Rise Height Research Articles

Case study: On hydrological function improvement for an endemic plant habitat in Gangcheon wetland, Korea

Wetlands are one of the most important ecosystems for the biodiversity of plants and animals. Especially, Gangcheon wetland in NamHan river, Korea is a very valuable one because Aster altaicus var. uchiyamae, which is one of endemic plants is inhabited. However, Gangcheon wetland was impaired by a river improvement project called ‘Four Major Rivers Project’. After the project, Gangcheon wetland restoration work was performed, for the rehabilitation of wetland functions but the habitat of Aster altaicus var. uchiyamae could not be restored. Actually, Aster altaicus var. uchiyamae can grow in a habitat made by mixing of gravel and sand from flood inundation of the river but there was no inundation after the project because of the rise of levee height. Therefore, this study evaluated wetland functions using Hydrogeomorphic(HGM) approach and analyzed flood inundation using HEC-GeoRAS model after the project for diagnosis of the functions and the habitat. Then we proposed a plan to improve the functions of Gangcheon wetland as a habitat for Aster altaicus var. uchiyamae. The reference wetland is Gangcheon wetland before the project and the wetland functions after the project were compared with the reference one. As a result of the function assessment, hydrological, biogeochemical, and plant habitat functions were deteriorated. The study wetland has three zones of A, B, and C for Aster altaicus var. uchiyamae habitats and particularly, hydrologic functions for zone C which is poor as the habitat should be improved. In particular, the habitat of Aster altaicus var. uchiyamae was adversely affected by the decrease in inundation depth and water level of the river. These hydrologic functions should be improved and the levee height be lowered for obtaining more proper habitat of Aster altaicus var. uchiyamae. This suggestion might be helpful for establishment of the habitat of Aster altaicus var. uchiyamae. Also, it could be expected that the overall function of Gangcheon wetland will be improved because biogeochemical and plant habitat functions are rehabilitated by the improved hydrological function.

Mathematical modeling and numerical investigation of density wave instability of supercritical natural circulation loop

In present paper, a mathematical model based on the one dimensional nonlinear mass, momentum and energy conservation equations has been developed to study the density wave instability (DWI) in horizontal heater and horizontal cooler supercritical water natural circulation loop (HHHC-SCWNCL). The one dimensional nonlinear mass, momentum and energy conservation equations are discretized by using finite difference method (FDM). The numerical model is validated with the benchmark results (NOLSTA model). Numerical simulations are performed to find the threshold stability zone (TSZ) and draw the stability map for natural circulation loop. Further, effect of change in diameter and riser height on the density wave instability of SCWNCL has been investigated.

ГИДРАВЛИЧЕСКОЕ ОБОСНОВАНИЕ РАБОТЫ УСТРОЙСТВА ДЛЯ НАМЫВА УЗКОПРОФИЛЬНЫХ ДАМБ

The construction of protective dams is the most effective means of combating flooding. There are various ways to build protective dams. The alluvial method of constructing protective dams can significantly reduce the cost of their construction. The article describes a method and device for alluvial narrow-profile dams that allows the use of bottom sediments as a building material. The method includes clearing the riverbed from bottom sediments with dredging operations,improving the fl ow capacity during floods. The work is carried out by a dredger and the developed soil in the form of pulp is delivered to the alluvial device. The alluvial device ensures the separation of large fractions of soil from the general flow of pulp and allows the formation of a narrow-profile dam with stable slopes and an antifiltration core. The article offers hydraulic calculations that allow us to justify the design and technological parameters of the method and device for alluvial narrow-profile dams: the values of the fl ow rate and the average speed of the pulp movement in the distribution unit of the device are determined; the dimensions of the inlet opening of the bell are justified; the time of alluvium of one map is determined; the number of outlet openings in the distribution slurry pipelines is justified and their location is specified. Nomograms are constructed that allow us to determine the optimal modes of alluvial dams – the length of the pulp pipeline, the height of the pulp rise, and the time of fi lling the alluvial map.

