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Coal seam pre-drainage technology is widely used to prevent and control gas in China's high-gas coal seams, and upward drilling is a safe and reliable technology. Using the Luling Coal Mine as the study location, according to the actual situation of the site, a layer-through drilling process was proposed. Relying on a cross-layer extraction borehole, coal seam water injection efficiency extraction and high-efficiency water injection dust prevention can be performed in the later stage of borehole extraction, enabling one-hole multi-purpose and "gas-powder" integrated prevention and control. In order to study the "stress-seepage" coupling characteristics of the coal around the borehole, a numerical simulation of the coal seam water injection process was conducted. Based on the simulation results, a field test of water injection in coal seam upward drilling was performed. The field monitoring data show that the water injection and water content of the coal seam were increased by about 3.07 m3 and 0.69%, respectively, compared with the traditional water injection process. The water injection effect is remarkable, which is of great significance to ensure the safe and efficient production of the mine. [ABSTRACT FROM AUTHOR]

Shimen Reservoir Irrigation Area is a large-sized irrigation area in Hanzhong Plains. It is of great significance to study the water use efficiency of typical irrigated areas through water balance test to realize the mode, experience and practice of the strictest water resource management system. By conducting water balance tests of point, line and plane in irrigated area, and the quantitative relationship between water distribution and water delivery, water facilities operation, total water consumption and water consumption in each region is obtained. Based on the test data, this paper calculates the utilization efficiency of irrigation water, analyzes the water use efficiency of the irrigated area by combining the geomorphology, crop distribution, channel lining and other factors, and studies its improvement measurement. The results indicate that in hilly areas, rice planting and water leakage from low level channels are the major factors of water loss in irrigated areas, which provide important basis for water use efficiency and water-saving scheme in irrigated areas. [ABSTRACT FROM AUTHOR]

The possibility of application for lignin, a byproduct of paper and pulp production, as a partial replacement for cement in producing mortars and concretes is presented. Initially, mortars were prepared with substitution rates ranging from 0.0% to 50.0% to determine the best rates for subsequent application in concretes. Statistical analysis showed that the rates with the highest potential for application in concretes were 2.5%, 5.0%, and 10.0%. After preparing the concretes, test specimens were molded and subjected to axial compression, splitting tensile strength, water absorption by immersion, void ratio, and capillary water absorption tests after the curing period. The results showed that lignin, in rates higher than 5.0%, led to decreased mechanical strength; however, all concretes with lignin significantly reduced capillary water absorption, which can lead to greater material durability. [ABSTRACT FROM AUTHOR]

The photothermal properties of a series of neutral radical gold‐bis(dithiolene) complexes absorbing in the near‐infrared‐III window (1550–1870 nm) have been investigated. This class of complexes was found to be good photothermal agents (PTAs) in toluene under 1600 nm laser irradiation with photothermal efficiencies around 40 and 60 % depending on the nature of the dithiolene ligand. To the best of our knowledge, these complexes are the first small molecular photothermal agents to absorb so far into the near infrared. To test their applicability in water, these hydrophobic complexes have been encapsulated into nanoparticles constituted by amphiphilic block‐copolymers. Stable suspensions of polymeric nanoparticles (NPs) encapsulating the gold‐bis(dithiolene) complexes have been prepared which show a diameter around 100 nm. The encapsulation rate was found to be strongly dependent on the nature of the dithiolene ligands. The photothermal properties of the aqueous suspensions containing gold‐bis(dithiolene) complexes were then studied under 1600 nm laser irradiation. These studies demonstrate that water has strong photothermal activity in the NIR‐III region that, cannot be overcome even with the addition of gold complexes displaying good photothermal properties. [ABSTRACT FROM AUTHOR]

As a crucial indicator in food and water safety testing, the detection of Escherichia coli plays a significant role in maintaining environmental sanitation and promoting public health. Herein, based on the electrochemical activity characteristics of E. coli, we established an enhanced electrochemiluminescence aptasensor for E. coli analysis. This study presents a new method for accurate identification by utilizing a double aptamer recognition system. Specifically, a nano-cadmium sulfide (CdS) modified aptamer was used for primary labeling, while a second aptamer was immobilized on a graphene/chitosan composite electrode for re-capture. The use of two aptamers improves the accuracy of the identification process. Furthermore, the application of an electrode potential facilitates continuous electron transfer between the electrode and electrochemically active microorganisms, resulting in an enhanced electroluminescence signal in relation to the metabolic status. This strategy possesses better sensitivity, accuracy, and stability, demonstrating its potential for E. coli analysis. [ABSTRACT FROM AUTHOR]

The purpose of this study is to explore the development depth of rock layer rupture and analyze the developmental regularity of mining floor in Dongsi mining area of Xinzhi Coal Mine. Two kinds of pressure water testing methods and numerical simulation are used to study the failure characteristics of the bottom plate of the working face in Dongsi mining area of Xinxian Coal Mine. The results show that the failure of working face bottom plate starts from a certain range in front of the working face. With the advance of working face, the failure depth of mining bottom plate increases continuously. At the same time, the failure range of mining roadway is slightly larger than the failure range of working face bottom plate due to the double disturbance of tunneling and mining. The pressure water test shows that the rupture depth occurs at 8.98-9.03 m. The numerical simulation results of floor failure depth show that its depth is about 8.7 m, which is basically consistent with the pressure water test. It provides a reference for the advanced preexploration of mining bottom plate failure in similar coal seam. [ABSTRACT FROM AUTHOR]

