Absorption Quantities Research Articles

Energy absorption characteristics of novel bionic H-type whip restraints for nuclear power plants

To enhance the efficiency of energy absorption in H-type whip restraints for nuclear power plants, this study takes inspiration from the asymmetric twisted lines observed in the Nautilus shell, introducing the Nautilus Bionic Hierarchical Multi-Cell (NBHMC) structure. For different high-energy pipeline sizes and energy absorption quantities, the proposed structures are miniaturized and can be combined into H-type whip restraint by multiple tubes to meet the requirements. The NBHMC structures are investigated based on the validated finite element method, the results demonstrate that the energy absorption per unit mass of the new structure can reach up to 180% of that of the hollow tube, with the maximum enhancement in energy absorption efficiency being 47%. Through parameter analysis of the cross-sectional wall thickness, the highest energy absorption efficiency obtained is 99.62%, with a specific energy absorption of 31.29J/g. Furthermore, utilizing the TOPSIS method, all proposed parameter combinations are ranked, leading to the determination of the optimal parameter combination. Additionally, a theoretical model predicting the mean crushing force is introduced, exhibiting good agreement with numerical simulations. The results presented in this work provide innovative insights for the design of efficient pipe whip restraints.

Synthesis, Characterization, and Ecotoxicology Assessment of Zinc Oxide Nanoparticles by In Vivo Models

The widespread use of zinc oxide nanoparticles (ZnO NPs) in multiple applications has increased the importance of safety considerations. ZnO NPs were synthesized, characterized, and evaluated for toxicity in Artemia salina and zebrafish (Danio rerio). NPs were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV-Vis) spectroscopy. The hydrodynamic size and stability of the ZnO NP surface were examined using a Zetasizer. Characterization techniques confirmed the ZnO wurtzite structure with a particle size of 32.2 ± 5.2 nm. Synthesized ZnO NPs were evaluated for acute toxicity in Artemia salina using the Probit and Reed and Muench methods to assess for lethal concentration at 50% (LC50). The LC50 was 86.95 ± 0.21 μg/mL in Artemia salina. Physical malformations were observed after 96 h at 50 μg/mL of exposure. The total protein and cytochrome P450 contents were determined. Further analysis was performed to assess the bioaccumulation capacity of zebrafish (Danio rerio) using ICP-OES. ZnO NP content in adult zebrafish was greater in the gastrointestinal tract than in the other tissues under study. The present analysis of ZnO NPs supports the use of Artemia salina and adult zebrafish as relevant models for assessing toxicity and bioaccumulation while considering absorption quantities.

Robust half-metallic ferromagnet in doped double perovskite Sr2TiCoO6 by rare-earth elements for photovoltaic and thermoelectric conversion: A DFT method

In this study, we have discovered a novel candidate series of half-metals by replacement of the Ti atom with the rare-earth elements RE (=Dy, Ho, Er, or Tm) in the double perovskite Sr2TiCoO6. We methodically investigated the electronic, magneto-optical, and thermoelectric characteristics of the compounds Sr2(RE)CoO6 using the FP-LAPW method. The spin-polarized electronic structure studied within GGA-WC and GGA + U showed a robust half-metallic character for all compounds. The substitution by the rare-earth elements RE enhanced the magnetic characteristics of Sr2TiCoO6, which exhibits a transition from a total magnetic moment of 1μB for Sr2TiCoO6 to 7μB, 6μB, 5μB, and 4μB for Sr2DyCoO6, Sr2HoCoO6, Sr2ErCoO6, and Sr2TmCoO6, respectively. However, the hybridization between RE-4f, Co-3d, and O-2p is responsible for robust half-metallic ferromagnet in Sr2(RE)CoO6 compounds. We have also studied the effect of spin-orbit coupling (SOC) on electronic structure. The Sr2DyCoO6, Sr2HoCoO6, and Sr2ErCoO6 compounds maintained their half-metallicity under GGA + SOC, whereas Sr2TmCoO6 became a magnetic metal. An in-depth analysis of the optical and thermoelectric characteristics was performed by GGA + U. According to the absorption coefficient and imaginary part of the dielectric function, we have found that the compounds Sr2(RE)CoO6 have better absorption quantities at different frequencies (IR, visible, and UV) than Sr2TiCoO6. Due to their high ZT and good Seebeck coefficient in a spin-up canal, the investigated compounds have excellent thermoelectric efficiency. These characteristics make the double perovskites Sr2(RE)CoO6 as a high absorber an attractive choice for photovoltaic solar cells and thermoelectric applications.

