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WOS: 000471733500002 The gamma ray photon interaction parameters for different samples including calcium silicide, magnesium silicide, magnesium boride, calcium hexaboride, aluminum oxide, and titanium dioxide were investigated. For this aim, the mass attenuation coefficients for these samples were measured by the transmission geometry at 14 energies values (ie., E is an element of [81,1333] keV) and the results were compared with those acquired from the WinXCOM software. From the present samples, calcium silicide and magnesium boride have the highest and lowest effective atomic numbers, respectively. Besides, the effective atomic number values almost remain constant for magnesium silicide. The half value layer results showed that as the energy increases, the probability of photon interaction with the ceramic sample decreases, thus more gamma photons can penetrate the ceramics.

We have investigated numerically the ability to inhibit spike protein from SARS-CoV-2 to attach and inter the host cell when exposed to energetic photons. The Geometric Progression fitting method have been adopted to calculate the equivalent atomic number for photon energy absorption (Zeq), exposure and absorption buildup factors in the energy range E∈ [15–300] keV for the S2-subunit in the spike protein. The buildup factors have shown a peak value at adsorption resonance energy between 36–60 eV per amino acid of the S2-subunit which depends on the mean free path of the photon within the protein structure and the type of mutation. The resonance energies (between UV and X-ray range) have been found to depend on the protein molecular composition. This opens the possibility of using energetic photons to break up the S2-subunit into small fragments. Our results may contribute to the continues racing for finding noninvasive technique for medical trials using radiotherapy treatment for the COVID-19 virus.

Ternary tellurite glasses with composition 20WO3-xBi2O3- (80-x) TeO2 (x = 10, 15, 20 and 25 mol%) were synthesized by conventional quenching method from pure oxides. Amorphous state of the prepared samples was checked by X-ray diffraction. The variation in the density values (ρ) and molar volume (Vm) oxygen packing density (OPD) and ion concentration (N) showed the influence of Bi2O3 on glass structure. The various optical properties such as optical band gap (Eopt), refractive index (n), molar refraction (Rm), cationic polarizability (αm) and optical basicity (∧) were calculated and are discussed in terms of structural changes. These optical properties have been observed to vary with Bi2O3 concentration. FTIR investigation shows the glasses contain TeO4, BiO6 and WO4 basic structural units. Additionally, different shielding parameters such as effective atomic number, radiation protection efficiency, mean free path, half value layer and exposure buildup factor were calculated in order to effectively use these glasses simultaneously in optical-based devices with high radiation shielding performance. The results showed that the mass attenuation coefficient and effective atomic number values of WTBi4 glass sample which contains the higher Bi2O3 concentration were the maximum at the selected energies. The mean free path of the prepared glasses was compared to different glasses, while the half value layer of the prepared glasses was compared to different types of concretes.

CdTe thin films of 50 nm thickness have been deposited on glass substrates by thermal vacuum evaporation technique and the γ-irradiation effect on their optical properties has been investigated. Transmittance and reflectance have been measured at normal incidence, in the visible region from 400 to 700 nm, and were used to evaluate the optical parameters and the band gap energy for CdTe thin films before and after γ-irradiation. Structure and surface morphology before and after γ-irradiation were investigated using X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) respectively. XRD pattern of the as-deposited CdTe film shows an amorphous nature. Crystalline structure was observed to improve when samples were exposed to γ-irradiation at doses from 40 – 120 kGy in the (111) plane of the cubic zinc-blende structure. SEM shows a change in the surface morphology of CdTe films as a consequence of γ-irradiation compared to as-deposited sample. The optical properties such as refractive index, extinction coefficient, dielectric constant were found to decrease with the increase of the dose of γ-irradiation. Energy band gap was found to decrease from 2.47 eV for the as-deposited down to 2.20 eV for 120 kGy (blue shift compared to bulk CdTe), that was attributed to the small thin film thickness.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17607

