Effect Of Water Loading Research Articles

Effect of water loading on the stability of pristine and defective UiO-66

Materials used for water treatment purposes need to be stable for easy handling and cost-effectiveness.

Free roll decay simulation of a polar research vessel with an anti-roll tank based on CFD

The Polar Research Vessel (PRV) must consider both icebreaking and ocean navigation performance, but its hull lines can result in large amplitude roll motion in storms. To address this issue, an anti-roll tank (ART) is fitted to restrain the roll. Using the viscous CFD method, a numerical model is established to couple ship motion with fluid motion in the ART. The simulation accurately captures the fluid motion characteristics in the ART and solves the nonlinearity of fluid motion coupled with roll motion. The study reveals the suppression rule of ART parameters on ship motion and completes the design of ART for polar icebreakers. Investigating the effects of water load, channel height, and installation height of ART on roll motion suppression using an equivalent damping evaluation method provides insight into ART parameter suppression rules on ship motion, facilitating ART design for polar icebreakers.

Surface water load and earthquake stress interactions near the Pirrís reservoir, Costa Rica

This study analyzes the relationships between the stress changes produced by the water load variations due to the filling operations at the Pirrís Reservoir, Costa Rica, and the stress changes generated by three relevant earthquakes after the first impoundment. The earthquakes differ in their magnitude, distance from reservoir and depth. Two of them correspond to a shallow crustal faulting, and the third earthquake corresponds to a subduction thrust-fault. The first filling operations began in March 2011 and the daily time history of water levels was available until December 2017. The seismicity has been recorded by a dense local network of seismological stations operating since January 2008. Effects of both types of sources (water loads and earthquakes) were combined to obtain the total Coulomb Failure Stress in the reservoir area, analyzing which of them was dominant in each case and time. We then analyzed the effects of the pore pressure diffusion due to the water loads on the nearby seismicity including two of the studied earthquakes. Results lead to different conclusions depending on the characteristics of each earthquake. An important result is observed after the occurrence of the subduction earthquake, where the coseismic effects become dominant along the entire study area, eclipsing the effect of water loading at all depths. This shows that in a regime stressed by a regional earthquake, albeit of its moderate magnitude, and regional distance, the effect of water loads is barely perceptible. In the absence of tectonic activity, however, the impact of water loading is notable.

The need for operando modelling of 27Al NMR in zeolites: the effect of temperature, topology and water.

Solid state (ss-) 27Al NMR is one of the most valuable tools for the experimental characterization of zeolites, owing to its high sensitivity and the detailed structural information which can be extracted from the spectra. Unfortunately, the interpretation of ss-NMR is complex and the determination of aluminum distributions remains generally unfeasible. As a result, computational modelling of 27Al ss-NMR spectra has grown increasingly popular as a means to support experimental characterization. However, a number of simplifying assumptions are commonly made in NMR modelling, several of which are not fully justified. In this work, we systematically evaluate the effects of various common models on the prediction of 27Al NMR chemical shifts in zeolites CHA and MOR. We demonstrate the necessity of operando modelling; in particular, taking into account the effects of water loading, temperature and the character of the charge-compensating cation. We observe that conclusions drawn from simple, high symmetry model systems such as CHA do not transfer well to more complex zeolites and can lead to qualitatively wrong interpretations of peak positions, Al assignment and even the number of signals. We use machine learning regression to develop a simple yet robust relationship between chemical shift and local structural parameters in Al-zeolites. This work highlights the need for sophisticated models and high-quality sampling in the field of NMR modelling and provides correlations which allow for the accurate prediction of chemical shifts from dynamical simulations.