Hydrogen is one of the most widely used essential chemicals worldwide, and it is also employed in the production of many other chemicals, especially carbon-free energy fuels produced via photoelectrochemical (PEC) water splitting. At present, gallium arsenide represents the most efficient photoanode material for PEC water oxidation, but it is known to either be anodically photocorroded or photopassivated by native metal oxides in the competitive reaction, limiting efficiency and stability. Here, we report chemically etched GaAs that is decorated with thin titanium dioxide (~30 nm-thick, crystalline) surface passivation layer along with nickel-phosphate (Ni-Pi) cocatalyst as a surface hole-sink layer. The integration of Ni-Pi bifunctional co-catalyst results in a highly efficient GaAs electrode with a ~ 100 mV cathodic shift of the onset potential. In this work, the electrode also has enhanced photostability under 110 h testing for PEC water oxidation at a steady current density Jph > 25 mA·cm−2. The Et-GaAs/TiO2/Ni-Pi║Ni-Pi tandem configuration results in the best unassisted bias-free water splitting device with the highest Jph (~7.6 mA·cm−2) and a stable solar-to-hydrogen conversion efficiency of 9.5%. Photocorrosion limits the efficiency and stability of gallium arsenide photoanodes. Here the authors report crystalline TiO2 passivation with Ni-phosphate hole-sink layer which enables rapid charge transport for enhanced photostability of 110 h. [ABSTRACT FROM AUTHOR]

The current research aims to: - Construction of speed-distinguished strength tests for the arms in the free-swimming activity for advanced swimmers in the central and northern regions of Iraq - Setting standards and levels for strength tests characterized by speed for the arms in free swimming designed in the research The research community included advanced swimmers in free swimming in some clubs in the governorates of Baghdad, Sulaymaniyah, Kirkuk, Erbil and Mosul (the central and northern regions) in Iraq As for the research sample, they were chosen in a deliberate way to achieve the objectives of the research. They numbered (96) swimmers. They represented the two construction samples for tests and standards, as the proportion of the research sample was (61.14%) of the total research community - A number of physical-skill tests in the water were reached for advanced swimmers in the central and northern regions of Iraq, which have good scientific foundations of honesty, stability, objectivity and an appropriate natural distribution, and the number is (2) tests, and these tests are - Testing the speed-characterized force of the arms strikes from stability in the water - Testing the speed-characterized force of the blows of the arms from the movement in the water - Scores tables and standard levels of physical and skill tests in free swimming in the water for advanced swimmers have been reached Most of the swimmers in the central and northern regions were at an acceptable, average and good standard in all physical-skill tests designed in the research. [ABSTRACT FROM AUTHOR]

In this study, we investigated mineral water's therapeutic and prophylactic effects from springs 1 and 1 bis in Slanic Moldova, focusing on identifying the molecular mechanisms responsible for these effects. We collected water samples from these springs and analyzed their chemical composition using various analytical techniques. In addition, we tested the effects of water on cell viability using primary fibroblasts in culture and performed MTT assays to assess the metabolic activity of the cells. Our results indicate that water from both springs has beneficial properties on cells, including improving cell viability and stimulating metabolic activity. This suggests that the mineral water from springs 1 and 1 bis could have therapeutic and prophylactic potential due to its unique chemical composition. Our study could contribute to developing new mineral water-based therapies for various health conditions. [ABSTRACT FROM AUTHOR]

At present, the majority of water testing is carried out in the laboratory, and portable field methods for the quantification of elements in natural waters remain to be established. In contrast, portable instruments like portable X-ray fluorescence (pXRF) analysis and portable laser-induced breakdown spectroscopy (pLIBS) have become routine analytical methods for the quantification of elements in solids. This study aims to show that pLIBS can also be used for chemical compositional measurements of natural waters. Bottled mineral waters were selected as sample materials. A surface-enhanced liquid-to-solid conversion technique was used to improve the detection limits and circumvent the physical limitations in liquid analysis. The results show that low to medium mineralised waters can be analysed quantitatively for their ions using the documented method. For more highly concentrated samples, typically above an electrical conductivity (EC) of 1000 µS/cm, further adjustment is required in the form of self-absorption correction. However, water with a conductivity up to this limit can be analysed for the main cations (Li+, Na+, Mg2+, K+, Ca2+, and Sr2+) as well as the main anions (SO42− and Cl−) using the documented method. This study demonstrates that there is significant potential for developing field-based pLIBS as a tool for quantitative water analysis. [ABSTRACT FROM AUTHOR]

The objective of this paper was to study the impact of crushing and grinding on the porosity of hardened cement paste, which is responsible for the high values of recycled concrete aggregate (RCA) water absorption. Hardened cement pastes with three different water to cement ratios have been crushed in one to three steps with a jaw crusher to produce aggregate larger than 2 mm and ground with a disc crusher in order to produce particles lower than 150 µm. Water absorption tests and mercury intrusion porosimetry (MIP) were performed for the different resulting sizes. It was observed that the crushing procedure did not significantly affect the porosity of the aggregate. However, MIP performed on the powders showed differences in the pore size distribution compared with the monolith. This can better be attributed to a modification of the surface roughness of the particles than to a modification of their porosity. In all cases, the water absorption rate was the highest during the first 1 min after soaking in water. It was also observed that the morphology of the particles changed from a step of crushing to another. [ABSTRACT FROM AUTHOR]

