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The present work is an attempt to carry on analytical work on a biodegradable cellulosic material obtained from the fibre of a plant which is scientifically known as Grewia Optiva. In this study, 125 µm particle size of Grewia optiva fibres was used as a filtration loss controlling agent in drilling fluid. The Grewia Optiva mud samples were hot rolled at 100 °C for 16 h and it was observed that the said fibre at 5% concentration (w/v) has reduced the low pressure–low temperature (LPLT) filtration loss of drilling mud by 72.5% under the differential pressure of 100 psi. On further assessment vis a vis comparative analysis with available market products like carboxy methyl cellulose-low viscosity grade (CMC-LVG) and polyanionic cellulose-low viscosity grade (PAC-LVG), it was found that addition of CMC and PAC-dLVG at 1.4% (w/v) in reference mud, the LPLT filtration loss was reduced by 70% and 70.6%, respectively. Use of 5% GOFP in the reference mud, the high pressure-high temperature (HPHT) filtration loss of drilling fluids was reduced by 69.2% at 100 °C temperature and 500 psi pressure. The thickness of filter cake was reduced by 41.1% after the addition of 5% GOFP in the reference mud. While the conventional fluid loss reducing agents such as CMC and PAC, both at 1.4% concentration have reduced the HPHT filtration loss by 63.46% and 64.6%, respectively, as compared to reference mud. This is indicative of a valid filtration loss control potential of Grewia optiva fibre powder.

Made available in DSpace on 2022-04-28T19:43:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Background: Resistance training has proven to be an excellent method for counteracting aging physical dysfunctions. However, its application in the liquid environment is not yet fully elucidated. Aim: To investigate the effects of water-based resistance training (WBRT) with the concentric phase performed as fast as possible, compared to conventional resistance training (CRT), on physical functional capacity, muscle strength, and body composition in older women. Methods: Thirteen healthy older women participated in the WBRT and 11 in the CRT. Estimation statistics focused on the effect size of the experiment/intervention were used. We also analyzed the intervention effect based on the percentage delta between WBRT and CRT. Results: The WBRT group showed a negative large effect (d = − 0.922; p = 0.0274) for the timed up and go, and a large effect for chair rise in 30″ and the elbow flex test (d = 1.58; p = 0.0012; d = 2.8; p = 0.01) respectively. Intervention comparisons based on the delta percentage between WBRT and CRT presented an intermediate effect (d = 0.606; p = 0.157) for the stair climb, a large effect (d = 0.988; p = 0.0282) for the timed up and go, and a large negative effect [d = − 1.32 (90.0% CI − 1.92, − 0.646); p = 0.0038] for the elbow flex test. Concentric extensor-flexor peak torque (60°/s) showed an intermediate effect (d = 0.749; p = 0.0876; d = 0.65; p = 0.122 respectively). Body fat (%) demonstrated an intermediate effect (d = 0.523; p = 0.234). Conclusion: WBRT with the concentric phase performed as fast as possible was able to improve physical functional capacity and maximal knee extension strength of older women. Laboratório de Estudo do Desempenho Humano Universidade Federal do Amazonas, Av. Gen. Rodrigo Otávio. 5614, Coroado Programa de Pós Graduação Stricto Sensu em Ciências do Movimento Humano Faculdade de Educação Física e Fisioterapia Universidade Federal do Amazonas Projeto de Extensão Universidade Aberta da Terceira Idade Universidade Federal do Amazonas Centro de Estudo e Laboratório de Avaliação e Prescrição de Atividade Motora Universidade Estadual Paulista Centro de Estudo e Laboratório de Avaliação e Prescrição de Atividade Motora Universidade Estadual Paulista

Drilling operation is considered an extremely high-cost business within the petroleum industry. The cost of drilling fluid represents 15–30% of drilling operations. Measurements of all drilling mud properties were conducted in aged and fresh conditions. Furthermore, high pressure and temperature (HTHP) API filtration experiments were executed, as well. The findings were used as a reference comparative point for three concentrations of peanut shell powder (PSP) to comprehend the influence of various concentrations of PSP on the characteristics of spud mud. The findings of this experimental research revealed that the cheap and biodegradable PSP can be exploited as a new multi-role additive to develop filtration and viscosity under surface and sub-surface conditions. Moreover, the study findings demonstrated the suitability of PSP to replace or at minimum substitute traditional and non-degradable chemicals used in the petroleum industry (e.g., lignosulfonate, chrome-lignosulfonate, resinex, etc.). In addition to the benefit of using PSP as a multifunctional additive, it is cheap, easy to prepare, locally available and attainable in large quantities, and friendly to the environment. In summary, PSP has a possibility to be applied in the oilfield as it withstood 79 °C (175 °F) temperature and 30 h of aged time. The application of PSP in the drilling process can mitigate the detrimental impacts of the non-biodegradable conventional chemical materials on personal health safety and the environment in addition to decreasing the overall cost.