Study on Hydrodynamic Characteristics of Wind Turbine Monopile under Nonlinear Wave

As wind power technologies become maturer, the monopile foundation of offshore wind turbine is widely used because of its simple structure, few occupied space and low cost. However, under severe sea conditions, the impact of nonlinear wave load applied against the monopile foundation on the system structure safety cannot be ignored. In this paper, the 5MW offshore wind turbine of the National Renewable Energy Laboratory (NREL) was taken as the research object, and the computational fluid analysis software ‘STARCCM +’ was used to study the hydrodynamic characteristics of the monopile foundation of the wind turbine under different wave parameters. This paper mainly analyzed the upper wave, pressure and wave forces around the monopile foundation of the wind turbine under the same period and different wave heights. And the wave force calculated by CFD was compared with the result based on potential flow theory. The research results showed that with the rise of wave height, the upper wave, pressure and wave force around the monopile foundation increase continuously, and the second-peak phenomenon appeared at some measuring points on the water surface of the monopile foundation. Because the CFD method considers the fluid viscosity and is more in line with the real sea conditions, it is more accurate to obtain wave forces based on this method.

A distance-based capillary biosensor using wettability alteration.

Distance-based detection methods with a quantitative readout are of great significance to point-of-care testing (POCT), are low-cost and user-friendly, and can be integrated into portable analytical devices. Here, we submit a visual quantitative distance-based sensor by capillary force alteration in a capillary tube. This sensor converts the wettability alteration caused by the target molecules into a capillary rise height signal. Moreover, the sensor profits from isothermal amplification technology, achieving the detection of miRNAs with high sensitivity and specificity by visually reading the height of the water in the capillary tube. The proposed biosensor shows great potential in routine clinical diagnosis as well as POCT in resource-limited settings.

Assortative Marriage for Height–BMI in an Israeli Sample

Numerous studies have demonstrated that in western societies women are perceived as more attractive with weight drop (proxied by the BMI measure, where BMI =, while men are perceived as more attractive with height rise. The objective of this study is to test the hypothesis that as BMI rises for a woman, she has to compromise and marry shorter men. The study is based on the 2016 wave of the Israeli longitudinal survey. We observe the cross-sectional correlation between the married couples' height, weight, BMI, age, number of children, and proxies for accumulated wealth. The first part of the analysis tests the research hypothesis directly, while the second part of the analysis adds control variables. Research findings support the research hypothesis. Under equal conditions, the projected drop in the height of the male’ corresponds to an increase in the female’s BMI and age. Moreover, research findings may support the conclusion that taller men are more successful. The outcomes suggest positive association between the height of the men, and owning a car, having children, and living in a single family detached unit.

Prediction of capillary suction in porous media based on micro-CT technology and B–C model

Abstract Moisture variation in porous media depends mainly on the pore characteristics. This article used the micro-computed tomography (micro-CT) (a non-destructive imaging technique to generate a three-dimensional virtual model) and the Brooks–Corey model to deduce the moisture migration in sand. Relationship between capillary rise height and time (h–t) was achieved by numerical simulation in the capillary suction process, where the parameters fractal dimension, porosity, and air–water interfacial area were obtained by the micro-CT scanning. Meanwhile, experiments of capillary rise in sand column were performed using four different sizes washed sand, and the capillary heights at different times were recorded. Results show that the capillary suction is decided by the aperture size and phase morphology simultaneously, and particle size has obvious effect on capillarity, and the wetting front lowers with the increase in grain size and the decrease in rising rate. Parameters air entry pressure and pore-size distribution index obtained by micro-CT scanning technology and empirical formula are accurate. Method of combing micro-CT images and Brooks–Corey model can predict well the capillary suction of porous media. It is also proved that the capillary suction is decided by the aperture size and phase morphology simultaneously.

