Contemporary state of glaciers in Chukotka and Kolyma highlands

The purpose of this work is to assess the main parameters of the Chukotka and Kolyma glaciers (small forms of glaciation, SFG): their size and volume, and changes therein over time. The point as to whether these SFG can be considered glaciers or are in transition into, for example, rock glaciers is also presented. SFG areas were defined from the early 1980s (data from the catalogue of the glaciers compiled by V. Sedov) to 2005, and up to 2017: these data were retrieved from satellite images. The maximum of the SGF reduction occurred in the Chantalsky Range, Iskaten Range, and in the northern part of Chukotka Peninsula. The smallest retreat by this time relates to the glaciers of the southern part of the peninsula. Glacier volumes are determined by the formula of S.А. Nikitin for corrie glaciers, based on in-situ volume measurements, and by our own method: the average glacier thickness is calculated from isogypsum patterns, constructed using DEMs of individual glaciers based on images taken from a drone during field work, and using ArcticDEM for others

Radiocarbon-based approach capable of subannual precision resolves the origins of the site of Por-Bajin

Inadequate resolution is the principal limitation of radiocarbon dating. However, recent work has shown that exact-year precision is attainable if use can be made of past increases in atmospheric radiocarbon concentration or so-called Miyake events. Here, this nascent method is applied to an archaeological site of previously unknown age. We locate the distinctive radiocarbon signal of the year 775 common era (CE) in wood from the base of the Uyghur monument of Por-Bajin in Russia. Our analysis shows that the construction of Por-Bajin started in the summer of 777 CE, a foundation date that resolves decades of debate and allows the origin and purpose of the building to be established

Background heat flow values in the region of the Sea of Okhotsk

Particular features of tectonic structure and anomalous distribution of geothermal, geomagnetic, and gravity fields in the region of the Sea of Okhotsk are considered. On the basis of heat flow data, ages of large-scale structures in the Sea of Okhotsk are estimated at 65 Ma for the Central Okhotsk Rise and 36 Ma for the South Okhotsk Basin. Age of the South Okhotsk Basin is confirmed by data on kinematics and corresponds to 50 km thickness of the lithosphere. This is in accordance with thickness value obtained by magnetotelluric soundings. Comparative analysis of model geothermal background and measured heat flow values on the Akademii Nauk Rise is performed. Analysis points to abnormally high (~20%) measured heat flow agrees with high negative gradient of gravity anomalies. Estimates of deep heat flow and basement age of riftogenic basins in the Sea of Okhotsk were carried out in the following areas: Deryugin Basin (18 Ma, Early Miocene), TINRO Basin (12 Ma, Middle Miocene), and West Kamchatka Basin (23 Ma, Late Oligocene). Temperatures at boundaries of the main lithological complexes of the sedimentary cover are calculated and zones of oil and gas generation are defined. On the basis of geothermal, magnetic, structural, and other geological-geophysical data a kinematic model of the region of the Sea of Okhotsk for period of 36 Ma was calculated and constructed

Sorption recovery of copper (II) and zinc (II) from chloride aqueous solutions

The present investigation is devoted to simultaneous sorption recovery of copper (II) and zinc (II) ions on some commercial anion exchangers with different physical-chemical properties. The initial concentrations of zinc and copper were 1-3 mmol L-1 and the recovery was carried out in 0.01 M and 2 M hydrochloric acid solutions. It was shown that the investigated anion exchangers possess good sorption and kinetic properties. After the recovery of copper and zinc from strong acidic solutions, their selective elution was carried out by means of 2 M hydrochloric acid solution (zinc recovery) and 2 M ammonia solution (copper recovery). In weak acidic solutions, copper and zinc were separated during sorption, as zinc sorption did not proceed in this case. The subsequent copper (II) elution was carried out by 2 M ammonia solution. The anion exchangers Purolite S985, Purolite A500 and AM-2B can be recommended for zinc and copper recovery from acidic industrial solutions and waste water

Pressure driven spin transition in siderite and magnesiosiderite single crystals

Iron-bearing carbonates are candidate phases for carbon storage in the deep Earth and may play an important role for the Earth’s carbon cycle. To elucidate the properties of carbonates at conditions of the deep Earth, we investigated the pressure driven magnetic high spin to low spin transition of synthetic siderite FeCO$_3$ and magnesiosiderite (Mg$_{0.74}$Fe$_{0.26}$)CO$_3$ single crystals for pressures up to 57 GPa using diamond anvil cells and x-ray Raman scattering spectroscopy to directly probe the iron 3d electron configuration. An extremely sharp transition for siderite single crystal occurs at a notably low pressure of 40.4 ± 0.1 GPa with a transition width of 0.7 GPa when using the very soft pressure medium helium. In contrast, we observe a broadening of the transition width to 4.4 GPa for siderite with a surprising additional shift of the transition pressure to 44.3 ± 0.4 GPa when argon is used as pressure medium. The difference is assigned to larger pressure gradients in case of argon. For magnesiosiderite loaded with argon, the transition occurs at 44.8 ± 0.8 GPa showing similar width as siderite. Hence, no compositional effect on the spin transition pressure is observed. The spectra measured within the spin crossover regime indicate coexistence of regions of pure high- and low-spin configuration within the single crystal

Hyperon signatures in the PANDA experiment at FAIR

We present a detailed simulation study of the signatures from the sequential decays of the triple-strange pbar p -> Ω+Ω- -> K+ΛbarK- Λ -> K+pbarπ+K-pπ- process in the PANDA central tracking system with focus on hit patterns and precise time measurement. We present a systematic approach for studying physics channels at the detector level and develop input criteria for tracking algorithms and trigger lines. Finally, we study the beam momentum dependence on the reconstruction efficiency for the PANDA detector