The formation of supramolecular structures forming a transition region at the oil-nanofluid interface with a low surface tension is studied as a result of a synergistic effect in the interaction of ...planar graphene nanoparticles and silicon carbide nanoparticles coated with graphene layers (Core-shell). In model experiments on a Hele-Shaw cell, it was shown that in a porous medium such hybrid nanofluids have a high displacing ability of residual oil. At the same time, the oil - nanofluid interface remains stable, without the formation of sticky fingers. In the process of research using power electron microscopy, a transition region was observed, in the structuring of which nanoparticles were directly involved. The efficiency of displacement by hybrid nanofluid depends on the concentration of nanoparticles and their interaction.
Single-phase Ce–Zr oxides with a fluorite structure were synthesized by the solvothermal method in an isopropanol medium. Synthesis was performed at the supercritical parameters of isopropanol. The ...effect of the synthesis parameters on the characteristics of the obtained materials (specific surface area, morphology, particle size, phase composition) was established. Ni (5 wt %) and Ni + Co (5 wt %) were deposited at a ratio of 1 : 1 by incipient wetness impregnation. The structure and properties of samples were characterized by physicochemical methods, such as X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and temperature-programmed reduction by hydrogen. The dependences of the conversion of reagents (CH
4
and CO
2
), the yield of hydrogen, and the Ce/Zr ratio in the Dry reforming of methane (DRM) reaction on the composition of catalysts were studied. The effect of the composition of a deposited metallic component and the Ce/Zr ratio in the support on the catalytic properties and catalysts stability in the DRM reaction was shown.
The present study reveals the patterns in the formation of the structure and properties of an EP659A-VI maraging steel in various modes of hybrid multilayer CMT technology. Panoramic macrostructural ...images of weld deposits are obtained to reveal alternating areas of large columnar and equiaxial crystals, as well as the effect of the applied CMT modes on the macrostructure of weld deposits. Regardless of the CMT process mode, the microstructure of an EP659A-VI steel in various areas of the weld deposit is represented by block martensite having a constant level of microhardness according to metallographic and durometric studies. The positive effect of layered forging during the CMT process on the total level of steel strength characteristics while retaining plasticity is established.
The copper requirements of pregnant ewes in the environment of the arid zone in the Republic of Kalmykia have been studied. The organ and tissue analyses have shown that the copper quantitative ...concentrations in the fetal tissues and organs tend to vary depending on its age. The maximum copper contents are recorded in the bone tissue and the skin (1839.7 and 1714.08 μg%, respectively) of the fetuses of 100 days of age and in the bone tissue and the liver (1843.08 and 1261.04 μg%, respectively) of the 145-day-old fetuses. In the bone tissue, the percentage of the element was relatively steady during the period of the prenatal development and varied in the range of 1839.7–1843.08 μg%. The blood copper level has slightly increased for the survey period; the blood mass increased 5.84-fold. The total amount of copper in the blood of the fetus at the age of 100 days was 111.21 μg%, while it increased up to 717.33 μg% in the blood of the 145-day-old fetus. For the period of the fetal development, the copper contents in the muscle tissue and the sheepskin with wool decreased from 957.06 to 52.53 μg% and 1714.08 to 170.7 μg%, respectively, while the total amount of this element in these tissues decreased from 3531.07 to 1020.5 μg and from 1458.65 to 1309.05 μg, respectively. The liver copper content elevated with the gestational age by 37.14 μg%, it comprised 1261.04 μg% up to the age of 145 days, and the total content increased 3.1 times. The relative percentage and the total content of copper in the lungs increased by 77.29 μg% and 4.3 times, respectively, between 100 and 145 days of age generally due to the increase in the organ masses. The total copper content in the 100-day-old and 145-day-old fetuses comprised 6.95 and 9.74 mg, respectively. The copper doses at the stages of early (55 days), middle (100 days), and late (145 days) gestation of the Kalmyk fat-rumped meat sheep were determined to be 12.93, 14.02, and 15.34 mg, respectively. Taking into consideration the fact that the dietary copper absorbtion rate is in the range of 71.05–73%, the fat-rumped ewes entering early, middle, and late pregnancy should intake 18.2, 19.3, and 21 mg dietary copper, respectively. The dietary copper intake norms per 1 kg dry matter intake are 11.0, 7.9, and 8.0 mg; the copper intake norms per 1 kg live weight should be 0.30, 0.32, and 0.35 mg.
•Lewis acid sites are responsible for valeric acid to 5-nonanone conversion on ZrO2.•Four different valerate adsorption species were identified by FTIR.•Two mechanisms of ketonization depending on ...valerate configuration were proposed.
Adsorption of valeric acid and 5-nonanone on zirconia was investigated by DRIFTS and UV–vis DRS methods. Physical adsorbed and chemisorbed acid and ketone species have been found. Based on the experimental data obtained in this work and on DFT calculations reported in the literature two β-ketoacid routes depending on surface carboxylate intermediates were proposed: (i) via interactions of surface monomolecular monodentate valerate with either monomolecular bridging bidentate or chelating bidentate and (ii) via interactions of two monodentates coordinated to the same Zr cation. The relative contribution of each of them in the overall ketone formation over metal oxide surfaces depends on the reaction conditions.
We present the first accurate results of measurements of the tensor analyzing power component
T
20
for the coherent neutral pion photoproduction on the deuteron. The measurements were performed at ...the Budker Institute of Nuclear Physics at VEPP-3 storage ring using the internal tensor polarized deuterium target. The measurements cover the region of photon energy from 200 to 450 MeV and the region of the center-of-mass pion polar angle from 100 to 140 degrees. The results obtained are compared with predictions of several theoretical models.
We present experimental results for T20 component of the tensor analyzing power for incoherent π− photoproduction on a deuteron. The experiment was performed on an internal tensor-polarized gas ...deuterium target of the VEPP-3 electron storage ring in 2021 using the proton-proton coincidence method. The data are compared with the results of numerical simulation.
Abstract
Using the 1.32
$$\hbox {pb}^{-1}$$
pb
-
1
statistics collected at the
$$J/\psi $$
J
/
ψ
peak with the KEDR detector at the VEPP-4M
$$e^{+}e^{-\, }$$
e
+
e
-
collider, we measured the ...branching fractions of
$$J/\psi $$
J
/
ψ
meson decays to the final states 2(
$$\pi ^{+}\pi ^{-})\pi ^{0}$$
π
+
π
-
)
π
0
,
$$K^{+}K^{-}\pi ^{+}\pi ^{-}\pi ^{0}$$
K
+
K
-
π
+
π
-
π
0
, 2(
$$\pi ^{+}\pi ^{-})$$
π
+
π
-
)
and
$$K^{+}K^{-}\pi ^{+}\pi ^{-}$$
K
+
K
-
π
+
π
-
. The results obtained for the decays
$$J/\psi \rightarrow $$
J
/
ψ
→
2(
$$\pi ^{+}\pi ^{-})\pi ^{0}$$
π
+
π
-
)
π
0
,
$$J/\psi \rightarrow K^{+}K^{-}\pi ^{+}\pi ^{-}\pi ^{0}$$
J
/
ψ
→
K
+
K
-
π
+
π
-
π
0
contradict the measurements performed by other groups in the last century, but agree well with recent results of BABAR and BESIII collaborations.
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