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A reduction reaction of 5-hydroxymethylfurfural to 2,5-dimethylfuran (2,5-DMF) has been previously performed in an organic solvent under high-temperature conditions. For the relaxation of such reaction conditions, conventional palladium on carbon (Pd/C) was combined with vesicles composed of phospholipids or surfactants. Pd/C combined with 1,2-dioleoyl-sn-glycero-3-phosphocholine indicated a yield (25%) at 60 °C compared with Pd/C (17%). Vesicles at the liquid crystalline phase were advantageous for the reduction reaction of HMF. The yield of 2,5-DMF catalyzed by Pd/C combined with the vesicles depended on the lipid composition of the vesicles. It was clarified that the yield of 2,5-DMF could be controlled by the hydration property of the vesicles. Compared with conventional 2,5-DMF synthesis in an organic solvent, the use of vesicles made it possible to reduce the burden of using organic solvents in high-temperature conditions, although limitedly. [ABSTRACT FROM AUTHOR]

Based on the analytical and experimental researches, the factors that influence the formation of the technological properties of Pleurotus ostreatus mushrooms have been determined. It was found that the technological properties of this type of mushroom depend on the conditions and timing of cultivation and storage, as well as on the structure of individual parts of the fruiting body and on the chemical composition, namely, the content of proteins, fiber and water, including bound water. [ABSTRACT FROM AUTHOR]

Permeability and bound water saturation (Swb) are key parameters reflecting the petrophysical properties of porous rocks. Nuclear magnetic resonance (NMR) has proved to be effective in investigating the properties of porous media. However, estimating Swb and the permeability in tight sandstone reservoirs based on conventional NMR methods, which requires the inversion of NMR echo data to obtain the transverse relaxation time (T2) distribution, proves to be a challenging task. In this study, a method is proposed to estimate Swb and the permeability in tight sandstone reservoirs based on the direct analysis of NMR echo data, thus avoiding the inversion process. A total of 20 tight sandstone samples from the Ordos Basin in China was taken for laboratory NMR measurements. The kernel function of the echo data was used to characterize the ratio distribution of bound water volume to pore volume for different pore sizes. Following this, an echo data calibration method was applied to estimate Swb without the inversion of the T2 distribution, and the window method was used to reduce the impact of noise in the echo data. Furthermore, models for estimating permeability were proposed based on the determined windows of the NMR echo data in the Swb estimation. The reliability of the proposed method for estimating Swb and permeability was verified by comparing the estimated and experimental results. Our study provides an efficient method for the estimation of petrophysical parameters in porous rocks based on the direct analysis of NMR echo data. [ABSTRACT FROM AUTHOR]

Graphical abstract Aggregation of PMS and fumed silica nanoparticles is stronger than that in PMS alone. Abstract Disperse polymethylsiloxane (PMS) alone and in a mixture with highly disperse nanosilica A-300 was studied as a dry powder and a hydrogel located in various dispersion media (air, chloroform alone and with addition of trifluoroacetic acid) using low-temperature 1H NMR spectroscopy, cryoporometry, thermogravimetry, nitrogen adsorption, microscopy, infrared spectroscopy, and quantum chemistry. The powders of dried PMS and PMS/A-300 can be easily rehydrated upon strong stirring with added water. The slurry properties depend on mechanical treatment features due to stronger compaction of the secondary structures with increasing mechanical loading. The organization of bound water (at a constant hydration degree h = 1 g/g) depends strongly on the dispersion media (because chloroform can displace water from narrow interparticle voids into broader ones or into pores inaccessible for larger CDCl 3 molecules) and mechanical loading reorganizing aggregates of PMS and A-300 nanoparticles (<1 μm in size) and agglomerates (>1 μm) of aggregates. The PMS/nanosilica blends could be of interest from a practical point of view due to additional control of the textural and structural characteristics determining efficiency of sorbents with respect to low- and high-molecular weight compounds depending on the dispersion media that is of importance, e.g., for medical applications. [ABSTRACT FROM AUTHOR]

Background: Hyaluronic acid (HA) has been considered the gold standard ingredient for improving skin hydration and combating age‐related effects, however it is an inefficient polymer with inconsistent results partially due to its poor skin penetration, surface deposition, and rapid degradation. Herein we report the synthesis and in vitro characterization of a newly developed, topical super‐humectant with the goal of attracting and binding water molecules more efficiently than traditional, cosmetic‐grade forms of HA. Methods: A modified interpenetrating polymer network (IPN) was developed using three polymers into a three‐dimensional formation (3D3P) for entrapping HA and water. This 3D3P‐IPN functions as a super‐humectant, attracting and binding water molecules more efficiently than the traditional cosmetic‐grade forms of HA. We compare 3D3P‐IPN serum samples to a traditional commercial benchmark product of similar ingredients using microscopic analysis, rheology, Karl Fischer (KF) titration, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and dynamic vapor sorption (DVS) techniques. Results: The 3D3P‐IPN samples appeared to bind water tighter than the benchmark sample as evidenced by maximum endpoints of endotherms occurring at significantly higher temperatures. The DVS results further confirm this speculation as the 3D3P‐IPN samples lost approximately 10% less water up to 35% RH than the benchmark. The 3D3P‐IPN samples also absorbed more water as the humidity level increased,demonstrating superior humectant properties. KF titration indicated that all three samples had similar water concentrations; however, TGA results demonstrated that the benchmark (a viscous, humectant‐rich hydrating masque) did not have much bound water. Conclusion: Through the synthesis of a 3D3P‐IPN using simplified methods, we were able to increase the water‐binding and HA‐delivery capabilities of a thin serum. This 3D3P‐IPN serum has potential to deliver more hydration to the skin's surface compared to traditional HA formulations. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of the moisture loss, diameter, and wood density on the appearance of surface cracks and end splits in Eucalyptus urophylla logs. The drying and emergence of defects were evaluated in 108 logs with diameters ranging from 60 mm to 150 mm from the initial moisture content to the equilibrium moisture content. The defects were measured during this time. Smaller diameter logs dried faster than larger diameter logs and took less time to reach the fiber saturation point. Surface cracks tended to develop during the loss of bound water. End splits developed during free water loss and continued to appear during bound water loss. Smaller diameters presented higher percentages of surface cracks compared with larger diameters, while larger diameters had a tendency for higher percentages of end splits compared with smaller diameters. The density did not influence the total emergence of end splits, but it did influence the total emergence of surface cracks, indicating a possibility for the selection of genetic material with lower tendency for cracking. Overall, the results reinforce the need to control drying at its beginning in order to decrease the risk of defects. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Above the threshold level of hydration (Δm/m 0 ≈ 0.38), the cooperative bound water freezing is detected. • Below the threshold hydration level, the transfer of loosely to tightly bound water is detected. • Two-hour incubation DSC experiment (at t = −20 °C), suggests the water molecules diffusion to ice crystallites. Abstract The studies of low-temperature immobilization of bound water in Antarctic lichenized fungus Turgidosculum complicatulum were performed using 1H NMR and DSC over a wide range of thallus hydration. 1H NMR free induction decays were decomposed into a solid component well described by the Gaussian function and two exponentially decaying components coming from a tightly bound water and from a loosely bound water fraction. 1H NMR spectra revealed one averaged mobile proton signal component. 1H NMR measurements recorded in time and in frequency domain suggest the non-cooperative bound water immobilization in T. complicatulum thallus. The threshold of the hydration level estimated by 1H NMR analysis at which the cooperative bound water freezing was detected was Δm/m 0 ≈ 0.39, whereas for DSC analysis was equal to Δm/m 0 = 0.375. Main ice melting estimated from DSC measurements for zero hydration level of the sample starts at t m = –(19.29 ± 1.19)°C. However, DSC melting peak shows a composed form being a superposition of the main narrow peak (presumably melting of mycobiont areas) and a broad low-temperature shoulder (presumably melting of isolated photobiont cells). DSC traces recorded after two-hour incubation of T. complicatulum thallus at –20 °C suggest much lower threshold level of hydration at which the ice formation occurs (Δm/m 0 = 0.0842). Presumably it is a result of diffusion induced migration of separated water molecules to ice microcrystallites already present in thallus, but still beyond the calorimeter resolution. [ABSTRACT FROM AUTHOR]

