Suitable Amount Of Water Research Articles

Effect of water to cement ratio on acoustic impedance, microstructure, and piezoelectric properties of 0-3 barium zirconate titanate-Portland cement composite with epoxy resin addition

Smart 0-3 barium zirconate titanate (BZT)-Portland cement (PC) composites with 50 vol.% BZT and 7 vol.% epoxy resin were developed for concrete structural health monitoring application. Water to cement (w/c) ratio was used at 0.05, 0.10 and 0.15 to determine optimum mixing by pressing and curing method and properties of the composites. Both ρc and Zc values increased with increasing w/c ratio up to 0.10 but a reduction in the ρc and Zc values can be observed at w/c = 0.15. The d33 and g33 values of the composite were found to increase with the w/c ratio especially when used at 0.10 where the d33 value is 16.5 pC/N, g33 value is 13.1 × 10−3 V·m/N. The highest kt value (17.21 %) can be observed at w/c = 0.10. Therefore, using a suitable amount of water in the composites can improve physical properties and piezoelectric properties when epoxy resin was added as a third phase.

Strong Evidence of the Role of H2O in Affecting Methanol Selectivity from CO2 Hydrogenation over Cu-ZnO-ZrO2

Summary CO2 hydrogenation to methanol with renewable H2 is an ideal process for coupling reduction of greenhouse gas and development of sustainable methanol economy, and Cu-ZnO-ZrO2 is regarded as a promising catalyst for this process. Identification of the key descriptors that control the catalytic activity and selectivity is one of the most important issues for this reaction. Here, we identify the role of water in the hydrogenation of CO2 to methanol, which strongly affects the selectivity and yield of methanol. Our results reveal that methanol is generated via the hydrolysis of methoxy formed by the hydrogenation of formate, and the desorbed water vapor facilitates the hydrolysis of methoxy. A suitable amount of water in the feed can promote the formation of methanol. The enhancement on the water vapor diffusion in catalysts by structural and/or surface modification offers a new strategy for tuning the selectivity and yield of methanol.

Pretreatment of agricultural residues by supercritical CO2 at 50–80 °C to enhance enzymatic hydrolysis

Abstract Various agricultural crop residues including corn stover, corn cob, and sorghum stalk with a moisture content of 75 wt% were subjected to a long pretreatment (12–60 h) with supercritical CO2 (scCO2), at low temperature (50–80 °C) and a pressure of 17.5–25.0 MPa. The sugar yields from the enzymatic hydrolysis (EH) of the pretreated samples were as much as three- to fourfold greater than those afforded by the raw materials. However, when pretreatment was conducted within a short time (e.g. 0.5 h), as previously reported in the literature, only a slight increase in the EH sugar yields was observed. The proposed scCO2 pretreatment mechanism demonstrated the role of moisture in the system. Wetting, softening, and swelling were observed to mainly affect the lignocellulose when a suitable amount of water was added. Finally, the samples were analysed by X-ray diffraction and scanning electron microscopy, before and after pretreatment, to investigate the changes in the microscopic structure of the biomass.

Drinking water in traditional Persian medicine: Do's and don'ts.

Water is the main component of our body and its balance is vital for maintaining normal physiology. Accordingly, adequate fluid intake in the daily diet is very important for a healthy life. Nevertheless, there is a controversy about what the suitable amount of water that we need to drink is. In this paper, we aimed to discuss this important issue based on the doctrine of traditional Persian medicine (TPM) and our clinical experience in a practical manner.

Engineering of lipase-catalyzed transesterification reaction media using water and diethylamine

The objective of presented study was to maximize yields of 2-methylbutyl esters, derived by transesterification reactions mediated by sn-1,3-specific lipases, through engineering of reaction medium. Effects of water and diethylamine (DEA) concentrations on the efficiency of plant oils 2-methylbutanolysis, catalyzed by either mycelium-bound Mucor circinelloides lipase (powder) or commercial immobilized lipase Lipozyme TL IM, were determined. Water content monitoring in reaction mixtures enabled to optimize the initial water content in terms of preventing the dehydration of enzyme’s microenvironment and increasing 2-methylbutyl esters yields. These yields were found to be increased by addition of either suitable amounts of water (0.5–1.5%) or diethylamine (10–30 mM) to the mixture of substrates. The presented results suggest that at low concentrations, diethylamine molecules contribute to retaining water in the microenvironment of enzyme that gives rise to increased transesterification yields and significantly reduced amounts of residual mono- and 1,2-diacyl-glycerols.

