Bed Thickness Research Articles

Evaluation of nail psoriasis with ultrasound enhanced blood flow imaging (eflow) and Power Doppler (PD).

The aim of this study was to assess the discriminative utility of nail features detected by B-mode (BM), enhanced flow (eflow) and power Doppler (PD) in patients with psoriasis or nail psoriasis (NP) and healthy controls. Ultrasound appearance of nails was investigated in 5 patients with NP, 8 patients with psoriasis and 7 healthy controls. In total, 195 nails were examined. The thickness of the nail bed (TNB), the thickness of the nail plate (TNP) and the thickness of the nail matrix (TNM) did not differentiate between NP and psoriasis in longitudinal and cross-section of nails. Resistance index (RI) in nails was higher in patients with NP than in patients with psoriasis, and significantly higher in patients with psoriasis than in healthy controls. TNP between patients with psoriasis and healthy controls was statistically insignificant in longitudinal section of nails, but higher than that in the cross-section of nails. TNM was higher in patients with psoriasis than in healthy controls. The ultrasound features of NP in longitudinal and cross-section of nails, nail bed (NB) eflow and PD signal were statistically significant among patients with NP or psoriasis and healthy controls. In patients with NP, there was a correlation between the ultrasound features of NP in longitudinal and cross-section of nails and nail psoriasis severity index (NAPSI). Our study displayed the usefulness of ultrasound nail examinations in psoriatic nails, not only assessing ultrasonic features of nails and proving correlation between ultrasonic features of nails and NAPSI, but also comparing the accuracy of new technology of blood flow signal in nails.

Spatial distribution and reserve estimation of sand and gravel deposits using geostatistical methods in west Basrah, southern Iraq

Sand and gravel are among the most common natural materials. They are generally used as a raw material in concrete, road construction, mixing with asphalt and filling material, among other uses. Sand and gravel deposits are widespread within the southern and central regions of Iraq. Among these deposits are the alluvial sand and gravel that form the upper part of the Dibdibba Formation in the Al-Rafiya, Al-Tuba, Chwaibda and Safwan blocks in west Basrah, southern Iraq. In this research, grain size distribution for channel samples collected from each block was determined. Thickness of overburden and industrial beds was measured and the stripping ratio (SR) was calculated. Geostatistical interpolation approaches including inverse distance weighting (IDW) and ordinary kriging (OK) were utilised to predict the spatial distribution of sand and gravel deposits and their reserves from borehole data. Data validation using the mean error (ME) and root-mean-square error (RMSE) were applied. The deposits can be characterised as gravelly sand (gS) in the Al-Tuba, Al-Rafiya and Chwaibda blocks, while it is a sandy gravel (sG) in the Safwan block. The overburden gypcrete beds varied between 1 and 3 ​m thick, while the industrial sand and gravel beds which appear as planar and sometimes lenticular deposits ranging between 3 and 8 ​m thick. The SR is generally low, considering the easily removed lightweight material of the overburden bed and the easily extractable fairly flat and near-surface friable sand and gravel deposits. Reserves are estimated as 376.63 Million m3 and 385.97 Million m3 using the IDW and OK approaches, respectively. Based on the least error values of ME and RMSE, we conclude that the OK method is the more accurate spatial interpolation approach for sand and gravel reserve estimation in all blocks compared to the IDW method.

Cost-Effective Utilisation of Industrial Fly Ash Waste in Treatment of Domestic Wastewater

In the present research an economically effective porous fly ash-based filter candle (FFC) was developed for the treatment of domestic wastewater using fly ash, sodium silicate, wood dust, silica fume and water. The four testing specimens of FFC having different sizes (10, 20, 30, and 40 mm) were prepared. The parameters such as turbidity, total suspended solids (TSS), dissolved oxygen (DO), total dissolved solids (TDS), and pH of domestic wastewater were studied before and after treatment. The test results showed that there is a decrease in values of turbidity from 7 to 5.9 NTU, TSS from 300 to 218 mg/L, TDS from 400 to 302 mg/L, pH from 10.6 to 7.9, and BOD from 9.5 to 7.9 while DO values decreased in the range of 8.9 to 7.7. The observed porosity, compressive strength, and flow rate of FFC fall in the range of 24.55-27.26 %, 1.5-2.3 MPa, and 180-290 ml/h, respectively. The filtration tests using FFC exhibited good performance with >92 % filtration efficiency. Overall results have shown that FFC having a 30 mm bed thickness is recommendable for effective wastewater treatment. Thus, an attempt has been made to introduce a novel technology for domestic wastewater treatment using industrial fly ash waste.

