Canal Cross-section Research Articles

Glycolic acid on push-out bond strength of fiber post and smear removal: an in vitro study.

This study aims to investigate glycolic acid (GA) as a final irrigant on push-out bond strength of fiber post and smear removal. Ninety mandibular premolars were stabilized with a silicone key and photographed, and canal cross-section was calculated by image processing software. Round canal morphology was selected. The specimens were divided into five groups (n = 18); 10%GA, 17%EDTA, NaOCl + 10%GA, NaOCl + 17%EDTA, and the control. Fifteen specimens were used for the push-out. Three specimens were evaluated using a scanning electron microscope after post space preparation. Two-way ANOVA and Chi-square were used for statistics. GA presented higher strength than EDTA (p < 0.05). The NaOCl + GA showed higher strength than the NaOCl + EDTA (p < 0.05). The highest values were observed in cervical and lowest in apical thirds (p < 0.05). The most failure type was between dentin and resin (p < 0.05). GA removed the smear in the post space including the apical third. The NaOCl + GA has superiority to NaOCl + EDTA on push-out strength. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA.

The Spatial Characteristics of Intervertebral Foramina within the L4/L5 and L5/S1 Motor Segments of the Spine

The prevalence of lower back pain and radicular pain in the population requires more and more accurate diagnostic methods to more effectively prevent and treat patients with these ailments. In this paper, we focused on one of the causes of lower back pain and radicular pain—lumbar foraminal stenosis (LFS). The aim of the study is to assess the morphometry of the intervertebral canals in the lumbar spine at the levels of the L4/L5 and L5/S1 motor segments. The obtained results showed correlations between the circumference and the surface area on individual cross-sections of the intervertebral canals at the L4/L5 and L5/S1 levels and determined the approximate shape of the root canal and its variability. On this basis, we were able to determine the influences of the patient’s age and sex on the morphometric parameters of the intervertebral canals at the L4/L5 and L5/S1 levels. Further research is needed in this area, taking into account additional factors influencing the shape of intervertebral canals.

ANALISA KAPASITAS KANAL PASSO KOTA AMBON MENGGUNAKAN HEC-RAS 5.03

Passo Village is a lowland area, where the Passo area has quite dense residential areas. . The increase in population growth and changes in land use that occur in the Passo Village area have resulted in many changes that will have negative impacts in the form of flooding or inundation. This is what happens in the Passo Village area, where during the high intensity rainy season there are often floods or puddles around the area. The existing canal system is not functioning properly. This is due to the narrowing of the Passo Canal channel due to the presence of buildings on the canal border such as residences and shops. The Passo Canal was used as a rubbish dump. The dimensions of the canal have changed and cannot accommodate the existing hydrological discharge. In overcoming this problem, the aim of this research is to determine the water level in the Passo Canal with the help of HEC-RAS 5.03 Software and to find out preventive methods for overcoming flooding problems in the Passo Canal. The initial stage is hydrological and hydraulic analysis. The results of the hydrological analysis are rainfall distribution using the Log Pearson III distribution, to calculate the planned discharge using the Der Weduwen method, it is obtained with a 10 year return period of 0.398 m3/sec. The results of hydraulic analysis using HEC-RAS 5.03 software showed that the highest water level at the S15 canal section was 0.52 meter. From this research it can be concluded that the Passo Canal requires flood management efforts, especially by normalizing the canal cross-section.