In this work, the authors study the mixing proportions of similar materials for use in tests of models of fluid–solid coupling by using the orthogonal test on six factors at five levels. We used river sand and calcium carbonate as aggregates, white cement and chlorinated paraffin as cementing agents, and iron sand and silicone oil as regulators. The physical and mechanical parameters as well as the hydro-physical properties of similar materials were tested at different mixing proportions, and the sensitivity of the results to the influential factors was assessed by range and variance analysis. A linear regression-based analysis of 25 groups of results was then carried out on STATA software. Following this, the similar materials chosen for fluid–solid coupling based on the above tests were applied to the model test of water inrush in a karst tunnel. The results showed that the fluid–solid coupling similar materials of karst strata were prepared, the main factors influencing basic parameters variation of similar materials were obtained; a quantitative relationship between the influential factors and parameters of the materials was also constructed, and can be used to significantly improve the efficiency of testing; the similar materials developed here can satisfy the requirements of tests on models of fluid–solid coupling. This study has important reference value for research on similar materials for fluid–solid coupling in tests of models of karst tunnels. [ABSTRACT FROM AUTHOR]

We present a semiclassically approximate quantum treatment of solvation with the purpose of investigating the accuracy of the Caldeira–Leggett model. We do that by simulating the vibrational features of water solvation by means of two different approaches. One is entirely based on the adoption of an accurate ab initio potential to describe water clusters of increasing dimensionality. The other one consists of a model made of a central water molecule coupled to a high-dimensional Caldeira–Leggett harmonic bath. We demonstrate the role of quantum effects in the detection of water solvation and show that the computationally cheap approach based on the Caldeira–Leggett bath is only partially effective. The main conclusion of the study is that quantum methods associated with high-level potential energy surfaces are necessary to correctly study solvation features, while simplified models, even if attractive owing to their reduced computational cost, can provide some useful insights but are not able to come up with a comprehensive description of the solvation phenomenon. [ABSTRACT FROM AUTHOR]

The article discusses the importance of albuminuria screening in the detection and management of chronic kidney disease (CKD). Albuminuria, the abnormal loss of albumin in the urine, is considered a more sensitive indicator of kidney damage than proteinuria. The article presents the findings of the Towards Home-based Albuminuria Screening (THOMAS) study, which evaluated the effectiveness of home-based screening methods. The study found that urine collection devices were more reliable and had higher participation rates compared to smartphone applications. However, the overall cost-effectiveness and benefits of population screening for CKD remain uncertain, and further research is needed to determine the long-term impact of screening on preventing adverse outcomes. [Extracted from the article]

As of August 2023, the two U.S. Food and Drug Administration (FDA) official detection methods for C. cayetanensis are outlined in the FDA Bacteriological Analytical Manual (BAM) Chapters 19b (produce testing) and 19c (agricultural water testing). These newly developed detection methods have been shown to not always detect contamination when present at low levels. Yet, industry and regulators may choose to use these methods as part of their monitoring and verification activities while detection methods continue to be improved. This study uses simulation to better understand the performance of these methods for various produce and water sampling plans. To do so, we used published FDA test validation data to fit a logistic regression model that predicts the methods’ detection rate given the number of oocysts present in a 10-L agricultural water or 25 g produce sample. By doing so, we were able to determine contamination thresholds at which different numbers of samples (n = 1, 2, 4, 8, 16, and 32) would be adequate for detecting contamination. Furthermore, to evaluate sampling plans in use cases, a simulation was developed to represent C. cayetanensis contamination in agricultural water and on cilantro throughout a 45-day growth cycle. The model included uncertainty around the contamination sources, including scenarios of unintentionally contaminated irrigation water or in-field contamination. The results demonstrate that in cases where irrigation water was the contamination source, frequent water testing proved to be more powerful than produce testing. In scenarios where contamination occurred in-field, conducting frequent produce testing or testing produce toward the end of the season more reliably detected contamination. This study models the power of C. cayetanensis detection methods to understand the sampling plan performance and how these methods can be better used to monitor this emerging food safety hazard.

The paper presents the synthesis and thermal behavior of novel epoxy resins prepared from epoxidized castor oil in the presence of or without trimethylolpropane triglycidyl ether (TMP) crosslinked with 3-hexahydro-4-methylphtalic anhydride (MHHPA) and their comparison with a petroleum-based epoxy resin (MHHPA and TMP). Epoxidized castor oil (ECO) was obtained via in situ epoxidation of castor oil with peroxyacetic acid. The chemical structures of castor oil (CO), ECO, and epoxy matrix were confirmed using FT-IR and 1H-NMR spectroscopy. The morphological and thermal behavior of the resulting products have been investigated. Compared to petroleum-based resins, castor oil-based ones have a lower Tg. Anyway, the introduction of TMP increases the Tg of the resins containing ECO. The morphological behavior is not significantly influenced by using ECO or by adding TMP in the synthesis of resins. The dielectric properties of epoxy resins have been analyzed as a function of frequency (1 kHz–1 MHz) and temperature (−50 to 200 °C). The water absorption test showed that as Tg increased, the percent mass of water ingress decreased. [ABSTRACT FROM AUTHOR]

