Research into oil film coating of a steel pipe interior by oil mist blowing

Corrosion protection is one of the most frequently addressed issues in metallurgic and engineering applications. Oil film coating of inaccessible areas such as interior of a steel pipe is technically complicated. Because of that, the choice of the interior pipe film coating via oil mist is a viable solution. However, it is necessary to establish what will be the composition of the oil layer and what distance the required oil thickness will span. These are the aspects dealt with in the present paper

Spin Density Matrix Elements in Exclusive ρ0\rho ^0 Meson Muoproduction

We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $\rho ^0$ meson muoproduction at COMPASS using 160~GeV/$c$ polarised $\mu ^{+}$ and $\mu ^{-}$ beams impinging on a liquid hydrogen target. The measurement covers the kinematic range 5.0~GeV/$c^2$ $< W <$ 17.0~GeV/$c^2$, 1.0 (GeV/$c$)$^2$ $< Q^2 <$ 10.0 (GeV/$c$)$^2$ and 0.01 (GeV/$c$)$^2$ $< p_{\rm{T}}^2 <$ 0.5 (GeV/$c$)$^2$. Here, $W$ denotes the mass of the final hadronic system, $Q^2$ the virtuality of the exchanged photon, and $p_{\rm{T}}$ the transverse momentum of the $\rho ^0$ meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons ($\gamma^*_T \to V^{ }_L$) indicate a violation of $s$-channel helicity conservation. Additionally, we observe a dominant contribution of natural-parity-exchange transitions and a very small contribution of unnatural-parity-exchange transitions, which is compatible with zero within experimental uncertainties. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow one to evaluate in a model-dependent way the role of parton helicity-flip GPDs in exclusive $\rho ^0$ production

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ρ0\rho^0 mesons

The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced $\rho^0$ mesons. The analysis is based on the data set collected in deep inelastic scattering in $2010$ using a $160\,\,\rm{GeV}/c$ $\mu^+$ beam impinging on a transversely polarized $\rm{NH}_3$ target. The $\rho^{0}$ mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-$x$ variable, the transverse momentum of the pair and the fraction of the energy $z$ carried by the pair. Indications for positive Collins and Sivers asymmetries are observed

Measurement of P T -weighted Sivers asymmetries in leptoproduction of hadrons

The transverse spin asymmetries measured in semi-inclusive leptoproduction of hadrons, when weighted with the hadron transverse momentum PT , allow for the extraction of important transverse-momentumdependent distribution functions. In particular, the weighted Sivers asymmetries provide direct information on the Sivers function, which is a leading-twist distribution that arises from a correlation between the transverse momentum of an unpolarised quark in a transversely polarised nucleon and the spin of the nucleon. Using the high-statistics data collected by the COMPASS Collaboration in 2010 with a transversely polarised proton target, we have evaluated two types of PT -weighted Sivers asymmetries, which are both proportional to the product of the first transverse moment of the Sivers function and of the fragmentation function. The results are compared to the standard unweighted Sivers asymmetries and used to extract the first transverse moments of the Sivers distributions for u and d quark

Corrigendum to "Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section" [Phys. Lett. B 793 (2019) 188]

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Study of C‐S‐H dehydration due to temperature increase during fires

Concrete is one of the most fire-resistant materials, whose resistance depends on the chemical and structural characteristics of the hydrated calcium silicate (C-S-H) formed in the hydration and hardening process. However, the structure and composition of this C-S-H varies with the time of hydration. The effect of the composition of the calcium silicate on the anhydrous material formed has been studied after subjecting it to an accelerated study of the effect of fire, irradiating it with a CO laser. Changes in the composition of C-S-H can lead to changes in the mechanical properties of the cement. C-S-H samples with different chemical composition (Ca/Si ratios 1 and 2) as well as different synthesis processes (double decomposition and hydrothermal) were studied. The crystalline phases obtained after heating were identified through micro-Raman spectroscopy, which confirmed the formation of anhydrous calcium silicates with the same Ca/Si ratio as the initial one. In C-S-H gels with a Ca/Si ratio of over 1.5, stable Ca (OH) was formed. Scanning electron microscopy/energy dispersive X-ray analysis analysis determined that in the process of heating with the laser, water is lost fast, generating porous structures. Such porosity is higher in materials with a lower Ca/Si ratio.Spanish Ministry of Economy and Competitiveness. Grant Number: FIS2017‐84318‐R European Social Fund. Grant Number: S2018/NMT‐4372 Regional Government of Madrid (CAM). Grant Number: S2013/MIT‐291

Research into oil film coating of a steel pipe interior by oil mist blowing

Corrosion protection is one of the most frequently addressed issues in metallurgic and engineering applications. Oil film coating of inaccessible areas such as interior of a steel pipe is technically complicated. Because of that, the choice of the interior pipe film coating via oil mist is a viable solution. However, it is necessary to establish what will be the composition of the oil layer and what distance the required oil thickness will span. These are the aspects dealt with in the present paper

Fine roots of Picea abies compensate for drought stress in the rainfall reduction experiment

This study evaluates the influence of repeated artificial drought stress on the fine root charac- teristics – including ectomycorrhizae – of Norway spruce [Picea abies (L.) Karst]. The experimental site consisted of two plots in a mature spruce monoculture stand. The water regime at parts of both plots was regulated by shelters and an isolation trench during vegetation season (spring to autumn) since 2010. Root samples were collected during autumn in 2010, 2012, and 2013. Root analyses revealed the effect of drought stress on mycorrhizal root tips changed over time. While a density of active mycorrhizae was about 34% lower in drought-stressed areas compared to nonstressed (control) areas in 2010, it increased by 15% in 2012 and by 22% in 2013 over both plots. We observed the less pronounced effect of drought on a proportion of active mycorrhizae, but it generally followed the pattern of active mycorrhizae density. The density of nonactive mycorrhizae was not influenced by drought but significantly fluctuated during the course of the experiment. Other root characteristics such as the dry mass of fine roots (< 1 mm), the specific length of fine roots (< 1 mm) and the composition of the ectomycorrhizal community (primarily dominated by Amphinema byssoides, Tylospora fibrillosa, Tylopilus felleus, and Cenococcum geophilum) were also not significantly influenced by drought. Our results indicate the ability of Norway spruce fine roots to com- pensate for repeated drought stress of the intermediate intensity