Influence Of Different Proportions Research Articles

Optimization of glibenclamide tablet composition through the combined use of differential scanning calorimetry and d-optimal mixture experimental design

A systematic analysis of the influence of different proportions of excipients on the stability of a solid dosage form was carried out. In particular, a d-optimal mixture experimental design was applied for the evaluation of glibenclamide compatibility in tablet formulations, consisting of four classic excipients (natrosol as binding agent, stearic acid as lubricant, sorbitol as diluent and cross-linked polyvinylpyrrolidone as disintegrant). The goal was to find the mixture component proportions which correspond to the optimal drug melting parameters, i.e. its maximum stability, using differential scanning calorimetry (DSC) to quickly obtain information about possible interactions among the formulation components. The absolute value of the difference between the melting peak temperature of pure drug endotherm and that in each analysed mixture and the absolute value of the difference between the enthalpy of the pure glibenclamide melting peak and that of its melting peak in the different analyzed mixtures, were chosen as indexes of the drug–excipient interaction degree.

Investigations on breeding plans for organic dairy cattle

Abstract. facilities in Germany, different alternative breeding plans for organic cattle breeding were developed using the computer program ZPLAN. First the impact of the population size on the parameters of success was analysed. A conventional cattle breeding program was compared with an organic breeding program. The results indicate that the selection response increased with increasing population size due to improved selection of bull sires. The EU Regulations on organic farming say that the proportion of artificial insemination has to be reduced as much as possible. According to this, the influence of different proportions of artificial insemination on the monetary genetic gain was investigated. The reduction of artificial insemination below 50% led to high losses in the discounted profit. The influence of higher economic weights for functional traits on the natural selection response was investigated. An increase of the economic weights by 50% led to tolerable decreases in the natural selection response of production traits with regard to a more ecological orientated breeding goal. The effect of the variation of the test capacity and the number of test bulls on the monetary genetic gain was analysed. The optimum for the monetary genetic gain was located at a test capacity of 50%, 30 test bulls and 99 daughters per test bull.

EVOLUTION OF STUDENTS' STUDYING ATTITUDES ON THE CELLULAR AUTOMATA MODEL

In this paper, we propose a model of studying attitude evolution on campus. With the Cellular Automata (CA) model, we divide the students into five groups with different studying attitudes, and discuss the influence of different proportions of students with different studies on the whole studying attitude. With the definition of the concrete correlations of the individuals, we simulate the evolution of studying attitude on campus.

Profiles of volatile compounds and sensory analysis of three blends of coffee: influence of different proportions of Arabica and Robusta and influence of roasting coffee with sugar

AbstractOne hundred and forty‐six volatile compounds were identified and quantified using a static headspace sampler in three blends of coffee: Arabica/Robusta 80:20 (A80:R20) natural roasted coffee, Arabica/Robusta 20:80 (A20:R80) natural roasted coffee and Arabica/Robusta 20:80 with 50% of Robusta coffee roasted with sugar (A20:R80 50% Torrefacto). The different proportion of Arabica and Robusta coffee in the blend A80:R20 versus A20:R80 influenced the amounts of 20 chemical families of volatile compounds. Aldehydes, ketones, alcohols, pyrroles, pyrazines, furans, thiazoles, thiophenes, esters, oxazoles, lactones, sulphur compounds, pyridines, alkanes, alkenes, phenolic compounds, benzenic compounds, acids, pyranones and terpenes were present in higher quantities in the sample containing 80% of Arabica coffee, whereas sulphur compounds were more abundant in the coffee with 80% of Robusta. Sensory differences were also found between the two blends of coffee in the burnt, caramel, nutty, earthy and roasty notes. Torrefacto coffee, widely consumed in Spain, is obtained by roasting coffee with sugar. Higher quantities of ketones, alcohols, pyrazines, furans, pyridines, alkanes, phenolic compounds, pyranones and terpenes were found in the blend A20:R80 50% Torrefacto coffee versus A20:R80 natural roasted coffee. These differences in the volatile fraction were perceived by our panellists in the intensities of the nutty, roasty, earthy, burnt and caramel notes.© 2002 Society of Chemical Industry

Hybrid Female Matings Are Directly Related to the Availability of Rana lessonae and Rana esculenta Males in Experimental Populations

