Infinite dilution activity coefficients of solvents in fatty oil derivatives Ferreira, O.; Foco, Gloria Margarita Inverse gas-liquid chromatography has been applied to measure infinite dilution activity coefficients (γ ∞) of different solutes in low and high molecular weight triacylglycerides (TAGs) and in mixtures of carboxylic acids with TAGs. The γ ∞ data obtained were used to determine binary interaction and size related parameters for the GCA-EOS group contribution with association equation of sate.

Optimization of the operating conditions of azeotropic distillation columns with pervaporation membranes Hoch, Patricia Monica; Daviou, Maria Carolina; Eliceche, Ana Maria The main objective of this work is the optimization of the operating conditions of azeotropic distillation columns in hybrid distillation/pervaporation systems. In the configuration analyzed, a liquid side stream extracted from the azeotropic distillation column with the distributing non-key component is treated in a pervaporation membrane while the retentate is recycled to the column. The pervaporation membrane separates the pure distributing non-key component from the mixture, thus helping to improve the purity in the top and/or bottom products of the distillation column. The case study shows the hybrid process of a distillation column combined with pervaporation membranes, compared to the classical two-column process for Methyl tert-Butyl Ether production. In both cases, the operating conditions of the distillation columns such as reflux ratio, product and side draw flowrates are selected optimally. The numerical results show a significant reduction in operating cost obtained by using a pervaporation membrane instead of the second column in the original process.

Restricted weak type inequalities for convolution maximal operators in weighted Lp spaces Bernardis, Ana Lucia; Martín Reyes, Francisco Javier Let φ: ℝ → [0, ∞) be an integrable function such that φ(-∞,0) = 0 and φ is decreasing in (0, ∞). Let τh f (x) = f (x - h), with h ∈ ℝ/{0} and φ R(x) = (1/R)φ(x/R), with R > 0. In this paper we study the pair of weights (u, v) such that the operators Mτhφ f (x) = supR>0 |f| * [tau;hφ]R (x) are of restricted weak type (p, p) with respect to (u, v), 1 ≤ p < ∞. As particular cases, these operators include some maximal operators related to Cesàro convergence. We characterize those functions φ for which Mτhφ is of (restricted) weak type (p, p) with respect to the Lebesgue measure. Unlike the case of the Cesàro maximal operators, it follows from the characterization that the interval of those p such that M τhφ is of weak type (p, p) can be left-closed, [p 0, ∞], or left-open, (p0, ∞], without having restricted weak type (p0, p0).

New evolutionary models for massive ZZ Ceti stars, I : first results for their pulsational properties Althaus, Leandro Gabriel; Serenelli, A. M.; Corsico, Alejandro Hugo; Montgomery, M. H. Chaotic orbits suffer significant changes as a result of small perturbations. One can thus wonder whether the dynamical friction suffered by a satellite on a regular orbit, and interacting with the stars of a galaxy, will be different if the bulk of the stars of the galaxy are in regular or chaotic orbits. In order to check that idea, we investigated the orbital decay (caused by dynamical friction) of a rigid satellite moving within a larger stellar system (a galaxy) whose potential is nonintegrable. We performed numerical experiments using two kinds of triaxial galaxy models: (1) the triaxial generalization of Dehnen's spherical mass model (Dehnen; Merritt & Fridman); (2) a modified Satoh model (Satoh; Carpintero, Muzzio, & Wachlin). The percentages of chaotic orbits present in these models were increased by perturbing them. In the first case, a central compact object (black hole) was introduced; in the second case, the perturbation was produced by allowing the galaxy to move on a circular orbit in a logarithmic potential. The equations of motion were integrated with a non-self-consistent code. Our results show that the presence of chaotic orbits does not affect significantly the orbital decay of the satellite.

