ABSORPTION, TRANSLOCATION AND EXUDATION OF DICHLOBENIL AND VERNOLATE IN FIELD HORSETAIL

1982 ◽  
Vol 62 (4) ◽  
pp. 983-988 ◽  
Author(s):  
D. COUPLAND ◽  
D. V. PEABODY
Keyword(s):  
Aqueous Solution ◽  
Root Exudates ◽  
Laboratory Experiments ◽  
Equisetum Arvense ◽  
Root Exposure

The absorption, translocation and exudation of 14C-labelled dichlobenil (2,6-dichlorobenzonitrile) and vernolate (S-propyl-dipropylthiocarbamate) in field horsetail (Equisetum arvense L.) were examined in glasshouse and laboratory experiments. When applied as a vapor, more dichlobenil was absorbed than vernolate, irrespective of whether the roots or shoots were exposed to the herbicide vapors. Neither herbicide was translocated to the shoots after root exposure to the 14C-vapor, but a small amount was translocated to the roots after shoot exposure. When applied in aqueous solution to the roots and rhizomes, more 14C was recovered from the rhizomes of plants treated with vernolate. Both herbicides were concentrated at the rhizome nodes. Small amounts of 14C (less than 0.5% of the applied activity) were found in the guttation fluid and in root exudates.

Experiments and Molecular Simulations to Study the Role of Coadsorption of Oil in Corrosion Inhibitor Films in Improving Corrosion Mitigation

CORROSION ◽  
10.5006/3606 ◽  
2020 ◽  
Vol 76 (11) ◽  
Author(s):  
Xueying Ko ◽  
Juan Dominguez Olivo ◽  
Bruce Brown ◽  
Srdjan Nešić ◽  
Sumit Sharma
Keyword(s):  
Aqueous Solution ◽  
Corrosion Inhibitor ◽  
Metal Surfaces ◽  
Laboratory Experiments ◽  
Field Experience ◽  
Molecular Simulations ◽  
Self Assembled Monolayer ◽  
Polar Head ◽  
Self Assembled

While both field experience and laboratory experiments have shown that the efficiency of adsorbed corrosion inhibitor films improves upon exposure of the aqueous solution to a hydrocarbon phase, a credible explanation of these results is lacking. Using a combination of experiments and molecular simulations, this study examines how exposure to oil molecules affects the nature of adsorbed corrosion inhibitor films on metal surfaces. It is found that oil molecules get coadsorbed in the corrosion inhibitor films, making them more hydrophobic, structurally more ordered, and well packed. Corrosion inhibitor molecules with a bulky polar head adsorb in nonplanar, cylinder-like morphologies. Coadsorption of oil molecules changes the morphology of these films to a planar self-assembled monolayer.

Chlorine Dioxide Gas from an Aqueous Solution: Reduction of Salmonella in Wounds on Tomato Fruit and Movement to Sinks in a Treatment Chamber

2009 ◽  
Vol 72 (5) ◽  
pp. 952-958 ◽  
Author(s):  
MICHAEL MAHOVIC ◽  
JERRY A. BARTZ ◽  
KEITH R. SCHNEIDER ◽  
JOEL D. TENNEY
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Potassium Iodide ◽  
Chlorine Dioxide ◽  
Initial Dose ◽  
Laboratory Experiments ◽  
Tomato Fruit ◽  
Chlorine Dioxide Gas ◽  
Viable Cells ◽  
Source To Sink

Chlorine dioxide (ClO2) off-gassed from an aqueous solution and reacted incrementally with potassium iodide solutions (sinks). After 30 min, 45% of the initial dose was detected as chlorite ion in the sink, whereas 35% of the initial dose was still in the source. Aqueous solutions of ClO2 can be used as a source of ClO2 gas in various laboratory experiments involving treatment of fruits or vegetables. Movement from source to sink is continuous, which precludes the development of large headspace concentrations and the need for a tight chamber seal. When the source solution has dissipated, the chamber can be opened safely as there is little free ClO2 remaining in the headspace. In tests with whole, wound-inoculated tomato fruit, at both green and pink stages of ripeness, the control of Salmonella enterica serotype Typhimurium in wounds varied with the weight of gas used. The number of viable cells of Typhimurium recovered was reduced by >5 log units when ≥0.5 mg of ClO2 was applied to three pieces of fruit during a 2-h treatment.

