Depth Of Placement Research Articles

Позитивний вплив глибокого внесення добрив на їх агрономічну ефективність та урожайність сої і соняшнику на чорноземі

The aim of the research was to study the effect of increasing the depth of mineral fertilizer placement on their agronomic efficiency for crops differed in root system architecture. Available NPK in soil, chlorophyll content in the leaves, and yield of sunflower and soybean were measured in the field small-plot experiments on Luvic Chernozem during three years. It was found a higher efficiency of N60P60K60 placement for sunflower in form of mix of ammonium nitrate, ammophos and potassium chloride on 20-22 cm, and for soybean in form of nitroammophoska by two bands on 10-12 cm and 20-22 cm comparing to the common method of fertilizer applying by one band on the depth 10-12 cm. The maximum yield increase was 15% for soybeans, 36% for sunflower. The content of chlorophyll in leaves might be an additional indicator to optimize the technology of fertilizer application because it has close positive correlation with crops yield. The obtained results prove the need for an individual approach in choosing the optimal fertilizer band placement for each crop separately. In general, increased depth of fertilizer band placement is recommend as a measure for adapting agricultural technology to unstable and insufficient moisture.

A Two-dimensional Numerical Model of Heat Exchange in the Soil Massif During the Operation of a Shallow Horizontal Soil Heat Exchanger

The current article uses a two-dimensional numerical model to represent the results of theoretical studies of the heat exchange in the soil massif during the operation of a shallow horizontal soil heat exchanger. The analysis of literature sources showed that one of the important conditions for the effective operation of a shallow-soil heat exchange is its rational design parameters, such as the total length of the pipeline, the diameter of the pipe, the distance between the axis of the adjacent pipes, the depth of the heat exchanger placement, etc. A two-dimensional heat exchange model in the soil mass was developed, which made it possible to investigate the operation of a shallow horizontal soil heat exchanger. It was found that the step between the axis of the adjacent pipes of the multi-loop heat exchanger, which is 0.95 m, is optimal when creating a shallow horizontal soil heat exchanger in the soil conditions of Kyiv.

Performance of Artificial Neural Network and Modified Gravitational Search Algorithm Models to Predict Vibration Response of Geocell Reinforced Based Weak Sand

The use of a fast evolving artificial intelligence technology (AIT) to forecast the vibration response of maritime soil based on geocells is explored in this research. The vibration response is represented by an indicator called peak particle velocity (PPV). For the purpose of predicting PPV, the artificial intelligence techniques Artificial Neural Network (ANN) and Modified Gravitational Search Algorithm (MGSA) are employed. To create the dataset for the model, a number of field vibration tests were first performed over the geocell-reinforced beds. PPV variation was investigated by varying the test variables—footing embedment, dynamic load, infill material modulus, width, and depth of geocell mattress placement—during the test performed. The various statistical indicators were determined in order to evaluate the prediction performance of a constructed model. Plate load results on geocell-reinforced foundation beds have been used to validate the proposed hybrid ANN-MGSA model. High accuracy and consistency were found when the findings of the ANN-EHO, JSA, MOA, and RNN method were compared, particularly at predicted and actual resolution levels. A parametric sensitivity has also been examined in order to better understand the behaviour of geocell-reinforced structures

Effect of Fines on Strength of Granular Soil Reinforced with Geosynthetics

Geosynthetics (GSN) are polymeric products used in Geotechnical Engineering for the purpose of improving the properties of the insitu soil. In this project, experimental work was carried out to determine the influence of presence of fines within granular soil on the CBR strength of soil reinforced with different GSN (Woven geotextile, Non-woven geotextile, Geogrid and Geonet). Two types of granular soil in disturbed state containing varying percentage of fines were selected from in and around the Chennai region. Soil type 1 contains high fines of about 40% (SHF) whereas soil type 2 contains less fines of about 7% (SLF). Unsoaked CBR (U-CBR) test was carried on unreinforced soil and on soil reinforced with different GSN placed at varying depths of D/5, 2D/5, 3D/5 and 4D/5 from top of soil (D is the total depth of soil), to determine the ideal depth of placement of GSN within SHF and SLF. Soaked CBR (S-CBR) test was carried on unreinforced soil and on soil reinforced with different GSN placed at an ideal depth determined from U-CBR test. Based on the experimental results, ideal depth of placement of GSN for SHF and SLF was found to be D/5 and 3D/5 respectively from top of the soil and Geogrid was found to be the best geosynthetic for reinforcing the granular soil containing high fines and less fines.

