Different Concentrations Of Salt Research Articles

Carbon nanotube yarns as strong flexible conductive capacitive electrodes

Carbon nanotube (CNT) yarn, consisting of 23μm diameter CNT filaments, can be used as capacitive electrodes that are long, flexible, conductive and strong, for applications in energy and electrochemical water treatment. We measure the charge storage capacity as function of salt concentration, and use Gouy–Chapman–Stern theory to describe the data. CNT yarn can also be used as conductive scaffold for the application of a porous activated carbon (AC) layer. We show the potential of CNT yarn for the generation of electrical energy from environmental entropy differences, by coating yarn (both with and without AC coating) with ion-exchange membranes (IEMs) and generating power from the salt concentration difference between river water and seawater. The use of flexible and conductive CNT yarns as capacitive electrodes and electrode scaffolds breaks with the paradigm of planar static electrodes, and opens up a range of alternative designs for electrochemical cells with enhanced performance.

TANGGAPAN ANATOMIS DARI BEBERAPA SUMBER BENIH Acacia manigum Willd. TERHADAP KONDISI CEKAMAN GARAM

Along with the increase of forest plantation development to supply raw material for industry, the utilization of marginal land with high salinity is likely to be an alternative for the plantation of A. mangium. In an effort to increase the improvement of A. mangium to be extensively planted on the widely alternative land, breeding programs were conducted to get trees of A. mangium which are tolerant to environmental stress, such as salt stress. The purpose of this study was to observe the anatomical response of A. mangium collected from several seed sources to salinity stress as a basis for salt tolerance breeding program. The trial consisted of four seed sources arranged in Completely Randomized Design with four level salt stresses(0; 22; 26 and 30 g/l) and 3 replications. The four tested seed sources are two seedling seed orchard (SSO) originated from Papua New Guinea provenance (namely group A and B), one SSO originated from Far North Queensland provenance (group C) and one SSO originated from a combining both provenances (group E). The treatment is given by watering the seedlings from each provenance with saline solution in accordance with a predetermined concentration of 200 ml per day for 4 months. The observed parameters were stomatal index, length dan width of stomata, number and diameter of trachea, and chlorophyll content. The results showed that in general the differences in salt co ncentration provided a significant effect on anatomical response of A. mangium. Except for the length of stomata, seed source variations were significantly different for all parameters. Meanwhile, seed sources x salt level interaction did not significantly affect the length and width of stomata. The higher the salt concentration, the lower the stomatal index and chlorophyll content. Conversely, the higher the salt concentration, the higher the amount of the tracheid. However the differences in salt concentration did not give a significant effect on diameter of tracheid. Overall, among the four tested seed sources, group B which is originated from Papua New Guinea provenancewas found to be the most tolerant seed sources to salt stress.

Accurate phase diagram of tetravalent DNA nanostars

We evaluate, by means of molecular dynamics simulations employing a realistic DNA coarse-grained model, the phase behaviour and the structural and dynamic properties of tetravalent DNA nanostars, i.e., nanoconstructs completely made of DNA. We find that, as the system is cooled down, tetramers undergo a gas–liquid phase separation in a region of concentrations which, if the difference in salt concentration is taken into account, is comparable with the recently measured experimental phase diagram [S. Biffi, R. Cerbino, F. Bomboi, E. M. Paraboschi, R. Asselta, F. Sciortino, and T. Bellini, Proc. Natl. Acad. Sci. U.S.A. 110, 15633 (2013)]. We also present a mean-field free energy for modelling the phase diagram based on the bonding contribution derived by Wertheim in his studies of associating liquids. Combined with mass-action law expressions appropriate for DNA binding and a numerically evaluated reference free energy, the resulting free energy qualitatively reproduces the numerical data. Finally, we report information on the nanostar structure, e.g., geometry and flexibility of the single tetramer and of the collective behaviour, providing a useful reference for future small angle scattering experiments, for all investigated temperatures and concentrations.