Knowledge of the dynamic changes in the water absorption process of heat-treated wood is important for providing a scientific basis for the reasonable application of heat-treated wood, especially for outdoor applications. Nuclear magnetic resonance (NMR) techniques provide detailed information about the moisture components and moisture transport processes in wood, which are not available with other methods. In this work, water absorption of untreated and heat treated Chinese fir (Cunninghamia lanceolata [Lamb.] Hook.) heartwood was investigated using various NMR methods. The heat treatment temperatures were varied between 160 °C and 220 °C. According to the spin-spin relaxation time (T2), there were two components of water in the samples heat-treated at 160 °C and 180 °C as well as the untreated sample, while three components of water were found in the samples heat-treated at 200 °C and 220 °C, and the mass of each component was calculated by the integral peak areas of the T2 curve. The amount of bound water and free water in heat-treated samples were less compared to the untreated ones, and the water absorption decreased correspondingly, due to the increasing heat-treated temperature. The results obtained by one dimensional frequency coding indicated that the heat treatment made wood difficult to be accessed by moisture. Besides, NMR images revealed that the free water absorption in latewood was faster than in earlywood, but earlywood could absorb more water than latewood. [ABSTRACT FROM AUTHOR]

Highlights • The physical and chemical effects of SCMs on cementitious mortars can be decoupled. • Neither too coarse nor too fine SCM particles produce optimal physical contribution. • Chemical contribution from SCMs is more from siliceous than calcareous fly ashes. • Role of particle packing in strength development is more for lower w/b systems. • Physical filler effect always has a positive influence on the bound water content. Abstract Studies on understanding the reactivity of alternative materials are typically performed on paste mixtures. This study attempts to explore the contribution of supplementary cementing materials (SCMs) to the properties of blended cementitious mortars. The strength and microstructural development of mortars are investigated through parameters such as compressive strength, porosity and chemically bound water. In addition, an attempt is made to decouple the physical and chemical contribution of SCMs with the help of inert fillers. The results indicate that there is a desired level of fineness at which an optimal performance from mineral additives is obtained. Further, the decoupling methodology was able to bring out the rate of chemical contribution from the different mineral additives; the delayed pozzolanic activity of Class 'F' fly ash led to significant chemical contribution at later ages. Unlike the compressive strength, where the physical filler effect did not uniformly result in a contribution to strength, the results for bound water always show a positive contribution from the filler effect. [ABSTRACT FROM AUTHOR]

Abstract In this study, a magnetic micro-particle conditioning–pressurized vertical electro-osmotic dewatering (MPEOD) process with magnetic micro-particle conditioning–drainage under gravity–mechanical compression–electrical compression (MMPC–DG–MC–EC) stages was established to study the distribution and migration of water, extracellular polymeric substances (EPS), and other organic matter in the activated sludge (AS) matrix at each stage. Results showed that the MPEOD process could attain 53.52% water content (WC) in dewatered AS with bound water (BW) and free water (FW) reduction rates of 82.97% and 99.67%, respectively. The coagulation and time-delayed magnetic field effects of magnetic micro-particles (MMPs) along the MMPC–DG–MC stages initiated the transformation of partial BW to FW in AS. EC had a coupling driving effect of electro-osmosis and pressure on BW, and the changes in pH and temperature at EC stage induced the aggregation of AS flocs and the release of partial BW. Additionally, MMPs dosing further improved the dewatering performance of AS by acting as skeleton builders to provide water passages. Meanwhile, MMPs could disintegrate sludge cells and EPS fractions, thereby reducing tryptophan-like protein and byproduct-like material concentrations in LB-EPS as well as protein/polysaccharide ratio in AS matrix, which could improve AS filterability. At EC stage, the former four Ex/Em regions of fluorescence regional integration analysis for EPS were obviously reduced, especially the protein-like substances in LB- and TB-EPS, which contributed to improvement of AS dewaterability. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Dredging operations produce sediment masses that require chemical conditioning and dewatering before disposing of dredged sediments. Conventional chemical conditioners have difficulty removing the bound water parceled in extracellular polymeric substances (EPS), and the removal of bound water determines the dewatering ratio and the rate of sedimentation. In this study, the conventional conditioners FeCl 3 , Al 2 (SO 4 ) 3 , and cationic polyacrylamide (CPAM) and a new covalently-bound hybrid coagulant (CBHyC) were investigated for dewatering sediments in laboratory conditions that simulated real-world conditions. The water content of dewatered cakes was 61.4–68.3% for sediment conditioned with FeCl 3 , Al 2 (SO 4 ) 3 , and CPAM, while the water content was 52.6% with CBHyC. CBHyC achieved a setting rate that was 66–359% faster than conventional conditioners, decreased specific resistance to filtration (SRF) by 72–86% compared with conventional conditioners. CBHyC achieved the best sediment dewaterability due to its structure, which consists of hydrophobic group of a long carbon chain and hydrophilic groups of Fe-O-Si complexes and quaternary ammonium. This structure increases electrical neutralization ability and bridging effects, allowing formation of large dense flocs in sediments. Moreover, CBHyC also functioned as a surfactant, dissolving EPS (approximately 59.7%), especially proteins (approximately 59.9%) and humic substances (approximately 25.4%), from the sediment into water. The result was approximately 37.1% bound water parceled in EPS was transformed into free water. Lastly, the sediment conditioned with CBHyC exhibited a discontinuous and porous structure; thus, the water was more likely to flow quickly outward from interior locations. These results demonstrate the potential application of CBHyC for high efficiency and rapid dewatering of dredged sediments. [ABSTRACT FROM AUTHOR]