REMOVAL OF FLUORIDE FROM DRINKING WATER THROUGH LOW-COST TECHNIQUES

Fluoride ions (F-) from natural sources or industrial wastewater are the main cause of many pathological conditions in people living in more than 25 countries. Thus, removing F- from drinking water is pivotal for preventing serious health consequences. The WHO recommends a limit of 1,5 mg/L for fluoride in drinking. Excessive amounts of fluoride in drinking water are prevalent in Pakistan, leading to related health risks. Low-cost techniques for the defluoridation of drinking water can be used. In this study, the removal of fluoride from drinking water by an adsorption method using low-cost materials/adsorbents, such as marble chips, wheat husks, rice husks, egg shells, concrete, fuller earth, fly ash, freshly fired bricks, and charcoal, at different contact times and different bed thicknesses were investigated. A batch sampling technique was used for sample collection. On average, marble chips, wheat husks, rice husks, egg shells, concrete, fuller earth, fly ash, freshly fired bricks, and activated charcoal (rice husk) resulted in 71,99 %; 90,99 %; 66,73 %; 90,99 %; 63,30 %; 71,99 %; 22,60 %; 49,67 %; and 90,13 % fluoride removal, respectively. Therefore, defluoridation using these materials is desirable. The performance of adsorbents depends on parameters such as contact time, depth of the adsorbent media, and pH. The bed thickness of the adsorbent has a minor effect on fluoride removal. The major contributors to fluoride removal from water are contact time and adsorbent composition.

Compositional variation of the Zechstein Group in the Norwegian North sea: Implications for underground storage in salt caverns

AbstractHalite beds in the upper Permian Zechstein Group represent an opportunity for the future development of underground storage caverns. However, geological factors such as lithological heterogeneities, cap rock characteristics and depth can affect the sealing capacity and the integrity of the cavern or contaminate the stored fluid. The main objective of this paper is to evaluate these factors focusing on the compositional variation of the Zechstein Group in different salt structures in the Norwegian North Sea, and related opportunities and challenges for salt cavern storage. Based on deformation style, geometry, height and thickness of the salt structures, we have divided the Zechstein Group into four main categories: (1) thin beds, which can be either carbonate‐anhydrite or clastic dominated. Halite is absent and therefore there is no potential for the development of salt caverns. (2 and 3) bedded to weakly deformed evaporites and intermediate size salt structures, where thick halite beds of more than 300 m are present, but they are usually deeper than 2000 m. Lithological heterogeneities in the halite consist of a mix of competent and incompetent (K‐Mg salts) lithologies. (4) Tall diapirs, characterized by shallower structures (<2000 m), with large deformation and poor seismic image. Thin layers of incompetent K‐Mg salts are observed in these diapirs. The composition, thickness and deformation of the cap rock vary greatly in the area. Thick halite beds are recognized in most salt structures, suggesting an opportunity for underground storage. The challenges are related to the depth of the halite, amount and type of heterogeneities, characteristics of the cap rock and deformation in the different salt structures. These results also have implications for the distribution of reservoir and source rocks, and the evolution of the Northern Permian Basin.

Emplacement history of volcaniclastic turbidites around the central Azores volcanic islands: Frequencies of slope landslides and eruptions

Volcanic islands export clastic material to their surrounding oceans by explosive eruptions, lava emissions, biogenic production on their shelves, and failure of their slopes, amongst other processes. This raises the question of whether geological events (in particular, eruptions and landslides) can be detected offshore and dated, and whether any relationships (for example, with climate changes) can be revealed using sediment cores. The volcanically active central Azorean islands (Faial, Pico, São Jorge, and Terceira), with their neighboring submarine basins, are potentially good candidates for such an analysis. Here, chronostratigraphies of four gravity cores collected amongst the islands are constructed based on twelve radiocarbon dates and two dates derived by geochemically correlating primary volcaniclastic turbidites with ignimbrites on Faial and Terceira Islands. Age-depth models are built from the hemipelagic intervals to estimate individual turbidite dates. Volumes of turbidites are modeled by multiplying basin areas with bed thickness, allowing for various turbidite thinning rates and directions. The volumes of landslide-generated turbidites are only comparable with the largest volumes of their adjacent upper-slope submarine landslide valleys; therefore, such turbidites in the cores likely derive from these largest landslides. Emplacement intervals between turbidites originating from both landslides and pyroclastic density currents are found to be mostly a few thousand years. Frequencies of landslide-generated turbidites and hemipelagic sedimentation rates were both highest in the past 8 k.y. compared to preceding periods up to 50 k.y. High hemipelagic sedimentation rates are interpreted to be related to sea-level rise, allowing more shelf bioproduction and release of particles by coastal erosion. The coincident increased frequencies of submarine landslides may also be associated with the increased sediment supply from the islands, resulting in a more rapid build-up of unstable sediments on submarine slopes. Notably, the emplacement frequencies of turbidites of pyroclastic density current origins do not suggest the decreased eruption frequency toward the Holocene that has been found elsewhere.