Non-linear Increases in Danazol Exposure with Dose in Older vs. Younger Beagle Dogs: The Potential Role of Differences in Bile Salt Concentration, Thermodynamic Activity, and Formulation Digestion

To explore the possibility that age-related changes in physiology may result in differences in drug bioavailability after oral administration of lipid based formulations of danazol. Danazol absorption from lipid formulations with increasing drug load was examined in younger (9 months) and older (8 years) beagles. Age related changes to hepatic function were assessed via changes to systemic clearance and serum bile acid concentrations. Changes to lipolytic enzyme activity and intestinal bile salt concentration were evaluated using in vitro lipolysis. Drug exposure increased linearly with dose in younger animals. In older animals, bioavailability increased with increasing dose to a tipping point, beyond which bioavailability reduced (consistent with initiation of precipitation). No differences in hepatic function were apparent across cohorts. Changes to enzyme concentrations in lipolysis studies had little impact on drug precipitation/solubilisation. In contrast, higher bile salt concentrations better supported supersaturation at higher drug loads. Differences in animal cohort can have a significant impact on drug absorption from lipid based formulation. For danazol, bioavailability was enhanced under some circumstances in older animals. In vitro experiments suggest that this was unlikely to reflect changes to metabolism or lipolysis, but might be explained by increases in luminal bile salt/phospholipid concentrations in older animals.

Improving membrane performance via bentonite polymer nanocomposite

Traditional (non-treated) sodium bentonite has been shown to exhibit substantial semipermeable membrane behavior, or the ability to restrict the migration of solutes. However, partial or complete degradation of the membrane behavior due to diffusion of invading salt cations into the sodium bentonite also has been observed. In this study, a polyacrylate modified bentonite, referred to as a bentonite polymer nanocomposite, or BPN, was evaluated as a potential substitute for sodium bentonite for the purpose of providing increased resistance to salt degradation of membrane behavior. The membrane behavior of the BPN was measured in the laboratory by establishing differences in salt concentrations ranging from 4.7 to 54mM KCl across specimens contained in either rigid-wall or flexible-wall cells under closed-system boundary conditions. The measured membrane efficiency coefficients, ω, for the BPN specimens were greater than those previously reported for specimens containing sodium bentonite under similar testing conditions. For example, the measured ω values for the BPN specimens ranged from 109% to 433% of those previously reported for the specimens containing traditional sodium bentonite, depending on the initial porosity or initial effective stress of the specimen, the concentration of KCl, and the type of test cell (rigid vs. flexible), and despite the BPN specimens not being flushed of soluble salts prior to membrane testing as in the case of the specimens containing sodium bentonite. Thus, the BPN exhibited substantially improved membrane behavior under conditions that presumably were more adverse with respect to soluble salts than those previously reported for specimens containing a sodium bentonite. However, the potential role that any excess low molecular weight polymer in the BPN may have played in affecting the results is uncertain, such that additional testing of the BPN is warranted to better understand the long-term behavior of the BPN.

Nanofluidics for Giant Power Harvesting

Nanochannels for power generation: The confinement of fluid motion in a single boron nitride nanotube can provide an efficient means of power harvesting owing to the osmotically driven streaming current under a salt concentration difference (see picture). Devices based on this principle may open a new avenue in the exploration for new sources of renewable energy.

양념 소갈비의 조리과정에서의 물리화학적 특성 평가

Marinated beef galbi is a traditional Korean dish cooked with soy sauce, pear juice, onion, sesame oil, and sugar. However, there are many differences in beef galbi, including flavor and physicochemical aspects, depending on cooking conditions. Therefore, the physicochemical characteristics of marinated beef galbi prepared through various recipes was evaluated for its effects on pH, texture, aging, proteolysis, heating conditions, cooking time, and flavor compounds (pyrazines, IMPs, or FAAs). There were significant differences in salt concentration (0.8~3.03%), pH (4.89~6.22), and solid soluble contents (1.34-6.31 Brix) between recipes in this study. In the Pearson assay for sensory evaluation, overall preference correlated well with texture (a well-known sensory attribute in meat evaluation). Controlling the pH of meat through soaking in lemon solution, alkali water, phosphate, and baking powder solution, improved water holding capacity as much as 9 to 15% compared with the control. The myofibril index (MFI) of marinated meat stored at increased 32% with 24 hours of aging and reached 39% at 48 hours of aging, and its fragmentation was observed through microscopy. SDS-PAGE showed hydrolysis of acid-soluble collagen by the pear juice, possibly related to meat tenderness. On the basis of surface temperature, the cooking time was estimated to be 8 minutes with pan heating at , 6 minutes at , and 4 minutes with charcoal at . Different pyrazine compounds, such as 2-methyl-3-phenylpyrrol(2,3-b) pyrazine (the typical product of the browning reaction) was mainly detected, and IMP (one of the main taste compounds in beef) was in higher amounts with the charcoal treatment, potentially related to its flavor preference among treatments. Our results demonstrate an effective case study and cooking system for beef galbi.