Development of an Automatic Plant Monitoring System

Automated system operates with less human interaction which reduces job overheads. This paper represents an automated plant monitoring system which could be applicable for practical plantation field in Malaysia to boost up the agricultural productions. The monitoring system, which is presented in this paper, uses three sensors to measure humidity, temperature, and moisture of the surroundings of the test plant and provides the most suitable amount of water to plant depending on the coefficient generated from the sensors’ data. Arduino Global System for Mobile Communication (GSM) Shield is also integrated with the system to monitor the process using mobile phone. Considering the reduction of environmental pollution, solar power system is used to power-up the designed monitoring system. Low cost and good results of practical experimentations present that the system is viable to implement in large scale plant monitoring and irrigation.

Water-assisted and surfactant-free synthesis of cobalt ferrite nanospheres via solvothermal method

With ethylene glycol as the solvent, monodispersed cobalt ferrite nanospheres were prepared via a solvothermal method assisted by water. The samples were mainly characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. The size of as-prepared products ranges from 10 nm to 200 nm. Size distribution and chemical composition were controlled by the amount of water and pH value in the reaction system. More important, suitable amount of water can avoid the use of surfactant.

Preparation of amphiphilic nano-sized NaA/glass films and powders using layer-by-layer in-situ sol–gel method

Nano-sized NaA/glass films were prepared by a layer-by-layer in-situ sol–gel method combined with the steam-assisted conversion technique. Consequently, nano-sized zeolite NaA powders were obtained by scraping the films and treating the resultant powders with a 0.6% acetic acid solution. The films and the powders were characterized by XRD, FT-IR, SEM, TEM, and AFM, and their hydrophilicity and antimicrobial activity after Ag+-exchange were examined. The preparation conditions such as the reaction time and the amount of water prefilled in the autoclave were examined. The NaA crystals on the films are about 50–100 nm in size and they are aggregated together. Their particle sizes can be further reduced to 40–80 nm and they can be changed from aggregated to highly dispersed particles after treated in the acid solution. The amount of water during the synthesis is quite important for successful synthesis of well-crystallized nano-sized zeolite NaA on the glass. And dispersed 40–50 nm zeolite NaA particles can be obtained when suitable amount of water is used. The nano-sized NaA/glass film exhibits superhydrophilicity and oleophilicity. After ion-exchange with Ag+, the NaA/glass film shows high antimicrobial activity, better than the nano-sized NaA powders and other NaA films or coatings reported in literature.

Effect of Alkali and Water Content on Setting Time and Strength of Fly Ash Based Geopolymer

The current work presents the effect of alkali concentration and water content on fly ash based geopolymer material. In this paper geopolymer material was prepared where Si/Al ratio (1.85: 1) is fixed and solid to water ratio (S/W) and NaOH concentration (4M, 8M, 12M) were varied. All samples were tested to establish the roles of water and alkali on the setting time and strength. At low solid to water ratio, (S/W= 3:1), the water quantity is high and the hardening of gel phase take more time. However, as water content is reduced from S/W 3:1 to 4:1 ratio, the setting point decreased significantly and only small change in setting time is observed when S/W shifted from 4:1 to 5:1. Sample prepared with 8M of NaOH showed the highest compressive strength. In this regards, Fourier transform infrared spectroscopy (FTIR) results support this observation where broad band (asymmetric strectching band) become sharper and shift towards lower wavenumber (1082.36 cm-1 to 985.16 cm-1). This finding shows that, to obtain required processing time at desired mechanical strength (20-30 Mpa) for a specific application of geopolymer, the suitable amount of water must be established.

