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This paper presents the results of bed scouring near an abutment that spans the entire floodplain width and terminates at the edge of the main channel, termed here as the bankline abutment. The cross section can be divided into a scoured section and an un-scoured section. The scoured bed profile can be approximated using a power function. An analytical method has been suggested to predict the maximum scour depth at bankline abutment. This method is valid irrespective of whether the original bed is at or below the threshold condition of sediment motion. The proposed method is consistent with the experiments from this study and previous studies. [ABSTRACT FROM AUTHOR]

The proposition of a diversified dispute resolution mechanism is mainly to realize the reasonable diversion of cases and promote the substantive resolution of disputes. Under this framework, all dispute resolution mechanisms must strictly follow the basic judicial principles and norms and abide by the bottom line of justice in the subjects and procedure of "dispute resolution" in order to gain the trust of the concerned parties. It is necessary to fully activate and give full play to their own characteristics and advantages and carry out the equal and orderly competition in the "diversified mechanism" to ensure that the concerned parties' right of free choice can be substantially expanded. As one of the components of the "diversified dispute resolution mechanism," the administrative reconsideration system should have the dual aspects of judicialization and administerization. The two aspects are not in a diametric opposition or tradeoff relation, but rather, they merely differ in observation perspectives, zone of action and specific direction to such an extent without compromising their coexistence and reciprocal promotion. Only by the judicalization and administerization of the administrative reconsideration system can we get it out of the current dilemma and gradually turn it into the main channel to solve administrative disputes. [ABSTRACT FROM AUTHOR]

Purpose: to analyze the issues of development and application of an automatic control system for the technological process of water distribution in the Donskoy main channel (DMC) using proportional-integral differential PID controllers and a control scheme for the upstream. The urgency of this purpose is justified by the fact that effective management of water level in channel is of great importance for agricultural production and water supply to adjacent territories. The analysis of the main components of the control system, including PID controllers and the upstream control scheme is performed. The possibility of using these components for effective control and regulation of water level in the channel is considered. Materials and methods. A detailed analysis of the factors that must be taken into account when designing an automatic control system of water in a channel using PID controllers has been carried out. An algorithm for controlling water level in the upstream channel using PID controllers is proposed. Results. Measures for the water distribution management system development and implementation in the Donskoy main channel are proposed. It is stated that when designing a control system, the configuration of the channel and the measures to ensure a uniform distribution of water along its entire length should be taken into account, considering the unsteady water motion in the Donskoy main channel. The results of the analysis show that the automatic control system using PID controllers and the upstream control scheme has the potential to control the water level in the DMC effectively. Conclusions. Based on the analysis carried out, it was concluded that it is possible to design an automatic water control system in the DMC using PID controllers and a control scheme for the upstream successfully. Further research and development can contribute to the optimization of water distribution management and increase the efficiency of agricultural production in the region.

A tidal channel will be affected by the intrusion of seawater, so the current and water depth in the channel will change at every moment. These changes are critical to the hydrodynamic characteristics of water intakes in tidal rivers. This paper establishes a 3D model and validates it through laboratory models, then analyzes the influences of dynamic change of flow velocity and water depth, and the amplitude changes of velocity and water depth on the secondary flow in the water withdrawal process. With the increase of the main flow velocity and the decrease of the water depth, diversion width at the water intake decreases, the peak velocity increases, and the intensity of the secondary flow also increases. With the increase of the velocity of the main channel and the changing rate in water depth, the lag time of the velocity change at the water intake is also longer, and the peak velocity will be greater than the velocity of the constant flow. The influence of the water depth change is greater than that of the main channel velocity change. Combining these four factors, more sand may be washed into the inlet channel under conditions of high flow and low water depth. HIGHLIGHTS Hydrodynamic change rule of intake when the water level of main river changes dynamically.; Hydrodynamic change rule of intake when the velocity of main river changes dynamically.; Time lag law of hydrodynamic change of water intake with the water level change of main river.; Time lag law of hydrodynamic change of water intake with the velocity change of main river.; Optimal water intake combination for tidal channels.;

This paper presents the results of bed scouring near an abutment that spans the entire floodplain width and terminates at the edge of the main channel, termed here as the bankline abutment. The cross section can be divided into a scoured section and an un-scoured section. The scoured bed profile can be approximated using a power function. An analytical method has been suggested to predict the maximum scour depth at bankline abutment. This method is valid irrespective of whether the original bed is at or below the threshold condition of sediment motion. The proposed method is consistent with the experiments from this study and previous studies.

