Medium Sand Research Articles

Field Evaluation of UF Filtration Pretreatment Impact on RO Membrane Scaling

Pretreatment of reverse osmosis (RO) feed water of high mineral scaling propensity was evaluated with respect to downstream RO membrane scaling, for two different feed pretreatment configurations. The pretreatment schemes included (i) media sand filtration, followed by a hydrocyclone (HC) and (ii) a hydrocyclone, microfilter, and a UF module, where both configurations included mesh screens for added protection. The first pretreatment configuration reduced the source water turbidity to ~0.5 NTU, while treatment that included UF feed yielded turbidity of <˜0.1 NTU; both pretreatment strategies provided feed water turbidity within the range recommended for RO desalination. Membrane scaling tests, with the pretreated water without antiscalant dosing, using a plate-and-frame RO unit and a membrane monitoring system, provided real-time membrane surface images that were quantified with respect to the progression of mineral scaling. RO desalting of source water pretreated with the first configuration revealed flux decline that was 75% greater and scale coverage (primarily gypsum) a factor of approximately eight higher relative to desalting of UF-treated source water. The results suggest that RO desalting of high mineral scaling propensity water can significantly benefit from added UF treatment to achieve feedwater turbidity to well below the typically recommended 0.5 NTU upper limit.

Effects of seawater on the infiltration behavior of bentonite slurry into sand

As a support fluid, bentonite slurry has been extensively used in slurry shield tunneling to stabilize the tunnel face by forming a low-permeable filter cake. However, the infiltration behavior of bentonite slurry in complex conditions such as when suffering from seawater intrusion has not been fully understood. In order to investigate the infiltration behavior and filter cake formation under seawater intrusion, seawater-based bentonite slurries with increased salt content were prepared to represent different seawater intrusion severities. The rheological properties and physical stability of these slurries were evaluated. A series of infiltration column tests were conducted on two saturated sand beds with different particle sizes. Scanning electron microscope (SEM) was performed to unravel the microstructure of the filter cake. The infiltration column test results show that the low-permeable filter cake can be formed on the fine sand bed regardless of the salt content of the slurry. The salt shortened the time span of the mud spurt and made the filter cake more permeable to water. For the medium sand, the filter cake cannot be formed when the salt content exceeds 1%, because the deterioration of rheological properties of the slurry weakened its rheological blocking effect when infiltrating the sand. Based on the SEM images, it was found that the filter cake under seawater intrusion contained many well-connected inter-agglomerate channels that reduced its sealing quality. The obtained results can provide guidance and reference for the application of bentonite slurry when tunneling in a sea environment.

Reducing the Erodibility of Sandy Soils Engineered by Cyanobacteria Inoculation: A Laboratory Investigation

Windblown and water-induced erosion cause substantial soil losses worldwide, especially for drylands. Any sustainable management program that increases soil organic matter and improves the stability of the crustal layer could considerably enhance soil productivity and the preservation of erosion-prone land. This paper presents a laboratory investigation of cyanobacteria-inoculated medium sand and fine sand soils studied for severe runoff conditions that were simulated using an erosion function apparatus (EFA). Loosely deposited sand specimens prepared by air-pluviation were inoculated with a single native filamentous-cyanobacterium strain (investigating both Nostoc sp. and Calothrix sp.) and then incubated under high exposure to white light for 32- or 48-day periods. Well-developed bio-crusts were produced on the specimens’ top surface that achieved substantial improvements in erosion resistance, as was demonstrated for a wide range of hydraulic shear stress investigated using EFA experiments. Relative improvements in hydraulic erosion resistance were explained in terms of the nature of the cyanobacteria-developed microstructures (cyanobacteria filament infiltration of pore-void spaces and exopolysaccharide excretion), as were observed by scanning electron microscope examinations. The developed microstructure depended on the cyanobacterium strain employed and the nominal pore-void sizes that are related to the sand gradation and density state. The encouraging findings of this experimental investigation suggest a tailored approach (i.e., employing a suitable native cyanobacterium strain chosen for its compatibility with the soil’s physical properties) could lay the basis for developing a novel technology for soil protection.