Corneal Biomechanics After SMILE, Femtosecond-Assisted LASIK, and Photorefractive Keratectomy: A Matched Comparison Study.

To evaluate the change in corneal stiffness after small incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and photorefractive keratectomy (PRK). Age, gender, spherical equivalent, and central corneal thickness (CCT)-matched cases undergoing SMILE with a 120-µ cap, FS-LASIK with a 110-µ flap, and PRK were enrolled. One-year change in the stress-strain index, stiffness parameter at first applanation, integrated inverse radius, deformation amplitude ratio at 2mm, and deformation amplitude ratio at 1mm were compared between the surgical groups by linear mixed-effect models. Within each surgical group, 120 eyes completed 1year of follow-up. The residual stromal bed (RSB) thickness and (RSB/CCTpostop) were 348.1 ± 35.0 (0.74), 375.4 ± 31.0 (0.77) and 426.7 ± 2 µm (0.88) after SMILE, FS-LASIK, and PRK, respectively. The 1-year change in all biomechanical indices was significant, except the stress-strain index with PRK (P = 0.884). The change in all indices with SMILE were significantly greater than with FS-LASIK and with PRK (all P < 0.01), except the deformation amplitude ratio at 1mm change between SMILE and FS-LASIK (P = 0.075). The changes in all indices with FS-LASIK were significantly greater than with PRK (all P < 0.05). Although SMILE preserves the greatest amount of anterior cornea with a cap thickness of 120 µ, this also produces the smallest RSB and the greatest decrease in stiffness. Thus, the RSB is shown to be the predominant determinant of stiffness decreases, rather than the preserved anterior cornea. We recommend using a thinner cap to achieve a thicker RSB and a lesser decrease in the corneal stiffness in the SMILE procedure. After refractive surgery, RSB is predominant determinant of stiffness decreases, rather than the preserved anterior cornea.

Investigation and mapping of geological construction materials in parts of chemoga river sub basin, debre markos, Ethiopia

Currently the demands of geomaterials are intensively increasing all over the country regarding to the expansions of towns for the consumption of engineering structures and buildings. Therefore, searching workable, serviceable and accessible geomaterials nearby areas is a vital subject to stabilize the inflation of geomaterials. The present research was carried out in the Chemoga river sub basin in the Southern direction of Debre Markos town, North Western Ethiopia. To meet out the objectives, detailed surface explorations were carried out through systematically selected travel lines (across the strike and along streams) to detect the different lithologic formations and the contacts; A number of representative rock samples were collected for visual interpretations; GPS reading and metallic meter were the materials used in the field to quantify stratigraphic units, bedding thickness and lamination the lithologic formations; The Brunton compass was used in the field to measure the orientation (dip direction, dip amount and strikes) of geological structures. Besides to this, related literatures were reviewed to have a general background on the subject matter.Basalt and Sandstone are the dominant lithogical units in the study area and have existed with about an average thickness of 500 m and 145 m respectively. Fresh to slightly weathered basalt and columnar basalt that used as a masonry stones are ease to access, workable and the most dominant lithologic units in the study area. Fine to coarse grain reddish to light color sandstone interbedded with siltstone and mudstone is well exposed. Based on the detail field exploration and judgments, Sandstone unit has been well exposed in a desirable potential and quality. And based on the detail field investigation and researcher judgment, the sandstone resource could answer the demands of construction materials for the surrounding areas of Debre Markos town for several thousand of years. Geometrically, mostly massive and steep rock faces are well developed which are difficult for quarrying process and required high explosive materials. Generally, a sandstone rock unit is surrounded by three major normal faults and inaccessible as compared to basalt unit. Regarding to environmental influences/effects, the area is sparsely farmed and it is not common that an extractive activity does not show any environmental and social impacts. Chert is exposed on geographically limited area and rarely observed following stream cuts. Chert and basalt units are slightly to highly weathered and showed alterations on the surface. Finally, the potential and the spatial distribution of geomaterials are investigated and revealed on the map using ArcGIS software and on the basis of the findings of the present research, recommendations are forwarded.