Optical properties and radiation shielding performance of tellurite glassy composites: Role of rare earth oxides

In this research, the synthesis, optical parameters, and radiation absorption quantities of 50TeO2–15Na2O—(20-x)PbO—15ZnO—xEu2O3 glasses were reported. The glasses were prepared by the well-known melting and quenching method using high purity chemicals. The glasses were coded as TPEu-0, TPEu-1, TPEu-2, and TPEu-3 for glasses containing 0, 1, 2, and 3 mol% of Eu2O3, respectively. The density of the glasses was determined by the Archimedes method. The optical parameters of the glasses, such as the refractive index n, molar refractivity Rm, molar polarizability αm, reflection loss RL, optical transmission T, metallization criterion M, static dielectric constant εstatic, and optical dielectric constant εoptical were estimated by theoretical methods. The stopping powers and range of electrons, protons, α-particles, and carbon ions in the TPEu-X glasses for particle kinetic energies between 15 keV and 15 MeV were computed using the ESTAR, PSTAR, ASTAR, and STRIM software. In addition, the fast neutron (FN) removal cross section (FNRCS), thermal neutron (TN), and total cross-section (σtot) for the prepared glasses were evaluated theoretically using established models. The estimated optical parameters showed strong relationship with the chemical content of the glasses. Glass density and molar volume increased as Eu2O3 content increased. The Rm, αm, RL, εstatic, and εoptical vary from 16.24 to 17.20 cm3/mol, 6.44 × 10−24 cm3‒17.20 × 10−24 cm3, 0.17–0.19, 5.71–6.55, and 4.71–5.55 respectively, with TPEu-0 and TPEu-1 having the maximum and minimum values, respectively. Generally, the increase in Eu2O3 concentration increased the charged radiation shielding ability of the glasses. The increment in the Eu2O3 content of the glasses brought about an improvement in the thermal and fast neutron absorption probabilities of the glasses.

Optical transmission quality and radiation protection relevance of TeO2-ZnO-Yb2O3-ZnCl glass system

Tellurite glasses are known to present attributes which makes them attractive for optical and radiation shielding functions. This study presents the optical and γ-radiation absorption quantities of (89-x)TeO2 -xZnCl-10ZnO-Yb2O3 (for 0 ≤ x ≤ 30 mol. % in steps of 10 mol. % and coded as TZZCY1-TZZCY4 accordingly). The optical characteristics of the glasses were determined through the estimation and analysis of optical quantities such as the molar volume, molar refractivity, molar polarizability, reflection-loss, optical-transmission, metallization-criterion, static dielectric constant and the optical dielectric constant. The mass attenuation coefficient MAC of the glasses was estimated for energy E in the range 0.015≤E≤15 MeV through XCOM computation and photon transmission simulation by PHITS. The gamma ray shielding competence of the glasses was analysed through the computed mass attenuation coefficient, the linear attenuation coefficient, effective atomic number, mean free path, and half-value layer HVL. The molar refractivity, molar polarizability, reflection loss, static dielectric constant, and optical dielectric constant, all decline with increase in ZnCl2 content of the glasses while the optical transmission and metallization criterion increases. The addition and increase in the proportion of ZnCl2 compromised the photon-absorption ability of the TZZCY glasses although the optical transparency of the glasses was improved.

