scholarly journals Large Russian Lakes Ladoga, Onega, and Imandra under Strong Pollution and in the Period of Revitalization: A Review

Geosciences ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 492 ◽  
Author(s):  
Tatiana Moiseenko ◽  
Andrey Sharov
Keyword(s):  
Natural State ◽  
Toxic Substances ◽  
North West ◽  
Biological Communities ◽  
Three Stages ◽  
Ecosystem Transformation ◽  
The Stability ◽  
Natural Characteristics ◽  
Northern Species

In this paper, retrospective analyses of long-term changes in the aquatic ecosystem of Ladoga, Onega, and Imandra lakes, situated within North-West Russia, are presented. At the beginning of the last century, the lakes were oligotrophic, freshwater and similar in origin in terms of the chemical composition of waters and aquatic fauna. Three stages were identified in this study: reference condition, intensive pollution and degradation, and decreasing pollution and revitalization. Similar changes in polluted bays were detected, for which a significant decrease in their oligotrophic nature, the dominance of eurybiont species, their biodiversity under toxic substances and nutrients, were noted. The lakes have been recolonized by northern species following pollution reduction over the past 20 years. There have been replacements in dominant complexes, an increase in the biodiversity of communities, with the emergence of more southern forms of introduced species. The path of ecosystem transformation during and after the anthropogenic stress compares with the regularities of ecosystem successions: from the natural state through the developmental stage to a more stable mature modification, with significantly different natural characteristics. A peculiarity of the newly formed ecosystems is the change in structure and the higher productivity of biological communities, explained by the stability of the newly formed biogeochemical nutrient cycles, as well as climate warming.

Long-term vegetation restoration promotes the stability of the soil micro-food web in the Loess Plateau in North-west China

CATENA ◽  
2021 ◽  
Vol 202 ◽  
pp. 105293
Author(s):  
Yang Wu ◽  
WenJing Chen ◽  
Wulan Entemake ◽  
Jie Wang ◽  
HongFei Liu ◽  
...  
Keyword(s):  
Food Web ◽  
Loess Plateau ◽  
Vegetation Restoration ◽  
The Loess Plateau ◽  
West China ◽  
North West ◽  
The Stability

A Study on the Differences of Mechanical Properties between CH4 and CO2 Hydrate-Bearing Sediments

2013 ◽  
Vol 353-356 ◽  
pp. 1240-1244 ◽  
Author(s):  
Yuan Luo ◽  
Yong Chen Song ◽  
Wei Guo Liu ◽  
Jia Fei Zhao ◽  
Yun Fei Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gas Hydrate ◽  
Triaxial Compression ◽  
Triaxial Tests ◽  
Long Term Storage ◽  
Replacement Method ◽  
Three Stages ◽  
The Stability ◽  
Hydrate Bearing Sediments

The CH4-CO2replacement method to recover CH4from hydrate-bearing sediments has received great attention because it enables the long term storage of CO2and is expected to maintain the stability of gas hydrate-bearing sediments. This paper extends our previous study of the stability of CH4hydrate-bearing sediments to CO2hydrate-bearing sediments to evaluate the safety of the CH4-CO2replacement method. Low temperature, high pressure triaxial compression apparatus was used to measure the mechanical properties of CO2hydrate-bearing sediments. The triaxial tests results for CH4and CO2hydrate-bearing sediments were then compared. It was found that the failure mode of both the CO2and CH4hydrate-bearing sediments was a bulging deformation at mid-height on the samples. Moreover, the stress-strain curves of both the CO2and CH4hydrate-bearing sediments appear to be hyperbolic in shape, and could be divided into three stages: the quasi-elastic stage, the hardening stage and the yield stage. However, the strength of the CO2hydrate-bearing sediments was approximately 15% larger than that of the CH4hydrate-bearing sediments under the same conditions. The results imply that the stability of gas hydrate-bearing sediments could be maintained using the CH4-CO2replacement method to recover CH4from these sediments.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

CURRENT STATE AND DEVELOPMENT PERSPECTIVES OF THE CASPIAN SPRAT FISHERIES

2018 ◽  
pp. 69-75
Author(s):  
Tatiana Vasilievna Pomogaeva ◽  
Aliya Ahmetovna Aseinova ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Vjacheslav Petrovich Razinkov
Keyword(s):  
Food Item ◽  
Growth Potential ◽  
North West ◽  
Marine Fishery ◽  
The North ◽  
Current State ◽  
West Part ◽  
Eggs And Larvae ◽  
Intensive Growth

The article presents annual statistical data of the Caspian Research Institute of Fishery. There has been kept track of the long term dynamics of the stocks of three species of Caspian sprat (anchovy, big-eyed kilka, sprat) and investigated a process of substituting a food item of sprats Eurytemora grimmi to a small-celled copepod species Acartia tonsa Dana. According to the research results, there has been determined growth potential of stocks of each species. Ctenophoran-Mnemiopsis has an adverse effect on sprat population by eating fish eggs and larvae. Ctenophoram - Mnemiopsis is a nutritional competitor to the full-grown fishes. The article gives recommendations on reclamation of stocks of the most perspective species - common sprat, whose biological characteristics helped not to suffer during Ctenophoram outburst and to increase its population during change of the main food item. Hydroacoustic survey data prove the intensive growth of common sprat biomass in the north-west part of the Middle Caspian. According to the results of the research it may be concluded that to realize the volumes of recommended sprat catch it is necessary to organize the marine fishery of common sprat at the Russian Middle Caspian shelf.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