In myelodysplastic syndromes (MDS), somatic mutations occur in five major categories: RNA splicing, DNA methylation, activated cell signaling, myeloid transcription factors, and chromatin modifiers. Although many MDS cases harbor more than one somatic mutation, in general, there is mutual exclusivity of mutated genes within a class. In addition to the prognostic significance of individual somatic mutations, more somatic mutations in MDS have been associated with poor prognosis. Prognostic assessment remains a critical component of the personalization of care for patient with MDS because treatment is highly risk adapted. Multiple methods for risk stratification are available with the revised International Prognostic Scoring System (IPSS-R), currently considered the gold standard. Increasing access to myeloid gene panels and greater evidence for the diagnostic and predictive value of somatic mutations will soon make sequencing part of the standard evaluation of patients with MDS. In the absence of formal guidelines for their prognostic use, well-validated mutations can still refine estimates of risk made with the IPSS-R. Not only are somatic gene mutations advantageous in understanding the biology of MDS and prognosis, they also offer potential as biomarkers and targets for the treatment of patients with MDS. Examples include deletion 5q, spliceosome complex gene mutations, and TP53 mutations.

A Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) apparatus has been constructed and operated cooperatively by the Atomic and Molecular Physics Laboratory in the Physics Department at the Hashemite University, Jordan, and the Atomic and Molecular Physics Group at the 4.75 MeV Van de Graaff Accelerator Facility at the University of Jordan. This COLTRIMS imaging system allows the investigation of the dynamics of various ion impact induced atomic and molecular interactions and fragmentations. The performance of the COLTRIMS system was tested by carrying out preliminary studies of two collision systems. In the first study, electron capture processes in the He 2+ –Ne collision system at 0.25 and 1.0 MeV impact energies were investigated. Significant simultaneous electron capture and target excitation has been observed for the 0.25 MeV as opposed to the 1.0 MeV impact energy. In the other study, projectile single electron loss and simultaneous single target ionization in the O + –He collision system was studied at three different projectile impact energies: 0.6, 1.45 and 2 MeV. Enhancement of the electron–electron contribution to projectile electron loss with increasing collision energy has been observed.

The AC conductivity of nickel phthalocyanine octacarboxylic acid was investigated from 100 Hz to 1 MHz and temperature from 290 to 423 K. The AC conductivity was found to vary with frequency (σ(f)) and form two dispersion regions; the associated exponent factor “s” values were found to vary from 1.17 to 1.34 and from 0.42 to 0.67 (

The concentrations of elements in pharmaceuticals derived from plant seeds were determined by energy dispersive X-ray fluorescence. The concentrations of Ca, Si, Cl, K, S, Ti, Cr, Mn, Fe, P, Cu, Zn, Br, Rb, Sr, Hg, and Zr were quantified; only Si (10 ± 1 to 70,000 ± 110 mg kg−1), S (10 ± 2 to 12,4000 ± 243 mg kg−1), K (4,000 ± 58 to 24,000 ± 70 mg kg−1), Ca (2200 ± 35 to 87,000 ± 150 mg kg−1), Mn (21 ± 4 to 1956 ± 17 mg kg−1), and Fe (100 ± 7 to 5150 ± 70 mg kg−1) were present in all samples. These results may validate the use of these pharmaceuticals for the treatment of disease due to high concentrations of essential elements Mn, Ca, Mn, K, Mg, Zn, Cl, Fe, and P. Mercury was present in some products below standard values. The results also have quality control applications because of the widespread use of these pharmaceuticals.

Nuclear motion in the N1s(-1)4a core-excited state of ammonia is investigated by studying the angular anisotropy of fragments produced in the decay of the highly excited molecule and compared with predictions from ab initio calculations. Two different fragmentation channels (H(+)/NH2(+) and H(+)/NH(+)/H) reveal complex nuclear dynamics as the excitation photon energy is tuned through the 4a1 resonance. The well-defined angular anisotropy of the fragments produced in the dissociation of the molecular dication species suggests a very rapid nuclear motion and the time scale of the nuclear dynamics is limited to the low fs timescale.