Vegetation–soil dynamics in an alpine desert ecosystem of the Qinghai Lake watershed, northeastern Qinghai–Tibet Plateau

Different types of dunes cause habitat differences, which can affect vegetation growth. In turn, water utilized by vegetation leads to the differential distribution of soil moisture in different dunes. However, vegetation–soil dynamics in the alpine desert of the Qinghai–Tibet Plateau remain poorly understood. We chose the largest section of desert along the eastern shore of Qinghai Lake as a study area to test the hypotheses that plant community characteristics and soil physicochemical properties show differences in different sand-binding communities, in addition to soil moisture content, based on methods of field investigations and in situ observations. The main results were as follows:1) Plant community species diversity and herb coverage increased with the stabilization status of dunes; meanwhile, coverage increased with the age of the added artificial semi-fixed dunes. 2) Surface deposits were mainly composed of medium sand, leading to low organic matter and nutrient content in the study area; this being different from other deserts in northern China. 3) Soil moisture’s seasonal variation was consistent with rainfall seasonality and lacked significant interannual differences, while its vertical distribution was influenced by precipitation infiltration. 4) Soil crust forms beneath specific species, such as leguminous plants in the study area, which should be effective at preventing wind erosion. Our findings will facilitate a mechanistic understanding of plant–soil–water relationships in alpine deserts and provide timely information for screening introduced species for enhancing sand-fixation effectiveness.

Microtextural signatures in quartz grains and foraminifera from tsunami deposits of the Portuguese shelf

This study presents results from two sediment cores collected on the southern Portuguese shelf attempting to, partially, fill the knowledge gap of the offshore record of high-energy events. The results were obtained based on description of cores, microtextural analysis of quartz grains, and foraminiferal taphonomy. The lithostratigraphy corresponds to Late Holocene sedimentation, with interesting intercalations of medium sand rich with bioclastic fragments and erosive basal contact. In terms of microtextures, a high degree of mechanical marks on the grains associated with tsunami deposition was observed and reflects the high-energy hydrodynamic processes. In compositional terms, the higher presence of quartz grains in these units favors the increase of mechanical marks because grain-to-grain contact is more intense. Additionally, the geomorphological setting of the coring sites controlled the degree and type of mechanical microtextures observed. Furthermore, post-depositional changes and characteristics of the original sediment source contribute to explain the occurrence of dissolution in units of GeoB23513-02. The foraminiferal taphonomy displayed a predominance of dissolution alteration in the test surfaces that was more evident in the silty layers. On the other hand, similar to quartz grain microtextural signature, the sandy high-energy units exhibit a slight predominance of physical processes despite the still strong presence of dissolution. The sole presence of foraminifera species from the middle to the outer shelf in some units is an indication that there was little reworking of specimens. This work aims to increase the understanding of dynamics during Holocene high-energy events and to characterize their backwash phases through the different imprints left in the sedimentary offshore record of the Portuguese Algarve shelf.

Solid Removal across the Bed Depth in Media Filters for Drip Irrigation Systems

Pressurized sand media filters are commonly used in drip irrigation systems to prevent emitter clogging. However, the performance of these filters may be improved with more information about the retention of solids at different bed depths under different filter operation conditions and irrigation water sources. In this study, experiments in a scaled sand media filter were conducted to clog the filter with two different filtration velocities (30 and 60 m h−1) and two-particle types (inorganic from A4 coarse sand dust and organic from a reclaimed effluent). The suspended solids retained in slices of 5 mm (in the first 20 mm of the bed) and 20 mm (from 20 to 200 mm depth) thick were determined following the van Staden and Haarhoff (2011) procedure. The solids retained in each slice per mass of media were significantly (p < 0.05) affected by the interaction between the filtration velocity, the bed depth, and the particle type. The solids retained in the first 5 mm of the bed were significantly higher than at other depths. Moreover, inorganic solids were retained more in upper slices than organic ones. Therefore, media depths may be adjusted depending on the irrigation water source to optimize media use.

