The hadronic corrections to the muon anomalous magnetic moment
a
μ
, due to the gauge-invariant set of diagrams with dynamical quark loop light-by-light scattering insertions, are calculated in the ...framework of the nonlocal chiral quark model. These results complete calculations of all hadronic light-by-light scattering contributions to
a
μ
in the leading order in the
1
/
N
c
expansion. The result for the quark loop contribution is
a
μ
HLbL
,
Loop
=
11.0
±
0.9
×
10
-
10
,
and the total result is
a
μ
HLbL
,
N
χ
QM
=
16.8
±
1.2
×
10
-
10
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
This study presents chemical resistance tests for three different grades of polyurethane bicomponent compounds: PolyFlex 80A, Silagerm 6080 and Advaform Mark 80. Samples of polyurethane ...bicomponent compounds were prepared in the form of squares, with a thickness not exceeding 3 mm. They were placed in previously prepared containers with aggressive technical me-dia: Lazurit herbicide, Rakurs fungicide and MAXCUT HD SAE 30 mineral motor oil. These technical media were selected taking into account the processing of agricultural legumes, and the concentration of preparations was calculated specifically for soybeans. The selected mineral motor oil MAXCUT HD SAE 30 is used in many pumping equipment used in the agri-cultural industry. According to the results of the study, it was proved that the greatest effect on the samples is exerted by the herbicide “Lazurit”, in which they swell and increase in weight. The experiment carried out to evaluate the chemical resistance of polyurethane compounds showed that the best materi-al for the manufacture of diaphragms used in piston diaphragms is Adva-form Mark 80. This type of two-component polyurethane compound has the best chemical resistance to the investigated chemically active substances.
As is established here, the classical interpretation of the first law of thermodynamics is inconsistent with the processes actually occurring in piston-based internal combustion engines. A new ...interpretation is proposed.
The impact of the laser spot dimensions on the laser-induced breakdown spectroscopy (LIBS) analysis of heterogeneous samples was studied in detail. The study was stimulated by comparing the ...analytical performance of three LIBS instrument types that have potential utilization at different stages of agricultural material control: a hand-held analyzer, laboratory LIBS system, and an online industrial system installed on a production line (conveyer belt,
etc.
). Laser spot diameters (120 to 1100 μm) with the same averaged energy density were utilized for heterogeneous sample analysis of materials with particle sizes from 20 to 300 μm; thus, every spot could probe from one to a few hundred particles. Few-hundred-point LIBS maps were generated to construct calibration curves with different numbers of averaged spots (from 4 to 400). The analytical capabilities were compared in terms of the linearity and accuracy of determination. For large spot sampling, a better linearity and better accuracy of zinc determination in soybean grist were achieved compared to the small spot sampling. It was demonstrated for the first time that a few dozen LIBS spots should be probed to achieve a representative analysis in the case of heterogeneous material LIBS analysis (such as plants or its products) while only a few spots are generally sampled in the published LIBS studies to date.
Improving the laser-induced breakdown spectroscopy analysis of heterogeneous agricultural samples utilizing large laser spotting.
The light-by-light contribution from the lightest neutral pseudoscalar and scalar mesons to the anomalous magnetic moment of muon is calculated in the framework of the nonlocal
SU
(3)×
SU
(3) quark ...model. The model is based on chirally symmetric four-quark interaction of the Nambu–Jona-Lasinio type and Kobayashi–Maskawa–’t Hooft
U
A
(1) breaking six-quark interaction. Full kinematic dependence of vertices with off-shell mesons and photons in intermediate states in the light-by-light scattering amplitude is taken into account. The small positive contributions from the scalar mesons stabilize the total result with respect to change of model parameters and reduces to
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We study the pair production of Bc mesons in the photon-photon interaction in the framework of perturbative quantum chromodynamics and the relativistic quark model. The production amplitudes of a ...pair of pseudoscalar and vector Bc mesons are constructed in the nonrelativistic approximation and taking into account relativistic effects. Relativistic corrections related to the relative motion of heavy quarks in the production amplitude, as well as in the wave function of the bound state of heavy quarks, are taken into account. Analytical expressions are constructed for the relativistic differential and total cross sections for the pair Bc meson production. Based on them, numerical values of the production cross sections are obtained for various energies and scattering angles.