Assessing the morphological changes on the operation performance of canal: a case study of the Suez Irrigation Canal, Egypt

Abstract Morphological changes along the cross-section of canals affect the canal's performance to fulfill the desired operations. The Suez Irrigation Canal is a vital canal that provides the surrounding region with drinking water via about 21 drinking water treatment plants and serves about 140,000 feddan of irrigated land. However, the actual canal capacity is incapacitate to convey sufficient water for drinking and irrigation necessities. This research particularly evaluates the morphological changes in the Suez Canal's performance and increasing its ability to transport the required discharges with adequate operations. For this purpose, extensive field measurements and a numerical model (SOBEK 1D) were adapted to evaluate the canal capacity and operation under the required flow conditions. In total, 890 canal cross-sections were surveyed and 16-flow discharge measurements were considered to identify the actual geometric and hydraulic characteristics. The SOBEK 1D model was used to simulate different scenarios of canal cross-sections under changing flow conditions. The results showed that the actual canal mainly suffered from sedimentations that reduced the canal's capacity to transport the design flow discharges. In summary, rehabilitation of the canal is intensely recommended, in addition to the planned and sufficient clearance activatesof the canal to keep effective operations.

Applications of visualizing cochlear basal turn in cochlear implantation.

To report a reliable method in obtaining optimal cochlear basal turn and cross-section (c/s) of internal auditory canal (IAC) supporting Cochlear implantation (CI) procedure. Computer tomography (CT) and magnetic resonance image (MRI) scans of potential CI candidates from 2018 to 2022 from the tertiary center were considered for analysis. Slicer software was used in three-dimensional (3D) segmentation of inner ear and for capturing the cochlear basal turn. A total of 1932 head scans were made available for the analysis and out of which 1866 scans had normal anatomy (NA) inner ear. Incomplete partition (IP) type-I was identified in 19 ears, IP type-II in 27 ears, IP type-III in 6 ears, cochlear hypoplasia (CH) type-I in 6 ears, CH type-II in 1 ear, CH type-III in 3 ears, and CH type-IV is 3 ears, and enlarged vestibular aqueduct syndrome in 1 ear. 3D segmented inner ear helped in successfully obtaining the cochlear basal turn and the c/s of IAC in all anatomical types. Time taken to capture the cochlear basal turn with the help of 3D segmented inner ear was <1 min. Within the NA category, five cases showed scalar ossification, and its extent was identified in the cochlear basal turn. The identification and the extent of ossification in the scala tympani, shape of the basal turn, and the cochlear size measurement in cochlear basal turn has high clinical relevance as this helps in surgical planning and in choosing appropriate electrode length. Level of evidence: Level 2 to the best of our understanding.

Influence of the canal width and depth on the resistance of 750 DWT Perintis ship using CFD simulation

Investigation of hydrodynamic interaction between the vessel and the seabed when entering shallow water is considered one of the most critical considerations of inland waterway transport. There are many investigations into the behavior of ships in restricted waters, such as ships traveling in different forms of canal cross-sections. The present study aims to evaluate the hydrodynamic interaction of the 750 DWT Perintis Ship moving through the different canal types to determine the relative effects of limiting the width and depth cross section on the ship's resistance. Two different canals with different cross sections, including canal bank and rectangular canal, were evaluated to investigate the influence of canal width (Wb), depth ratio (hw/T), and blockage ratio function (As/Ac). The Computational Fluid Dynamic (CFD) method with Reynolds-averaged Navier–Stokes (RANS) solver and turbulent model 𝑘−𝜀 were used to predict the total resistance of the ship. The proposed numerical simulation was initially validated with an experimental towing tank test in the error range of 0.11-7.74%. The results indicated similar phenomena were found both in rectangular and canal banks. The case with a shallower (lower hw/T) and a narrower (lower Bc/Bs) canal dimension has a higher resistance value. Backflow and subsidence of free surface became significant around the ship's hull in more restricted water, changing the ship's hydrodynamic characteristics and increasing resistance. It can be found that the higher the blockage ratio (mb), the higher the total resistance value in both canal types, which proved that ships with higher speeds were more sensitive to changes in waterway restrictions.