Vertical Round Buoyant Jets and Fountains in a Linearly, Density-Stratified Fluid

Turbulent round buoyant jets and fountains issuing vertically into a linearly density-stratified calm ambient have been investigated in a series of laboratory experiments. The terminal (steady-state) height of rise and the mean elevation of subsequent horizontal spreading have been measured in positively buoyant jets (at source level), including pure momentum jets and plumes, as well in momentum-driven negatively buoyant jets (fountains). The results from experiments confirmed the asymptotic analysis that was based on dimensional arguments. The normalized terminal height and spreading elevation with respect to the elevation of injection of momentum-driven (positively) buoyant jets and fountains attained the same asymptotic values. The numerical results from the solution of entrainment equations, using an improved entrainment coefficient function, confirmed the results related to buoyancy dominant flows (plumes), while their predictions in momentum-driven flows were quite low if compared to measurements.

The calculating model of microstructured flat plate wettability during evaporation into the stagnation flow

The results of the analysis of the problem of wetting the microstructured flat wall surface during adiabatic liquid evaporation into a boundary layer of air flowing at right angles are presented. The basic conservation laws are formulated in the form of differential equations that allow calculating the velocity and height of liquid rise in capillaries, wetting dynamics, depth and mass of the liquid in capillaries, and the evaporation surface area.

Relationship Between Capillary Water Absorption Value, Capillary Water Absorption Speed, and Capillary Rise Height in Pyroclastic Rocks

The existence of water is one of the most effective factors in deterioration of natural building stones. In the process of deterioration, capillary water absorption is the most significant procedure of water penetration into the building stones. Pyroclastic rocks have been widely utilized as building stone especially in historical buildings and monuments since ancient times in the Central Anatolia in Turkey. Nowadays, this type of rocks is used in the restoration of historical buildings as well as in the construction of modern buildings. Pyroclastic rocks are highly susceptible to deterioration process. Capillary rise has a significant influence on water penetration into building stones. Therefore, it is quite important to identify the factors affecting the values of capillarity, capillary rising speed, and capillary rise that define capillary water absorption in these rocks. To this end, pyroclastic rock samples in different textures were compiled from the Cappadocia region, in Central Anatolia. First, petrographic, mineralogical, geochemical, physical, and pore diameter distribution properties of the samples were determined in the laboratory. Then, capillarity values with capillary rise and capillary rise speeds dependent on time were established. Based on the data obtained, correlation coefficients between matrix percentage and capillary water absorption rate and capillary rise values of pyroclastic rocks were calculated and found to be as 0.850 and 0.891, respectively. Thus, the article proposes a new empirical equation to practically calculate the capillary rise value depending on the matrix percentage (MP) and median pore diameter (MPD) values.

Combining SfM Photogrammetry and Terrestrial Laser Scanning to Assess Event-Scale Sediment Budgets along a Gravel-Bed Ephemeral Stream

Stream power represents the rate of energy expenditure along a stream reach and can be calculated using topographic data acquired via structure-from-motion (SfM) photogrammetry and terrestrial laser scanning (TLS). This study sought to quantitatively relate morphological adjustments in the Azohía Rambla, a gravel-bed ephemeral stream in southeastern Spain, to stream power (ω), critical power (ωc), and energy gradients (∂ω/∂s), along different reference channel reaches of 200 to 300 m in length. High-resolution digital terrain models (HRDTMs), combined with ortophotographs and point clouds from 2018, 2019, and 2020, and ground-based surveys, were used to estimate the spatial variability of morphological sediment budgets and to assess channel bed mobility during the study period at different spatial scales: reference channel reaches (RCRs), pilot bed survey areas (PBSAs), and representative geomorphic units (RGUs). The optimized complementary role of the SfM technique and terrestrial laser scanning allowed the generation of accurate and reliable HRDTMs, upon which a 1-D hydrodynamic model was calibrated and sediment budgets calculated. The resulting high-resolution maps allowed a spatially explicit analysis of stream power and transport efficiency in relation to volumes of erosion and deposition in the RCR and PBSA. In addition, net incision or downcutting and vertical sedimentary accretion were monitored for each flood event in relation to bedforms and hydraulic variables. Sediment sources and sinks and bed armoring processes showed different trends according to the critical energy and stream power gradient, which were verified from field observations. During flows exceeding bankfull discharges (between 18 and 24 m3 s−1 according to channel reach), significant variations in ∂ω/∂s values and ω/ωc ratios (e.g., −15 < ∂ω/∂s < 15 Wm−3; ω/ωc > 2 for a peak discharge of 31 m3 s−1) were associated with a large amount of bedload mobilized upstream and vertical accretion along the middle reach (average rise height of 0.20 to 0.35 m for the same event). By contrast, more moderate peak flows (≤10 m3 s−1) only produced minor changes resulting in surface washing, selective transport, and local bed scouring.

