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Four-dimensional Langevin equations have been applied to calculate the neutron multiplicity and evaporation residue cross section for hot nuclei. The projection of the total spin of the compound nucleus to the symmetry axis, K, is...
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Four-dimensional Langevin equations have been applied to calculate the neutron multiplicity and evaporation residue cross section for hot nuclei. The projection of the total spin of the compound nucleus to the symmetry axis, K, is the fourth dimension in Langevin dynamical calculations. The relaxation time of the K as a function of the dynamical parameters is investigated. Calculations were performed for the ~(18)O+~(192)Os and ~(19)F+ ~(169)Tm reactions with a non-constant dissipation coefficient for the K coordinate. The obtained results based on four-dimensional Langevin equations with a non-constant dissipation coefficient in comparison with calculations based on a constant dissipation coefficient (γ_K = 0.077(MeVzs)~(-1/2)) are in better agreement with the experimental data. The difference between the two models for the evaporation residue cross section is high, whereas for neutron multiplicity, the discrepancy is low.
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We have systematically studied the interaction of ultrapure, de-ionized water droplets with chemically amplified, deep-ultraviolet photoresist layers during evaporation by means of experiments. The contact lines of the evaporating...
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We have systematically studied the interaction of ultrapure, de-ionized water droplets with chemically amplified, deep-ultraviolet photoresist layers during evaporation by means of experiments. The contact lines of the evaporating droplets undergo two pinning events. The footprint diameters during pinning D-1,D-2 scale with the initial droplet diameter D-0 approximately as D-1,D-2 similar to D-0(4/3). Evaporated droplets leave a residue behind, generally in the form of an ultrathin layer (order 1-10 nm) with a sub-micron thick mound in the center. We have systematically characterized the residue dimensions as a function of the initial droplet size, the photoresist composition and process conditions. Post-evaporation rinsing steps were found to be unable to completely remove a deposit, depending on how long after droplet evaporation they were performed. Our results indicate that the occurrence of so-called watermark defects might be related to deliquescence induced by ionic residues.
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The PMS (Particle Measuring Systems, Boulder, Colorado) nonvolatile residue monitor (NVR monitor) has been used to measure residues in isopropyl alcohol, tap water, and solutions prepared by dissolving different salts in deionized...
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The PMS (Particle Measuring Systems, Boulder, Colorado) nonvolatile residue monitor (NVR monitor) has been used to measure residues in isopropyl alcohol, tap water, and solutions prepared by dissolving different salts in deionized (DI) water. The instrument was operated in the batch and on-line modes mostly with the heater on. The manufacturer's calibration was confirmed with KCl solutions of different concentrations. The results show that the instrument responded linearly to the concentration change of solutes in DI water and had excellent repeatability. However, the instrument's response depends strongly on the solutes.
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Detection of fission and spallation-evaporation residues resulting from interaction of relativistic protons with uranium, lead and gold targets in mica track detectors is investigated by the Monte Carlo method and using experiment...
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Detection of fission and spallation-evaporation residues resulting from interaction of relativistic protons with uranium, lead and gold targets in mica track detectors is investigated by the Monte Carlo method and using experimental data available in literature. It is shown that the contribution of spallation-evaporation residues to total track density is strongly dependent on target thickness and is the least for thick targets. This contribution in the case of thick target materials with Z≥ 79 is less than or is within the statistical uncertainty of a typical track density measurement. Although our results on registration and detection of the spallation residues in mica are based on the interactions of uranium and lead with protons at 1A CeV and gold with protons at 0.8A CeV, they are applicable to all targets with Z≥ 79 and for proton energies much higher than 1 GeV.
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The role of different Skyrme forces and associated neutron transfer effect is investigated in the view of Ca-40,Ca-48 + Zr-96 reactions. The fusion cross section has been calculated using Wong formula and extended Wong model, wher...
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The role of different Skyrme forces and associated neutron transfer effect is investigated in the view of Ca-40,Ca-48 + Zr-96 reactions. The fusion cross section has been calculated using Wong formula and extended Wong model, wherein neutron transfer effect is studied by scaling the transmission probability of contributing channel(s). The decay analysis is carried out in the framework of dynamical cluster decay model, where the neck length Delta R and corresponding barrier modification Delta V-B are used to explore the neutron transfer effect in the decaying fragments. For fusion and subsequent decay, the nuclear proximity potential is calculated using Skyrme interactions such as SIII, GSkI, SkT1, SkT2, and SkT3. In Ca-40 + Zr-96 case, the fusion hindrance is observed at sub barrier energies for the use of SIII, SkT1, SkT2 Skyrme forces. The cross sections are improved to some extent for GSkI force. Further, the inclusion of in-transfer channel in the calculations shows that the experimental data is adequately addressed for GSkI force, however, the correction of ln-transfer channel for SkT1 (or SIII, SkT2 forces), persists with the poor fit to experimental data. In the decay analysis, the interaction potentials significantly affect the structural properties of decaying fragments as is clear from the fragmentation potential and preformation probability. Both, the fusion and decay analysis consistently advocate that GSkI force comprising of extended density-dependent term is able to address the sub barrier anomalies. The neutron transfer effect is explored in view of different choices of the Skyrme forces, which shows that the forces with higher barrier lead to more neutron transfer channel effect and vice versa. (C) 2018 Elsevier B.V. All rights reserved.