This work investigates the efficacy of a biodegradable natural product, litchi leaves powder (LLP) as a filtration loss control agent in the water-based drilling fluid formulations. In order to evaluate the potential of litchi leaves powder (LLP), a strict protocol of experimentations according to API (American Petroleum Institute) standard has been followed. The experimental outcome showed that before hot rolling and after hot rolling of mud samples at 100 °C it was observed that 3–5% Concentration of LLP significantly increased the rheological parameters such as PV, YP and gelation of drilling fluid as compared to reference mud. Also, LLP reformed the filtration loss control characterization, suggesting a better biodegradable fluid loss reducing agent. After hot rolling at 100 °C for 18 h, the water-based drilling fluid with LLP as an additive showed a marked reduction in filtration control property as compared to reference Mud (RM). Experimental results concluded that 5% concentration of LLP significantly reduced the filtration loss of drilling fluid by 70.6% as compared to reference mud under the influence of 100 psi pressure. However, the conventional fluid loss additive CMC (LVG) reduced the filtration loss by maximum 67.5% as compared to reference mud. Therefore, LLP can be used as an alternative to CMC (LVG) in water-based drilling fluid with a maximum subsurface temperature of 100 °C.

The purpose of this study was to evaluate the controlled-release properties of nutrients from coconut water-based hydrogel. Hydrogels were prepared at varying proportions of gellan and xanthan gums such that the total weight of the gelling agents for all 11 formulations was 1% (w/w) in coconut water. The formulation of the hydrogel was selected using gravimetric analysis by evaluating the dissolution weight of the hydrogel in simulated gastric fluid and simulated intestinal fluid. Interestingly, hydrogel with 0.7% gellan gum and 0.3% xanthan gum showed the most tolerance towards simulated gastric and intestinal fluids over a 1-h period. The in-vitro release study was performed in simulated gastric fluid and followed by simulated intestinal fluid for about 2 h. The trend of release profile showed that the hydrogel had the ability to sustain the nutrients release over a period of 1 h. After 75 min, the release trend was static indicated the nutrients was released from the hydrogel. In conclusion, a coconut water-based hydrogel formulated with 0.7% of gellan and 0.3% of xanthan gum has demonstrated its controlled-release property as evidenced by its effectiveness in the sustained release of nutrients over a period of 1 h.

Water-based lubricant is regarded as an important substitute for the oil-based lubricant when used in improving the tribological properties. Additives are urgent required in water-based lubricants as their disadvantages of poor lubricating properties. In the present work, a new additive containing S, P, Cl active element was synthesized, and the tribological properties were evaluated by using a four-ball tester. The impact of temperature on the tribological properties of water-soluble lubricant was also studied. The worn surfaces were analyzed by X-ray absorption near-edge structure (XANES) spectroscopy. The results show that the synthesized additive exhibit better tribological properties than oleate solution at higher load. XANES spectroscopy indicates that the compositions of tribofilms changed with the temperature. The different composition of the tribofilm has a great influence on tribological behavior.

The proper selection of drilling fluids formulations and its treatment has always been a challenge and requires a great effort to ensure optimum drilling performance. The objective of this paper is to assist the mud engineer in selecting the water-based drilling fluid formulations that are best suited for a certain application. To achieve this target, the field practices were combined with the literature to study the most practiced water-based drilling fluid recipes used for onshore gas applications in the Middle East (i.e., spud mud, high-bentonite spud mud, salt/polymer mud, and high-overbalanced mud). From both field practices and deep literature review, it is recommended that both spud mud and high-bentonite spud mud be prepared and pre-hydrated for 4–6 h before a well spud. Also, it is important to add detergents with high-viscosity sweeps to avoid the bit balling and maintain the gel strength. While for salt/polymer mud, the regular addition of sodium sulfite is necessary for polymers stabilization, and the efficient solids control equipment performance is essential. To avoid the solids sagging issues associated with drilling high-pressure high-temperature deep gas reservoirs, it is recommended to either uses sag resistance materials, micronized weighting materials, or a combination of different weighting materials. The high-overbalanced mud is the most effective and efficient type when drilling a combination of natural fractured depleted gas reservoirs with high-pressure gas reservoirs.

A green synthetic route to the facile one-pot multicomponent synthesis of pyrano[2,3‐d]pyrimidines and pyrido[2,3‐d]pyrimidines have been developed using magnetized deionized water (MDW) as a green solvent under catalyst-free conditions. All reactions carried out in a short period of time and the products are obtained in high-to-excellent yields. The developed synthetic technique offers numerous advantages including eco-friendly, clean synthesis, simplicity, low cost, short reaction times, high reaction yields, and easy workup compared to the traditional synthetic method. Moreover, the reaction rates were followed spectrophotometrically by monitoring the changes in the absorption spectrum of the reaction mixture in ordinary deionized water and MDW.

The present experimental analysis targeted on the preparation of water based (Al2O3-SiC-TiO2) ternary hybrid nanofluids by the mistreatment of two-stage methodology. Each vol. fraction sample of ternary hybrid nanofluids consists of an equal proportion of Al2O3-SiC-TiO2 nanoparticles for this analysis. The result for the dynamic viscosity of ternary hybrid nanofluids was examined for a temperature range of 35–40 °C and within a vol. fraction range of (0.01–0.1%). Analysis extended to the morphology characterization study through SEM image, together with an EDX analysis for 0.1% vol. fraction ternary hybrid nanofluid. Furthermore, based on the supported results, a new correlation was projected for the dynamic viscosity of ternary hybrid nanofluid, and also compared with the relevant literatures. The results revealed that the rise in vol. fraction, contains a larger role in increasing the interior resistance of fluid and the low vol. fractions have a weaker result on the viscosity of ternary hybrid nanofluids. The best relative consistency was discovered within 0.1% vol. fraction and, consistent with the obtained results, the margin of deviation within the intervals of ±2.6%.