Hydro-dynamic and geochemical assessment of three successive cutoff meanders of the Danube Delta

Abstract Hydrological and sedimentological data were collected on several cross-sections of both natural and artificial canals of three cutoff meanders (Mahmudia, Dunavăţul de Sus, and Dunavăţul de Jos meanders) of the Sfântu Gheorghe branch at the beginning of June 2017. The hydrological data shows a heterogeneous distribution of water discharges: on the meanders of Mahmudia and Dunavăţul de Jos, most of the liquid flow passes through artificial channels. In the case of the Dunavăţul de Sus meander, the cut meander is the main transport channel for the liquid flow. The statistical analysis of chemical data evidenced an excellent quality of the bottom sediments, with few parameters exceeding the limits (for Ni, Cu, and Cr). These results correlated with the hydrological measurements made on each investigated cross-section.

Quantitative Analysis of Cone-Beam Computed Tomography Artifacts Induced by Nonmetallic Root Canal Filling Materials Using Different Fields of View: In Vitro Study.

Cone-beam computed tomography (CBCT) imaging artifacts can hinder accurate diagnosis of several conditions. The aim of this study was to quantify CBCT artifacts created by nonmetallic root canal filling materials using two fields of view (FOV). Root canals of twenty extracted maxillary central incisors (n = 20) were instrumented and randomly divided into four equal groups: canals in Group 1 were filled with gutta-percha, canals in Group 2 with mineral trioxide aggregate (MTA) and gutta-percha, canals in Group 3 with gutta-percha and glass-fiber posts, and canals in Group 4 with MTA and glass-fiber posts. Each tooth was mounted on a silicon block and scanned three times using a CBCT machine, first with a prefilling scan (control) and then with postfilling scans, using two different FOV (40∗50 mm and 80∗50 mm). Imaging software was used to measure grayscale pixel values of canal cross sections. Data were analyzed using t-test and paired t-test statistical tests, with statistical significance set at p ≤ 0.05. Dentin at the apical and middle third of the teeth showed a significant decrease in minimum grayscale values in association with gutta-percha (p = 0.027, p = 0.034). However, a wide 80∗50 FOV showed a significant increase in maximum grayscale values of coronal (p = 0.048) and apical dentin (p = 0.049). Glass-fiber posts in middle third cross sections also corresponded to an increase in maximum grayscale values (p = 0.018). Gutta-percha produced dark band artifacts in the root's middle and apical thirds, whereas white streak artifacts were produced by gutta-percha in the coronal third and glass-fiber posts in the coronal and middle thirds when imaged with a wider FOV. A smaller FOV is therefore recommended for CBCT imaging, as it produces fewer artifacts.

The EFFECT OF HYDROPHYTES ON THE PERFORMANCE OF SECONDARY CANAL

The hydrophytes in canal effect directly canal performance by reducing water velocity, enhances sedimentation and reduce canal cross section area which raise water level and reduces water flow. Indirectly the hydrophytes detaches from their origin and flow with water stuck with outlet and reduces its proportionality. In this regard a study was conducted on secondary canal known as Yar Husain Minor (YHM) of Maira Branch Canal, which is part of the Upper Swat Canal Irrigation System in Khyber Pakhtunkhwa, Pakistan. Maira Branch Canal and its secondary canal were designed for Crop Based Irrigation Operation (CBIO), which could supply irrigation water for maximum copping intensity (180%) even during peak periods of irrigation requirements. The current water allowance was 0.67 Ls-1 ha-1 (6.6 mm day-1), which was based on the maximum crop water requirements. The several challenges for operation of YHM and other secondary canals of Maira Branch came from physical barrier mostly in the form of hydrophytes on the performance of YHM canal. Further challenges came from the fact that it receives water from River Swat which is turbid in summer and River Indus (Tarbela Reservoir) which is clear with low turbidity. This caused sedimentation and growth of hydrophytes in the YHM. Furthermore Triangular Profile Crump’s weirs were in all secondary canals including YHM for proportional division to the tertiary outlets (moghas). The study objectives were to investigate the effects of hydrophytes on canal capacity and at the outlets on the performance of the YHM. Hydrophytes growth was observed in head reaches of canal and samples were collected and were identified at the Department of Weed Science &amp; Botany, The University of Agriculture Peshawar. Five types of aquatic weeds were identified. The hydrophytes growth in canal head reaches directly reduces the cross section by more than 50%. Indirectly the detached hydrophytes were get stuck in the outlets and affected its performance. Therefore, daily discharges were measured with/without detached hydrophytes at each outlet from staff gauging. Frequency was based on days stone hydrophytes present divided by total time. It was concluded that secondary canal performance was low due to hydrophytes. The hydrophytes and users interventions influenced the outlets performance by 80%. Trifurcators type outlets were more prone to influence by hydrophytes followed by bifurcators outlet.&#x0D;

