Estimating the First-year Corrosion Losses of Structural Metals for Continental Regions of the World

The knowledge of the first-year corrosion losses of metals (K1) in various regions of the world is of great importance in engineering applications. The K1 values are used to determine the categories of atmospheric corrosivity, and K1 is also the main parameter in models for the prediction of long-term corrosion losses of metals. In the absence of experimental values of K1, their values can be predicted on the basis of meteorological and aerochemical parameters of the atmosphere using the dose-response functions (DRF). Currently, the DRFs presented in ISO 9223:2012(E) /1/ standard are used for predicting K1 in any region of the world, along with the unified DRFs /2/ and the new DRFs /3/. The predicted values of corrosion losses (K1pr) of carbon steel, zinc, copper and aluminum obtained by various DRFs for various continental regions of the world are presented. In this work we used the atmosphere corrosivity parameters and experimental data on the corrosion losses of metals for the first year of exposure (K1exp) for the locations of the tests performed under the international UN/ECE program, the MICAT project, and the Russian program. For the first time, a comparative assessment of the reliability of various DRFs is given by comparing the values of K1pr and K1ex using graphical and statistical methods. The statistical indicators of reliability of predicting the corrosion losses of metals are calculated for various categories of atmosphere corrosivity. It is shown that the new dose-response functions offer the highest reliability for all categories of atmosphere corrosivity

Remote detection of traces of high energetic materials

The possibility of remote detection of traces of high energetic materials using laser fragmentation/laser-induced fluorescence (LF/LIF) method is studied. Experimental data on the remote visualization of traces of trinitrotoluene, hexogen, composition B, octogen, and tetryl obtained at a distance of 5 m with a scanning lidar detector of traces of high energetic materials are presented

Shape memory effect and superelasticity in [001] single crystals of FeNiCoAlNb(B) alloys

In given paper presents data research of influence of boron on the functional properties - the shape memory effect and superelasticity in the [001] single crystals FeNiCoAlNb(B) alloys aged at 973 K for 5 hours. On the [001] single crystals FeNiCoAlNbB at aging at T = 973 K for 5 hour, it is shown, that boron leads to decrease the start Ms temperature of γ-α' martensitic transformation on cooling, to the development of γ-α' stress induced martensitic transformation at higher stress at one test temperature and to increase of thermal ΔT and stress Δσ hysteresis is compared to [001] crystals without boron

Aspects for efficient wide spectral band THz generation via CO2 laser down conversion

Detailed model study of THz generation by CO2 laser down-conversion in pure and solid solution crystals GaSe1-xSx is carried out for the first time. Both forward and backward collinear interactions of common (eo-e, oe-e, oe-o, oo-e, ee-o) and original (ee-e, oo-o) types are considered. Possibility of realization, phase matching angles and figure of merits are estimated for line mixing within 9 μm and 10 μm emission bands, as well between them. Dispersion properties of o- and e-wave refractive indices and absorption coefficients for GaSe, GaS and GaSe1-xSx crystals were preliminary measured by THz-TDS, approximated in the equation form and then used in the study. Estimated results are presented in the form of 3-D figures that are suitable for rapid analyses of DFG parameters. The most efficient type of interaction is eo-o type. Optimally doped (x = 0.09-0.13) GaSe1-xSx crystals are from 4 to 5 times more efficient at limit pump intensity than not doped GaSe crystals

Effect of carbon alloying on hydrogen embrittlement of a Cantor alloy

We have investigated the effect of hydrogen-charging on the mechanical properties and fracture mechanisms of high-entropy alloys Fe20Mn20Cr20Ni20Co20 and Fe20Mn20Cr20Ni20Co19C1 (at.%). Both alloys have a coarse-grained single-phase face-centered cubic (fcc) structure. It was found that doping with carbon decreases the content of hydrogen absorbed by the specimens during electrochemical hydrogen-charging (in a 3 % NaCl water solution, at j =10 mA / cm2 for 50 h): 134 wppm and 63 wppm for carbon-free and carbon-doped alloy, respectively. Hydrogen-charging contributes to an increase in the yield strength and a decrease in the ductility of the alloys. Despite the lower concentration of dissolved hydrogen, the hydrogen-associated solid-solution strengthening of the carbon-doped alloy is higher than that in the interstitial-free alloy. The hydrogen embrittlement index, IH =17 %, for carbon-alloyed specimens is lower than IH = 25 % for interstitial-free specimens. In both alloys, the hydrogen-affected surface layers of the specimens fracture in a similar brittle mode — intergranular fracture dominates

Acoustic emission and DSC investigations of anomalous stress-stain curves and burst like shape recovery of Ni49Fe18Ga27Co6 shape memory single crystals

Simultaneous acoustic emission, AE, and DSC measurements under compression along [110]A direction were carried out on Ni49Fe18Ga27Co6 shape memory single crystals. The compression resulted in anomalous stressstrain loops with stress drops/jumps on it, reflecting a sudden formation/dissolution of a more stable (detwinned) martensite structural modification than the thermally induced (twinned) one. The final detwinned martensite, obtained below a certain temperature, was stable even after downloading: during heating it showed a burst-like recovery at about 35K higher transformation temperature than that of the thermally induced one, with an audible click. It was obtained that the number of acoustic events showed strong asymmetry: e.g. for stress induced transformations the number of hits for uploading was larger. Simultaneous measurements of stress-time curves and AE versus time revealed that in the nucleation/dissolution processes in both (up and down) directions, as an intermediate step, the twinned martensite was first formed and resulted in additional AE events. This was interpreted by the easy as well as difficult nucleation of the twinned and detwinned martensites, respectively. The stress drops on the uploading stress-strain curve were attributed to subsequent nucleation of the detwinned martensite from the twinned modification and were followed by a sharp decrease of the AE activity. This indicated that the formation of detwinned martensite is a sudden, fast process and can take place without significant elastic energy storage. This was also in agreement with the fact that during burst like thermal recovery the width of the transition was very small (Af ≅ As). Similarly, during downloading the stress jumps were interpreted as sudden dissolutions of the detwinned phase by retwinning and at all stress jumps there were local maxima on the AE activity curve

