Presence Of Nal Research Articles

Oxidation of D-Glucose and D-Fructose by N-Bromosaccharin in Aqueous Acetic Acid Medium in Presence of NaLS: A Comparative Study

The oxidation of D-Glucose and D-Fructose was monitored iodometrically by N-Bromosaccharin in the aqueous acetic acid medium in presence of NaLS (Sodium Lauryl Sulphate). Reaction demonstrated that oxidative species HOBr and H2O⊕Br were involved in the acidic oxidation of Carbohydrates. It was established that respective acids of carbohydrates gluconic acid and arabinoic acid were the oxidation products. Respective acids of carbohydrates were the results of reactive HOBr in acidic conditions. The reaction follows first-order kinetics with respect to HOBr, Glucose, Fructose, and [H+] uniformly and is homogeneous. The Effect of varying salt electrolyte concentration was insignificant showing that the molecular species was involved in the rate-determining step. The Reaction was monitored at 600C (±10C) temperature and thermodynamic activation parameters were determined. Binding parameters have been calculated by analyzing the data using the model suggested by Menger Portnoy and Piszkiwicz's model. Kinetic studies, stoichiometry of the reaction and product analysis have been proposed for the oxidation of sugars in the presence of NaLS.

Acoustically Forced Droplet Combustion of Liquid Fuel with Reactive Aluminum Nanoparticulates

ABSTRACTThis experimental study explores the effects of acoustic excitation on burning droplets of liquid ethanol loaded with reactive aluminum nanoparticles (nAl). Continuously fed fuel droplet combustion and flame extinction (blowout) experiments were conducted in the vicinity of a pressure node (or velocity antinode) created in a closed acoustic waveguide, with a range of applied resonant forcing frequencies, pressure or velocity perturbation amplitudes, and particle loading concentrations. Simultaneous phase-locked OH* chemiluminescence and visible images were taken to quantify the influence of nanoparticle concentration on burning rate constant (K) and flame-acoustic coupling dynamics. In the presence of velocity perturbations, nAl-laden droplets were observed to burn for longer periods of time than they burned in the absence of acoustics, likely resulting from suppression of particle agglomerate formation and expulsion. It was found that at higher forcing frequencies, there were relatively greater enhancements in K values of nAl-loaded droplets than for lower frequencies. Interestingly, while at higher forcing amplitudes, the burning rate constant increased for a given loading concentration, that increase tended to be reduced at higher loading concentrations. Phase-locked imaging demonstrated that the presence of nAl increased the Rayleigh index (G) as compared with neat fuels under the same forcing conditions. Higher amplitude excitation leading to extinction showed that the addition of nAl could significantly increase the mean extinction strain rate, in some cases by up to 44%.

Influence of nalidixic acid on tandem heterotrophic-autotrophic kinetics in a “NIPHO” activated sludge reactor

This work analyzes the effect of nalidixic acid (NAL) on the kinetics of the heterotrophic and autotrophic biomass growth within a “NIPHO” activated sludge reactor treating municipal wastewater. Thus, the effect of this chemical in the degradation rates of carbon and nitrogen sources and net biomass growth rate is evaluated. Activated sludge samples were taken at three different operation conditions, changing the values of hydraulic retention time (2.8–3.8 h), biomass concentration (1400–1700 mgVSS L−1), temperature (12.6–14.8 °C), and sludge retention time (11.0–12.6 day). A respirometric method was applied to model the kinetic performance of heterotrophic and autotrophic biomass in absence and presence of NAL, and a multivariable statistical analysis was carried out to characterize the influence of the operation variables on the kinetic response of the system, which was finally optimized. The results showed that there was no inhibitory effect of NAL on heterotrophic biomass, with an increase of net heterotrophic biomass growth rate from 1.70 to 6.73 mgVSS L−1 h−1 at the most favorable period. By contrast, the autotrophic biomass was negatively affected by NAL, reducing the value of net autotrophic biomass growth rate from 25.37 to 10.29 mgVSS L−1 h−1 at the best operation conditions. In general, biomass concentration and temperature had the highest influence on the degradation rate of carbon and nitrogen sources, whereas hydraulic retention time and sludge retention time were the most influential on net heterotrophic and autotrophic biomass growth rates.

