scholarly journals CONTENT OF SUSPENDED SUBSTANCES IN MACROPRIENT ESTUARIES OF THE WHITE AND BARENTS SEA RIVERS

2021 ◽  
Vol 49 (2) ◽  
pp. 67-79
Author(s):  
I. V. Miskevich ◽  
A. V. Leshchev

The statistical characteristics of the content of suspended matter in the macrotidal estuaries of the Kuloi River with a lateral tributary of the Pocha, the Pyya River (White Sea) and the Chesha River in the Barents Sea. Their maximum values in the surface layers of estuarine waters due to the roiling of bottom sediments by tidal currents can reach a level of 500–4000 mg/l and even more. The typical range of fluctuations in the concentration of suspended matter in such river mouths will be 90–720 mg/l for taiga rivers and 200–1830 mg/l for tundra rivers. The higher turbidity of the estuarine waters of the tundra zone is associated with the degradation of its permafrost soils against the background of the observed climate warming. The relationship between suspended solids and salinity distribution at the mouths of small rivers may differ markedly from the conditions observed at the mouths of medium and large rivers.

2019 ◽  
Vol 59 (6) ◽  
pp. 1089-1092
Author(s):  
I. V. Miskevich ◽  
A. V. Leshchev ◽  
D. S. Moseev ◽  
A. S. Lokhov

In the winter low water season in March and the first week of April 2019, complex hydrological and hydrochemical studies were carried out at the mouths of two small rivers of the White Sea catchment basin (the Mudyuga river, which flows into the Dvina Bay, and the Tamitsa river, which flows into the Onega Bay). The results indicate significant differences in the short-period variability of hydrological and hydrochemical parameters in the winter in the studied river mouths compared with the characteristics observed in the tidal estuaries of large and medium rivers, as well as in the mouths of small rivers of the southern seas.


Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 873
Author(s):  
Dandan Xia ◽  
Liming Dai ◽  
Li Lin ◽  
Huaifeng Wang ◽  
Haitao Hu

The field measurement was conducted to observe the wind field data of West Pacific typhoon “Maria” in this research. With the application of ultrasonic anemometers installed in different heights (10 m, 80 m, 100 m) of the tower, the three dimensional wind speed data of typhoon “Maria” was acquired. In addition, vane-type anemometers were installed to validate the accuracy of the wind data from ultrasonic anemometers. Wind characteristics such as the mean wind profile, turbulence intensity, integral length scale, and wind spectrum are studied in detail using the collected wind data. The relationship between the gust factor and turbulence intensity was also studied and compared with the existing literature to demonstrate the characteristics of Maria. The statistical characteristics of the turbulence intensity and gust factor are presented. The corresponding conclusion remarks are expected to provide a useful reference for designing wind-resistant buildings and structures.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Chaofei Gao ◽  
Yanlong Yu ◽  
Zan Wang ◽  
Wei Wang ◽  
Liwei Zheng ◽  
...  

Based on the slice materials of 35 kV and 110 kV XLPE cables, an experimental platform is built to study the relationship between electrical tree and PDs in XLPE with different voltage levels. There are three significant statistical characteristics of the PDs during the growth of electrical trees. The analysis of the results shows that each growth stage has certain characteristics. Different features existed between the growth of the electrical trees and the PD in the insulation of the 35 and 110 kV cables. Evident characteristics such as large spans of time and frequency were present as the electrical trees grew violently in the equivalent time-frequency diagram at every stage. These results could provide criteria for the identification of the deterioration using PD to monitor cables in service at rated voltages. The results are important for the identification of defects in cable insulation in order to provide an early warning of insulation breakdown in the cables.


