Water-soluble content

A variety of techniques are used to determine the water-soluble content of a pigment. 

The plasma membrane of epithelial cells, in common with other cell types, is selectively permeable, allowing the penetration of some substances but not others. The construction of the membrane from amphipathic lipid molecules forms a highly impermeable barrier to most polar and charged molecules, thereby preventing the loss of most water-soluble contents of the cell. This selective permeability presents a physical barrier to drag absorption, limiting absorption to specific routes and mechanisms, as described below (see Section 1.3.3). 

Ji Q, Chen Y. 1996. Viciafaba root tip micronucleus test on the mutagenicity of water-soluble contents of cigarette smoke. Mutat Res 359 1-6. 

Moisture content, ash content, and water soluble content... 

The culture medium is an aqueous solution to which all the necessary nutrients have been added. A nutrient medium, designed by Koch, was based on the fact the microbes grow within host animals, including humans, hence meat infusions and extracts were chosen as basic nutrients the basic medium contained 0.5% peptone (an enzyme digest of meat), 0.3% meat extract (concentrated water-soluble contents of meat) and 0.8% sodium chloride (the same salt concentration as found in meat). Depending on the type and combination of nutrients, different categories of media can be made. The mixture of necessary nutrients can be used as a liquid medium or a... 

Water-soluble content it gives an estimation of purity in relation to water extractable substances. 

The hot-water solubles content or the hot dilute alkali (0.1 N NaOH) solubles content have been used as indexes of the amount of alkali-consuming polyphenols present. The values are only comparative, as the materials removed contain not only polyphenols but also organic acids and the simple carbohydrates. Nevertheless, useful information is obtained. In a study to determine the cooking conditions that would yield pulps of specified lignin content from pale-colored euca-lypts, a relationship was found between hot-water solubles and the amount of alkali consumed (31) ... 

Along with solubility in solvents, the pigment should also be checked for water-soluble content. Water-soluble components are restricted to a few parts per million. Pigments prepared by precipitation or... 

Chloride content. Samples for determining the chloride level in concrete are collected in the form of powder produced by drilling or by the extraction of cores, sections of which are subsequently crushed. The latter method can provide a more accurate chloride concentration depth profile. The chloride ion concentration, used as a measure of the risk of corrosion damage and degree of chloride penetration, is subsequently determined by potentiometric titration. Two distinctions are made in chloride ion concentration testing Acid-soluble chloride content (ASTM C 114) refers to the total chloride ion content, while the water-soluble content represents a lower value. 

Brandt et al. [21] polymerized a solution of 20% acrylic acid in water with a crosslinker such as MBA or TMPTA and an initiator such as hydrogen peroxide-ascorbic acid. Reaction temperature was maintained within the range of 10 - 65°C during an exothermic polymerization and thereafter at 40°C for 3 hours. The resulting gel was chopped in the presence of dilute sodium hydroxide solution (70 mole%), allowed to stand at 40 C for 16 hours and then dried at 80 C under reduced pressure. The resulting dry absorbent polymer exhibited an absorbency for synthetic urine of 38 g/g and water soluble content of 9%. 

The topic of membrane transport is discussed in detail in many texts (Alberts et al, 1989 Freshney, 2000). The following discussion is limited to membrane transport of small molecules, hence excluding macromolecules such as polypeptides, polysaccharides, and polynucleotides. The lipid bilayer is a highly impermeable barrier to most polar molecules and thus prevents the loss of the water-soluble contents of the cell interior. Consequently, cells have developed special means to transport these species across their membranes. Specialized transmembrane proteins accomplish this, each responsible for the transfer of a specific molecule or group of closely related molecules. The mechanism can be either energy independent, as in passive and facilitated diffusion, or energy dependent, as in active transport and group translocation. 

Esters can participate m hydrogen bonds with substances that contain hydroxyl groups (water alcohols carboxylic acids) This confers some measure of water solubil ity on low molecular weight esters methyl acetate for example dissolves m water to the extent of 33 g/100 mL Water solubility decreases as the carbon content of the ester increases Fats and oils the glycerol esters of long chain carboxylic acids are practically insoluble m water... 