Interaction of Surfactants and Reaction Media on Photolysis of Chlorimuron and Metsulfuron

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 620-624 ◽  
Author(s):  
S. Kent Harrison ◽  
Sandra M. Thomas
Keyword(s):  
Aqueous Solution ◽  
Liquid Chromatography ◽  
Water Glass ◽  
Laboratory Experiments ◽  
Nonionic Surfactants ◽  
Aqueous Media ◽  
Glass Slides ◽  
Leaf Residue ◽  
Corn Residue ◽  
Reaction Media

Laboratory experiments were conducted to determine the effects of nonionic surfactants and reaction media (water, glass, and corn leaf residue) on photolysis and subsequent phytotoxicity of chlorimuron and metsulfuron residues. Oxysorbic and octoxynol enhanced rates of chlorimuron and metsulfuron photolysis in aqueous solution and on glass slides compared to controls with no surfactant. Enhanced photolysis of chlorimuron by surfactants was greatest on glass, where 93 and 89% loss occurred after 48 h exposure to ultraviolet light in the presence of oxysorbic and octoxynol, respectively, compared to 38% loss with no surfactant. Similarly, surfactant-enhanced metsulfuron photolysis was greatest on glass with 37 and 67% loss after 48 h exposure in the presence of oxysorbic and octoxynol, respectively, compared to 9% loss with no surfactant. Photolysis of herbicides deposited on corn leaf residue was significantly slower than that on glass or in aqueous media at all exposure times and metsulfuron photolysis on corn residue was enhanced by surfactants only after 144 h exposure. Bioassays confirmed that phytotoxicity of photolyzed herbicide residues was negatively correlated (r=-0.94 for chlorimuron and r=-0.92 for metsulfuron) with loss of parent herbicide as measured by liquid chromatography.

scholarly journals Features of Urea influence on physicochemical properties of working solutions of insecticides

2021 ◽  
pp. 8-11
Author(s):  
О. Vlasova ◽  
M. Sekun ◽  
M. Zatserklyana
Keyword(s):  
Aqueous Solution ◽  
Surface Tension ◽  
Physicochemical Properties ◽  
Aqueous Solutions ◽  
Technological Process ◽  
Laboratory Experiments ◽  
Plant Protection ◽  
Analytical Analysis ◽  
Field Crops ◽  
Evaporation Of Droplets

Goal. To study the effect of Urea on the properties of working solutions of emulsions and suspensions of chemical and microbiological drugs in plant protection against pests. Methods. Information-analytical analysis of the effectiveness of joint use of insecticides with Urea. Laboratory experiments on the effect of Urea on: evaporation of droplets from the treated surface; surface tension; reaction of the medium of suspensions and emulsions of working solutions of chemical and microbiological preparations. To do this, in aqueous solutions of insecticides and biological products in concentrations recommended for use in field crops, was added 0.2% aqueous solution of Urea. After a certain period of time, the characteristics of the solutions were determined. An analytical generalization of the change in the properties of working solutions under the influence of urea is carried out. Results. The information on the possibilities of joint use of insecticides and microbiological preparations with Urea in a single technological process is generalized. Their combination leads to a significant reduction in the evaporation of solution droplets from the treated surface, but does not affect the surface tension and reaction of the solutions. Conclusions. Urea is an active anti-evaporator of working solutions of insecticides of various nature. Adding it to the solutions of evaporation of drops from the treated surface reduces more than 1.5 times. It does not significantly affect the surface tension and reaction of the solution. This characteristic of the solutions is maintained for 24 hours after preparation.

Covering of cometary nucleus by refractory crust and its evolution into asteroid-like body

1999 ◽  
Vol 173 ◽  
pp. 365-370
Author(s):  
Kh.I. Ibadinov
Keyword(s):  
Laboratory Experiments ◽  
Cometary Nucleus ◽  
Sublimation Rate ◽  
Cometary Nuclei ◽  
Short Period Comet ◽  
Short Period ◽  
Brightness Decrease ◽  
Crust Thickness ◽  
Ice Sublimation ◽  
Period Comet

AbstractFrom the established dependence of the brightness decrease of a short-period comet dependence on the perihelion distance of its orbit it follows that part of the surface of these cometary nuclei gradually covers by a refractory crust. The results of cometary nucleus simulation show that at constant insolation energy the crust thickness is proportional to the square root of the insolation time and the ice sublimation rate is inversely proportional to the crust thickness. From laboratory experiments resulted the thermal regime, the gas productivity of the nucleus, covering of the nucleus by the crust, and the tempo of evolution of a short-period comet into the asteroid-like body studied.

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

1990 ◽  
Vol 48 (4) ◽  
pp. 1094-1095
Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley
Keyword(s):  
Aqueous Solution ◽  
Affinity Chromatography ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Coverage ◽  
Vacuum Impregnation ◽  
Thin Sections ◽  
Selective Staining ◽  
Low Viscosity ◽  
Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

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