The growth intra-group variability of perch Perca fluviatilis L., 1758 (Percidae) from Vyacheslavsky Reservoir

Author(s):  
Vladimir N. Krainyuk

The dates on back calculation of perch growth from Vyacheslavsky (Astana) reservoir located in the Akmola oblast of the Republic of Kazakhstan are presented. We studied 2 samples, separated by a time interval approximately equal to duration of one generation. The growth rates of perch in this water body are slower in comparison with previously studied populations. The calculated length of perch have changed little for four years. Sexual and generational variability of growth is not observed. There is a fairly high level of correlation between calculated parameters of body length in adjacent generations, which indicates the stability or insignificant variability of the habitat conditions of perch in the reservoir. It can also show of the immutability of the main influencing factors and their vectors of impact. Taking into account the fact that these factors are a negative, the growth rates of perch in reservoir show a tendency to decrease. Von Bertalanffy’s growth equation performed better in the 2015 sample. This was reflected in the coefficient of Poly-Munro growth efficiency and calculated (theoretical) weight growth. The decrease in the “quality” of population biological parameters indicates beginning of degradation within the group, possibly. But, now observed differences are still at an unreliable level and are characterized only as tendencies. Based on the logical analysis, the main reason for decline in growth rate was termination of commercial fishing, which upset the existing balance in the perch population and caused the so-called “neglect of fishing”.

Author(s):  
Vladimir Nickolaevich Krainyuk ◽  
Saule Zhangirovna Asylbekova ◽  
Azis Vasilyevich Shutkarayev

The reservoirs of the K. Satpayev canal are the important fishery water bodies in the Central Kazakhstan. Some of these reservoirs are inhabited by tench, a fish species relatively widely represented in other water systems of the region. In the reservoirs of the canal this species is not the main commercial one but it has a fairly high commercial value due to its popularity with consumers. As part of the research, the growth indicators of Tinca tinca from 4 reservoirs were evaluated, and the data on its growth from 3 more reservoirs were also provided. These samples differ in efficiency and growth rates. It has been found that there is no sexual or generation variability. Growth rates in successive fish generations strongly correlate with each other, which may indirectly indicate the stability of living conditions. The R. Lee’s phenomenon was not marked. In this regard, the calculation of variables of the von Bertalanffy growth equation was carried out without additional data processing. The highest rates of linear growth were characteristic of Tinca tinca from the reservoir of HS No. 9. However, the effectiveness of its growth scheme was the lowest. Population with a longer age range from the reservoir HS No. 3 did not have high linear growth rates, but its growth efficiency was higher. In this case, it is obvious that any assessment of growth will be relative and depend on the goals set for it. In the reservoirs of the canal there are more or less similar conditions for tench populations living due to the specifics of its functioning. The main limiting factor for the growth rate, in our opinion, will be abundance of the species in the reservoir and related trophic factors with a certain influence of withdrawal (fishing, predators).


2020 ◽  
Vol 18 (2) ◽  
pp. 23-32
Author(s):  
Andriy Pylypenko ◽  
Iegor Iermachenko

In the context of the sectoral policy of Ukraine’s economic development, experts identify the IT sector as one of the drivers of economic growth. The sector is characterized by higher than the global aver¬age economic growth rates, growth rates of tax deductions to local and state budgets, and growing growth rates in the share of exports in the overall structure of Ukraine’s exports. It was revealed that, along with positive trends, the development model of the IT sector in Ukraine remains extremely vulnerable to external “shocks”, since about 98% of orders are generated from the external market. In addition, outsourcing rather than product specialization is inherent in the IT sector of Ukraine. And in this case, the level of operational and financial efficiency, as shown by global statistics, is the lowest. This model of development of the IT sector is due to the low level of competitiveness of IT companies, a decrease in competitiveness in the global market, which necessitates the development of adequate mechanisms for managing the competitiveness of companies in the Ukrainian IT sector. The mechanism of forming an adaptive strategy in cognitive management of IT companies’ competitiveness is offered. This mechanism, in contrast to the existing ones, takes into account the contour of anticipation (warning), which allows determining the stability of competitive positions of companies in Ukraine’s IT sector and developing a proactive adaptive strategy aimed at maintaining a high level of competitiveness of IT companies in both local and global markets, increasing their business value. The blocks structure of the mechanism, the range of problems of each block and methods of their solution are determined.