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Uranium is characteristic lithospheric component and is found nearly in all kinds of soils and waters; in any case, its quantity changes from water-to-water contingent on their cause. Subsequently, in the current investigation, the concentration of uranium in groundwater tests was estimated utilizing LED fluorimeter and the related health hazards appraisal was checked. The concentration of uranium ranges from 0.5 to 10.7 μg L−1 with average value of 2.76 μg L−1. The excess cancer hazard was seen in the scope of 1.416×10−6 – 30.309×10−6 with an average of 7.804 ×10−6. This mean estimation of the excess cancer risk in the Kanchipuram locale is less than the greatest adequate degree of l.67 × 10−4 as per AERB (2004). Consequently, there is no hurtful impact to the neighbourhood individuals who are devouring the water in the examination zone. The average cancer mortality and grimness chances were determined to show that the probability of cancer-causing chances related to water test and significant health was evaluated utilizing hazard quotient from chemical harmfulness of uranium. The values watched for hazard quotient in all areas in the examination are beneath the edge estimation of 1, as recommended by USEPA. This shows that there are no unsafe impacts on the nearby individuals in the investigation zone. [ABSTRACT FROM AUTHOR]

Bottles of breathing apparatus can be filled with a compressor and directly connected to “air banks”. During the filling of the bottles of breathing apparatus with high–pressure compressors, or with the help of “air banks”, there is an increase in pressure in time and the amount of compressed medical air in the bottle. The consequence is an increase in tension in the bottle material, which is in direct connection with the specified parameters. The intensity of the stress and the influence of the increase in pressure over time on the stresses of steel and composite cylinders are also identified using strain gauges. With tensometric measuring tapes, dilatation measurements were performed on a steel and composite bottle/cylinder of breathing apparatus (SCBA – self– contained breathing apparatus) with a cold–water test. They are used to measure local deformations on real structures. The aim of the research is to define the gradient of bottle filling speed, which ensures safety, and reliability of this procedure and which is influenced by parameters such as: bottle material, bottle correctness, correct airflow valve, temperature rise, minimum bottle filling time, etc. [ABSTRACT FROM AUTHOR]

Model tests and numerical calculations were adopted based on the New Yuanliangshan tunnel project to investigate the water pressure resistance of lining construction joints in high-pressure and water-rich karst tunnels. A large-scale model test was designed and conducted, innovatively transforming the external water pressure of the lining construction joint into internal water pressure. The effects of the embedded position and waterstop type on the water pressure resistance of the construction joint were analyzed, and the reliability of the model test was verified via numerical calculations. The results show that using waterstops can significantly improve the water pressure resistance of lining construction joints. The water pressure resistance of the lining construction joint is positively correlated with the lining thickness and embedded depth of the waterstop. In addition, the type of waterstop significantly influences the water pressure resistance of lining construction joints. The test results show that the water pressure resistance of the embedded transverse reinforced waterstop is similar to that of the steel plate waterstop, and both have more advantages than the rubber waterstop. The water pressure resistance of the construction joint determined via numerical calculations is similar to the model test results, indicating that the model test results have high accuracy and reliability. This study provides a reference for similar projects and has wide applications. [ABSTRACT FROM AUTHOR]

Aggregate–asphalt adhesion plays an important role in the water stability of asphalt concrete. In various test standards of different countries, it is evaluated via the subjective judgment of testers using the boiling water test. The subjective judgment in the test method is detrimental to the accuracy of the adhesion evaluation. However, there is no quantitative evaluation method for the aggregate–asphalt adhesion in existing studies. Moreover, the effects of aggregate shape on adhesion are also not discussed and stipulated. Hence, an innovative method based on the Chinese boiling water test and image processing technique is put forward to quantificationally evaluate the aggregate–asphalt adhesion. Moreover, the effects of aggregate shapes on adhesion are also investigated via the proposed method from a view of aspect ratio and homogeneity. Results show that the peeling of the asphalt membrane on the aggregate surface is more serious as the complexity of the aggregate shape increases after the boiling water tests, while the effect degree gradually decreases. The effect of aspect ratio on the peeling status of asphalt membrane is lower than that of aggregate homogeneity. [ABSTRACT FROM AUTHOR]

Based on the hidden karst exposed in Jurong Pumped Storage Power Station, combined with the field exploration data, the temporal and spatial development characteristics of hidden karst in the power station area are analyzed using the methods of specific solubility and specific corrosion, water chemical composition analysis, borehole television imaging, tracer test, and water pressure test. The results show that the karst development in the study area can be divided into three periods: pre-Cretaceous, Pleistocene, and modern karst. Karst development is controlled by soluble rock, non-soluble rock, and their combination, and the development direction is basically consistent with the fault strike. Karst caves are mainly distributed below the elevation of 100 m, with different shapes and scales and randomness. Non-soluble rocks and impure carbonate rocks are widely distributed in the study area, and surface karst is not developed. The underground karst caves are filled with red clay, and the rate of groundwater circulation is slow. The existence of geological bodies such as rock veins causes the groundwater levels to have obvious double-layer characteristics, which results in weak connectivity between karst caves. Although the karst in the power station area has a certain hydraulic connection with the surface water outside the area, the hydraulic connection of karst in the power station area is generally weak. The research results provide a scientific basis for the anti-seepage measures of underground powerhouses. [ABSTRACT FROM AUTHOR]