This study visually tracked the micro-spatial water distribution in bio-flocs of waste activated sludge through in situ synchrotron X-ray computed microtomography. Primarily, the two fractions of bound water, the vicinal water adhering to the surface of organic compositions and the interstitial water mechanically trapped in the net-like structure of bio-flocs, were proposed based on the cross-section imaging results. Furthermore, the determinants on bound water occurrences were explored in terms of viscoelastic acoustic responses of extracellular polymeric substances (EPS). The joint roles of hydrophilic substance removal, EPS aggregation compaction and colloidal instability of sludge flocs in bound water reduction were confirmed by the strong correlations (Pearson correlation coefficient, R p  > 0.95, p-value<0.04) among protein levels of EPS, EPS viscosity and bound water contents. Accordingly, providing adhering sites for vicinal water and forming bio-flocs with high viscosity for trapping interstitial water were proposed to be the contributions of EPS on bound water occurrences. [ABSTRACT FROM AUTHOR]

Modified phosphogypsum (MPG) was developed to improve dewaterability of sewage sludge, and dewatering performance, properties of treated sludge, composition and morphology distribution of EPS, dynamic analysis and multiple regression model on bound water release were investigated. The results showed that addition of MPG caused extracellular polymeric substances (EPS) disintegration through charge neutralization. Destruction of EPS promoted the formation of larger sludge flocs and the release of bound water into supernatant. Simultaneously, content of organics with molecular weight between 1000 and 7000 Da in soluble EPS (SB-EPS) increased with increasing of EPS dissolved into the liquid phase. Besides, about 8.8 kg•kg −1 DS of bound water was released after pretreatment with 40%DS MPG dosage. Additionally, a multiple linear regression model for bound water release was established, showing that lower loosely bond EPS (LB-EPS) content and specific resistance of filtration (SRF) may improve dehydration performance, and larger sludge flocs may be beneficial for sludge dewatering. [ABSTRACT FROM AUTHOR]

A combined modified phosphogypsum (MPG) and acetic acid (HAC) addition was performed to pretreat sewage sludge for better dewaterability, and dewatering performance, sludge flocs morphology, properties of treated sludge, composition and morphology distribution of extracellular polymeric substances (EPS), bound water release dynamic were investigated. Results suggested that combined addition could highly improve sludge dewatering compared to single addition. Furthermore, after pretreatment, stable sludge network was disintegrated and massive loosely bound EPS (LB-EPS) were destroyed into supernatant, thus increasing amount of organics with molecular weight between 1000 and 7000 Da in soluble EPS (SB-EPS). Simultaneously, about 9.5 kg kg −1 DS (Dry solids) of bound water was released from sludge network. [ABSTRACT FROM AUTHOR]

Poly (ethylene-vinylalcohol) copolymer (EVOH) films under different humidity conditions were studied by THz absorption spectroscopy to obtain information about the bound water. An intermolecular stretching mode of bound water was observed at around 6 THz, similar to that in liquid water; and the very weak libration mode indicates that this water is frozen. By generalized two-dimensional correlation spectroscopy (2DCOS) and perturbation-correlation 2D moving window (PCMW2D) correlation spectroscopy, the bound water was categorized into three types: frozen with amorphous structure (I), liquid-like with librational motion (II), and nearest neighboring water with weaker hydrogen bonding network (III). The strongly inhomogeneous intermolecular stretching band of water I shows that the frozen bound water is amorphous. The frequency shift of this band in water III indicates a weaker hydrogen bonding network around the ethylene group. Changes in the films' oxygen permeability are discussed and correlated with the dynamics of bound water. [ABSTRACT FROM AUTHOR]

RuO2 is an unparalleled electrode with wider applications. Chloride, bound water, and surface stoichiometry are the inherent residues of RuO2 left upon the high-temperature pyrolysis of a RuCl3⋅xH2O precursor. Although the electrocatalytic properties of RuO2 for specific applications have been studied extensively, there is a paucity of studies linking the intrinsic electron-transfer (ET) activity of RuO2 with the oxide preparation temperature-dependent inherent residual parameters. This paper presents the intrinsic ET activity-oxide residue correlations for RuO2 electrodes. The ET kinetic parameters were estimated using a surface oxide-sensitive Fe3+/Fe2+ redox probe by rotating disc electrode voltammetry. Oxide powder-based electrodes (RuO2 powder-PVC/Pt-modified electrodes), which were fabricated conveniently at room temperature even with high-temperature oxides, were used instead of the traditional thermally prepared electrodes to circumvent the primary problems at the coating|support interface and inefficient chloride removal. RuO2 powders prepared at five temperatures (Tprep), i.e., 300, 400, 500, 600, and 700 °C, were used for electrode fabrication. The results showed that the electron exchange rate was highest for the 400 °C RuO2 electrode, and it was independent of the Tprep in the range 500 to 700 °C. The oxide powders were characterized using a range of techniques. The measured intrinsic ET activity and the associated structural correlation over the Tprep range 300-700 °C suggest that the best activity of the 400 °C electrode can be attributed to the optimal chloride and bound water contents in a completely formed rutile surface layer containing the catalyst sites of a particular nature with the highest electroactivity. [ABSTRACT FROM AUTHOR]

The use of fat to support the energy needs of reproduction (i.e. capital breeding) has been studied in a diversity of taxa. However, despite reproductive output (i.e. young or eggs) being approximately 70% water, little is known about the availability of internal resources to accommodate the hydric demands of reproduction. Recent research suggests that dehydration increases the catabolism of muscle as a means of maintaining water balance. Accordingly, we investigated the interactive effects of reproductive investment and water deprivation on catabolism and reproductive output in female Children's pythons (Antaresia childreni). Both reproductive and nonreproductive females were either provided water ad libitum or were water-deprived for three weeks at the time when reproductive females were gravid. We found that water-deprived reproductive females had, in general, greater body mass loss, epaxial muscle loss, plasma osmolality and plasma uric acid concentrations relative to the other groups. Furthermore, water-deprived females had similar clutch sizes compared with females with access to water, but produced lighter eggs and lower total clutch masses. Our results provide the first evidence that selective protein catabolism can be used to support water demands during reproduction, and, as a result, these findings extend the capital breeding concept to non-energetic resources. [ABSTRACT FROM AUTHOR]

Agar is an interesting and versatile biopolymer capable of forming hydrogels useful in different applications. In particular, in the field of Cultural Heritage agar gels are often used as tools for cleaning the surfaces of artifacts. Agar gels are thermoreversible, peelable materials, exhibiting high retention of water and an intrinsic cleaning capability that can be increased and modulated by loading different cleaning agents. Agar gels are able to solubilize and retain dirt, and allow a confined release of the liquid phase, which is especially important when they are applied on water sensitive substrates. A detailed knowledge of the role of water in agar gels and of water/agar interactions is important to fully understand the properties and performances of agar gels as cleaning materials. Here we report the results of a systematic study aimed at exploring the water state and the types of water (i.e. bound non-freezable, bound freezable and freezable bulk-like) in agar hydrogels prepared from four different types of commercial agar powders. The influence of agar concentration on the water behaviour in the hydrogels was also investigated. The total water content, the identification and quantification of the different types of water was carried out by gravimetric, thermogravimetric and calorimetric analyses, while water mobility and localization in the gel network were investigated by unilateral 1 H NMR. Moreover, 1 H NMR depth profiles of agar gels applied on Noto stone specimens were collected to monitor the gel deformation due to water release and to evaluate the ability of the gel in controlling the water release into a porous material. [ABSTRACT FROM AUTHOR]