Liquid Sugar Extraction from Date Palm (Phoenix dactylifera L.) Fruits

In date syrup manufacturing, date fruits (Phoenix dactylifera L.) are mixed with a suitable amount of water with heating at a temperature greater than 70°C for about 1 h. These conditions are not satisfactory for extraction greater amount of liquid sugar (date syrup). In addition, overheating for an extended period could damage nutritious materials and changes product’s color. In this study, pectinase/cellulase enzymes and sonication processes were used to achieve maximum syrup extraction from a date variety (Reziz) compared with classical method. The following variables were examined: fruit/water ratio, mixture of enzymes percent and ultrasonic power. Enzymes and Ultrasound were applied for improving the quantity and quality of extracted syrup. Date extract was filtered with filter system (Novox 200, filtrox) which could result entirely a clear syrup and then concentrated by a rotary evaporator until about 75% total solids to produce higher quality syrup. Physicochemical properties of each collected sample during process were evaluated. Results showed that sonication power 25% at ratio 1/3 D/W could lead to a higher extraction of RSS (Recovery of Soluble Solids) (74.30%) in a shorter time with a better physicochemical quality of syrup in comparison to mixture of enzymes 1.0% (66.70%) and classical methods of extraction (58.45%). Data indicated the possibility of employing ultrasound (25%) or enzymes processes (pectinase/ cellulase 0.1%) for producing greater syrup amount highly desirable for use in food product development.

Rhyolite-MELTS: a Modified Calibration of MELTS Optimized for Silica-rich, Fluid-bearing Magmatic Systems

Silicic magma systems are of great scientific interest and societal importance owing to their role in the evolution of the crust and the hazards posed by volcanic eruptions. MELTS is a powerful and widely used tool to study the evolution of magmatic systems over a wide spectrum of compositions and conditions. However, the current calibration of MELTS fails to correctly predict the position of the quartz þ feldspar saturation surface in temperature, pressure and composition space, making it unsuitable to study silicic systems. We create a modified calibration of MELTS optimized for silicic systems, dubbed rhyolite-MELTS, using early erupted Bishop pumice as a reference. Small adjustments to the calorimetrically determined enthalpy of formation of quartz and of the potassium end-member of alkali feldspar in the MELTS calibration lead to much improved predictions of the quartz þ feldspar saturation surface as a function of pressure. Application of rhyolite-MELTS to the Highland Range Volcanic Sequence (Nevada), the Peach Spring Tuff (Arizona^Nevada^California), and the late-erupted Bishop Tuff (California), using compositions that vary from trachydacite to high-silica rhyolite, shows that the calibration is appropriate for a variety of fluid-bearing silicic systems. Some key observations include the following. (1) The simulated evolutionary paths are consistent with petrographic observations and glass compositions; further work is needed to compare predicted and observed mineral compositions. (2) The nearly invariant nature of silicic magmas is well captured by rhyolite-MELTS; unusual behavior is observed after extensive pseudo-invariant crystallization, suggesting that the new calibration works best for relatively small (i.e.550 wt %) crystallization intervals, comparable with what is observed in volcanic rocks. (3) Our success with rhyolite-MELTS shows that water-bearing systems in which hydrous phases do not play a critical role can be appropriately handled; simulations are sensitive to initial water concentration, and although only a pure-H2O fluid is modeled, suitable amounts of water can be added or subtracted to mimic the effect of CO2 in fluid solubility. Our continuing work on natural systems shows that rhyolite-MELTS is very useful in constraining crystallization conditions, and is particularly well suited to explore the eruptive potential of silicic magmas. We show that constraints placed by rhyoliteMELTS simulations using late-erupted Bishop Tuff whole-rock and melt inclusion compositions are inconsistent with a vertically stratified magma body.

Study on Influencing Factors of Flow-Ability of Cement Asphalt Mortar

Flow-ability of CA mortar is characterized by fluidity, and the effects of the CA mortar fluidity according to water, time, and feeding sequence are studied. Studies have shown that the amount of the used of water affects the fluidity most, in which the suitable amount of water is between 0.23 and 0.28. With the time delay, the flow-ability of CA mortar is reduced. When mixed with SBR latex, the process of decay of the flow-ability is significantly reduced. Feeding sequence has great effect on fresh mixed CA mortar. In the mixing process, to avoid asphalt emulsion and cement dry material in direct contact, the speed of demulsification is reduced, which can effectively increase the flow-ability of CA mortar.