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Nanofluid droplet evaporation has attracted great interest due to its applications such as in painting, coating and patterning. In most studies, either the particle size or the concentration of nanofluid is considered as a factor ...
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Nanofluid droplet evaporation has attracted great interest due to its applications such as in painting, coating and patterning. In most studies, either the particle size or the concentration of nanofluid is considered as a factor in the formation of the residue pattern. This work aims to investigate the effect of both particle size and concentration on the residue pattern. A comprehensive study was made of the residue patterns of Al_2O_3 and TiO_2 aqueous nanofluid droplets on different substrates (i.e. glass, stainless steel and Teflon). It was found that a ring-shaped pattern was formed at low concentrations and small particle sizes, while a uniform pattern was formed at high concentrations and large particle sizes for Al_2O_3 nanofluids. In addition, only ring-shaped residue patterns were observed for all concentrations of TiO_2 nanofluids. In the case of different substrates, on a material with a high contact angle with water, it was difficult to form a ring-shaped pattern. The widths of the ring-shaped pattern were analyzed as well. The results showed that the width of the ring-shaped pattern was larger for small particles. The materials of substrate and nanoparticle also influenced the width.
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The nonvolatile residue monitor (NRM) operated in the batch mode has been investigated for measuring residue after evaporation (RAE) of isopropyl alcohol (IPA) and acetone. IPA, acetone, and water were doped with known concentrati...
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The nonvolatile residue monitor (NRM) operated in the batch mode has been investigated for measuring residue after evaporation (RAE) of isopropyl alcohol (IPA) and acetone. IPA, acetone, and water were doped with known concentrations of known contaminants and then measured with the NRM to determine its calibration for these liquids. The calibrations were measured with different types of contaminants and with different drying temperatures. The NRM's calibration was identical for IPA, acetone, and water when calibrations were performed with water-soluble contaminants. Less ideal behavior was observed with water-insoluble contaminants. The NRM's performance in evaluating high purity semiconductor grade isopropyl alcohol and acetone was also investigated. RAE levels were measured in solvents purchased from four different suppliers to the semiconductor industry. The NRM was able to differentiate between the suppliers.
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In reference to recent experimental data, the evaporation residue (ER) cross sections are estimated for the Pb-203,Pb-204 systems, formed via Li-6,Li-7+Au-197 reactions, over a wide range of incident energies around the Coulomb ba...
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In reference to recent experimental data, the evaporation residue (ER) cross sections are estimated for the Pb-203,Pb-204 systems, formed via Li-6,Li-7+Au-197 reactions, over a wide range of incident energies around the Coulomb barrier, using the dynamical cluster-decay model (DCM). A comparative analysis of different isotopes of Pb formed using stable beams is carried out considering various effects, such as excitation energy, angular momentum, and deformation, etc. The role of deformation is worked out by comparing the decay path for spherical and (2) deformed fragmentations. The relative contribution of static (2i)(0) and dynamic (2i)(T) quadrupole deformations on the fragmentation path is studied. Further, the distribution of the average total kinetic energy among the binary decay fragments of Pb-203 is estimated. The role of different nuclear proximity interactions leading to a wide spectrum of barrier characteristics is also explored for better understanding of the dynamics involved. The relative contribution of the temperature dependent shell corrections is analyzed in the Li-6+Au-197 reaction. For both the systems (Pb-203,Pb-204), the calculated evaporation residue cross sections find nice agreement with the reported experimental data. Also, the contribution of the fission decay mode for the Pb-203 system is predicted over a range of incident energies. An experimental verification is called for the predicted fission cross sections and average total kinetic energy.
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The use of a fallow period to conserve rainfall as stored soil water is a long-established component of many dryland agricultural systems and there is general understanding that fallow management can play an important role in whol...
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The use of a fallow period to conserve rainfall as stored soil water is a long-established component of many dryland agricultural systems and there is general understanding that fallow management can play an important role in whole system water-use efficiency. Nevertheless there remain questions about the amount of residue required to make a difference and whether residue type or configuration matters. The magnitude of the observed effects on soil water accumulation has been variable, especially in short fallow systems. We present the results of field and lysimeter experiments of fallow management effects and extend these using simulation analyses to capture the impacts of climatic variability. The results allow identification of levels of evaporative demand and rainfall patterns that influence the effects of residue management and weed control. To move beyond whole-of-fallow, retrospective explanations of fallow management effects, we explain the results using a simple and easy to understand pulse paradigm approach adopted from the field of arid land ecology. Rainfall variability is viewed in terms of different possible sequences of rainfall events, which create pulses of soil water. By considering pulse size, frequency, duration and depth we explain the observed and simulated fallow management effects and provide a qualitative approach towards understanding and assessing soil water accumulation within the fallow period. (C) 2012 Elsevier B.V
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A meticulous study of nearly 300 fusion-evaporation cross-section data reveals that, when properly scaled, fusion excitation function complies with a universal homographic law which is, within experimental errors, reaction system ...
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A meticulous study of nearly 300 fusion-evaporation cross-section data reveals that, when properly scaled, fusion excitation function complies with a universal homographic law which is, within experimental errors, reaction system independent. From such complete and summed complete and incomplete fusion excitation functions are extracted the limiting energy for the complete fusion and the main characteristics (onset, maximum and vanishing) of the incomplete fusion. The DYWAN microscopic transport model correctly predicts the incomplete fusion crosssection for incident energies ≥ 15AMeV and suggests that the nuclear transparency is at the origin of fusion disappearance.
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