Continuous Wetting Research Articles

Successful Management of Renal Fusion Anomaly of Kidney with Nephrolithiasis and Urinary Incontinence

The presence of an ectopic ureter may be indicated by continuous wetting, seen especially in girls. In majority of such cases, an ectopic ureter is associated with a duplex collecting system and complete ureteral duplication. A 32-year-old female presented with urinary incontinence with normal voiding episodes and right flank pain. On investigation, she was found to have duplex moiety on the right-side with partially duplicated ureter and quadruple moiety on the left-side with partially duplicated quadruple ureter with ectopic opening of ureters. The patient also had right upper calyceal stone. It was successfully managed with totally minimal invasive technique with retrograde intrarenal surgery for right nephrolithiasis and left laparoscopic ureteric reimplantation for ectopic ureter. Patient was continent during the follow-up period of nine months with no significant complications. Developmental anomalies of kidney and ureter though rare, can be managed with total minimal invasive techniques, requires proper planning, instruments and its implementation.

Nonwet Kingfisher Flying in the Rain: The Tumble of Droplets on Moving Oriented Anisotropic Superhydrophobic Substrates.

Extensive studies of antiwetting have been restricted to stationary substrates, while dewetting mechanisms on moving interfaces are still poorly understood. Due to the hydrophobic and anisotropic surface characteristics of kingfishers, they are able to easily change flight direction even under high-intensity precipitation. The present study aims to mechanistically analyze how the synergy of interfacial movement, anisotropy, and superhydrophobicity affects rapid dehydration. We have designed a droplet-conveyor system to simulate the bouncing of droplets on moving anisotropic superhydrophobic targets and performed simulations via the lattice Boltzmann algorithm. The moving interface can induce a directional tumbling behavior of the droplet and effectively avoid continuous wetting in the same region. We found that droplet tumbling is essentially caused by transformed depinning velocity vectors at the interface downstream. Also, the hang time of a tumbling droplet is positively related to the angle between the motion vector and the texture. The oriented anisotropic motion facilitates the tumbling of droplets and decreases their hang time by up to 23% as compared to that on a stationary inclined superhydrophobic surface. Similar interfacial process dehydration also occurs on a nonwet kingfisher flying in the rain, and we believe that these findings provide valuable new insights for high-efficiency water repellency of surfaces.

A 3D inlet distributor employing copper foam for liquid replenishment and heat transfer enhancement in microchannel heat sinks

The application of two-phase flow boiling to microchannel heat sinks has attracted increasing attention owing to the compact design and high efficiency of dissipating heat. However, undesirable heat transfer deterioration and premature critical heat flux are commonly encountered in real-life applications of two-phase flow cooling devices. One significant challenge in utilizing two-phase flow boiling in microchannels lies in preventing the thin liquid film and in-time liquid replenishment from being interrupted by the rapid bubble elongation and chaotic vapor-liquid interface in the channel. In the present work, a 3D inlet distributor employing copper foam is proposed as an extra liquid feeding path to facilitate continuous liquid wetting of the boiling surface and improve the heat transfer performance. A physical heat transfer model accounting for the differences in microchannel void fraction and liquid film thickness caused by the copper foam layer (CFL) has been proposed to describe the working mechanism. The validity of the proposed 3D inlet distributor in heat transfer enhancement was verified using a series of flow boiling tests, employing deionized water as the working fluid. It was found that the local overheating of the microchannel heat sink was demonstrably reduced for all the heat flux values (q) in the tests after adopting the CFL, with a maximum reduction of 14 K at q = 397.6 kW/m2, where local dry-out was successfully inhibited. The heat transfer coefficient of the microchannel heat sink with the CFL was improved by approximately 1.7 times compared to the case without the CFL and could be maintained at 41 kW/m2K during elongated bubble flow and annular flow patterns. In addition, the proposed distributor was capable to resist gravity and long-term severe boiling, thus achieving superior and reliable performance under various orientations as well as during long operating hours.