The direct effect of ultrasound on the extraction of date syrup and its micro-organisms

In the date syrup industry, date fruits are mixed with a suitable amount of water at a temperature greater than 50 °C for about 1 h. This condition is not sufficient for killing the micro-organisms present in the fruit. In addition, Overheating for a long time can damages nutritious materials and also changes the final product's color. Ultrasound was applied for improving the quantity and quality of the extraction, and also to overcome the health problem. In this research, the following variables were examined: date fruit/water ratio, ultrasonic intensity and temperature. The results showed that sonication under the proper conditions can lead to a higher extraction in a shorter time with a better physical quality of the product. Most importantly, the sonication significantly decreased the microbial count in comparison to the classical method. This study also confirmed the presence of anti-microbial substances in date fruit, and that ultrasonic waves can accelerate their effects.

Molecular configurations and orientations of hydrazine between structural layers of kaolinite

Hydrazine is one of the most commonly used entraining agents to penetrate kaolinite, yet the mechanism of intercalation of kaolinite by hydrazine is still in debate. The objectives of this study are to investigate the possible molecular configurations and orientations of hydrazine in the interlayer of kaolinite and the configuration changes induced by water molecules. Water molecules increased the intercalation rate and caused the expansion of the intercalation complex from 0.96 to 1.03 nm. The kinetic effect was likely the result of breaking the self-associations of hydrazine molecules and releasing more “free” hydrazine molecules for the intercalation. H-bonding caused large red shifts of the inner surface OH stretching bands from 3695 to 3626 cm −1 in the 0.96-nm kaolinite hydrazine intercalation (KHI) complex and to 3570 and 3463 cm −1 in the 1.03-nm KHI complex. The NH stretching bands of the hydrazine molecules in the KHI complexes became sharper and blue-shifted more than 20 cm −1 compared with the free liquids. The symmetric NH vibrations at 3365 and 3310 cm −1, and the NN vibration at 1092 cm −1 became infrared inactive in the 0.96-nm KHI complex. The frequency of the SiO bands of the kaolinite in the 1.03-nm KHI complex was slightly lower than in the 0.96-nm KHI complex (5 cm −1 shift). These IR band changes implied that hydrazine molecules have different configurations in the complexes: hydrazine molecules had an eclipsed form in the interlayer of the 0.96-nm KHI complex. The eclipsed configuration has a dipole moment of 3.31 D, which is higher than the gauche form (1.83–1.90 D). The molecule was oriented with the NN bond parallel or nearly parallel to the (001) surface of the mineral and the four H atoms of each hydrazine molecule reacted with the basal siloxane surface. When a suitable amount of water was present, it promoted the configuration change of the hydrazine molecules from the eclipsed form to the common gauche form. This gauche form was stabilized by transforming to a more polarized NH 3NH tautomer structure (5.4 D). To promote an optimal interaction between hydrazine and the mineral surface, the NN bond of the hydrazine was tilted about 30° from the (001) plane and caused the intercalation complex to expand from 0.96 to 1.03 nm. The eclipsed form and the tautomer were stabilized by the asymmetric interlayer environment of kaolinite. The two proposed models and reaction mechanisms match the high dipole moment requirement as found for other entraining agents. Further investigation is needed to confirm the exact configuration of hydrazine molecules and whether or not the tautomer exists.

Determination of the optimal amount of water in liquid-fill masses for hard gelatin capsules by means of texture analysis and experimental design

The aim of this study is to use texture analysis as a non-destructive test for hard gelatin capsules filled with liquid formulations to investigate mechanical changes upon storage. A suitable amount of water in the formulations is determined to obtain the best possible compatibility with the gelatin shell. This quantity of water to be added to a formulation is called the balanced amount of water (BAW). Texture profiling was conducted on capsules filled with hydrophilic polymer mixtures and with formulations based on amphiphilic masses with high HLB value. The first model mixture consisted of polyethylene glycol 400 and polyvinylpyrrolidone K17 with water and the second type consisted of caprylocaproyl macrogol glycerides (Labrasol®) with colloidal silica (Aerosil® 200) and water. The liquid-fill capsules were investigated by measuring changes on mass and stiffness after storage under confined conditions in aluminium foils. Capsule stiffness was investigated also as a parameter in a response surface analysis to identify the BAW. Polyvinylpyrrolidone did not show a great influence on the BAW in the range of 10–12% (w/w) for the first model mixture. Capsules with the less hydrophilic Labrasol® formulations, however, kept their initial stiffness after storage best with only half of that amount, i.e. 5–6% (w/w) of water in the compositions. From this study it can be concluded that texture profiling in the framework of an experimental design helps to find hydrophilic or amphiphilic formulations that are compatible with gelatin capsules. Short-term stability tests are meaningful if capsule embrittlement or softening is due to water equilibration or another migration process that takes place rapidly. Long-term stability tests will always be needed for a final statement of compatibility between a formulation and hard gelatin capsules.