Performance Analysis of Axially Loaded Secant Pile Wall Embedded in Sand: An Experimental Investigation

In urban environments, temporary excavation support systems (ESSs) are intensively recommended during the construction process of structures with underground levels to preserve nearby structures and maintain the excavation sides. Once the foundations and basements are constructed, these systems are rendered useless. As a result, integrating the temporary ESS into the building foundation may have significant benefits. Therefore, the main aim of this paper was to investigate the behavior of Secant Pile Walls (SPWs) through fifteen model tests with an acceptable scale on an axially loaded SPW embedded in medium and dense sand. This study considered several factors to define wall behavior, such as normalized lateral deflection (δh/Ht%), the vertical deflection of the SPW (δvw/Ht%), vertical ground settlement (δv/Ht%), and settlement influence zone (Do). These factors were investigated and analyzed under the influence of a set of parameters including normalized penetration depth (He/Hc), sand relative density (Dr), and surcharge load density (Wsur). The findings demonstrated that SPWs had structural and overall stability features to withstand lateral earth pressures as well as applied axial loads. Generally, increasing the He/Hc ratio further than a limit value of 2.0 for the same surcharge load had a limited impact on the ultimate axial capacity, particularly in the case of dense sand. The location of the pivot point (ε′) extended from 0.24 to 0.41He from the wall tip, with a mean value of 0.34He and 0.29He for the values of Dr = 80 ± 2%, and 60 ± 2%, respectively. Other issues were also discussed for selected samples, including an analysis of the wall's bending moments and any potential wall buckling. Finally, to correlate the experimental data with the theoretical values, a modification factor for the pile static formula was developed by using nonlinear regression analysis with a significant prediction accuracy with an R2 of 0.94.

The Screening of Plant Growth-promoting Rhizobacteria based on the Ability to Promote the Growth and Nodulation of Soybean (Glycine max L.) Seedlings

Plant growth-promoting rhizobacteria (PGPR), which were isolated from the plant rhizosphere, decrease the addition of chemical fertilizer (N) and promote plant growth. Some PGPR isolates can fixate nitrogen, solubilize phosphate, produce phytohormones, and control soil pathogens. This study has focused on isolating rhizobacteria from root nodules of Edamame, Glycine max L, Dieng Peanut, Solanum sp. and Peanut root. Eleven isolates were assayed to examine their activities, including the ability of nitrogen fixation, produce Indol Acetic Acid hormone, siderophore, ammonia, and catalase activity. Furthermore, 11 isolates were tested to promote soybean growth in pot experiments using sterile sand media and the test of symbiotic capacity. The results showed that six isolates (RhizE2, RhizE3, RhizE4, RhizKdKbm1, Bio2DW, and Bio3DW) could form root nodules, and four isolates (RhizE2, RhizE3, RhizKdKbm1, and Bio2DW) showed a symbiotic capacity of more than 90%. RhizE2 significantly increased the number of nodules and dry weight of the entire plant (24.08 g) in comparison with plants without inoculation and added N fertilizer (11.59 g) and added N fertilizer (19.60 g). RhizE2 can be further developed as a biological fertilizer agent, especially for soybean plants. From all parameters observed, the plants inoculated with RhizE2 showed the best growth result.

Experimental Study on Effect of Sand Grain Size and Heat Dissipation on the Properties of Moulding Sand

The rate of heat dissipation affects the solidification of the casting. A controlled cooling rate is necessary to produce defect-free castings. Sand qualities such as green compression strength, permeability, flow ability, mould hardness, and compactibility play a key role in controlled cooling or uniform heat flow across the casting. A research is executed in this paper to see how these properties affect the heat dissipation rate. The coarse grain and fine grain sand particle sizes are the most important influencing elements. The solidification time for casting in coarse, medium, and fine grains was noted in the results, and it was discovered that the cooling rate is better for coarse sand grains, as well as a relationship between solidification time and sand qualities was developed. During the experimental results it was observed that highest value of compactability was found to be 72% in case of medium sand, highest value of flowability was found out to be 87% in case of medium sand and highest value of permeability number was found in case of course sand particles i.e. 471.