Stoichiometric air—fuel volumetric ratio water solubility sulfur content, wt %... 

Antiblaze 1045 contains a larger amount of [42595-49-9]. Both materials are water-soluble thermally stable low volatihty hquids having about 20% phosphoms content and no halogen. 

Volatilization. The susceptibility of a herbicide to loss through volatilization has received much attention, due in part to the realization that herbicides in the vapor phase may be transported large distances from the point of application. Volatilization losses can be as high as 80—90% of the total applied herbicide within several days of application. The processes that control the amount of herbicide volatilized are the evaporation of the herbicide from the solution or soHd phase into the air, and dispersal and dilution of the resulting vapor into the atmosphere (250). These processes are influenced by many factors including herbicide application rate, wind velocity, temperature, soil moisture content, and the compound s sorption to soil organic and mineral surfaces. Properties of the herbicide that influence volatility include vapor pressure, water solubility, and chemical stmcture (251). 

Drying. In many cases, the high moisture content of young coals dictates significant drying (qv) before use. In some cases, partial removal of mineral matter, especially water-soluble species, is desirable. 

Synthetic manganese carbonate is made from a water-soluble Mn (IT) salt, usually the sulfate, by precipitation with an alkafl or ammonium carbonate. The desired degree of product purity determines the quaUty of manganese sulfate and the form of carbonate to be used. For electronic-grade material, where the content of K O and Na20 cannot exceed 0.1% each, the MnSO is specially prepared from manganese metal, and ammonium bicarbonate is used (26) (see Electronic materials). After precipitation, the MnCO is filtered, washed free of excess carbonate, and then, to avoid undesirable oxidation by O2, dried carefljlly at a maximum temperature of 120°C. 

Because the viscosity of neoprene latex at a given soHds content is less than that of natural mbber latex, thickeners are generally needed with the former. MethylceUulose and the water-soluble salts of poly(acryhc acid) are the two most commonly used thickeners. Natural and synthetic gums are also used. 

Films or membranes of silkworm silk have been produced by air-drying aqueous solutions prepared from the concentrated salts, followed by dialysis (11,28). The films, which are water soluble, generally contain silk in the silk I conformation with a significant content of random coil. Many different treatments have been used to modify these films to decrease their water solubiUty by converting silk I to silk II in a process found usehil for enzyme entrapment (28). Silk membranes have also been cast from fibroin solutions and characterized for permeation properties. Oxygen and water vapor transmission rates were dependent on the exposure conditions to methanol to faciUtate the conversion to silk II (29). Thin monolayer films have been formed from solubilized silkworm silk using Langmuir techniques to faciUtate stmctural characterization of the protein (30). ResolubiLized silkworm cocoon silk has been spun into fibers (31), as have recombinant silkworm silks (32). 

Natural Ethoxylated Fats, Oils, and Waxes. Castor oil (qv) is a triglyceride high in ticinoleic esters. Ethoxylation in the presence of an alkaline catalyst to a polyoxyethylene content of 60—70 wt % yields water-soluble surfactants (Table 20). Because alkaline catalysts also effect transestenfication, ethoxylated castor oil surfactants are complex mixtures with components resulting from transesterrfication and subsequent ethoxylation at the available hydroxyl groups. The ethoxylates are pale amber Hquids of specific gravity just above 1.0 at room temperature. They are hydrophilic emulsifiers, dispersants, lubricants, and solubilizers used as textile additives and finishing agents, as well as in paper (qv) and leather (qv) manufacture. 

These specifications include specific gravity, maximum water content, maximum values for toluene- or ben2ene-insoluble material, and maximum amounts distilling at 230°C, 270°C, 315°C, and 355°C. In the case of the AWPA specifications, there are minimum limits to the specific gravities of each of the distillate fractions in the case of the WEI specifications, limits for the contents of ben2o[a]pyrene and water-soluble phenols (tar acids). 

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