Three-dimensional morphologic classifications and analysis of canal isthmuses in permanent molars.

To investigate the three-dimensional morphology of isthmuses in molars according to their boundary characteristics using micro-computed tomography (micro-CT). Micro-CT reconstructed images of 248 molars were evaluated. Isthmuses were classified into four types based on the boundary characteristics: isthmus with roof, isthmus with floor, band-shaped isthmus, and isthmus without boundary. The tooth and root with isthmuses, the number and location of the isthmuses in the root, and the canal configurations were recorded. The maximum of the major diameter of all canal cross-sections in one isthmus (dmax), the minor diameter of the canal in same cross-section (dmin), the distance between the dmax cross-section and apex (Dm-a), isthmus length (Li), and distance from the isthmus ending cross-section to apex (De-a) were measured and analysed with a significance threshold set to 5%. Isthmuses were present in 75.4% specimens. The four types of isthmuses were found in various molars and roots. Their distribution in different root locations and canal configurations was significantly different. The dmax, dmin, Li, and De-a were analysed according to different molars and different isthmus types; their respective median values were 2.508mm, 0.07mm, 3.09mm, and 3.96mm. The three-dimensional classification of isthmuses according to the boundary characteristics provides a comprehensive picture of the isthmus in molars. Their corresponding distributions in different molars, location in roots, and canal configurations will be helpful in predicting the type of isthmus based on the tooth position and canal configurations.

Clinical and radiological results of indirect decompression after anterior lumbar interbody fusion in central spinal canal stenosis.

Whereas the benefits of indirect decompression after lateral lumbar interbody fusion are well known, the effects of anterior lumbar interbody fusion (ALIF) have not yet been verified. The purpose of this study was to evaluate the clinical and radiological effects of indirect decompression after ALIF for central spinal canal stenosis. In this report, along with the many advantages of the anterior approach, the authors share cases with good outcomes that they have encountered. The authors performed a retrospective analysis of 64 consecutive patients who underwent ALIF for central spinal canal stenosis with instability and mixed foraminal stenosis between January 2015 and December 2018 at their hospital. Clinical assessments were performed using the visual analog scale score, the Oswestry Disability Index, and the modified Macnab criteria. The radiographic parameters were determined from pre- and postoperative cross-sectional MRI scans of the spinal canal and were compared to evaluate neural decompression after ALIF. The average follow-up period was 23.3 ± 1.3 months. All clinical parameters, including the visual analog scale score, Oswestry Disability Index, and modified Macnab criteria, improved significantly. The mean operative duration was 254.8 ± 60.8 minutes, and the intraoperative bleeding volume was 179.8 ± 119.3 ml. In the radiological evaluation, radiological parameters of the cross-sections of the spinal canal showed substantial development. The spinal canal size improved by an average of 43.3% (p < 0.001) after surgery. No major complications occurred; however, aspiration guided by ultrasonography was performed in 2 patients because of a pseudocyst and fluid collection. ALIF can serve as a suitable alternative to extensive posterior approaches. The authors suggest that ALIF can be used for decompression in central spinal canal stenosis as well as restoration of the foraminal dimensions, thus allowing decompression of the nerve roots.