Determination of groundwater potential using electrical resistivity survey and borehole logging in sites I and III of Delta State University, Abraka Nigeria

This study examines the aquifer properties and lithological structure of Abraka, Nigeria, specifically the Delta State University Site I and III environs. Ten Schlumberger geoelectric soundings, geophysical well logging and pumping test method were employed using an ABEM Terrameter. A drilled water well and existing borehole data were used for this study. The result of the lithological study revealed that the subsurface formations consist of topsoil, lateritic sand, fine and medium grain sand mixed with clay. The topsoil is brownish with thickness of 2 m, the laterite is reddish with thickness of 4 m, the fine sand is whitish with thickness of 10 m, and the medium sand is also whitish with thickness >12 m. The results of the evaluation of the geoelectric data using curve matching and Win Resist computer iteration was in strong agreement with that of the well record, with a subsurface that is composed of 4 to 6 geo-electric layers. The depth ranges from 13.5m to 97.8m while the resistivity ranges from 1021.2 Ωm to 9092.4 Ωm. A core soil sample collected at an interval of 5m, spontaneous potential and resistivity logs were carried out on the well. The hydraulic conductivity, well's transmissivity, storativity, and specific capacity are 102.7m2/day, 5.14 m/day, 0.00062 and 0.39 m3/m respectively. It is recommended that a drill depth of 30 m and above should be accessed for potable water in the area. From the result of this survey, we infer that this aquifer is confined and capable of supplying the people with adequate and good quality drinking water.

Effects of Gibberellic Acid (GA3) Application on The Plant Growth and Seed Production of Pinto Peanut (Arachis pintoi Krap & Greg)

Pinto peanut (Arachis pintoi Krap & Greg.) is a legume that is usually used as a cover crop, bio mulch in fruit and vegetable plantations, ornamental plants, and animal feed. Pinto peanut has many benefits; through the symbiosis with rhizobacteria they can fix nitrogen, as ground cover can reduce the risk of landslides, inhibit weed growths, and is a source of nectar for bees. Arahcnis pintoi can be propagated vegetatively or generatively, but generative propagation is hard to conduct in the tropics because it takes a long time for the plants to produce seeds. Our study was conducted to determine the effect of GA3 application on seed production of A. pintoi. The experiment was arranged in a single factor randomized complete block design with GA3 concentration of 0, 75, 150, 225, and 300 ppm. An orthogonal polynomial test was conducted to determine the effective concentrations for GA3 on seed formation and seed viability. Harvested seeds were stored for 1 month, then sown on sand medium; the seeds were soaked in 1% KNO3 solution to break seed dormancy prior. Our study showed that the GA3 effective concentration range from 130.69 ppm to 137.16 ppm, indicated by the increase the number of flowers at 105, 120, 135, and 150 DAT up to 28.59% compared to control. GA3 at 126.80 ppm can also increase the number of harvested pods by 18.16%. The effect of GA3 on vegetative growth was shown by the increase in the growth of new individual plants concentration, i.e. 53.25 new individual plant with GA3 application of 141.88 ppm.

Validating Agar as an Analog of Soil to Monitor Corrosion of Pipeline Steel

Aqueous electrolyte traditionally used for electrochemical characterization of soil‐related corrosion in laboratories fails to represent the soil physical features, such as pore structure, soil heterogeneity, soil compaction, and saturation levels, in the diffusion‐controlled corrosion process. This article introduces a semi‐solid agar system to reproduce the physical structure of soil for corrosion study. For feasibility validation of the agar system, direct comparison regarding electrochemical activity, diffusion characteristics, and corrosion mechanisms has been performed on pipeline steel in aqueous sodium chloride (NaCl) solution (5 g L−1), 5 g L−1 NaCl‐containing agar, and 5 g L−1 NaCl in sand, respectively. The results indicates that oxygen diffusion in agar and sand media is similar, which significantly weakens the cathodic activity of steel specimens, but leads to distinct corrosion characteristics from those identified in aqueous NaCl solution counterparts. The high diffusion rate of chloride ions in aqueous solution also accelerates corrosion of pipeline steel in NaCl solution through extensive attack at defect sites, but the limited chloride ion movement and the diminished driving force for anodic corrosion activity reduce such attack in their agar and sand equivalents. The solid nature of agar outperforms aqueous electrolytes as soil replicate to explore soil‐related corrosion responses at laboratory scale.

