A method for estimating the dust yield of powders

A method is described by which powders may be compared with respect to their potential to liberate airborne dust during certain manufacturing processes. Thus it is possible to select quickly from a range of otherwise suitable powders the powder with the lowest dust yield, which reduces the precautions required to prevent exposure of factory personnel to the dust.A weighed quantity of the powder is poured through a standard height in a cabinet. Airborne dust, irrespective of particle size (“total” dust), is collected on a weighed filter in an open filter holder and, in a separate test, after passage through a horizontal elutriator which separates respirable dust capable of penetrating to and being deposited in the human lung. The weights of respirable and “total” dust are expressed in relation to the weight of powder tested.     

A rapid method for estimating glycerol in kettle soap

Journal of the American Oil Chemists' Society -     

A dye-dilution method for estimating solids content of plastic fats

Summary Solids content of a plastic fat can be estimated by adding a weighed quantity of oil-soluble dye to a known weight of fat, separating a portion of the dyeoil phase in the ultracentrifuge, and determining the concentration of the dye in the separated oil by absorbance measurements. Since the dye is distributed throughout the oil phase, this yields the amount of oil in the spread; solids represent the difference between the amount of spread taken and the amount of oil determined. Of 37 dyes tested, 1,4-bis-methyl aminoanthraquinone and 1,4-bis-isopropyl aminoanthraquinone gave satisfactory results for global edible spreads in which solids contents were known from the formulation. The method also was applied to the estimation of solids in butter, margarine, lard, and shortening. Except for lard, results were in good agreement with solids content determined by dilatometric measurements. The measure of true solids which is obtained by this technique, without prior melting of the fat sample, would be valuable in the study of consistency changes arising from diverse processing conditions. Separation of oil phase from a plastic fat by pressure filtration or by capillary absorption in filter paper was less satisfactory than centrifugation in the dye-dilution method. Presented at the meeting of the American Oil Chemists' Society, Chicago, Ill., Nov. 2–4, 1953.     

A simple method for estimating carbonyl content in peroxide-containing oils

A simple method is described for the estimation of carbonyl content in peroxide-containing oils. In this method, peroxides, which interfere with carbonyl determination, are reduced with triphenyl phosphine prior to carbonyl determination. Carbonyl content is measured by a colorimetric 2,4-dinitrophenyl hydrazone procedure. Neither triphenyl phosphine nor triphenyl phosphine oxide, oxidation products of triphenyl phosphine by reaction with peroxides, interfere with the measurement of carbonyl content. The method is applicable to several kinds of oxidized oils in any oxidation stage.     

Improved dye method for estimating protein

Several improvements and extensions of the Udy dye method for estimating protein content in natural products are discussed. The many outstanding physical and chemical properties of the monosulfonic azo dye, acid orange 12, are presented. This dye is used in a stablizing pH 2 buffer system to react with the protein’s basic groups that originate from the basic amino acids (BAA) histidine, arginine and lysine. A complete analysis requires less than 5 min. The ionic reaction rate is limited to the exposure rate of each binding site. Regression equations relating nitrogen content and bound dye are presented for several oilseeds, grains, legumes and animal products. Random mixtures of products, having wide dif-ferences in dye-binding capacity, are not amenable to this method of protein estimation. Because nonpro-tein nitrogen is not measured, and the critically essential amino acid, lysine, is measured only when it is nutritionally available, it is suggested that the amount of dye bound by the protein’s BAA offers a better nutritional index than conventional nitrogen procedures. One of four papers being published from the Symposium “Sampling and Process Control in the Oilseed Industry,” presented at the AOCS Meeting, New Orleans, April 1970.     

一种计算搅拌槽混合时间的新方法

基于对混合时间定义的思考,提出了一种新的定义方法,在湍流流场数值计算的基础上通过求解示踪剂的浓度输运方程,研究了单层涡轮桨搅拌槽内的混合过程。结果表明：搅拌转速和搅拌桨安装位置都影响混合时间的大小,而进料位置对混合时间的影响不大。对于不同的搅拌转速而言,随搅拌转速的增大,相同体积分数对应的混合时间逐渐减小。当搅拌桨安装在槽中间位置时所对应的混合时间最小。利用适宜的尺寸和安装位置的导流筒可有效降低混合时间。     

A conductimetric method for the study of mixing phenomena in liquids

A new conductimetric microprobe and conductimeter have been designed to study mixing phenomena in fluids of non-uniform composition in turbulent flow. For the case of a parallelepipedic cell with two parallel jets at different salt tracer concentrations, the spatial distribution and the mean and variance of the fluctuation of the tracer are obtained experimentally and used to characterise the state of local mixing.A theoretical expression for the mean concentration is obtained by solving the convective diffusion equation. Comparison of experimental and theoretical results is satisfactory and proves to be a sufficiently good test of the reliability of the apparatus used.     