Changes of meniscus shapes and capillary rise heights under hypergravity

We investigate meniscus shapes and capillary rise heights in glass capillaries with rectangular cross sections (4 × 0.2 mm), which we modified with established coatings to generate a range of surfaces that interact differently with water. Meniscus positions and shapes are imaged while the capillaries are rotated horizontally about their longitudinal axis in order to generate centrifugal forces opposing the capillary driven fluid propagation, i.e. volumetric forces. Changing the rotational speed allows us to balance both forces thereby bringing capillary rise to a stop. In brief, we find very good agreement of the different meniscus shapes we observe over a wide range of centrifugal accelerations (up to 191 g) with two independent simulations of the scenario. In addition, we are able to precisely measure capillary rise heights in differently modified capillaries over a range of centrifugal accelerations and correlate these values. Lastly, we mention how this system will prove useful to investigate wetting phenomena on swellable surfaces, i.e. surfaces whose properties dynamically change upon fluid contact, by providing precise control over the propagation speed of the three phase contact line.

Effect of specularity co-efficient on bed hydrodynamics and heat transfer characteristics of a PCFB riser

Abstract The fluidized bed gasification and combustion process are getting attention from researchers due to its advantages such as low NOx emission and power production from waste materials. Laboratory scale study of fluidized bed gasifier and combustor is not possible due to its high instalment cost. The heat supply and temperature are also of higher magnitude. A simulation study of large-scale fluidized bed setup is a potential solution to such a problem. Hence this numerical study directs the multiphase simulation of 3D fluidized bed riser using ANSYS Fluent. The riser of 2000 mm in height and 54 mm of outer diameter is considered for numerical simulation. Air with a superficial velocity of 6 m/s and sand with 2300 kg/m3 and a mean particle size of 307 μm are considered as primary and secondary phase material for the numerical simulation. The effect of the specularity co-efficient volume fraction of air has been calculated numerically. Along with the riser height, the temperature contour indicates the distribution of temperature. When the air pressure at the inlet of the riser rises, the volume fraction of air is found to be declining. The solid mass flux increases with pressure at all values of the specularity coefficient. The maximum suspension density is found to be 892 kg/m3 for the operating pressure of 5 bar. The maximum solid mass flux is observed at 5 bar pressure for this simulation work.

Indigenous knowledge of terrace management for soil and water conservation in the Sikkim Himalaya, India

The main objective of this study was to understand the farmer’s indigenous knowledge of terrace management in the Sikkim Himalaya with reference to Rani Khola watershed. Primary data were collected through a mix of questionnaire surveys, focused group discussions, and field observations with a sample size of 300 households. Detailed documentation of the evolution of the terraces and their types, bunding material, types of risers, the relationship of slope and terraces dimensions, soil and water conservation (SWC) practices were performed. Remote sensing data was used to derive information pertaining to elevation, slope and land-use/cover of the watershed. The study reveals that dimensions and types of terraces are subjected to the elevation, slope gradient, local soil and vegetation cover. Leveled terraces were constructed on lower slopes while outward sloping terraces were more common on higher slopes. It was also observed that with the increase in slope angle, width and length of the terraces decreased. Terrace riser height was also correlated with slope; riser height unavoidably increased as slope increased. The study concludes that terraces in the study watershed are effective in reducing the slope gradient and length, and in turn helpful in trapping eroded soil, slowing soil movement and in due course reducing soil erosion and increasing agricultural productivity. It is suggested that for overall management of terraces, it needs to be combined with additional soil and water conservation practices.