Influence of layer thickness and substrate bed on the void fraction of powder layers for laser powder bed fusion

The spreading powder layer plays a vital role in determining the quality of Laser powder bed fusion (LPBF) -manufactured samples. In this study, the effect of layer thickness is investigated numerically and experimentally. It was determined that the void fraction at a certain height is higher than that of the entire layer, especially for thicker layers, because of gravity. The former is consistent with the experimental result for powders of the same thickness. The void fraction of the sintered part was also measured to confirm their relationship. Furthermore, the dynamics of spreading particles on a particle bed were numerically studied to investigate whether support powders around the sintered part affect the powder-spreading process. The powder layer on a particle bed is denser than that on an adjacent solid bed, suggesting that support powders will affect the powder-spreading of the sintered part, especially its borders, and contribute to the surface topography.

Костяные изделия со стоянки среднего палеолита Рожок I (культурный горизонт VI) в Северо-Восточном Приазовье

The multilayer site of Rozhok I is a reference object for the study of the Middle Palaeolithic in the south of the Russian Plain. The well-preserved cultural remains lying in a thick bed of loess-soil sediments may shed light on a number of questions regarding the chronology and cultural affinities of the regional Middle Palaeolithic industries, as well as the economic activity of their makers and the character of manufacturing technologies used to produce stone and bone tools. Of special interest is a series of bone artifacts identified among faunal remains from cultural horizon VI. These include both lightly and heavily modified objects, some of which appear to have been associated with symbolic behavior. The paper presents the results of an in-depth technological analysis of these artifacts.

Assessment of CO2 storage prospect based on physical properties of Rio Bonito Formation rock units

The physical properties of the rock units associated with the Rio Bonito Formation are presented in this study with the focus on modelling reservoir quality based on petrophysics-derived parameters to evaluate CO2 storage potentials. It involves the modelling of the reservoir depths, thicknesses, flow zone indicators (FZI), and effective permeability (Keff) and presenting the CO2 storage efficiency factors peculiar to the rock units of the study location. Research results presented by this study for the stated objectives are not quite common in the region. Keff values range from 200 mD to higher than 2000 mD, and FZI values are generally above 1.0 μm and up to 13.0 μm within the portions covered by the drilled wells. The sandstone units recorded are up to 20 m thick in some cases. The Keff and FZI models indicate the sandstone reservoirs as permeable units to support the injection and circulation of CO2 within the potential reservoir units of the Rio Bonio Formation across São Paulo State. Apart from some points in the southeastern part of the study location, where the Rio Bonito are delineated at depths less than 800 m (minimum CO2 storage depth based on best practices), other portions are deeper, ranging from 950 m to 3500 m. Thin-bedded layers will affect the integrity of the rocks as CO2 storage tanks or reservoir seals/traps/overburden within the region. Sandstone bed thicknesses are up to 20 m in some cases. However, hybrid CO2 reservoir units are feasible, especially in portions where thin siltstone layers are sandwiched between sandstone units to provide considerable thicknesses based on CO2 storage standards. The current study shows that useable areas considering reservoir thickness, depth, and other physical qualities will significantly control the CO2 storage efficiency of the study location. Further studies featuring a detailed geophysical exploration of the site to confirm the availability and saturations of pre-existing fluid (hydrocarbon and water) are encouraged to boost CO2 storage in the region. The related research-based results, as mentioned above, may be combined with the results of this research to determine the area's potentials for CO2 storage or hydrocarbon production with CO2 storage options.

