KC1 Solution Research Articles

Counterbalanced Valve Metal Oxide as a Reliable Dielectric Layer for Electrowetting-on-dielectric Devices

Author(s): Chen, S; Kim, CJCJ | Abstract: Valve metal oxide (anodized oxide) is used in a mirrored configuration to serve as self-limiting dielectric layers of electrowetting-on-dielectric (EWOD) devices. Resembling nonpolar electrolytic capacitors, the two opposing metal-dielectric layers always counterbalance each other so that voltages of any polarity can be applied without current flow. By using tantalum pentoxide as the valve metal oxide for experimental evaluation, the mirrored configuration is compared with the usual configuration and further compared with silicon oxide and silicon nitride, which are two dielectric materials commonly used for EWOD. Experiments with a range of applied biases confirm that in a mirrored configuration, one of the two metal-dielectric-electrolyte combinations is always reverse-biased to prevent the current leakage, which is the most common mode of failure for the EWOD devices. The utility is demonstrated by manipulating droplets of KC1 solution on both the parallel-plate and one-plate EWOD devices.

Kinetics of nitrogen mineralization in sewage amended soil

A laboratory experiment was carried out at, Jaunpur (25°18’ N, 83°03’ S) to study the kinetics of N mineralization in sewage amended soils. Four different agricultural fields viz., A, B, C and D which has been receiving sewage for irrigation since last five or more years were selected for study. The three replicate of each treatment were incubated at room temperature (25°C) for 7 weeks. The soils were brought to field capacity by addition of distilled water. The subsamples (10g) were withdrawn from each sample after every week interval and extracted immediately with 100 ml of 2 M KC1 solution and N was determined. The fitness of the model for mineralization study was tested by least square method and the mineralization rate constant (K) and half-life (t1/2) were calculated from fitted model. It was observed that, the highest mineralized N (121.20 mg/kg) was observed in soil receiving sewage continuously while lowest in N mineralized 112.80 mg/kg was observed in soil receiving less amount of sewage. Estimated mineralization rate content ‘K’ in four soils was 0.44, 0.38, 0.10 and 0.43 and correlation coefficient were 0.99, 0.98, 0.99 and 0.99, respectively. The study revealed that, nitrogen mineralization was increased with increasing period of incubation with rapid increase during 2–4 weeks of incubation. First order model of kinetics was best suited for nitrogen mineralization in sewage amended soil under study.

Diffusion in the Diaphragm Cell: Continuous Monitoring of the Concentrations and Determination of the Differential Diffusion Coefficient

We present a method to monitor continuously the electrical conductivity of the solutions in both compartments of a diaphragm cell in which diffusion is occurring. This allows a much smaller initial concentration difference to be applied across the diaphragm rather than the usual larger initial concentration difference. Together with an improved filling procedure and a more reproducible stirring device, these improvements lead to the determination of differential diffusion coefficients with accuracies comparable to those of the precise optical interferometric methods. This is shown for aqueous solutions of NaCl, KC1, Na2SO4, and MgSO4 at 25 °C. By using aqueous solutions of HC1, the H+-exchange properties of the diaphragm and its influence on the measurements become detectable.

The Microscopic Mechanism of Compton Scattering of Some Saline Solutions

Based on preliminary research results about Compton scattering of saline solution, a linear relationship between the scattered photon counts and the concentrations had been deduced for a certain solution and it had been found that the slope of the lines was decreasing with the atomic number of the cation increasing for LiC1, NaCl and KC1(the same result for MgC1BB2BB and BaC1BB2BB) solution. Now, in order to explain such rule of the slope, the microscopic mechanism of scatterers has been studied. Through the electronic structure of hydrated ions is analyzed in detail: the distance between hydration ion and O atom after optimized, the total energy of hydration ion, the equivalent charge distribution of hydration ion and the electronic density distribution of hydration ion. At last, it is concluded that the reason of the slope decreasing when the atomic number of the alkali cation for KC1, NaCl, LiCl solutions (or MgC1BB2BB and BaClBB2BB solutions) is the bounding strength of the system on its electrons become increasing, the probability of Compton scattering is decreasing, and it will constrain the increasing velocity of the scattered photon counts.