Up-regulated expression of MICA on activated T lymphocytes involves Lck and Fyn kinases, and signaling through MEK1/ERK, p38 MAP kinase and calcineurin Molinero, Luciana Lorena; Fuertes, Mercedes Beatriz; Fainboim, Leonardo; Rabinovich, Gabriel Adrián; Zwirner, Norberto Walter Major histocompatibility complex class I-related chain (MICA) is a cell stress-regulated molecule recognized by cytotoxic cells expressing the NKG2D molecule. MICA can be induced on T cells after CD3 or CD28 engagement. Here, we investigated the intracellular pathways leading to activation-induced expression of MICA. The Src kinase inhibitor PP1 inhibited up-regulated expression of MICA on anti-CD3-stimulated T cells. Downstream signaling routes involved mitogen-activated protein kinase (MAPK) kinase (MEK)1/extracellular signal-regulated kinase (ERK), p38 MAPK, and calcineurin, as MICA expression was prevented by U0126, SB202190, cyclosporin A, and FK506. Also, Lck and Fyn as well as MEK1/ERK and p38 MAPK were found to regulate MICA expression in anti-CD28/phorbol 12-myristate 13-acetate-stimulated T cells. Expression of MICA on activated T cells involved interleukin-2-dependent signaling routes triggered by Janus tyrosine kinases/signal transducer and activators of transcription and p70S6 kinase, as it could be inhibited by AG490 and rapamycin. This is the first demonstration of the intracellular pathways involved in activation-induced expression of MICA, which may reveal potential targets for immune intervention to modulate MICA expression in pathological disorders.

Role of prolactin in the regulation of cytosolic NADP isocitrate dehydrogenase in the liver of the male rat Zirulnik, Fanny; Anzulovich Miranda, Ana Cecilia; Larregle, Ethel Viviana; Jahn, Graciela Alma; Gimenez, Maria Sofia The activity of cytosolic NADP-linked isocitrate dehydrogenase (ICDH) in rat liver was determined. The administration of 2-bromo-α-ergocryptine (CB-154) to male rats produced a significant increase of the enzyme activity and a decrease of serum prolactin (PRL) levels in relation to control animals. Male rats 21 days after castration had lower levels of serum prolactin and higher activity of the enzyme than controls. Injection of PRL to castrated male rats lowered the enzymatic activity to control values. In intact rats injected with prolactin, the activity of the enzyme also decreased. Female rats were separated into the following groups: (a) virgins; (b) rats on day 15 of lactation; (c) ovariectomized rats. The enzymatic activity was similar in the different groups, but significantly higher than in male rats. However, serum PRL was significantly increased in 15 days lactating rats and decreased in ovariectomized ones in relation to virgins. We conclude that PRL regulates hepatic ICDH activity in male, but not in female rats. Incubation of isolated hepatocytes from intact or castrated male rats maintained the difference in ICDH activity observed in vivo, while there were no differences in ICDH activity in non-parenchymal cells. Addition of PRL, CB-154, androgens or antiandrogens to isolated hepatocytes from intact and castrated rat, had no effect on the ICDH activity, suggesting that the effect of PRL is exerted at the transcriptional level.

Extraction of molybdenum by a supported liquid membrane method Basualto, Carlos; Marchese, Jose; Valenzuela, Fernando R.; Acosta, Adolfo Francisco This is a report on the extraction of molybdenum(VI) ions using a supported liquid membrane, prepared by dissolving in kerosene, the extractant Alamine 336 (a long-chain tertiary amine) employed as mobile carrier. A flat hydrophobic microporous membrane was utilised as solid support. Appropriate conditions for Mo(VI) extraction through the liquid membrane were obtained from the results of liquid-liquid extraction and stripping partition experiments. The influence of feed solution acidity, the carrier extractant concentration in the organic liquid film and the content of strip agent on the metal flux through membrane were investigated. It was established that maximal extraction of metal is achieved at a pH 2.0 if sulphuric acid is used in the feed solution and at a pH value over 11.0 if Na2CO3 is used as strip agent. Moreover, the molybdenum extraction through membrane is enhanced when a 0.02 mol 1-1 content of the amine carrier in the organic phase is used. The present paper deals with an equilibrium investigation of the extraction of Mo(VI) by Alamine 336 and its permeation conditions through the liquid membrane, and examines a possible mechanism of extraction.