Dynamism associated with drilling conditions such as during well completion may necessitate switching between overbalanced drilling and underbalanced drilling in the same drilling operation. One possible way to easily facilitate this is to use appropriate drilling fluid suitable for any drilling condition. A multifunctional drilling fluid additive gives the opportunity to develop drilling fluids that have the same base composition but different functionality. In this study, a novel additive was developed via alkaline extraction and hydrolysis of date pits components in a freezing-defreezing technique. This additive was tested in a water-based bentonite drilling fluid which was characterized in terms of density and filtration properties. The results showed that the drilling fluids containing this novel additive have low filtration properties attributed to products of complete alkaline hydrolysis of fatty acids and amino acids, and the unreacted alkali. The drilling fluid containing the novel additive when neutralized resulted in another drilling fluid of higher filtration properties and lower density. The potential of the un-neutralized drilling fluid to form a thin filter cake of low permeability makes it a suitable candidate for overbalanced drilling while the synergistic effect of both the low density and high filtration property of the neutralized drilling fluid favours its efficacy for underbalanced drilling. The multifunctionality of this novel additive derives from its potential to be used to develop both the overbalanced drilling fluid and underbalanced drilling fluid.

Although metal-organic frameworks (MOFs) show numerous advantages over other crystalline materials, their industrial relevances have been impeded owing to their many drawbacks such as environmental impacts and economic costs of their synthesis. A green preparation pathway could greatly reduce the environmental costs, energy, and the need for toxic organic solvents, and consequently reduce the production cost. Thus, the most desirable synthesis route is the replacement of harsh organic solvents with aqueous solutions to abate environmental and economic impacts. This review summarizes recent research advancements of water-based routes for MOF synthesis and gives a brief outline of the most prominent examples. The challenges and prospects of the commercialization of promising MOFs in the future are also presented. This study aims to offer necessary information regarding the green, sustainable, and industrially acceptable fabrication of MOFs for their commercial applications in the future.

Synergistic effect of MWCNTs-COOH and Ag nanoparticle on improving thermal conductivity of hybrid nanofluid has been explained experimentally in this paper. Different concentrations of MWCNTs/water nanofluids (0.004, 0.008, 0.04 and 0.16 vol%) were used and mixed with (0.04 vol%) Ag nanoparticle to prepare hybrid nanofluid. TEM was employed for confirming the size of MWCNTs and Ag nanoparticles in base fluids. Furthermore, SEM and XPS were utilized to characterize the prepared hybrid nanofluid. The hybrid nanofluids’ thermal conductivity was measured in varying volume fractions at 20–50 °C temperatures. As shown by the results, the ratio of thermal conductivity of hybrid nanofluids is increased in a nonlinear manner as the concentration and temperature increase. It was seen that the hybrid nanofluid’s thermal conductivity having 0.04 vol% Ag nanoparticles and 0.16 vol% MWCNTs was synergistically improved by 47.3% in comparison with thermal conductivity the water base fluid. In the end, new thermal conductivity ratio correlation was suggested on the basis of the empirical data. Comparisons of correlation output and experimental thermal conductivity ratio data showed high accuracy and capability in modeling of thermal conductivity ratio data.

This study looks at the effects of different kinds of nanoparticles including AL2O3, SiO2, and CuO on the design of a solar flat plate collector in different volumetric concentrations. Water was used as the base fluid, and optimal SFPC parameters were obtained for each of the nanofluids. Both the efficiency and total annual cost were selected as objective functions, and the optimum Pareto fronts were compared with those of the base fluid. The results show a significant enhancement in both the efficiency and TAC for all the studied nanofluids compared with the pure water as the working fluid. The efficiency improved by 4.47%, 4.65%, and 5.22% in the cases of AL2O3, SiO2, and CuO compared with base fluid with a fixed TAC of 67 $ year−1. With a fixed efficiency of 0.564, TAC decreased by 25.45%, 25.87%, and 27.88%, respectively. The optimum design parameters show that lower heat transfer surface area and insulator thickness are needed for CuO compared with the other cases, followed by SiO2, AL2O3, and the base fluid. In the optimum conditions, a lower particle volumetric concentration is required for CuO, followed by Al2O3 and SiO2.