УРОЖАЙНОСТЬ КАРТОФЕЛЯ СОРТА КАВАЛЕР В ЗАВИСИМОСТИ ОТ СРОКА, СПОСОБА И ГЛУБИНЫ ПОСАДКИ В ЛЕСОСТЕПНОЙ ЗОНЕ ЧЕЛЯБИНСКОЙ ОБЛАСТИ

The yield of potatoes of the Kavaler variety in the northern forest-steppe zone of the Chelyabinsk region in the period 2020-2022 largely depended on the weather conditions of the growing season (factor contribution – 15%), planting time (52%), seed placement depth (11%), somewhat less – on the method of planting (4.2%) and the interaction of factors " year” and “planting depth” (7.2%). According to the years of research, the planting time had the greatest influence on the yield, which determines 79% of the variation in 2020, 38% in 2021 and 65% in 2022, as well as the method of planting potatoes, which controlled 6.5%, 11.4%, and 4.0% respectively of the total variation of this trait. A significant effect of the depth of planting seed tubers on the yield of potatoes was noted only in the dry conditions observed in 2021 (factor contribution of – 44.4%). The potatoes achieved high yields due to the well timed planting (May 10-12th). The Kavaler variety exhibited an average productivity of 25.04 t/ha over a three-year period, showing a 4.11 t/ha increase in yield compared to the late planting dates (June 5- 6th). Ridge planting was more advantageous in the conditions of 2020 and 2022, whereas in the dry year of 2021, flat planting proved to be more effective.

Effect of implant placement depth on bone remodeling on implant-supported single zirconia abutment crown: A 3D finite element study.

This study aimed to evaluate the influence of subcrestal implant placement depth on bone remodeling using time-dependent finite element analysis (FEA) with a bone-remodeling algorithm over 12 months. Seven models of different subcrestal implant placement depths (0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm) were analyzed using FEA to evaluate the biomechanical responses in the bone and implant, including von Mises equivalent stress, strain energy density (SED), and overloading elements. SED was used as a mechanical stimulus to simulate cortical and cancellous bone remodeling over the first 12 months after final prosthesis delivery. The highest increase in cortical bone density was observed at Depth 1.5, whereas the lowest increase was observed at Depth 3.0. In contrast, the highest increase in bone density was observed at Depth 3.0 in the cancellous bone, whereas the lowest increase was observed at Depth 0. The highest peak von Mises stress in the cortical bone occurred at Depth 2.5 (107.24 MPa), while that in the cancellous bone was at Depth 2.5 (34.55 MPa). Notably, the maximum von Mises stress values in the cancellous bone exceeded the natural limit of the bony material, as indicated by the overloading elements observed at the depths of 2.0, 2.5, and 3.0 mm. Greater bone density apposition is observed with deeper implant placement. An implant depth of more than 1.5 mm exhibited a higher maximum von Mises stress and greater overloading elements.

Ex Vivo Evaluation of a Pressure-Sensitive Device to Aid Big Bubble Intrastromal Dissection in Deep Anterior Lamellar Keratoplasty.