Influence of water of negative oxidation-reduction potential with hydrogen saturation on kidney function in rats

Objective. To study the effect of water load of negative redox potential with hydrogen saturation on renal function in comparison with induced diuresis with water of negative redox potential without hydrogen saturation.Material and methods. In experiments on 60 male white-nonlinear rats weighing 0.16-0.18 kg, the effect of loading with ordinary tap water (redox potential 90.4 ± 1.45 mV), water of negative redox potential without saturation with hydrogen (redox potential - 304.5 ± 4.79 mV) and water of negative redox potential with hydrogen saturation 1.0 - 1.2 ppm and redox potential -297.3 ± 5.27 mV. Used: experimental, physiological, biochemical, chemical, physicochemical, statistical research methods.Results. Under water load of negative redox potential with hydrogen saturation in comparison with induced diuresis of negative redox potential with the use of microhydrin, there was no inhibition of glomerular filtration, filtration fraction and proximal reabsorption of sodium ions, change restorative potential of urine. These changes are explained by the lack of activation of the dysregulatory mechanism of basal vascular tone of the renal cortex under conditions of water load of negative redox potential with hydrogen saturation.Conclusion. Water loading of negative redox potential with hydrogen saturation in comparison with induced diuresis of negative redox potential without hydrogen saturation causes recovery of glomerular filtration rate, filtration fraction and proximal reabsorption of sodium ions, due to the lack of activation of the mechanism of basal vascular tone of the renal cortical substance, due to the high permeability of molecular hydrogen and uniform delivery of electrons to all organs and tissues.

Reliability based structural design of river–sea tankers: Still water loading effects

More than twenty years ago it was acknowledged that methods used in ship design, which affect safety of the vessel, are less sophisticated and modern compared to those used in some other industries, for instance aeronautics or nuclear. The most apparent response to this setback was enforced development of reliability based methods for ship structural design. Implementation of those in the state-of-the-art rules and codes for design of ocean-going vessels is recognizable. However, much less, if anything, was done in this matter for river-sea ships, although a significant portion of their demands and capacity is stochastic in its nature. This paper is aimed to be a pilot research in this field. It uses probability approach to estimate the reliability index of Rule based formulas for still water bending moment, i.e., the probability that thus obtained values will not be overcome by actual, lege artis calculated values. It is based on analyses of more than 400 load cases of 37 prominent river-sea tankers. Acquired results are also input parameters for further analyses, which would include wave induced loads and are the subject of succeeding investigations.

Dysregulation mechanism of the influence of water of negative redox potential on kidney function

Elucidate the dysregulatory mechanism of the effect of water load of negative redox potential in comparison with induced diuresis with ordinary tap water on the functional state of the kidneys.Material and methods. The experiments were carried out on 40 male white nonlinear rats weighing 0.16-0.18 kg with the analysis of the effect of water loading with a negative redox potential on renal function, which was obtained by treating tap water with microhydrin. The redox potential of water and urine was determined with an ORP meter. From the indicators of renal function studied: protein excretion, glomerular filtration, filtration fraction of sodium ions, its absolute and proximal reabsorption. Statistical processing of the data obtained, including multivariate regression analysis, was carried out using the Statgrafics, Statistica, and Excel 2003 programs.Results. Comparative multivariate analysis of the effect of water loading of negative redox potential in comparison with induced diuresis with ordinary tap water revealed an ambiguous nature of reliable correlations (p <0.05) between the studied indicators of renal function and the redox potential of urine, which is due to the simultaneous presence of both protective mechanisms of negative redox potential influence (improvement of energy supply, antioxidant effect), and damaging (transient renal ischemia due to activation of the basal tone mechanism due to an increase in the contractile function of the heart as a result of improving its energy supply), the final result will depend on the dominance of classical or dysregulation mechanisms in this particular situation. Conclusion. The dysregulation mechanism of the effect of water of negative redox potential on renal function is due to the initial mobilization of defense reactions with improved contractile function of the heart, which is subsequently transformed into an injury response due to increased basal renal vascular tone with the development of transient ischemia and renal dysfunction, decrease оf glomerular filtration, filtration fraction of sodium ions, its absolute and proximal reabsorption and development of proteinuria.

Influence of negative redox potential on functional and biochemical processes of the kidneys at the polyuric stage of sublimate nephropathy