Improving the carrying capacity of irrigation canals: Al-Tawfiky diversion

ABSTRACT The morphological changes in the irrigation channel cross-section affect its hydraulic efficiency and carrying capacity with time. Periodic maintenance activities are applied to reach maximum carrying capacity. In many cases, removing the total amount of deposit inside canal cross-section above the design bed level is not the optimum maintenance solution hydraulically and economically. Additional discharge must be applied to canal intake to achieve the design water level. Al-Tawfiky Diversion is one of the main irrigation canals in the Delta region. It extended with a length of 175 km to serve 716,540 feddan. The study encloses the first reach from intake to km 36.400 upstream Jamjara regulator. This research aims to detect the most inefficient reaches along the selected study canal reach based on the actual characteristics of the surveyed canal cross-sections, and identifying the most proper maintenance scenario hydraulically and economically. Three hundred and fifty-one cross-sections along the study reach were surveyed. The different hydraulic parameters of these cross-sections were calculated. The data was analyzed and criterion for detecting the most inefficient sub-reaches was introduced. An empirical equation connecting the applied maintenance activities with channel conveyance was deduced. A mathematical model for the study reach was built and calibrated using (SOBEK-1D) to evaluate the proposed four maintenance scenarios.

IMPERVIOUS DEVICES OF OXIDATION POND IN A BASIN

The need to use anti-filtration devices in the biopond bowl usually arises when the levels of waste liquid in them exceed the surface water table in the banks of the gully and, therefore, it is possible for this liquid to spread out of the biopond. The fight against water filtration from the canals is carried out by forming a waterproof layer along the perimeter of the canal cross-section. This layer is made by covering the bottom and slopes of the channel with a lining of foreign material. The linings, depending on the design, serve not only to combat filtration, but also to protect the channel from erosion by water flow, wave and ice effects, etc. Anti-seepage coatings are made of clay and soil screens, screens made of polymer materials, concrete and reinforced concrete, asphalt concrete and bituminous linings. A biopond for biological wastewater treatment is a simple, useful and economical construction. Considering the sharply continental climate of the Aral Sea region (in winter up to -30 ° C, and in summer up to +40 ° C), anaerobic - aerobic biopondsare offered. In order to prevent contamination of groundwater in bioponds, it is necessary to provide anti-seepage screens. Anti-seepage coatings are made of clay and soil screens, screens made of polymer materials, concrete and reinforced concrete, asphalt concrete and bituminous linings

Adequacy assessment of an urban drainage system considering future land use and climate change scenario

Abstract Dhaka, the capital of Bangladesh, has been experiencing severe water-logging and urban flooding in the last few decades. In this paper, we estimate the peak storm runoff of Hatirjheel-Begunbari canal – the largest drainage system of the city – under different operational, land use and climate scenarios (2013, 2025 and 2040). Our method includes digital elevation model (DEM) reconditioning, watershed delineation, and development of future land use scenario. We apply HEC-RAS to check the adequacy of Begunbari canal cross-sections to carry peak runoff for the scenarios considered here. The Hatirjheel-Begunbari system is found to drain stormwater from ∼25% of the city. Within the system, built-up areas are increasing linearly by 0.8 Km2/year, whereas water body and wetlands are decreasing exponentially, which might increase the runoff coefficient by 11% in 2040 relative to 2013. Climate-induced change in rainfall intensity along with land-use change show three times higher runoff in 2040 than in 2013. Around 58% of canal cross-sections appear to be overflown at both banks while carrying a 5-year return period peak runoff under the 2013 scenario. For future scenarios, all sections seem to cause an overflow, which is alarming.

