Dilute Hydrogen Chloride Research Articles

In English

Zeolite adsorbents and ion exchangers reducing the concentrations of contaminants in aqueous medium, containing bioactive metals and endowed with bactericidal properties are promising for application in environmental protection practice and medicine. Phillipsite has a high ion exchange capacity and can be used to produce such materials. Silver-, copper-, and zinc-containing micro-mesoporous zeolite materials have been prepared on the basis of natural phillipsite from the Shukhuti field, Western Georgia(Saqartvelo), using ion-exchange reactions between grinded and washed by dilute hydrogen chloride solution zeolite and a salt of a corresponding transition metal in the solid phase followed by washing with distilled water. Synthesized in such way adsorbent-ion-exchangers are characterized by chemical analysis and sorption data (nitrogen adsorption-desorption isotherms at 77 K and water vapour sorption at room temperature), powder X-ray diffraction patterns, Fourier transform infra-red spectra, and scanning electron microscope images. Obtained materials keep the crystal structure and general sorption and ion-exchange properties of phillipsite, they contain up to 230 mg/g of silver, 66 mg/g of copper, and 86 mg/g of zinc, which is several times higher than the content of bioactive metals in the cation-exchange forms of clinoptilolite and synthetic zeolites obtained by ion exchange in the liquid phase described in the literature. Prepared silver-, copper-, and zinc-containing phillipsites show bactericidal and bacteriostatic activity towards Escherichia coli regardless of whether the number of released ions of the bioactive metal reaches the minimum inhibitory concentration in solution. The procedure of dry ion-exchange synthesis leads to an increase in the dispersion of the material, but does not affect the developed mesoporous system of phillipsite and the total pore volume averaging 0.285 cm 3 /g. The compliance of proposed method for preparation of silver-, copper-, and zinc-containing forms of phillipsite with high environmental standards is confirmed by its low Sheldon’s factor E in comparison with the similar green chemistry metrics of conventional methods of the ion exchange in solutions.

Role of the Iron Axial Ligands of Heme Carrier HasA in Heme Uptake and Release

The hemophore protein HasA from Serratia marcescens cycles between two states as follows: the heme-bound holoprotein, which functions as a carrier of the metal cofactor toward the membrane receptor HasR, and the heme-free apoprotein fishing for new porphyrin to be taken up after the heme has been delivered to HasR. Holo- and apo-forms differ for the conformation of the two loops L1 and L2, which provide the axial ligands of the iron through His(32) and Tyr(75), respectively. In the apo-form, loop L1 protrudes toward the solvent far away from loop L2; in the holoprotein, closing of the loops on the heme occurs upon establishment of the two axial coordination bonds. We have established that the two variants obtained via single point mutations of either axial ligand (namely H32A and Y75A) are both in the closed conformation. The presence of the heme and one out of two axial ligands is sufficient to establish a link between L1 and L2, thanks to the presence of coordinating solvent molecules. The latter are stabilized in the iron coordination environment by H-bond interactions with surrounding protein residues. The presence of such a water molecule in both variants is revealed here through a set of different spectroscopic techniques. Previous studies had shown that heme release and uptake processes occur via intermediate states characterized by a Tyr(75)-iron-bound form with open conformation of loop L1. Here, we demonstrate that these states do not naturally occur in the free protein but can only be driven by the interaction with the partner proteins.

P‐149L: Late‐News Poster: Uniaxially Cracked ITO on PET Substrate and its Application in Flexible Displays

AbstractUniaxially cracked indium tin oxide (ITO) on a polyethylene terephthalate (PET) substrate and its application in replacing photolithography to make stripe ITO electrodes were developed. An ITO coated PET (ITO/PET) film uniformly and controllably rolled and uniaxially cracked. This procedure produced fine, parallel cracks in the ITO separated by 5∼10 microns. The crack separation and electrical isolation of the resulting long and thin ITO electrodes was enhanced by etching with dilute hydrogen chloride (HCl) or by uniaxially stretching. Heating and stretching proves the most effective, producing a crack width of about 0.05 microns and a differential conductivity (measured parallel and perpendicular to the cracks) in the resulting films greater than two orders of magnitude. A polymer dispersed liquid crystal (PDLC) shutter was prepared using the cracked ITO/PET film as one substrate. The addressed lines were defined by the contact electrode. The sharpness of the line edges increased as the drive frequency was increased. This PDLC prototype demonstrated how photolithographic etching of ITO or printing of conducting polymer could be replaced by controlled cracking of ITO to produce the line electrodes required for flexible, passive matrix displays and in related flexible electronic applications.