Goal. To find out the effect of water load of negative redox potential on the functional and biochemical processes of the kidneys in comparison with induced diuresis with ordinary tap water at the poliuric stage of sublimate nephropathy in hyponatric diets.Materials and methods. In experiments on 60 white non-linear mature male rats in a hyposodium diet at the poliuric stage of sublimate nephropathy 72 hours after subcutaneous administration of sublimate at a dose of 5mg/kg per load of water with a negative redox potential (-232.0±25.12 mV) compared to induced diuresis with ordinary tap water (redox potential 88.7±18.35 mV), which ORP-meter was measured, lipid peroxidation, tissue fibrinolysis, succinate dehydrogenase activity, β-2-microglobulin reabsorption, excretory, ionoregulatory functions were studied, glomerular-tubular and tubular-tubular balance of the kidneys.Results and discussion. According to the experience installed protective, antioxidant effects of water negative redox potential, which was manifested by the decrease in the level of diene conjugates, malonic aldehyde, the degree of swelling and damage by the ratio of K+/Na+ to the cortical substance of the kidney, improve the reabsorption of sodium ions, β-2-microglobulin in the proximal tubules with a reduction in the loss of this cation from urine by increasing the supply of electrons to the tubules of the kidneys. Improving the energy status of the proximal nephron in conditions experience increased activity of succinate dehydrogenase in the cortical portion of the kidney has led to the improvement of tissue fibrinolysis and processes glomerular-tubular and tubular-tubular balance with loss correlations, the relative water reabsorption from the glomerular filtration, absolute proximal and distal reabsorbtion of sodium ions.

The effect of water loading for acute weight loss following fluid restriction on sleep quality and quantity in combat sports athletes

Introduction: Combat sport athletes commonly engage in established and novel acute weight-loss strategies to achieve weight division targets. The effect of such practices on sleep is unknown. Methods: Twenty-two combat sports athletes wore wrist actigraphy devices for nine nights during a training camp and completed questionnaires assessing daytime sleepiness, insomnia, sleep apnoea and chronotype. Athletes were assigned to a control (CG) or water loading group (WLG). Both followed a low residue diet for 96h, and restricted fluid for 24h before weigh-in. Prior to restriction, the CG consumed 40ml/kg and WLG consumed 100ml/kg fluid daily. Results: Four athletes responded positively for the potential prevalence of sleep apnoea (2 CG/WLG), reporting subthreshold insomnia 8±4, athletes were assessed as having an “intermediate chronotype”. Sleep latency estimates in CG were longer on days 4/6 relative to 3 (p<0.05). There was a between-group difference for sleep latency on day 6, with CG taking 35 mins longer (95% CI 5-64mins, p=0.022) to fall asleep. Conclusion: Acute weight loss by means of a low residue diet, both with and without water loading before the fluid restriction is a safe and effective means of manipulating body mass to in the context of sleep.

Effects of Water Loading on Observed and Predicted Plasma Sodium, and Fluid and Urine Cation Excretion in Healthy Individuals

The discovery of sodium storage without concurrent water retention suggests the presence of an additional compartment for sodium distribution in the body. The osmoregulatory role of this compartment under hypotonic conditions is not known. Experimental interventional study. Single-center study of 12 apparently healthy men. To investigate whether sodium can be released from its nonosmotic stores after a hypotonic fluid load, a water-loading test (20mL water/kg in 20 minutes) was performed. During a 240-minute follow-up, we compared the observed plasma sodium concentration ([Na+]) and fluid and urine cation excretion with values predicted by the Barsoum-Levine and Nguyen-Kurtz formulas. These formulas are used for guidance of fluid therapy during dysnatremia, but do not account for nonosmotic sodium stores. 30 minutes after water loading, mean plasma [Na+] decreased 3.2±1.6 (SD) mmol/L, after which plasma [Na+] increased gradually. 120 minutes after water loading, plasma [Na+] was significantly underestimated by the Barsoum-Levine (-1.3±1.4mmol/L; P=0.05) and Nguyen-Kurtz (-1.5±1.5mmol/L; P=0.03) formulas. In addition, the Barsoum-Levine and Nguyen-Kurtz formulas overestimated urine volume, while cation excretion was significantly underestimated, with a cation gap of 57±62 (P=0.009) and 63±63mmol (P=0.005), respectively. After 240 minutes, this gap was 28±59 (P=0.2) and 34±60mmol (P=0.08), respectively. The compartment from which the mobilized sodium originated was not identified, and heterogeneity in responses to water loading was observed across participants. These data suggest that healthy individuals are able to mobilize osmotically inactivated sodium after an acute hypotonic fluid load. Further research is needed to expand knowledge about the compartment of osmotically inactivated sodium and its role in osmoregulation and therapy for dysnatremias. This investigator-initiated study was partly supported by a grant from Unilever Research and Development Vlaardingen, The Netherlands B.V. (MA-2014-01914).

