Efficient Water Softening for Avoidance of Scales in Heavy Oil Steam Floods

Pigging of Once Through Steam Generators (OTSGs) indicated various types of scales, the most predominant of these being silicates of hardness causing ions. It was noted that scaling propensity can potentially go up with higher Steam Quality (SQ) as the reject stream gets concentrated with ions. However, models suggested that there are benefits of higher SQ in enhancing fuel savings (8%) and electricity savings (2%) when SQ was increased by 20%. The challenges of higher SQ were noted in terms of increased scaling tendency and therefore the need for improved softening. In Field D, the service cycle, the backwash cycle, and the brining cycle were optimized leading to a gain in throughput and reduction in salt consumption. Service cycle improvement gained 30 % to 130 % in throughput between two regenerations, backwash cycle improvement by fluidizing the bed to nearly 35% helped gain 10% in throughput, and reduction of brining cycle from 75 minutes to 48 minutes helped reduce salt consumption by 56% without impacting the throughput. In Field B, a six month pilot revealed that shallow shell resins where ion-exchange is more efficient due to inert core (better intra particle diffusion control) can enhance the throughput by 30% - 80% and simultaneously reduce the number of regenerations by 15 – 30%. Resin fouling is still a major challenge to contend with as oil can foul the resin and throughput can decline by 0.5 – 3 folds. In a plant operation, where there are multiple softener and brine vessels, there is a need to optimize them as a system. Reliability, Availability, and Maintainability (RAM) Models are used in Field C to a) Address equipment configuration optimization with impact on capital capacity expansion project scope b) Understand how net softwater delivery capacity was affected by increases in inlet hardness and c) Assess through a comparison scenario, if the large cost of addressing the valve issue in an upstream nutshell filter was worth the lost production opportunity related to unplanned downtime.

Statistical Fluctuations of Energy Spectra in the Isobar A = 68 Nuclei

Statistical fluctuations of nuclear energy spectra for the isobar A = 68 were examined by means of the random matrix theory together with the nuclear shell model. The isobar A = 68 nuclei are suggested to consist of an inert core of 56Ni with 12 nucleons in f5p-space (2p3/2, 1f5/2 and 2p1/2 orbitals). The nuclear excitation energies, required by this work, were obtained through performing f5p-shell model calculations using the isospin formalism f5pvh interaction with realistic single particle energies. All calculations of the present study were conducted using the OXBASH code. The calculated level densities were found to have a Gaussian shape. The distributions of level spacing P(s) and statistic for the considered classes of states, obtained with full Hamiltonian of f5pvh (absence of the off-diagonal Hamiltonian) calculations, showed a chaotic (regular) behavior and coincided well with the distribution of Gaussian orthogonal ensemble (Poisson). Moreover, these distributions were independent of spin (J) and isospin (T)

Thermo-enhanced Upconversion Luminescence in Inert-core/Active-shell UCNPs: Inert-core Matters

Recent discoveries on the anomalous thermo-enhanced luminescence of upconversion nanoparticles (UCNPs) have attracted great interests because of their potential significant technological importance. Meanwhile, equally compelling may be the great debate...

Shell model calculations in the A ~ 100 mass region

The properties of nuclei with 39≤Ζ≤47 and Ν=51-52 are investigated in large scale shell-model calculations. The doubly closed nucleus 100Sn is selected as the reference state and the nuclei under examination are described in terms of proton holes and one up two neutrons outside the inert core. The proton holes are distributed in a model space consisting of the orbitals g9/2, p1/2, p3/2 while f5/2 is sometimes also considerd. Similary the model space for the neutron particles in­ cludes the orbitals g7/2, d5/2, d3/2, s1/2 and in certain cases h11/2. The effective two-body interaction and the matrix elements of the effective operators were deter­ mined by introducing second-order corrections to the Sussex matrix elements. The single proton holes as well as the single-neutron energies were treated as parameters which were determined by least-squares fit to the observed levels of 39≤Ζ≤47, Ν=50 and Ν=51 respectively. The results of the calculation were found to be in satisfactory agreement with experimental data and this enable us to make predictions about the properties of some exotic nuclei in the vicinity of 100Sn.

