Interannual variability of thermal state of the cold subsurface layer in the Okhotsk Sea

Long-term variability of the cold subsurface water (CSW) in the Okhotsk Sea is analyzed on the base of all available oceanographic data collected in March through August of 1946-2015 (total 65,742 stations). The Integral Heat Content (IHC) is calculated for each station and average annual IHC anomalies of the cold subsurface water are determined by month and by 2-degree grid. The IHC anomaly series are analyzed using the EOF analysis. Cycles with period of approximately 30 years are revealed in the variations of the subsurface layer heat content. Thus, in the 1946-1950, its temperature decreased, but it grew since 2009-2010 to 2015. The warming of CSW was also observed in the 1951-1964 and 1978-1994, while the cooling was in the 1965-1977 and 1995-2008. Based on this criterion, the CSW thermal condition in certain years is classified as «extremely cold» in 2001, as «cold» in 1949, 1950, 1951, 1958, 1959, 1960, 1966, 1967, 1969, 1973, 1976, 1977, 1978, 1980, 1999, 2000, 2010, 2012, as «normal» in 1946, 1952, 1953, 1954, 1955, 1957, 1961, 1962, 1965, 1970, 1971, 1972, 1975, 1979, 1982, 1983, 1985, 1986, 1988, 1989, 1990, 1993, 1995, 1996, 1998, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2013, 2014, as «warm» in 1948, 1956, 1964, 1968, 1974, 1981, 1984, 1987, 1991, 1992, 1994, 1997, 2015, and as «extremely warm» in 1963. Statistically significant correlation is found between changes of the CSW thermal conditions and long-term variations of atmosphere and ocean climate indices, as well as local patterns of the atmosphere-ice-ocean interaction in the Okhotsk Sea and adjacent onshore and offshore areas of Asia and the Pacific Ocean

Parameters of the upper mixed layer and thermocline layer and chlorophyll- <i>a </i>in the western deep basin of the Bering Sea in summer and fall of 2002-2013

Spatial distribution and seasonal and interannual variability are determined for parameters of the upper mixed layer and seasonal thermocline in the western deep basin of the Bering Sea in summer and fall of 2002-2013 and compared with chlorophyll- a concentration at the sea surface. The mixed layer is formed by solar heating of the sea surface and wind mixing. Its thickness doesn’t exceed 10-15 m in summer but increases up to 25-40 m in fall. The thermocline becomes deeper from summer to fall, too, in particular its lower bound that sinks from 37 to 48 m, on average; however, its thickness decreases from 20-25 to 16-22 m and temperature and density gradients increase from 0.23-0.25 to 0.37-0.45 °C/m and from 0.032 to 0.062 units/m, respectively, that means that the thermocline becomes steadier. Tendency to cooling was observed for both layers in the last decade, the process was more visible in autumn, with a shift at the upper bound of thermocline (from the mean temperature of 9.8 °C in 2002-2006 to the mean temperature of 8.4 °C in 2007-2013) and gradual decreasing at its lower bound (from 3.3 °C in 2003 to 2.1 °C in 2013), and not so obvious in summer. Year-to-year fluctuations of salinity in summer/autumn were within the limits 32.77-33.03/32.60-32.96 psu for the upper bound of the thermocline and 32.98-33.14/33.06-33.13 psu for its lower bound and had slight negative tendency. In both seasons, the mixed layer depth has significant negative correlation with the temperature at the upper bound of the thermocline (R2 = 0.6) and the temperature at the lower bound of the thermocline correlates significantly with salinity at its both bounds (R2 > 0.4). Spring bloom of chlorophyll- a has no relationship neither with temperature in the mixed layer in April and May, nor with the rate of warming between these months. Strong fall bloom of chlorophyll- a develops if the fall cooling begins in conditions of high temperature at the sea surface (> 6 °C) that negatively depends on the mixed layer thickness, so slow cooling and delay of the fall mixing are favorable for chlorophyll- a blooming in autumn

Proof of projective Lichnerowicz conjecture for pseudo-Riemannian metrics with degree of mobility greater than two