A method for estimating sensitivity of commercial explosives to practical types of initiation

A method for estimating sensitivity of commercial explosives to practical types of initiation—aNo. 8 blasting cap, a detonating fuse, and a booster—is proposed. The results of experiments withAS-8A granulite, granulotrinitrotoluene, and79/21 grammonite of bulk density are given. Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 142432. Translated from Fizika Goreniya i Vzryva, Vol. 33, No. 1, pp. 107–110, January–February, 1997.     

A method for estimating both the solubility parameters and molar volumes of liquids

The solubility parameters and molar volumes of substances can be used, in conjunction with suitable theory, to provide estimates of the thermodynamic properties of solutions; the solubility characteristics of polymer-solvent systems and the estimation of the equilibrium uptake of liquids by polymers are examples of the type of practical problems that are amenable to treatment. For low molecular weight liquids, the solubility parameter, δ, is conveniently calculated using the expression δ = (ΔE_v/V)½, where ΔE_v is the energy of vaporization at a given temperature and V is the corresponding molar volume which is calculated from the known values of molecular weight and density. For high molecular weight polymers, the volatility is much too low for ΔE_v to be obtained directly and hence recourse must be made to indirect methods for estimating δ for these materials. One such widely used method is based on Small's additive group “molar-attraction constants” which when summed allow the estimation of δ from a knowledge of the structural formula of the material; however, the density must still be determined experimentally. The proposed method of estimating δ, also based on group additive constants is believed to be superior to Small's method for two reasons: (1) the contribution of a much larger number of functional groups have been evaluated, and (2) the method requires only a knowledge of the structural formula of the compound.     

A method for computing the degree of mixing in steady continuous flow systems

The degree of mixing was first proposed by Danckwerts and further discussed by Zwietering more than 50 years ago to measure mixing performance of a continuous flow system. Although the measure has been widely discussed in mixing literature, there has never been a method to compute its value for a general continuous flow. In this paper, a method is developed to compute this measure for a general steady continuous flow system for the first time. The method is based on the recently developed mean age theory. The governing equations for the mean age and higher moments of age are also derived for different types of tracer introduction other than pulse input in the current mean age theory.     

A method of estimating entropies of coals and coal liquids

A method for estimating entropies of both solid and liquid fuels is proposed. An example showing calculation of availability of coal is presented. Entropy and availability of coal calculated are compared with those obtained by other methods. Deviations among different methods examined are discussed.     

A new method of estimating standard enthalpies of formation of zeolites

A new method to calculate the standard enthalpies () of formation of zeolites is founded based on the assumption that the standard enthalpy of formation of zeolite is equal to the sum of the standard enthalpies of all oxide components and the reaction standard enthalpy change between the exchangeable ion oxide and alumina. The results show that the deviation of of zeolite calculated by this method is less than 0.7% compared with the experimental value of . The standard enthalpy of formation of hypothetical [SiO₂] unit in zeolite is suggested to estimate the thermodynamic stability of zeolite. It is found that the presence of crystal water in zeolite is in favor of increasing the thermodynamic stability of zeolite.     

A new method for estimating the cellular structure of plastic foams based on dielectric anisotropy

The characterization of the cellular structure of plastic foams has long been of importance to investigate their physical properties. We have been developing an instrument that measures the orientation of seat materials based on their dielectric anisotropy. It is demonstrated by electromagnetic theory that composite materials with an island-sea structure show a macroscopic anisotropy of dielectric constant because of the shape of islands, even if both the islands and sea are dielectrically isotropic themselves. The orientation based on the dielectric anisotropy caused by the shape of cells was investigated for the polystyrene by using our microwave cavity resonator method. From this data, a better manufacturing condition to minimize the thermal shrinkage was derived. The manufacturing condition was taken as extrusion rate, foaming temperature and die gap. The shape of cells of polystyrene foams was estimated using the derived equations, which express the maximum and minimum dielectric constant of whole composite materials as a function of the eccentricity of their ellipsoidal islands and the volume fraction and the dielectric constant of each materials in the islands-sea structure.     

An improved method for estimating the feed-size breakage distribution functions

The discrete-size equation of batch grinding in cumulative fraction retained has an approximate, but adequately accurate, solution in the form of a second-order polynomial in time. For a single-size feed, the leading coefficient G of the polynomial is the product of the feed-size breakage-rate constant and the breakage distribution function. This coefficient as well as the second coefficient H are readily computed from the grinding data by solution of two linear algebraic equations, or by least squares, or by simple graphical techniques. In the last case, a new method of graphical display of grinding data as straightline plots is presented the intercepts of which are breakage distribution functions. Using both computer-generated as well as experimental grinding data, it is shown that the proposed G-H method of estimating breakage distribution functions is highly accurate, is not restricted to short grinding time data and is not subjected to any restrictive interrelationship between breakage-rate constants and breakage distribution functions. As such, this method is an improvement over the existing schemes, i.e. the method based on zero-order production of fines and the BII method, which are in fact shown to be time-restricted and grinding parameters-restricted specialized cases of the more general G-H method.