The present research aimed to demonstrate the feasibility of using image segmentation for better drainage extraction, automated drainage network hierarchization and main channel definition based on Horton (1945). The test area for the applications was the Bandeirinha Stream Hydrographic Basin (BSHB), which is located in the municipality of Formosa, in the state of Goiás, Brazil. The study used the Shuttle Radar Topography Mission (SRTM), with a spatial resolution of 1" x 1" (one arc second). The SRTM segmentation was performed using the Python language ODR_Obia algorithm, inserted with a QGIS plugin. Through the QGIS platform, the ODR_Hidro plugin was used to perform the delimitation of the BSHB, the extraction of the drainages and the definition of the main channel. The results were validated in the field and evaluated from the manual definition of the main channel. That was done using both the data produced by the application and the drainage data contained in the vector base of the topographic maps of the Army of Geographic Service (AGS), at the scale of 1:100,000 and 1:25,000. From the results obtained, it can be inferred that the ODR_Hidro model used for the delimitation of the BSHB, the automated hierarchization of the drainages and the definition of the main channel from the segmented SRTM image is very efficient. The field validation demonstrated its effectiveness by proving the existence of first-order drainages which are not mapped on the DSG chart at a scale of 1:100.000. This leads to the conclusion that the use of the proposed tools and the inclusion of image segmentation, aiming for the extraction of drainage network and geomorphometric characterization of watersheds, can efficiently contribute to the provision of morphometric data. [ABSTRACT FROM AUTHOR]

This study focuses on relatively understudied coastal systems – non-tidal inlets along a barrier coast. We describe the morphological elements of these inlets (prorvas) along the northern coast of the Black Sea using an example of the Tendra-Dzharylgach barrier (TDB) system, Ukraine. Channels vary from 15 m to >700 m in width, with relatively shallow depths of 1.0–1.5 m (rarely >3 m). This is a first comprehensive overview of TDB breaches and their evolution as inlets, with dynamic relationships between the channel and its associated depositional elements (frontal and bay-side deltas). Comparisons are made with the analogs of the latter along tide-influenced coasts: ebb- and flood-tidal deltas, respectively. The region of interest is subject to the effects of both rapid geomorphological change and ongoing military conflict, making this field dataset of great relevance in complementing other remote sensing databases at nearby sites. • Describes relatively unstudied coastal systems – non-tidal inlets . • Unique dataset that uses field data in a region now under military occupation. • Recent storm impact highlights importance of ongoing research. [ABSTRACT FROM AUTHOR]

In a radial bed, the uniformity of the pressure drop distribution is investigated by Euler single-phase flow and porous media models under different operating mode (CF-U/Z, CP-U/Z), gas flow rate (120–240 m3/h), particle diameter ((0.5–3)exp-3 m) and bed voidage (0.3–0.6). According to the nonuniform index η, the uniformity relates to these parameters and improves with increasing total pressure drop of particle bed Δps (sum of the pressure drops of particle bed and gas perforation) or decreasing main channel pressure drop Δpg. Comparing the flow fields with/without particles, Δps is approximately equal to the pressure drop of the particle bed with high-porosity Johnson net, which is well calculated by the Ergun equation. Δpg can be calculated by the modified momentum equation containing k. After changing the wall shear stress and gas-solid axial resistance, it is found that the internal generation factors for k include the influence of gas perforation on boundary layer and the existence of gas axial velocity after perforation. Besides, the global/local k hardly changes with the investigated parameters. The local k is a function of axial position or velocity ratio, which changes obviously at the end of the main channel for the existence of a gas stagnation zone. [ABSTRACT FROM AUTHOR]

The sediment deposited by the external flood into the main channel will weaken the flow capacity of the channel, causing the water body to overflow the top and overflow the embankment, which will seriously affect the stability of the embankment slope. The effects of sediment concentration in external flood on the transverse and vertical distribution of flow velocity, sedimentation process and sedimentation morphology in the main channel were studied by physical model test. The results show that the middle of the main channel is less affected by the external flood and the resistance of the channel side wall, and the flow velocity is larger. On the contrary, the flow velocity near the flood mouth and the channel side wall is smaller. The flow velocity increases with the decrease of water depth in a certain depth range, and decreases when it is near the surface. With the increase of external flood sediment concentration, the sediment deposition thickness increases, and the initial position of sediment deposition and the maximum position of sediment deposition thickness are closer to the upstream of the main channel. [ABSTRACT FROM AUTHOR]