Evaluating Alfalfa (Medicago sativa L.) Cultivars for Salt Tolerance Using Laboratory, Greenhouse and Field Methods

Salinity is a limiting factor in irrigated alfalfa (Medicago sativa L.) production in many regions of the world. Objectives of this project were to evaluate twelve alfalfa cultivar responsesto salinity using laboratory, greenhouse and field experiments. The laboratory experiment evaluated plant germination under increasing levels of salt concentration (0 to 2%) and statistical differences were observed at 1.0%, 1.5% and 2.0% concentrations (10 000 ppm to 20 000 ppm). The greenhouse experiment evaluated forage production of cultivars using Salt Control Ratio (SCR) values using 3840 ppm irrigation water and significant differences were found between cultivars. The field experiment evaluated forage production under saline field conditions west of Pecos, TX (soil salinity 2131 ppm, water salinity 2950 ppm) with significant differences between cultivar yields.Canonical Correspondence Analysis (CCA), a constrained ordination technique,revealed statistical significance of canonical axes in explaining variation between alfalfa cultivars and laboratory, greenhouse and field experiments.

Consolidation enhanced membrane behavior of a geosynthetic clay liner

Semipermeable membrane behavior in clays refers to the ability of clays to restrict the migration of solutes. Thus, membrane behavior represents a potential benefit to the containment function of clay barriers used for hydraulic containment applications. In this regard, the potential influence of consolidation effective stress, σ′, on the membrane behavior of a geosynthetic clay liner (GCL) containing sodium bentonite was evaluated in the laboratory by establishing differences in salt (KCl) concentrations ranging from 3.9 to 47 mM across specimens of the GCL in a flexible-wall cell under closed-system boundary conditions. The membrane behavior exhibited by the GCL was enhanced via consolidation such that an increase in σ′ from 34.5 kPa (5 psi) to 241 kPa (35 psi) correlated with an increase in membrane efficiency from 0.015 (1.5%) to 0.784 (78.4%), respectively. The membrane efficiencies measured in this study at σ′ of 172 kPa (25 psi) and 241 kPa (35 psi) were similar to those previously reported for the same GCL using a rigid-wall cell but at unknown states of stress. The practical significance of the results is illustrated in the form of an analysis showing a reduction in liquid flux across the GCL with increasing membrane efficiency.

Transport properties of long straight nano-channels in electrolyte solutions: A systematic approach

The principle of local thermodynamic equilibrium is systematically employed for obtaining various transport properties of long straight nano-channels. The concept of virtual solution is used to describe situations of non-negligible overlap of diffuse parts of electric double layers (EDLs) in nano-channels. Generic expressions for a variety of transport properties of long straight nano-channels are obtained in terms of quasi-equilibrium distribution coefficients of ions and functionals of quasi-equilibrium distribution of electrostatic potential. Further, the Poisson-Boltzmann approach is used to specify these expressions for long straight slit-like nano-channels. In the approximation of non-overlapped diffuse parts of double electric layers in nano-channels, simple analytical expressions are obtained for the apparent electrophoretic mobilities of (trace) analytes of arbitrary charge as well as for the salt reflection coefficient (osmotic pressure), salt diffusion permeability and electro-viscosity (electrokinetic energy conversion). The approximate solutions are compared with the results of rigorous solution of non-linearized Poisson-Boltzmann equation, and the accuracy of approximation is shown to be typically excellent when the nano-channel half-height exceeds ca.3 Debye screening lengths. Due to non-negligible electrostatic adsorption of ions by nano-channels, the apparent electrophoretic mobilities of counter-ionic analytes in nano-channels are smaller than in micro-channels whereas those of co-ionic analytes are larger. This dependence on the charge is useful for the separation of analytes of close electrophoretic mobilities. The osmotic pressure is shown to be positive, negative or pass through maxima as a function of applied salt-concentration difference within a fairly narrow range of ratios of nano-channel height to the Debye screening length. The diffusion permeability of charged nano-channels to single salts is demonstrated (for the first time) to be typically larger than that of neutral nano-channels of the same dimensions due to electrical facilitation of salt diffusion.