Abstract: Over the summer of 2015, the National Water Center hosted the National Flood Interoperability Experiment (NFIE) Summer Institute. The NFIE organizers introduced a national‐scale distributed hydrologic modeling framework that can provide flow estimates at around 2.67 million reaches within the continental United States. The framework generates discharges by coupling a given Land Surface Model (LSM) with the Routing Application for Parallel Computation of Discharge (RAPID). These discharges are then accumulated through the National Hydrography Dataset Plus stream network. The framework can utilize a variety of LSMs to provide the runoff maps to the routing component. The results obtained from this framework suggested that there still exists room for further enhancements to its performance, especially in the area of peak timing and magnitude. The goal of our study was to investigate a single source of the errors in the framework's discharge estimates, which is the routing component. The authors substitute RAPID which is based on the simplified linear Muskingum routing method by the nonlinear routing component the Iowa Flood Center have incorporated in their full hydrologic Hillslope‐Link Model. Our results show improvement in model performance across scales due to incorporating new routing methodology. [ABSTRACT FROM AUTHOR]

Thermogravimetry is a technique measuring mass change during programmed heating. In soil analysis, it is used for determination of content of volatile fractions, thermally labile and stable fractions of soil organic matter and minerals. One method of data analysis uses the determination of mass losses in 10 °C temperature areas. In the past, their mutual correlation revealed several larger temperature areas of mass losses, which appeared to be universal for all types of soils equilibrated at the same relative humidity. However, it is unclear if mass losses in these temperature areas are connected with biogeochemical functions or processes in soil. In this work, using data from > 300 soils of different types, geographical origin, and land uses we demonstrate their linear correlation with content of organic C, total N and clay content and biological activity or their combinations. In particular, the results showed that mass losses between 200 and 300 °C, which is related to thermally labile fraction, correlates best with total organic C and less with total organic N. From 300 to 450 °C represents a more stabilized soil organic matter pool and can be best described by either by C or N contents. Mass loss 450–550 °C correlates strongly with clay content, which suggests a connection to organo-clay complexes. The low temperature interval of 30–200 °C, which corresponded to weakly and strongly bound water showed a strong connection with clay content, but a weaker connection to microbial activity. The developed equations were corrected and verified using additional soil sample sets. The correlations along with their universal applicability lead to conclusion about the possible connection of mass losses in these temperature areas to, still unknown, biogeochemical soil functions. The obtained equations may represent a new approach of rapid and universally applicable “mathematical” fractionation requiring only contents of soil organic carbon, total nitrogen, clay and water in soil equilibrated at 76% relative humidity. [ABSTRACT FROM AUTHOR]

Enzyme application has gained importance over the past decade in bioprocess, biomedical, and pharmaceutical fields. We found that polyglycerol dendrimers (PGDs), which are biocompatible molecules, can recover alcohol dehydrogenase (ADH) from aqueous solution under elevated temperature. A low concentration of PGD (5 wt.%) is sufficient for the recovery of high enzymatic activity, although a high concentration (25–75 wt.%) of glycerol is generally required to stabilize ADH. The enzymatic activity of ADH in suspension with PGDs is over 60% but it is only 10% in that with glycerol. The results of osmolarity and spin-lattice relaxation time (T1) of water measurements in the presence of PGDs suggest that increased amounts of bound water to PGD molecules trigger aggregation along with the direct interaction with ADH. PGDs therefore represent good potential additives for direct recovery of enzymes from aqueous solutions. [ABSTRACT FROM AUTHOR]

Dewatering is recognized as an important method for treating sewage sludge before its disposal. In this paper, the nonionic surfactant Tween-20 was used for the first time to improve the dewaterability of sewage sludge during bioleaching. The specific resistance to filtration (SRF), water content (WC) and bound water content (BW) of the sludge cake were used to evaluate sludge dewaterability. The results indicated that a 1 g/L Tween-20 dosage with an inoculum ratio of 20%, a S0 dosage of 2 g/L and a FeSO4 · 7H2O dosage of 10 g/L provided oxidation efficiencies up to 100% for Fe2+ and 65.8% for S0. The SRF of the bioleached sludge decreased to as low as 0.81 × 1012 m/kg from the initial 12.6 × 1012 m/kg for raw sludge. A WC of 47.16% was achieved while 48.1% of BW was released during bioleaching. The results from this study indicate that adding of an appropriate amount of Tween-20 to sewage sludge is a promising method to enhance dewaterability by bioleaching. [ABSTRACT FROM AUTHOR]

Interest in producing heat and power using municipal wastewater sewage sludge as a fuel is increasing worldwide. Since its water content is initially high, sludge must be dewatered and further dried if it is to serve as an effective fuel for combustion. However, to maximize net energy production, the drying processes must use as little energy as possible. The water content in sewage sludge comprises both unbound and bound water. Unbound water content is typically extracted using a number of mechanical dewatering techniques. In terms of total solids content (TS), dewatering processes can take sludge from an initial 3–5% to a more solid 25–45% TS with minimal energy expenditure. However, this level of dryness is not sufficient for effective combustion. To produce an effective fuel, TS levels must be increased. Achieving high level of dryness involves removing any remaining unbound water and substantial bound water content as well. Heat is normally applied to accomplish this by changing the phase of the water from liquid to vapor. Although dewatering is energy-efficient, thermal drying is not. The energy used to thermally dry sludge can be two orders of magnitude greater than the energy used for dewatering. Therefore, to expend as little energy as possible to achieve the needed dryness, conventional dewatering processes clearly must be improved. This paper describes work carried out to identify promising ways to efficiently enhance the dewatering and drying of sewage sludge. Available dewatering approaches were reviewed and experiments were carried out to examine the relative effects of temperature, atmospheric pressure, and high-power ultrasound. The high-power ultrasound approach seemed to be particularly effective. The mechanisms involved include atomization, microstructural effects, cavitation, and the sponge effect, which work to reduce both internal and external resistances. Applied in the right way, ultrasound could become a very effective way to enhance mechanical dewatering. [ABSTRACT FROM AUTHOR]