We experimentally study $2p$ photoionization of neon dimers (${\mathrm{Ne}}_{2}$) at a photon energy of $h\ensuremath{\nu}=36.56\text{ }\text{ }\mathrm{eV}$. By postselection of ionization events which lead to a dissociation into ${\mathrm{Ne}}^{+}+\mathrm{Ne}$ we obtain the photoelectron angular emission distribution in the molecular frame. This distribution is symmetric with respect to the direction of the charged vs neutral fragment. It shows an inverted Cohen-Fano double slit interference pattern of two spherical waves emitted coherently but with opposite phases from the two atoms of the dimer.

Analysis of the electrons ionized from water dimers suggests that the energy absorbed by one molecule is rapidly transmitted to the second molecule from which the electron is ejected. This process, referred to as intermolecular Coulombic decay, is a qualitatively different source of low-energy electrons to conventional direct ionization processes. At the transition from the gas to the liquid phase of water, a wealth of new phenomena emerge, which are absent for isolated H2O molecules. Many of those are important for the existence of life, for astrophysics and atmospheric science. In particular, the response to electronic excitation changes completely as more degrees of freedom become available. Here we report the direct observation of an ultrafast transfer of energy across the hydrogen bridge in (H2O)2 (a so-called water dimer). This intermolecular coulombic decay leads to an ejection of a low-energy electron from the molecular neighbour of the initially excited molecule. We observe that this decay is faster than the proton transfer that is usually a prominent pathway in the case of electronic excitation of small water clusters and leads to dissociation of the water dimer into two H2O+ ions. As electrons of low energy (∼0.7–20 eV) have recently been found to efficiently break-up DNA constituents1,2, the observed decay channel might contribute as a source of electrons that can cause radiation damage in biological matter.

We have used the cold target recoil ion momentum spectroscopy imaging technique to investigate dissociative ionization of H2 by 25 keV proton impact. A kinematically complete picture of the dissociative ionization dynamics for slow proton collision has been obtained. The results show a strong impactparameter dependence of the fragmentation process of H2. This clearly emerged in the energy distributions of the H + ions generated for different impact parameters. At large impact parameters the H + ions equally share the energy liberated in the collision whereas at small impact parameters, the energy sharing is quite asymmetric. We also observed a strong dependence of the electron emission on molecular alignment. The momentum distribution of the emitted electron generated for a fixed-in-space H2 molecule displays that the electrons are more likely to be emitted perpendicular to the molecular axis.

The zero-degree ejected-electron spectrum for protons incident on He at 25 keV is examined experimentally using the COLTRIMS technique. The momentum distribution of the emitted electrons for the transfer ionization (TI) reaction channel is measured in coincidence with the momentum vectors of the recoil ion and the scattered projectile. The momentum distribution of the electrons emitted around zero degree in the forward direction for the TI reaction channel shows two prominent structures: the electron-capture-to-the-continuum (ECC) peak and the saddle-point peak. From the measured fully differential electron emission cross sections with respect to the scattering plane we can deduce that the main ECC formation mechanism is electron promotion via quasimolecular orbitals.

The single ionization (SI) and the transfer ionization (TI) of H2 have been investigated utilizing the Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) reaction microscope. Continuum electron velocity spectra have been measured for experimentally determined nuclear motion. Electron velocity distributions for the SI of H2 show that the ejected electrons lie mainly in the scattering plane where their velocities were found to lie between those of the recoiling target and the scattered projectile. In addition to a group of electrons seen in SI saddle electrons group, the electron velocity spectra for TI of H2 unveiled the existence of another group of electrons with different structure. These electrons were emitted with velocities greater than the projectile velocity and found to result from a narrow range of impact parameters. These fast forward electrons reveal a substantial amount of out-of-plane scattering. 2005 Elsevier B.V. All rights reserved.