Molecularly imprinted polymer with assistant recognition polymer chains for bovine serum albumin

A new protein molecularly imprinted polymer (MIP) was prepared with grafting polyvinyl alcohol as assistant recognition polymer chains (ARPCs). The ARPCs and acrylamide monomers were interpenetrated and then polymerized on the surface of macroporous acrylate adsorbent spheres. The template BSA was removed by treatment with 2.00 mol•L −1 potassium chloride (KCl) solution and the adsorbed proteins were detected with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). 0.150 mol•L −1 , 0.500 mol•L −1 , and 2.00 mol•L −1 KCl solutions were used as eluent to wash the adsorbed proteins. The SDS-PAGE results show that proteins washed out with 2.00 mol•L −1 KCl solution were from nonspecific adsorption of macroporous acrylate adsorbent spheres, and proteins washed out with 0.500 mol•L −1 KC1 solution were specific proteins imprinted by MIP resins. MIP resins with ARPCs had better recognition to the target proteins than that without ARPCs. The adsorption capacity of MIP resins immobilized ARPCs to the template BSA was about 80-100μg•g −1 when it was used for the adsorption of proteins mixture, and the specific adsorption of the target protein was obviously increased.

Horizontally Aligned Single Array of Co Nanowires Fabricated in One-Dimensional Nanopore Array Template

A one-dimensional (1-D) anodic aluminum oxide (AAO) pore array horizontally aligned on a Si(100) substrate with a pore diameter of 50 nm was fabricated using optimized anodization parameters. The oxide barrier layer at the pore base was removed in a diluted KC1 solution, which was negatively biased at 2.5-5 V. A single array of cobalt nanowires horizontally aligned on the substrate was successfully electrodeposited inside the pores of the 1-D AAO pore array template. The Co nanowire array was clearly observed by scanning electron microscopy, and magnetic hysteresis curves of the samples were measured before and after cobalt deposition.

Formation of inositol hexaphosphate monolayers at the copper surface from a Na-salt of phytic acid solution studied by in situ surface enhanced Raman scattering spectroscopy, Raman mapping and polarization measurement

Inositol hexaphosphate (IP 6) was proposed as an environmentally friendly reagent to prevent metal surface from corrosion through a self-assembled monolayers (SAMs) method. In situ surface enhanced Raman scattering (SERS) spectroscopic investigations revealed that the self-assembling of IP 6 at the roughened copper surface in a Na-salt phytic acid solution took two steps involving firstly self-cleaning the surface and then forming IP 6 monolayers. The features of the IP 6 monolayers were evaluated by the time-dependent Raman spectroscopic measurement, Raman mapping and electrochemical polarization experiments. Based on the calculation results for vibration spectrum of IP 6 molecule with PM3 method, a model for IP 6 molecule adsorbed chemically on the roughened copper via two co-planar phosphate moieties was suggested. The copper surface with the IP 6 monolayers presents the inhibiting action in a 0.1 mol L −1 KC1 solution but the relative inhibition efficiency is of 41.2% because of the water co-adsorption.

Electrowetting Measurements with Mercury Showing Mercury/Mica Interfacial Energy Depends on Charging

We demonstrate that the interfacial energy between mercury and mica is a function of charge on the mercury surface, decreasing with increasing positive charge. The contact angle of mercury on mica has been measured as a function of potential applied to the mercury, which forms the working electrode of a cell containing either KC1 or NaF electrolyte solution. At high negative applied potentials, a stable aqueous film exists between the mercury and mica surface. As potential is made less negative, the film collapses and mercury partial1 wets the mica at a critical potential, close to the electrocapillary maximum. Upon increasing the potential further (making the Hg surface more and more positive), the contact angle measured within the mercury continually decreases. Electrowetting with mercury is not unexpected since its interfacial tension with the aqueous phase is known to be a function of applied potential. However, the observed decrease goes against the trend expected from the Young equation if only this effect is considered. To explain the data we must allow the mercury/mica interfacial tension also to vary with applied potential. This variation indicates that the mercury surface is positively charged by contact with mica, consistent with known contact electrification between these two materials. The inherent charges at the mercury interfaces with mica and electrolyte solution result in contact angle changes of some tens of degrees with a change in applied potential of half a volt orders of magnitude less than the potentials required to effect comparable changes in other electrowetting systems.

Influence of exogenously supplied KCl on water binding mode of durum wheat leaf segments

Durum wheat leaf segments (Triticum durum Desf.) were incubated in solutions of KC1 to test the effect of selective accumulation of ions, on tissues affinity for water. This was estimated trough an indirect estimate of the average enthalpy of water sorption. Leaf segments were collected from well watered plants grown in a controlled environment and were incubated in different KC1 solutions. As increasing concentrations of KC1 were included in the medium accumulation of K + and Cl - ions and changes in the water-binding mode of the leaf segments were observed. Large increases in tissue affinity for water appeared when KC1 concentrations in the medium were between 20-30mM and 50mM. These findings were repeatable in leaf segments of plants that differed in both growth stage and genotype. Relationships between tissue affinity for water and tissue K + and Cl - content were examined. Tissue affinity for water did not change until the concentration of K + in the leaf tissues reached approximately 50-55 mg/g dry weight, where large increase in strength of water binding was observed. Above this threshold tissue affinity for water was low even if K + content increased.