Modelling analysis of a solar-driven thermochemical energy storage unit combined with heat recovery

Solar-driven thermochemical energy storage (TCES) can address the mismatch between solar heat production and heating demand and contribute to decarbonisation in buildings. In many studies of typical salt hydrate TCES systems, massive heat carried by the discharged humid airflow during the charging phase is not well-utilised but directly dissipated to the ambient. Therefore, a solar photovoltaic/thermal-powered TCES system integrating a heat exchanger (PV/T-TCES-HEX system) is proposed in this study for recovering this part of heat. To study the effect of adding the PV/T collector and heat exchanger (HEX) on the performance of the TCES system, the thermal performance of the PV/T-TCES-HEX system is compared with other two TCES systems via COMSOL modelling. Results suggest that the PV/T-TCES-HEX system requires an additional external electricity input of 11.86 kWh on a typical summer day in Nottingham, which is only 40.53% of the TCES-only system. The overall thermal efficiency of the PV/T-TCES-HEX system is 56.00%, indicating an efficiency enhancement of 146.80%. A lower mass flow rate leads to higher thermal efficiency and storage energy. The system has the highest overall thermal efficiency when the reactor bed thickness is 0.04 m (57.55%) and when the reactor bed length is 0.5 m (58.73%).

New stratigraphic and paleoenvironmental constraints on the Paleogene paleogeography of Western Amazonia

The rise of the Andes and the associated propagation of the retroarc foreland basin during the Mesozoic Cenozoic in western South America shaped the paleogeography and paleoenvironmental settings of Western Amazonia. Much attention has been paid to the Neogene evolution of the Amazonian Basin, but few studies have investigated in detail the paleoenvironments of Western Amazonia during the Paleogene. We present a multi-proxy study that includes new biostratigraphic and paleontologic data, the interpretation of depositional environments and zircon U–Pb data from the Upper Cretaceous-Paleogene sedimentary sequence exposed in the Huallaga Basin (northern Peru). The biostratigraphic dating suggests that the lower part of the sequence is Maastrichtian in age. The maximum depositional age and maximum likelihood age according to the U–Pb zircon dating of Paleogene sedimentary rocks indicate Lutetian to Bartonian ages (from 43.5 ± 0.64 Ma to 37.6 ± 0.85 Ma). These results reveal a hiatus in the depositional record during Paleocene time. Two depositional systems can be distinguished: a lacustrine system composed of red mudrocks interbedded with thick sandstone layers and carbonate beds, and a siliciclastic tide-dominated system composed of fine-to medium-grained sandstones associated with tidal bundles, reactivation surfaces and heterolithic stratifications. However, the carbon and oxygen stable isotope values in carbonates tend to characterize a freshwater system, with a transition to brackish conditions toward the upper part of the section (Bartonian), thereby suggesting the presence of an estuary system. Finally, we suggest that the Bartonian shallow marine incursion recorded in the Huallaga Basin occurred from the north through the Caribbean Sea, and that it might have played a role in regional biodiversity patterns in the Paleogene.

Controls on grain-size variability in the Holocene fill of the Indus Submarine Canyon

ABSTRACT What processes control grain size and bed thickness in submarine canyon deposits? Erosive, shelf-cutting canyons contrast with accretionary basin-floor submarine fan accretionary channels because the former tightly constrain turbidity flows in deep channels. This study addresses such a deep-water depositional system in the Indus Submarine Canyon using a series of cores collected along the canyon. Grain-size analysis was conducted for turbidite and hemipelagic sediment deposited in the Holocene Indus Submarine Canyon mostly by diffuse, fine-grained turbidity currents and hemipelagic hypopycnal plumes. We investigate the links between sedimentary grain size, bedding thickness, facies, and canyon morphology. Well-sorted silt in layers mostly &amp;lt; 2 cm thick dominates the canyon. Core sites in the canyon located downstream of knickpoints have coarser, less well sorted sediments because of current acceleration in these areas and then the slowing of flows downslope. Sediments fine with increasing height above the canyon thalweg, implying deposition from a turbulent plume head. The great depth of the canyon, caused by the exceptionally wide shelf and steep slope, prevents channel overspill which controls sedimentation and channel form in submarine fans. Thalweg sediment fines down-canyon into the mid canyon, where sediment bypassing is inferred. The thickest turbidites are found in the sinuous lower canyon where the gradient shallows from ∼ 0.7° to 0.3°. However, canyon gradient has little impact on mean grain size, but does correlate with bed thickness. The active canyon channel, located in a channel belt gradually becomes less steep, more meandering, and narrower farther downstream. Sinuosity is an influence on turbidite bedding thickness but does not control grain size, in contrast to the situation in submarine-fan channel–levee complexes. Compared to the well-known, more proximal Monterey Canyon of California the grain sizes are much finer, although both systems show evidence of &amp;gt; 200 m plume heads.