We studied the effect of polymer design on the interfacial structure and physical properties of polymer films in water based on a poly(vinyl ether) platform with hydrophilic side-chains to construct bioinert interfaces. Initially, we explored how to prepare hydrophilic surfaces using poly(vinyl ether)s, utilizing the preferential segregation of a rubbery component in a diblock copolymer film with a glassy component, crosslinking a hydrophilic polymer, and designing an interfacial modifier with a special architecture. Characterizing the interfacial structure and physical properties of the obtained polymer films in water revealed that a small difference in the side-chain structure significantly impacts the resultant interfacial properties of the polymers, leading to excellent blood compatibility. Furthermore, we demonstrate that swelling behaviors, which are related to chain dynamics, at the water interface play a key role in determining bioinert properties. The effect of polymer design on the interfacial structure and physical properties of polymer films in water based on a poly(vinyl ether) platform with hydrophilic side-chains was examined to construct bioinert interfaces. Hydrophilic surfaces were prepared by utilizing the preferential segregation of a rubbery component in a diblock copolymer film with a glassy component, crosslinking a hydrophilic polymer, and designing an interfacial modifier with a special architecture. Interfacial structure and physical properties controlled by polymer design play important roles in determining bioinert properties.

In the 1980s, a new class of thickeners, i.e., associative thickener (AT), was introduced for water-based coatings to improve their rheology. Principally, they work by associating with polymer particles present in the paint. Manufacturers of ATs provide some generic guidelines to choose them based on economy, regulatory restrictions, and polymer type; however, it is very difficult to choose suitable ATs until and unless their interactions with polymer particles are studied by rheology. This article focuses on developing a rheological approach to identify a suitable AT for a paint formulation. In this approach, a rheology viscosity curve was used on AT–emulsion polymer mix and AT–emulsion polymer–surfactant mix to short-list a suitable AT. Subsequently, the shortlisted ATs were tested in the paint formulation to study their efficacy. Commonly used, hazardous air pollutants (HAPs)-free, commercially available ATs, viz. hydrophobically modified ethoxylated urethane thickener (HEUR) and hydrophobically modified poly(acetal- or ketal-polyether) thickener (HMPE), were selected to study their interaction with a unique surfactant-stabilized acrylic–polyurethane hybrid emulsion. A range of acrylic–polyurethane hybrid emulsions were prepared by increasing the polyurethane content in the emulsion. As the polyurethane content increased in the emulsion polymer, the thickening efficiency of AT decreased.

Paper has been proposed as an alternative substrate material for graphene-based strain gauges due to its high flexibility and accessibility when compared to the conventional substrates such as polymer that is not only rigid but also not recyclable. In the fabrication of graphene-based strain gauges on paper, inkjet printing is commonly used as the main deposition method of graphene on paper as this process allows a systematic control of strain gauge resistance by manipulating several factors such as print passes and drop spacing. However, the availability of inkjet printers that allows the printing of graphene solution is an issue as industrial inkjet printers can be obtained only at a premium price while modification of commercial inkjet printers is a must to replace the original ink with graphene ink. To counter this issue, a commercial photo paper has been used for the first time as a substrate during vacuum filtration of graphene solution for layer–layer assembly of strain gauges on paper. With the resulting gauge factor of up to 83 at the maximum and minimum strain of 1.4% and 0.03% (sensitivity of 1.25%) respectively, the fabricated strain gauge from photo paper shows the potential of paper to be used as a component in the future wearable device. Meanwhile, the advantages of using vacuum filtration as the selected technique for the deposition of graphene meanwhile are demonstrated in this work by varying the gauge factor through controlling the graphene deposition volume.

In this study, the ZnO quantum dots (QDs) water-based fluorescent anti-counterfeiting ink was prepared with the polyvinylpyrrolidone (PVP) content of 0.15–0.17 g/mL, the ZnO QDs concentration of 4% and water as the solvent, which has good fluorescence, printability and resistance. According to the halftone technology, fluorescence quenching of the ZnO QDs by acid, and acid resistance of the organic fluorescent ink, a high-quality anti-counterfeiting method of fluorescent discoloration was proposed. The QDs ink has broad application prospects in the field of anti-counterfeiting green packaging.

Use of reactive dyes of red, blue and yellow colours for exhaustion dyeing of cotton conventional water-based dyeing method and PEG-based solvent-assisted reverse micelle dyeing method was investigated. Calibration curves of both dyeing approaches were established. The calibration results show that red dye can achieve higher absorbance value than yellow and blue dyes and the R-square of the curves can reach a value above 0.99 which indicates the curves are linear in structure and suitable for subsequent measurement. The values of substantivity factor (S), exhaustion factor (E), rate of fixation (R) and fixation factor (F) (SERF) are measured in percentage. The results reveal that using reverse micelle method can achieve higher dye absorption in both exhaustion and fixation processes, resulting in higher final exhaustion of dye in fibre than with the conventional water-based method. Therefore, the reverse micellar dyed samples generally can obtain higher dye absorption, lower reflectance percentage and darker shade in appearance than conventional water-based dyeing.