Low liquid limit clay has a low plastic index, displays poor strength, and is sensitive to water, and its mechanical qualities decline as the water content changes, making it difficult to employ directly in the construction process. Adding lime is a fantastic way to improve it. The influence of lime concentration on the road performance of low liquid limit clay is investigated in this research using a limit water content test, compaction test, and California bearing ratio test. The results show that the original plain soil does not meet the requirements of highway subgrade filling, and the basic properties of subgrade soil are improved to varying degrees after adding lime, resolving the problem regarding the original well-cultivated soil's inability to meet the requirements of construction. The plastic limit of the improved soil increased by roughly 3% as the lime content increased, but the maximum dry density decreased dramatically by 9.03%, 5.71%, and 5.98%, respectively. With an increase of 57.3% in lime content and compaction times, the California bearing ratio increases dramatically. The ideal moisture content rises as the lime content rises. The optimal dosage is 6%, according to a rigorous study of several performance metrics. [ABSTRACT FROM AUTHOR]

In this paper, mixtures with different proportions of lime, phosphogypsum, and red clay were prepared, and the road properties and micromechanisms of lime–phosphogypsum-stabilized red clay were investigated by unconfined compressive strength test, water stability test, swelling test, shrinkage test, XRD quantitative analysis, and scanning electron microscope analysis. The results showed that the unconfined compressive strength of the mix increased and then decreased with the increase of phosphogypsum content. With the increase of age, the growth was faster in the first 14 days and basically stabilized in the last 14 days. The mixture has poor water stability, large absolute swelling rate, and low linear shrinkage. The reason for the increase of strength is that the reaction of lime, phosphogypsum, and red clay produces ettringite, and the cementing substance gels form a three-dimensional mesh skeleton structure; the excess of ettringite will cause the skeleton to expand and break, and the strength decreases. [ABSTRACT FROM AUTHOR]

Durability of bituminous mixes is affected by presence or intrusion of moisture into it. The intrusion and amount of trapped moisture largely depend on the air voids present in the mixes. This study explores the combined influence of air voids and hydrated lime (HL, as anti-stripping agent) on moisture-induced damage of bituminous mixes prepared from two different aggregate sources. The aggregates used in the study are siliceous sandstone and basalt. Tensile Strength Ratio (TSR) test was used to determine the moisture susceptibility of bituminous mixes. A higher value of TSR depicts that the mixes are more moisture resistant. TSR was reaffirmed to be lowest at an air void range of about 5% to 13% which is termed as pessimum air void range. At this air void range, moisture gets trapped within the mix, resulting in moisture-induced damage. TSR results showed that bituminous mixes prepared with siliceous sandstone is more susceptible to moisture-induced damage as compared to mixes prepared with basalt. Boil water test reconfirmed the results. Use of HL in bituminous mixes improved its moisture-induced damage resistance only marginally. Thus, moisture-induced damage control at pessimum air void range using anti-stripping agent is not always sufficient. Observations show that air void plays a critical role in moisture-induced damage and control of air void during construction needs to be ensured. [ABSTRACT FROM AUTHOR]

This research investigates protective effects of vapour phase corrosion inhibitors (VpCI) tested in laboratory conditions. Such tests are required to control the production quality and to provide for high-quality protection of products during exploitation. There are three different tests run to obtain results on effectiveness of protective effect of VpCIs (Razor Blade Test, Water Drop Test and VIA Test). Each test differs in its defined performance procedure, as well as in evaluation of the obtained results, yet all three tests confirmed that vapour phase corrosion inhibitors provide adequate protection of the material exposed to an aggressive atmosphere. Therefore, it is justified to use vapour corrosion inhibitors as a protection mechanism when designing surface protection technology. [ABSTRACT FROM AUTHOR]

Clay-based barrier wall has been diffusely employed as vertical barriers. Nevertheless, there were few project practices of these walls in China. And few research have been performed to study the impact on the permeability of the addition of domestic bentonites. To solve this problem, the influences of bentonite level on hydraulic conductivity, porosity and clay-bound water of soil-bentonite admixtures have been assessed employing a flexible-wall test and water centrifugal dewatering experiment with various bentonites. The outcomes revealed that as barrier walls are constructed by blending bentonite and Fujian standard sandy soil, there is a critical bentonite level of the smallest porosity. If the bentonite level is less than the critical bentonite content, hydraulic conductivity is reduced quickly, while if the bentonite level is greater than the critical bentonite content, hydraulic conductivity is reduced gently. Additionally, as the bentonite level grew, the clay-bound water centage of the admixtures continually improved. Supposing that the clay-bound water enclosed the clay grains, a near computation approach of the effective porosity is put forward and showed that the effective porosity decreased with bentonite content. Additionally, an exponential relationship was found between the effective porosity and the permeability. [ABSTRACT FROM AUTHOR]