Numerical analysis of influence of geometry and operating parameters on Ledinegg and dynamic instability on supercritical water natural circulation loop

In this work a numerical investigation is performed to analyze a rectangular supercritical water natural circulation loop (R-SCWNCL) from thermal-hydraulic point of view with the specific work to predict Ledinegg instability and dynamic instability in a rectangular shape supercritical water natural circulation loop using a thermal–hydraulic model which is based on nonlinear mass, axial momentum and energy conservation equations. The thermal–hydraulic (TH) model has been validated against a result available in the literature. A SCWNCL of rectangular shape is analyzed and numerical simulations are carried out to obtain a marginal stability zone (MSZ) in its operating regime and relevant system. Further parametric studies have been performed to find out the impact of loop riser height (loop height), loop diameter and system pressure on the Ledinegg instability.

Impact effects due to hot vapour bubble collapse in subcooled liquid

Collapse of a hot vapour bubble captured by subcooled water can produce a cumulative jet similar to that appearing in cavitating flows. In the context of stratified steam explosions following spreading of hot melt under a water layer, impact of the water jets can be a reason for melt splashes promoting the mixing of cold and hot liquids necessary for energetic interaction. In this work, the characteristics of the directional water flow caused by collapse of a bubble near a wall are obtained, and a correlation is given which relates the ultimate height of melt rise to the bubble parameters and droplet size. Estimates relevant to melt splashes caused by the cumulative water jet impact are presented which agree with the experimental observations available in the literature.

Do PROMIS® Biopsychosocial Measures Inform Clinical Decisions in Patients with Hallux Valgus?

CategoryBunion; Midfoot/ForefootIntroduction/PurposeThe PROMIS self-efficacy of symptom management(SE)(psychological) and satisfaction with social roles (SR) (social) outcomes when combined with the physical function(PF) and pain interference (PI) (biologic) outcomes capture a patient’s biopsychosocial status. Although PROMIS accomplishes assessments efficiently (i.e. low patient/provider burden), the clinical utility of psychosocial outcomes is questioned. Moreover, in foot and ankle studies, psychosocial outcomes are less emphasized than more routine biologic outcomes (i.e. PF and PI). Data showing strong correlations of psychosocial variables with PF and PI in foot and ankle patients would demonstrate their clinical importance. The purpose was to examine the correlation of biopsychosocial PROMIS measures and physical indicators of hallux valgus severity (Manchester Scale & foot strength) with two common biologic outcomes clinicians routinely use (PF and PI).MethodsTwenty-two (22) participants with HV attended a single session to determine degree of HV deformity, foot strength (1st MTP and heel rise height) and complete PROMIS measures. Of the 22 participants (14 no-surgery, 8 post-correction surgery), 81.8% had either a moderate (C) or severe (D) deformity using the Manchester Scale. A custom force transducer set in a jig assessed 1st MTP strength. Heel rise performance was assessed using 3D movement analysis. To examine the influence of HV deformity, two one way ANOVA’s, each comparing PF and PI of patients classified by the Manchester Scale categories. Worse PF and PI were hypothesized to be associated with moderate/severe HV. A Spearman statistic was used to assess correlations. The strength of the correlations of foot strength and PROMIS SE and SR with PF and PI were categorized as excellent (>0.7),excellent-good (0.61 to 0.70), good (0.4 to 0.6), or poor (<0.4).Results:Correlations were significant with PF and PI affirming that psychosocial variables are correlated with biologic variables. Age and BMI were significantly correlated with PF and PI with rho values in good range. Measures of strength (heel height, 1st MTP Strength) were significantly correlated in the good to excellent range; heel height and PI showing the strongest correlation (rho=-0.74, p<0.01). The correlation of SE with PF (rho=0.71, p<0.01) and PI (rho=-0.75, p<0.01) were classified as excellent (Figure 1). The correlation of SR with PF (rho=0.45, p=0.04) and PI (rho=-0.58, p<0.01) were classified as good. ANOVA analysis of degree of deformity with PF and PI showed little association; average values for categories B, C, & D all within a ½ standard deviation of the US average.Conclusion:PROMIS psychosocial outcomes showed excellent to good correlations with PF and PI outcomes suggesting these variables influence physical ability and pain. The PROMIS SE outcome, a psychologic outcome, showed excellent correlations with PF and PI similar or better than performance based tests of strength. The PROMIS SR outcome showed good correlations and therefore may have less influence with patient self-report. This data suggests provider/patient interactions focusing on SE may have stronger influence on PF/PI outcomes. Providers’ interactions should focus on building SE to improve outcomes and treatment compliance that translates into higher PF and lower PI.