Gamma shielding performance of the optical B2O3-based glass system

The gamma shielding and dosimetric quantities of the optical (55-x)B2O3 − 20CaF2- 5GeO2- 20Bi2O3-xCuO glass system are reported here. We studied different concentrations of CuO content, that is, 0 (BCGBC1), 1 (BCGBC2), 3 (BCGBC3), and 5 (BCGBC4) mol%. The mass attenuation coefficient of the glass system was estimated for 15 – 15,000 keV photons through the use of XCOM. Other photon shielding and dosimetric quantities such as mass energy absorption coefficient μen, specific gamma ray constant Γ, equivalent atomic number Zeq, effective atomic number Zeff, effective electron density Neff, gamma dose rate Dr and gamma photon buildup factors (exposure (EBF) and energy absorption (EABF) are estimated using standard deterministic expressions. Analysis of other related photon absorption quantities shows that there is a thin line between the gamma shielding ability of the glasses especially at energies beyond 0.1 MeV. In addition, the increase in the CuO content of the glasses slightly decreased the photon buildup within the glasses. The potential of the glasses to function well in radiation protective relation applications was demonstrated by the higher mass attenuation coefficient of BCGBC4 glass compared to different commercial shielding glasses, concrete samples, and other categories of materials with high shielding functionality.

Synthesis and analysis of flakes graphene oxide

The presented article is devoted to the synthesis and analysis of flakes graphene oxide obtained by the Hammers method. The synthesized flakes graphene oxide was studied using SEM, EDX, X-ray diffraction, Raman spectroscopy, element analysis, temperature dependent of resistance and IR spectroscopy. As a result of calculating the results of X-ray analysis according to the Debye-Scherer’s formula, the thickness of graphite flakes was about 12,9nm and the number of layers was 38. The result of the Raman analysis show that high quality flakes grapheme oxide was obtained. Based on the result of elementary analysis of grapheme oxide mass, the C/O ratio was determined to be 1,42. The grapheme layers inside the sample were 3,31nm thick and 14,8nm long by scanning electron microscope. The temperature variation of the resistance was determined. IR spectroscopy shows the results of the absorption of electromagnetic radiation in the infrared range by atomic groups of reduced grapheme oxide and the excitation of the molecule by light quanta. When a molecule is irradiated with infrared radiation, it is shown that only quantum absorption quantities are formed according to the frequencies of the molecules.

Mechanical, optical, and gamma-attenuation properties of a newly developed tellurite glass system

ObjectiveThis study presents an experimental evaluation of the optical properties of a newly developed 75TeO2-5Na2O-(20-x)BaO-xTiO2 (with x = 0; 5; 10; 15) glass system. Moreover, we examine the mechanical and gamma attenuation features of the studied glasses. MethodThe glasses were prepared by the melt and rapid quench method; gamma attenuation coefficients were obtained through FLUKA simulations and XCOM computations; UV-Vis data were used to estimate the optical parameters of the glasses; while the mechanical quantities were estimated theoretically. ResultsThe optical, mechanical, and gamma radiation absorption quantities showed fluctuations as the chemical composition of the glasses changed. The refractive index changes from 2.35 to 2.43 while the optical bandgap and transmission declines from 3.20 eV and 72% to 2.88 eV and 70% respectively as the molar concentration of TiO2 changes from 0−15 mol%. The computed Young’s, bulk, shear, and longitudinal modulus increased from 210.31 to 256.53, 126 – 158.92, 91.90 – 111.33, and 249.11 – 307.35 GPa respectively for increasing TiO2 content. The calculated gamma radiation shielding parameters shielding effectiveness of the glasses narrowly trend in the order of TNB-Ti00 > TNB-Ti05 > TNB-Ti10 > TNB-Ti15. ConclusionCompared to conventional glass shields and shielding concrete, the present glasses are superior. The optical, mechanical, and shielding qualities of the investigated glass system reveal their huge potentials in optical and structural shielding applications in radiation facilities.

