Electrophysical methods of separation of metal cations in the moving salts solution

The results of experiments on the excitation of the phenomenon of selective drift of solvated ions under the influence of an external "asymmetric" electric field to the circulating solution of calcium chloride and magnesium salts in a polar liquid dielectric - water are shown. The purpose of the experiments was to determine the influence of the field frequency and amplitude of the field strength on the excitation phenomenon, and the study of the operating characteristics of the testing apparatus - a dividing cell. The dependences of the separation efficiency of solvated cations from the frequency of the external field and the excitation threshold of the phenomenon from the field strength in the separation cell are defined

OSTEOCONDUCTIVE COMPOSITE MATERIALS BASED ON POLY-L-LACTIDE AND NANOCRYSTALLINE CELLULOSE MODIFIED WITH POLY(GLUTAMIC ACID)

The aim of this work was to obtain the series of composite polymeric materials based on poly-L-lactide (PLLA) with different contents of hydrophilic nanocrystalline cellulose (NCC) and modified with poly(glutamic acid) (PGlu) nanocrystalline cellulose (NCC-PGlu) (5, 10 and 15 wt%) as fillers. For this purpose several methods for modifying NCC with poly(glutamic acid) were tested. The best result was demonstrated by the partial oxidation of the NCC and the subsequent interaction of the obtained aldehyde NCC groups with the terminal amino groups of PGlu.The research was carried out with the use of some equipment of the Research Park of St. Petersburg State University: “Interdisciplinary Center for Nanotechnology” and “Center for Chemical Analysis and Materials Research”

COMPOSITE POLYMERIC MATERIALS BASED ON POLYCAPROLACTONE WITH ADDITION OF MODIFIED AMINOGRAPHENE FOR TISSUE ENGINEERING

In present work, we have been focused on the preparation of composite polymer materials representing films based on poly-ε-caprolactone (PCL) filled with aminographene modified with poly(glutamic acid) (PGlu). The further preparation of such composites as 3D-materails will allow their application as scaffolds for the bone tissue regeneration.The research was carried out using the equipment of the St. Petersburg State University Research Park: “Center for Chemical Analysis and Materials Research” and ”Interdisciplinary Center for Nanotechnology”

Lower Neutrino Mass Bound from SN1987A Data and Quantum Geometry

A lower bound on the light neutrino mass $m_\nu$ is derived in the framework of a geometrical interpretation of quantum mechanics. Using this model and the time of flight delay data for neutrinos coming from SN1987A, we find that the neutrino masses are bounded from below by $m_\nu\gtrsim 10^{-4}-10^{-3}$eV, in agreement with the upper bound $m_\nu\lesssim$ $({\cal O}(0.1) - {\cal O} (1))$ eV currently available. When the model is applied to photons with effective mass, we obtain a lower limit on the electron density in intergalactic space that is compatible with recent baryon density measurements.Comment: 22 pages, 3 figure

Ground state numerical study of the three-dimensional random field Ising model

The random field Ising model in three dimensions with Gaussian random fields is studied at zero temperature for system sizes up to 60^3. For each realization of the normalized random fields, the strength of the random field, Delta and a uniform external, H is adjusted to find the finite-size critical point. The finite-size critical point is identified as the point in the H-Delta plane where three degenerate ground states have the largest discontinuities in the magnetization. The discontinuities in the magnetization and bond energy between these ground states are used to calculate the magnetization and specific heat critical exponents and both exponents are found to be near zero.Comment: 10 pages, 6 figures; new references and small changes to tex

Tricritical Points in the Sherrington-Kirkpatrick Model in the Presence of Discrete Random Fields

The infinite-range-interaction Ising spin glass is considered in the presence of an external random magnetic field following a trimodal (three-peak) distribution. The model is studied through the replica method and phase diagrams are obtained within the replica-symmetry approximation. It is shown that the border of the ferromagnetic phase may present first-order phase transitions, as well as tricritical points at finite temperatures. Analogous to what happens for the Ising ferromagnet under a trimodal random field, it is verified that the first-order phase transitions are directly related to the dilution in the fields (represented by $p_{0}$). The ferromagnetic boundary at zero temperature also exhibits an interesting behavior: for $0<p_{0}<p_{0}^{*} \approx 0.30856$, a single tricritical point occurs, whereas if $p_{0}>p_{0}^{*}$ the critical frontier is completely continuous; however, for $p_{0}=p_{0}^{*}$, a fourth-order critical point appears. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified; in particular, the Almeida-Thouless line in the plane field versus temperature is shown to depend on the weight $p_{0}$.Comment: 23pages, 7 ps figure