Modeling and Dynamic Response of Curved Steel–Concrete–Steel Sandwich Shells Under Blast Loading

The steel–concrete–steel sandwich structures are usually composed of concrete core and face steel plates. This paper presented the dynamic response of the curved steel–concrete–steel (SCS) sandwich shells subjected to blast loading. The bolts were employed to connect the face steel plates and the concrete. Numerical model was established based on LS-DYNA and the accuracy of the modelling method was verified against existing blast test. The displacement histories, damage of concrete and energy absorption capability of the shell were obtained from the numerical calculations and discussed. Different failure modes of the curved SCS sandwich shell under various loads were obtained from numerical results, i.e., local deformation of the shell for the case of close-in detonations and buckling of steel plates for the case of far-field detonations. It was noted that the concrete debris can be restrained by the face steel plates with good ductility. Numerical results showed that the energy absorption from concrete is higher under close-in detonations on the ground. The effects of charge weight, steel plate thickness, concrete thickness and rise height on the dynamic response of curved SCS sandwich shells were also analyzed and discussed in detail. The curved SCS sandwich shell with thicker back steel plate showed better blast resistant performance. Moreover, the damage of curved shell was more serious if the rise height to span ratio (Rr-s) is beyond the range of 0.16–0.25.

Suspension pattern and rising height of sedimentary particles with low concentration in a mechanically stirred vessel

AbstractIn this study, the effects of impeller rotation speed, off‐bottom clearance, blade angle, types of solid and liquid, etc., on the suspension pattern of sedimentary particles and particle rise height in liquid were investigated with a hemispherical vessel without baffles under low particle concentration. The transition conditions of suspension pattern between regimes I and II, and regimes II and III, were observed visually, and their non‐dimensional equations were expressed with an acceptable correlation by varying the above operation factors a great deal. Here, regime I is stagnation of particles on a vessel bottom, II is partial suspension, and III is complete suspension in liquid. The non‐dimensional equation of the maximum particle rise height was also successfully obtained. The combination of the non‐dimensional equations of transition and maximum particle rise height permitted us to determine the adequate solid/liquid mixing operation conditions without collision of particles with device parts.

Influence of viscosity on energy performance and flow field of a multiphase pump

Abstract Multiphase pump is widely applied for the exploitation of oil-gas resources in off-shore platforms. It is essential to investigate the performance of multiphase pumps when handling high viscosity fluid. A three-stage helico-axial multiphase pump with working fluids under various viscosities is investigated in the present study. Both energy performance and flow fields have been discussed with different viscosities. The influences of viscosity, flow rate and blade height on the distribution of turbulence kinetic energy are analyzed. Results show that both pump head and efficiency gradually reduce with the rise of viscosity when handling high viscosity fluid. The rise of viscosity and blade height, and the decline of flow rate will lead to an increase of turbulence kinetic energy. Characteristics of partial differential equations are employed to reveal the influence of viscosity, and a theoretical model has been established to predict the influence of flow rate.