On Hole Cleaning Evaluation Method in Highly Deviated / Horizontal Well Sections

To solve the problem of hole cleaning quantitative evaluation in highly deviated / horizontal well sections, experiments are made on the experimental system of highly deviated / horizontal well sections, the influence laws of annulus return speed, pipe speed, drill tool eccentricity, well deviation angle, drilling fluid density and viscosity, cuttings size and other parameters on cuttings bed thickness are studied, and the calculation models of steady-state dimensionless cuttings bed thickness in horizontal well and highly deviated well are established, the calculation error is controlled within ±5%, which provides an accurate method for hydraulic parameter optimization and design.

Numerical Simulation on Shale Fragmentation by a PDC Cutter Based on the Discrete Element Method

During the guided drilling process as part of shale gas exploration and development, shale is damaged by a polycrystalline diamond compact (PDC) bit cutter. It is essential to carry out research on rock breaking by a PDC cutter. In this paper, we study the mechanism of shale fragmentation by a PDC cutter based on the discrete element method. Additionally, we consider the effects of bedding angle, bedding thickness, cutting depth and cutting rate on the rock-breaking efficiency of a PDC cutter. The results show the following: (1) With the increase in bedding angle, the number and area of microcracks first increase and then decrease, and the proportion of tension cracks is relatively unchanged; there is no significant change in the morphology of the failure zone, and the average particle size of the cutting fragments first decreases and then increases. (2) With the increase in the bedding thickness, microcracks continue to extend in a horizontal direction, the total number of cracks shows a fluctuated change, and the proportion of tension cracks increases. The failure zone extends in a conical shape in the horizontal direction, and the average size of the cutting fragments gradually increases. (3) With the increase in cutting depth and cutting rate, the number and area of microcracks increase, and the proportion of shear cracks increases; the area of the failure zone increases and the size of the cutting fragment decreases.

A Comparative Study on Appraisal of Lithological Boundaries and Litho-Models Using Well Log Data at Bhogpara Oil Field in Assam of NE India

Accurate assessment of bed boundaries at a drill site is a crucial step for reservoir characterization. Generally, the interpreters in oil industries carry out such analysis through expensive softwares based on their experiences and geological knowledge in the study area. However, identifying bed boundaries using traditional interpretation is tedious. In this study, we adopted a synergistic approach of Walsh transform and a bed boundary demarcation technique to discriminate the lithological boundaries in Bhogpara oil field of Assam in NE India. This bed boundary detection technique was tested over self-potential (SP), gamma ray (GR) and laterolog deep resistivity (LLD) logs. Initially, we detected the possible lithological boundaries from GR log variations and hence proposed a lithological model as per the knowledge of traditional log interpretation techniques. Subsequently, Walsh low pass filter was applied to the self-potential (SP), GR and LLD logs to obtain their step function. Afterward, the step functions of logs were processed through the boundary detection algorithm to find out the possible thick and thin beds. Further, bed correlation was made among the Walsh-detected boundaries for the studied wells of the Bhogpara oil field. Finally, a bed boundary model was generated using the boundaries picked from the Walsh-based approach. Our analysis exhibit that the model generated from Walsh boundaries more explicitly envisaged the possible heterogeneity. Traditionally we discriminated the minimum bed thickness of the order of 5.15 m, whereas, from the Walsh-based approach we obtained thin bed of the order of 3.2 m. This proposed bed boundary assessment technique is also helpful in understanding the position of subsurface rock layers as well as possible thick and thin beds when we don’t have any pre-received core information.

Morphological changes in a macro-tidal estuary during extreme flooding events

River discharge is a controlling factor in estuarine morphological changes; estuarine topography can be significantly altered even by only one flooding event. However, the mechanism of morphological changes in mountain-stream macro-tidal estuaries during wet seasons is not fully understood. Taking the Yalu River Estuary (YRE), China, as an example, this study aims to explore the effects of extreme flooding events on estuarine morphology. An improved Finite Volume Coastal Ocean Model (FVCOM) was applied in the YRE to reproduce the distribution of bed sediment erosion and deposition during dry years, normal years, and wet years. Sensitivity tests were conducted to assess the responses of the estuarine system to river discharge. The influence of the Yalu River on the magnitude of estuarine bed change was examined. With an increase in river discharge, the bed thickness in the main estuarine channel first increased and then decreased after reaching a threshold of 0.4 × 104m3/s. Simultaneously, density stratification became stronger with the increase in runoff. Subsequently, vertical mixing of water was weakened after a certain threshold, which in turn, enhanced the density stratification and changed the location of the Estuarine Turbidity Maxima (ETM). In addition, river effects contributed to nearly half of the bed erosion under 0.6 × 104m3/s (flooding with 50-year return period). The ETM extended and moved approximately 8 km seaward during flooding events. The West River channel experienced strong siltation, which was more significant during flood events. The results of this study demonstrate that estuarine circulation plays a key role in morphology change. The magnitude of bed thickness erosion can reach 22% of the total initial thickness during one flooding event. This rapid change is a threat to the stability of port infrastructures, and actions should be taken to maintain the safety of coastal construction.