To develop and perform ex vivo testing for a device designed for semiquantitative determination of intracorneal dissection depth during big bubble (BB) deep anterior lamellar keratoplasty. A prototype device connected to a syringe and cannula was designed to determine depth of intrastromal placement based on air rebound pressure emitted by a software controlled generator. Ex vivo testing of the device was conducted on human corneas mounted on an artificial anterior chamber in three experiments: (1) cannula purposely introduced at different depths measured with anterior segment optical coherence tomography, (2) cannula introduced as per the BB technique, and (3) simulation of the BB technique guided by the device. A positive pressure differential and successful BB were observed only when the cannula was positioned within 150 microns from the endothelial plane. In all successful BB cases (21/40), a repeatable increase in tissue rebound pressure was detected, which was not recorded in unsuccessful cases. The device was able to signal to the surgeon correct placement of the cannula (successful BB) in 16 of 17 cases and incorrect placement of the cannula (unsuccessful BB) in 8 of 8 cases (94.1% sensitivity, 100% specificity). In our ex vivo model, this novel medical device could reliably signal cannula positioning in the deep stroma for effective pneumatic dissection and possibly aid technical execution of BB deep anterior lamellar keratoplasty. A medical device that standardizes big bubble deep anterior lamellar keratoplasty could increase the overall success rate of the surgical procedure and aid popularization of deep anterior lamellar keratoplasty.

Soil arthropod responses to subsoil manuring in irrigated vegetable and rainfed grain production

Diverse soil biology is being increasingly recognised as important for productive soils. Subsoil manuring – the process of placing organic materials underground using a modified deep ripper – has been used to improve the structure and productivity of texture contrast soils. Using soil arthropods as indicator species, this study investigated the soil biology responses of the subsoil manuring approach. Different organic materials were placed in the upper zone of a clay subsoil at field sites used for irrigated vegetable and rainfed grain production. Soil samples were taken from the topsoil and from the depth of organic material placement and processed to extract soil arthropods. Of three suborders of soil arthropods recorded, mesostigmatid mites showed the most notable increases in abundance in response to subsoil manuring. The placement of organic materials at depth resulted in elevated abundance of soil arthropods at depths that are not the normal habitat of these organisms. Abundance and richness were both suppressed under irrigated production compared to rainfed, although it is acknowledged that a number of management practice differences between the two production systems could contribute to the differences observed.

Effect of Using Plastic Waste Bottles on Soil Response above Buried Pipes under Static Loads

Development and population growth have made using shallow buried pipes in urban areas, highways, and subways inevitable. In this study, the performance and behavior of shallow unplasticized polyvinyl chloride (uPVC) pipes buried in sand reinforced with PET (polyethylene terephthalate) bottles produced by the end consumer filled with soil under static loads were investigated. The bottle reinforcement mattress filled with soil was vertically installed above the buried uPVC pipe inside the soil bed at the required depth; after that, backfilling was performed. The effects of the relative density of soil, placement depth, and the width of the soil-filled bottle-reinforced block were examined. The increase in relative density has shown a noticeable decrease in footing surface settlement and load transferred to the buried pipe. The test results have shown significant improvement in the ultimate bearing capacity of bottle-reinforced soil with a reduction in surface settlement. The backfill reinforced with soil-filled bottle block has shown a 71% improvement in ultimate bearing capacity. Additionally, the improvement in bearing capacity increases as the placement depth decreases and width increases. The optimum depth of placement and width of the bottle-reinforced mattress were 0.50 and 2.08 B. The proposed soil reinforcement method may be a good and relatively inexpensive alternative to traditional geosynthetic reinforcement while providing geotechnical and environmental benefits.

Drones and Bathymetry Show the Importance of Optimal Water Depth for Nest Placement Within Breeding Colonies of Western and Clark’s Grebes

Drones and Bathymetry Show the Importance of Optimal Water Depth for Nest Placement Within Breeding Colonies of Western and Clark’s Grebes

Fertilization depth effect on mechanized direct-seeded winter rapeseed yield and fertilizer use efficiency.