Influence of iron (III) oxide on the optical, mechanical, physical, and radiation shielding properties of sodium-barium-vanadate glass system

The physical, optical, mechanical, and radiation absorption features of a Sodium-barium-vanadate glass system containing iron (III) oxide were obtained by direct calculations and Monte Carlo simulations in this study. The investigated glasses have a chemical definition given as (20 – x)Na2O + 25BaO + 55V2O5 + xFe2O3 (where x = 0, 5 10, 20 mol% represents SBV-Fe0–3). The mass density from 3.732 to 4.326 g cm−3 while molar volume decreased from 40.40 to 39.37 cm3 mol−1 as the Fe2O3 insertion ratio rose in the glasses. Replacing Na2O with Fe2O3 in the glasses led to a decrease in the refraction index, reflectance loss, and metalization criterion of the glasses, while on the other hand the optical transmittance increased. The Young's, longitudinal, bulk, and shear moduli all increased as the glass density improved. The gamma radiation shielding competence evaluated from FLUKA simulations and confirmed by XCOM calculations revealed that the incident photon energy and the chemical structure of the glasses influenced the photon absorbing capacity of the glasses. The linear attenuation coefficient decayed from 0.4852 to 0.1409 cm−1 for SBV-Fe0 while that of SBV-Fe1, SBV-Fe2, and SBV-Fe3 decayed from 0.5021 to 0.1479 cm−1, 0.5203 to 0.1544 cm−1, and 0.5573 to 0.1656 cm−1 accordingly as energy increases from 0.284 to 2.506 MeV. Similarly, the mass attenuation coefficient, effective atomic number and other estimated photon absorption quantities all point to an improved absorption capacity with the trend SBV-Fe0 < SBV-Fe1 < SBV-Fe2 < SBV-Fe3. Further, the ΣR of the glasses have values of 1.2162, 1.1977, 1.1919, and 1.213 cm−1 for the SBV-Fe0–3 respectively. Analysis of the thermal neutron cross section of the glasses reveals that the inclusion and subsequent increase of the Fe2O3 content of the SBV-Fe glasses has a positive impact on the thermal neutron interaction parameters. SBV-Fe glasses are valuable materials for radiation absorption functions when compared with common shields.

Adsorption and absorption of supercritical methane within shale kerogen slit

Gas storage in shale primarily includes three forms: free gas in the fractures or macropores, adsorbed gas upon the kerogen surface, and absorbed gas in the kerogen matrix. However, current techniques cannot distinguish the adsorbed and absorbed gas, which restrict the understanding of gas storage and transport mechanisms through shale kerogen. On the basis of the grand canonical Monte Carlo (GCMC) simulations, we propose a technique to determine the independent adsorption and absorption isotherms of methane within slit-shaped shale kerogen under supercritical conditions. We observe that if the pore pressure is higher than ~3.5 MPa, the absorption amount is much smaller than that of adsorbed gas; however, at lower pressures, the absorption capacity is superior to that of the adsorption. Meanwhile, the ratio between adsorption and absorption quantities continuously increases with pressure. We probe the underlying mechanisms and study the effect of slit aperture, temperature, as well as moisture on gas adsorption and absorption capacity. Enlarging the slit aperture increases the adsorbed gas contents but shows only a negligible effect on the absorption capacity. Heating facilitates the escapement of gas molecules, thus leading to the inhibition of both adsorption and absorption capacities. Water molecules occupying the adsorption site on the slit surface impedes methane adsorption, but the absorption capacity within the kerogen matrix remains unchanged. This work elucidates the gas adsorption and absorption behavior in shale kerogen and sheds light on the storage and transport of hydrocarbons in nanoporous materials.