The ion momentum spectra for nonsequential double ionization of rare gases (He, Ne and Ar) in 23 fs 795 nm laser pulses were measured in the intensity range 0.075–1.25 PW cm−2. In the studies published, confusing differences in the shape of momentum distributions among different targets are consistently explained within a recollision scenario: excitation during recollision plus subsequent field ionization, not implemented in most theoretical approaches, evidently plays a decisive role for He and Ar nonsequential double ionization whereas it plays only a minor role for Ne.

Electrical properties of bis-ethylenediamine Co(II), Co(III) and Co(II–III) mixed valence complexes and polyethylenediaminecarbosilazane (PEDCSZ) [Co(II), Co(III) and Co(II–III)] macromolecules were measured at room temperature in a frequency range between 1 Hz and 106 Hz. Electrical modulus, permittivity and ac conductivity were calculated using ac impedance and phase-angle measurements. It was found that the overall conductivity of PEDCSZ macromolecules with Co is much higher than that for Co monomers. In addition, the conductivity of PEDCSZ Co(III) and Co(II–III) mixed valence compounds are higher than those containing Co(II) where the electronic conduction is dominant. The relaxation time increases from about 2.7 × 10−6 s for Co(II) chloride to a value of 2.9 × 10−4 s for Co(II–III) chloride monomers. Copyright © 2003 Society of Chemical Industry

A new spectrometer has been developed based on the combination of standard time-of-flight technique and position sensitive delay line detectors. The basic features of the spectrometer, particularly of the multi-hit capable detector, are described. To demonstrate the performance of this new system, the dynamic emission characteristics, i.e. the threedimensional velocity distribution, of desorbed H þ from Al target by Ar 0 impact (570 keV) is presented. It is found that the desorption yield is maximum for radial and axial emission velocities at 1.2 and 12 km/s respectively, corresponding to 1.5 eV ions emitted at 57 to normal (following the projectile radial direction). The initial energy distribution spreads out over 16 eV. 2002 Elsevier Science B.V. All rights reserved.

The transfer ionization of He and H2 by incident He2+ was investigated at 0.81 au impact velocity employing cold target recoil ion momentum spectroscopy. In addition to electrons in the saddle point region between the target and projectile forming two `jets' separated by a valley along the projectile beam axis, we find a new group of electrons moving with a velocity greater than the projectile velocity. These new fast forward electrons result from a narrow range of impact parameters and contribute up to 40% to the total cross section of the transfer ionization process.

In this paper, we study single and double ionizations of N2O in a short elliptically polarized 800 nm laser pulse using the COLTRIMS technique. The molecular-frame photoelectron angular distribution and the ion sum-momentum distribution of single and double ionizations of N2O molecules are reported for the single ionization dissociative channel NO[Formula: see text] + N and the double ionization dissociative channel NO[Formula: see text] + N[Formula: see text]. The ionizations of multiple orbitals for the two studied dissociative channels were identified via studying the orientation dependent ionization rates for their KERs. The results show that the shape of the ionizing orbitals governs the single and double ionization processes of N2O.

The dynamics of singly ionizing proton-helium collisions have been studied experimentally for several energies of the projectile (0.2, 0.5, 1.0 and 1.3 MeV) with the technique of cold target recoil-ion momentum spectroscopy (COLTRIMS). The complete final-state distribution in momentum space of all three particles was determined by measuring the three momentum components of the emitted electron and the coincident recoiling target ion. The momentum transfer and energy loss of the outgoing projectile was determined by momentum and energy conservation laws. Doubly differential cross sections of the kinematically complete experimental investigation are presented. The present data are compared with results from fast highly charged heavy-ion impact experiments.

We demonstrate experimentally the difference between a sequential interaction of a femtosecond laser field with two electrons and a nonsequential process of double ionization mediated by electron-electron correlation. This is possible by observing the momentum distribution of doubly charged argon ions created in the laser field. In the regime of laser intensities where the nonsequential process dominates, an increase in laser power leads to an increase in the observed ion momenta. At the onset of the sequential process, however, a higher laser power leads to colder ions. The momentum distributions of the ions from the sequential process can be modelled by convolving the single-ionization distribution with itself.