The critical Reynolds number for dispersed bubbly two-phase flows, gas in liquid, was experimentally investigated. In this experiment, the gas was air and the liquid was water. Water flowed upward through a vertical, translucent pipe, and air was introduced into the water prior to the test section by means of a basswood microbubbler. Dye was injected into the water to indicate when the flow transitioned from laminar to turbulent. Mixtures with gas volume fractions up to 10% were tested, and the Reynolds numbers for which the flow transitioned from laminar to turbulent were recorded. The data showed that the critical Reynolds number fell to roughly one-half of its original single-phase liquid value once the gas volume fractions exceeded 0.1%. These results indicate that the presence of even small amounts of bubbles causes pre-mature transition to turbulence. [ABSTRACT FROM AUTHOR]

Building on a previously developed workflow for rapid and sensitive pathogen detection by qPCR, this work has established a sample treatment strategy that produces consistent quantification efficiencies (QEs) for Campylobacter jejuni against a complex and highly variable sample matrix from a suburban river. The individual treatments most effective at minimizing the inhibitory effects of the sample matrix were pH buffering with HEPES (50 mM, pH 5.7) and addition of the surfactant Tween 20 (2% v/v). Unexpectedly, sample acidification (pH 4–5) resulting from the use of aged Tween 20 that had undergone partial hydrolysis, appeared to play a key role in enhancing QE. This effect could be replicated by direct pH adjustment with dilute hydrochloric acid and may be linked to the solubilization and removal of inhibitory particles at an acidic pH. While the effectiveness of each individual treatment method varied, a combined treatment of either HEPES buffer + Tween 20, or direct pH adjustment + Tween 20, consistently produced QEs of 60%–70% and up to 100%, respectively, over a sampling period of one year. The consistency and scalability of this workflow make it a suitable alternative to culture-based ISO methods for detecting Campylobacter spp. [ABSTRACT FROM AUTHOR]

Estimating the downhole leaks is very important in order to evaluate the well performance and assess the wellbore integrity. Different approaches can be used to estimate the downhole leaks such as temperature surveys, noise logs, and corrosion logs. However, most of the available techniques require downhole measurements which will increase the operational cost and time. This study presents an integrated approach for predicting downhole leaks based on surface measurements, which will reduce the cost and effort significantly. The proposed method was implemented on actual field data, where reasonable accuracy was observed. In this work, the casing leaks were quantified by diagnosing the pressure and flow rate profiles at the surface, without using any downhole flow spinner. Three main steps were used to estimate the downhole leaks; building the inflow performance relationship (IPR) model, predicting the reservoir productivity/injectivity index, and calculating the pressure profiles along the wellbore using the nodal analysis technique. The suggested approach can be used to predict the downhole leaks for production wells as well as injection wells. In this study, the proposed technique was tested for a water injection well, where the fluid leakage was detected and the leak depth was determined. The studied well suffers from severe corrosion problems, that resulted in downhole leakage. For the well under investigation, the leakage rate is 8500 barrels per day (bpd) and the expected leakage depth is around 1374 ft., based on the wellbore survey. Applying the proposed approach showed that the leak rate is 8831 bpd and the leakage depth is 1380 ft. Therefore, the estimations errors are 3.89% in the flow rate and 0.43% in the leakage depth. Overall, an integrated approach is proposed to detect the downhole leaks, the proposed method has been analytically derived and tested using actual field data. The presented method uses surface measurements without a need to stop the production or injection operations. The new method showed very acceptable prediction performance, where estimation errors of 3.89 and 0.43% were obtained for the leakage rate and depth, respectively. [ABSTRACT FROM AUTHOR]

In this work is presented a repeatability study applied to a cookstove based on wood pellets gasification (19.03 MJ/kg). The analysis is carried out under a modified water boiling test (WBT 4.2.3). The repeatability of the gasification-based cookstove was assessed by means of two methodologies, such as the variation coefficient (CV, %) and the analysis of variance (ANOVA). The answer variables evaluated under repeatability were the efficiency (η, %), power (P, kW), fuel consumption (FC, g/min), fuel specific consumption (SFC, g/L), energy specific consumption (SFEC, kJ/L), and energy specific consumption per unit time (SFCT, kJ/L-min). By the CV analysis, the global average CV was 4.69% ± 0.87%. Therefore, as CV ≤ 5%, it is concluded that the gasification based cookstove is statistically repeatable. Concerning the ANOVA, the P-values of the variables studied were higher than 0.05 (P>0.05), thereby, it is stated that the improved cookstove is repeatable with a confidence level of 95%. Consequently, it is highlighted that the average thermal efficiency reached by the cookstove is ~29% ± 2.25%, with a confidence level of 95%. This thermal efficiency value is comparable with other biomass cookstoves based on gasification reported in the literature with values between 16 and 38%. The methodology and the results of this work constitute a theoretical foundation for assessing future developments of biomass cookstoves since the results reliability found in the prototypes tested at the laboratory level can be quantified and analyzed. [ABSTRACT FROM AUTHOR]