Deep fertilization is effective for improving crop yield and fertilizer use efficiency. However, its impact on mechanized direct-seeded rapeseed and the optimal fertilization depth are poorly understood. A field experiment was conducted to evaluate the fertilization depth effect on mechanized direct-seeded rapeseed growth. Five treatments were designed: surface broadcast fertilizer, no fertilization, and fertilizer banded placement at soil depths of 5 (D5), 10 (D10), and 15 cm (D15). Compared with surface broadcast fertilizer, deep fertilization generally increased seed yield and partial factor productivity by 11.0%, agronomic efficiency (AE) by 22.7%, and recovery efficiency (RE) by 79.2% due to the increase of root mass density (16.8%), plant height (8.6%), height of the first branch (10.6%), stem diameter (22.4%), shoot biomass (16.1%), and shoot nitrogen (35.7%), phosphorus (29.7%), and potassium (26.2%) uptake. D10 had the highest seed yield, oil yield, fertilizer use efficiency, and economic benefits at different fertilization depth treatments. Compared with D5 and D15 respectively, D10 increased seed yield by 5.4% and 46.0%, oil yield by 7.7% and 50.5%, partial factor productivity by 5.4% and 46.0%, AE by 9.0% and 99.5%, RE of nitrogen by 48.9% and 34.9%, RE of phosphorus by 83.1% and 38.0%, and RE of potassium by 57.5% and 32.5%. The economic benefits of D10 were CNY 867.31 ha-1 and CNY 4864.23 ha-1 higher than D5 and D15 respectively. Considering rapeseed growth and its economic benefits, this study shows that 10cm is an appropriate placement depth with regard to mechanized direct-seeded winter rapeseed production. © 2022 Society of Chemical Industry.

ПОЛЕВЫЕ ИССЛЕДОВАНИЯ СОШНИКА ЗЕРНОВОЙ СЕЯЛКИ С ШАРНИРНЫМ СОЕДИНЕНИЕМ НАПРАВИТЕЛЯ СЕМЯН И РЫХЛИТЕЛЯ ПОЧВЫ С КОРПУСОМ

The uniformity of seed distribution along the length and depth of the row (sowing spacing) depends on the correct operation of the opener of the grain seeder, but not all modern openers have these indicators, so the scientists of the Penza State Agrarian University developed a grain seeder opener with a hinged connection of the seed guide and soil cultivator with the opener body, using which solves this problem. The distribution of seeds of spring barley variety "Sursky Favorit" by the depth of placement when using the developed coulter, compared with the indicators obtained using a standard double-disk coulter, was studied in the course of laboratory and field tests. According to the obtained graphic dependence, which characterizes the distribution of seeds according to the depth of placement depending on the type of coulters, it was found that the number of seeds in a given layer is 4-6 cm when sowing with a coulter of a grain seeder with a hinged connection of the seed guide and soil ripper with the coulter body and a standard double-disk seeder coulter SZ-5.4 is 91% and 71%, respectively. A decrease in the uneven distribution of seeds along the depth of the furrow will occur when using an experimental coulter, which in turn will affect the increase in yield. Yields will increase by 12% on average compared to the standard coulter.

Optimizing urea deep placement to rainfall can maximize crop water-nitrogen productivity and decrease nitrate leaching in winter wheat

The deep placement of urea fertilizer is considered an effective strategy for crop growth and yield formation. How crop root morphology and resource utilization respond to altered rainfall amount and deep urea fertilizer placement is still not fully understood. Thus, we conducted a two-year field experiment in the semi-humid region to assess the effects of different urea fertilizer placement depths of 5 cm (D5, conventional surface fertilization), 15 cm (D15), 25 cm (D25), and 35 cm (D35) under three rainfall conditions (dry year = 125 mm, P125; normal year = 200 mm, P200; wet year = 275 mm, P275) on root distribution, resource utilization and yield of wheat. Deep urea placement significantly increased root length density and root weight density in the 20–60 cm soil layer, which caused a significant increase in wheat nitrogen (N) uptake. Compared with D5, deep urea placement significantly increased the crop N uptake (10.4–27.6 %), grain N content (1.2–18.7 %), N recovery efficiency (NRE, 0.9–16.7 %) and N partial productivity (PFPN, 1.1–20.0 %) in dry and normal years, and D15 promoted those by 0.9 %, 1.3 %, 3.7 % and 1.1 % over D5 under wet year. Additionally, compared with D5, deep urea placement increased crop water productivity (WP) and yield by 9.6–23.9 % and 3.2–20.0 % under dry and normal years, and D15 increased those by 1.1 % and 0.5 % in wet year. The accumulated nitrate contents in the 0–100 cm soil layer was 4.7–14.5 % higher under deep urea placement than D5. Placement of urea at depths of 28.0–30.0 cm, 20.7–21.6 cm and 12.3–13.1 cm in the dry, normal and wet years maximized the wheat yield, grain N content and WP. Moderate deep urea placement according to variable precipitation conditions can be an effective fertilizer management strategy for sustainable wheat development.

