The Influence of Intra-Day Non-Uniformity of Operation of Large Hydroelectric Powerplants on the Performance Stability of Water Intakes Located in Their Upper Pools

The creation of reservoirs in water streams leads to significant changes in the hydrological regime of water bodies: it allows smoothing the peaks of maximum water discharge during a flood period and regulating low-water flow. The creation of reservoirs with significant storage capacity makes it possible to solve a wide range of water-management problems, including the use of falling water energy for hydropower purposes, and maintenance of the uninterrupted water supply and navigation. Since constructed dams are usually operated by hydropower companies, the regulatory regime for the discharge of water into the lower pool is often determined by the daily electricity consumption regime. Intra-day variations in the volume of water discharges through hydroelectric power stations generate multidirectional streams in the upper pool, which can affect the operation of other water withdrawal systems. This paper considers the effect of intraday variations in water discharges into the lower pool on the dynamic and physical properties of the water mass in the region of the location of drinking water-intake heads of Perm city and the quality of the withdrawn water.

Environmental and hydrological risks in the Lake Baikal basin water resources management

For optimal water resources management of the Angara reservoirs cascade (a complex “Lake Baikal – Irkutsk, Bratsk, Ust-Ilimsk and Boguchansk reservoirs”) and water users provision in the MIKE 11 software a quasi-two-dimensional simulation hydrodynamic model of the Angara hydroelectric power stations (HPS) cascade from Lake Baikal to the Boguchansk HPS downstream, which is a tool for reproducing the features of the water flow hydrodynamic structure, was developed. A hydrodynamic computer model using the built-in module “Regulating structures” module makes it possible to form reasonable operating modes of the Angarsk cascade of reservoirs that meet the most significant requirements of water users: ecology, fisheries and utilities, transport and energy. Hydrodynamic calculations and the flood zones obtained in the GIS project of the territory showed that catastrophic phenomena in the floodplain and coastal zone of Irkutsk occur even when releases into the lower pool of the Irkutsk reservoir exceed 3200 m3/s. The developed hydrodynamic model of the Angarsk cascade of reservoirs makes it possible to determine the objects and floodplain areas most susceptible to flooding in the downstream of the Irkutsk HPS for further development of scientifically based measures to protect them, prevent flooding and develop evacuation plans in an emergency.

A procedure to forecast and manage water resources and to redistribute runoff water flow when passing floods

Economic losses from floods have become catastrophic due to the increase in the number and scale of their propagation. Existing procedures for passing floods and pre-preparing reservoirs for flood water acceptance are ineffective and need to be improved. Therefore, the task to devise a methodology that would eliminate these shortcomings was urgent. This paper has proposed a procedure for calculating the passage of floods based on the forecasts of water inflow, taking into consideration the characteristics of the flood wave and the mode of reservoir filling, which makes it possible to bring down (reduce) the maximum flow rate through a waterworks by accumulating floodwaters in the reservoir. The software package Mike 11 (Danish Institute, Denmark) was employed to build a hydrodynamic model of floodwater movement along the examined river section from a hydrological station to a waterworks, which makes it possible to determine the levels of water and the flow rate in a reservoir at any time in the form of free surface curves when passing floods of various range. Based on the devised methodology, recommendations have been compiled for the forced discharges of water through hydroelectric turbines (in m3/s) when passing floods of various probabilities (which is especially important for floods whose probability is 0.01 %). The constructed hydrodynamic model of floodwater movement through a reservoir has allowed the verification of the devised procedure. The procedure was devised in order to effectively pass floodwaters and bring down the maximum flow rate through a waterworks. The introduction of the methodology for calculating the passage of floods could make it possible to avoid idle water discharge through the water drains of waterworks to the lower pool and provide for the most efficient utilization of floodwater resources

An In Vitro Nerve Agent Brain Poisoning Transwell Model for Convenient and Accurate Antidote and Nanomedicine Evaluation

