Water-sensitive papers

Water-sensitive papers are readily available in most countries and provide a convenient system for visually assessing spray drift performance. These papers are coated with bromoethyl blue, which turns from yellow to blue when contacted with water. " However, since any water can cause this change in color, care needs to be taken to prevent accidental exposure to sources of water other than the pesticide. Such cards do not work well under humid conditions, and are not appropriate for sampling droplets with diameter below 15 qm. Quantitative estimates of droplet size distributions must take account of the exponential increase in droplet volume as the droplet diameter increases. As droplets strike the paper, the liquid spreads over the surface and leaves a stain with a size that is dependent on the volume of the droplet. The apparent droplet size will be greater for large droplets than for small droplets, and the size determination must be corrected to avoid bias. 

Drop size measurements were made on water sensitive papers exposed inside cooling towers at various levels. Results are given for samples taken under eliminators, over eliminators and high in towers. Design and operational factors which affect the values are discussed. Droplet removal efficiencies are given for conventional louvre eliminators and for louvre eliminators modified with plastic meshes. 

Spray deposition can be monitored using water-sensitive paper or glossy white cards in conjunction with an added coloured dye. Alternatively, a fluorescent... 

Site and Application Procedures. The orchard site and air application equipment were the same as described by Currier (1982). In 1980, ground applications were made with an Ag-Tech low volume air blast sprayer, calibrated to deliver 187 1/ha, and in 1981, with a Kinkelder low volume air blast sprayer calibrated to deliver 94.6 1/ha. From previous studies of MacCollom et al ( ) and Currier ( ) it was known that the air application gave a median droplet size diameter of 100 to 150 pm. Estimation of particle size, as measured on water sensitive paper, for ground equipment was 75 to 110 pm. Application rates for captan 80W in both years was 3.12(AI) Kg/ha, and for carbaryl 80S, 2.24(AI) kg/ha. 

Prussian Blue. Reaction of [Fe(CN)3] with an excess of aqueous h on(Ill) produces the finely divided, intensely blue precipitate Pmssian Blue [1403843-8] (tetrairon(Ill) tris(hexakiscyanoferrate)), Fe4[Fe(CN)3]. Pmssian Blue is identical to Turnbull s Blue, the name which originally was given to the material produced by reaction of [Fe(CN)3] with excess aqueous h on(Il). The soHd contains or has absorbed on its surface a large and variable number of water molecules, potassium ions (if present in the reaction), and h on(Ill) oxide. The h on(Il) centers are low spin and diamagnetic h on(Ill) centers are high spin. Variations of composition and properties result from variations in reaction conditions. Rapid precipitation in the presence of potassium ion affords a colloidal suspension of Pmssian Blue [25869-98-1] which has the approximate composition KFe[Fe(CN)3]. Pmssian Blue compounds are used as pigments in inks and paints and its formation on sensitized paper is utilized in the production of blueprints. 

Barrels and Heaters These are also similar to those in extruder machines. In recent years, vented barrels have become available to facilitate the moulding of water sensitive plastics without the need for pre-drying. Water sensitivity in plastics can take several forms. If the plastic absorbs water then dimensional changes will occur, just as with wood or paper. The plastic will also be plasticised by the water so that there will be property changes such as a reduction in modulus and an increase in toughness. All these effects produced by water absorption are reversible. 

Place Arcol Polyol F-3022 (100 g, 0.1 eq., 56 OH, mixed PO/EO triol from Bayer) into a suitable container. To this add distilled water (3.3 g, 0.4125 eq.), Niax Silicone L-620 (0.5 g, a silicone surfactant from OSi Specialties), and Niax C-183 (0.12 g, an amine catalyst from OSi Specialties). Thoroughly blend this mixture without incorporating air bubbles. Then add Dabco T-9 (0.25 g, stannous octoate from Air Products) and mix again. The T-9 must be added last because it is quite water sensitive, so its exposure to the water-containing polyol blend should be kept to a minimum. To this polyol blend, quickly add Mondur TD-80 (42.6 g, 0.4868 eq., a mixture of 80% 2,4-TDI and 20% 2,6-TDI isomers from Bayer) and immediately stir at 3000 rpm for 5 s. Quickly pour the reaction mixture into a suitable container such as a 1-qt paper or plastic cup and allow the foam to free-rise. The stir blade may be wiped or brushed clean. 