Leveraging Coiled Tubing Conveyance in an Integrated and Rigless Abandonment and Perforation Workflow

Summary In Ecuador, shutoff of an underperforming interval through plug and abandonment (P&A) and perforation of a new interval are traditionally completed with a combination of wireline (WL) and tubing conveyance. An alternative method using enhanced coiled tubing (CT) is presented here; it enables a rigless and efficient workflow that leverages real-time downhole data for on-the-fly optimization. The new workflow relies on CT-conveyed technologies without requiring any additional conveyance methods. CT delivered four different services to start the abandonment by anchoring a 7-in. cast-iron bridge plug (CIBP), complete the abandonment with a low-viscosity cement plug, simulate wellbore dynamics during nitrogen pumping to generate the required underbalanced conditions for perforating, and perforate with a 40-ft ballistic payload of 4 1/2-in. guns. Coupled with real-time downhole telemetry, the enhanced CT workflow provided critical downhole conditions, including fluid levels, accurate depth placement and control, bridge plug setting confirmation, underbalanced conditions, perforating head activation and detonation, and postperforation inflow monitoring. Compared with traditional methods, the enhanced CT workflow introduces several benefits toward completing P&A of old intervals and perforation of new ones. These benefits include enabling a rigless workover (WO) intervention, eliminating the need and cost of a WO rig, reducing operational duration by 13%, and potentially reducing asset footprint and field crews by 95 and 70%, respectively. Elimination of a WO rig reduces environmental impact and the number of personnel on location (i.e., risk). The workflow also extends the reach and efficiency of the service in horizontal wells, enables underbalanced perforation, and delivers actionable real-time downhole data. These data elevate traditional P&A workflows and create a step change in efficiency. First, they allow tracking key downhole parameters that help guarantee a reliable operation of each of the tools and services. Second, they provide insights into the actual downhole conditions throughout the intervention to enable the operator and the field crews to make on-the-fly decisions to deliver a safe and optimal service. Those decisions may include fine-tuning the prescribed treatment or extending the scope of the intervention by leveraging the CT’s pump-through capabilities to maximize well performance and meet, or exceed, the operator’s objectives. The innovative combination of real-time telemetry with abandonment and perforating technologies proved a step change in operational efficiency and range, fueled by the quantity and quality of data recorded during the operation. This case study also marks the first documented perforation with 4 1/2-in. guns with fiber-optic real-time downhole telemetry. Furthermore, the integrated, rigless solution provides operators with an opportunity to extend their WO activity pipeline and free up their WO fleet for other activities.

Simple Formula for pH/Impedance Probe Positioning in Children-Time to Update Standard Practice?

To develop a novel formula for pH probe placement with adequate accuracy. Children (3-18 y) undergoing pH-metry were prospectively evaluated. Their height and corrected pH probe position under X-ray (2 vertebrae above the diaphragm) was recorded and the linear-regression analysis was performed to derive a novel formula. Its accuracy was checked on an additional group of prospectively included children. The success rate of a newly developed formula was estimated and compared to the performance of previously used formulae. The difference in the suggested placement of the probe (cm from nostrils) was calculated. Based on 670 children with pH probe placed under X-ray, the following formula was developed using the linear-regression analysis: L = 0.184x + 4.4 (cm) (L = probe placement depth, x = body height). Its accuracy was confirmed on additional 111 children resulting in almost 85% success rate. The formula showed significant difference in the suggested placement from formulae used previously: +4.9 ± 0.8cm, +2.4 ± 0.1cm, +0.7 ± 0.6cm, +1.1 ± 0.4cm, +1.8 ± 0.3cm, +2.2 ± 0.5cm from the one by the Strobel, Moreau, Wilson, Nowak, Staiano-Clouse formulae, and the GOSH table with the calculated success rates of 1.8%, 43.2%, 65.8%, 77.5%, 65.8% and 54.1%, respectively. A table suggesting placement depth based on the body height was developed. The present formula provides 85% success of pH probe placement in children ≥ 3 y suggesting its use in routine practice. More data are needed to confirm that probe adjustment under X-ray is unnecessary.