Branching channel flow describes any side water withdrawals from rivers or main channels. Branching channels have widespread application in many practical projects, such as irrigation and drainage network systems, water and waste-water treatment plants, and many water resources projects. Therefore, in this research, a comprehensive analysis of laboratory data has been carried out to discover the best angle of branching. The study also aims to introduce simple, practical equations to help engineers of water resources to fix the percentage of discharge diverted to the branch channel. The study was carried out in the Irrigation and hydraulics laboratory of the civil department, Faculty of Engineering, Assiut University. The laboratory channel consisted of two parts, the main channel, and a branch channel. The main channel was 8.0 m in length, 20 cm wide, and 20 cm in depth. The division corner to the branch channel was sharp edged and located 5.0 m downstream of the main channel inlet. The branch channel was 3.0 m long, 20 cm in depth and its width was changed three times (10, 15, and 20 cm) respectively. A total of 84 runs were carried out. Investigations of the flow into the branching channel show that the branching discharge depends on many interlinked parameters. It increases with a decrease of the main channel flow velocity and the Froude number upstream of the branch channel junction. It also increases with an increase in the Yb / Yu ratio. In subcritical flow, water depth in the branch channel is always lower than the main channel water depth. The flow diversion to the branch channel leads to a decrease in water depth downstream of the main channel. In addition, the study showed that the highest discharge rate was obtained when the angle of branching was equal to 45° and then an angle of 60o. While the lowest discharge rate was obtained at an angle of 90°. Furthermore, at Br = 1.0, using a branching angle equal to 45° the discharge ratio (Qr) increases from about 4.42 to 19.01%, more than that obtained with using the branching angle equal 90°, while the discharge ratio (Qr) increases from about 0.52 to 49.18% and 1.51 to 24.79%, at Br = 0.75, and Br = 0.5 respectively.

Catalase has crucial role in adaptive response to H2O2. Main channel structure responsible for substrate selectivity was estimated to understand the relationship between the evolutionary direction of catalases from Exiguobacterium oxidotolerans and Psychrobacter piscatorii which survive in cold and high concentration of hydrogen peroxide, and their catalytic property. E. oxidotolerans catalase (EKTA) exhibited a higher ratio of compound I formation rate using peracetic acid (a substrate lager than H2O2)/catalase activity using H2O2 as the substrate than P. piscatori catalase (PKTA). It was considered that the ratio was attributed to the size of the amino acid residues locating at the bottle neck structure in the main channel. The differences in the ratio of the compound I formation rate with peracetic acid to catalase activity with H2O2 between the deeper branches in the phylogenetic tree in both EKTA and PKTA were large. This indicates that catalases from the hydrogen peroxide-tolerant bacteria have evolved in different directions, exhibiting effective catalytic activity and allowing broader substrates size or H2O2-specific substrate acceptability in EKTA and PKTA, respectively. It is considered that the main channel structure reflected the difference in the evolutionary direction of clade 1 and clade 3 catalases. [ABSTRACT FROM AUTHOR]

• A new stage ∼ discharge relation for two stage wide sinuous channels is presented. • The new method is validated with a number of small and large scale laboratory data. • The method is applicable for 5.5 < width ratio = 30 & 1.1 < Sinuosity < 2.54. • The method is suitable for homogeneously smooth and non homogeneously rough cases. • The method is found very satisfactory when compared with other well known methods. • It is quite simple to apply because of lesser empirical constants /coefficients. A new stage discharge relationship is suggested for wide meandering streams (ratio of floodplain width and that of main channel in excess of 5.5 and up to 30) with overbank flow. The boundary shear data obtained from various data series with specified range of width ratio and channel sinuosity are analysed. By regression technique, new empirical relationships are derived between the channel dimensions and amount of shear generated for different flow conditions. These new boundary shear models are then used to obtain the stage discharge relation in channels with given roughness characteristics. The present method is then validated for its usefulness by applying the same to a number of data series of small scale and large scale flume experiments of other research projects from the literature. The errors (%) in discharge estimation are within limits for such methods as per practice (i.e. around ±10% for both smooth and rough meandering channels). The method is also compared with a number of other methods from the literature by application to different data series. The RMSE (root mean squared error) value for all the data series validated is estimated as 9.6% and the method is found to be ranked third among all the methods. The method is also able to predict satisfactorily the flow distribution in case of a number of homogeneously smooth and non homogeneously roughened meandering channels of varying sinuosity with overbank flow for large scale flume experimental data sets. The mean error for three available data series is estimated as −3.4% while the RMSE error is 10.68%. Due to its ease of application and simple approach, this 1D method may serve as a preliminary design tool for assessing stage discharge curve for wide two stage channels in field conditions for application in flood estimation and flood warning cum relief measures. Such a preliminary study might better decide the need for further refinement through any exhaustive deep study; the more robust and expensive 2D or 3D analysis. [ABSTRACT FROM AUTHOR]