One limitation in air sampling of airborne microorganisms is their inactivation by forceful impaction and/or dehydration during the collection process. Proper inhalation risk assessments require proof of viability, as non-viable microorganisms cannot cause infectious diseases. In this study, laboratory-generated aerosols of a vegetative bacterium (E. coli) or yeast (S. kudriavzevii) were collected by a laminar-flow water-based condensational “growth tube collector (GTC),” and the GTC’s collection efficiencies were compared with those using an industry standard BioSampler. Collection efficiencies resulting from two types of collection media, phosphate-buffered saline (PBS) and nutrient media (Nutrient Broth, NB, for E. coli, and Yeast Tryptone Glucose Broth, YTGB, for S. kudriavzevii) were also assessed. Both the GTC and the BioSampler performed equally when PBS was used as the collection medium for E. coli, whereas more viable E. coli cells were collected in the GTC than the BioSampler with NB. For S. kudriavzevii, the GTC outperformed the BioSampler using either PBS or YTGB. This is likely because aerosolized E. coli cells can better survive impaction than S. kudriavzevii under the conditions used, and the BioSampler has a much higher collection efficiency for particles in the size range of single-celled E. coli than S. kudriavzevii. Moreover, the GTC had a detection limit one order of magnitude lower for yeast aerosols compared with that of the BioSampler. These results indicate that the GTC is a promising device for sampling viable aerosolized gram-negative bacteria and yeast, as it is less damaging to these types of microorganisms during the collection process.

An ecologically friendly water-based drilling mud (WBM) was designed by using wood wastes (WP: wood powder) in order to substitute the organic polymers which are very expensive and often make the higher cost of the oil well drilling. This present work is dedicated on studying the rheological behavior and main rheological properties of WBM containing the wood powder at different contents and sizes by substitution of usually used polymers. The effect of wood powder on the drilling fluid filtrate was also analyzed. The drilling fluid that was developed has better rheological properties and fluid loss control which are required for a good functioning of oil well drilling. By a total substitution of polymers, the wood powder (300 µm at 850 kg/m3) can be used as a filtrate reducer of mud because the WBM filtrate obtained exhibits a minimum and having requested values for such formation.

This study has investigated the influence of nanoparticles including nanoparticle concentration, size, and type on water-based mud (WBM) properties including rheology, filtration, and lubricity through experimental tests, while the influence of temperature and aging on these properties have been investigated. It has been found that adding SiO2 nanoparticles increase the plastic viscosity and decrease the yield points and gel strengths with the increase of nanoparticle concentration. At fixed 0.5 wt%, the plastic viscosity decreases with the increase of TiO2 nanoparticle size, but the influence of TiO2 nanoparticle size on yield points and gel strengths is not monotonous. In general, adding negative charged SiO2 nanoparticles reduce the yield points and gel strengths, while adding positively charged TiO2, Al2O3, and Fe3O4 nanoparticles increase yield points and gel strengths. Adding lower concentrations (

The current work reports a novel, completely water based approach to prepare the water resistant modified cellulose nanopapers. Lactic acid in aqueous medium was attached on cellulose nanofibers su ...

The properties of thermal conductivity of water based Fe3O4/CuO nanofluid with respect to different parameters such as temperature and weight percent of forming nanoparticles were empirically investigated. The thermal conductivity was measured using hot wire method. According to the results, the thermal conductivity of the Fe3O4 nanofluid in the presence of different concentrations of CuO nanoparticles increases significantly. A linear relationship between increasing the concentrations of CuO nanoparticles and the growth of thermal conductivity of Fe3O4 nanofluid in the temperature range of 25 to 50 °C was observed.

Access to safe drinking water is one of the fundamental human rights and an important component of healthy life. In this paper, the triangular fuzzy numbers approach has been used for recognizing uncertainties in the estimation of health risks proposed by the United States Environmental Protection Agency in Yinchuan city, northwest China. The levels of As, Cd, Cr, Mn, Cu, Zn, Hg, Pb, F, NO3-N, and NH4-N in drinking water were within the permissible limits except for Fe. The results showed that the health risks were primarily attributed by Cr, As, and F in drinking water. When the confidence level was 0.8, the total carcinogenic and noncarcinogenic risks values were less than the acceptable risk levels (10−4 and 1.0) set by the USEPA, respectively. The health risk of drinking water in Yinchuan city is as follows: Nanjiao water source > Beijiao water source > Dongjiao water source. Furthermore, the total noncarcinogenic risks were more sensitive with respect to different confidence levels. The spatial distribution of As and F levels in drinking water sources is urgently needed to be ascertained in drinking water, especially for Nanjiao water source. The health risk assessment model based on the triangular fuzzy numbers approach is effective to quantify uncertainty in risks with less complexity. The findings in this paper will help managers minimize the potential health risks and provide a new insight for solving uncertainties in water management.

Drilling muds are complex formulations of a range of chemicals designed to have specific properties under very specific drilling conditions. Environmentalists including different government and non-government agencies always have a concern regarding the conventional drilling mud system because drilling industry has no choice but to use huge amounts of chemicals as additives. These chemicals are toxic and pose an excessive threat to mankind as well as the environment. The recent priority of any drilling program considers the development of environmentally-friendly drilling fluids so that the ecology is preserved to its maximum level. This article proposes three naturally occurring materials—date seeds, powdered grass, and grass ash as possible additives in the drilling mud system. Sieve analysis and laser particle size analysis are conducted to study the particle size of the three materials. SEM–EDX analysis is performed to know the elemental composition of the proposed additives. Experimental tests on rheology and filtration are conducted at room temperature on the proposed materials to determine the applicability of these natural substitutes as drilling fluid additives. Results show that date seeds, grass, and grass ash can be used as a rheology modifier, and a filtration control agent to formulate the water-based mud system.