Art and the Twenty-First Century Gift: Corporate Philanthropy and Government Funding in the Cultural Sector

Marcel Mauss’s work on the archaic gift contributes to understandings of corporate and government support of arts organisations, or ‘institutional funding’. His approach allows us to see institutional funding as a gift that is embedded in a system of exchange wherein gifts come with a variety of obligations, and self-interest and disinterestedness are inseparable. The institutional gift operates through money and contracts; nevertheless, it entails obligations to give, to receive and to reciprocate. This system of obligations has been joined, in the contemporary institutional gift, by another obligation: the obligation to ask. Institutional funding of the arts has acquired additional twenty-first century elements. The article elaborates these, using the UK as an example. It also argues that the ambivalence felt by some members of the arts world about institutional funding stems, in large part, from the obligations inherent in the gift. The recent imposition of the neo-liberal model into the arts is an intrinsic part of the exchange between institutional funders and arts organisations. Given that Mauss’s work is strongly anti-liberal and anti-utilitarian, it is ironic that his ideas should prove so useful for understanding a form of twenty-first century gift in which neo-liberalism plays such a crucial role

CAFF CBMP Report No. 19 - Circumpolar Biodiversity Marine Monitoring Plan - background paper

CAFF CBMP Report No. 19 - Circumpolar Biodiversity Marine Monitoring Plan - background pape

CAFF Monitoring Series Report No.3 - Arctic Marine Biodiversity Monitoring Plan (CBMP-MARINE PLAN)

CAFF Monitoring Series Report No.3 - Arctic Council's CAFF Working Group Arctic Marine Biodiversity Monitoring Plan (CBMP-MARINE PLA

Ten-year long-term outcomes of conventional and eversion carotid endarterectomy. Multicenter study

Aim. To analyze the immediate and long-term outcomes of eversion and conventional carotid endarterectomy (CE) with patch angioplasty.Material and methods. For the period from February 1, 2006 to September 1, 2021, the present retrospective multicenter open comparative study included 25106 patients who underwent CE. Depending on the technique of operation, the following groups were formed: group 1 (n=18362) — eversion CE; group 2 (n=6744) — conventional CE with patch angioplasty. The long-term follow-up period was 124,7±53,8 months.Results. In the hospital postoperative period, the groups were comparable in incidence of all complications: lethal outcome (group 1: 0,19%, n=36; group 2: 0,17%, n=12; p=0,89; odds ratio (OR) =1,1; 95% confidence interval (CI) =0,57- 2,11); myocardial infarction (MI) (group 1: 0,15%, n=28; group 2: 0,13%, n=9; p=0,87; OR=1,14; 95% CI=0,53-2,42); stroke (group 1: 0,33%, n=62; group 2: 0,4%, n=27; p=0,53; OR=0,84; 95% CI=0,53-1,32); bleeding with hematoma formation (group 1: 0,39%, n=73; group 2: 0,41%, n=28; p=0,93; OR=0,95; 95% CI=0,61-1,48); internal carotid artery (ICA) thrombosis (group 1: 0,05%, n=11; group 2: 0,07%, n=5, p=0,9; OR=0,8; 95% CI=0,28-2,32). In the long-term follow-up, the groups were comparable only in MI incidence: group 1: 0,56%, n=103; group 2: 0,66%, n=45; p=0,37; OR=0,84; 95% CI=0,59-1,19. All other complications were more frequent after conventional CE with patch angioplasty: all-cause death (group 1: 2,7%, n=492; group 2: 9,1%, n=616; p&lt;0,0001; OR=0,27; 95% CI=0,24-0,3); lethal ischemic stroke (group 1: 1,0%, n=180; group 2: 5,5%, n=371; p&lt;0,0001; OR=0,17; 95% CI=0,14-0,21); non-lethal ischemic stroke (group 1: 0,62%, n=114; group 2: 7,0%, n=472; p&lt;0,0001; OR=0,08; 95% CI=0,06-0,1); ICA restenosis &gt;60%, requiring re-revascularization (group 1: 1,6%, n=296; group 2: 12,6%, n=851; p&lt;0,0001; OR=0,11; 95% CI=0,09-0,12). Thus, the composite endpoint (lethal ischemic stroke + non-lethal ischemic stroke + MI) after conventional CE with patch angioplasty was more than 6 times higher than this parameter of eversion CE: group 1: 2,2%, n=397; group 2: 13,2%, n=888; p&lt;0,0001; OR=0,14; 95% CI=0,12-1,16.Conclusion. Conventional CE with patch angioplasty is not prefer for cerebral revascularization in the presence of hemodynamically significant ICA stenosis due to the high prevalence of deaths, stroke, and ICA restenosis in the long-term follow-up