Effect of seed priming and rate on direct-seeded,. rainfed summer rice (Oryza sativa)

Rainfed summer rice (Oryza sativa L.) panicle number and filled grainslpanicle, suffers from frequent drought conditions, re-. and better N, P and K uptake and water-use sulting in very low and fluctuating yield. efficiency, thereby giving significantly Seed priming induces drought tolerance to higher yield than the other treatments the crop. In view of this, a field experiment (Tables 1, 2). Similar observations were was conducted to study the effect of potas- made by Peeran and Natanasabapathy sium as priming material on the plant- (1 980) and Borgohain (1988). However, water-relationship and ultimately on yield of grain yield was significantly higher when direct-seeded summer rice and also to find the seed rate was 70 kglha. The lower was out an optimum seeding rate of primed seed. the seed rate the higher was the number of The study was carried out at Jorhat during grainslpanicle, 1,000-grain weight and wa- summer 1989 in a randomized block design. ter-use efficiency (Table 1). Interaction of The soil was sandy loam with pH 5.25 (1 : seed priming and seed rate on grain yield 2), organic carbon 0.935% and available N, 2720, 0.25 and 1556 kfla re- TaM 1. Grain yield (@a) of IR 50 rice as affected 4 spectively. the interaction between seed priming and seed The treatments consisted of- seed priming . rate with KC1 solution @ 0,3,4,5 and 6% along - with the normal practice of dry seeding and Seed Seed rate (kglha) 3 seed rates of IR 50 (70, 85 and 100 kg/ priming ha). The seeds were air-dried under shade 7O 85 100 Mean after priming to bring the moisture content Dry seeding 7.82 9.09 9.25 8.72 to normal before sowing. The seeds were 0% 10.81 8.49 8.44 9.25 sown in lines 25 cm apart on 25 March 1989 3% 11.08 10.67 10.35 10.70 and the crop matured in 118 days. Fertiliz- 4% 13.75 11.58 11.36 12.23 ers were applied @ 40, 20 and 20 kg N, 5% 12.75 11.40 11.13 11.76 P20, and K20ha respectively. The con- 6% 12.03 9.97 10.95 10.98 sumptive use of water in the crop was esti- Mean 11.37 10.20 10.24 mated by using the soil-m~isture~depletion method and the water-use efficiency by di- = CD (P 0.05) viding the grain yield with consumptive use. Seed priming 0.46 Seed priming with 4% KC1 resulted in Seed rate 0.33 the significantly highest plant population, !nteraction 0.80

Cell Viability of Japanese Radish Cylinders Immersed in Hypertonic Solutions

To determine the effect of immersion time and osmolality of solution on cell viability, the triphenyl tetrazolium chloride test was performed using cylindrically-shaped Japanese radish after immersion in several hypertonic solutions (NaCl, KC1, NaNO3 and CaCl2 solutions at 20°C). There was a significant decrease in cell viability with immersion time. The immersion time at which cell viability decreased to 50% (CT50) was calculated using an empirical equation. It was indicated that increase of osmolality resulted in a decrease of the CT50.

The ion-specific behavior of watertree growth in LDPE

The growth of water trees in low-density polyethylene (PE) has been studied. Trees were grown in solutions containing a fixed anion, Cl/sup -/, but different cations with valences of +1 (Li/sup +/), +2 (Mn/sup 2+/) and +3 (Fe/sup 3+/). An ion-specific effect on tree growth and tree appearance has been found. Generally, these results have been shown to be correlated with either the ion-water interactions or the interionic attractions. However, for the specific case of adding small amounts of 3+ cations into univalent ion solutions, such a correlation was not found: it is likely that the hydrogen ions, introduced by the multivalent ions through their electrostatic interaction with water molecules, play an important role. The abnormal transport behavior of such hydrogen ions in the solution and probably in the polymer, may expand the overall region affected by treeing but reduce the visibility of the individual trees themselves. A similar process may account for the particularly translucent appearance of trees formed with pure FeCl/sub 3/ solutions. This argument is further demonstrated through tree growth experiments using KCl solution and its mixtures with small amounts of HCl. It was found that this additive accelerated tree growth. It is argued that small amounts of KOH might be expected to show an effect similar to HCl because of the similar transport behavior of OH/sup -/ ions and H/sup +/ ions respectively and such enhanced tree growth was demonstrated, using small quantities of KOH added to KC1 solutions.