For the characterization of heterogeneous aquifers, transient hydraulic tomography (THT) was proposed as a promising method to obtain the distribution of hydraulic parameters with satisfying spatial resolution using different approaches. These include hydraulic travel time, attenuation inversions, thermal tracer tomography, and geostatistical inversion with successive linear estimator (SLE). For the same hydrogeological test, different inversion methods tend to use different sub-data sets to obtain different hydraulic parameters. Up to now, however, few studies have focused on revealing the respective characteristics of these inversion methods and attempted to improve the accuracy of aquifer characterization by bridging the shortcomings of the inversion methods. The main objective of this study was to evaluate the utility of multiple inversion techniques on aquifer heterogeneity characterization. A series of warm water injection tests were first simulated in a fluvial aquifer analogue outcrop. The calculated head and temperature datasets from these tests were fully utilized to reveal the aquifer heterogeneity by using all of the four above-mentioned inversion methods. The results show that the thermal tracer tomography, hydraulic travel time, and attenuation tomography characterized the high permeability zones more accurately within the well area, whereas the geological statistical method tended to depict the overall distribution of K values for a larger area. By comparison analysis and combinations of the individual inversion results, the scientific and economic complementarity can be studied and some valuable advice for the choice of different inversion methods can be recommended for future practices. [ABSTRACT FROM AUTHOR]

The historical stone heritage that we inherit must be passed on to future generations, not only in the same conditions that we found it but, if possible, in better ones. Construction also demands better and more durable materials, often stone. The protection of these materials requires knowledge of the types of rocks and their physical properties. The characterization of these properties is often standardized to ensure the quality and reproducibility of the protocols. These must be approved by entities whose purpose is to improve the quality and competitiveness of companies and to protect the environment. Standardized water absorption tests could be envisaged to test the effectiveness of certain coatings in protecting natural stone against water penetration, but we found that some steps of these protocols neglect any surface modification of the stones, and hence may not be completely effective when a hydrophilic protective coating (i.e., graphene oxide) is present. In this work, we analyze the UNE 13755/2008 standard for water absorption and propose alternative steps to adapt the norm for use with coated stones. The properties of coated stones may invalidate the interpretation of the results if the standard protocol is applied as is, so here we pay special attention to the characteristics of the coating applied, the type of water used for the test, the materials used, and the intrinsic heterogeneity of the specimens. [ABSTRACT FROM AUTHOR]

Selenium is a trace element that can be poisonous in small quantities. The aim of this study was to analyze the change in the content of selenium in drinking water, raw water, as well as treated and raw wastewater in an annual cycle in the city of Szczecin. The concentration of Se in samples was determined using the spectrofluorometric method at a 518 nm emission wavelength and a 378 nm excitation wavelength. The amount of selenium in drinking water ranged from

The abrasion resistance is one of the crucial parameters to consider when evaluating natural stone for use in public infrastructure with light traffic. The assessment and evaluation of abrasion parameters can be carried out according to the EN 14157 standard, using two typical natural stones from different sources in order to compare the necessary parameters. The parameters will be analysed in correlation with other factors in order to find optimizations. The results showed a significant correlation coefficient between the dry sample and water saturation tests. This suggests that the abrasion resistance of natural stone when dry is closely related to its resistance when saturated with water. This information is valuable in selecting appropriate natural stone materials for public infrastructure, as it provides insights into how the materials will perform under different conditions. In public squares, natural stone is often used as paving material because of its durability, resistance to weathering, aesthetics and other parameters. However, different types of natural stone have different levels of abrasion resistance, which can affect their suitability for use in public squares. [ABSTRACT FROM AUTHOR]

Neutron thermalization leads to the complexity of the scattering cross-section calculation, which influences the accuracy of the neutron transport calculation in the thermal energy range. The higher precision of thermal scattering data is demanded in the small modular reactors (SMRs) design, especially for small-sized PWRs and SCWRs. Additionally, the thermal neutron scattering problems in supercritical water have not yet been solved. In this study, the thermal neutron scattering problems in subcritical water are tested. Based on thermal neutron scattering theory, the GA model and IKE model were analyzed. This work selected the corresponding input parameters, such as the frequency spectrum, the discrete oscillator energy, weight parameters and so on, as well as preliminary studies on how to calculate the thermal scattering data for HinH2O to accomplish the calculation at various temperatures by developing LIPER code. The deviation between the calculated and reference results, which were both obtained by the Monte Carlo code, COSRMC, was below 0.2 pcm. The deviation of the scattering cross-section between the calculation results and reference was below 0.1%, indicating the reasonability of this study's thermal scattering data calculation. [ABSTRACT FROM AUTHOR]

Various methods and processes are applied in order to manage losses in water distribution systems. In order to apply these methods and achieve the expected benefits, the basic data in the system should be measured and monitored regularly. In this study, a new model was developed to analyze and evaluate the current levels of basic data required for the sustainable execution of water loss management processes. For this, a total of 18 basic components covering water loss management were considered. A scoring structure has been developed to evaluate the current status and application level of these components. In this scoring structure, the components are scored gradually to define the current level of application. The developed model was applied to three water utilities and tested with real field data. The current situation, weaknesses and strengths of each administration are defined within the scope of basic data. Targets to be achieved gradually for each component were determined based on these analyzes. It is thought that this study will constitute a reference for decision makers and technical personnel in administrations, especially in water loss management. [ABSTRACT FROM AUTHOR]