2020 ◽  
Vol 10 ◽  
pp. 7-14
Author(s):  
Alena Aleksandrovna Vasilieva ◽  
◽  
Alexander Fedoseevich Borisov ◽  
Diana Anatolievna Narozhnaia ◽  
Ivan Vladimirovich Kyrtyak ◽  
...  

The article deals with a study of the destructive motivation of public servants on the example of the Republic of Sakha (Yakutia). The study was conducted from 2015 to 2018. The purpose of study was to determine what factors are demotivating for civil servants. The research method was the questionnaire method based on a stratified quota sample. It has been proven that this type of motivation in governmental bodies is primarily caused by the employees’ disappointment in expectations. Public service is attractive mainly due to the stability of employment and the high social status of an official. However, public servants have to deal with a lack of real power, a high level of stress, and work intensity. Also, the respondents consider their income as inadequate to their work and social status. As a result, employees tend to minimize their labor costs, and destructive motivation appears. The practice of personnel management applies several measures to eliminate this phenomenon, but not all of them can be implemented for the public service. The authors regard the following means as the most effective ones, namely: the improvement of labor organization, the automatization of routine operations, personal responsibility increase, and the development of decision-making discretion.


2020 ◽  
Vol 8 (8) ◽  
pp. 1476-1496
Author(s):  
V.V. Smirnov

Subject. The article discusses Russia’s economy and analyzes its effectiveness. Objectives. The study attempts to determine to what extent Russia’s economy is effective. Methods. The study is based on the systems approach and the statistical analysis. Results. I discovered significant fluctuations of the structural balance due to changing growth rates of the total gross national debt denominated in the national currency, and the stability of growth rates of governmental revenue. Changes in the RUB exchange rate and an additional growth in GDP are the main stabilizers of the structural balance, as they depend on hydrocarbon export. As a result of the analysis of cash flows, I found that the exports slowed down. Financial resources are strongly centralized, since Moscow and the Moscow Oblast are incrementing their share in the export of mineral resources, oil and refining products and import of electrical machines and equipment. Conclusions and Relevance. The fact that the Russian economy has been effectively organized is proved with the centralization of the economic power and the limits through the cross-regional corporation, such as Moscow and the Moscow Oblast, which is resilient to any regional difficulties ensuring the economic growth and sustainable development. The findings would be valuable for the political and economic community to outline and substantiate actions to keep rates of the economic growth and sustainable development of the Russian economy.


2020 ◽  
Vol 8 (3) ◽  
pp. 74-78
Author(s):  
Farrux Zulfiyev ◽  

This article is based on the principles of shared financing of the production of raw materials. The article is aimed at financing the production of capital on the basis of equity in order to further strengthen the stability of economic reforms in the republic. At the same time, the essence of equity financing, the risks associated with it, and the efficiency of raw materials are covered


Author(s):  
N.A. Jurk ◽  

The article presents scientific research in the field of statistical controllability of the food production process using the example of bakery products for a certain time interval using statistical methods of quality management. During quality control of finished products, defects in bakery products were identified, while the initial data were recorded in the developed form of a checklist for registering defects. It has been established that the most common defect is packaging leakage. For the subsequent statistical assessment of the stability of the production process and further analysis of the causes of the identified defect, a Shewhart control chart (p-card by an alternative feature) was used, which allows you to control the quality of manufactured products by the number of defects detected. Analyzing the control chart, it was concluded that studied process is conditionally stable, and the emerging defects are random. At the last stage of the research, the Ishikawa causal diagram was used, developed using the 6M mnemonic technique, in order to identify the most significant causes that affect the occurrence of the considered defect in bakery products. A more detailed study will allow the enterprise to produce food products that meet the established requirements.


2003 ◽  
Vol 792 ◽  
Author(s):  
V. Aubin ◽  
D. Caurant ◽  
D. Gourier ◽  
N. Baffier ◽  
S. Esnouf ◽  
...  