Where the straw-derived nitrogen gone in paddy field subjected to different irrigation regimes and straw placement depths? Evidence from 15N labeling

Straw-derived N is an organic N source, that plays an important role in agroecosystems. However, quantitatively tracing the release and fate of exogenous straw-derived N in a rice-soil system amended by irrigation regime and straw placement depth is poorly understood. The objectives of this study were to determine the release and fate of straw-derived N in the rice-soil system under different irrigation regimes and straw placement depths. 15N-labeled rice straw was used for two consecutive years in a field experiment in Northeast China, and four treatments were established: (i) controlled irrigation + shallow straw return (5 cm depth, CSD1); (ii) controlled irrigation + deep straw return (15 cm depth, CSD2); (iii) flooded irrigation + shallow straw return (5 cm depth, FSD1); and (iv) flooded irrigation + deep straw return (15 cm depth, FSD2). We found that the temporal patterns of straw N release were best described by the one-pool model, which was helpful to predict the straw-derived N fluxes during straw decomposition under different irrigation regimes and straw placement depths. Controlled irrigation and shallow straw placement depth increased the straw N release rate, which was consistent with their effects on straw mass loss, especially in the first rice season, showing a decreasing order of CSD1 > CSD2 > FSD1 > FSD2. Irrigation regime and straw placement depth significantly affected the fate of straw-derived N in the rice-soil system. Controlled irrigation will not only increase plant utilization rates of straw-derived N at different straw placement depths but also promote soil sequestration of straw-derived N and reduce the loss of straw-derived N. Additionally, we also found that placing straw at a shallower depth can also increase straw-derived N utilization by plants. Coupling controlled irrigation and placing straw at a shallower depth (CSD1) resulted in the highest utilization of straw-derived N by plants. However, it is worth noting that placing straw at a shallower depth also increases the loss of straw-derived N, which may increase the risk of environmental pollution in a soil-rice system. This study expanded the theory of straw N release and effective utilization in agroecosystems, which is helpful to better predict gross N fluxes and fates of straw-derived N in the agroecosystem to formulate a scientific and reasonable mode of field management with straw return.

The Sensitivity Analysis of the Drainage Unsteady Equations against the Depth of Drain Placement and Rainfall Time at the Shallow Water-Bearing Layers: A Case Study of Markazi Province, Iran

This research investigated various drainage parameters for unsteady conditions, including depth of installation, reflection coefficient, and depth of water table. For this purpose, Bouwer & Van Schilfgarrd, Dumm, Glover, Hemmad, and Bouwer equations were used. For the distance of computed drainage compared with measured data in central Iran, the results showed that the Bouwer & Van Schilfgaarde equation is better than others. Additionally, the installed depth was obtained 130 cm below the exiting underground, and this depth was applicable more than other depths; 1, 3, and 5-day precipitation were used to determine water table changes. The results illustrated that a 5-day duration had a better effect, which appeared in the existing condition drainage area. The reflection coefficient for the superior equation was also obtained as 0.65, which was very close to the measured data in the area. Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), and Standard deviation (σ) were used to evaluate the results. MAE, RMSE, and σ were computed as 1.78, 2.02, and 0.02, for the superior equation respectively, and the appropriate distance between the two drains was determined as 51.26 m. The obtained results have a close agreement with other researchers in this regard.

Numerical investigation of geothermal pavements: Design optimisation & boundary conditions