Kidney triplication with ectopic ureterocele: a case report

BackgroundKidney triplication is a rare urological abnormality. Association of triplex kidney and ureterocele is out of ordinary. Treatment of such patients usually implies heminephrureterectomy of the upper moiety. We report a case of a saved function of the upper moiety after minimal invasive surgical procedure.Case presentations5-year old girl complained for continuous wetting. Examination revealed 3 - segmented left kidney with pelvi-ureteric dilation of the upper moiety, IV grade vesicoureteral reflux in the upper moiety, cervical ectopic ureteral orifice of the upper moiety and a commune ureteral orifice of the lower segments.An endoscopic laser dissection of ureterocele was performed. Drainage of the upper moiety of triplex kidney was restored. Examination 18 months later showed no wetting and infection symptoms. Pelvi-ureteric dilation of the upper moiety and cavity of ureterocele decreased to minimal. Grade of vesicoureteral reflux decreased to I.ConclusionMinimal invasive elimination of obstruction of the upper moiety of triplex kidney was successful and led to regress of vesicoureteral reflux, urinary incontinence and let to avoid heminephrectomy.

Transpiration reduction and absorption of intercepted water in Leyland cypress (× Cupressocyparis leylandii) and European common oak (Quercus robur)

Precipitation that is intercepted by vegetation is generally considered as lost to the terrestrial hydrological cycle. However, if it is absorbed by the plants or reduces their transpiration, the intercepted water contributes positively to forest hydrology. The aim of this study was to investigate the absorption of intercepted water by a conifer and an angiosperm tree species. Pots of 2–3-year-old plants of × Cupressocyparis leylandii and Quercus robur were wrapped in plastic bags to exclude stemflow and throughfall from their water supply. Samples of both species were conditioned to two levels of aboveground wetting (sprinkled or un-sprinkled) and two levels of soil moisture (dry or moist). The periodical sprinkling with water droplets, lasting 5 h during two nights and 10 h in 1 day, ensured continuous aboveground wetting of plants during these periods. Weight changes of the plants were monitored after air drying in darkness for 3 h and wiping off any remaining surface water. Absorption of intercepted water was apparent for both species at night, when transpiration was close to zero. During the day, sprinkled plants of Q. robur had reduced rates of transpiration. For C. leylandii on dry soil sprinkling reduced water consumption during the first 24 h by 9%, while for Q. robur, the reductions were 46% and 27% for plants on dry and moist soils, respectively. These reductions in water consumption following sprinkling indicate that transpiration reduction and absorption of intercepted water deserve attention in studies of forest hydrology.

Effect of drying treatment on the leachability of metallic elements from weathered solid mine wastes

Leaching of toxic metallic elements (Cu, Zn, As, Cd, and Pb) from two solid mine wastes was characterized under different drying treatments. During 14 batch decant-refill leaching steps, samples were intermittently dried four times in 40 °C oven or −20 °C freezer. For all leachates, the pH, pE, Fe2+/Fe3+, and SO42− were analyzed. The parameters of the two-site model (kfast, kslow, and ffast) and labile fractions (F1 + F2) were determined. High levels of toxic metallic elements were determined in waste samples; however, their leaching was limited, as evidenced by the magnitudes of F1 + F2, ffast, and kslow. Leachate solutions were acidic, at pH 3–4, and oxic, at 150 mV < Eh 300 < mV, thus having negligible Fe2+. Leachate concentrations of toxic metallic elements increased (4–58%) after drying at 40 °C and were strongly correlated (r2 = 0.780) with those of sulfate in liquid phase. The mass of element elution was in the order of 40 °C drying > −20 °C drying ≥ continuous wetting. Results indicate that the element leachability is increased through drying events and the leachate concentration is associated with the dissolution reaction of sulfur-bearing minerals. Frequent occurrence of prolonged droughts along with high temperatures over the mine waste disposal site, can enhance the leaching potential of toxic metallic elements.

Experimental investigation and simulation of nitrogen transport in a subsurface infiltration system under saturated and unsaturated conditions