Anthropogenic Activity Effects on Canals Morphology, Case Study: Nile Delta, Egypt

Waterways are usually contaminated with wastes from industrial, domestic or irrigation sectors. Organizations in charge have adopted solutions to eliminate this problem; however, the adopted solutions contribute indirectly to modifying canal morphology during maintenance. These are examples of anthropogenic activity, as well as randomly implemented dredging, which expand the canal cross-sections. Egypt is a country which depends on surface irrigation through a huge network of canals. The majority of canals in Egypt are subject to anthropogenic activity which affects their efficiency. This study aims to assess the impact of conjugated instances of anthropogenic activity and dredging on canal morphology and capacity. Five canals were selected in the current study in the Nile Delta, Egypt. These canals are highly affected by two associated factors: anthropogenic activity by users and dredging by the government. The study also aims to determine the effects of a newly adopted policy for saving surface water through restoration of the canals’ originally designed cross-sections. The results showed a clear change in canal morphology, which has increased the volume of water in the affected canals. In some cases, the volume of water has increased by 59%, which could have negative consequences for Egypt’s water resources. Sustainable management of water resources in Egypt requires saving each water droplet, and canal rehabilitation is expected to save about 6.56 million m3/year by the year 2022.

Modelling the hydrodynamic effect of abrupt water depth changes on a ship travelling in restricted waters using CFD

ABSTRACT Shallow water studies of ship hydrodynamics typically examine a single, constant underwater canal cross-section at a time. In practice, the underwater cross-sectional area and shape of the waterway is rarely maintained constant over long distances. This study presents an attempt to quantify the effects of an abruptly varying water depth by numerically modelling such a condition using CFD. The results show that waves propagate and refract in the numerical towing tank in a physically consistent manner showing less than 0.1% error in the dissipation of a solitary wave when compared to analytical relations. A strong boundary layer is formed on the canal bottom almost as soon as the ship enters the shallower region. The resistance increase, resulting from the depth change is up to approximately 226% of the initial value near critical speeds.

Economics of reviving D.V.C. water supply canal amidst running supply to meet requirement of city of Durgapur, India

A water supply canal having a length of 8.9 km, originating from Durgapur Barrage at Durgapur, West Bengal, India and terminating in a pool at a downstream distance of 8.9 km was constructed by Damodar Valley Corporation during 1957-60 to supply drinking water to the city of Durgapur, West Bengal, India and water to several industries situated at Durgapur. Durgapur Municipal Corporation withdraws its complete demand from this canal of DVC. The major industries withdrawing water from the canal is M/S Durgapur Chemical Limited, M/S Durgapur Steel Plant, M/S Phillips Carbon, M/S Durgapur Thermal Power Station. Though the canal was designed for original capacity of 900 cusecs, but now there is withdrawal of about 400 cusecs only from the canal due collapse of the cross section of the earthen canal at different chainage, silting of the canal throughout its reach resulting in failure of the function of the canal to supply water to major customers. A study was undertaken to assess the present hydraulic and environmental conditions of the existing canal and propose procedure for revival of the canal in the most economic way without disrupting the present withdrawal from the canal and also suggest measures to be undertaken for maintenance of environment along the canal to prevent canal cross section from unlawful ingress of water into the canal. In this study, present hydraulic conditions of the canal have been analyzed. Different alternatives of reviving the canal to carry a discharge of 500 cusecs were attempted by (i) designing pre-cast section of the canal capable of carrying a discharge more than 500 cusec, (ii) simply using the existing cross section with side protection with steel sheet piling and bottom protection with concrete blocks, and (iii) providing diaphragm wall on each side of the section and bottom protection with concrete blocks. Feasibility of construction under conditions of continued supply to the existing stake holders was considered while analyzing the economics of revival for all the three alternatives. Revival of the canal by option (ii) has been recommended on the basis of economics of revival amid running condition of the canal. Though the working life of the canal with sheet pile protected side wall is less than that of the canal with diaphragm wall as the side wall of the cross section but workability under running condition of the canal is much higher for the case of side protection with steel sheet piles. Measures such as diverting the unlawful ingress away from the canal, protecting the side berms with green cover has been recommended to improve the environment around the canal.