The activity concentrations of naturally occurring radionuclides ((238)U, (226)Ra, (228)Ra, (210)Pb and (40)K) in Jordanian phosphate ore, fertilizer material and phosphogypsum piles were investigated. The results show the partitioning of radionuclides in fertilizer products and phosphogypsum piles. The outcome of this study will enrich the Jordanian radiological map database, and will be useful for an estimation of the radiological impact of this industrial complex on the immediate environment. The activity concentration of (210)Pb was found to vary from 95 +/- 8 to 129 +/- 8 Bq kg(-1) with a mean value of 111 +/- 14 Bq kg(-1) in fertilizer samples, and from 364 +/- 8 to 428 +/- 10 Bq kg(-1) with a mean value of 391 +/- 30 Bq kg(-1) in phosphogypsum samples; while in phosphate wet rock samples, it was found to vary between 621 +/- 9 and 637 +/- 10 Bq kg(-1), with a mean value of 628 +/- 7 Bq kg(-1). The activity concentration of (226)Ra in fertilizer samples (between 31 +/- 4 and 42 +/- 5 Bq kg(-1) with a mean value of 37 +/- 6 Bq kg(-1)) was found to be much smaller than the activity concentration of (226)Ra in phosphogypsum samples (between 302 +/- 8 and 442 +/- 8 Bq kg(-1) with a mean value of 376 +/- 62 Bq kg(-1)). In contrast, the activity concentration of (238)U in fertilizer samples (between 1011 +/- 13 and 1061 +/- 14 Bq kg(-1) with a mean value of 1033 +/- 22 Bq kg(-1)) was found to be much higher than the activity concentration of (238)U in phosphogypsum samples (between 14 +/- 5 and 37 +/- 7 Bq kg(-1) with a mean value of 22 +/- 11 Bq kg(-1)). This indicates that (210)Pb and (226)Ra show similar behaviour, and are concentrated in phosphogypsum piles. In addition, both isotopes enhanced the activity concentration in phosphogypsum piles, while (238)U enhanced the activity concentration in the fertilizer. Due to the radioactivity released from the phosphate rock processing plants into the environment, the highest collective dose commitment for the lungs was found to be 1.02 person nGy t(-1). Lung tissue also shows the highest effect due the presence of (226)Ra in the radioactive cloud (0.087 person nGy t(-1)).

The dissociative electron transfer from He into 10 keV H2+ was measured in a kinematically complete experiment by using the cold target recoil ion momentum spectroscopy imaging technique in combination with a highly resolving molecular fragment imaging technique. The electron transfer into the dissociative b(3)Sigma+_(u) state of H2 could be selected by kinematic conditions. We find a striking double slit interference pattern in the transverse momentum transfer which we can modify by selecting different internuclear distances. Compared to an optical double slit, interference minima and maxima are interchanged. The latter is the result of a phase shift in the electronic part of the wave function.

Using cold target recoil ion momentum spectroscopy (COLTRIMS) we have investigated the production of one free electron in slow He{sup 2+}+He(1s{sup 2}) collisions. At projectile velocities between 0.6 and 1.06 a.u. (9-28 keV/u), the fully differential cross section was measured state selective with respect to the second electron, which is bound either at the target or the projectile. We provide a comprehensive data set comprising state selective total cross section, scattering angle dependent single differential cross sections, and fully differential cross section. We show that the momentum distribution of the electron in the continuum image the relevant molecular orbitals for the reaction channel under consideration. By choosing the bound electron final state at the target or projectile and the impact parameter we can select these orbitals and manipulate their relative phase.

We studied slow dissociative collisions between He and diatomic molecular ions using Cold Target Recoil Momentum Spectroscopy (COLTRIMS) technique in combination with fragment imaging technique. All final state momentum components, as well as the masses of the molecular fragments were determined. As the complete information on the kinematics is available, we are able to calculate the final state binding energy as well as the kinetic energy of the molecular fragments in the molecular center of mass system (kinetic energy release). The results show that the probability of the reaction channels is strongly dependent on the relative geometric orientation of the participants.

