Prior research suggests that alliances created between retailers provide numerous benefits for their members which result in higher retail performance. The paper investigates whether the size of a firm is a moderating variable and/or an alternative explanation in studying the effect of alliance membership on the retailer’s performance. An empirical study, based on a small-scale survey, was carried out among 99 small-and medium-sized retailers in Hungary. Not only the strength but also the form of the relationship between alliance membership, performance and firm size have been investigated. Findings of the research support that firm size changes the form of causal relationship between alliance and performance of a retailer. Size contributes substantially to the variation of retail performance and increases the impact of alliance membership on sales and profit growth of retailers.
Crystallisation is generally regarded as a nucleation — growth mechanism of a solid phase and often studied using thermo chemical
methods. The present work postulates an analogy to melting processes, looking at melting as nucleation — growth of a liquid
phase. The melting process of acetylsalicylic acid single crystals was investigated by DSC measurements under isothermal conditions.
The fraction of material molten after a certain time period, α(t), was calculated by integrating the DSC curves. The resulting kinetic curves were fitted using the Avrami-Erofeev equation:
–ln(1–α)=ktn, where parameter n was analysed. According to established methods, functions I('2')=[t('2')]/[t('2')+t('3')]100% and I('3')=[t('3')]/[t('3')+t('2')]100% were introduced, where t('2') and t('3') is the absolute time of consumption two- and three-dimension nuclei growth, respectively. Applying correlation analysis,
relationships between two- or three-dimensional growth and the independent variables describing the single crystals (for strictly
definite trajectories into the space of sizes) were found. Particular correlations were:a) Two-dimensional growth is a function
of the total surface area of the crystal, S, and of the surface area of the (ac)-face, Sac; b) Three-dimensional growth is a function of S/M (where M is the mass of the single crystal). It is also a function of Sac/M and of S. The obtained experimental data are explained by the ‘layer’ structure of crystals of acetylsalicylic acid.
An isothermal titration calorimetry (ITC) method
to measure the heat effects evolving from the binding between cation exchanger
Amberlite IRP 69 and the cationic drug substances propranolol hydrochloride
(PROP), metoprolol tartarate (METO), acebutolol hydrochloride (ACEB) and chlorpheniramine
maleate (CPR) has been developed. The method gives repeatable results with
an error about 5% for the beta-blockers PROP, METO and ACEB, and about 10%
for the antihistamine CPR.
The calculation of the thermodynamic parameters enthalpy
and Gibbs free energy change (ΔGbind)
show significant differences between the different drug substances.
Single crystals of the N,N-dimethylformamide (DMF) solvate (1:1) of flurbiprofen (FBP) were grown for the first time and characterised
by X-ray diffraction, IR spectrophotometry, DSC and solution calorimetric methods. The structure may be characterised as a
layer-structure, where DMF double-sheets are arranged between FBP double-sheets. The FBP and DMF molecules are linked to each
other by a hydrogen bond, which is formed between the hydroxyl group of FBP and the carbonyl group of DMF. The conformation
of FBP molecules in the DMF solvate differs from analogous enantiomers in the unsolvated form. The differences are discussed
from the point of view of the influence of the nature of the solvent on selective crystallisation of the enantiomers. A peculiarity
of the solvate is its low melting point, 37.30.2C, with respect to the unsolvated phase, 113.50.2C. Based on solution
enthalpies of the solvated and unsolvated phases dissolved in DMF, the difference in crystal lattice energies, 9.8 kJ mol-1, was calculated and the difference in entropies, 33 J mol-1 K-1 estimated. A possible mechanism explaining the low melting point of the solvate is discussed.
association has been mentioned in the Hungarian coenological literature, but has not been confirmed by relevés until present. The authors give relevés from the Bakony Mts, the Mecsek Mts and from two sampling sites of the Northern Mountain Range. The stands of the
association scattered in the middle-montane areas of Hungary are compared with another association of shaded forest rocky vegetation more widespread in submontane regions.
The thermodynamic energy relationship between two crystal modifications of cimetidine was investigated and compared with differences in their processing properties with respect to transformation from one modification to the other.The crystal energies of the two modifications A and D were found to be almost identical and therefore the polymorphs are regarded as virtually isoenergetic crystals. This statement is based on DSC measurements of the melting points and of the enthalpies of fusion for the two crystal forms, which enable the calculation of the Gibbs free energy functions. Furthermore, the statement is supported by measurements of the enthalpies of solution in two different solvents. Both DSC and solution experiments reveal a slightly higher stability of the D modification with respect to the A form. In addition, tribomechanical treatment also indicates modification D to be the more stable one, as well as the higher density of the D form. No transformation during DSC at low heating rate was found which could be used in a stability consideration.As the explicit crystal structures of the two modifications are resolved, it was possible to calculate crystal energies theoretically as well. The theoretical results showed a remarkable difference in the crystal energies at zero degree Kelvin. Furthermore, they were just contradicting experimental findings by stating A being more stable than D. Possible reasons for this discrepancy and the feasibility of today's calculation methods with respect to prediction of stability properties are discussed.
A novel radiochemical separation for 48V radiotracer in no-carrier-added (NCA) form, via proton irradiation on Ti targets of natural isotopic composition has been developed. Metallic Ti targets irradiated with 21 MeV proton beam energy was submitted to a selective radiochemical separation consisting of an alkaline fusion-precipitation step, followed by column Chelex-100 chromatographic purification. Very high specific activity 48V, at levels of hundreds MBq .µg-1 was prepared. Chemical analysis of radiotracer was carried out by ET-AAS and INAA. The decontamination factor from Ti target was 5 . 105, with an overall radiochemical yield for 48V larger than 90&. The NCA 48V has used for labeling a range of chemical forms of V(III, IV, V) and applied in the study of metabolic behavior of different chemical forms in in-vivo and in-vitro experiments on rats and cell cultures.
The first version of the map of the Hungarian vegetation-based landscape regions were prepared at the scale of 1: 200,000 (1 km or higher resolution). The primary goal of the map was to provide an exact background for the presentation and evaluation of the data of the MÉTA database. Secondly, we intended to give an up-to-date and detailed vegetation-based division of Hungary with a comprehensive nomenclature of the regions. Regions were primarily defined on the basis of their present zonal vegetation, or their dominant extrazonal or edaphic vegetation. Where this was not possible, abiotic factors that influence the potential vegetation, the flora were taken into consideration, thus, political and economical factors were ignored. All region borders were defined by local expert botanists, mainly based on their field knowledge. The map differs in many features from the currently used, country-wide, flora-or geography-based divisions in many features. We consider our map to be temporary (i.e. a work map), and we plan to refine and improve it after 5 years of testing.