Effects of inorganic nanoparticles on viability and catabolic activities of Agrobacterium sp. PH-08 during biodegradation of dibenzofuran.

This study investigated the cytotoxicity, genotoxicity, and growth inhibition effects of four different inorganic nanoparticles (NPs) such as aluminum (nAl), iron (nFe), nickel (nNi), and zinc (nZn) on a dibenzofuran (DF) degrading bacterium Agrobacterium sp. PH-08. NP (0-1,000 mg L(-1)) -treated bacterial cells were assessed for cytotoxicity, genotoxicity, growth and biodegradation activities at biochemical and molecular levels. In an aqueous system, the bacterial cells treated with nAl, nZn and nNi at 500 mg L(-1) showed significant reduction in cell viability (30-93.6 %, p < 0.05), while nFe had no significant inhibition on bacterial cell viability. In the presence of nAl, nZn and nNi, the cells exhibited elevated levels of reactive oxygen species (ROS), DNA damage and cell death. Furthermore, NP exposure showed significant (p < 0.05) impairment in DF and catechol biodegradation activities. The reduction in DF biodegradation was ranged about 71.7-91.6 % with single NPs treatments while reached up to 96.3 % with a mixture of NPs. Molecular and biochemical investigations also clearly revealed that NP exposure drastically affected the catechol-2,3-dioxygenase activities and its gene (c23o) expression. However, no significant inhibition was observed in nFe treatment. The bacterial extracellular polymeric materials and by-products from DF degradation can be assumed as key factors in diminishing the toxic effects of NPs, especially for nFe. This study clearly demonstrates the impact of single and mixed NPs on the microbial catabolism of xenobiotic-degrading bacteria at biochemical and molecular levels. This is the first study on estimating the impact of mixed NPs on microbial biodegradation.

Morphine Reduces the Threshold of Remote Ischemic Preconditioning Against Myocardial Ischemia and Reperfusion Injury in Rats: The Role of Opioid Receptors

Opioid receptors mediate the cardioprotection of remote ischemic preconditioning (RIPC). The authors tested the hypothesis that morphine reduces the threshold of cardioprotection produced by RIPC. A randomized, prospective study. A university research laboratory. Forty-five male Sprague-Dawley rats. Anesthetized, open-chest, male Sprague-Dawley rats were assigned randomly to 1 of 7 treatment groups. RIPC1 and RIPC3 were, respectively, induced by 1 or 3 cycles of 5 minutes of femoral artery ischemia interspersed with 5 minutes of reperfusion. Morphine (MOR, 0.1 mg/kg) and the opioid receptor antagonist naloxone (NAL, 6 mg/kg) were administered 30 minutes before sustaining ischemia. MOR + RIPC1 and NAL + MOR + RIPC1 groups received the combination of MOR and RIPC1 in the absence or presence of NAL before coronary artery occlusion. Ischemia and reperfusion injury then were induced by 30 minutes of left coronary artery occlusion followed by 120 minutes of reperfusion. Infarct size, as a percentage of the area at risk, was determined by 2,3,5-triphenyltetrazolium staining. RIPC3 and the combination of MOR and RIPC1 groups significantly reduced the infarct size compared with the control group. RIPC1, MOR, and NAL did not affect infarct size. NAL pretreatment reversed cardioprotection of the combination of MOR and RIPC1 treatments. MOR reduces the threshold of RIPC, and opioid receptors mediate this augmentative effect.

Photogalvanic solar energy conversion: Study with photosensitizers Toluidine Blue and Malachite Green in presence of NaLS

The photogalvanic effect of photosensitizer – reductant pair, Toluidine Blue–Arabinose and Malachite Green–Arabinose have been studied in presence of anionic surfactant NaLS (sodium lauryl sulphate) and a tentative mechanism has been proposed for the cell reaction. The photopotential (Δ V) and photocurrent ( i sc) were obtained 813.0 mV and 60.0 μA in Toluidine Blue system and 348.0 mV and 36.0 μA in Malachite Green system. The conversion efficiency and storage capacity of the developed cells were found to be 0.1448% and 123.0 min, respectively with Toluidine Blue system and 0.0590% and 32.0 min, respectively with Malachite Green system.

