Underwater Rocks Research Articles

ДРЕЙФУЮЩИЕ НИТЧАТЫЕ ВОДОРОСЛИ В ПРИБРЕЖНОЙ ЗОНЕ ВОСТОЧНОГО КАСПИЯ КАК САМОСТОЯТЕЛЬНОЕ ВЕРХНЕПЕЛАГИЧЕСКОЕ СООБЩЕСТВО

The coastal zone of the Middle Caspian is currently undergoing significant changes due to falling sea levels. With shallowing, the nature of the influence of water flows on bottom landscapes changes, including the intensification of the impact of storm waves on their surfaces inhabited by bottom communities. The impact of rolling and storm waves on bottom algae is also increasing. Cenoses of bottom macrophyte algae, which was previously growing on underwater rocks, including flat rock platforms, which abound along the eastern coast of the Middle Caspian, at depths of 10-12 m, were previously affected only by particularly strong storm waves. Now their habitats are at a significantly shallower depth (about 7.5-9.5 m), which led to more frequent and massive detachments of macrophyte thalli and their transfer to the pelagic zone. Mass transfer of living thalli of green and red algae to the upper layers of the water column during different seasons of the year led to the formation of communities of a new type, differently structuring the surface layer of the phytopelagic zone. New cenoses are a set of metamorphosed thalli of filamentous algae with a microepiphytic complex abundantly growing on them, live in the surface layer of water for a long time, serve as food for pelagic fish and have a significant impact on coastal landscapes. Mass development of macrophytes on the bottom, and their further intensive development in the pelagic zone, in turn, can be caused by increased eutrophication of the coastal zone in areas of large settlements.

RDNN for Classification and Prediction of Rock or Mine in Underwater Acoustics

Mines in the waters are just explosives that detonate upon contact with an object. The underwater submarine must foresee if it will encounter a mine or a rock. Lacking the development of the Ranging Sound Navigation approach, which utilizes particular variables to identify whether a surface or a barrier is made of a mine or rock, finding mines or rocks would have been extremely difficult. In our study, we demonstrate a technique for predicting underwater rocks and mines using SONAR waves. At 60 different angles, SONAR pings are employed to record the various frequencies of submerged objects. To identify whether the object in the ocean is a mine or just a rock, the submarine uses SONAR signals, which transmit sound and receive switchbacks. The mine and rock categories are predicted using the prediction models. To create these prediction models, Supervised Machine Learning Classification methods were employed.

Experiments and simulation of block motion in underwater bench blasting

The blasting mechanism underlying drilling and blasting of underwater rocks, as an important component of the engineering blasting technology, has not been systematically studied. Laboratory model experiments are expensive and take a long time, while field tests fail to obtain timeous breakage and accumulation effects of underwater blasting, and may even be impossible. Considering this, a model experiment of underwater concrete bench blasting was designed, and the motion of blasted blocks was observed and evaluated with a high-speed camera. Then, numerical simulation was conducted based on Fluent and an engineering discrete element method coupling program complied using the application programming interface. Results show that the blocks form a bulge in the underwater blasting experiment under action of blast waves and expansion in the first period of bubble pulsation. Then, some blocks shrink in the first period of bubble pulsation. As the charge increases, the blast load exerts larger disturbance on the block group, resulting in significant motion of blasted blocks along the vertical direction. At the same time, the horizontal displacement of blasted blocks in the throwing direction increases.

Analysis of univariate linear, robust-linear, and non-linear machine learning algorithms for satellite-derived bathymetry in complex coastal terrain

The blue economic, maritime, and exploration activities rely on precise knowledge of coastal bathymetry. The recent trends in Satellite-Derived Bathymetry (SDB) research have focused on various methods of estimation using very high-resolution satellite imagery and in-situ data, but mostly in clear and transparent water. The Indian coastal region mostly has murky water, which is further constrained to employ SDB techniques in areas of river mouth and delta due to the presence of numerous underwater rocks and rich sediment carried by rivers. This study is focused on analyzing SDB in two study areas characterized as turbid, sediment-laden, and complex due presence of numerous underwater rocks. The objective of the research is to analyze and compare the performance of a few univariate Machine Learning (ML) regression algorithms in SDB estimation using ASTER, LANDSAT-8, and Sentinel-2A spectral bands with high resolution in-situ bathymetric data. This study evaluates linear, three robust linear Huber, RANSAC & ThielSen, and a non-linear Gaussian Process Regression ML algorithm, to analyze the efficacy in SDB estimation using a univariate spectral bandwidth of satellite imagery. The applied non-linear regression model has estimated SDB with the accuracy of R2 0.87, RMSE 1.77 m, and MAE 1.27 m for depth of 30 m in site A; and site B, R2 0.91, RMSE 1.51 m & MAE 1.17 m for depth of 22 m. The advantage offered by this approach includes; minimum required parameters, less processing time, and the potential to be an alternative to hydrographic surveys.