Abstract: This study aims at measuring the moisture transformation and distribution of Tricholoma matsutake (T. matsutake) during the hot‐air drying process, to provide theoretical guidance for drying optimization of T. matsutake. Pileus and stipe of T. matsutake were dried at 55 °C for 14 hr. During the hot‐air drying, spin‐spin relaxation measurements and magnetic resonance image were used to determine the water composition and the moisture transformation, respectively. Results showed that three categories of moisture including free, immobilized, and bound water were presented in T. matsutake. During the drying process, the immobilized water was the major, free and immobilized water were active, while bound water was stable. The measurements of moisture transformation and distribution in T. matsutake by low field nuclear magnetic resonance suggested that hot‐air drying was an inhomogeneous drying process. Practical applications: T. matsutake is rich of nutritional and bioactive compounds. The fresh T. matsutake contains large amount of water, therefore, the dehydration process is essential for the preservation of T. matsutake. Hot‐air drying has been widely used in food preservation. Moisture content and states are key parameters affecting the quality of dehydrated foods. However, no data have shown the dynamics of moisture transformation and distribution of T. matsutake during the hot‐air drying process. This study aims at measuring the profiles of moisture during hot‐air drying by low field nuclear magnetic resonance (LF‐NMR) and NMR proton density imaging, which could help to optimization the drying of T. matsutake or other edible fungi. [ABSTRACT FROM AUTHOR]

Microwave drying of coal has the advantage of volumetric and selective heating, which saves energy and time. However, comprehensive assessment of the moisture migration during microwave drying is lacking. In this study, the low-field nuclear magnetic resonance (LF-NMR) was used for moisture characterization during microwave drying. Moisture migration occurs first in larger pores, whereas the smaller pores appear to remain water-saturated. As the microwave power increases, the drying capacity and drying rate both increase because high-power microwave can open the blind pores to promote moisture seepage. Furthermore, moisture migration during microwave drying is usually directional (i.e., along the bedding plane). The LF-NMR method provides a framework for the determination of moisture migration of coals. [ABSTRACT FROM AUTHOR]

The bark-water relation and the moisture transport in bark are essential for the living tree but also for the industrial utilization of bark. Thus the bark-water relation of beech (Fagus sylvatica ) and spruce (Picea abies ) have been studied in the present work. The sorption isotherms were determined at 35°C for both wood and bark and the water diffusivity was measured under steady state conditions (cup method) and under unsteady state conditions, i.e. via sorption test. The sorption isotherms were calculated based on the Hailwood-Horrobin (HH) model. It was observed that beech wood and bark have a similar hygroscopic behavior, whereas spruce bark is more hygroscopic than spruce wood in all the relative humidity (RH) ranges. The radial diffusivity was in the range 1.2 ⋅ 10-11-2.2 ⋅ 10-11 m² s-1 for spruce and beech bark, respectively, when the driving force of the diffusion is the gradient of bound water. [ABSTRACT FROM AUTHOR]

Water loss is an early onset indicator of osteoarthritis. Although Raman spectroscopy (RS) holds the potential for measurement of cartilage hydration, the knowledge of Raman OH-stretch bands of biological tissue is very limited. We assesed here the sensitivity of RS to identify and classify water types in the cartilage. Raman spectrum measurements over the high wavenumber range were employed to identify different water fractions in articular cartilage. Raman spectra were collected from wet and sequentially dehydrated cartilage along with pure collagen type II and chondroitin sulfate standards. OH-stretch band of cartilage is dominated by mobile water, up to 95% of total intensities. We identified six peaks in cartilage spectrum using second-derivative analysis: peaks at 3200 and 3650 cm-1 are associated with organic matrix (both collagen and proteglycan) and matrix-bound water molecules. Peaks at 3250, 3453, and 3630 cm-1 are associated with collagen and collagen-related water molecules, whereas the peak at 3520 cm-1 is associated with proteoglycan (PG) and PG-related water molecules. The current work is the first thorough analysis of the Raman OH-stretch band of the cartilage and with the knowledge generated by this study, it may now be possible to study on cartilage hydration by RS. [ABSTRACT FROM AUTHOR]

Hypothesis Nanocellulose gels form a new category of sustainable soft materials of industrial interest for a wide range of applications. There is a need to map the rheological properties and understand the mechanism which provides the colloidal stability and gelation of these nanofibre suspensions. Experiments TEMPO (2,2,6,6,-tetramethylpiperidine-1-oxyl)-oxidised cellulose nanofibre gels were investigated at different fibre concentrations, pH and ionic strength. Dynamic and cyclic rheological studies was performed to quantify gel behaviour and properties. Gels were produced at different pH and salt contents to map and understand colloidal stability of the nanocellulose gel. Findings Rheology indicates gelation as a transitionary state starting at a fibre concentration of 0.1 wt.%. The colloidal stability of the nanocellulose gel network is controlled by pH and salt, whereas fibre concentration mainly dictates the dynamic rheological properties. Decreasing pH and adding salt destabilises the gel network by eluting bound water which is correlated with the decrease in electrostatic repulsion between fibres. The gelation and colloidal stability of these nanocellulose gels is driven by electrostatic forces and the entanglement ability of the fibrous system to overlap. [ABSTRACT FROM AUTHOR]

The optical dispersion and water content of human liver were experimentally studied to estimate the optical dispersions of tissue scatterers and dry matter. Using temporal measurements of collimated transmittance [Tc(t)] of liver samples under treatment at different glycerol concentrations, free water and diffusion coefficient (Dgl) of glycerol in liver were found as 60.0% and 8.2 × 10−7 cm2∕s, respectively. Bound water was calculated as the difference between the reported total water of 74.5% and found free water. The optical dispersion of liver was calculated from the measurements of refractive index (RI) of tissue samples made for different wavelengths between 400 and 1000 nm. Using liver and water optical dispersions at 20°C and the free and total water, the dispersions for liver scatterers and dry matter were calculated. The estimated dispersions present a decreasing behavior with wavelength. The dry matter dispersion shows higher RI values than liver scatterers, as expected. Considering 600 nm, dry matter has an RI of 1.508, whereas scatterers have an RI of 1.444. These dispersions are useful to characterize the RI matching mechanism in optical clearing treatments, provided that [Tc(t)] and thickness measurements are performed during treatment. The knowledge of Dgl is also important for living tissue cryoprotection applications. [ABSTRACT FROM AUTHOR]

Purpose: This study explored the potential of combining the use of moisture sorption isotherms and dielectric relaxation profiles of starch and sodium starch glycolate (SSG) to probe the location of moisture in dried and hydrated samples. Methods: Starch and SSG samples, dried and hydrated, were prepared. For hydrated samples, their moisture contents were determined. The samples were probed by dielectric spectroscopy using a frequency band of 0.1 Hz to 1 MHz to investigate their moisture-related relaxation profiles. The moisture sorption and desorption isotherms of starch and SSG were generated using a vapor sorption analyzer, and modeled using the Guggenheim-Anderson-de Boer equation. Results: A clear high frequency relaxation process was detected in both dried and hydrated starches, while for dried starch, an additional slower low frequency process was also detected. The high frequency relaxation processes in hydrated and dried starches were assigned to the coupled starch-hydrated water relaxation. The low frequency relaxation in dried starch was attributed to the local chain motions of the starch backbone. No relaxation process associated with water was detected in both hydrated and dried SSG within the frequency and temperature range used in this study. The moisture sorption isotherms of SSG suggest the presence of high energy free water, which could have masked the relaxation process of the bound water during dielectric measurements. Conclusion: The combined study of moisture sorption isotherms and dielectric spectroscopy was shown to be beneficial and complementary in probing the effects of moisture on the relaxation processes of starch and SSG. [ABSTRACT FROM AUTHOR]