An efficient synthesis of 5‐benzoyloxazolines by regio‐ and stereo‐controlled reaction of N‐substituted 2‐benzoylaziridines under microwave irradiation

Abstractmagnified imageSeveral N‐acyl‐2‐benzoylaziridines were prepared conveniently in good to high yields (71‐93%) and used in the preparation of 5‐benzoyloxazolines (76‐91%) by a regio‐ and stereo‐controlled reaction in the presence of Nal as an efficient catalyst under microwave irradiation in short reaction times (5‐10 mins). The structure of the regioisomeric product was confirmed by X‐ray analysis.

Roughness development in electrodeposited soft magnetic CoNiFe films in the presence of organic additives

The effects of three additives, sodium lauryl sulfate (NaLS), saccharin (Sacc), and NaLS + Sacc, on roughness development during the electrodeposition of CoNiFe films were investigated. The characterization of these films by atomic force microscopy shows that the electrodeposits produced from NaLS containing solution result in a rough surface. The role of NaLS surfactant is to change the interfacial tension and clean non-polar species like hydrogen bubbles from the surface. In Sacc containing solution the evolution of a smooth surface is controlled by adsorbed Sacc molecule at the interface. The kinetic roughening of these deposits was investigated by dynamic scaling analysis. It was demonstrated that the roughness of CoNiFe films, obtained in the presence of NaLS + Sacc additives, was also dependent on current density, roughness of substrate, and the temperature of plating bath.

DEOXYGENATION OF SULFOXIDES TO THIOETHERS BY MOLYBDENUM PENTACHLORIDE (MOCL5) AND REDUCTIVE COUPLING OF SULFONYL CHLORIDES TO DISULFIDES

Molybdenum pentachloride (MoCl5) in the presence of Nal in dry acetonitrile or zinc powder in anhydrous THF converts sulfoxides to their thioethers in high yields. Sulfonyl chlorides can be readily reduced to their corresponding disulfides with MoCl5/Nal/MeCN at room temperature or with MoCl5/Zn/MeCN under reflux conditions in high yields.

Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides as mediators

Electrochemical oxidation of malonic esters in acetonitrile in the presence of iodides follows two different pathways depending on the nature of the cation. In the presence of Lil, alkyl 1,1,2,2,3,3-propanetetracarboxylates were obtained in 85–98% yields. In the presence of Nal, Kl, or Bu4NI, the formation of 1,1,2,2-ethanetetracarboxylates and their subsequent dehydrogenation to ethenetetracarboxylates was the main reaction pathway.

Use of micelles in photogalvanic cell for solar energy conversion and storage: Azur A-glucose system

Sodium lauryl sulphate (NaLS), tetradecyl trimethyl ammonium bromide (TTAB) and Brij-35 were used in a photogalvanic cell containing azur A as a photosensitizer and glucose as a reductant for solar energy conversion and storage. The photopotential and photocurrent generated by the cell in the presence of NaLS were 811.0 mV and 1470 μA, respectively. The effect of variation of the concentrations of the surfactants on the electrical output, the fill factor, the conversion efficiency and the performance of the cell in the dark was studied in detail.

Polymerization of methyl methacrylate in micellar phase: A kinetic study

AbstractPolymerization of methyl methacrylate (MMA) using Ce(IV) as initiator in aqueous nitric acid solution in the presence of sodium lauryl sulphate (NaLS) has been studied kinetically at a temperature range of 25–35°C. The rate of polymerization (Rp) increases with increasing concentration of NaLS, and it was also proportional to [MMA]2; but, in the presence of NaLS, the change of Rp with respect to [Ce(IV)] and [H+] were not linear and similarly the rate of Ce(IV) disappearance was not proportional to its original concentration. The overall activation energy of the polymerization process in presence of 0.01M NaLS was found to decrease by ∼ 7.0 kcal mol−1. The monomer–micelle association constant has been calculated to be 5.135 × 104 mol−1 L. The polymer obtained in surfactant medium is sparingly soluble in benzene and DMSO. From infrared spectra clear evidence of vinyl polymerization was obtained.