Enzymatic synthesis of low‐calorie structured lipids in a solvent‐free system

AbstractFor the synthesis of low‐calorie structured lipids (LCSL), transesterification between triacetin and stearic acid using immobilized lipase in a solvent‐free system was investigated. Stearic acid, a long‐chain saturated fatty acid, was incorporated mainly into the sn‐1 and/or sn‐3 positions of triacetin by lipase‐catalyzed reaction. Three types of reactor systems (open, closed, and vacuum) were studied for the production of LCSL. The effects of various reaction variables such as water activity of substrates and lipase, molar ratio of substrates, stirring speed and reaction temperature were investigated. In the vacuum reactor system, a certain amount of water was added periodically to maintain the optimal water content of the reaction system. When a suitable amount of water (0.65 wt% of substrates) was added at every 1 h into the vacuum reactor system, more than 88% LCSL was obtained within 4 h using Chirazyme® L‐2.

Improvement (5-fold) of enantioselectivity for lipase-catalyzed esterification of a bulky substrate at 57�c in organic solvent

A reaction temperature at 57° C produced an improvement of lipase's enantioselectivity for an esterification of a bulky substrate, such as 2-(2-methyl- or 4-tert-butyl-phenoxy) propionic acid, in organic solvent with a suitable amount of water added, although the poor enantioselectivity was observed for its bulky substrate under ordinary reaction conditions.

Natural removal of added N-nutrients, reactive phosphorus, crude oil, and heavy metals from the water phase in a simulated water/sediment system

Water/sediment simulation systems were constructed by using an aquarium (0.45 × 0.29 × 0.35 m 3), filled with suitable amounts of water and sediment collected from three selected locations: Lan Hua Shan (LHS), Tai Hu (TH), and Loong Yu Tao (LYT) of the Zhujiang (Pearl River) Estuary of China in November 1992 at low-tide period. The salinities of the water samples collected from LHS, TH, and LYT were found to be 0.2, 4.6, and 16.2 g L −1, respectively. Known amounts of ammonium, nitrate, nitrite, reactive phosphorus, crude oil, arsenate (III), cadmium (II), chromium (III), copper (II), and zinc (II) were added as pollutants into each of the water/sediment simulation systems. The rates of the natural removal of each added pollutant in all water/sediment simulation systems were studied by monitoring their concentrations at various intervals in the investigation period. Except for Cr (III) and reactive phosphorus in the water/sediment systems of the LHS, TH, and LYT sites, and nitrate in the TH and LYT sites, the concentrations of the added pollutants in the water phase of the studied systems under a flow-condition simulation were reduced to 8% or less of the corresponding added amount on or before the 12th day by natural processes. The rate of self-purification and the estimated assimulative capacity of each added pollutant in all water/sediment simulation systems is discussed.

Effect of temperature on lipase-catalyzed esterification in organic solvent

For the esterification of 2-(4-ethylphenoxy)propionic acid catalyzed by lipase MY (Candida rugosa) in isopropyl ether containing a suitable amount of water, the enantioselectivity for the reaction has become higher as the reaction temperature increasing. In contrast, the reverse trend of the temperature effect has been observed for lipase AY (Candida rugosa). A model for these temperature dependence has been proposed.

Esterification Activity of Immobilized Lipase Entrapped in Thermal-phase Transition Gel.

Lipase was entrapped in poly-N-isopropylacrylamide gel beads which underwent thermally induced phase transition. Catalytic activity of the immobilized enzyme in the gel beads (IEG) was studied for esterification in organic medium and, for comparison, hydrolysis in aqueous medium. The activity of IEG changed significantly before and after the phase transition. The esterification activity leapt up with the phase transition at which the gel altered from swollen to shrunken state, whereas the hydrolysis activity fell. The esterification activity change was thought to be caused by change in the amount of environmental water in and around the IEG. To clarify the effect of environmental water on the esterification activity, four IEGs, different in their state and amount of environmental water, were employed for the esterification, and their activities were compared. IEG was most active when it shrunk and was surrounded with a suitable amount of water.