Many-body perturbation theory calculations using the yambo code

yambo is an open source project aimed at studying excited state properties of condensed matter systems from first principles using many-body methods. As input, yambo requires ground state electronic structure data as computed by density functional theory codes such as Quantum ESPRESSO and Abinit. yambo’s capabilities include the calculation of linear response quantities (both independent-particle and including electron–hole interactions), quasi-particle corrections based on the GW formalism, optical absorption, and other spectroscopic quantities. Here we describe recent developments ranging from the inclusion of important but oft-neglected physical effects such as electron–phonon interactions to the implementation of a real-time propagation scheme for simulating linear and non-linear optical properties. Improvements to numerical algorithms and the user interface are outlined. Particular emphasis is given to the new and efficient parallel structure that makes it possible to exploit modern high performance computing architectures. Finally, we demonstrate the possibility to automate workflows by interfacing with the yambopy and AiiDA software tools.

Experimental Research on Bleeding Performance of Single Well Ground-water Heat Pump

Groundwater bleeding is one of the most significant factors in the development of single well groundwater heat pump (SWGWHP), which can be used to improve thermal well performance for a better operation condition. Therefore, a series of tests for bleeding feature have been carried out by a sandbox experimental table, including designing bleeding rate from 0 to 30% in standing column well (SCW) and forced external circulation standing column well (FECSCW). The results of experimental research show that in the heating mode bleeding can improve the outlet water temperature (OWT) and heat absorption quantities (HAQ) of the thermal well, especially the effect on improving the OWT of SCW. However, the role of higher bleeding rate is limited. With the bleeding rate increasing from 5% to 32.1%, the HAQ of FECSCW increases only 7.4%. Moreover, groundwater bleeding reduces the heat influence scope (HIS) of the thermal well.

Numerical Simulation of Forced External Circulation Standing Column Well Based on CFD

In view of the deficiency of numerical simulation research on the underground heat transfer system of the forced external circulation standing column well (FECSCW), based on the existing FECSCW sandbox experimental table, two multi-zone coupled 3D CFD models in different sizes were established. The models were validated by outlet water temperature (OWT) and accumulative heat absorption quantities (AHAQ) of thermal well. The experimental value of OWT agrees well with the simulation value. The relative error of AHAQ in 25 min is 3.28% and 5.56% respectively. The simulation results show that the size of the sandbox will affect the aquifer flow/temperature field. Sandbox size increases from 1.5×1.5×1.0 m3 to 2×2×1.58 m3, while the aquifer streamlines deform from "elliptical" into "butterfly", and the temperature field of top plate of sandbox is unaffected. The backfill gravel zone will induce the flow transfixion, while the width of the seal zone (WSZ) and the distances between pumping and injection screens (DPIS) will affect the rate of inlet water entering the pumping screen. Therefore, in order to avoid the influence of inlet water on boundary conditions. Actual engineering and sandbox experiment should increase the distance between injection screen and upper roof of aquifer, and the distance between thermal well and the walls. Moreover, the WSZ and the DPIS should be especially considered, in order to reduce the flow/thermal transfixion.

Molecularly imprinted polymeric microspheres with metalloporphyrin-based molecular recognition sites coassembled with methacrylic acid

Molecularly imprinted polymeric microspheres (MIPMs) for dimethyl methylphosphonate (DMMP) were prepared using methacrylic acid (MAA) and vinyl-substituted zinc(ii) porphyrin as functional monomers. The interactions of vinyl-substituted zinc(ii) porphyrin with DMMP were determined by ultraviolet–visible absorption spectroscopy. A comparison between the MIPMs-MAA that used only MAA with the MIPMs-zinc (Zn) + MAA that used both MAA and Zn porphyrin as functional monomers revealed that the MIPMs-Zn + MAA showed higher binding ability for DMMP. By the Scatchard analysis, the results of the equilibrium adsorption test showed that the MIPM-DMMP only had one affinity binding site. The dissociation constants of MIPMs-Zn + MAA and MIPMs-MAA were 0.167 and 0.338 mmol/L, respectively, and the maximum absorption quantities were 148 and 13.57 μmol/g, respectively. The MIPMs-Zn + MAA possessed the higher selectivity for DMMP as shown by the isotherm binding test. These results revealed that the MIPMs-Zn + MAA had highly specific binding sites because they were assembled by the two functional monomers, vinyl-substituted Zn(ii) porphyrin and MAA, which coordinated to achieve specific binding with DMMP.