Aimed at the problem of poor anti-temperature capability of polymer viscosifier, which cannot meet the needs of ultra-high-temperature water-based drilling fluid, laponite has been studied as an ultra-high-temperature viscosifier. The property of thickening, temperature resistance and salt tolerance of laponite are evaluated. In addition, the viscosifying mechanism of laponite under high temperature has also been analyzed. Experimental results show that laponite has excellent viscosifying ability and thermal stability, and it is able to function at temperature of up to 260 °C. Moreover, the viscosifying effect at high temperature is superior to high-temperature viscosifiers used worldwide. In practice, the reduced rate of apparent viscosity value of bentonite dispersion formulated with 1 wt% laponite is 0% after aging at 260 °C for 16 h, while that of bentonite dispersion with 1 wt% HE300 is 94.7%. Research results indicate that laponite is compatible well with other commonly used additives and has promising application as ultra-high-temperature viscosifier in formulating ultra-high-temperature water-based drilling fluid.

The stresses at the tips of the compressive-sheared cracks were calculated by applying the superposition principle. Then, the principal stresses at the tips of the compressive-shear crack were obtained. According to the Druker-Prager criterion, a fracture criterion for the compressive-shear crack, verified reasonable, was proposed. In addition, considering the influence of water, the above criterion was modified to investigate the influence of water on the stress intensity factors of cracks. The results show that the third principal stress of the main crack surface significantly increases the rock strength when the internal friction angle of the rock is lower than crack inclination angle. However, when the internal friction angle is higher than crack inclination angle, the increase of water pressure dramatically decreases the rock strength. When the internal friction angle is equal to crack inclination angle, the influences of water pressure and the third principal stress on the rock strength are the same. In addition, when crack inclination angle is lower than 30°, the third principal stress greatly influences the rock strength.

In this article, thermal conductivity of ethylene glycol–water-based TiO2 nanofluids has been modeled by artificial neural network. For this purpose, thermal conductivity of nanofluids with volume fractions of 0.2–1 % has been collected in temperatures of 30–70 °C. These data were modeled by artificial neural networks. So two common types of neural networks were used, and the results were compared with each other. One of these networks was multilayer perceptron, and the other one was radial basis approximation. Finally, an experimental relationship was suggested for calculating thermal conductivity of this nanofluid and the results were compared with the results of radial basis neural network. This comparison shows that neural networks are very powerful in modeling the nanofluids experimental data and are able to follow the patterns of these data with a high precision.

A promising strategy for trace analysis of hydrogen peroxide (H2O2) in natural water was established based on solid substrate room temperature phosphorimetry. The use of TiO2/SiO2 composite material as a phosphor for H2O2 detection was investigated. TiO2/SiO2 nanoparticle material was manufactured into a test kit for synchronous multilevel sampling test in the water sample reservoir. The proposed TiO2/SiO2 test kit displayed a wide linear response to H2O2 concentrations ranging from 1.0 × 10(-6) to 1.0 × 10(-1) M with a detection limit of 4.6 × 10(-7) M. When the concentration of other species was 100 times of 1.0 × 10(-4) M H2O2, the proposed test kit exhibited good selectivity toward the coexistence of 20 foreign ions. Satisfactory agreement between the proposed kit and spectrophotometric method was obtained, which demonstrated the possibility of its further development into a promising commercial phosphorescence sensor.

Exercise improves quality of life (QoL). However, little is known concerning the effects of different volumes of strength exercise on QoL. The aims of this study are to: (1) evaluate the effects of water-based strength exercise on QoL of healthy young women and (2) compare the effects of different volumes of water-based strength exercises on QoL of healthy young women. Sixty-six participants were randomly allocated into four groups with different volumes of exercise. The participants performed water-based strength exercises for 20 weeks, two times a week, supervised by trained physiologists. A significant improvement was found in overall QoL (F = 5.96; p = 0.018) and in physical (F = 22.01; p

The VOCs emissions of veneered particleboards coated with nanoparticles modified waterborne polyurethane varnish were investigated in this study. For the improvement of nanoparticles dispersion in waterborne polyurethane varnish, the surface of the nanoparticles was modified with KH550 silane coupling agent. VOCs emissions of coating panels containing various nanoparticles were evaluated with small-scale chamber method. The effect of nano TiO2, montmorillonite (MMT) and the mixture of them in varnish on VOCs degradation of wood-based panels were discussed and compared to the original varnish coating panels without nanoparticles herein. The results showed that treatment of nanoparticles with KH550 improves nanoparticles dispersion, and the modified waterborne polyurethane varnish used for wood-based panels finishing improved VOCs emissions. Various nanoparticles additions in varnish coating panels result in different degradation capacity on VOCs emission. After UV irradiation, the equilibrium concentrations of TVOC emitted from nanoparticles modified varnish coating panels were 21.05–41.57 % lower than of control panel. In addition, aldehydes and ketones compounds were found to exhibit good reduction.