The natural radioactivity due to the presence of (226)Ra, (232)Th and (40)K in selected building materials used in Jordanian building constructions has been measured using gamma-ray spectrometer with a Hyper Pure germanium detector. The average activity concentrations observed in different building materials ranged from 27.7 +/- 7.5 to 70.4 +/- 2.8, 5.9 +/- 0.67 to 32.9 +/- 3.9 and 30.8 +/- 0.87 to 58.5 +/- 1.5 for (226)Ra, (232)Th and (40)K, respectively. The activity concentrations of (226)Ra measured in fine aggregates was found to be among the highest values obtained in this work. The ranges of the calculated Ra-equivalent were found to be lower than those values recommended for construction materials (370 Bq kg(-1)). The average internal and external hazard indices were found to be

Experimental studies of core-excited molecules using three-dimensional multi particle momentum imaging are presented where bond rearrangement processes in dication species are analysed. The aim of the study is to understand the relation between the geometric changes associated with core-excited states and the kinetic energy released in particular molecular dissociation processes. The kinematics of individual fragmentation channels are studied by fully three-dimensional momentum imaging of fragments in coincidence. Examples are presented where the high efficiency of the instrument and the fully three-dimensional momentum capabilities are exploited to understand nuclear motion leading to bond rearrangement in core-excited states. We identify bond-rearrangement processes in water, carbonyl sulphide and acetylene which are initiated in the core-excited state. In water this is evidenced by the H-2(+)/O+ ion pair, and in carbonyl sulphide the OS++C+ pair is the fingerprint of this reaction. In acetylene the H-2(+) + C-2(+) ion pair indicates a molecular geometry that changes from linear to strongly bent. We measure the angular distribution of all fragments and fragment pairs and for the bond rearrangement processes in water and in core-excited acetylene the angular distribution of fragments suggests that the bond rearrangement is very rapid. (Less)

We report on the experimental observation of an abrupt rise in the longitudinal momentum distribution of recoil ions created in proton helium collision. The details of this structure can be related to electrons traveling with the velocity of the projectile [electron capture to the continuum (ECC)]. The longitudinal as well as the transverse distribution of the recoil ions can be explained as a continuation of the momentum distribution from ions resulting from electron capture illustrating the smooth transition from the capture to bound states of the projectile to the ECC. Fil: Weber, Th.. Institut für Kernphysik; Alemania Fil: Khayyat, Kh.. Institut für Kernphysik; Alemania Fil: Dörner, R.. Universität Freiburg; Alemania Fil: Rodríguez Chariarse, Vladimir Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Mergel, V.. Institut für Kernphysik; Alemania Fil: Jagutzk, O.. Institut für Kernphysik; Alemania Fil: Schmidt, L.. Institut für Kernphysik,; Alemania Fil: Müller, K. A.. Institut für Kernphysik; Alemania Fil: Afaneh, F.. Institut für Kernphysik; Alemania Fil: Gonzalez, A.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Schmidt-Böcking, H.. Institut für Kernphysik; Alemania

We have measured the momentum distributions of singly and doubly charged helium ions created in the focus of 220 fs, 800 nm laser pulses at intensities of $(2.9--6.6)\ifmmode\times\else\texttimes\fi{}{10}^{14}\mathrm{W}/{\mathrm{cm}}^{2}$. All ions are emitted strongly aligned along the direction of polarization of the light. We find the typical momenta of the ${\mathrm{He}}^{2+}$ ions to be 5--10 times larger than those of the ${\mathrm{He}}^{1+}$ ions and a two peak structure at the highest intensity.

The dissociative electron transfer from He into 10 keV H+2 was measured in a kinematically complete experiment. For electron transfer into the dissociative b3?+u state of H2 we find a striking double slit interference pattern in the transverse momentum transfer which we can modify by selecting different internuclear distances of the hydrogen molecule. Compared to an optical double slit, interference minima and maxima are interchanged.