Here, we report the first measurement of the (e, e' p) three-body breakup reaction cross sections in helium-3 (3He) and tritium (3H) at large momentum transfer ($\langle{Q^2}\rangle$ ≈ 1.9 (GeV/c)2) ...and xB > 1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40 ≤ pmiss ≤ 500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab-initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full pmiss range for 3H and for 100 ≤ pmiss ≤ 350 MeV/c for 3He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at pmiss > 250 MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of 3He plus 3H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire pmiss range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500 MeV/c.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
We report the first measurement of the
(
e
,
e
′
p
)
three-body breakup reaction cross sections in helium-3 (
3
He
) and tritium (
3
H
) at large momentum transfer
⟨
Q
2
⟩
≈
1.9
(
GeV
/
c
)
2
...and
x
B
>
1
kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta
40
≤
p
miss
≤
500
MeV
/
c
that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within
±
20
%
, is observed between data and calculations for the full
p
miss
range for
3
H
and for
100
≤
p
miss
≤
350
MeV
/
c
for
3
He
. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at
p
miss
>
250
MeV
/
c
and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of
3
He
plus
3
H
, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire
p
miss
range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of
500
MeV
/
c
.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
We report the first measurement of the (e,e′p) reaction cross-section ratios for Helium-3 (He3), Tritium (H3), and Deuterium (d). The measurement covered a missing momentum range of ...40≤pmiss≤550MeV/c, at large momentum transfer (〈Q2〉≈1.9 (GeV/c)2) and xB>1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for He3/d and H3/d extend to just above the typical nucleon Fermi-momentum (kF≈250 MeV/c) and differ from each other by ∼20%, while for He3/H3 they agree within the measurement accuracy of about 3%. At momenta above kF, the measured He3/H3 ratios differ from the calculation by 20%−50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the He3/H3 cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the He3/H3 experimental and calculated ratios could be due to the underlying NN interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the NN interaction.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report the first longitudinal-transverse separation of the deeply virtual exclusive π^{0} electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure ...functions dσ_{L}/dt, dσ_{T}/dt, dσ_{LT}/dt, and dσ_{TT}/dt are extracted as a function of the momentum transfer to the recoil system at Q^{2}=1.75 GeV^{2} and x_{B}=0.36. The ed→edπ^{0} cross sections are found compatible with the small values expected from theoretical models. The en→enπ^{0} cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity generalized parton distributions of the nucleon. By combining these results with previous measurements of π^{0} electroproduction off the proton, we present a flavor decomposition of the u and d quark contributions to the cross section.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Purpose: This study aims to quantify the variation in dose-volume histogram (DVH) and normal tissue complication probability(NTCP) metrics for head-and-neck (HN) cancer patients when alternative ...organ-at-risk(OAR) delineations are used for treatment planning and for treatment plan evaluation. We particularly focus on the effects of daily patient positioning/setup variations(SV) in relation to treatment technique and delineation variability. Materials and Methods: We generated two-arc VMAT, 5-beam IMRT, and 9-beam IMRT treatment plans for a cohort of 209 HN patients. These plans incorporated five different OAR delineation sets, including manual and four automated algorithms. Each treatment plan was assessed under various simulated per-fraction patient setup uncertainties, evaluating the potential clinical impacts through DVH and NTCP metrics. Results: The study demonstrates that increasing SV generally reduces differences in DVH metrics between alternative delineations. However, in contrast, differences in NTCP metrics tend to increase with higher setup variability. This pattern is observed consistently across different treatment plans and delineator combinations, illustrating the intricate relationship between SV and delineation accuracy. Additionally, the need for delineation accuracy in treatment planning is shown to be case-specific and dependent on factors beyond geometric variations. Conclusions: The findings highlight the necessity for comprehensive Quality Assurance programs in radiotherapy, incorporating both dosimetric impact analysis and geometric variation assessment to ensure optimal delineation quality. The study emphasizes the complex dynamics of treatment planning in radiotherapy, advocating for personalized, case-specific strategies in clinical practice to enhance patient care quality and efficacy in the face of varying SV and delineation accuracies.
This study aims to quantify the variation in dose-volume histogram (DVH) and normal tissue complication probability(NTCP) metrics for head-and-neck (HN) cancer patients when alternative ...organ-at-risk(OAR) delineations are used for treatment planning and for treatment plan evaluation. We particularly focus on the effects of daily patient positioning/setup variations(SV) in relation to treatment technique and delineation variability.
We generated two-arc VMAT, 5-beam IMRT, and 9-beam IMRT treatment plans for a cohort of 209 HN patients. These plans incorporated five different OAR delineation sets, including manual and four automated algorithms. Each treatment plan was assessed under various simulated per-fraction patient setup uncertainties, evaluating the potential clinical impacts through DVH and NTCP metrics.
The study demonstrates that increasing SV generally reduces differences in DVH metrics between alternative delineations. However, in contrast, differences in NTCP metrics tend to increase with higher setup variability. This pattern is observed consistently across different treatment plans and delineator combinations, illustrating the intricate relationship between SV and delineation accuracy. Additionally, the need for delineation accuracy in treatment planning is shown to be case-specific and dependent on factors beyond geometric variations.