The Effects of Short-Cycle Sprints on Power, Strength, and Salivary Hormones in Elite Rugby Players

This study examined the effects of short-cycle sprints on power, strength, and salivary hormones in elite rugby players. Thirty male rugby players performed an upper-body power and lower-body strength (UPLS) and/or a lower-body power and upper-body strength (LPUS) workout using a crossover design (sprint vs. control). A 40-second upper-body or lower-body cycle sprint was performed before the UPLS and LPUS workouts, respectively, with the control sessions performed without the sprints. Bench throw (BT) power and box squat (BS) 1 repetition maximum (1RM) strength were assessed in the UPLS workout, and squat jump (SJ) power and bench press (BP) 1RM strength were assessed in the LPUS workout. Saliva was collected across each workout and assayed for testosterone (Sal-T) and cortisol (Sal-C). The cycle sprints improved BS (2.6 ± 1.2%) and BP (2.8 ± 1.0%) 1RM but did not affect BT and SJ power. The lower-body cycle sprint produced a favorable environment for the BS by elevating Sal-T concentrations. The upper-body cycle sprint had no hormonal effect, but the workout differences (%) in Sal-T (r = -0.59) and Sal-C (r = 0.42) concentrations correlated to the BP, along with the Sal-T/C ratio (r = -0.49 to -0.66). In conclusion, the cycle sprints improved the BP and BS 1RM strength of elite rugby players but not power output in the current format. The improvements noted may be explained, in part, by the changes in absolute or relative hormone concentrations. These findings have practical implications for prescribing warm-up and training exercises.

Membrane Behavior of Compacted Clay Liners

The containment function of clay barriers used for waste containment applications (e.g., landfills) can be enhanced if such clays exhibit membrane behavior or the ability to restrict the migration of solutes (e.g., contaminants). In this regard, compacted specimens of a locally available natural clay known as Nelson Farm Clay (NFC), as well as NFC amended with 5% (dry weight) sodium bentonite, were evaluated for hydraulic conductivity, k , and the potential for membrane behavior. The membrane efficiencies of specimens of both soils compacted such that k was less than 10−7 cm/s were measured by establishing steady salt (KCl) concentration differences, −Δ Co , ranging from 3.9 to 47 mM across the specimens in a flexible-wall cell under closed-system boundary conditions. The measured membrane efficiency for the unamended NFC was negligible (i.e., ≤1.4% ), even though the k was suitably low (i.e., k< 10−7 cm/s ). In contrast, compacted specimens of the bentonite amended NFC exhibited not only lower k but al...

On the representativeness of coastal aerosol studies to open ocean studies: Mace Head – a case study