Immunological mechanisms of chronic liver lesions under the influence of chemicals

2020 ◽  
pp. 536-537
Author(s):  
G. S. Agzamova ◽  
M. M. Abdullaeva
Keyword(s):  
The Body ◽  
Chronic Liver ◽  
Toxic Substances ◽  
Liver Lesions ◽  
Industrial Chemicals ◽  
Toxic Agent ◽  
Chronic Poisoning ◽  
Immunological Mechanisms ◽  
T System

The immunological profile of chronic liver lesions depending on the toxic agent was studied. It was revealed that chronic poisoning by industrial toxic substances causes changes in the functional state of the T-system of immunity, long-term contact with industrial chemicals leads to increased sensitization to autoantigens of the body.

Influence of internal and external risks on sustainability of financial system of Аltai krai

2018 ◽  
Vol 35 (4) ◽  
pp. 133-136
Author(s):  
R. N. Ibragimov
Keyword(s):  
Sustainable Development ◽  
Financial Stability ◽  
Management Strategy ◽  
Financial System ◽  
Risk Management Strategy ◽  
The Sustainable Development ◽  
The Stability ◽  
The Impact

The article examines the impact of internal and external risks on the stability of the financial system of the Altai Territory. Classification of internal and external risks of decline, affecting the sustainable development of the financial system, is presented. A risk management strategy is proposed that will allow monitoring of risks, thereby these measures will help reduce the loss of financial stability and ensure the long-term development of the economy of the region.

scholarly journals An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

2020 ◽  
Author(s):  
G Lacedelli ◽  
L Malavolta ◽  
L Borsato ◽  
G Piotto ◽  
D Nardiello ◽  
...  
Keyword(s):  
Transit Time ◽  
Time Variation ◽  
Planetary System ◽  
Radial Velocities ◽  
Low Density ◽  
Outer Planets ◽  
Short Period ◽  
The Stability

Abstract Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterisation of the planetary system orbiting the late G dwarf After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm−3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

scholarly journals Effect of Photoinitiator on Precursory Stability and Curing Depth of Thiol-Ene Clickable Gelatin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1877
Author(s):  
Kai-Hung Yang ◽  
Gabriella Lindberg ◽  
Bram Soliman ◽  
Khoon Lim ◽  
Tim Woodfield ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Visible Light ◽  
Rheological Properties ◽  
Swelling Ratio ◽  
Sodium Persulfate ◽  
Photo Polymerization ◽  
Gelation Kinetics ◽  
The Stability ◽  
Over Time

Recent advances highlight the potential of photopolymerizable allylated gelatin (GelAGE) as a versatile hydrogel with highly tailorable properties. It is, however, unknown how different photoinitiating system affects the stability, gelation kinetics and curing depth of GelAGE. In this study, sol fraction, mass swelling ratio, mechanical properties, rheological properties, and curing depth were evaluated as a function of time with three photo-initiating systems: Irgacure 2959 (Ig2959; 320–500 nm), lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP; 320–500 nm), and ruthenium/sodium persulfate (Ru/SPS; 400–500 nm). Results demonstrated that GelAGE precursory solutions mixed with either Ig2959 or LAP remained stable over time while the Ru/SPS system enabled the onset of controllable redox polymerization without irradiation during pre-incubation. Photo-polymerization using the Ru/SPS system was significantly faster (<5 s) compared to both Ig2959 (70 s) and LAP (50 s). Plus, The Ru/SPS system was capable of polymerizing a thick construct (8.88 ± 0.94 mm), while Ig2959 (1.62 ± 0.49 mm) initiated hydrogels displayed poor penetration depth with LAP (7.38 ± 2.13 mm) in between. These results thus support the use of the visible light based Ru/SPS photo-initiator for constructs requiring rapid gelation and a good curing depth while Ig2959 or LAP can be applied for photo-polymerization of GelAGE materials requiring long-term incubation prior to application if UV is not a concern.

Dunhuang scrolls: Innovative storage solutions at the British Library

IFLA Journal ◽  
2021 ◽  
pp. 034003522110237
Author(s):  
Paulina Kralka ◽  
Marya Muzart
Keyword(s):  
Research Library ◽  
British Library ◽  
West China ◽  
North West ◽  
Lotus Sutra ◽  
Storage Solutions ◽  
Storage Facilities

The British Library’s Stein collection contains about 14,000 scrolls, fragments and booklets in Chinese from a cave in the Buddhist Mogao Caves complex near Dunhuang in north-west China. This article describes storage and access solutions for the collection in the context of a busy research library and the currently ongoing Lotus Sutra Manuscripts Digitisation project. The article presents the various technical and organisational challenges that its rehousing presents to the library conservators. Restricted by the existing storage facilities, budget limitations and tight project deadlines, the conservators must provide housing that is adequate for the scroll format, is practical and prevents dissociation, but is also cost- and time-effective. With the best storage practice in mind, they have developed original solutions, balancing the specific housing requirements and constraints. These storage solutions allow the conservators to ensure the long-term safety and accessibility of the collection while laying down a foundation of standardisation that will ensure a homogeneity of approaches for future projects.

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