Online sequential, outlier robust, and parallel layer perceptron extreme learning machine models for sediment transport in sewer pipes.

Sediment transport is a noteworthy task in the design and operation of sewer pipes. Decreasing sewer pipe hydraulic capacity and transport of pollution are the main consequences of continuous sedimentation. Among different design approaches, the non-deposition with deposited bed (NDB) method can be used for the design of large sewer pipes; however, existing models are established on limited data ranges and mostly applied conventional regression methods. The current study improves the NDB sediment transport modeling by utilizing wide data ranges, and furthermore, applying robust machine learning techniques. In the present study, the conventional extreme learning machine (ELM) technique and its advanced versions, namely the online sequential-extreme learning machine (OS-ELM), outlier robust-extreme learning machine (OR-ELM), and parallel layer perceptron-extreme learning machine (PLP-ELM) are used for the modeling. In the studies conducted in the literature, sediment deposited bed thickness (ts) or deposited bed width (Wb) was used in the model structure as a deposited sediment variable, and therefore, different parameters in terms of ts and Wb can be incorporated into the model structure. However, an uncertainty arises in the selection of the appropriate parameter among Wb/Y, ts/Y, Wb/D, and ts/D (Y is flow depth and D circular pipe diameter). In order to define the most appropriate parameter to best describe the impact of deposited sediment at the channel bottom in the modeling procedure, four various scenarios using four different parameters that incorporate deposited sediment variables at their structures as Wb/Y, ts/Y, W/D, and ts/D are considered for model development. It is found that models that incorporate sediment bed thickness (ts) provide better results than those whichuse deposited bed width (Wb) in their structures. Among four different scenarios, models that utilized ts/D dimensionless parameter, give superior results in contrast to their alternatives. Based on the outcomes, the OR-ELM approach outperformed ELM, OS-ELM, and PLP-ELM techniques. The results obtained from applied methods are compared to their corresponding models in the literature, indicating the superiority of the OR-ELM model. It is figured out that the thickness of the deposited bed is an effective variable in modeling NDB sediment transport in sewer pipes.

Estimating the skin dose near to the applicator and acute toxicity in breast cancer patients: An intraoperative electron radiotherapy technique.

Intraoperative electron radiation therapy (IOERT) is one of the most recently popular therapeutic methods for breast cancer. This study aimed to measure the skin dose near the applicator during IOERT of breast cancer patients, as well as, the incidence of acute toxicity after surgery. Thirty-six female patients participated in the current study with the prescribed dose of 21 and 12 Gy for IOERT as full and boost, respectively. The skin dose was investigated based on different applicator sizes, tumor bed thicknesses, and monitor units (MUs). The energy was chosen 8 MeV, and EBT3 film was used for the dosimetric process. In addition, the acute toxicity included healing time for the surgical wound, scaling of the skin, itching, necrosis, redness as well as seroma formation for 1 week and 1 month were recorded. The results were compared to those of 22 patients who underwent the surgery without IOERT. The highest skin dose for the patients was obtained 2.09 Gy, which is lower than the threshold dose (6 Gy). Furthermore, the findings showed that the average skin dose was higher in bigger applicator sizes and MU and lower tumor bed thicknesses. The average of wound healing for the patient underwent IOERT and without the use of IOERT (as the control group) was 19.32 and 11.67 days, respectively. One month after surgery, the volume of aspirated seroma was higher in the patients who performed IOERT compared to the control group (250 ml vs. 200 ml). It is notable that there were not observed any redness, itching, scaling, and necrosis in both investigated groups. Owing to the results, the skin dose during IOERT was lower than the recommended level. The dose of IOERT as a full was higher than boost which can be related to the lower number of the patients in full method; however, there was a well-tolerated without severe acute complication, especially seroma formation and wound healing time in both full and boost methods.