First record of mayfly Povilla (Languidipes) taprobanes Hubbard from Karnataka

Mayflies are important as macroinvertebrates of aquatic ecosystems and are reliable bioindicators of water quality. Most mayfly nymphs feed by scraping algae from underwater rocks or by extracting food particles in the littoral and benthic zones of the water bodies. The mayfly Povilla (Languidipes) taprobanes originally described from Sri Lanka was observed in plastic lined ponds in coastal Karnataka. Not only, this is the first report of the species from Karnataka, but the unique case making behaviour of this species is also described for the first time. Additionally, the species was found damaging plastic tarpaulins of 750 gsm thickness used as lining for water storage in the tank by chewing. This chewing behaviour was responsible for damage of plastic sheets leading to water leakage. The possible loss caused and a need of alternate strategies to store water is discussed.

PELVIC FLOOR MUSCLE TRAINING USING BIOFEEDBACK THERAPY VERSUS BILATERAL POSTERIOR TIBIAL NERVE STIMULATION FOR TREATMENT OF OBSTRUCTED DEFECATION A RANDOMISED CONTROLLED TRIAL

Obstructed defecation syndrome (ODS) is a type of constipation characterized by two or more of the following symptoms in more than 25 percent of defecation trials: straining, lumpy or hard stools, urgency, sense of incomplete evacuation, pelvic heaviness and manual maneuvers to promote defecation.obstructed defecation is of two basic types: functional and mechanical. The functional type involves idiopathic megarectum, anismus (pelvic floor dys-synergy), and descending perineal syndrome, while the mechanical type includes rectocele, enterocele, internal rectal intussusception and overt rectal prolapse.An excessive straining is likely to be the “primummovens”, causing tissue weakness and organ descent, and often is due to longterm anxiety, muscle tension and resulting in non-relaxing puborectalis muscle. The increased straining causes pudendal nerve stretch which may lead to a pudendal neuropathy which affects the rectal sensations.ODS has been also defined as an “iceberg syndrome”, as the two most frequent lesions, i.e., rectocele and rectal internal mucosal prolapse, present in more than 90% of patients with ODS, are easily detectable and may be considered “emerging rocks”, whereas the “surgical ship” is likely to “sink” due to the “underwater rocks”, i.e., the occult lesions.

Mitigation Dredging in Seabed Geotechnical Engineering Study Using Marine 2D ERI and Textural Characteristics in Thengapattanam Harbour, South India

An able-bodied, due to the exposure of the rocks in the northeast part of the boat path, the construction of Thengapattanam port encountered a major problem of dredging. In Thengapattanam, 2D electrical resistivity imaging (ERI) method and geotechnical soil texture investigation was carried out during underwater rock exposure to alleviate the need for continued dredging operations. The 2D ERI Marine Resistivity of special carbon floating electrodes with Wenner configuration technique used in this study. Res2DINV software was used to interpret the collected resistivity data to develop the apparent resistivity and pseudo-profile of exposed rock and soil in underwater. The Magneto Telluric Resistivity technique is used to locate the underground rock features of the port rock formation in deep mapping. The 2D picture shows the resistivity range of the three layers, such as top soil (0.06–0.9 Ω m soil contains clay), 1–1.5 Ω m sandy loam and 1.5–6 Ω m weathered gneiss, indicating subsurface geological conditions in the area. The support for texture analysis includes sampling, screening, weighing and calculation of graphic study for consolidation package of soil and rock formation. Marine 2D ERI and Magneto telluric resistivity studies are used for determine the formation of underwater rocks in river and coastal environments.