Geothermal pavements comprise a newfound type of thermal geo-structures, an innovation in pavement construction contributing to ground source heat pump (GSHP) systems, resulting in a better cost-efficiency compared to conventional GSHP systems. Ground heat exchangers are formed by embedding pipe into the pavement structure (e.g., base, sub-base or subgrades). Developing accurate models with appropriate boundary conditions is crucial to obtaining a deep understanding of the performance and function of geothermal pavement systems. This paper introduces an experimentally validated 3D finite element model (FEM) and compares the effect of surface boundary condition choices on the results of the simulation. The model uses two different approaches for boundary conditions: i) using ambient temperature and ii) implementing energy balance equations on the surface, as surface boundary conditions. The model is further utilised to perform a parametric study and the results are employed by a statistical tool (Minitab) to determine the optimum heat exchanger design for a geothermal pavement project in Adelaide, an Australian city subjected to temperate climate conditions and good solar irradiation throughout the year. Results show that the choice of both boundary conditions leads to similar fluid temperature trends, but with differences in values, particularly during the heating season, resulting in a reduced embedded pipe length of up to 30 % and up to a 10 % better annual average coefficient of performance (COP(when using the energy balance equations on the surface. The parametric study shows that the system annual COP increases with the length of the pipe and spacing between the pipes, whilst the pipe depth placement is inversely proportional to the annual average COP given the advantages obtained during the heating season over the cooling season. Finally, considering the interaction effect between various parameters, a pipe heat exchanger with 400 m length, 0.76 m pipe spacing and 0.45 burial depth is evaluated as the best design to maximise COP for the case study at hand.

Cyclic behaviour of stratified soil under liquefied states

A substantial amount of work on the cyclic behaviour of cohesionless soil has been performed after neglecting the reality of stratification existing nearby marine structures or alluvial plains. This complicated mechanism of stratified soil failure on earthquake-induced soil liquefaction is affected significantly by the presence of a less permeable soil layer. Several past studies investigated that under the action of dynamic loads, the presence of a silt layer in homogeneous sandy soil crucially modifies the pore pressure dissipation characteristics, axial strain rate and stress–strain behaviour of the whole stratified specimen. In the present study, cyclic behaviour of sand specimen interlayered with silt layer has been presented in respect of its pre-and post-liquefaction behaviour. Undrained stress-controlled cyclic triaxial tests have been performed on homogeneous sand specimens and on specimens interlayered with a silt layer, placed at H/4, H/2 and 3H/4 (where H is the height of the specimen from the top) to signify the role of placement depth. The instability and failure of such specimens have been compared using the failure line and phase transformation line. Few key observations suggested that the number of liquefaction failure cycles enhanced two times and secant modulus (under post liquefied state) improved by 4.8 times when the placement depth of the silt layer increased from H/4 to 3H/4 under similar loading conditions. Additionally, the role of initial static shear stress has been investigated at three different confining pressures in a few stratified specimens. It has been observed that failure of the stratified specimen is due to the obstruction of pore water movement caused by the presence of the silt layer. A comparison of the present work has been made with significant studies using liquefaction resistant curves to ensure the efficacy of this study.

Study on Influencing Factors Analysis of Gastric Tube Insertion Length and Construction of Estimation Method.

BackgroundInfluenced by individual differences, the depth of gastric tube placement is often different. Clinically, it is necessary to seek a simple and accurate gastric tube insertion scheme to improve the clinical efficacy of indwelling gastric tube.Materials and MethodsA total of 100 adult patients undergoing transesophageal manometry via nose were included in the study. The in vivo length (NCL) of apex-cardia was measured. At the same time, we entered our institutional database, summarized the clinical data of 100 patients, and analyzed the risk factors affecting NCL using stepwise regression analysis.ResultsThe NCL length scores of patients with different gender, age, marital status, height, weight, BMI, sitting height, sternum length, hairline-xiphoid process, nose tip-earlobe-xiphoid process and earlobe-xiphoid process were statistically significant (P < 0.05). Height, sitting height, gender, BMI and earlobe-xiphoid process were the factors that affected the NCL length score (P < 0.05). The prediction equation of the estimation method of gastric tube insertion length was as follows: NCL length score = 39.907 + 2.909× height +0.865× sitting height. Adjust R2 to 0.506. NCL was positively correlated with height and sitting height. Among them, the correlation with height (r = 0.711, P < 0.001) and sitting height (r = 0.397, P < 0.001).ConclusionHeight, sitting height, gender, BMI and earlobe-xiphoid process were the factors that affected the score of NCL length. There was a significant positive correlation between height, sitting height and NCL length. On this basis, the length of nasogastric tube insertion could be estimated.