Investigation is devoted to the optimization of light spectrum and intensity used for red mustard growing. Notably, most of the studies devoted to red mustard growing were conducted on micro-greens, ...which is not enough for the development of methods and recommendations for making the right choices about the irradiation parameters for full-cycle cultivation. In this study, we tested four models of LED with different ratios of blue, green red and far red radiation intensity: 12:20:63:5; 15:30:49:6; 30:1:68:1, in two values of photon flux density (PFD)—120 and 180 µmol m−2 s−1—to determine the most effective combination for red mustard growing. The study was conducted in a container-type climate chamber, where the red leaf mustard was cultivated in hydroponics. On the 30th day of cultivation, the plant’s morphological, biochemical and chlorophyll fluorescence parameters, and reflection coefficients were recorded. The results indicated that the PFD 120 µmol m−2 s−1 had a worse effect on both mustard leaf biomass accumulation and nitrate concentration (13–30% higher) in the plants. The best lighting option for growing red mustard was the blue–red spectrum, as the most efficient in terms of converting electricity into biomass (77 Wth/g). This light spectrum contributes to plant development with a larger leaf area (60%) and a fresh mass (54%) compared with the control, which has a maximum similarity in spectrum percentage to the sunlight spectrum. The presence of green and far red radiation with the blue–red light spectrum in various proportions at the same level of PFD had a negative effect on plant fresh mass, leaf surface area and photosynthetic activity. The obtained results could be useful for lighting parameters’ optimization when growing red mustard in urban farms.
The light-by-light contribution to the anomalous magnetic moment of muon (
g
−2)
μ
from the hadronic exchanges in the neutral pseudoscalar meson channel is calculated in the nonlocal chiral quark ...model. The full kinematic dependence of the meson two-photon vertices from the virtualities of the mesons and photons is taken into account. It is demonstrated that the effect of the full kinematic dependence in the meson–photon vertices is to reduce the contribution of pseudoscalar exchanges comparing with the most of previous estimates and the result is
. The status of various phenomenological and QCD short-distance constraints is discussed and the comparison with the predictions of other models is performed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Parameters of illumination including the spectra, intensity, and photoperiod play an important role in the cultivation of plants under greenhouse conditions, especially for vegetables such as ...lettuce. We previously showed that illumination by a combination of red, blue, and white LEDs with a high red light intensity, was optimal for lettuce cultivation; however, the effect of the photoperiod on lettuce cultivation was not investigated. In the current work, we investigated the influence of photoperiod on production (total biomass and dry weight) and parameters of photosynthesis, respiration rate, and relative chlorophyll content in lettuce plants. A 16 h (light):8 h (dark) illumination regime was used as the control. In this work, we investigated the effect of photoperiod on total biomass and dry weight production in lettuce plants as well as on photosynthesis, respiration rate and chlorophyll content. A lighting regime 16:8 h (light:dark) was used as control. A shorter photoperiod (8 h) decreased total biomass and dry weight in lettuce, and this effect was related to the suppression of the linear electron flow caused by the decreasing content of chlorophylls and, therefore, light absorption. A longer photoperiod (24 h) increased the total biomass and dry weight, nevertheless an increase in photosynthetic processes, light absorption by leaves and chlorophyll content was not recorded, nor were differences in respiration rate, thus indicating that changes in photosynthesis and respiration are not necessary conditions for stimulating plant production. A simple model to predict plant production was also developed to address the question of whether increasing the duration of illumination stimulates plant production without inducing changes in photosynthesis and respiration. Our results indicate that increasing the duration of illumination can stimulate dry weight accumulation and that this effect can also be induced using the equal total light integrals for day (i.e., this stimulation can be also caused by increasing the light period while decreasing light intensity). Increasing the duration of illumination is therefore an effective approach to stimulating lettuce production under artificial lighting.
Abstract
The paper provides information on the causes of failures in automotive equipment and shows the ways to determine failures using digital technologies introduced into the diagnostic process. ...The implementation of forecasting as a separate stage in the process of diagnosing automotive equipment using machine learning technologies in the form of neural networks is analyzed. The results of the study reflect that the neural network while analyzing a huge amount of data received during remote diagnostics is able to more reliably predict failures of automotive equipment.
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