Temperature dependencies of the DC conductivity of kaolin and illite are measured from 20 °C up to 450 °C using “as received” samples and samples after heating to 400 °C and 450 °C. Release of physically bound water (PBW) from green kaolin shows two maxima, at 55 °C and 298 °C. Release of the PBW from green illite takes place in 3 steps at 72 °C, 186 °C, and 298 °C. Up to 200 °C, the dominant charge carriers are H + and OH – ions in both materials. At higher temperatures, alkali ions (both Na + and K + in kaolin, prevalently K + in illite) are the dominant charge carriers with the conduction activation energy of 1.19 ± 0.02 eV in kaolin and of 1.12 ± 0.02 eV in illite. Above 400 °C, dehydroxylation runs in illite. Due to this process, the DC conductivity of illite increases; in partly dehydroxylated illite, higher conduction activation energy (1.22 eV) indicates that alkali metal ions are moving in a more disordered structure. In kaolin, dehydroxylation starts only above 450 °C. [ABSTRACT FROM AUTHOR]

For Portland cements, Powers' model provides a simple method for calculating the total amount of water bound by cement hydration (both physically and chemically bound). On the other hand, no such simple model is available for other types of cements that are of increasing interest, such as calcium aluminate cements and calcium sulfoaluminate cements. The main uncertainty for these types of cement regards the amount of physically bound water in the hydrates, while the amount of chemically bound water can be calculated, e.g., by thermodynamic modeling. In this paper, a simple approach for estimating the total amount of bound water of different cements is presented. This novel approach consists in measuring the rate of heat liberation of cement pastes made with the same cement, starting at low water-to-cement ratio ( w/ c) and increasing it steadily. As the cumulative heat of hydration reaches a plateau for a given w/ c and does not increase for further increases in the water amount, this w/ c is interpreted as total water demand of the cement. The method is tested with a Portland cement, showing that it is in broad agreement with Powers' model. First results for calcium aluminate cement and calcium sulfoaluminate cement are presented, from which estimations of the amount of physically and chemically bound water are obtained. [ABSTRACT FROM AUTHOR]

Aim Capillarity theory predicts that the pore volume infiltrated by a liquid in a body with tubular capillaries is directly proportional to the capillary radius. The expected volume available for infiltration is the loosely bound water volume, which can be related to the capillary radii. We tested the hypothesis that the proportion of the pore volume infiltrated by resin infiltrant ( V r a t i o r e sin ) is correlated and agrees with the proportion of the pore volume with loosely bound water ( V r a t i o a 2 ). Design Seven human fluorotic third molars (4 unerupted and 3 erupted; TF scores 4 to 7; fluoride content of inner coronal dentin ranged from 143 to 934 μg Fluoride/g) were prepared and resin infiltration was performed during 10 min in fluorotic enamel ground sections. Penetration depths were measured (polarizing microscopy and CLSM) and mineral volume and non-mineral volumes were measured at histological points (n = 92) along transversal lines traced from the enamel surface to the enamel-dentin junction. Results No well-mineralized surface layer was found. Infiltration depths ranged from 250 μm to 900 μm. V r a t i o r e sin ranged from 1.8 to 17.7% (mean of 10.13% ± 4.1%), was lower than V r a t i o a 2 (p < 0.00001 Hedge’s g = 1.51, 95% CI: 1.18/1.83), and correlated positively with V r a t i o a 2 (R = 0.684; 95% CI: 0.557/0.780) and negatively with the air volume remained after infiltration (R = −0.79; 95% CI: −0.698/−0.780). V r a t i o a 2 exceeded V r a t i o r e sin in 5% (1/4 of V r a t i o a 2 ) on average. Conclusion V r a t i o a 2 and V r a t i o r e sin correlated well, but lacked good agreement. Organic matter, firmly bound water and air remained in enamel pores after resin infiltration. [ABSTRACT FROM AUTHOR]

Colorectal carcinoma is a major health concern worldwide and its high incidence and mortality require accurate screening methods. Following endoscopic examination, polyps must be removed for histopathological characterization. Aiming to contribute to the improvement of current endoscopy methods of colorectal carcinoma screening or even for future development of laser treatment procedures, we studied the diffusion properties of glucose and water in colorectal healthy and pathological mucosa. These parameters characterize the tissue dehydration and the refractive index matching mechanisms of optical clearing (OC). We used ex vivo tissues to measure the collimated transmittance spectra and thickness during treatments with OC solutions containing glucose in different concentrations. These time dependencies allowed for estimating the diffusion time and diffusion coefficient values of glucose and water in both types of tissues. The measured diffusion times for glucose in healthy and pathological mucosa samples were 299.2 ± 4.7 s and 320.6 ± 10.6 s for 40% and 35% glucose concentrations, respectively. Such a difference indicates a slower glucose diffusion in cancer tissues, which originate from their ability to trap far more glucose than healthy tissues. We have also found a higher free water content in cancerous tissue that is estimated as 64.4% instead of 59.4% for healthy mucosa. [ABSTRACT FROM AUTHOR]

Water diffusion in cellulose was studied via two-phase Kärger model and the propagator method. In addition to ruling out anomalous diffusion, the mean squared displacements obtained at different diffusion times from the Kärger model allowed to characterize the system's phases by their average confining sizes, average connectivity and average apparent diffusion coefficients. The two-phase scheme was confirmed by the propagator method, which has given insights into the confining phase-geometry, found consistent with a parallel-plane arrangement. Final results indicate that water in cellulose is confined in two different types of amorphous domains, one placed at fiber surfaces, the other at fiber cores. This picture fully corresponds to the phenomenological categories so far used to identify water in cellulose fibers, namely, free and bound water, or freezing and non-freezing water. [ABSTRACT FROM AUTHOR]

Hygroscopic food materials contain free (FW) and bound (BW) water in different cellular environments. In-depth understanding of the mechanisms of moisture migration from different cellular environments during drying is crucial for optimising heat and mass transfer as well as for obtaining better quality dried foods. Therefore, the main aim of the present work is to investigate the transportation mechanisms of FW and BW during drying. Experiments were performed on the potato tissue using 1 H-NMR T 2 relaxometry to uncover the mechanisms involved in FW and BW transportation. The results have confirmed the view that BW migrates after the rupture of the cell membranes. It is interesting to highlight that the cell membranes rupture at different stages of drying rather than collapsing at one time. The membrane collapse depends predominantly on the penetration rate of heat energy and the pressure gradient between intracellular and intercellular environments. All test results suggest that most of the cell membranes rupture at the middle stage of drying where the moisture content is about 2–4 kg/kg (db.). Furthermore, the moisture distribution profile confirmed that some moisture remained around the centre of the dried sample although the surface of the sample became dry. [ABSTRACT FROM AUTHOR]