Author(s):  
Stepan Dankevych

The problem of ensuring the balanced use of forest lands determines the search for new economic and environmental tools that can influence this process. The need to improve the certification tool as part of the financial and economic mechanism for ensuring balanced forestry land use corresponds to the directions of state policy and European integration intentions of Ukraine, modern requirements of the ecological aspect of forestry land use. The work examines the practice in the field of forest certification in Ukraine from the point of view of balanced land use. Spatial-temporal analysis and assessment of the scale and dynamics of the spread of forest FSC certification in Ukraine has been carried out. The study was formed in three stages: (I) study of changes over time in the volume of forest certification on a national scale, (II) assessment of trends over time for indicators on a regional scale, (III) study of the relationship between individual indicators. The analysis of the impact of FSC-certification of forest management in Ukraine on the environmental indicators of forestry land use based on the results of the correlation between the statistical characteristics of certain economic and environmental indicators, such as the area of certified forests, capital investments, reforestation. Analysis of statistical data showed the relationship between environmental and economic performance over time and changes in specific characteristics on a regional scale. The study makes it possible, on the basis of an objectively existing causal relationship between phenomena and indicators, to identify the course of certain positive or negative processes in forestry land use. Forest certification can play a role in maintaining a balanced use of forest lands, preventing illegal logging, forest degradation and contributing to reforestation and capital investments. The study helps to identify certain key variables that limit the ability of forestry operators to ensure balanced use of forest lands and how forest certification can affect this. Foreign experience in stimulating forest certification has been investigated for the possibility of borrowing the experience of using management tools in order to motivate forest certification in Ukraine. It has been proven that certification is a significant environmental tool for ensuring a balanced level of land use and has the potential for further development.


Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 433 ◽  
Author(s):  
Ang Chen ◽  
Miao Wu

Environmental flows (e-flows) are important for river protection and restoration under degraded ecological conditions. With increasing public desire for and pursuit of sustainable development, e-flows are widely used to reflect the hydrological regime requirements for sustaining freshwater ecosystems and human livelihoods. Over the past 40 years, e-flows implementation has shifted from static minimum flows to dynamic flow components. However, e-flows standards used to manage flow releases from dams are to a great extent based on expert judgement and government supervision. These attributes make it difficult to effectively implement e-flows in the non-stationary world. The primary focus of this paper is to review the history, management systems and scientific basis of e-flows in China. Firstly, the study classifies the development phases into four periods and then analyses the underpinning legal system for e-flows implementation in each period, including the laws, regulations, policies and responsible authorities. Finally, the scientific basis and methods for e-flows determination and assessment were analyzed. The study showed that: (1) e-flows have been officially regarded as ecological flow in China, which evolved from minimum flow, and the contents and connotations are still broadening; (2) currently, there are too many authorities related to e-flows and complicated legal documents in China which lead to ineffective implementation; (3) the scientific basis of e-flows is enriched from the relationship between hydrological alteration and ecological response, so that the practices will be more holistic in China. Despite the successful practices of e-flows implementation in large rivers, there are challenges for implementing future e-flows in small rivers. This study recommended that future e-flows implementation be integrated with sustainable water management by setting clear responsibilities for governments, ministries, and other stakeholders.


2010 ◽  
Vol 22 (3) ◽  
pp. 581-598 ◽  
Author(s):  
Michael Famulare ◽  
Adrienne Fairhall

The relationship between a neuron's complex inputs and its spiking output defines the neuron's coding strategy. This is frequently and effectively modeled phenomenologically by one or more linear filters that extract the components of the stimulus that are relevant for triggering spikes and a nonlinear function that relates stimulus to firing probability. In many sensory systems, these two components of the coding strategy are found to adapt to changes in the statistics of the inputs in such a way as to improve information transmission. Here, we show for two simple neuron models how feature selectivity as captured by the spike-triggered average depends on both the parameters of the model and the statistical characteristics of the input.


Author(s):  
A. D. Woodhead

Describing the migrations and movements of the cod, Gadus callarias L., in the Barents Sea, Trout (1957) suggested that the immature fish carry out a false spawning migration. ‘The pattern of migration of the immatures is basically similar to that of the matures…with increasing age, the immatures’ southerly winter migration approached in length that of the mature cod, as if, in the years immediately prior to maturity they were making a “dummy run” towards the spawning ground.' The seasonal migrations of both the adult and immature cod have been related to changes in the activity of the thyroid gland in this fish (Woodhead, 1959). During the spring of 1956 and 1957, collections of thyroid glands from immature cod were made at stations from Bear Island to the Norwegian coast. It was hoped that a study of these glands might demonstrate further the relationship of the activity of the thyroid gland to the migration of the fish.


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