Is The Toxicity Of Bipyridylium Herbicides Two-Fold?

Is The Toxicity Of Bipyridylium Herbicides Two-Fold?

Electrolytic recovery of chlorine from hydrogen chloride gas with fused molten salt electrolyte LiCl/KCl

A method of electrolytic recovery of chlorine from hydrogen chloride gas based on the fused molten salt LiCl/KCl is under development. For the feasibility study, described here, a reticulated vitreous carbon (or porous carbon) cathode was immersed in a low-melting eutectic of LiCl/KCl. A graphite rod was used as the anode. Gaseous dilute hydrogen chloride, in a mixture with nitrogen, was reduced to elemental hydrogen and chloride at the cathode, and chlorine was produced at the anode. At stoichiometric current, current efficiency is greater than 90%. The removal efficiency is as high as 97%.

Correlation of Biological Value of Feed Phosphates with Their Solubility in Water, Dilute Hydrogen Chloride, Dilute Citric Acid, and Neutral Ammonium Citrate

Relative biological values (BV) of 36 feed phosphates were determined with female turkeys in bioassays of 21-day duration using three response criteria: weight gain, tibia ash percentage, and gain:feed ratio. Calcium phosphate, dibasic dihydrate (United States Pharmacopeia) was the reference standard. Nine mono-dicalcium phosphates (M-DCP, 21.0% phosphorus), 13 di-monocalcium phosphates (D-MCP, 18.5% phosphorus), and 14 defluorinated phosphates (DFP, 18.0% phosphorus) were evaluated. The average relative BV for M-DCP, D-MCP, and DFP samples were 97.6, 94.6, and 90.8%, respectively. Solubility of phosphates was determined by four recognized methods. The solvents were water, .4% HCl, 2.0% citric acid (CA), and neutral ammonium citrate (NAC). Water solubility of M-DCP samples was greater (67.5%) than that of D-MCP (38.8%) and DFP (8.9%) samples. Correlation of water solubility of phosphates to their relative BV was quite low, and water solubility was a poor indicator of BV. When .4% HCl was the solvent, correlation coefficients (r) were .55, .33, and .72 for M-DCP, D-MCP, and DFP, respectively. Based on these results and prediction equations, .4% HCl solubility would be inappropriate for estimating BV of M-DCP and D-MCP samples. Solubility of feed phosphates (mainly D-MCP and DFP) in 2.0% CA or NAC was positively correlated with BV; the r values were .87 to .95. Both of these solubility tests provided a good index of BV. However, it would seem inappropriate and risky to replace bioassays totally with these tests. Feed phosphate users could perform either the 2.0% CA or NAC solubility test easily as a screen for BV along with other quality control procedures (i.e., phosphorus, calcium, sodium, and fluoride determinations).

4-Methoxy-2,6-dimethylbenzenesulphonyl (Mds): a new protecting group of the guanidino function in peptide synthesis

The 4-methoxy-2,6-dimethylbenzenesulphonyl (Mds) group for the protectiono of the guanidino function, which is readily removed with trifluoroacetic acid–thioanisole but is resistant to hydrogenolysis or treatment with dilute hydrogen chloride, can be used in the solution synthesis of arginine-containing peptides; this protecting group was effectively used in the synthesis of substance P and two LH–RH analogues.

P-Tolylmethylsulphonyl: a new amino-protecting group in peptide synthesis

The p-tolylmethylsulphonyl group for the protection of the Iµ-amino group of lysine, which is readily removed with anhydrous hydrogen fluoride but is strongly resistant to trifluoroacetic acid or dilute hydrogen chloride, can be applied to both solid-phase and solution synthesis of peptides.