Application of a Cylic Polyamine Ionophore in Phosphate Selective Electrodes for Environmental Analysis

The application of macro- and micro-electrodes constructed using the new ionophore were tested in a range of solution compositions reflecting concentrations found in fresh waters, and containing Cl−, NO3 −, SO4 2-, HCO3 2-, H4SiO4 and a natural humic acid. The inhibition of the electrode responses to these ions was quantified using a mixed-solution method by optimising the agreement between the measured potentials and predictions from the Nicolsky-Eisenman equation. In addition, measurements were made in separate solutions of KC1 to enable results to be compared with the literature. Apart from the results obtained for humic acid, mean selectivity coefficients for 16 macro- and 21 micro-electrode experiments are given. The results indicate inhibition of the electrode response to phosphate for all the anions in the concentration ranges of 0.05–1 mM Cl−, 0.1–1.0 mM NO3 −, 0.1–10.0 mM HCO3 − and 0.1–1.5 mM SO4 2- with high selectivity for HPO4 2- in the presence of both dissolved silicon and a standard humic acid. This means that the application of the electrodes to hard waters is impracticable although studies of soft waters and laboratory studies in controlled conditions, e.g. calcium phosphate precipitation experiments, are feasible.

Reversibility and linearity of sorption for some cations onto a Bulguksa granite

Sorption experiments for60Co,85Sr, andl37Cs onto a Bulguksa granite were carried out to investigate the migration mobility. Reversibility and linearity of sorption as well as sorption mechanism were examined. Sorption isotherms were fitted in the range of 10-3 M and 10-11 M and the applicability of the two isotherm equations, Langmuir and Freundlich, was examined.85Sr give rise to almost linear isotherms, while60Co and137Cs show non-linear behavior. In order to distinguish sorption types of the cations, a sequential chemical extraction was introduced. The sorbed cations were extracted by applying different solutions of synthetic groundwater CaCl2, KC1, and KTOX(K2C2O4+NH2OH-HC1). Sorption types considered are reversible sorption under a groundwater condition, ion exchange, association with ferro-manganese oxides, and irreversible fixation.

Nutrient conductivity effects on sweet pepper plants grown using a nutrient film technique

Sweet pepper (Capsicum annuum L.) plants were grown using Nutrient Film Technique (NFT) at electrical conductivity (EC) levels of 2 ,4, 6, 8, and 10 mS cm‐1. Higher EC levels were achieved by adding concentrated KC1 solution to the basic nutrient solution maintained at EC 2 mS cm‐1. An additional treatment of high Ca with EC 10 mS cm‐1 was made up of a solution of KC1 and CaCl2 at a ratio of 3:1 (w/w). High nutrient conductivities resulted in high blossom‐end rot (BER) incidence. This was related to the suppression of Ca uptake and reduced accumulation in the fruit accompanied by an increase in the accumulation of Mg and particularly K. Extra Ca at the highest EC level promoted the accumulation of Ca by the fruit and reduced the incidence of BER. The reduction of Ca uptake in the fruit at higher EC was more pronounced at the blossom‐end of the fruit. Fractionation of Ca compounds revealed that higher EC levels reduced the physiologically active acetic acid soluble component, particularly during the BER sensitive rapid fruit growth stage.

Inhibition of quantal release from motor nerve by wortmannin.

1. The effects of wortmannin, an inhibitor of phosphatidylinositol (PI) kinases and myosin light chain kinase, on the quantal release of neurotransmitter from mouse phrenic nerve were investigated. 2. Wortmannin (10 - 100 microM) initially enhanced, thereafter progressively depressed spontaneous quantal discharge (miniature endplate potential, mepp). The mean amplitude and the amplitude distribution of mepp were not altered. 3. The compound inhibited and prevented the intensive quantal release evoked by high KC1 solution as well as the mepp burst induced by alpha-latrotoxin, a polypeptide toxin that possesses Ca2+-independent synaptic action to trigger quantal release. The inhibitory actions of wortmannin were partially reversible. 4. Wortmannin depressed the amplitude of endplate potentials (epps) and increased the coefficient of variance of epps. The profile of epps in response to high frequency nerve stimulation exhibited fluctuations between run-down and run-up. The phenomenon is thus different from the consistency of run-up characteristic as the motor nerve Ca2+ channel is blocked by omega-agatoxin IVA. 5. LY294002, another inhibitor of PI 3-kinase, raised mepp frequency without causing late phase suppressions. The compound did not inhibit KC1-, alpha-latrotoxin- or nerve stimulation-evoked quantal release. 6. The results suggest that wortmannin could depress quantal release beyond the step of Ca2+ channel blockade, probably by interfering with the exocytotic cascade.