ABSTRACTProgress on separating the long-lived fission products from the high level radioactive liquid waste (HLW) has led to the development of specific host matrices, notably for the immobilization of cesium. Hollandite (nominally BaAl2Ti6O16), one of the main phases constituting Synroc, receives renewed interest as specific Cs-host wasteform. The radioactive cesium isotopes consist of short-lived Cs and Cs of high activities and Cs with long lifetime, all decaying according to Cs+→Ba2++e- (β) + γ. Therefore, Cs-host forms must be both heat and (β,γ)-radiation resistant. The purpose of this study is to estimate the stability of single phase hollandite under external β and γ radiation, simulating the decay of Cs. A hollandite ceramic of simple composition (Ba1.16Al2.32Ti5.68O16) was essentially irradiated by 1 and 2.5 MeV electrons with different fluences to simulate the β particles emitted by cesium. The generation of point defects was then followed by Electron Paramagnetic Resonance (EPR). All these electron irradiations generated defects of the same nature (oxygen centers and Ti3+ ions) but in different proportions varying with electron energy and fluence. The annealing of irradiated samples lead to the disappearance of the latter defects but gave rise to two other types of defects (aggregates of light elements and titanyl ions). It is necessary to heat at relatively high temperature (T=800°C) to recover an EPR spectrum similar to that of the pristine material. The stability of hollandite phase under radioactive cesium irradiation during the waste storage is discussed.


Mathematics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 78
Author(s):  
Haifa Bin Jebreen ◽  
Fairouz Tchier

Herein, an efficient algorithm is proposed to solve a one-dimensional hyperbolic partial differential equation. To reach an approximate solution, we employ the θ-weighted scheme to discretize the time interval into a finite number of time steps. In each step, we have a linear ordinary differential equation. Applying the Galerkin method based on interpolating scaling functions, we can solve this ODE. Therefore, in each time step, the solution can be found as a continuous function. Stability, consistency, and convergence of the proposed method are investigated. Several numerical examples are devoted to show the accuracy and efficiency of the method and guarantee the validity of the stability, consistency, and convergence analysis.


Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 63 ◽  
Author(s):  
Thomas Meunier ◽  
Claire Ménesguen ◽  
Xavier Carton ◽  
Sylvie Le Gentil ◽  
Richard Schopp

The stability properties of a vortex lens are studied in the quasi geostrophic (QG) framework using the generalized stability theory. Optimal perturbations are obtained using a tangent linear QG model and its adjoint. Their fine-scale spatial structures are studied in details. Growth rates of optimal perturbations are shown to be extremely sensitive to the time interval of optimization: The most unstable perturbations are found for time intervals of about 3 days, while the growth rates continuously decrease towards the most unstable normal mode, which is reached after about 170 days. The horizontal structure of the optimal perturbations consists of an intense counter-shear spiralling. It is also extremely sensitive to time interval: for short time intervals, the optimal perturbations are made of a broad spectrum of high azimuthal wave numbers. As the time interval increases, only low azimuthal wave numbers are found. The vertical structures of optimal perturbations exhibit strong layering associated with high vertical wave numbers whatever the time interval. However, the latter parameter plays an important role in the width of the vertical spectrum of the perturbation: short time interval perturbations have a narrow vertical spectrum while long time interval perturbations show a broad range of vertical scales. Optimal perturbations were set as initial perturbations of the vortex lens in a fully non linear QG model. It appears that for short time intervals, the perturbations decay after an initial transient growth, while for longer time intervals, the optimal perturbation keeps on growing, quickly leading to a non-linear regime or exciting lower azimuthal modes, consistent with normal mode instability. Very long time intervals simply behave like the most unstable normal mode. The possible impact of optimal perturbations on layering is also discussed.


Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1447
Author(s):  
Jose P. Suárez ◽  
Agustín Trujillo ◽  
Tania Moreno

Showing whether the longest-edge (LE) bisection of tetrahedra meshes degenerates the stability condition or not is still an open problem. Some reasons, in part, are due to the cost for achieving the computation of similarity classes of millions of tetrahedra. We prove the existence of tetrahedra where the LE bisection introduces, at most, 37 similarity classes. This family of new tetrahedra was roughly pointed out by Adler in 1983. However, as far as we know, there has been no evidence confirming its existence. We also introduce a new data structure and algorithm for computing the number of similarity tetrahedral classes based on integer arithmetic, storing only the square of edges. The algorithm lets us perform compact and efficient high-level similarity class computations with a cost that is only dependent on the number of similarity classes.


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