Aflatoxins in acid-treated grain in Sweden and occurrence of aflatoxin M1 in milk

A survey of aflatoxins in acid-treated grain and milk from farms using such grain was conducted in Sweden during 1986. Aflatoxins occurred most frequently (40%) in grain treated with a new formula of diluted (700 g litre^?1) aqueous formic acid, but also in 31% of the samples of grain treated with 850 g litre^?1 aqueous formic acid. The lowest incidence was found in grain treated with propionic acid, where aflatoxins were found in only one sample (3%). Aspergillus flavus/A parasiticus occurred in the same manner, but were more frequent than the aflatoxins. When cultivated on aflatoxin-producing agar, positive reactions were more common (56%) among strains originating from grain treated with formic acid than among strains originating from grain treated with propionic acid (4%). Aflatoxin M¹ in concentrations over 50 ng kg^?1 was mainly found in milk from farms using formic acid, and in most of these cases aflatoxins were also detected in the grain samples. In some cases, milk from a single farm was contaminated enough to generate consumption milk from the dairy with aflatoxin M¹ concentrations above or close to 50 ng kg^?1. The risk of aflatoxin formation after inadequate treatment of grain with formic acid is very high and is considerably lower with propionic acid. Formic acid has now been prohibited for use as a preservative of high moisture grain in Sweden.     

Optimization of geometry in truss design

In this paper a method is presented which attempts to minimize the weight of a 3-dimensional truss structure subject to displacement-, stress- and buckling constraints under multiple load conditions. Both the cross section areas of the bars and the geometry (but not the topology) of the structure are permitted to vary during the optimization.The method generates a sequence of subproblems which are solved by a dual method of convex programming. The convergence of the overall algorithm is in evidence on some test problems.     

Estimation of equation of state parameters for 1,1,1,2-tetrafluoroethane in a modified benedict-webb-rubin equation

Thermodynamic properties of refrigerants are of great importance in the design and simulation of heat pumps and refrigeration units. The parameter values in the modified Benedict-Webb-Rubin equation of state proposed by Lee and Kesler (1975) have been determined for HFC 134a with the Error-in-Variables Model. The types of data used for the parameter estimation have been: pressure-volume-temperature data for subcooled and superheated conditions, vapour pressures, saturated vapour and liquid volumes, isobaric arid isochoric heat capacities and second virial coefficients. Calculations carried out with the equation of state according to Lee and Kesler, with the parameters here proposed, agree well with experimental data for the fluid.     

Phase transfer catalysts as co-catalysts in the ethoxylation of nonyl phenol

Ethoxylation of nonyl phenol has been carried out at 130°C and at an absolute pressure of two bars. Alkali metal hydroxides were used as catalysts, either neat or in conjunction with added co-catalysts such as 18-crown-6 and tetramethyl ethylene diamine (TMEDA). The overall reaction rates were found to increase fivefold on the addition of the co-catalysts. The use of TMEDA as the sole catalyst gave equally high reaction rates. This fact can be explained by the high basicity of TMEDA and by the formation of a highly reactive ion pair similar to those found in phase transfer catalysis. The differences in the kinetics of the reactions were analysed by computer simulation, using a five parameter model. According to this model, the crown ether-catalyzed ethoxylation of nonyl phenol was found to proceedvia protonated ethylene oxide, while pure alkali catalysis proceeded mainlyvia uncomplexed ethylene oxide. Small differences in the oligomer distributions were noted.     