In order to eliminate the disposal issues of toxic chemicals in chemical mechanical planarization, a water-based ultra-polishing experiment with alumina abrasives was investigated for silicon wafer based on Box-behnken theory. It was found that the material removal rate (MRR) was sensitive to pH value, more sensitive to the slurry flow rate, and most sensitive to the oxidizer concentration. Under the optimal conditions of oxidizer concentration (0.44%), slurry flow rate (71.86 mL/min), and natural pH (pH: 7), the highest MRR was derived. Finally, a confuse-understanding of pH on material removal was addressed as well. It was pointed out that the increase in pH leads to the initial decrease in MRR, followed by a rapid increase as pH exceeds 11.

In the past decade, water security has emerged as a new discourse in water governance challenging the more traditional dominant discourse of integrated water resources management (IWRM). This review article applies the ‘ways of knowing’ approach to study the relationship between these two discourses. In doing so, we uncover how IWRM has been narrowly construed as a prescriptive way of knowing water based largely on technical–scientific knowledge, while water security represents a discursive way of knowing water with a greater consideration of human values, ethics and power. We argue that these two ways of knowing are complementary rather than conflicting. As both discourses are pursued at multiple levels, the practical way of knowing will emerge to represent how these concepts interact in a specific policy context.

Copper (Cu) and silver (Ag) nanoparticle are added to water as a base fluid to study the effects of velocity and temperature slip on the flow between converging and diverging channels. A similarity transform has been employed to reduce the nonlinear partial differential equations to a system of nonlinear ordinary differential equations which is then solved by using two analytical schemes variational iteration and variation of parameters methods. For the sake of comparison, a numerical solution using fourth order Runge–Kutta method (RK-4) is also presented. Effects of velocity slip, temperature jump and the other parameters on the flow are discussed and demonstrated graphically. Comparison with already existing results in literature shows the efficiency of the method used.

The lubrication performance of alumina (Al2O3) nanoparticle water-based suspensions was systematically investigated using a ball-on-three-plate testing configuration with alloy steel on stainless steel contact. The size and concentration of Al2O3 nanoparticle were varied to obtain optimal performance. The effects of testing load, sliding speed and contact surface roughness on the lubrication performance of the Al2O3 suspensions were investigated. It was found that 1 to 2 wt.% 30 nm Al2O3 nanoparticle suspensions showed up to 27% friction and 22% wear reduction, in comparison with water glycerol solution. Under different testing conditions, the suspensions also showed noticeably more stable and improved tribological performance. Wear mark analysis revealed that during tribological testing the nanoparticles formed a layer of dynamically balanced tribo-thin film, preventing the direct contact between asperities of alloy steel ball and stainless steel plate. The nanoparticles were also believed to fill up the trenches of the plate surface through mending effect and carry the wear debris induced in running-in period to avoid abrasive wear.

High-strength antifriction polymeric carbon plastics of UGET and FUT types and their modifications UGET-TN, FUT-B, UGET-MF, and FUT-MF as well as a new heat-resistant antifriction carbon plastic of UPFS type were developed for oil and gas and power machine making. These materials are superior to traditional polymeric antifriction materials in strength and wear resistance.

The design and operating principle of a two-phase flowmeter for mixtures of oil and stratal water based on a restriction and gamma densitometer are presented. Results of tests of the flowmeter on the Multiphase Test Facility of TUV SUD NEL Ltd (Glasgow, Great Britain) are presented. The operating features of the restriction are noted and the compliance of the obtained characteristics of the flowmeter with State Standard requirements is evaluated.

A laboratory experiment was designed to collect the spectral reflectance of water containing suspended particulate matter (SPM) in terms of its concentration. By performing surface-fitting analysis, an empirical relationship among the wavelength, reflectance, and concentration of SPM in water was obtained. The results showed that a linear effect of the spectral wavelength on spectral reflectance with increasing concentration of SPM in water, and the relationship between the reflectance and concentration of SPM in water is quadratic. Hyperspectral remote sensing is expected to play an important role in estimating the concentration of SPM in water.

Till now, water based lubricants, especially aqueous solutions, have not been employed in the elastohydrodynamic lubrication (EHL) due to their poor film forming capability or low wear resistance. In this paper, we proposed a method to develop water based lubricant: employing polyalkylene glycol solution as base stock to improve EHL film forming capability and using organic phosphate ester (DPZ) as anti-wear additive to improve wear resistance property. The lubricating properties of the mixed solutions, including load carrying capability, wear resistance property, friction reduction property, EHL film forming behavior, were investigated. The experimental results indicate that the mixed solution presents excellent lubricating properties, which make it a promising candidate in developing water based lubricants.

A novel water-based slow injection ultrasound-assisted emulsification microextraction (SI-USAEME) method followed by ultra-high performance liquid chromatography-tandem mass spectrometry analysis was developed for the rapid pretreatment and determination of deoxynivalenol (DON) and its metabolite, de-epoxy-deoxynivalenol (DOM-1), in maize and pork samples. After optimization, the method recoveries for DON and DOM-1 ranged from 73 to 85 % with intraday and interday variations less than 9.4 and 9.2 %, respectively. The limits of detection for DON were 4.2 μg kg(-1) in maize and 6.2 and 5.9 μg kg(-1) for DON and DOM-1, respectively, in pork. In addition, an immunoaffinity column (IAC) was prepared. A study comparing the IAC cleanup method, the solid-phase extraction (SPE) cleanup method, and the proposed SI-USAEME method was presented. The water-based SI-USAEME method could become a simple, low-cost alternative to the conventional IAC and SPE method. The method was successfully applied to the analysis of commercial maize and pork products.