The nitrogen dynamics in a subsurface infiltration system (SIS) are affected by many factors, including temperature, system design, and feed water quality, which are not easily quantified. In this study, a column experiment was conducted to simulate an SIS. The HYDRUS-1D software package was used to investigate and quantify the factors that affect nitrate transport in an SIS. Three treatments were carried out based on different hydraulic conditions, including continuous wetting (CW), wetting/drying (WD), and a specific hydraulic loading rate (SH). The effects of hydraulic conditions and temperature on nitrate transformation were investigated. The model was calibrated and validated using two-year experimental data. Simulations of cumulative outflow volume and nitrate concentration fitted well with the observations. Among the three SISs, the denitrification rate was greatest under unsaturated conditions at high water temperature. The denitrification rate constant had an exponential relationship with temperature. An empirical formula describing this relationship was developed and validated in the SIS. The results showed that the SH column attained the greatest nitrate removal efficiency, mainly due to its low hydraulic loading and long retention time. Overall, the results showed that HYDRUS-1D adequately simulated nitrate transport through the soil column under different temperature and hydraulic conditions in an SIS. The fate of nitrate was directly controlled by the water temperature and hydraulic conditions.

The Impact of Mechanical Weathering on the Durability Strength Index of Ayer Hitam Shale Under Various Weathering Grades and Conditions

Shale is significantly weaker and less durable than other types of rock and is easy to break when it is exposed to continuous wetting and drying activities. As a construction material, the durability strength index of weathered shale in Ayer Hitam, Johor, Malaysia is poorly investigated and not well understood. The purpose of this study is to investigate the effect of mechanical weathering on the durability strength index of Ayer Hitam weathered shale under several different conditions. Three hundred sixty samples of weathered shale which are classified as weathering grade II to IV were tested within the fifth cycles of the slake durability test under three different conditions namely: Natural weathering, dry, and saturated sample. The results showed that the weathered shale with the highest moisture content of 27.78% and the lowest strength index with 1% after the fifth cycle at week 8 was the weathering grade IV under saturated condition. It was also found that the reduction in the durability strength index was more than 90% with increased moisture content and weathering grades. In conclusion, the durability strength index of shale depends upon the number of cycles or weathering grade, duration of water immersion as well as moisture content.

Compressive Strength of Concrete Using Different Curing Methods

The structural use of concrete depends largely on its strength, especially compressive strength.Various tests were carried out to ascertain the properties of concrete materials, whereas test performances ofthe concrete with different mix ratios at specific ages of curing were undertaken. The study determined thecompressive strength of concrete using different curing methods. Four different methods of curing (ponding,continuous wetting, open-air curing and sprinkling with water) were used. Seventy-two (72) cubes were castusing a mix ratio of 1:2:4 and 1:3:6 with 0.5 water cement ratio and with 0.6 waters cement ratio respectively.The compressive strengths were determined after 7 days, 14 days and at 28 days of curing. Findings showthat for 1:2:4 concrete, maximum of 28-day compressive was the highest for concrete cured by ponding andthe least was by sprinkling water. Further findings show that for 1:3:6 concrete, maximum of 28-daycompressive strength was obtained using ponding and the least was open air curing. Despite ponding methodproducing the highest compressive strength of concrete, it is practically impossible to cure cubes aboveground structural elements. Wet-covering method is recommended for structural elements, such as columns,beams and slabs in other to produce concreteof a required compressive strength.

Engineering rhizobacterial community resilience with mannose nanofibril hydrogels towards maintaining grain production under drying climate stress

Ongoing impacts of climatic change especially moisture stress remain a global challenge to agricultural production and food security. Such abiotic effects directly influence soil microbial communities. Previously we demonstrated that polymeric hydrogels, able to provide specific interactions with soil microbial communities, enhance the dynamics and selectivity of ingress and colonisation of plant beneficial bacteria at soil microcosm scales. We now show that small quantities of osmotic hydrogels containing mannose nanofibrils specifically situated in close proximity to developing root zones provide enhanced microbial ingress, colonisation and continuous wetting pathways when contacting developing wheat root systems. These effectively create extensions to the natural rhizosphere sustaining significant beneficial rhizobacterial communities when under moisture stress. Sequencing studies, on wheat production soils undergoing a season of low average rainfall clearly showed microbial abundance increases and taxa selectivity in the rhizosphere-hydrogel regions compared to controls. Here wheat yields increased by about 20% with hydrogel addition compared to controls, which represented a 15% increase in the overall average yield in the region. This represents the first reported demonstration that developing rhizospheres may be readily engineered to consistently select their own distinct microbiome as nodes of functional microbial abundance significantly benefiting grain yield during abiotic stress. Thereby suggesting new opportunities to maintain grain yields during periods of drying climate via these fibrillar hydrogels.