The existence of karst compromises the safety of underground engineering, especially during tunnel excavations. Karst conduits are uncovered through tunnel excavations, which may lead to a water–sand inrush disaster. Taking a vertical karst conduit as an example, the process of water–sand inrush through a karst conduit could be viewed as being similar to the process whereby a water–sand mixture flows through the discharge opening of a storage bin. In this study, based on force analysis of a non-aqueous sand body above a karst conduit, the limiting diameter of the karst conduit under force equilibrium was obtained. Considering the effect of water on aqueous sand bodies, the criterion of water–sand inrush was established. We aimed to study water–sand migration and inrush through vertical karst conduits in order to obtain the distribution of the water pressure near a vertical karst conduit, and to explore the relationship between the conduit size, water pressure, and water–sand flow rate; therefore, a simulated testing system for analyzing water–sand inrush through a vertical karst conduit was developed. When the water pressure in the testing chamber was close to the critical head pressure of the water–sand inrush, the water–sand inrush exhibited a pattern of instability—migration—deposition—stability. When the water pressure in the testing chamber exceeded the critical head pressure, the water–sand flow increased first and then stabilized over time. With the increase in the set values of the water pressure and conduit size, the steady flow of the water–sand mixture increased gradually. When the karst conduit was opened suddenly, the actual water pressure in the testing chamber decreased significantly, due to the water–sand mixture flowing out of the testing chamber and the water supply lagging behind. With the stabilization of the water–sand flow, the actual water pressure gradually tended towards stability, but it was still lower than the initial set water pressure. When the karst conduit was opened, the values of the water pressure monitored by the pore pressure gauges all clearly decreased. With the stabilization of the water–sand flow, the water pressure gradually became stable. With the increase in the distance between the pore pressure sensor and the karst conduit, the water pressure values all increased gradually. These test results are significant for further studies of the formation mechanisms of water–sand inrush through vertical karst conduits. [ABSTRACT FROM AUTHOR]

Surface Water Absorption Test (SWAT) has long been proposed as a non-destructive testing device for evaluation and grading of the quality of the cover concrete and standardization of SWAT is still in process. In this study, the acceptability and validity of a new water sorptivity index of the SWAT method - the coefficient of surface water absorption (CSWA), are appraised by a correlative assessment between CSWA and the coefficient of air permeability (kT values) measured by the Torrent's double chamber air permeability device. The tests were conducted on fourteen different kinds of concrete at different ages, produced with three different cement types, four water-to-binder ratios, and four curing conditions. The results revealed a good correlation between CSWA and kT for both the specimens with uniform moisture content and the ones with varying degrees of moisture gradients. The findings validate the CSWA as an effective quality control index during design as well as a durability quantifier for evaluating the water absorption resistance of in-situ concrete structures. [ABSTRACT FROM AUTHOR]

This paper deals with the resistance, towing, seakeeping, and open water propeller tests of an innovative tourist submarine model. Tests were performed in a 276 m long towing tank. As the submarine model is a complex structure composed of various parts attached to the pressure hull, the largest possible model, in the scale of 1:5.0, was produced, considering the towing tank depth and the capabilities of the measurement equipment. Resistance tests were performed in deep water and on the surface in calm water. The tested speed range in both cases was up to 5.5 knots. To ensure the avoidance of free surface effects, resistance tests in deep water were performed for different draughts and then extrapolated to infinite water depth. Smaller effective powers were found for the surface condition. The results are compared to an independently performed computational fluid dynamics (CFD) analysis using OpenFOAM. A fair agreement between the experimentally and numerically predicted effective power is found, while the reasons for the differences found are explained. The free submarine model was towed with a rope performed for the speed range 1.7 kn–3.5 kn, and the towing force in the rope was measured. Seakeeping tests in irregular beam waves at zero speed were performed to check the flooding risk on open hatches. Open water tests of the main thrusters for propelling the submarine were conducted, indicating that both power demand and propeller thrust are slightly larger compared to the initial estimates. [ABSTRACT FROM AUTHOR]

Water is very crucial for surviving life of all human being and animals. Without water nobody can be survived. The existing manuscript associated with Anchar Lake water. Water is vulgarized by unwanted materials. Water quality tests and reevaluate of attributes. Scrupulous substances are: Dissolved Oxygen (DO), Total Alkalinity (TA), Electric Conductivity (EC), Potential of Hydrogen (pH), Phosphate (P), Total Dissolve Solids (TDS), Total Hardness (TH) and Chloride thereupon. The attributes are statistically interpreted using cluster analysis, correlation matrix, factor analysis and ANOVA techniques and interpret that the Lake water is unsuitable for drinking. Experimental data shows that most of the attributes does not satisfy the desirable limits prescribed by BIS. Hence the Anchar Lake water is not suitable for drinking purposes. [ABSTRACT FROM AUTHOR]

Total alkalinity is a pivotal water quality parameter dictating the response of natural waters to acid–base system perturbations such as ocean acidification and acid mine drainage. Its value as a biogeochemical and ecological variable is enhanced not just by high measurement quality, but also by measurement accessibility. This research demonstrates an instrument that advances the accessibility of high‐precision, high‐accuracy total alkalinity measurement using open‐source, and low‐cost instrumentation. Repeated testing of water samples from Lake Superior demonstrated a measurement precision (standard deviation or SD) of 3.0 μmol kg−1. Analysis of standards and reference materials demonstrated an uncertainty of 5.3 μmol kg−1 as well as robustness to freshwater and saltwater matrices. This instrument adds to the wealth of inorganic carbon measurement technologies in marine and lacustrine settings and stands to enhance the ability of both communities to generate accurate and accessible measurements of total alkalinity. [ABSTRACT FROM AUTHOR]

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