Light Intensity and Growth Media Influence Growth, Nutrition, and Phytochemical Content in Trachyandra divaricata Kunth

Trachyandra divaricata (Sandkool) is one of the most abundant wild edible inflorescence vegetables in South Africa. The dearth of literature on its edibility, nutrient composition, and conservation has contributed to its underutilisation. This study investigated mineral and proximate content, phytochemical compositions, and growth response of T. divaricata to light intensity and soilless media. Treatments comprised four media (LECA clay, silica sand, peat, and vermiculite) which were subjected to different shade levels (no shade, 20, 40, 60, and 80%) created from a factory-made 20% density net by doubling (40%), tripling (60%), and quadrupling (80%). All treatments were irrigated with a standard nutrient solution. The results showed that the treatments impacted the yield of T. divaricata significantly in terms of biomass and flower buds, especially in plants cultivated in peat under normal greenhouse lighting (no shade). Conversely, plants developed significantly more specific leaf size and total chlorophyll content under shade levels (20, 40, 60, and 80%) in different growth media, even though the values were comparable among treatments. The highest Ca, Mg, Cu, Fe, and Mn levels were consistently recorded in flowers of T. divaricata grown in LECA clay under 80% shade level, while other minerals varied in tested treatments. The peat medium under 20% shade optimised the neutral detergent fibre (NDF) and acid detergent fibre (ADF) content of the flowers, whereas both fat and protein contents were greatly enhanced by peat and vermiculite, respectively, under the 80% shade. Consistently, the lowest phytochemical contents were recorded in LECA clay subjected to 80% shade, whereas the highest polyphenols and DPPH antioxidants were produced by silica sand medium treated with 20% shade. Both TEAC and FRAP antioxidants were improved significantly in LECA clay under no shade and the 60% shade level. However, both 20% and 60% shade levels enhanced the flavonol content significantly. On the basis of these findings, T. divaricata is a promising inflorescent vegetable that may be considered for domestication and further research due to its potential pharmacological and nutraceutical values.

TERMITES AND Rhizoctonia sp.: MAJOR PROBLEMS IN ROBUSTA COFFEE CUTTINGS CULTIVATED ON DIFFERENT PLANTING MEDIA

Robusta coffee is one of the plantation commodities vegetative propagated through cuttings to keep them in the same characteristics as their parents. The main problems in cuttings propagation are pests and diseases are cause damage to the planted cuttings. This research aimed to study the causal agent and its damage to robusta coffee cuttings planted on different media. The research was conducted from September 2020 to March 2021 in the experimental field station (KP) Pakuwon and the Integrated Laboratory of Balittri. The arrangement of the experimental design was a split plot with two repetitions. The main plot was the type of media planted consisting of sand, sand + fertilizer (1: 1), sand + soil (1: 1), soil + fertilizer (1: 1), sand + soil + fertilizer (1: 1: 1). The subplot was a Robusta coffee clone consisting of BP308, BP393, and SA203. The results showed that the highest percentage of damage caused by termites and Rhizoctonia sp. was observed on the cuttings planted on sand + fertilizer mixture media while the lowest was on sand media. The termites found in the robusta coffee cuttings were Macrotermes gilvus.

Shear strength analysis of interfaces between granular soils and concrete cured under stress

The goal of this study was to improve the understanding of the soil-structure interaction mechanisms at the interface of bored concrete piles cast in sandy soils. In addition, this study aimed to quantify the interface shear strength and identify the factors that influence the response. Roughness measurements and direct shear tests were performed at the interface between two samples of sand (medium and coarse) and concrete cured under stress. The influence of the mean grain diameter, relative density, water content, concrete curing time and normal stress on the interface shear strength were statistically analyzed. The results showed a consistent behavior with the technical literature, but with higher values, which can be attributed to the concrete curing time, a factor not studied by other authors.