Axisymmetric vibrations of a circular Chladni plate in air and fully submerged in water

In this study, experimental and numerical analyses were performed to determine the effects of water loading on the axisymmetric modes of vibration of a circular plate. The plate was harmonically excited at its centre through an extension bar and its outer edge was left free. The Chladni technique, which involves exciting the plate at a resonance and waiting for sand grains sprinkled on the plate to collect along the nodal circles, was used to identify and visualize the modes both in air and fully submerged in water. Surprisingly, inverse Chladni patterns were observed in water as particles were drawn towards the zero transversal velocity radii by the induced flow. A coupled acoustic–structural finite element model was built to simulate the same modes, which had been preliminarily validated against theoretical results of a completely free edged plate. A good agreement between experimental and numerical natural frequencies and mode shapes was found. The frequency reduction ratio due to the added mass effect was around 64 %. Moreover, measurable differences due to fluid–structure coupling were observed in the radii of the nodal circles between corresponding dry and wet modes.

The impact of water loading on postglacial decay times in Hudson Bay

Ongoing glacial isostatic adjustment (GIA) due to surface loading (ice and water) variations during the last glacial cycle has been contributing to sea-level changes globally throughout the Holocene, especially in regions like Canada that were heavily glaciated during the Last Glacial Maximum (LGM). The spatial and temporal distribution of GIA, as manifested in relative sea-level (RSL) change, are sensitive to the ice history and the rheological structure of the solid Earth, both of which are uncertain. It has been shown that RSL curves near the center of previously glaciated regions with no ongoing surface loading follow an exponential-like form, with the postglacial decay times associated with that form having a weak sensitivity to the details of the ice loading history. Postglacial decay time estimates thus provide a powerful datum for constraining the Earth's viscous structure and improving GIA predictions. We explore spatial patterns of postglacial decay time predictions in Hudson Bay by decomposing numerically modeled RSL changes into contributions from water and ice loading effects, and computing their relative impact on the decay times. We demonstrate that ice loading can contribute a strong geographic trend on the decay time estimates if the time window used to compute decay times includes periods that are temporally close to (i.e. contemporaneous with, or soon after) periods of active loading. This variability can be avoided by choosing a suitable starting point for the decay time window. However, more surprisingly, we show that across any adopted time window, water loading effects associated with inundation into, and postglacial flux out of, Hudson Bay and James Bay will impart significant geographic variability onto decay time estimates. We emphasize this issue by considering both maps of predicted decay times across the region and site-specific estimates, and we conclude that variability in observed decay times (whether based on existing or future data sets) may reflect this water loading signal.

The Effect of Water Loading on Acute Weight Loss Following Fluid Restriction in Combat Sports Athletes.

Novel methods of acute weight loss practiced by combat sport athletes include "water loading," the consumption of large fluid volumes for several days prior to restriction. We examined claims that this technique increases total body water losses, while also assessing the risk of hyponatremia. Male athletes were separated into control (n = 10) and water loading (n = 11) groups and fed a standardized energy-matched diet for 6 days. Days 1-3 fluid intake was 40 and 100ml/kg for control and water loading groups, respectively, with both groups consuming 15ml/kg on Day 4 and following the same rehydration protocol on Days 5 and 6. We tracked body mass (BM), urine sodium, urine specific gravity and volume, training-related sweat losses and blood concentrations of renal hormones, and urea and electrolytes throughout. Physical performance was assessed preintervention and postintervention. Following fluid restriction, there were substantial differences between groups in the ratio of fluid input/output (39%, p < .01, effect size = 1.2) and BM loss (0.6% BM, p = .02, effect size = 0.82). Changes in urine specific gravity, urea and electrolytes, and renal hormones occurred over time (p < .05), with an interaction of time and intervention on blood sodium, potassium, chloride, urea, creatinine, urine specific gravity, and vasopressin (p < .05). Measurements of urea and electrolyte remained within reference ranges, and no differences in physical performance were detected over time or between groups. Water loading appears to be a safe and effective method of acute BM loss under the conditions of this study. Vasopressin-regulated changes in aquaporin channels may potentially partially explain the mechanism of increased body water loss with water loading.