Continuous Wetting on the Tibetan Plateau during 1970–2017

Based on daily observation records at 277 meteorological stations on the Tibetan Plateau (TP) and its surrounding areas during 1970–2017, drought evolution was investigated using the Standardized Precipitation Evapotranspiration Index (SPEI). First, the spatiotemporal changes in the growing season of SPEI (SPEIgs) were re-examined using the Mann–Kendall and Sen’s slope approach—the piecewise linear regression and intensity analysis approach. Then, the persistence of the SPEIgs trend was predicted by the Hurst exponent. The results showed that the SPEIgs on the TP exhibited a significant increasing trend at the rate of 0.10 decade−1 (p &lt; 0.05) and that there is no significant trend shift in SPEIgs (p = 0.37), indicating that the TP tended to undergo continuous wetting during 1970–2017. In contrast, the areas surrounding the TP underwent a significant trend shift from an increase to a decrease in SPEIgs around 1984 (p &lt; 0.05), resulting in a weak decreasing trend overall. Spatially, most of the stations on the TP were characterized by an increasing trend in SPEIgs, except those on the Eastern fringe of TP. The rate of drought/wet changes was relatively fast during the 1970s and 1980s, and gradually slowed afterward on the TP. Finally, the consistent increasing trend and decreasing trend of SPEIgs on the TP and the area East of the TP were predicted to continue in the future, respectively. Our results highlight that the TP experienced a significant continuous wetting trend in the growing season during 1970–2017, and this trend is likely to continue.

Order-disorder transition of an argon adsorbate in graphitic wedge pores

From her exhaustive X-ray studies of graphitized and non-graphitized carbons, Rosalind Franklin (1951), Franklin (1950, 1951,1953) and Harris (2001) deduced that pores in these materials exist as wedge shaped spaces in the interstices between graphitic micro-crystallites. In this paper we investigate the order-disorder transition of adsorbed argon in carbonaceous materials, modelled as a closed wedge formed by two sets of graphene layers. Despite its simplicity, the model captures the physics of adsorption in a non-uniform pore and gives rise to a rich adsorption behaviour. Our particular focus in this work is on the wetting/filling of argon and its variation with the wedge angle and temperature. We find that incomplete wetting occurs at temperatures below the roughening temperature, TR = 70 K, and that continuous wetting occurs above this temperature. We summarise our results as a phase diagram for wetting/filling of argon adsorption in graphitic wedges as a function of wedge angle and temperature.

Influence of cyclic wetting‐drying on the mechanical strength characteristics of coal samples: A laboratory‐scale study

AbstractWater‐coal interactions have gained much recent attention, although few studies focus on the strength of coal under wetting‐drying cycles. This study investigates changes in the microstructure and mechanical strength of coal that are induced by water‐coal interactions, at the macroscale and microscale. Fourteen specimens after continuous wetting and fourteen specimens after wetting‐drying cycles were tested, indicating that peak stress and elastic modulus decrease with increasing continuous wetting time and number of wetting‐drying cycles, while peak strain increases. We analyzed changes in the coal microstructure using a scanning electron microscope (SEM) and the Image Pro Plus 6.0 (IPP 6.0) software. The regression model for cyclic wetting‐drying reveals that porosity and pore circularity are the main correlation indicators associated with uniaxial compressive strength. Therefore, different numbers of wetting‐drying cycles could induce different degrees of damage to coal, which increases progressively through gradual changes to its microstructure. These findings indicate that wetting‐drying cycles have a more significant impact on the stability of coal mass than continuous wetting. Our results are of use in determining the size of coal pillars, and expanding the knowledge base related to the mechanical properties of coal mass, water bursting, water recharge channels, and the stress‐crack‐permeability evolution law in mines.