Seismically-induced down-sagging structures in tephra layers (tephra-seismites) preserved in lakes since 17.5 cal ka, Hamilton lowlands, New Zealand

We analysed numerous soft-sediment deformation structures (SSDSs) identified in seven unconsolidated, up to 8-cm thick, siliceous tephra layers that had been deposited in ~35 riverine-phytogenic lakes within the Hamilton lowlands, northern North Island, New Zealand, since 17.5 calendar (cal) ka BP. Based on sediment/tephra descriptions and X-ray computed tomography scanning of cores taken from ten lakes, we classified these SSDSs into elongated load structures (i.e., down-sagging structures) of different dimensions, ranging from millimetre- to decimetre-scale, and centimetre-long dykes. Down-sagging structures were commonly manifested as intrusions of internal tephra beds of very fine to medium sand into underlying organic lake sediments. The tephra layers commonly exhibited an upper silt bed, which was not directly affected by deformation. Dry bulk density and grain size distribution analyses of both the organic lake sediment and the internal tephra beds provided evidence for the deformation mechanism of down-sagging structures and their driving force: the organic lake sediment and the upper silt bed are less liquefiable, whereas the very fine to medium sand internal tephra beds are liquefiable. The tephra layers and encapsulating organic lake sediments formed three-layer (a–b–a) density systems, where ‘a’ denotes the sediment unit of lower density. We infer that downward-directed deformation was favoured by the a–b–a density system with the upper, less-liquefiable, silt bed within the tephra layer preventing upward intrusion during the liquefaction process. The spatial distribution and ages of SSDSs within the lakes provided some evidence that liquefaction of the older tephra layers, i.e., Rerewhakaaitu, Rotorua, and Waiohau tephras, deposited 17.5, 15.6, and 14 cal ka BP, respectively, was triggered by a seismic source to the northeast of the Hamilton lowlands (i.e., Kerepehi and/or Te Puninga faults). In contrast, the liquefaction of the younger tephra layers, i.e., Opepe, Mamaku, and Tuhua tephras, deposited 10.0, 8.0, and 7.6 cal ka BP, respectively, may have been triggered by movement on local faults within the Hamilton lowlands, namely the Hamilton Basin faults, or by distant faulting at the Hikurangi subduction margin east of North Island.

Analysis of the Influence of Water Level Change on the Seepage Field and Stability of a Slope Based on a Numerical Simulation Method

River floods, dammed lake flood discharge, reservoir discharge, seawater recession, etc. all cause the water level in front of a slope to drop, which changes the original steady-state seepage field in the soil, leading to harmful slope instability. To study this phenomenon, a numerical model was established through theoretical analysis combined with the coupling of the Seep/W and Slope/W modules of the GeoStudio finite element software, and the numerical model was verified by the model test results of indoor medium sand and silt. This paper focuses on the effects when the water level in front of a slope drops at different speeds, different drop ratios, different initial water levels, different filling materials, and matrix suction on the seepage field and slope stability. The conclusions are as follows: (1) the greater the speed at which the water level in front of a slope falls, the greater the downward seepage force formed by the seepage field of the slope to the slope body; (2) the change curve of the safety factor at a higher speed is steeper when the water level falls at different speeds, and the safety factor value when the water level in front of the slope is constant is smaller; (3) the safety factor of the slope decreases with an increase in the drop ratio; when the drop ratio is the same, the loss of stability is worse if the initial water level is lower; (4) when there is a drawdown of water levels in front of the slope, the non-cohesive medium sand slope is more prone to instability failure than the cohesive silt slope; and (5) when this modeling method is applied to matrix suction, the effect of matrix suction increases the safety factor of the slope.