Measurement of Nearshore Seabed Bathymetry Using Airborne/Mobile LiDAR and Multibeam Sonar at Hujeong Beach, Korea

Do, J.D.; Jin, J.-Y.; Kim, C.H.; Kim, W-.H.; Lee, B-.G.; Wie, G.J., and Chang, Y.S., 2020. Measurement of nearshore seabed bathymetry using airborne/mobile LiDAR and multibeam sonar at Hujeong Beach, Korea. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1067-1071. Coconut Creek (Florida), ISSN 0749-0208.Accurate bathymetric measurements are important, especially in nearshore areas, because coastal sediment transport and the resulting beach erosion/accretion processes are significantly affected by seabed topography. At Hujeong Beach in Korea, for example, local shorelines show severe spatiotemporal variations as a result of seabed topography including underwater rocks. The accuracy of bathymetry measurements are not guaranteed, however, because high-accuracy acoustic sensors—such as multi-beam echo sounders—have a limited measurement capability. In this study, we investigated the accuracy of the nearshore bathymetry at Hujeong Beach using airborne LiDAR (a-LiDAR) data from May, 2017. One of the benefits of a-LiDAR is its ability to conduct both onshore and offshore mapping by detecting laser pulses reflected from land, the sea surface, and seabeds. The a-LiDAR measurements were validated onshore in a sloped roadside area using data measured via ship-mounted mobile LiDAR (m-LiDAR). A high agreement was found between the two datasets, with R-squared values of 0.9999 and mean square errors less than 0.05 m2. In measurements of seabed bathymetry, a-LiDAR agreed well with measurements from a multi-beam echo sounder over a sandy seabed and showed an accuracy similar to the m-LiDAR validation results. However, the accuracy of a-LiDAR measurements decreased significantly over rocky seabed; the mean square error compared to the multi-beam data increased to 0.6–0.8 m2. The high a-LiDAR errors over this rocky area may be a consequence of the irregular shape of its surface. Return signals from underwater rocks of varying shapes may be spread over wider angles, causing signal interference and reducing the measurement resolution in the area.

Video Monitoring of Shoreline Positions in Hujeong Beach, Korea

Shoreline processes observed by a video monitoring system were investigated under different wave conditions. A 30 m-high tower equipped with video cameras was constructed in Hujeong Beach, South Korea, where coastal erosion was suspected to occur. Two-year shoreline data since December 2016 showed that beach area, Ab, has decreased, but periods of rapid increase in Ab were also observed. Shoreline change was closely related to the wave propagation directions and bottom topography. Ab increased when waves approached the shore obliquely, whereas it decreased when they approached in a normal direction. The shoreline became undulated when Ab increased, while it became flatter when Ab decreased. The undulation process was influenced by nearshore bedforms because the shoreline protruded in the lee area where underwater rocks or nearshore sandbars actively developed, with a sheltering effect on waves. Specifically, the locations of shoreline accretion corresponded to the locations where the sandbar horns (location where a crescentic sandbar protrudes toward the shore) developed, confirming the out-of-phase coupling between sandbars and shoreline. When waves with higher energy approached normal to the shore, the sheltering effect of sandbars and underwater rocks became weaker and offshore sediment transport occurred uniformly along the coast, resulting in flatter shorelines.

Underwater rocks of anti - helicobacter therapy

The publication was prepared to systematize the data of the literature and our own research on the practice of effective eradication therapy of patients with HP-associated diseases. The most significant factors influencing the effective implementation of modern anti-Helicobacter therapy regimens should be adherence of physicians to the use of clinical guidelines, patient adherence to prescriptions and recommendations of specialists, as well as adherence to eradication treatment protocols.

Management of obstructed defecation.

The management of obstructed defecation syndrome (ODS) is mainly conservative and mainly consists of fiber diet, bulking laxatives, rectal irrigation or hydrocolontherapy, biofeedback, transanal electrostimulation, yoga and psychotherapy. According to our experience, nearly 20% of the patients need surgical treatment. If we consider ODS an "iceberg syndrome", with "emerging rocks", rectocele and rectal internal mucosal prolapse, that may benefit from surgery, at least two out of ten patients also has "underwater rocks" or occult disorders, such as anismus, rectal hyposensation and anxiety/depression, which mostly require conservative treatment. Rectal prolapse excision or obliterative suture, rectocele and/or enterocele repair, retrograde Malone's enema and partial myotomy of the puborectalis muscle are effective in selected cases. Laparoscopic ventral sacral colporectopexy may be an effective surgical option. Stapled transanal rectal resection may lead to severe complications. The Transtar procedure seems to be safer, when dealing with recto-rectal intussusception. A multidisciplinary approach to ODS provides the best results.