Background: Nerve agents (NAs) can irreversibly inhibit acetylcholinesterase (AChE). An effective NA antidote should permeate the blood–brain barrier (BBB) to reactivate the inhibited AChE in brain. There is an urgent requirement for the large-scale evaluation and screening of antidotes. Existing methods for evaluating reactivators in vitro can only examine the reactivation effect of drugs and not brain-target properties. The current Transwell BBB model can only evaluate the drug penetration performance for crossing the barrier, but not the pharmacodynamics. Methods: Highly purified rat brain microvascular endothelial cells (RBMECs) from 2-week-old Sprague Dawley rats were inoculated into the upper chamber of Transwell plates to establish a BBB model. Three key parameters of AChE reactivation were determined by the Ellman method: the minimum detection limit of AChE, the effective dosage of NAs (70% enzyme inhibition rate), and the optimal dosage of reactivators. AChE and NAs were added to the lower pool of Transwell plates to simulate central poisoning, and antidotes of reactivators were added to the upper pool to simulate drug administration. The AChE activity of samples, collected from the lower pool, was measured. A liposomal nanomedicine loaded with the reactivator asoxime chloride (HI-6) was prepared using the extraction method and tested by the model.Results: The obtained RBMECs exhibited a typical monolayer “paving stone” morphology, and tight junctions were expressed among the RBMECs. The concentrations of AChE, sarin, and the reactivator were 0.07 mg/mL, 10–6 v/v, and 0.03 mg/mL, respectively. The reaction rate of the reactivators obtained from the model was significantly lower than that obtained from the non-model group. Furthermore, a nanomedicine loaded with HI-6 was synthesized. The final results and rules obtained from the model were in accordance with those evaluated in vivo. Conclusion: The therapeutic effect of antidotes can be rapidly and accurately evaluated using this model. In addition to small-molecule drugs, nanomedicines can also be evaluated by this method. A liposomal nanomedicine with a high reactivation rate against the nerve agent sarin was discovered.

The analysis of the channel deformations in the lower pool of the Votkinsk reservoir

The sand and gravel mix is mined at the Votkinsk reservoir. This leads to horizontal and vertical channel deformations. To study them, we examined the Golyanovsk section of the sand and gravel mix (SAGM) field in the lower pool of the reservoir. We used the channel surveys made in 2012-2016, 2018 and 2019 as the source of cartographic materials. The lower pool section of the Votkinsk hydroelectric complex, within which the Golyanovsk SAGM field is located, is characterized by a fully regulated effluent and an unsteady hydrological regime. Therefore, the hydrological regime of the considered area is particularly complex and depends on the water consumption in the alignment of the Votkinsk hydroelectric station and the level of the Nizhnekamsk reservoir. The average long-term water discharge for the navigation period is 2200 m3/s, the average long-term minimum monthly discharge rate is 1800 m3/s. The field survey of the area was carried out during the low water period in accordance. This period was characterized by minimum levels at around 64.79-65.24 m BS. The water discharge varied between 1720-1780 m3/s. With this flow, the Kama River is characterized by fairly low flow speed: no more than 1.29 m/s on the rod and 0.2-0.5 m/s on the riverbank shallows. The channel deposits are represented by pebble-gravel soils of various sizes. Throughout 2001-2019 an increase in the particle size has occurred. This is due to the change of the channel-forming process from accumulation to erosion. Horizontal deformations are represented by the reformation of the riverbanks, vertical – by accumulation and erosion of bottom. Drawdown levels are the result of natural deformations of the channel. According to the monitoring data, the duration of the “drawdown – growth” cycle is 2-3 years. The duration of the “drawdown – growth” cycle is 2-3 years.

Flow kinematics with oppositely rotating coaxial layers

In modern technological processes, liquid and gas flows play an important role. This is especially mostly evident in hydraulic engineering and hydropower construction when designing the highly efficient hydraulic turbines, various spillway systems and other elements of layout patterns of structures. When designing and constructing such facilities, it is necessary to know the characteristics of the flows to be passed through these structures in order to correctly take into account the various types of impacts from the flow: pressure pulsations, cavitation and erosion due to cavitation, wave formation and abrasive wear. When designing high-head spillway structures, special attention is paid to the presence of excess energy from the stream entering the lower pool, which requires special measures to dissipate it. Nowadays, in the practice of construction of hydraulic structures, swirled flows are used including those with oppositely rotating layers. This type of flow creates a number of effects that allow one to radically solve the problems of energy dissipation of high-velocity flows. The report presents the results of studies of a complicated flow formed by oppositely rotating coaxially arranged layers of liquid made by a physical method. The description of the experimental stand for the model studies of such flows is given. The basic parameters of the installation, the principle of operation of the recording equipment and its main characteristics are given. The results of model studies in the form of distribution of the components of the flow velocity along the cross section of the flow conductor and its length are given.