Advancing the knowledge of solute transport in the presence of bound water in mixed porous media based on low-field nuclear magnetic resonance

Bound water (BW) has significant effects on the physical and chemical properties of soils and other geologic formations. However, little is known about its effect on the non-Fickian transport of solute in porous media. This paper investigated the effect of BW on the non-Fickian solute transport characteristics in mixed porous media. Different porous media of quartz sand with variable contents of powdered minerals were prepared. The low-field nuclear magnetic resonance (LF-NMR) was used to quantitatively characterise BW and its spatial distribution. Then solute transport experiments were conducted in different prepared porous media and the measured breakthrough curves (BTCs) were analysed using the advection–dispersion equation (ADE), mobile-immobile (MIM) and continuous time random walk (CTRW) models. The results revealed that all measured BTCs exhibited the characteristics of early arrival and late-time tailing. However, stronger non-Fickian characteristics were observed as BW increased in content, indicating that BW influenced the non-Fickian transport of the solute. The optimised immobile water fraction of the MIM model consistently increased with increasing estimated BW fraction. Moreover, the coefficient of mass transfer rate (α) of MIM decreased as BW increased, meaning that the solute exchange between the mobile and immobile fluids became slower and consequently yielded strongly tailed BTCs. From the CTRW model, the solute transport velocity (vCTRW) increased with increasing BW, leading to a reduction in the breakthrough time of the solute. An increase in BW yielded a decreasing power law exponent (βCTRW) of the CTRW model, implying an enhancement of the non-Fickian transport characteristics. Furthermore, the porous media with BW<16.4% showed moderately non-Fickian solute transport whereas those with BW≥16.4% exhibited highly non-Fickian solute transport.

Standardization of EF polymer as potting media for roof top cultivation of ridge gourd

The present study reports that EF polymer in potting media for rooftop cultivation of ridge gourds bestows myriads effect on growth, yield and quality in ridge gourd plants. Here in media of sand + vermicompost + EF polymer + cocopeat + vermiculite and perlite (3: 2.5: 2: 2: 0.5) had significant effect on vine length (426.5cm), number of branches per vine (14.66), early flowering (35.6 days), early picking (95 days), duration of flowering (155.67days), maximum fruit length (22.3cm), fruit diameter (4.2cm) and fruit yield (680.66gm). Similarly, it influences quality parameters such as TSS (4.2°Brix), total sugar (9.15mg/100g), protein content (1.39 mg/100g), vitamin C (4.34mg/100g), reducing sugar (6.58mg/100g), available of nitrogen (0.86%), phosphorus (0.704%) and potassium (1.87%) in leaf as compare to control. Moreover, EF polymer in potting media act as bio stimulant to stimulate the nitrogen content and influence photosynthetic efficiency in ridge gourd.

Minimizing the displacement of integrated system of wind and tidal turbines based on the soil types under cyclic loads

&lt;abstract&gt; &lt;p&gt;Hybrid offshore platforms are complex structures that need to tolerate cyclic loads. These loads occur when the turbine is working between cut-in and cut-out speeds and depend on the turbine's rotational speeds. However, selecting a proper soil for the structure to be secured in is very important for the stability of the hybrid system. This study aimed to calculate the displacement of an integrated offshore structure capable of supporting a hybrid assembly of one wind plus two tidal turbines under cyclic loads. The monopile has been found to be a suitable foundation type, as the most inexpensive solution in water depths less than 30 meters, for integrating both types of turbines. The deflection of the structure was compared for different types of soil with finite element analysis. Several simulations were conducted using OPTUM G3 software for calculating the stability of each type of soil in the rotational speed range of turbines. The results enable determining the amount of deflection for each soil type. The displacement range for soft clay is 0.0052 to 0.0098 m, and displacement is between 0.007 and 0.0158 m for medium sand. The minimum displacement of firm clay, which is 0.0115 meters at 5 rpm, is higher than all minima of other soil types. Thus, soft clay and medium sand show more stability, and firm clay is less stable in the rotational speed range of the turbines.&lt;/p&gt; &lt;/abstract&gt;