Abstract. A unique opportunity arose during the MAP project to compare open ocean aerosol measurements with those undertaken at the Mace Head Global Atmosphere Watch Station, a station used for decades for aerosol process research and long-term monitoring. The objective of the present study is to demonstrate that the key aerosol features and processes observed at Mace Head are characteristic of the open ocean, while acknowledging and allowing for spatial and temporal gradients. Measurements were conducted for a 5-week period at Mace Head and offshore, on the Research Vessel Celtic Explorer, in generally similar marine air masses, albeit not in connected-flow scenarios. The results of the study indicate, in terms of aerosol number size distribution, higher nucleation mode particle concentrations at Mace Head than offshore, pointing to a strong coastal source of new particles that is not representative of the open ocean. The Aitken mode exhibited a large degree of similarity, with no systematic differences between Mace Head and the open ocean, while the accumulation mode showed averagely 35% higher concentrations at Mace Head. The higher accumulation mode concentration can be attributed equally to cloud processing and to a coastal enhancement in concentration. Chemical analysis showed similar or even higher offshore concentrations for dominant species, such as nss-SO4-2, WSOC, WIOC and MSA. Sea salt concentration differences determined a 40% higher supermicron mass at Mace Head, although this difference can be attributed to a higher wind speed at Mace Head during the comparison period. Moreover, the relative chemical composition as a function of size illustrated remarkable similarity. While differences to varying degrees were observed between offshore and coastal measurements, no convincing evidence was found of local coastal effects, apart from nucleation mode aerosol, thus confirming the integrity of previously reported marine aerosol characterisation studies at Mace Head.

Proposing a formula for evaporation measurement from salt water resources

AbstractEvaporation involves the change in state of a liquid to a vapour. The evaporation rate from salt‐water resources depends mostly on saturated vapour pressure above its surface. On the other hand, the saturated vapour pressure is affected by the ion activity coefficient, which stems from the chemical salt concentration of water. Thus, an increase in concentration of water results in a reduction of saturated vapour pressure. In order to acquire the actual rate of evaporation from salt‐water resources, a uniform set of evaporation pans with different but specified salt concentrations were used, in a meteorological station under the same conditions. The difference in evaporation rate of each pan can only stem from the difference in chemical salt concentration and, indeed, the molar fraction of water in each saline solution. Therefore, by applying the water molar fraction in the pressure term of fresh‐water evaporation measurement formulas, these equations were developed further for determination of evaporation rate from salt‐water resources. The proposed formulas using very simple terms seem to be suitable for determination of evaporation rate from any water (typically saline, semi‐saline and fresh water) with a satisfactory precision. Copyright © 2007 John Wiley &amp; Sons, Ltd.

Swelling of compacted clay under osmotic gradients

Compacted clay liners in landfills and brine ponds are subject to chemical concentration gradients between the soil water in the clay and the reservoir solution. Soil water is the solution residing in soil pores that is chemically composed of water $(H_2O)$ molecules and dissolved salts molecules (ISSS, 1976). These differences in salt concentration generate an osmotic suction difference: osmotic suction refers to suction arising from the presence of dissolved salts in water (Lu & Likos, 2004). This suction difference is dissipated through the diffusion of salts and flow of H2O molecules (Barbour & Fredlund, 1989). Changes in the dissolved salts concentration of soil water from salt diffusion in response to osmotic suction difference will alter the swell magnitudes of expansive clays, which are strongly influenced by salt concentration (Bolt, 1956; Mesri & Olsen, 1971; Yong & Warkentin, 1975; Mitchell, 1993). Osmotic suction differences between soil water and reservoir solution may thus alter the wetting-induced volume change behaviour of compacted clays used as liners in landfills and brine impoundments.

The effect of membrane potential on the development of chemical osmotic pressure in compacted clay

When clay soils are subjected to salt concentration gradients, various interrelated processes come into play. It is known that chemical osmosis induces a water flow and that a membrane potential difference develops that counteracts diffusive flow of solutes and osmotic flow of water. In this paper, we present the results of experiments on the influence of membrane potential on chemical osmotic flow and diffusion of solutes and we show how we are able to derive the membrane potential value from theory. Moreover, the simultaneous development of water pressure, salt concentration and membrane potential difference are simulated using a model for combined chemico-electroosmosis in clays. A new method for short-circuiting the clay sample is employed to assess the influence of electrical effects on flow of water and transport of solutes.

Effect of temperature on dissolution of Turkish trona

In this study, the rate of dissolution of Turkish trona was measured as a function of the trona brine concentration and temperature. The results were compared with a theoretical model of the rate of dissolution from a vertical wall under conditions of natural convection driven by the density gradient in the boundary layer caused by salt concentration differences. The average rate of dissolution in water was measured to be 2.8 g/m 2 s. It was found that the temperature is apparently a more important factor at low solution concentrations than at high concentrations.