Weather regimes in the South American sector and neighbouring oceans during winter Solman, Silvina Alicia; Menendez, Claudio Guillermo We classified 34 years of winter daily 500 hPa geopotential height patterns over the eastern South Pacific-South America-South Atlantic region using the K-means clustering method. We found a significant classification into five weather regimes (WRs) defined as the most frequent large-scale circulation anomalies: WR1 (trough centred downstream of the Drake Passage), WR2 (trough over the SW Pacific and ridge downstream), WR3 (ridge over the SE Pacific and NW–SE trough downstream), WR4 (trough over the SE Pacific and NW–SE ridge downstream) and WR5 (weak ridge to the west of southern South America). We also analysed their persistence and temporal evolution, including transitions between them and development around onsets and breaks of each regime. The preferred transitions, WR1→WR3→WR2→WR4→WR1 and also WR1→WR3→WR2→WR1, suggest the progression of a Rossby wave-like pattern in which each of the regimes resemble the Pacific-South America modes. Significant influence of the WRs on local climate over Argentina was found. The preferred transitions WR1→WR3 and WR3→WR2 induce sustained cold conditions over Patagonia and over northern Argentina, respectively. The most significant change in precipitation frequency is found for WR3, with wetter conditions over all the analysed regions. Finally, the interannual to interdecadal significant variations in the occurrence of these regimes were discussed. WR1 and WR3 are more frequent and WR2 is less frequent during El Niño, and WR2 and WR5 are more frequent and WR1 is less frequent during La Niña. A significant decrease in WR2 and increase of WR4 and WR5 during the 1970s and early 1980s were found.

Post-mortem analysis of formic acid disposition in acute methanol intoxication Ferrari, Luis Alberto; Arado, Miriam G.; Nardo, Cesar A.; Giannuzzi, Leda Fifteen cases of fatal massive methanol intoxication have been investigated. Victims received either no treatment or ethanol therapeutic treatment. Methanol poisoning cases were classified in three groups according to survival time: more than 3 days (group 1), up to 3 days (group 2) and few hours (group 3). Body distribution of methanol and formic acid, as the main metabolite, was analyzed in blood and in different organs (brain, kidney, lung and liver). Relationships between formic acid concentration in the different tissues, survival time and type of treatment applied to victims were studied. Formic acid in blood and tissues was analyzed by head space gas chromatography (head space-GC) with FID detector, previous transformation in methyl formate, essentially as described by Abolin. Formic acid concentration was between 0.03 and 1.10g/l in the samples under study. A good correlation between blood and brain, but poor between blood and the remaining tissues was found. Obtained data suggested that the use of blood and brain could help to improve the analysis of formic acid intoxication. The best correlation among organs was found between lung and kidney for all groups (r2=0.91, 0.84 and 0.87, corresponding to groups 1, 2 and 3, respectively). Lethality index was defined as LI = (concentration of formic acid in blood in (g/l)/0.5) × 100, taking into account that 0.5g/l is the concentration reported by Mahieu in severe methanol poisoning. LI parameter was used to estimate formic acid incidence on the lethality of methanol poisoning cases. LI showed a good correlation with total formic acid concentration of the different tissues analyzed (r2=0.80). Furthermore, LI allowed us to discriminate between individuals that received therapeutic treatment and survived different periods. LI>100 indicated a severe intoxication and short survival time if the victim was assisted with ethanol therapy and hemodialysis was not applied. With regard to victims who received no therapeutic treatment and died in few hours, LI was in the range 40-100. LI was below 40 for individuals that survived more than 3 days and hemodyalisis was not performed. Results showed the importance of performing formic acid analysis to diagnose severe methanol intoxication in post-mortem cases.