Facilitating donor compliance with strategies to prevent vasovagal reactions: comparison of web‐based and in‐center approaches

Research has documented beneficial effects of water loading (WL) and applied muscle tension (AMT) on reducing self-reported vasovagal reactions (VVRs) in whole blood (WB) donors. However, the optimal approach to reducing VVRs using these strategies in routine blood collection practice is not known. This study evaluated the effectiveness of embedding newly developed web-based and on-site donor education materials to increase the use of these two prevention techniques during blood collection. Two studies were conducted with WB donors. In Study 1, donors (n = 375) were randomly allocated to evaluate one of three forms of educational materials (video, webpage, card) in an online questionnaire. In Study 2, donors (n = 598) were randomly assigned to view either off-site web-based or in-center educational materials and were surveyed after donation to assess compliance to the VVR prevention procedure and to self-report VVR. In Study 1, donors rated the video as having the highest message appeal and indicated greater likelihood to use AMT compared to the webpage and card. No differences were found in likelihood to use WL. In contrast, in Study 2, greater adherence to VVR prevention strategies was observed in donors who received the in-center instruction card in comparison to those who received the web-based materials. Examination of viewing data indicated that only a small number of donors had seen the web-based materials. No significant effects of the techniques were found on self-reported VVRs. Providing on-site instructions is the most effective method to increase donor compliance to VVR prevention techniques.

Renal Response to a Protein Load in Healthy Young Adults as Determined by Iohexol Infusion Clearance, Cimetidine-Inhibited Creatinine Clearance, and Cystatin C Estimated Glomerular Filtration Rate

Renal reserve (RR) measures the increase in glomerular filtration rate (GFR) in response to a protein load; lack of RR could indicate subclinical kidney disease but such a test is not routinely used in clinical practice. The purpose of this study was to compare a meat versus liquid protein load in a cystatin C-based (Cys-C) RR test using cimetidine-inhibited creatinine clearance (Cr Cl) and iohexol infusion clearance (Io Cl) for validation. The design was cross-sectional analysis and the setting was a Clinical Research Center. Participants (N=16), mean (standard deviation [SD]) age 22 (2) years, had normal health and blood pressure without proteinuria. Participants 1 to 8 received a beef burger (1g/kg protein) and participants 9 to 16 received a ProCel shake (1-1.5g/kg protein). RR defined as the difference in stimulated versus baseline GFR. Baseline GFR (SD) in mL/minute/1.73m2 averaged 103.0 (15.6) for Cr Cl, 94.8 (7.9) for Io Cl, and 117.0 (6.0) for Cys-C estimated GFR (eGFR). Mean RR (SD) for the burger group (N=8, mL/minute/1.73m2) was 16.6 (12.3) for Cr Cl (P=.006); 7.2 (3.7) for Io Cl (P<.001), and 4.9 (2.6) for Cys-C eGFR (P=.001). Mean RR for the shake group (N=8) was 15.8 (5.8) for Cr Cl (P<.001), 10.1 (7.8) for Io Cl (P=.008), and 2.4 (2.9) for Cys-C eGFR (P=.05). Protein loading stimulates Io Cl and Cr Cl after a beef or milk-based protein load. The change in Cys-C eGFR is significant but smaller for the shake and burger group, which may be due to the dilutional effect of water loading or the length of Cys-C half-life in the blood.

Hydrothermal liquefaction of sewage sludge under isothermal and fast conditions

We investigated the effects of water loading, sludge moisture content, recovery solvent, and additives on the product yields and compositions from isothermal (673K, 60min) and fast (773K, 1min) hydrothermal liquefaction (HTL) of sewage sludge. The water loading (which affects pressure within the reactor) plays a small role in product yields. The sludge moisture content had a larger effect with the highest biocrude yields (26.8wt% from isothermal HTL and 27.5wt% from fast HTL) being produced from sludge that was 85wt% moisture. The HTL biocrude from sludge mainly contains long-chain aliphatic hydrocarbon moieties and aliphatic acids. Dichloromethane recovered more biocrude and energy content (∼50%) than did the other solvents tested. Added K2CO3, Na2CO3, HCOOH, CH3COOH, MoO3-CoO/γ-Al2O3 and Ru/C significantly decrease the biocrude yield when their loadings are 50wt% of the dried sludge. The additives, excepting carbonates, enhance gasification of sludge.