Nutrient conductivity effects on sweet pepper plants grown using a nutrient film technique

Sweet pepper (Capsicum annuum L.) plants were grown using Nutrient Film Technique (NFT) system with a nutrient solution of electrical conductivity (EC) 2 mS cm‐1. Higher conductivity levels of 4, 6, 8, and 10 mS cm‐1 were achieved by adding concentrated KC1 solution to the basic nutrient solution. Higher ionic strength of the nutrient solution resulted in smaller sized fruit, reduced fruit dry weights, and decreased vegetative growth in terms of lower leaf area and specific leaf area (SLA). It also encouraged accumulation of more assimilates in shoots than fruits, decreased plant water consumption, leaf ψ, and fruit firmness. It increased leaf sto‐matal resistance, fruit dry matter content, fruit respiration and ethylene production, and advanced fruit colour change.

PRINTED CIRCUIT BOARD TIME DOMAIN REFLECTOMETRY PROBE: MEASUREMENTS OF SOIL WATER CONTENT

Time domain reflectometry (TDR) is a widely used, nondestructive measurement technique for determining soil-water content (θ) and bulk soil electrical conductivity. Until recently, small scale applications of TDR have been restricted because of the lack of small-scale, high-resolution TDR probes. As a result of the introduction of the TDR coil probe principle (Nissen et al. 1998b) and, in this study, the printed circuit board TDR probe (PCBP), the lower limit of the measurement scale for TDR is changing. The travel time of the electromagnetic waves in the PCBP was prolonged by forcing the electromagnetic waves to travel in a three-rod serpentine waveguide produced in the copper cladding of a circuit laminate (50 mm long, 10 mm width, 0.64 to 1.00 mm thickness). The apparent relative dielectric permittivity (K a ) measured by the PCBP (K a, PCBP ) was calibrated against K a measured by a standard two-rod TDR probe in air and six fluids of various K a . A two-phase dielectric mixing model was used to describe the contributions of the circuit laminate and the surrounding media to K a , PCBP . Eleven PCBPs were produced on four different types of circuit laminate with well known water absorption properties. Minor changes in K a attributable to water absorption could be observed for some of the circuit laminates. However, all four circuit laminates showed equal measurement performance during water infiltration in an initially air-dried soil. None of the circuit laminates was damaged by the soil environment during the water transport experiments. The waveguide of the PCBP is in direct contact with the soil, which should enable the PCBP to also measure electrical conductivity (EC). A calibration experiment was carried out where the load resistance (R 1 ) and the EC were measured in deionized water and six KC1 solutions by the PCBPs and a conductivity meter, respectively. A simple linear relationship was found between RL and EC. Therefore, in contrast to the TDR coil probe, the PCBP seems promising for obtaining simultaneous, small-scale and high-resolution TDR measurements of water and solute transport.

Renal tubular secretion of potassium in the normal dog.

Journal of the American Society of Nephrology : JASN 9(7):p 1341-1344, July 1998. | DOI: 10.1681/ASN.V971341

Viability and function of human sperm in electrolyte-free cold preservation

Objective: To assess the viability and function of human sperm in electrolyte-free cold preservation. Design: Prospective comparative study. Setting: Andrology laboratory of out hospital. Patient(s): Ten semen samples obtained from patients attending our infertility clinic. Intervention(s): Ejaculated sperm were washed using the electrolyte-free Percoll gradient and were then preserved in 0.33 M glucose solution, 0.16 M NaCl solution, 0.16 M KC1 solution at 4°C for 4 weeks. As a control, TEST (TES and Tris) yolk buffer (TYB) was added to the ejaculated semen and preserved at 4°C. Main Outcome Measure(s): Sperm tail morphology, motility, viability (eosin-Y stain), and the concentration of adenosine triphosphate (ATP) were analyzed. Result(s): The number of sperm with normal tail form and the motility of sperm preserved in glucose solution (electrolyte-free cold preservation) were significantly ( P < 0.01) higher for 4 weeks than those of sperm preserved in the other three media. The sperm viability in glucose solution was 75.5%, 65.4%, and 51.3%, after 1, 2, and 4 weeks, respectively. The ATP concentration after 1, 2, and 4 weeks remained 64.2%, 53.0%, and 4.3% of the prestorage value, respectively, in the sperm stored in glucose solution. Conclusion(s): The morphology, motility, viability, and ATP concentration of sperm in electrolyte-free cold preservation were substantially better than those in NaCl solution, KCl solution, or TYB for 2 weeks.