunku! : evidence for the reliability and concurrent validity of the Language Use Inventory : LUI-Polish
Purpose: To date, there is no tool for assessing early pragmatic development of Polish-speaking children. This study aimed to adapt to Polish a standardized parent report measure, the Language Use Inventory (LUI; O’Neill, 2009, in order to enable cross-cultural comparisons and to
use the LUI-Polish to screen for pragmatic development in children 18-47 months of age. We concentrated on the sociocultural and functional adaptation of LUI and aimed to demonstrate its reliability, developmental sensitivity, and concurrent validity. Method: Parents completed an online version of LUIPolish, longitudinally at 3 time points (when the child was 20, 32, and 44 months old). In addition, parents completed the Polish adaptations of the Questionnaire for Communication and Early Language at 22 months and the Language Development Survey at 24 months. Children’s spontaneous speech was assessed at 24 months, and their expressive and receptive vocabulary was assessed at 36 months.
Results: All 3 parts of the LUI-Polish (Gestures, Words, and Sentences) showed very good levels of internal consistency at each time point. Significant correlations were observed between all parts of the LUI-Polish at all 3 measurement time points. The expected developmental trajectory was observed for boys and girls providing evidence of its developmental sensitivity for children between the ages of 2 and 4 years: an increase with age in the total score (due to an increase in Words and Sentences) and a decrease in Gestures. Supporting concurrent validity, significant correlations were found between children’s performance on (a) the LUI-Polish at 20 months and the Questionnaire for Communication and Early Language at 22 months as well as the Language Development Survey and spontaneous speech measures at 24 months and (b) the LUI-Polish at 32 months and the 2 measures of vocabulary comprehension and production at 36 months. Conclusion: The Polish adaptation of the LUI demonstrated good psychometric properties that provide a sound basis for cross-cultural comparisons and further research toward norming of the LUI-Polish. Moreover, the expected developmental trajectory in the pragmatic development of Polish children was observed
Measurement of the Generalized Polarizabilities of the Proton in Virtual Compton Scattering
We propose to conduct a measurement of the Virtual Compton Scattering
reaction in Hall C that will allow the precise extraction of the two scalar
Generalized Polarizabilities (GPs) of the proton in the region of
to . The Generalized Polarizabilities
are fundamental properties of the proton, that characterize the system's
response to an external electromagnetic (EM) field. They describe how easily
the charge and magnetization distributions inside the system are distorted by
the EM field, mapping out the resulting deformation of the densities in the
proton. As such, they reveal unique information regarding the underlying system
dynamics and provide a key for decoding the proton structure in terms of the
theory of the strong interaction that binds its elementary quark and gluon
constituents together. Recent measurements of the proton GPs have challenged
the theoretical predictions, particularly in regard to the electric
polarizability. The magnetic GP, on the other hand, can provide valuable
insight to the competing paramagnetic and diamagnetic contributions in the
proton, but it is poorly known within the region where the interplay of these
processes is very dynamic and rapidly changing.The unique capabilities of Hall
C, namely the high resolution of the spectrometers combined with the ability to
place the spectrometers in small angles, will allow to pin down the dynamic
signature of the GPs through high precision measurements combined with a fine
mapping as a function of . The experimental setup utilizes standard Hall C
equipment, as was previously employed in the VCS-I (E12-15-001) experiment,
namely the HMS and SHMS spectrometers and a 10 cm liquid hydrogen target. A
total of 59 days of unpolarized 75 electron beam with energy of 1100
MeV (6 days) and 2200 MeV (53 days) is requested for this experiment
Density Changes in Low Pressure Gas Targets for Electron Scattering Experiments
A system of modular sealed gas target cells has been developed for use in
electron scattering experiments at the Thomas Jefferson National Accelerator
Facility (Jefferson Lab). This system was initially developed to complete the
MARATHON experiment which required, among other species, tritium as a target
material. Thus far, the cells have been loaded with the gas species 3H, 3He,
2H, 1H and 40Ar and operated in nominal beam currents of up to 22.5 uA in
Jefferson Lab's Hall A. While the gas density of the cells at the time of
loading is known, the density of each gas varies uniquely when heated by the
electron beam. To extract experimental cross sections using these cells,
density dependence on beam current of each target fluid must be determined. In
this study, data from measurements with several beam currents within the range
of 2.5 to 22.5 uA on each target fluid are presented. Additionally, expressions
for the beam current dependent fluid density of each target are developed.Comment: 8 pages, 12 figures, 4 table
The Solenoidal Large Intensity Device (SoLID) for JLab 12 GeV
The Solenoidal Large Intensity Device (SoLID) is a new experimental apparatus
planned for Hall A at the Thomas Jefferson National Accelerator Facility
(JLab). SoLID will combine large angular and momentum acceptance with the
capability to handle very high data rates at high luminosity. With a slate of
approved high-impact physics experiments, SoLID will push JLab to a new limit
at the QCD intensity frontier that will exploit the full potential of its 12
GeV electron beam. In this paper, we present an overview of the rich physics
program that can be realized with SoLID, which encompasses the tomography of
the nucleon in 3-D momentum space from Semi-Inclusive Deep Inelastic Scattering
(SIDIS), expanding the phase space in the search for new physics and novel
hadronic effects in parity-violating DIS (PVDIS), a precision measurement of
production at threshold that probes the gluon field and its
contribution to the proton mass, tomography of the nucleon in combined
coordinate and momentum space with deep exclusive reactions, and more. To meet
the challenging requirements, the design of SoLID described here takes full
advantage of recent progress in detector, data acquisition and computing
technologies. In addition, we outline potential experiments beyond the
currently approved program and discuss the physics that could be explored
should upgrades of CEBAF become a reality in the future.Comment: This white paper for the SoLID program at Jefferson Lab was prepared
in part as an input to the 2023 NSAC Long Range Planning exercise. To be
submitted to J. Phys.