Party under the sea

A 52-year-old man presented for a computer tomographic examination of the abdomen for evaluation of liver nodules detected on previous ultrasonogram. As we read the images, we were amused to see a few sea animals having a party under the sea. A humpback whale is swimming slowly along the surface of the clear blue water. A jellyfish is floating gracefully in the water. An octopus is crawling on the ocean floor and is trying to squeeze through the narrow slit between the underwater rocks. A lobster is enjoying the warm and calm waters. A beautiful sea shell is lying on the sea shore.

Analysis of the marine traffic safety in the Gulf of Finland

The Gulf of Finland (GOF) is geographically situated between Finland and Estonian waters. The seafloor varies between deep and shallow and a number of underwater rocks exist in the Finnish archipelago area. The marine traffic has been growing fast during the last years in this area, especially due to the rapid increase of the transportation of various cargoes to Russia and the transport of oil from Russia. In this paper the safety of the marine traffic in the GOF area is analysed. First a detail accident statistics during the last 10 years are described and thereafter the risk of ship collisions is studied by theoretical modelling in two locations. Finally the results of the theoretical models are compared with actual accident statistics. The results reveal that grounding is the dominating accident type in these waters and typically about 11 groundings take place annually, of which about one is a tanker grounding. For collision the highest risks are caused by the passenger ship/RoPax ships traffic between Helsinki and Tallinn together with the high traffic intensity eastwards/westward to and from Russian harbours. The theoretical collision models give good results when compared with the accident statistics. AIS data is utilised in the theoretical models to calculate the geometric collision probabilities.

A prospective evaluation of occult disorders in obstructed defecation using the ‘iceberg diagram’

Surgical treatment of constipation and obstructed defecation (OD) carries frequent recurrences, as OD is an 'iceberg syndrome' characterized by 'underwater rocks' or occult diseases which may affect the outcome of surgery. The aim of this study was to evaluate occult disorders in order to alert the clinician of these and minimize failures. One hundred consecutive constipated patients with OD symptoms, 81 female patients, median age 52 years, underwent perineal examination, proctoscopy, anorectal manometry, and anal/vaginal ultrasound. Anorectal physiology and imaging tests were also carried out when indicated, as well as psychological and urogynaecological consultation. Symptoms were graded using a modified 1-20 constipation score. Both evident (e.g. rectocele) and occult (e.g. anismus) diseases were prospectively evaluated using a novel 'iceberg diagram'. The type of treatment, whether conservative or surgical, was also recorded. Fifty-four (54%) patients had both mucosal prolapse and rectocele. All patients had at least two occult OD-related diseases, 66 patients had at least three: anxiety-depression, anismus and rectal hyposensation were the most frequent (66%, 44% and 33% respectively). The median constipation score was 11 (range 2-20), the median number of 'occult disorders' was 5 (range 2-8). Conservative treatment was carried out in most patients. Surgery was carried out in 14 (14%) patients. The novel 'iceberg diagram' allowed the adequate evaluation of OD-related occult diseases and better selection of patients for treatment. Most were managed conservatively, and only a minority were treated by surgery.

A prospective evaluation of occult disorders in obstructed defecation using the ‘iceberg diagram’

Surgical treatment of constipation and obstructed defecation (OD) carries frequent recurrences, as OD is an 'iceberg syndrome' characterized by 'underwater rocks' or occult diseases which may affect the outcome of surgery. The aim of this study was to evaluate occult disorders, in order to alert the clinician of these and minimize failures. One hundred consecutive constipated patients with OD symptoms, 81 women, median age 52 years, underwent perineal examination, proctoscopy, anorectal manometry and anal/vaginal ultrasound (US). Anorectal physiology and imaging tests were also carried out when indicated, as well as psychological and urogynaecological consultations. Symptoms were graded using a modified 1-20 constipation score. Both evident (e.g. rectocele) and occult (e.g. anismus) diseases were prospectively evaluated using a novel 'iceberg diagram'. The type of treatment, whether conservative or surgical, was also recorded. Fifty-four (54%) patients had both mucosal prolapse and rectocele. All patients had at least two occult OD-related diseases, 66 patients had at least three of them: anxiety-depression, anismus and rectal hyposensation were the most frequent (66%, 44% and 33%, respectively). The median constipation score was 11 (range 2-20), the median number of 'occult disorders' was 5 (range 2-8). Conservative treatment was carried out in most cases. Surgery was carried out in 14 (14%) patients. The novel 'iceberg diagram' allowed the adequate evaluation of OD-related occult diseases and better selection of patients for treatment. Most were managed conservatively, and only a minority were treated by surgery.