Effective attenuation length dependence on photoelectron kinetic energy for gold from 1 keV to 10 keV: Role of island growth in overlayer experiments

We analyzed the experiments of Rubio-Zuazo and Castro [J. Electron Spectrosc. Relat. Phenom. 184 (2011) 384] who reported measurements of effective attenuation lengths (EALs) of gold for electron energies between 1 keV and 15 keV. They deposited thin films of gold on a copper substrate and measured the intensities of various Cu and Au photoelectron lines excited by synchrotron X-rays. Their derived EALs were based on the assumption that their films were of uniform thickness (i.e., layer-by-layer film growth). We considered two other forms of film growth: island formation (Volmer-Weber film growth) and island growth on a continuous monatomic wetting layer (Stranski-Krastanov film growth). We utilized the National Institute of Standards and Technology Database for the Simulation of Electron Spectra for Surface Analysis (SESSA) to determine the fractional Au island areas for each Au film thickness that would give the same intensity changes of Cu and Au photoelectron lines that were observed in the experiments. These results showed that growth of the Au film as islands provided a better description of the experimental results than uniform film growth. We could also distinguish Stranski-Krastanov film growth from Volmer-Weber growth and believe that the former is more likely.

On the Nonwetting/Wetting Behavior of Carbon Dioxide on Graphite

Extensive simulations of CO adsorption on graphite were carried out over a range of temperature to investigate the effects of temperature on the nonwetting/wetting transition. CO adsorbed on graphite is nonwetting below the bulk triple-point temperature (T = 215 K) but wetting above this temperature and differs from noble gases, which form an adsorbed film at all temperatures. Our simulation results confirm that the CO /graphite system is nonwetting at temperatures below 90 K, as reported experimentally by Terlain, A.; et al. [Phase Diagrams of Films of Linear Molecules with Large Quadrupole Moments (CO , N O, C N ) Adsorbed on Graphite. Surf. Sci. 1983, 125, 304-311] and by Morishige, K. [The Structure of a Monolayer Film of Carbon Dioxide Adsorbed on Graphite. Mol. Phys. 1993, 78, 1203-1209]. For temperatures between the wetting temperature of 90 K and the bulk triple point, incomplete wetting occurs, and the adsorbed film has a finite thickness at the bulk coexistence pressure. This is a consequence of the fact that the isosteric heat of adsorption at zero loading, (0), is lower than the heat of sublimation of bulk CO . On the other hand, at temperatures greater than T , the adsorption isotherm exhibits continuous wetting as the pressure approaches the bulk coexistence pressure because qs(0) is greater than the bulk heat of condensation. We support these findings with detailed analysis of the molecular configurations along the canonical isotherms, the isosteric heat as a function of loading, and the local orientation-density distributions. The two-dimensional critical temperature of the first adsorbate layer was determined as 130 K, in excellent agreement with 127.5 K estimated experimentally by Terlain, A.; et al. [Phase Diagrams of Films of Linear Molecules with Large Quadrupole Moments (CO , N O, C N ) Adsorbed on Graphite. Surf. Sci. 1983, 125, 304-311]. In the final section, we present a parametric map showing regions of nonwetting, wetting, and incomplete wetting for CO adsorption on the surface of adsorbents of different strengths.

Maintenance of cell viability in extraoral conditions for a case of intentional replantation to retrieve a separated endodontic instrument

Intentional replantation has been used as an alternative treatment modality to tooth extraction and prosthetic replacement when conventional endodontic treatment modalities are unfeasible or contraindicated. This case report presents a successful case of intentional replantation for the mandibular first molar with an endodontic mishap. An endodontic instrument was separated in the apical third of the root canal and extended beyond its mesiobuccal root apex. Intentional replantation served as a means to remove the separated instrument. The periodontal ligament (PDL) cells were kept viable throughout the endodontic treatment using a distinctive technique, wherein a preoperative impression is used for continuous wetting with saline. Platelet-rich fibrin (PRF) was shredded and placed in the alveolar socket to enhance PDL cell reattachment and prevent ankylosis. The 2-year successful follow-up reinforced that intentional replantation can be a viable option for removal of separated instruments that lie beyond the root apex. The use of these techniques to keep PDL cells viable and the use of PRF can aid in prevention of ankylosis.