Countercurrent transport of organic and water molecules through thin film composite membranes in aqueous–aqueous extractive membrane processes. Part I: experimental characterisation

This paper presents an experimental study on organic and water mass transfer through thin film composite (TFC) membranes, made of a 2 μm thick polydimethylsiloxane (PDMS) layer coated onto a microporous support of polyethersulfone. These were used for the extraction of various organic molecules from aqueous solutions with different ionic strengths. Independent measurements of organic and water transfer rates were performed using lab-scale single- and multi-tube mass exchangers. The rate of organic transfer across TFC membranes is shown to be independent of the affinity of the organic molecules for the PDMS layer, owing to negligible mass transfer resistance in this thin layer. As a consequence, the overall mass transfer coefficient measured for aqueous–aqueous extraction of hydrophilic compounds (i.e. with low affinity for PDMS) was up to one order of magnitude larger for TFC membranes than for 350 μm thick PDMS membranes operated under the same hydrodynamic conditions. The effect of osmotic pressure on water transport through TFC membranes was assessed by liquid–liquid extraction experiments using saline solutions. Water flux increases with increasing difference in salt concentration across the membrane, due to increased activity gradient. For the range of salt concentration and PDMS layer thickness used in this work, the osmotic water flux across the membrane has only a marginal effect on the rate of organic extraction. On the other hand, the ionic strength of feed and extractive phases has a direct influence on the organic transfer, due to the dependence of transport and equilibrium properties (i.e. diffusion and partition coefficients) on salt concentration. As a result, TFC membranes exhibit an asymmetric behaviour depending on operating mode. For the same hydrodynamic conditions and ionic strength, organic flux is higher when a saline solution is on the coated side than when it is on the porous side of the membrane. This has obvious implications in the design and operation of TFC membrane processes for the extraction of organics from saline solutions.

Transport of Water and Ions Through a Clay Membrane

A model for hindered transport of water and ions is used to predict transient flow through a clay membrane caused by an initial difference in the concentration of salt solutions in reservoirs on the two sides of the membrane. Transport is assumed to be controlled by three coefficients, which are analogous to the permeability, salt diffusivity, and salt reflection coefficient of the membrane. Initial fluid motion is caused by osmosis, leading to a buildup of pressure on one side of the membrane. However, the clay forms an imperfect ion exclusion membrane and the final steady state is one of equal concentrations and pressures on the two sides of the membrane. The time-dependent differences in pressure and salt concentration across the membrane are predicted to vary as the sum of two decaying exponentials. When the salt reflection coefficient is small, one time scale governs Darcy flow through the membrane and another the diffusion of salt. Experimental results confirm the analysis. Although the salt concentration in the reservoirs was monitored in the experiments, estimates of the transport coefficients can be obtained by measuring only the pressure change across the membrane.

Determination of the chemical speciation of trace metals in aqueous systems by the Wageningen Donnan Membrane Technique

In order to determine the ‘free’ metal ion concentration in aqueous solutions the so-called Wageningen Donnan Membrane Technique (WDMT) has been developed. This involves a continuous flow system in which the donor side and the acceptor side of the WDMT cell are continuously flushed with solution across the membrane. The new cell design allows pseudo equilibrium to be reached for the free metal ions via a Donnan equilibrium across a negatively charged ion-exchange membrane within a reasonable time span. The donor solution contains both ‘free’ and complexed metal ions. The concentration of the cations in the acceptor solution is either equal to the concentration of the ‘free’ cation concentration in the donor solution, or it can be calculated using simple correction factors. The optimization experiments have been performed with cadmium and copper, in the presence of various (in)organic complexing agents, at various pH values, and different salt concentrations. In multi-component systems, like the systems used for the experiments with calcium, cadmium, copper, protons and EDTA, the results are in good agreement with the speciation calculations. The transport of the different cations and anions across the membrane can be very well explained by the simplified theory presented. Effects of difference in salt concentration on metal concentrations can be corrected. For the more complicated systems with natural dissolved organic matter (e.g. humic acid) the concentrations measured in the acceptor solution are also in good agreement with the speciation calculations performed for the donor solution.