Exposure dating of underwater rocks: potential application to studies of land bridges during the Ice Ages

10Be concentrations for four underwater rock samples from the Tsugaru Strait, Japan were obtained. Most of the 10Be concentrations of these samples are higher than the expected steady state concentration at the relevant underground depth, implying that most samples have been pre-exposed during the last ice age. The model calculation of 10Be production using recent rates for underground production and parameters of sea level change, uplift rate and erosion rate of this study could be an essential tool for exposure dating applications for both underwater and marine terrace samples.

Exposure dating of underwater rocks: potential application to studies of land bridges during the Ice Ages

10 Be concentrations for four underwater rock samples from the Tsugaru Strait, Japan were obtained. Most of the 10 Be concentrations of these samples are higher than the expected steady state concentration at the relevant underground depth, implying that most samples have been pre-exposed during the last ice age. The model calculation of 10 Be production using recent rates for underground production and parameters of sea level change, uplift rate and erosion rate of this study could be an essential tool for exposure dating applications for both underwater and marine terrace samples.

A comparison of two cartographic exposure methods using Fucus vesiculosus as an indicator

Morphological variation and vertical distribution of Fucus vesiculosus were quantified at several sites in the Finnish archipelago (Baltic Sea). F. vesiculosus samples were obtained from skerries at geographical distances of 1 km or more (large scale) and at intervals of ca 100 m around a single island (small scale). The results were examined in relation to wave exposure, calculated by Baardseth and effective fetch cartographic methods. Despite the fact that the exposure indices were calculated differently they correlated strongly. Vegetative morphological characteristics of F. vesiculosus illustrate the morphological differences both within and between exposure gradients. The tallest and widest F. vesiculosus plants were found at the sheltered end of the large-scale exposure gradient. Those from equally sheltered sites of the island were smaller in all respects. Thus, the trend from small narrow plants to large wide sheltered plants was expressed differently over the different geographical scales. Consequently localities with similar exposure indices may have morphologically different F. vesiculosus populations. Shores with similar cartographic exposure indices can be different in nature. Underwater topography and shore locations, either close to the mainland or at the outermost sites of the archipelago, affect the exposure. Although a sheltered shore is indicated, the sublittoral zone may be quite exposed to the movements of water. In contrast, in an open shore environment underwater rocks, boulders and shallow water areas can provide sheltered habitats. The depth range of the F. vesiculosus belt exhibited two distinctive patterns. At sheltered sites, around islands in the outermost reaches of the archipelago F. vesiculosus can grow to a maximum depth of 5 m. In exposed habitats the belt becomes narrower, reaching a maximum depth of 3 m. Closer to the mainland F. vesiculosus is found at exposed sites to a maximum depth of 5 m; the depth range at sheltered sites is narrower, only reaching depths of 2 m or less. In conclusion, the changes in plant morphology and in the vertical belt distribution are similar to each other along both gradients at the exposed ends of the wave action spectrum; however, the two gradients diverge at the sheltered ends of the spectrum.

Experience in drilling and blasting operations to Loosen underwater rocks

1.With the large powder factor needed for good crushing of the rock the cost of drilling and blasting operations increased somewhat (by about 7–10%, i.e., by 0.7–1.0 ruble/m3). However, in this case the cost of removal of the loosened rock decreases markedly (by about 33%, from 6 to 4 rubles/m3), as a result of which the overall cost of underwater rock-removal works decreases. Therefore crushing of rock underwater is performed more economically with an increased powder factor. 2.The high indices obtained with respect to labor productivity and cost of drilling and blasting operations can be improved mainly by more productive drills (instead of type BMK), since drilling occupies about 60% in the total labor intensity of the operations. 3.The performance of drilling and blasting operations from the FDR has many advantages compared with the performance of operations from the usual floating means.