To analyze mining hydrogeological conditions and determine the sources of mine water, a hydrothermal deposit of China is taken as an example in this paper. On the basis of detailed geological and hydrogeological analysis of conditions in the mining area, the hydrogeological characteristics of a fault system of F1 in this mine are determined using a pumping test method and isotope technology. Hydraulic connections between the Majiagou group and Xiaoxian group are given a detailed illustration. The results show that the F1 group of faults is channeling water. Under significant drawdown, fissure water and Lower Pleistocene porous confined water are indirect sources of mine water, but water supply in unit time is limited. According to the analysis results, water will enter the pit during mining at a rate of 12,680 m3/d. In contrast, if the transmission performance of the F1 group of faults is ignored, the porous confined water will not enter the pit, and the mine water inflow will be 9700 m3/d. This is a decrease of 2980 m3/d, accounting for 30.72 % of mine water inflow. Therefore, the effect of water sources on mine water inflow cannot be ignored.

The research on the effects of aquatic exercise is a field that has grown rapidly in the last decade. The majority of the available literature is focused on the benefits of water-based exercise programs for people with rheumatologic disease and back pain; however, there is a lack of evidence reporting the effects of exercise performed in an aquatic medium for healthy elderly adults. The purpose of this study was to critically review the existing evidence of a potential relationship between water-based exercise and improvement of physical fitness in healthy elderly subjects. A systematic database search for manuscripts and a quality control were performed. A system of rating was defined. Aerobic, muscular strength, flexibility and body composition outcomes were then extracted. Nine studies were analyzed after the screening for eligibility: five randomized controlled trials (RCT), three randomized uncontrolled trials (UT) and one controlled trial (CT). Four RCT and two randomized UT were classified as high quality studies. One RCT, one randomized UT and one CT were considered low quality studies. Strong evidence supports the use of water-based exercise for the improvement of aerobic capacity and strength. Moderate evidence highlights the benefits on flexibility, and inconclusive evidence was found supporting the modification of body composition.

The front photopyroelectric configuration was applied to measure the thermal effusivity of some composite materials, inserted as backing layers in the detection cell. The technique is based on the scanning procedure of the coupling fluid’s thickness (TWRC method). Two particular composite materials were selected for investigation: (i) a liquid one: water based nanofluids with gold nanoparticles and (ii) a solid one: urea—fumaric acid (1:1) cocrystal. The thermal effusivity was found independent on the size and concentration of gold particles. Concerning the urea—fumaric acid cocrystal, the thermal effusivity value of the compound is different from the pure starting materials, indicating the formation of the compound.

The performance of automatic fire extinguishers (AFE) was tested using a novel nozzle distribution test in relation to a point of visual approach. The visual nozzle distribution data was obtained from the mapping of the amount of the collected fire extinguishing agent to each position and the gradient was given in accordance with the visually collected amount. The results showed that the effective discharge time was determined by the nozzle structure and its size. The visual nozzle distribution test (VNDT) provided relevant information regarding the performance efficiency of AFE, including the nozzle coverage area, the effective amount of the fire extinguishing agent and the distribution uniformity of fire extinguishing agents, and calculations for the proper amount of a fire extinguishing agent to extinguish a fire. Consequently, the results indicate the VNDT is an excellent method for analyzing the performance efficiency of AFE.

In the paint processes of modern car plants the paint to be applied on the car bodies change after every few numbers. In order to avoid intermixtures of different lacquers the application systems has to be cleaned before every change by means of a rinsing liquid. Water based lacquers require water based cleaning agents. For these rinsing waters a new recycling process based on an evaporation process, a fractionated condensation and an after treatment of the condensates is described. The compatibility of the recycled system for lacquers is investigated. After a test with ten recycling loops no accumulation of harmful substances occurs. In comparison to original agents the recycled rinsing liquids show comparable or better cleaning abilities. The comparison of the energy consumption and the disposal of CO2 and of volatile organic compounds between the application of fresh rinsing liquid with disposal after usage and recycled rinsing liquid show major advantages of the recycling process.

In this paper, a comparative study of CO2 and water-based brine secondary cooling systems for refrigeration applications is presented. CO2 secondary systems are simple and could prove to be attractive for high temperature (HT) and medium temperature (MT) in industrial and commercial refrigeration applications regardless of climate. Calculations show that CO2 secondary systems give a possibility of energy savings in the range of 10–20% for HT systems and more than 20–30% for MT systems. The design and particular challenges of CO2 systems are discussed. The analysis is illustrated by case studies. Further possibilities to optimized secondary CO2 systems by modulating pressure or applying frequency converters are discussed. The use of secondary CO2 systems in commercial refrigeration installations (supermarket systems) is briefly discussed.