X-ray scattering (XRS) experiments have been performed on multi-layered graphene oxide (GO) paper. GO can be easily hydrated as water naturally intercalates in the hydrophilic nanostructure. The effect of the intercalated water on the XRS signals is measured during dehydration under thermal treatment in the temperature range 298-473 K as well as during hydration under saturated water vapour pressure. A simple modelling of the XRS signals by taking into account the presence and the type of intercalated water (bound water or physisorbed water) is introduced. It allows an explanation of the variations of intensity and position of XRS reflections observed experimentally. [ABSTRACT FROM AUTHOR]

Earlywood (EW) and latewood (LW) have different hygromechanical behaviors, if subjected to relative humidity (RH) variations. To understand this effect better, the adsorption mechanisms of EW and LW of Douglas fir were studied by 2D 1H NMR relaxometry under conditions of equilibrium moisture content (EMC) at 20°C. Two bound water components were detected with relaxation times T1 and T2 indicating that they are located in distinct environments but these are similar in EW and LW. Sorption isotherms were calculated and analyzed based on the sorption model of Dent. A difference of sorption energy between the two water components is in agreement with their mobility difference observed on T1 - T2 correlation spectra. Moreover, for the two bound water components, EW and LW exhibit different sorption isotherms at high RH. This may be attributed to a difference of adsorption capacity. Based on the macrofibril models provided by the literature, the following hypothesis is proposed: bound water components are located in lamellar and lenticular areas, both leading to possible deformations. [ABSTRACT FROM AUTHOR]

The wood drying rate was determined at five different relative humidities (RHs) using time domain nuclear magnetic resonance (TD-NMR). The objective of this study was to obtain the drying rate of bound water and free water, and to also build a relation between RH and drying rate. Two kinds of wood species, Qingpi poplar (Populus platyphylla var. glauca) and Pinus sylvestris var. mongolica Litv. were employed for the spin-spin relaxation time (T2) measurement. The mass of free water and bound water during drying were obtained at the same time. The results indicated that the poplar specimens had a higher fiber saturation point (FSP). For both wood species, free water decreases quickly, which contributes to the main drying, especially at the beginning of drying, and still exists even when the moisture content (MC) is below the FSP. Bound water decreases slowly, and its equilibrium content ranges from less than 10% to more than 20%, in the order from lower RH to higher RH. In addition, the drying rate decreases linearly with increasing RH. [ABSTRACT FROM AUTHOR]

Three representative rock types (limestone, sandstone, and shale) and glauconite samples collected from Ewekoro Quarry, eastern Dahomey Basin in Nigeria were characterized using low field 2 MHz and 20 MHz Nuclear Magnetic Resonance (NMR) techniques. NMR T 2 relaxation time decay measurement was conducted on disc samples under partial water-saturation and full water-saturation conditions using CPMG spin-echo routine. The T 2 relaxation decay was converted into T 2 distribution in the time domain to assess and evaluate the pore size distribution of the samples. Good agreement exists between water content from T 2 NMR distributions and water imbibition porosity (WIP) technique. Results show that the most useful characteristics to discriminate the different facies come from full saturation NMR 2 MHz pore size distribution (PSD). Shale facies depict a quasi-unimodal distribution with greater than 90% contribution from clay bound water component ( T 2s ) coupled to capillary bound water component ( T 2i ) centred on 2 ms. The other facies with well connected pore structure show either bimodal or trimodal T 2 distribution composed of the similar clay bound water component centred on 0.3 ms and quasi-capillary bound water component centred on 10 ms. But their difference depends on the movable water T 2 component ( T 2 l ) that does not exist in the glauconite facies (bimodal distribution) while it exists in both the sandstone and limestone facies. The basic difference between the limestone and sandstone facies is related to the longer T 2 coupling: T 2i and T 2 l populations are coupled in sandstone generating a single population which convolves both populations (bimodal distribution). Limestone with a trimodal distribution attests to the fact that carbonate rocks have more complex pore system than siliclastic rocks. The degree of pore connectivity is highest in sandstone, followed by limestone and least in glauconite. Therefore a basic/quick NMR log run on samples along a geological formation can provide precise lithofacies characterization with quantitative information on pore size, structure and distributions. [ABSTRACT FROM AUTHOR]

The microenvironment of water droplets of nonionic polyoxyethylene (4) lauryl ether reverse micelles was investigated using infrared, ultraviolet-visible and nuclear magnetic resonance spectroscopy, also by dynamic light scattering. The different influence of kosmotropic and chaotropic ionic additives on the microstructure of reverse micelles was revealed. The values of chemical shift in the presence of structure-breaking perchlorate ions are higher than their values in case of structure-making acetate ions according to measurements by proton magnetic resonance spectroscopy. Deconvolution of the O H stretching vibrational absorption spectra in the region of 3000–3800 cm −1 into three subpeaks with a Monte Carlo method showed that perchlorate ions promote an increasing of free water fraction in the water pools of the reverse micelles, whereas acetate ions support formation of bound water. Influence of salt additives results in slight different sizes of water droplets, measured by dynamic light scattering method. Different influence of kosmotropic and chaotropic anions on binding constant K b of optical probe to ethylene oxide groups was revealed. [ABSTRACT FROM AUTHOR]

Infragravity waves (0.005–0.04 Hz) can dominate the water motion close to shore on low sloping beaches and play a significant role in beach and dune erosion. A new field data set of water surface elevation at 15 cross-shore locations on a dissipative, fetch-unlimited beach is analysed to investigate the forcing and surf zone behaviour of infragravity waves during a wide range of offshore wave conditions ( H o =0.38–3.88 m; T p =6–20 s). Infragravity waves approach the shore as bound waves lagging slightly (~4 s) behind the short wave (0.04–0.33 Hz) envelope and are released in the surf zone as free waves. Infragravity wave heights of up to 1 m are measured close to shore and are best predicted using an offshore forcing parameter that represents the short wave energy flux ( H o 2 T p ). Considerable infragravity dissipation is observed in the surf zone and dissipation increases with offshore wave energy. Dissipation is highly frequency-dependant and a frequency-domain Complex Empirical Orthogonal Function analysis reveals (quasi-)standing waves at frequencies <0.017 Hz, but an increasingly progressive wave pattern at higher frequencies with reflection coefficients <0.1, indicative of more than 90% dissipation. Much of the observed dissipation occurs very close to shore and the dependence of the reflection coefficient on a normalised bed slope parameter implies that energy at high infragravity frequencies is dissipated by wave breaking, since these frequencies fit into a mild sloping regime. This is supported by the results of bispectral analysis which show predominantly infragravity-infragravity interactions in shallow water and the development of infragravity harmonics indicative of steepening and eventual breaking of the infragravity waves. [ABSTRACT FROM AUTHOR]