Survival after cardiac arrest outside hospital over a 12-year period in Gothenburg

BACKGROUND: A two-tiered ambulance system with a mobile coronary care unit and standard ambulance has operated in Gothenburg (population 434,000) since 1980. Mass education in cardiopulmonary resuscitation (CPR) commenced in 1985 and in 1988 semiautomatic defibrillators were introduced. Aim: To describe early and late survival after cardiac arrest outside hospital over a 12-year period. Target population: All patients with prehospital cardiac arrest in Gothenburg reached by mobile coronary care unit or standard ambulance between 1980 and 1992. RESULTS: The number of patients with cardiac arrest remained fairly steady over time. Among patients with witnessed ventricular fibrillation, the time to defibrillation decreased over time. The proportion of patients in whom bystander initiated CPR was increased only moderately over time. The proportion of patients given medication such as lignocaine and adrenaline successively increased. The number of patients with cardiac arrest who were discharged from hospital per year remained steady between 1981 and 1990 (20 per year), but increased during 1991 and 1992 to 41 and 31 respectively. CONCLUSIONS: Improvements in the emergency medical service in Gothenburg over a 12-year period have lead to: (1) a shortened delay time between cardiac arrest and first defibrillation and (2) an improved survival of patients with cardiac arrest outside hospital probably explained by this shortened delay time.     

Chalcogenide memory materials

The operating principles of an amorphous semiconductor non-volatile memory (ovonic memory switch) are reviewed. Methods for including the memory switch in bipolar integrated circuits with two levels of conductor are discussed. Electrical performance currently attainable from integrated memory devices of this type is outlined.     

On the validity of using small positive lower bounds on design variables in discrete topology optimization

It is proved that an optimal {ε, 1} ⁿ solution to a “ε-perturbed” discrete minimum weight problem with constraints on compliance, von Mises stresses and strain energy densities, is optimal, after rounding to {0, 1} ⁿ , to the corresponding “unperturbed” discrete problem, provided that the constraints in the perturbed problem are carefully defined and ε > 0 is sufficiently small.     

A study of vapour-liquid equilibria for the binary mixtures hcfc22/cfc114, hcfc22/hcfc142b and hcfc22/hfc152a

Experimental data for vapour liquid equilibrium for the three non-azeotropic mixtures HCFC22ICFC114 (CHClF_z/C_zCl_zF₄), HCFC22IHCFC142b (CHClF_z/C_z,/H₃ClF_z) and HCFC221HFC152a (CHClF_z/C_zH₄F_z) and vapour pressure for the pure components have been measured in pressure range up to 1.8 MPa. In a comparative study the deviations between experimental and calculated data for three correlation methods are presented. The three methods are the equations of state according to Lee-Kesler (1975) and Carnahan-Starling-de Santis (1976) and the activity coefficient model by Wilson (1964). Interaction parameters have been fitted from experimental data to the mixing rules proposed to the two equations of state and the activity coefficient parameters have been determined in the Wilson (1964) model. All three methods studied give good conformity with experimental data for the three mixtures examined.     

Is it possible to create a very large wordnet in 100 days? An evaluation

Wordnets are large-scale lexical databases of related words and concepts, useful for language-aware software applications. They have recently been built for many languages by using various approaches. The Finnish wordnet, FinnWordNet (FiWN), was created by translating the more than 200,000 word senses in the English Princeton WordNet (PWN) 3.0 in 100 days. To ensure quality, they were translated by professional translators. The direct translation approach was based on the assumption that most synsets in PWN represent language-independent real-world concepts. Thus also the semantic relations between synsets were assumed mostly language-independent, so the structure of PWN could be reused as well. This approach allowed the creation of an extensive Finnish wordnet directly aligned with PWN and also provided us with a translation relation and thus a bilingual wordnet usable as a dictionary. In this paper, we address several concerns raised with regard to our approach, many of them for the first time. We evaluate the craftsmanship of the translators by checking the spelling and translation quality, the viability of the approach by assessing the synonym quality both on the lexeme and concept level, as well as the usefulness of the resulting lexical resource both for humans and in a language-technological task. We discovered no new problems compared with those already known in PWN. As a whole, the paper contributes to the scientific discourse on what it takes to create a very large wordnet. As a side-effect of the evaluation, we extended FiWN to contain 208,645 word senses in 120,449 synsets, effectively making version 2.0 of FiWN currently the largest wordnet in the world by these statistics.