We prove an important partial case of the pseudo-Riemannian version of the projective Lichnerowicz conjecture stating that a complete manifold admitting an essential group of projective transformations is the round sphere (up to a finite cover).Comment: 32 pages, one .eps figure. The version v1 has a misprint in Theorem 1: I forgot to write the assumption that the degree of mobility is greater than two. The versions v3, v4 have only cosmetic changes wrt v

Unexpected Temperature Behavior of Polyethylene Glycol Spacers in Copolymer Dendrimers in Chloroform

We have studied copolymer dendrimer structure: carbosilane dendrimers with terminal phenylbenzoatemesogenic groups attached by poly(ethylene) glycol (PEG) spacers. In this system PEG spacers areadditional tuning to usual copolymer structure: dendrimer with terminal mesogenic groups. Thedendrimer macromolecules were investigated in a dilute chloroform solution by 1H NMR methods(spectra and relaxations). It was found that the PEG layer in G = 5 generations dendrimer is “frozen”at high temperatures (above 260 K), but it unexpectedly becomes “unfrozen” at temperatures below250 K (i.e., melting when cooling). The transition between these two states occurs within a smalltemperature range (~10 K). Such a behavior is not observed for smaller dendrimer generations (G = 1and 3). This effect is likely related to the low critical solution temperature (LCST) of PEG and is caused bydendrimer conformations, in which the PEG group concentration in the layer increases with growing G.We suppose that the unusual behavior of PEG fragments in dendrimers will be interesting for practicalapplications such as nanocontainers or nanoreactors.</p

Technical project of complex fast cycle heat treatment of hydrogenous coal preparation

Problems of heat-treated milled hydrogenous coal preparation site creation in leading fast cycle heat treatment complex were considered. Conditions for effective use of electrostatic methods of heat-treated milled hydrogenous coal preparation were set. Technical project of heat treatment of milled hydrogenous coal preparation site was developed including coupling of working equipment complex on fast heat treatment and experimental samples of equipment being designed for manufacturing. It was stated that methods of electrical separation are used for heat-treated milled hydrogenous coal preparation with effective ways of organic and mineral components separation. Laboratory test for determination of optimal separation size sent into separators of heat-treated milled hydrogenous coal were made

3D printing using Ti-Al nanopowders: mechanisms of structure formation

In the presented research work, 3D materials were fabricated by additive moulding by means of extrusion of a mixture of high filled polymers and nanopowders of Ti-Al intermetallides with subsequent sintering at 1100 ± 20 °C, 1200 ± 20 °C and 1250 ± 20 °C (MEAM-HP process). Nanopowders of Ti-Al intermetallides were obtained by the electrical explosion of intertwined aluminium and titanium wires. It was found that the structure of the materials comprises an AlTi matrix with Ti2AlN MAX-phase particles distributed within it, surrounded by a composite layer of Ti3Al- Ti2AlN. Sintering temperature increases led to changes in the concentration of TiAl, Ti3Al and Ti2AlN phases in the samples. Besides that, aluminium oxide particles were discovered in the structure of the materials. It was found that as the sintering temperature was increased from 1100 ± 20 °C to 1250 ± 20 °C, the average microhardness of the samples increased from 193 to 690 HV0.1

Efficiency of Finding Muon Track Trigger Primitives in CMS Cathode Strip Chambers

In the CMS Experiment, muon detection in the forward direction is accomplished by cathode strip chambers~(CSC). These detectors identify muons, provide a fast muon trigger, and give a precise measurement of the muon trajectory. There are 468 six-plane CSCs in the system. The efficiency of finding muon trigger primitives (muon track segments) was studied using~36 CMS CSCs and cosmic ray muons during the Magnet Test and Cosmic Challenge~(MTCC) exercise conducted by the~CMS experiment in~2006. In contrast to earlier studies that used muon beams to illuminate a very small chamber area ($< \! 0.01$~m$^2$), results presented in this paper were obtained by many installed CSCs operating {\em in situ} over an area of $\approx \! 23$~m$^2$ as a part of the~CMS experiment. The efficiency of finding 2-dimensional trigger primitives within 6-layer chambers was found to be~$99.93 \pm 0.03\%$. These segments, found by the CSC electronics within $800$~ns after the passing of a muon through the chambers, are the input information for the Level-1 muon trigger and, also, are a necessary condition for chambers to be read out by the Data Acquisition System

Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron

Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.ISSN:1434-6044ISSN:1434-605