The findings highlight the necessity for comprehensive Quality Assurance programs in radiotherapy, incorporating both dosimetric impact analysis and geometric variation assessment to ensure optimal delineation quality. The study emphasizes the complex dynamics of treatment planning in radiotherapy, advocating for personalized, case-specific strategies in clinical practice to enhance patient care quality and efficacy in the face of varying SV and delineation accuracies.
A TiO2/GO/CuFe2O4 heterostructure photocatalyst is fabricated by a simple and low-cost ball-milling pathway for enhancing the photocatalytic degradation of chlorinated pesticides under UV light ...irradiation. Based on the advantages of graphene oxide, TiO2, and CuFe2O4, the nanocomposite exhibited visible light absorption, magnetic properties, and adsorption capacity. Integrated analyses using XRD, SEM, TEM, and UV-visible techniques demonstrated that the nanocomposite exhibited a well-defined crystalline phase, sizes of 10–15 nm, and evincing a visible light absorption feature with an optical bandgap energy of 2.4 eV. The photocatalytic degradations of 17 different chlorinated pesticides (persistent organic pollutants) were assayed using the prepared photocatalyst. The photocatalytic activity of the nanocomposite generated almost 96.5% photocatalytic removal efficiency of typical pesticide DDE from water under UV irradiation. The superior photocatalytic performance was exhibited by the TiO2/GO/CuFeO4 catalyst owing to its high adsorption performance and separation efficiency of photo-generated carriers. The photocatalyst was examined in 5 cycles for treating uncolored pesticides with purposeful separation using an external magnetic field.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
Pyrogallol is widely used in several industrial applications and can subsequently contaminate aquatic ecosystems. Here, we report for the first time the presence of pyrogallol in wastewater in Egypt. ...Currently, there is a complete lack of toxicity and carcinogenicity data for pyrogallol exposure in fish. To address this gap, both acute and sub-acute toxicity experiments were conducted to determine the toxicity of pyrogallol in catfish (Clarias gariepinus). Behavioral and morphological endpoints were evaluated, in addition to blood hematological endpoints, biochemical indices, electrolyte balance, and the erythron profile (poikilocytosis and nuclear abnormalities). In the acute toxicity assay, it was determined that the 96 h median-lethal concentration (96 h-LC50) of pyrogallol for catfish was 40 mg/L. In sub-acute toxicity experiment, fish divided into four groups; Group 1 was the control group. Group 2 was exposed to 1 mg/L of pyrogallol, Group 3 was exposed to 5 mg/L of pyrogallol, and Group 4 was exposed to 10 mg/L of pyrogallol. Fish showed morphological changes such as erosion of the dorsal and caudal fins, skin ulcers, and discoloration following exposure to pyrogallol for 96 h. Exposure to 1, 5, or 10 mg/L pyrogallol caused a significant decrease in hematological indices, including red blood cells (RBCs), hemoglobin, hematocrit, white blood cells (WBC), thrombocytes, and large and small lymphocytes in a dose-dependent manner. Several biochemical parameters (creatinine, uric acid, liver enzymes, lactate dehydrogenase, and glucose) were altered in a concentration dependent manner with short term exposures to pyrogallol. Pyrogallol exposure also caused a significant concentration-dependent rise in the percentage of poikilocytosis and nuclear abnormalities of RBCs in catfish.
In conclusion, our data suggest that pyrogallol should be considered further in environmental risk assessments of aquatic species.
Display omitted
•The presence of pyrogallol was detected for the first time in wastewater in Egypt.•The 96 h median-lethal concentration (LC50) of pyrogallol for catfish was 40 mg/L.•Exposure to 1, 5, 10 mg/L of pyrogallol increased the abundance of neutrophils and eosinophils.•Pyrogallol decreased several blood electrolyte indices.•Pyrogallol exposure caused a concentration-dependent rise in poikilocytosis of RBCs in catfish.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Synchrotron radiation‐based techniques X‐ray absorption near‐edge structure (XANES) and X‐ray fluorescence (XRF) combined with inductively coupled plasma‐mass spectrometry (ICP‐MS) were used for the ...assessment of heavy metals concentrations as well as lead (Pb) and nickel (Ni) speciation in airborne particulate matter (PM10) over two residential sites in Greater Cairo. Nineteen 24 h high‐volume samples collected at Giza (G) Square and Helwan (H) University (Egypt) were selected for this study. Mean concentrations of heavy metals in PM10 at both sites were found to have the same descending order of Pb > Cu > Ni > Cd > Co > As, of which concentrations of Pb, Cu, Ni and Cd in H samples were higher than those in G samples. For Pb, synchrotron‐based XRF results were in good agreement with concentrations obtained by ICP‐MS. The XANES spectra of PM10 at the Pb L2‐edge and Ni K‐edge were compared with those of Pb and Ni in model standard compounds to provide information on the potential oxidation states as well as the chemical forms of those elements. The data show that Pb has similar chemical environments in both series G and H with the predominance of Pb2+ oxidation state. Nickel was found as Ni(OH)2, NiO and Ni metal in the analyzed samples. However, the content of Ni in the background filter shows a very strong interference with that of the collected PM10. Carcinogenic and non‐carcinogenic risks resulting from the inhalation of the studied heavy metals were assessed for children and adult residents and were found below the safe limits, at both sites.
XANES and X‐ray fluorescence combined with inductively coupled plasma‐mass spectrometry were used to quantify and identify heavy metals concentrations as well as the chemical speciation of Pb and Ni, which have considerable public health impacts in Egypt.
Full text
Available for:
FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