Performance of rice under different water regimes and plant nutrient sources

Field experiment was carried out at the Soil and Irrigation Research Centre, University of Ghana, Kpong in 2015 and 2016 cropping seasons to evaluate the effect of different soil water condition and plant nutrient sources on the growth and yield of rice. The experiment was laid out in a split plot design with three replications. Water regime and nutrient source were the main and sub-plot factors, respectively. Water regimes included; continuous flooding (CS), alternate wetting and drying (AWD) and moist soil condition between field capacity and permanent wilting point (MC) while the nutrient fertilizer treatments included no fertilizer (N0), 90 kg N/ha mainly from urea fertilizer (N1), 90 kg N/ha from 12.8 tons of compost (N2) and 45 kg N/ha from urea fertilizer + 45 kg N/ha from 6.4 tons of compost (N3). Results from the study revealed that keeping the soil periodically in aerobic and anaerobic condition through AWD method of water management recorded similar growth and grain yield of rice as with complete submergence of paddy field. Combination of inorganic fertilizer and compost for each to supply 45 kg N/ha under AWD produced the highest rice growth and grain yield. There was a positive and significant correlation between grain yield and growth parameters (plant height, chlorophyll content and above ground biomass accumulation).

Nonwetting/Prewetting/Wetting Transition of Ammonia on Graphite.

Simulations of ammonia adsorption on graphite were carried out over a range of temperatures to investigate the transition from nonwetting to wetting. The process is governed by a subtle interplay between the various interactions in the system and the temperature. At temperatures below the bulk triple point, the system is nonwetting; above the triple point, we observed continuous wetting, preceded by a prewetting region in which the so-called thin-to-thick film transition occurs. This system serves as an excellent example of wetting/nonwetting behavior in an associating fluid as a function of temperature because the heat of sublimation (or condensation) is greater than the isosteric heat of adsorption at zero loading. The nonwetting-to-wetting transition (NW/W) is also strongly affected by the adsorbate-adsorbate interaction, which becomes important when this contribution to the isosteric heat is of a similar magnitude to the heat of condensation. An appropriate indicator of a NW/W transition at a given loading is therefore the difference between the isosteric heat and the heat of sublimation (or condensation). Our simulation results show the "thin-to-thick" film transition in the temperature range between 195 and 240 K, which has not been previously explained. Above 240 K, continuous wetting occurs. This study provides a basis for a better understanding of adsorption in a range of systems because ammonia is an intermediate between simple molecules, such as argon, and strongly associating fluids, such as water.

Effects of temperature on the transition from clustering to layering for argon adsorption on substrates of different strength - Parametric map of wetting, pre-wetting and non-wetting

Abstract We have carried out extensive simulations of argon adsorption on substrates of different strengths to investigate the effects of temperature on the transition from non-wetting to wetting. For moderately weak substrates, pre-wetting in the so-called “thin-to-thick film” transition occurs. We show that at a microscopic level this is a transition from an adsorbate composed of clusters to one of adsorbed layers. At the wetting temperature (Tw), this transition occurs at the saturation vapour pressure, and Tw depends on the relative strength of the intermolecular interaction between adsorbate molecules and between the adsorbate and the adsorbent, and that Tw increases as the adsorbent strength decreases. The appropriate parameter to account for the role of temperature in the wetting transition is the ratio of the isosteric heat to the heat of condensation, which is a measure of the relative strength between adsorption and cluster formation. At temperatures greater than Tw, the adsorption mechanism is layer-by-layer wetting if the wetting temperature is lower than the roughening temperature (TR). On the other hand, if the wetting temperature is greater than TR the mechanism is either continuous wetting or pre-wetting, which then transitions to continuous wetting when the temperature is greater than the critical pre-wetting temperature. Our study shows that the transitions from non-wetting to pre-wetting to wetting, occur not only in the first adsorbate layer, but also in higher layers.

A Rare Case of Double-System With Ectopic Ureteral Openings Into Vagina

The presence of an ectopic ureter may be indicated by continuous wetting, despite a normal voiding pattern, especially in girls. In most cases, an ectopic ureter is associated with a duplex collecting system and complete ureteral duplication. A 5-year-old girl presented with urinary incontinence regardless of the successful toilet training and a suspicion of left duplex kidney on a previous ultrasound. Contrast-enhanced computed tomography revealed a double left kidney with double ureters, both inserting together into the vagina. The surgical treatment consisted in the “en block” reimplantation of the ectopic ureters into the bladder, with complete resolution of the symptoms. The reported case does not represent just a typical presentation of a single ectopic ureter, as the duplex kidney system had ectopic both ipsilateral ureters (with insertion into the vagina). This case reminds us that congenital abnormalities of the genito-urinary tract should be considered in case of urinary incontinence and recurrent urinary tract infections.