Background: Many important geochemical and biogeochemical reactions occur in the mineral/formation water interface of the highly abundant mineral, goethite [α-Fe(OOH)]. Ab initio molecular dynamics (AIMD) simulations of the goethite α-FeOOH (100) surface and the structure, water bond formation and dynamics of water molecules in the mineral/aqueous interface are presented. Several exchange correlation functionals were employed (PBE96, PBE96 + Grimme, and PBE0) in the simulations of a (3 × 2) goethite surface with 65 absorbed water molecules in a 3D-periodic supercell (a = 30 Å, FeOOH slab ~12 Å thick, solvation layer ~18 Å thick). Results: The lowest energy goethite (100) surface termination model was determined to have an exposed surface Fe that was loosely capped by a water molecule and a shared hydroxide with a neighboring surface Fe. The water molecules capping surface Fe ions were found to be loosely bound at all DFT levels with and without Grimme corrections, indicative that each surface Fe was coordinated with only five neighbors. These long bonds were supported by bond valence theory calculations, which showed that the bond valence of the surface Fe was saturated and surface has a neutral charge. The polarization of the water layer adjacent to the surface was found to be small and affected only the nearest water. Analysis by density difference plots and localized Boys orbitals identified three types of water molecules: those loosely bound to the surface Fe, those hydrogen bonded to the surface hydroxyl, and bulk water with tetrahedral coordination. Boys orbital analysis showed that the spin down lone pair orbital of the weakly absorbed water interact more strongly with the spin up Fe ion. These weakly bound surface water molecules were found to rapidly exchange with the second water layer (~0.025 exchanges/ps) using a dissociative mechanism. Conclusions: Water molecules adjacent to the surface were found to only weakly interact with the surface and as a result were readily able to exchange with the bulk water. To account for the large surface Fe-OH distances in the DFT calculations it was proposed that the surface Fe atoms, which already have their bond valence fully satisfied with only five neighbors, are under-coordinated with respect to the bulk coordination.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Interactions of human serum albumin (10 wt% H 2 O and 0.3 wt% sodium caprylate) with doxorubicin hydrochloride (1 wt%) were studied alone or with addition of HCl (3.6 wt% HCl) using 1 H NMR spectroscopy. A model of hydrated HSA/12DOX was calculated using PM7 method with COSMO showing large variations in the binding constant depending on structural features of DOX/HSA complexes. DOX molecules/ions displace bound water from narrow intramolecular voids in HSA that leads to diminution of freezing-melting point depression of strongly bound water (SBW). Structure of weakly bound water (WBW) depends much weaker on the presence of DOX than SBW because a major fraction of DOX is bound to adsorption sites of HSA. Addition of HCl results in strong changes in structure of macromolecules and organization of water in hydration shells of HSA (i.e., mainly SBW) and in the solution (i.e., WBW + non-bound bulk water). [ABSTRACT FROM AUTHOR]

Low-field Nuclear Magnetic Resonance (NMR) has proved to be a valuable tool for the petrophysical characterization of conventional reservoirs, but its effective application to unconventional reservoirs is still under research. Pore structure characterization of shales is particularly challenging due to the complexity of the pore network and the small size of pores. Using low-field NMR, we performed transverse relaxation (T 2 ) experiments on samples from the Perth Basin, Western Australia. The samples were initially saturated with KCl brine to obtain the total NMR porosity and T 2 distribution, then centrifuged and finally oven-dried at increasing temperatures. T 2 spectra were also acquired after centrifuging and heating the samples. Our results indicate that most of the transverse relaxation occurs below 3 ms in saturated samples and that a conventional centrifuge cannot remove water from the smaller pores, making the commonly accepted clay bound water cut-off unsuitable for shales. Furthermore, the results from NMR experiments performed on the oven-dried shale samples suggest that the water content remains relatively constant after heating them above 65 °C. The calculated T 2 cut-off for clay bound water is between 0.22 and 0.26 ms for the samples studied. The methodology presented in this paper can be replicated in other formations to find a suitable T 2 value for clay bound water, which can be a good indication of potentially producible porosity and can also be used for permeability estimation. [ABSTRACT FROM AUTHOR]

This article presents novel techniques for characterizing the kinetics of the free and bound water in a specimen by performing only one single sorption experiment. By monitoring the time variation of the residual water in a specimen that undergoes a controlled non-isothermal sorption over the range of temperatures of interest, the initial mass of the free and bound water in the specimen, the Arrhenius constants of diffusivity of the free water, and the Arrhenius constants of the rate of dissolution of the bound water can be extracted through a combination of time–temperature transformation and regression. [ABSTRACT FROM PUBLISHER]

The dependence of the Si-O stretching vibration line intensity in the IR spectrum of kaolinite on the humidity of this mineral has been experimentally investigated. The experimental data were interpreted on the basis of density functional theory (DFT) calculations with allowance for the real crystallographic features of the kaolinite sample, determined by structural analysis. Some specific features of the intensity behavior in the plastic state are revealed, which can be used to develop techniques for determining its limits. The differences in the O-H bond lengths and H-O-H angles for the HO molecules adsorbed by basal surfaces and located in the porous space of the mineral are determined. Based on the DFT data, it was found that bond lengths and bond angles for a water molecule adsorbed on the siloxane surface are systematically smaller than for a water molecule adsorbed on the hydroxyl surface. [ABSTRACT FROM AUTHOR]

The effects of physical structure (pore structure) on behavior of water in lignite coal and activated carbon (AC) samples were investigated by using Differential Scanning Calorimetry (DSC) and low-temperature X-ray diffraction (XRD) techniques. AC samples with different pore structures were prepared at 800 °C in steam and the results were compared with that of parent lignite coal. The DSC results confirmed the presence of two types of freezable water that freeze at −8 °C (free water) and −42 °C (freezable bound water). A shift in peak position of free water (FW) towards lower temperature was observed in AC samples compared to the lignite coal with decreasing water loading. The amount of free water (FW) increased with increasing gasification conversion. The amounts of free and freezable bound water (FBW) in AC samples were calculated and correlated to pore volume and average pore size. The amount of FW in AC samples is well correlated to the pore volume and average pore size of the samples, while an opposite trend was observed for FBW. The low-temperature XRD analysis confirmed the existence of non-freezable water (NFW) in coal and AC with the boundary between the freezable and non-freezable water (NFW) determined. [ABSTRACT FROM AUTHOR]

Understanding the fundamental process involved in wood sorption and wood dimensional changes is essential to improve drying and to obtain high-quality end products at a reasonable price. The main objective of this study was to examine the dimensional behaviour and the wood-water relationships of never-dried Eucalyptus saligna wood under a wide range of moisture contents below and above the fibre saturation point (FSP). Four desorption conditions from full saturated state were carried out at 21 °C in several steps until 58 % relative humidity (RH) was reached. Slower desorption rates produced higher radial, tangential, and volumetric shrinkages. The estimated collapse was also higher for milder desorption rates, being greater in the tangential direction. However, desorption rates did not change the slope of shrinkage-equilibrium moisture content (EMC) curves in the 0-58 % RH range. Further, the FSP established by extending the straight linear portion of these curves to 0 % shrinkage revealed to be not reliable for a collapse-prone species like E. saligna. Finally, shrinkage-EMC curves suggest the presence of entrapped liquid water at RH higher than about 76 %, confirming the occurrence of a region in the hygroscopic range in which the loss of bound water takes place before all liquid water has been drained. [ABSTRACT FROM AUTHOR]