X-RAY PROPERTIES OF THE NORTHERN GALACTIC CAP SOURCES IN THE 58 MONTHSWIFT/BAT CATALOG

We present a detailed X-ray spectral analysis of a complete sample of hard X-ray selected AGN in the Northern Galactic Cap of the 58-month Swift Burst Alert Telescope (Swift/BAT) catalog, consisting of 100 AGN with b>50deg. This region has excellent potential for further study due to the availability of a wide range of archival multi-wavelength data, and we propose it as a low-redshift analog to the `deep fields' work on AGN at higher redshifts. We present distributions of luminosity, absorption, and other key quantities, from fitting new and archival X-ray data gathered from XMM-Newton, Swift/XRT, ASCA and Swift/BAT. We probe to deeper redshifts than the 9-month BAT catalog (<z>=0.043), and uncover a broader absorbing column density distribution. The fraction of obscured (log N_H >= 22) objects in the sample is ~60%, and 43--56% of the sample exhibits `complex' 0.4--10keV spectra. The soft excess is either well-detected in AGN or undetected, suggesting that the process responsible for producing the soft excess is not ubiquitous. The fraction of Compton-thick sources in our sample is ~9%, and `hidden/buried AGN' constitute ~14% of our sample. Compton reflection is found to be important in a large fraction of our sample using joint XMM-Newton+BAT fits (reflection amplitude <R> = 2.7 +/- 0.75), indicating light bending or extremely complex absorption. The average 1--10keV spectrum for the sample reproduces the 1--10keV X-ray background slope as found for the 9-month BAT AGN sample. The completeness limit for the sample is ~4 times fainter than that for the 9-month catalog (abridged).

Competition Absorption and Desorption Dynamic Character of Cadmium, Lead and Zinc by Soil in North-East of China

The competitive absorption and desorption of cadmium (Cd), lead (Pb) and zinc (Zn) in meadow brown soil from Liaoning province in north-east China was studied in the paper in order to establish the selectivity sequences for the sorption and desorption of these heavy metals in the soil and obtain the absorption and desorption dynamic character of these heavy metals. The results showed that with the increasing of the absorption times, the absorption quantities of Cd, Pb and Zn were increased little by little. The absorption process of Cd, Pb and Zn could be divided into the fast absorption phase and the slow absorption phase. And the fast absorption phases were from the beginning to 60 min, 120 min and 120 min for Cd, Pb and Zn, respectively. The more company metals (i.e. Pb and Zn) existed in the absorption solutions, the less absorption quantities of Cd absorbed by soil. The co-existence of Cd, Pb and Zn had obviously decreased the absorption of Pb by soil. And it was the same situation that Zn absorbed by soil was decreased by the company metals such as Cd, Pb. The company metals had obvious influence on the desorption process of Cd. The existence of Pb and Zn promoted the desorption of Cd. And desorption behavior of Zn was bated by the existence of Pb and Cd. While the company metals Cd and Zn restrained the desorption of Pb. The best equation to describe the absorption and desorption dynamic character of Cd, Pb and Zn was Elovich equation, next was Two–constant equation, and the effect of First-order dynamics equation was not good.

A study on an axial crush configuration response of thin-wall, steel box components: The quasi-static experiments

An experimental investigation was performed to study a specific axial crush configuration response of steel, square box components under quasi-static testing conditions. For a specific cross-sectional geometry/fabrication process, test specimens were obtained from commercially produced, welded tube lengths of ASTM A36 and ASTM A513 Type 1 plain low-carbon steels and AISI 316 and AISI 304 austenitic stainless steels. Removable grooved caps were used to constrain tube test specimen ends, and collapse initiators in the form of shallow machined grooves were used to control the initial transverse deformations of the test specimen sidewalls. The progressive plastic deformation for all of the test specimens was restricted to the prototype configuration response (fold formation process and the corresponding axial load-axial displacement curve shape) of the symmetric axial crush mode. Crush characteristics were evaluated and, for each material type, observed differences were less than 7% for maximum and minimum load magnitudes and less than 2% for energy absorption, displacement, and mean load quantities in both the initial phase and the secondary folding phase cycles. Overall, results of the study indicate that for a significant range of material strengths, a controlled and repeatable energy absorption process can be obtained for commercially produced steel box components undergoing symmetric axial crush response.