The cyclic stability of rubber-like behaviour in stress-induced martensite aged Ni49Fe18Ga27Co6 (at.%) single crystals

In present work, the cyclic stability of the rubber-like behaviour (RLB) was investigated in Ni49Fe18Ga27Co6 (at. %) single crystals. Crystals were aged in the martensite phase at 423 K for 1 h under a compressive stress of 450 MPa, applied along the [110]B2[100]L10-direction. The RLB was induced by a preliminary chemical stabilization of the oriented L10-martensite during stress-induced martensite aging (SIM-aging) and following the reversible reorientation of martensitic variants under a compressive stress applied along the [001]B2[001]L10-direction. The high cyclic stability of the RLB was obtained in 200 loading/unloading cycles, due to the low reorientation stresses of the L10-martensite variants (no higher than 140 MPa) and the high strength properties of the L10-martensite (~1.6 GPa). The irreversible strain after 200 cycles did not exceed 0.6%. An increase in the number of cycles did not lead to the effect of destabilization of the L10-martensite

Состояние военно-научных библиотек накануне Первого Всероссийского съезда по библиотечному делу. (К 110-летию со дня проведения съезда)

For the first time, based on archival and prerevolutionary publications, the survey of military research libraries before the First All-Russian Library Congress held on June 1–7, 1911, is presented. The questionnaires filled-in by military librarians enable to reconstruct the state-of-the-art, local regulations and orders, collections quantitative indicators and arrangement, physical space, fire protection, staffing. Work hours. The study significantly expands the knowledge of the status of military research libraries by 1911, of their facilities, librarians’ expertise, and library services.The findings will be useful for librarians in user services, responsible for collection arrangement, and for library historians investigating in prerevolutionary librarianship; for library surveyors; curators of library events, e. g. congresses, forums, webinars, etc.На основе архивных и дореволюционных опубликованных источников впервые представлены итоги анкетирования, посвящённого изучению состояния военно-научных библиотек перед Первым Всероссийским съездом по библиотечному делу, который состоялся 1–7 июня 1911 г. Анкеты, заполненные сотрудниками военно-научных библиотек, позволяют довольно подробно реконструировать состояние библиотек, в том числе действовавшие локальные нормативные организационно-распорядительные документы, количественные показатели фонда и его расстановку, характеристику занимаемого помещения, противопожарную охрану, штатное расписание, режим работы. Проведённое исследование значительно расширило представление о состоянии военно-научных библиотек к 1911 г., их материально-технической базе, профессионализме сотрудников, уровне библиотечного обслуживания.Полученные результаты будут полезны библиотекарям при решении задач расстановки фонда, ликвидации задолженностей читателей и организации очереди на востребованные издания; историкам – для понимания уровня развития дореволюционного библиотечного дела; организаторам опросов, респондентами которых являются библиотеки; кураторам различных библиотековедческих мероприятий – съездов, форумов, вебинаров и др

Wildfire smoke in the Siberian Arctic in summer: source characterization and plume evolution from airborne measurements

We present airborne measurements of carbon dioxide (CO<sub>2</sub>), carbon monoxide (CO), ozone (O<sub>3</sub>), equivalent black carbon (EBC) and ultra fine particles over North-Eastern Siberia in July 2008 performed during the YAK-AEROSIB/POLARCAT experiment. During a "golden day" (11 July 2008) a number of biomass burning plumes were encountered with CO mixing ratio enhancements of up to 500 ppb relative to a background of 90 ppb. Number concentrations of aerosols in the size range 3.5–200 nm peaked at 4000 cm<sup>−3</sup> and the EBC content reached 1.4 μg m<sup>−3</sup>. These high concentrations were caused by forest fires in the vicinity of the landing airport in Yakutsk where measurements in fresh smoke could be made during the descent. We estimate a combustion efficiency of 90 ± 3% based on CO and CO<sub>2</sub> measurements and a CO emission factor of 65.5 ± 10.8 g CO per kilogram of dry matter burned. This suggests a potential increase in the average northern hemispheric CO mixing ratio of 3.0–7.2 ppb per million hectares of Siberian forest burned. For BC, we estimate an emission factor of 0.52 ± 0.07 g BC kg<sup>−1</sup>, comparable to values reported in the literature. The emission ratio of ultra-fine particles (3.5–200 nm) was 26 cm<sup>−3</sup> (ppb CO)<sup>−1</sup>, consistent with other airborne studies. <br><br> The transport of identified biomass burning plumes was investigated using the FLEXPART Lagrangian model. Based on sampling of wildfire plumes from the same source but with different atmospheric ages derived from FLEXPART, we estimate that the e-folding lifetimes of EBC and ultra fine particles (between 3.5 and 200 nm in size) against removal and growth processes are 5.1 and 5.5 days respectively, supporting lifetime estimates used in various modelling studies