In the hybridogenetic frog complex Rana lessonae and Rana esculenta, mate choice based on genetic benefit could be an important form of sexual selection. The hybrid R. esculenta, must coexist with the parental species R lessonae, which functions as a genetic host. The two types occur in varying ratios in natural populations depending on environmental conditions of the aquatic habitat. In highly disturbed habitats such as gravel pits, R. esculenta is most common, whereas R. lessonae is more frequent under less disturbed environmental conditions. To examine the influence of different proportions of males of the two types on mating success, we subjected hybrid females to different ratios of R. lessonae and R. esculenta males in artificial pools. Our results show that females mated according to the availability of the two types of males in the pools. However, combining data over all ratio treatments suggested a slightly higher mating frequency for R. lessonae males than for R. esculenta males, although the R. esculenta males behaved more aggressively, called more often, and tended to orient more frequently toward females than did R lessonae males. This, plus results from previous mate choice studies, suggests that R. esculenta females have a preference for mating with R. lessonae males because of genetic benefits; but which mate a female finally mates with is also influenced by other processes, such as the availability of the two male types at the time of mate choice as well as the strength of male-male competition.

Solvent extraction of uranium(VI) by LIX-54 and its mixtures

Studies on solvent extraction of uranium(VI) by a commercially available chelating extractant LIX-54 (a β-diketone derivative) (HA) and its mixtures with tri-n-butyl phosphate (TBP) in benzene diluent show quantitative extraction by a mixture of 5% LIX-54 and 5% TBP at pH 4.3. Influence of different proportions of LIX-54 or TBP in the mixtures on the extraction of the same metal ion has been studied. Pronounced synergism has been observed. The composition of the extracted species seems to be [UO2(OH)(A)(HA)(TBP)] as determined from slope analysis. Slopes of the linear plots were computed employing regression analysis and variance in results has been shown.

The strength of industrial cokes. 5. Influence of coke breeze in a coal charge on tensile strength of coke

The purpose of this study was to determine the influence of different proportions and different particle sizes of coke breeze in a coke-oven charge on the tensile strength of the coke. The diametrical-compression test was used to determine the tensile strength of the coke produced in a 10-t test oven and the results obtained were considered in relation to the composition of the oven charge, the coke micum indices and to parameters describing the coke texture. It was established that breeze additions caused measurable but nonsystematic changes in the coke tensile strength and that decreasing the breeze particle size generally increased the coke tensile strength. These changes could not however be directly related to changes observed in the density, porosity, pore-wall thickness or mean pore size of the cokes. The previously established relations between micum indices and the tensile strength of foundry cokes were also found to be inapplicable. The conclusion was drawn that the behaviour described is associated with some, at present unestablished, factor of the blend composition, one possibility being the relative proportions and compatibility of the ‘binder’ and inert material acting through their influence on those aspects of the coke microstructure which control the coke breakage.

Condensation of aldehydes with malonic acid

Condensations of protocatechuicaldehyde, vanillin and veratraldehyde with malonic acid in the presence of various proportions of bases, and in the absence of any base, show that the hydroxy-group generally diminishes the yield, which rises when the group is methylated. Influences of different proportions of the base, and of different temperatures and periods of time at which the reactions are allowed to proceed are recorded. The trace of the base is generally as efficient as ever. The nitro-group on the other hand, when present on the nucleus, is not found to exert any restraining influence on the yields obtained, and allows very high yields of the nitro-cinnamic acids.

Studies of the Influence of Various Dietary Conditions on Physiological Resistance: I. The Influence of Different Proportions of Protein in the Food on Resistance to the Toxicity of Ricin and on Recuperation from Hemorrhage

Studies of the Influence of Various Dietary Conditions on Physiological Resistance: I. The Influence of Different Proportions of Protein in the Food on Resistance to the Toxicity of Ricin and on Recuperation from Hemorrhage

Studies of the influence of various dietary conditions on physiological resistance. I. The influence of different proportions of protein in the food on resistance to the toxicity of ricin and on recuperation from hemorrhage.

It was planned to compare, in these experiments, the behavior of two sets of dogs under variously induced pathological conditions. The experiments were conducted on two pairs of dogs, each pair being kept under identical conditions, so far as they could be controlled, except with respect to the food. One animal of each pair was given liberal amounts of protein in the daily diet, the other received barely sufficient protein to provide for the necessary nitrogenous metabolism, the remaining ingredients of the food for each animal being uniformly equal to the daily amounts ordinarily given per kilo, in this laboratory, to perfectly healthy dogs. No attempt was made to maintain equal caloric values in the diets. In each experiment the animal was fed on a diet of hashed lean meat, cracker meal and lard, the meat being gradually increased or diminished to a high or low plane, according to the plan in each case and before the particular pathological condition was induced.