In this paper, we consider an independent and identically distributed Nakagami- fading single-input multiple-output (SIMO) channel, where the transmitter sends some confidential message to the legitimate receiver in the presence of an eavesdropper. Both the receiver and the eavesdropper have multiple antennas. We formulated the probability of non-zero secrecy mutual information, secure outage probability, and ergodic secrecy mutual information for the SIMO wireless communication system. The calculations have been carried out using small limit argument approximation on zeroth-order modified Bessel function of first kind. This approximation provides decent results in the low signal-to-noise-ratio (SNR) regime. In the low-SNR regime, either the transmission power is small or the bandwidth is large. In either case, it is difficult for an eavesdropper to detect the signals in this regime. We present that in the presence of fading, positive secrecy mutual information is achievable even when the eavesdropper has better SNR than the main channel. We also found in our work that at low-SNR regime, the effect of number of eavesdropper's channel on average secrecy mutual information is almost negligible. [ABSTRACT FROM AUTHOR]

The liquid-liquid extraction method has been one of the most critical chemical engineering processes for many years. The combination of liquid-liquid extraction and microfluidic systems constitutes a significant advancement in this process in recent years. The inherent advantages of microfluidic systems, due to their micro dimensions and the widespread application of liquid-liquid extraction, have made this process more applicable in various industries. This article focuses on microfluidic systems, discussing the effects of changes and modifications made to the main channel of these systems, as well as the resulting improvements in flow type and channel shape, and their applications. The assessment concludes with a discussion of the prospects of this field. [ABSTRACT FROM AUTHOR]

Mapping the route of nucleoside triphosphate (NTP) entry into the sequestered active site of RNA polymerase (RNAP) has major implications for elucidating the complete nucleotide addition cycle. Constituting a dichotomy that remains to be resolved, two alternatives, direct NTP delivery via the secondary channel (CH2) or selection to downstream sites in the main channel (CH1) prior to catalysis, have been proposed. In this study, accelerated molecular dynamics simulations of freely diffusing NTPs about RNAPII were applied to refine the CH2 model and uncover atomic details on the CH1 model that previously lacked a persuasive structural framework to illustrate its mechanism of action. Diffusion and binding of NTPs to downstream DNA, and the transfer of a preselected NTP to the active site, are simulated for the first time. All-atom simulations further support that CH1 loading is transcription factor IIF (TFIIF) dependent and impacts catalytic isomerization. Altogether, the alternative nucleotide loading systems may allow distinct transcriptional landscapes to be expressed.

Due to momentum exchange between main channel and floodplains, the flow hydraulics in compound channels is taken into account as a comparatively complicated system. Most studies in this research fields are focused on the prediction of cross-sectional average velocity and total flow discharge. In quite a few situations, however, the subsection or individual flow discharges are imperative rather than the total discharge. For instance, in flood conditions and in the case of spill of water on the floodplains, the bed and suspended sediment loads are inevitably transported by the main channel flow discharge. In current investigation, using laboratory stage–discharge datasets from canals with compound channel sections, the individual flow discharges in the main channel and over floodplains are predicted applying gene-expression programming (GEP), model tree (MT) and evolutionary polynomial regression (EPR), and then compared with traditional divided channel methods. Results showed that the proposed soft computing methods have promising performance in the prediction of subsection flow discharges for both main channel and floodplains. EPR provided the flow discharge in main channel and floodplains with more efficient performance compared to the GEP and MT models. Furthermore, among the traditional methods, the diagonal and vertical divided channel methods with mean errors of 11% and 19% have the greatest and lowest precision in estimation of main channel discharge, respectively. Conversely, over the floodplains the vertical and horizontal divided channel methods estimated the flow discharge with mean errors of 6.8% and 247% as the best and worst models in terms of efficiency, respectively. [ABSTRACT FROM PUBLISHER]