Proton longitudinal relaxation time measurements in dilute hydrogen chloride gas

Experimental measurements of the proton longitudinal relaxation time in dilute hydrogen chloride gas are reported. The measurements were made at room temperature, at 61 MHz and for gas densities between 0.005 and 0.5 amagat. The scalar spin–rotation interaction provides the dominant relaxation mechanism. The data are well accounted for using existing relaxation theory and the single relaxation time approximation. The experiment provides a fundamental test of nuclear spin relaxation theory for a gas of heteronuclear diatomic molecules.

Phosphonitrilic chloride: 33. Cyclomatrixphosphazene polymers formed from hexachlorocyclotriphosphazene and metal acetates

Cross-linked polymers of the metaphosphomic type structure were prepared by the reaction of hexachlorocyclotriphosphazene with various divalent metal acetates in aqueous solution at 30°C. The poorly crystalline insoluble products swell in water and most organic solvents. The product containing barium was the most stable toward heat. The products were easily decomposed by dilute hydrogen chloride at 80°C.

Studies on Silicified Tissues of Leaf in Rice Plant by Spodogram-Hydrogen Chloride Treatment Method.

When studied on silicified tissue of plant by histochemical method, Grob's phenol method was used as the most popular technique. But this method did not caused by chemical reaction of silicate, silicified tissues of leaf in rice plant was not cleared enough. In this studies we separated pure silicified tissues from leaf spodogramm by adding dilute hydrogen chloride. Results are summarized as follow: 1. Figure 1 to figure 6 shows the silicate accumulating process as the growth of leaf blade. In these figures we found the dumbbell form cell was most rapidly silicified and other epidermis cells were also beginning to silicified gradually. But when the leaf blade emerges from the leaf sheath of under leaf, these cells have been silicified almost completely. 2. Silicified motor cells of matured leaf are shown in figure 7, 8, 13 and 14. Situation of motor cells in leaf blade tissue are shown in figure 9, 10 and 11. According to these figures, motor cell's square shape in figure 7 is the same as bottom line of motor cell in figure 12 (C). 3. Leaf sheath also was silicified completely as figure 15 to figure 17. Leaf sheath node was partially silicified as form as net showing in figure 18.

Physiological and Ecological Studies of Rice Plant in Well-drained and Ill-drained Field. : (8) Distribution of silicified tissues of rice culm and silicate content in each internode as affected by diffierent cultural conditions.

Silicified tissues of rice culm were ascertained by following technique; the spodgrammes of internode, culm-node and leaf sheath-node were made, and then they were dissolved by heated dilute hydrogen chloride. As silicified tissue is insoluble, the silicified tissue in epidermis of internode, epidermis at the bottom of internode, inner parts of culm-node, node-plate and node-plate abutting on the culm could be observed under microscope as shown in Fig. 1-8. The culm differs from leaf blade in that the culm contains silicate in various tissues, while leaf blade contains was found silicate only in epidermis. Silicate content in internode was found closely related with growth stages and cultural conditions as summarized below: 1) Seasonal changes of silicate content in each internode indicate that percentages of silicate content at harvesting time are in higher level than that at heading time. 2) Relation with cultural conditions; a) As compared with ill-drained field, rice culm in well-drained field contained more silicate, especially in upper internodes (N1∼N3). b) In plot with heavy application of nitrogen, amount of silicate content in upper internodes was less. c) Silicate content in lower internode was high in plot with silicate calcium application.

Mass Transfer in Liquid-Solid Agitation Systems

The authors conducted experiments on the solution of solid particles in agitated liquids in a series of geometrically similar agitators. A great variety of solid particles, including several kinds of spherical crystals, whose particle size, shape and density varied over a wide range, were used as solid samples. Pure water, dilute hydrogen chloride and aqueous solutions of gelatine, polyvinyl alcohol, sucrose and glycerine of various concentrations were used as liquids.Between the agitator speeds of Nf and Na, all the data were correlated by the following dimensionless equations.For solid particles with an unknown surface shape factor, (13)and for solid particles with a known surface shape factor, (14)where(24)and(10)These equations represent the general correlation of the variables involved in determining the magnitude of the rate of mass transfer in agitated liquid-solid systems, and are used-to estimate the mass transfer rate for any liquid-solid combination in a series of geometrically similar vessels and impellers.