Local properties of the potential-energy landscape of a model glass: Understanding the low-temperature anomalies

Though the existence of two-level systems (TLS) is widely accepted to explain low temperature anomalies in the sound absorption, heat capacity, thermal conductivity and other quantities, an exact description of their microscopic nature is still lacking. We performed computer simulations for a binary Lennard-Jones system, using a newly developed algorithm to locate double-well potentials (DWP) and thus two-level systems on a systematic basis. We show that the intrinsic limitations of computer simulations like finite time and finite size problems do not hamper this analysis. We discuss how the DWP are embedded in the total potential energy landscape. It turns out that most DWP are connected to the dynamics of the smaller particles and that these DWP are rather localized. However, DWP related to the larger particles are more collective.

Study and Evaluation of Aging Performance of Petroleum Asphalts and Their Constituents During Oxygen Absorption. I. Oxygen Absorption Behaviors and Kinetics

The oxygen absorption behaviors and kinetics of Shanjiasi, Shengli, and Renqiu petroleum asphalts and their constituents including saturates, aromatics, resins, and asphaltenes were successfully studied at 50°C, 0.133 MPa (O2) and 1 mm sample film in darkness by means of precise measurement of oxygen pressure changes in reactor. The experimental results that the resin and the asphaltene can easily absorb oxygen and they are more active constituents in petroleum asphalt, while the saturate hardly absorbs oxygen, which is the most stable constituent of petroleum asphalt. The better the antiaging performance of straight run petroleum asphalt, the more stable its constituents and the less oxygen they absorb generally. The oxygen absorption rate of asphaltene diluted with the lower viscous saturate is obviously higher than that of pure asphaltene. The resin constituent of Shanjiasi asphalt could remarkably improve the antiaging ability of Shengli asphalt by the constituent substitution. The kinetic model of maximum combined oxygen presented in this paper could satisfactorily explain the oxygen absorption behaviors of petroleum asphalts and their constituents, and the oxygen absorption quantities calculated by the model are very identified with the test ones.

STUDY OF DIESEL FUEL STABILITY ON OXYGEN ABSORPTION. II. EFFECT OF TEMPERATURE AND OXYGEN PRESSURE

The effect of temperature and oxygen pressure on oxygen absorption properties of Daqing straight run diesel fuel (SRDF) and Daqing hydrogenated coking diesel fuel (HCDF) was investigated at 293 ∼ 353 K under 0.11 ∼ 0.25MPa(O2) and Cu catalysis in darkness based on the study of diesel fuel stability on oxygen absorption. The experimental results show that the oxygen absorption quantities (OAQs) of diesel fuels increase rapidly with the increasing of temperature or oxygen pressure at given time and oxygen pressure or temperature during the oxygen absorption. The higher the oxygen pressure or the temperature and the longer the time, the greater the OAQ of diesel fuel. The OAQs of diesel fuels change a little at shorter times, while they vary greatly at longer times. Low temperature has a great effect on OAQ of SRDF and high temperature affects clearly OAQ of HCDF. Oxygen pressure gives a evident action on OAQ of SRDF, but it affects a little OAQ of HCDF. At low temperature or high oxygen pressure the OAQ of HCDF is less than that of SRDF, while at high temperature or low oxygen pressure the OAQ of HCDF greater than that of SRDF. The more the types of unstable constituents and the higher their contents in diesel fuel, the easier the oxygen absorption reaction takes place and the more obviously the diesel fuel stability or quality deteriorates.