First Measurement of the Ti (e,e′) X Cross Section at Jefferson Lab
To probe CP violation in the leptonic sector using GeV energy neutrino beams in current and future experiments using argon detectors, precise models of the complex underlying neutrino and antineutrino interactions are needed. The E12-14-012 experiment at Jefferson Lab Hall A was designed to perform a combined analysis of inclusive and exclusive electron scatterings on both argon (N=22) and titanium (Z=22) nuclei using GeV-energy electron beams. The measurement on titanium nucleus provides essential information to understand the neutrino scattering on argon, large contribution to which comes from scattering off neutrons. Here we report the first experimental study of electron-titanium scattering as double-differential cross section at beam energy E=2.222 GeV and electron-scattering angle θ=15.541^{∘}, measured over a broad range of energy transfer, spanning the kinematical regions in which quasielastic scattering and delta production are the dominant reaction mechanisms. The data provide valuable new information needed to develop accurate theoretical models of the electromagnetic and weak cross sections of these complex nuclei in the kinematic regime of interest to neutrino experiments.National Science Foundation (U.S.) (CAREER Grant PHY-1352106
First Measurement of the Ti Cross Section at Jefferson Lab
To probe CP violation in the leptonic sector using GeV energy neutrino beams
in current and future experiments using argon detectors, precise models of the
complex underlying neutrino and antineutrino interactions are needed. The
E12-14-012 experiment at Jefferson Lab Hall A was designed to perform a
combined analysis of inclusive and exclusive electron scatterings on both argon
() and titanium () nuclei using GeV energy electron beams. The
measurement on titanium nucleus provides essential information to understand
the neutrino scattering on argon, large contribution to which comes from
scattering off neutrons. Here we report the first experimental study of
electron-titanium scattering as double differential cross section at beam
energy GeV and electron scattering angle deg,
measured over a broad range of energy transfer, spanning the kinematical
regions in which quasielastic scattering and delta production are the dominant
reaction mechanisms. The data provide valuable new information needed to
develop accurate theoretical models of the electromagnetic and weak cross
sections of these complex nuclei in the kinematic regime of interest to
neutrino experiments.Comment: 6 pages, 5 figures. Version published in Physical Review
Measurement of the Ar(e,e p) and Ti(e,e p) cross sections in Jefferson Lab Hall A
The E12-14-012 experiment, performed in Jefferson Lab Hall A, has collected
exclusive electron-scattering data (e,ep) in parallel kinematics using
natural argon and natural titanium targets. Here, we report the first results
of the analysis of the data set corresponding to beam energy of 2,222 MeV,
electron scattering angle 21.5 deg, and proton emission angle -50 deg. The
differential cross sections, measured with 4% uncertainty, have been
studied as a function of missing energy and missing momentum, and compared to
the results of Monte Carlo simulations, obtained from a model based on the
Distorted Wave Impulse Approximation.Comment: 14 pages, 8 figures (submitted to PRC
Measurement of the Cross Sections for Inclusive Electron Scattering in the E12-14-012 Experiment at Jefferson Lab
The E12-14-012 experiment performed at Jefferson Lab Hall A has collected inclusive electron-scattering data for different targets at the kinematics corresponding to beam energy 2.222 GeV and scattering angle 15.54°. Here we present a comprehensive analysis of the collected data and compare the double-differential cross sections for inclusive scattering of electrons, extracted using solid targets (aluminum, carbon, and titanium) and a closed argon-gas cell. The data extend over broad range of energy transfer, where quasielastic interaction, Δ-resonance excitation, and inelastic scattering yield contributions to the cross section. The double-differential cross sections are reported with high precision (∼3%) for all targets over the covered kinematic range
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