Water diffusion in zeolite membranes: Molecular dynamics studies on effects of water loading and thermostat

Molecular dynamics simulations were employed to investigate diffusion and structural properties of water molecules confined in one-dimensional zeolites. Several water loadings and thermostatting methods were used, and insight into the effects of these was obtained by comparing diffusion and structural properties. Water diffusion was characterised via mean square displacements (self and collective diffusivities) and radial distribution functions enabled the structural ordering of water for different pore sizes and loadings to be compared. Interestingly at lower loadings, molecules tend to form clusters and move collectively, while at higher loadings, the self-diffusion coefficient in the pores is similar to that in bulk water. The length of the simulation cell was varied to determine the system size effects on the results, and narrow pores were also investigated in order to examine how this affected the effectiveness of water transport through the zeolite.

Effects of Superstrate on Electromagnetically and Gap Coupled Patch Antennas

In this paper the effects of water loading (termed as superstrate) on the characteristics of an electromagnetically (EM) and coupled pentagonal patch antennas operating in the ISM band have been described. The proposed antenna structures are analyzed using HFSS and the influence of the superstrate on resonant frequency, bandwidth, VSWR and radiation characteristics have also been analyzed. The obtained results also reveal that a larger bandwidth can be found in case the dielectric substrate is separated by air gap spacing. In addition, though impedance matching is little deteriorated due to loading, however the operating frequency band (BW) shifted to lower side significantly.

Abstract 330: Blood Oxygen Level Dependent (BOLD) MR evaluation of renal oxygenation is unaffected by water loading in atherosclerotic renovascular disease

Background: Renal hypoxia is a complex function of post-glomerular medullary blood flow, active solute transport and is considered a major risk element for acute kidney injury. Previous studies indicate that sodium balance, diuretic administration and some drugs affect tissue oxygenation. Water loading in younger subjects lowers medullary deoxyhemoglobin. We sought to evaluate the effects of water loading on the day of BOLD imaging in older subjects undergoing protocol evaluation of atherosclerotic renovascular disease (ARVD). METHODS: Inpatient studies were performed in patients with hemodynamically severe ARVD (n=15, Doppler US velocity &gt;270 cm/sec), during 150 mEq Na+ intake and ACE/ARB Rx. Two groups were studied: Group A (n=10) received oral water loading (20 ml/kg), whereas Group B (n=5) had none. Tissue R2* (index of deoxyhemoglobin levels) and fractional kidney hypoxia (medullary estimate) (% of renal coronal area with R2*&gt;20/s) were measured in stenotic kidneys by BOLD-MRI at 3T, before and after IV injection of Furosemide (20gm). RESULTS: Cortical R2* and fractional tissue hypoxia were similar for the 2 groups (P =0.6 and 0.7). Both groups reduced cortical R2* and fractional hypoxia after furosemide injection to the same degree. Table CONCLUSION: These data demonstrate that water loading on the day of BOLD evaluation in older subjects with ARVD does not materially alter cortical or medullary estimates of oxygenation. Our results extend previous studies indicating that water loading in older individuals fails to alter medullary oxygenation unlike alterations in sodium intake, diuretic administration or blockade of the renin-angiotensin system.

Statistical analysis of vibration and sound radiation of submerged stiffened rectangular plates

In order to extend the statistical energy analysis (SEA) method to predict the vibration and sound radiation of underwater structures, we mainly analyze the effect of water loading on the key parameters in SEA and propose the approximate expressions of modal density and mean square velocity of submerged plates. With the radiation efficiency of submerged plates previously proposed by us, the modified SEA solutions of the radiated sound power and mean square velocity of submerged stiffened rectangular plates are established. Numerical examples show that the modified SEA solutions are more close to the theoretical solutions than the present SEA solutions, and reflect the mean value or trend of the theoretical solution much better, especially at lower frequencies. An experiment of point-exciting submerged plates was done in a lake. The experiment values show that for both un-stiffened and stiffened plates, the modified SEA solutions have a good agreement while the present SEA solution has considerable error, which validates the established statistical model.