For the Volga River, studies of interannual changes in water discharges in the period 1958-2021 were carried out. Systematic hydrological observations were carried out at the Zhiguli hydroelectric ...complex on the border of the Middle and Lower Volga. 97% of the water runoff of the entire Volga is regulated in this section in the seasonal, weekly and daily range. It was found that the average water flow was 7704 m3/s. The amplitude of interannual fluctuations was 5270-10431 m3/s. Temporal changes in the average annual water discharges were characterized by cyclicity, including the change of low-water and high-water phases. From 1958-1975 a low-water phase was observed, from 1976-1996 - high-water and since 1997-2021 - again shallow. A comparison of the historical (1877-1955) and modern (1958-2021) periods showed that over 144 years, the average water flow of the Volga River has not changed much. However, as a result of the regulation of water flow in the period 1958-2021 the value of water discharges in high-water years decreased, while in low-water years it increased.
In mountain areas, one of the noticeable results of modern climate change is rapid shift of treelines to subalpine and alpine meadows. Such vegetation shifts is associated with a change in quality of ...the plant residues entering the soils, which in turn can affect the mineralization activity (basal respiration) and functional diversity of the soil microbial community. Therefore, the study was aimed at assessing the soil microbial (basal respiration and functional diversity) and chemical (C, N, C/N, pH) properties (0-10 cm) along the reserved and grazed forest-meadow transects of the Northwestern Caucasus (Karachay-Cherkess Republic), as well as evaluating an effect of vegetation type and land use on variation of these soil properties. It was found that the C and N contents (for both land usees), pH and basal respiration (reserved slope) significantly increase from forest to meadow soils. In contrary, the microbial functional diversity decreased from forest to meadow soils, which might be due to less diverse organic compounds entering the soil only with grass residues than their combination with forest litter. Two-way ANOVA showed that soil microbial functional diversity, pH, C and N along the studied forest-meadow transects was mostly associated with vegetation type (1439 % of the explained variation), and C/N and basal respiration - with land use (3336 % of the explained variation). Thus, a land use change will have a more significant effect on the mineralization activity of soil microbial community than a treeline shifts.
Purpose
The paper presents a systematic literature review on business model transformation (BMT). The aim of the study is to determine the main research streams in BMT literature, develop a ...conceptual model on BMT research, and identify potential directions for future research.
Design/methodology/approach
The authors use systematic literature review approach and provide a detailed protocol to meet reliability requirements. The study is based on the multilayer in-depth analysis of 92 articles published in leading international journal in general management, international business, strategy, innovation, and organization studies.
Findings
The paper identifies a crucial importance of further research on BMT with regards to the context specificity of a company's country of origin, transformation of value delivery and value capture blocks of BMs, entrepreneurial techniques of BMT management, and international aspects of BMT.
Originality/value
By a means of systematic literature review, the paper envisages the current state of knowledge about BMT, traces the development of BMT research, classifies it, and identifies potential directions for future inquiries.
Goal: to identify strategic responses of large Russian companies running international activities to changes of situational factors in their external environment and subsequent transformation of ...their business models. Methodology: empirical basis of the article consists of primary data obtained through interviews conducted with representatives of large Russian corporations, and secondary data from open sources, corporate reports and media publications. Findings: the author formulated three assumptions that emphasize different business model blocks: the one with the highest competitive advantage concentration, the one with concentration of a company’s activities in the home market, and the one that is most subject to institutional changes. Contribution of the author: the study results form new approaches within the framework of institutional theory and represent a further step toward understanding a process of business model transformation of Russian companies under significant institutional changes.
The ecological state of the protected Islands Seredysh and Shalyga (now Bakhilovsky island) depends on the water content and flow of the Volga River. We have analyzed the long-term changes in the ...water flow of the Volga River for the period 1958-2017 in the alignment Zhiguli dam, located 12 km upstream from the island. According to the average annual water consumption, there are three periods that differ from each other in water content: low-water period (1958–1976), high-water period (1977–1997) and the period of average water content (1998–2017), with extremely low-water (1967, 1973, 1975, 1976, 1977, 1996) and extremely high-water (1966, 1979, 1981, 1990, 1991, 1994) years. In highwater years, during the passage of the spring flood, the island is almost completely flooded, and in low-water years, during the summer low water, the area of the island increases and changes its configuration.
Realization of self-healing polymer materials cannot rely on the wealth of active repair tools found in living systems but must focus entirely on the structural composition of the material and the ...properties of its constituents. Current challenges of the search for such compositions include healing of large-scale defects as well as the need for a healing process that is generated by the scission itself. Herein, we describe ionomer–rubber blends from poly(ethylene-co-methacrylic acid) and peroxide cross-linked ethylene–propylene–diene monomer (EPDM) that combine three types of cross-links: covalent links of a network of EPDM, clusters of aggregated ionic groups, and crystalline domains of longer ethylene sequences in the ionomer. Above the melting point of the latter, the components mix homogeneously, indicated by the clarity of the samples and supported by small-angle X-ray scattering (SAXS) and NMR. At ambient conditions, the samples are hard like a thermoplastic material. Self-healing after mechanical damage is enabled by two types of structural memory related to a hierarchy of deformation- and defect-caused stresses and their relaxation paths. Because of the solid-like character of the materials, damage-caused stress is retained by the micro deformation and rupture of the aggregates on small scales and on large scaleby the macroscopic shape memory effect of the deformed covalent network. When the samples get annealed at an elevated temperature, the former enables mending of fracture-caused surfaces and the lattershape recovery. Based on a careful evaluation of the structural relaxation effects on the blends and their constituents (differential scanning calorimetry, NMR, and wide-angle X-ray scattering/SAXS), we demonstrate the repair of defects in the range of millimeters to centimeters by the defect-caused stresses. It is intrinsic to our concept that it holds only to damages such as scratches, small cuts, and microcracks, whereby the object is not fully fragmented, and that it will require thermal activation.
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Mobile technology is developing quickly and becomming a part of daily life and communication. Bluetooth Low Energy is presented as a new way of mobile interaction. However there are not enough ...studies in this field on the interaction between mobile devices and the physical world. In order to understand user needs, and to encourage users to interact, we simulated an interaction process through designing and testing a prototype in a specific indoor environment. Prototype effectiveness and main characteristics for future mobile application was evaluated through a qualitative user study with 20 participants who interacted with our prototype.
Den mobila tekniken växer snabbt och blir en del av våra liv och vår kommunikation. BLE presenteras på ett nytt sätt inom mobilinteraktion. Det förekommer inte tillräckligt med studier inom området för interaktionen mellan mobila enheter och den fysiska världen. För att förstå användarbehov och få användare att interagera har vi simulerat en interaktiv process genom att designa och testa en prototyp i en specifik inomhusmiljö. Utvärdering av prototypens effektivitet och heuristiken har evaluerats genom en kvalitativ studie med 20 användare som har deltagit i interaktionen med vår prototyp.
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