Shell model calculations in the A=90-98 mass region. A study of the N=51. nuclei

The properties of nuclei with 39 < Ζ < 47 and N=51 are investigated in large scale shell-model calculations. The doubly closed nucleus 100Sn is selected as the reference state and the nuclei under examination are described in terms of proton holes and a single neutron outside the inert core. The proton holes are distributed in a model space consisting of the orbitals g9/2, p1/2, p3/2 while f5/2 is sometimes also considerd. Similary the model space for the single neutron includes the orbitals g7/2, d5/2, d3/2, s1/2 and in certain cases h11/2. The effective two-body interaction and the matrix elements of the effective operators were determined by introducing second-order correctios to the Sussex matrix elements. The single proton holes as well as the single-neutron energies were treated as parameters which were determined by least-squares fit to the observed levels of 39 < Ζ < 47, N=50 and Ν=51 respectively. The results of the calculation were found to be in satisfactory agreement with experimental data and this enable us to make predictions about the properties of some exotic nuclei in the vicinity of 100Sn.

Concerning the Li-rich status of KIC 9821622: a Kepler field RGB star reported as a Li-rich giant

ABSTRACT Given the implications for the origin of Li enhancement in red giants, we have reviewed the Li-rich classification of KIC 9821622, the only bonafide red giant branch (RGB) giant with a He inert core to date, reported as a Li-rich giant by reanalysing the high-resolution spectra. We have obtained A(Li)LTE = 1.42 ± 0.05 dex. After correcting for non-local thermodynamic equilibrium (NLTE), we have A(Li)NLTE = 1.57 ± 0.05 dex, which is significantly less than the reported A(Li) = 1.80 ± 0.2 dex. We found that the subordinate line at 6103 Å is too weak or absent to measure Li abundance. The derived abundance is normal for red giants undergoing dilution during the first dredge-up. Since all known Kepler field Li-rich giants belong to the red clump region, this clarification removes the anomaly and strengthens the evidence that Li enhancement in low-mass giants may be associated only with the He-core burning phase. The origin of Li excess probably lies during the He flash at the RGB tip, a phase immediately preceding the red clump.

Nuclear energy levels in 58Ni

Energy levels, total angular momenta and parity for two nucleons that present outside closed core 56Ni (Nickel) which occupied FP nuclear shell have been calculated using nuclear shell model application. We have used FP M3YE interaction to calculate energy levels of 58Ni, in addition, the results are compared with experimental data, modified surface delta interaction (MSDI), Reid's potential (RP) and non-zero pairing shell model (NZPSM). Harmonic Oscillator potential is used to generate single particle wave functions in FP shell and considering as an inert core. Oxford Buenos Aires Shell Model (OXBASH) code for nuclear shell model calculation has been utilized to carry out the calculations and comparison with experimental data had been done. http://dx.doi.org/10.25130/tjps.24.2019.054

Inelastic longitudinal electron scattering C42 form factors in42Ti nucleus

Inelastic longitudinal electron scattering form factors for secondexcited state C42 in 42Ti nucleus have been calculated using shellmodel theory. Fp shell model space with configuration (1f7/2 2p3/21f5/2 2p1/2) has been adopted in order to distribute the valenceparticles (protons and neutrons) outside an inert core 40Ca. Modernmodel space effective interactions like FPD6 and GXPF1 have beenused to generate model space vectors and harmonic oscillator wavefunction as a single particle wave function. Discarder space (coreorbits + higher orbits) has been included in (core polarization effect)as a first order correction in microscopic theory to measure theinterested multipole form factors via the model space.Gogny and Michigan sum of three-range Yukawapotential (M3Y-p2) have been utilized as a residual interaction tocouple the (particle-hole) pair across the model space active particlesand the excitation energy of the pair is (2ħω) and four options for theused effective and residual interactions were determined for thetransitions from (+0) to (+01,2,3), (+21,2,3) and (+41,2,3).

Inelastic transverse magnetic dipole electron scattering form factors in 48Ca (restricted optimum configurations)

Inelastic transverse magnetic dipole electron scattering formfactors in 48Ca have been investigated through nuclear shell modelin an excited state energy Ex= 10.23 MeV which is so called"mystery case" with different optional choices like effectiveinteraction, restricted occupation and core polarization interaction.40Ca as an inert core will be adopted and four orbits with eightparticles distributed mainly in 2p1f model space and in some extendrestricted to make sure about the major accuse about this type oftransition. Theoretical results have been constituted mainly withexperimental data and compared with some important theoreticalresults of the same transition.