Quantitative Analysis of the Anatomy of Mesial Roots of Mandibular First Molars with Vertucci Type I Root Canal Configuration by Means of Micro-Computed Tomography

Aim: This study aimed to evaluate root canal morphology of Vertucci type I root canal configuration detected in mesial roots of mandibular first molar teeth using micro-computed tomography (Micro-CT).&#x0D; Methodology: Micro-CT datasets of 269 specimens were evaluated for the detection of specimens with Vertucci type I root canal configuration for further analysis. Major and minor diameter, area, perimeter and roundness of root canal cross-sections at the beginning and midline of each root thirds were measured and recorded. The presence of apical delta, accessory canals, and deviation of major apical foramen from anatomical apex were investigated. Data was analyzed using descriptive analysis, ANOVA-Tukey and Kruskal-Wallis H-Wilcoxon signed-rank tests.&#x0D; Results: Vertucci type I canal configuration was present in the 4.46% of the specimens. The specimens often showed accessory root canals (50%) and apical deltas (41,6%). From the visual analysis of the 3D and 2D images, significant differences were detected among coronal, middle and apical thirds of the specimens regarding major and minor diameter, area, perimeter and roundness (P &lt; 0.05).&#x0D; Conclusion: Three- and two-dimensional analyses of mesial roots with Vertucci type I canal configuration indicated that this type of configuration presents large buccolingual diameters with long oval shape and has isthmus at coronal and middle thirds. At the apical third the root canals often terminate in an oval cross sectional shape.&#x0D; &#x0D; How to cite this article: Keles A, Keskin C. Quantitative analysis of the anatomy of mesial roots of mandibular first molars with Vertucci type I root canal configuration by means of micro-computed tomography. Int Dent Res 2020;10(1):17-21. https://doi.org/10.5577/intdentres.2020.vol10.no1.4&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Hydrodynamics of Canal Istanbul and its impact in the northern Sea of Marmara under extreme conditions

The Bosphorus, located at the junction of Asia and Europe, controls the transports of water, material, and energy between the Black Sea (BS) and the Mediterranean Sea. The Canal Istanbul (CI), planned by Republic of Turkey (TR), is a gigantic project which bisects the current European side of Istanbul, thus forming a secondary waterway parallel to the existing natural channel of the Bosphorus. The environmental impact of this project has been a major concern since the very beginning. To address this concern, a 3D hydrodynamic modeling study is carried out to investigate the impact of CI on the hydrodynamics and salinity of the northern Sea of Marmara (SM) by using the route and cross-section (CS) of canal, which was recently made public by the TR. An extensive set of model calibration is performed in a model where only the Bosphorus Strait links the Black Sea and Marmara Sea. Once the calibration process is completed, the future canal is added into the grid and new simulations are performed to analyze the influence of CI on hydrodynamics and salinities in the SM. It was found that the shallow water depth of CI is the limiting factor constraining the two-layer flow. Thus the vertical current structure of CI appears mostly as one-layer flow from the BS to the SM. One-layer flow from the SM toward the BS is rarely observed. In such cases, strong northerly storms caused water level setup at the SM and set down at the BS. Adding the CI in the model is responsible for a salinity decrease of ~1 ppt in the surface layer of SM. The salinity difference between the two models decreases gradually with the depth and it diminishes at the depth of 25 m.

Experimental Research of the Influence of Bedload Sediment Heterogeneity on Length, Height and Shifting Velocity of Growing Bed Configuration

In the natural current of water, the growing bed movement leads to a reduction of reservoir volume and canal cross-section area, filling by forebay of pump station and hydroelectric station pressure basins with sediment. This leads to abrasive wear of pumps, water turbines, and pressure pipelines, as well as other negative consequences. In many countries, rivers come laden with a large amount of sediment and enormous costs. At determining of sediment discharge it is important values of height and movement velocity of bed ridges. The determination of these values is based on experimental studies was not taken into account the heterogeneity of sediment with different fractions. For this reason, the calculated values according to obtained formulas have large discrepancies with field data. To eliminate these discrepancies, experimental studies were conducted using six types of fractions with the same weighted average diameter. Based on of laboratory data diagrams and interrelation were obtained for ridge length, height and movement velocity from sediment hydraulic and geometric sizes.