PHOTOELECTRIC EFFECTS FROM CHLOROPHYLL a IN BILAYER MEMBRANES

Abstract— Light flashes generated voltage transients across bilayer membranes in air‐saturated solutions which had chlorophyll a (Chi a) incorporated from one side. No other membrane or solution asymmetry was required. Symmetrical membranes containing Chi a also produced photovoltages after transmembrane NaCl gradients were established, and large membrane conductance changes when irradiated in the presence of Nal. The latter two effects were reduced when the oxygen tension was reduced, and are consistent with photoionization of Chi a producing porphyrin radicals and superoxide. Other oxidizing agents, CuS04, FeCl3, K3Fe(CN)6, (NH4)2Ce(N03)6 and S‐(2‐methyl‐l,4‐naphthquinonyl‐3)‐gutathione, increased the photoelectric effect's amplitudes when they came into contact with Chi a. The quantum efficiency with 5 mM K3Fe(CN)6 was estimated by the dual flash method to be 0.2 ± 0.1.

Effect of sodium lauryl sulfate on the polymerization of acrylonitrile

AbstractMicellar catalyzed polymerization of acrylonitrile using ceric(IV)–glycerol redox system in aqueous sulfuric acid solution in the presence of sodium lauryl sulfate (NaLS) has been studied. The polymerization experiments were conducted between 15°C and 25°C, under conditions where no oxidation of sodium lauryl sulfate by ceric ion would we expected. The rate of polymerization (Rp) increases with increasing concentration of NaLS. The rate of monomer (AN) disappearance was proportional to [AN]1.5 and [glycerol]0.5, but, however, Rp changes in a nonlinear manner with increase in Ce(IV) concentration in the presence of the surfactant. The rate of Ce(IV) disappearance was not proportional to its original concentration. The chain length of the polymer could not be determined viscometrically, as the polymer obtained in presence of NaLS was insoluble in organic solvents. The activation energy of this polymerization process was calculated by conducting the experiment at different temperatures. The infrared spectra of the polymers in the presence and absence of surfactant have also been examined.

Some Effects of Nalidixic Acid on Conjugation in Escherichia coli K-12

The role of deoxyribonucleic acid (DNA) synthesis in the Escherichia coli conjugation system has been studied using nalidixic acid (NAL) to specifically inhibit DNA synthesis in matings between reciprocal combinations of male (Hfr) and female (F(-)) mutants resistant and sensitive to NAL; the physiological action of NAL on the strains utilized was also studied. Matings between combinations of mutants resistant (Nal(r)) and sensitive (Nal(s)) to NAL allow various parental functions to be established: pair formation studies show that the female cells are responsible for the slight decrease in pair formation when NAL is present in Hfr(Nal(s)) x F(-) (Nal(s)) matings. Preformed mating pairs are stable in the presence of NAL. In matings between Hfr(Nal(s)) and F(-)(Nal(r)), the transfer gradient constant increases linearly with low NAL concentration (0.1 to 0.6 mug of NAL per ml). Higher concentrations of NAL (5 mug/ml) act on Nal(s) males to rapidly stop chromosome transfer; under these conditions, however, DNA degradation is unmeasurable as determined from single-strand nicking in the male cells. This result is consistent with a model for chromosome transfer which requires DNA synthesis in the male cell. Inhibition of DNA synthesis (by 85%) in the female has no effect on conjugal chromosome transfer. High concentrations of NAL (>20 mug/ml) produce slight inhibition in chromosome transfer for the Hfr(Nal(r)) x F(-)(Nal(r)) mating tested; this effect is probably caused by action of NAL on the male. The inhibition of chromosomal transfer by NAL appears to be irreversible in the normal sense. A pulse of NAL, applied during transfer, immediately stops the transfer which is in progress. On removal of the NAL block, the temporal appearance of recombinants is consistent with the idea that a new round of transfer has commenced from the sex factor location on the male chromosome.