Sediment deposition. Horizontal surfaces collect particles primarily by sedimentation deposition, sometimes referred to as fallout . These can provide valuable information relating to exposure for horizontal surfaces in the field such as water and ground. Most studies measuring spray performance within the application area, and/or outside this area by drift, include horizontal collectors. The most common types of such collector include flat papers, cards and plates. Water- and oil-sensitive papers have been widely used for looking at the uniformity of spray coverage, coefficient of variation, droplet densities and approximate droplet size within a spray block. 

Holcomb, D.L. Callaway, R.E. Curry, L.L. "Foamed Hydrocarbon Stimulation Water Sensitive Formations", SPE paper 9033, 1980 SPE Rocky Mountain Regional Meeting, Casper, May 14-16. 

Kucera, C.H., Smith, C.F. and Braunlich, F.H. "New Oil Gelling Systems Prevent Damage in Water Sensitive Sands," SPE paper 3503, 1971 SPE Annual Meeting, New Orleans, October 3 6. 

The work of Mosko [116] is important in that he is one of the few workers who have given serious consideration to the determination of nitrite in water. His paper is concerned with the determination of chloride, sulphate, nitrate, nitrite, orthophosphate, fluoride and bromide in industrial effluents, waste water and cooling water. Two types of analytical columns were evaluated (standard anion and fast run series). Chromatographic conditions, sample pretreatment and the results of interference, sensitivity, linearity, precision, comparative and recovery studies are described. The standard column provided separation capabilities which permitted the determination of all seven anions. The fast run column could not be used for samples containing nitrite or bromide owing to resolution problems. 

Vitenberg et al. [623] have described a gas chromatographic method for the determination of traces (down to l-10pg kg ) of sulphur compounds, such as hydrogen sulphide, mercaptans, sulphides and disulphides, in industrial waste waters (kraft paper mill effluents) by a combination of headspace analysis and microcoulometiy. This method increases the analytical sensitivity 102-103 times without any preliminary concentration of the sample. 

Significant improvements have also been introduced with the use of heterogeneous catalysts that are less water-sensitive than homogeneous Lewis acids and more convenient because of easier reaction mixture work-up. An important class of MPVO solid catalysts consists of zeolite beta and its metal-containing derivatives, especially Sn-, Zr- and Ti-beta. Several examples are known and the reduction or oxidation can be performed either in the gas phase [11, 12] or in solution [13, 14]. A very recent paper also reports the use of a bifunctional Zr-beta-sup-ported Rh catalyst able to promote both arene and carbonyl reduction [15],... 

Abstract Chalk is the constituent material of numerous oil reservoirs in North Sea. The mechanical behaviour of a saturated chalk has been largely studied. However, different aspects of its behaviour are not yet well understood material characteristics depend on the saturating fluids and chalk response is time-dependent. This paper proposes the PASACHALK numerical model an elasto-plastic constitutive law is presented, which reproduces the different plastic mechanisms of the chalk (pore collapse and shear failure) and the influence of pore fluids. The water sensitivity of this soft rock is explained by the existence of suction effects in chalk. Finally, a simulation of a hypothetical reservoir is proposed to show the response of the elasto-plastic model during depletion phase and water injection phase. 

The flotation test is a rough method to identify plastics since results are dependent on the physical form of the material. Foams contain cells filled with air, so their densities will be lower than a solid block of identical dimensions of the same type of plastic. Water-sensitive or absorbent fillers such as paper... 

In contrast to their widespread use in furniture and paper products, animal glues have not proved useful as struetural adhesives for wood. When used as the principal protein constituent, their water sensitivity is excessive compared with other available proteins. When eombined with soybean, blood, or casein, animal gelatin glues are completely hydrolyzed and destroyed by the strong alkalies required to disperse these proteins. In addition, they soften when severely heated, which, by law, prohibits their use in structural wood products [5]. 

Chem. Descrip. Polyol carbonyl adduct Uses Insolubilizer for paper coalings incl. food-contact paper Fealwes Reacts with functional groups of coating binders reduces water sensitivity inc. number of impressions and print quality in the offset printing process Regulatory FDA approved Properties Dens. 10.7 Ib/gal pH 4.5 55% total solids SER-AD FA 153 [Sasol Servo BV ... 

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