Predictive Functional Control based on Fuzzy Model: Comparison with linear predictive functional control and PID control Lepetic, Marko; Skrjanc, Igor; Chiacchiarini, Hector Gerardo; Matko, Drago The implementation of the fuzzy predictive functional control (FPFC) on the magnetic suspension system is presented in the paper. The magnetic suspension system was in our case the pilot plant for magnetic bearing and is an open-loop unstable process, therefore a lead compensator was used to stabilize it. The high quality control requirements were a-periodical step response and zero steady-state error. Adding the integrator to a feedback causes overshoot. The solution to the problem was cascade control with fuzzy predictive functional controller in the outer loop. To cope with the unknown model parameters and the nonlinear nature of the magnetic system, a fuzzy identification based on FNARX model was used. After successful validation the obtained fuzzy model was used for controller design. The FPFC is compared with a cascade linear predictive functional control (PFC) and PID control. The results we obtained with the FPFC are very promising and hardly comparable with conventional control techniques.

Isotropic and anisotropic components of the neutron emissions at the FN-II and PACO dense plasma focus devices Castillo, F.; Herrera, J. J. E.; Rangel, J.; Milanese, Maria Magdalena; Moroso, Roberto Luis; Pouzo, Jorge Osvaldo; Golzarri, J. I.; Espinosa, G. The average angular distribution of neutron emissions has been measured in the Fuego Nuevo II (FN-II) dense plasma focus device (5 kJ) by means of CR-39 plastic nuclear track detectors. When pure deuterium is used as the filling gas, the data can be adjusted to a Gaussian function, related to anisotropic emission, superposed on a constant pedestal, related to isotropic emission. When deuterium–argon admixtures are used, the anisotropic contribution is best represented by a parabola. The same analysis is applied to previously reported results, for fewer shots, in pure deuterium from the PACO device, which is similar in size to the FN-II. In both devices the anisotropic component is smaller than the isotropic one, but with different features. In PACO the anisotropic component is concentrated on a large narrow beam around the axis, but its contribution to the total neutron yield is significantly smaller than in the FN-II, where the anisotropic component spreads over a wider range. The neutron flux per shot is monitored in both devices with calibrated silver activation detectors, at 20˚ and at 90˚ from the axis. The average values of the neutron flux at these two angles are used, along with the angular distributions obtained form the track detectors, in order to estimate the absolute neutron yield of both the isotropic and the anisotropic contributions. From examining different groups of shots, it is found that the shape of the angular distribution is important in the estimation of anisotropy, and that the value usually reported, as the ratio of neutron counts head-on and side-on, as measured by activation counters, may be misleading.

Theory of braided Hopf crossed products Guccione, Jorge Alberto; Guccione, Juan Jose We define a type of crossed product over braided Hopf algebras, which generalizes the ones introduced by Blattner, Cohen and Montgomery and Doi and Takeuchi, and we study some of its properties. For instance, we prove a Maschke´s Theorem for these new crossed products and under suitable hypothesis we construct a natural Morita context which extends the one obtained by Cohen, Fischman and Montgomery.

On the composition of the integral and derivative operators of functional order Hartzstein, Silvia Inés; Viviani, Beatriz Eleonora In this work we show that the composition of the integral and derivative operators of order phi, T_phi = D_phi◦I_phi, is a singular integral operator.This result in addition with the results obtained in [HV2] of boundedness of I_phi and D_phi or the T1-theorems proved in [HV1] yield the fact that T_phi is a Calderón-Zygmund operator bounded on the generalized Besov and Triebel-Lizorkin spaces of functional order.

Bulk hydrosilylation reaction of poly(dimethylsiloxane) chains catalyzed by a platinum salt: Effect of the initial concentration of reactive groups on the final extent of reaction Roth, Leandro E.; Vallés, Enrique M.; Villar, Marcelo Armando Model silicone networks obtained by curing linear poly(dimethylsiloxane) (PDMS) chains with end-vinyl groups, (B2), with a polyfunctional silane-terminated crosslinker of functionality f, (Af), through a hydrosilylation reaction have been widely used. In these networks, the principal characteristics of their ultimate molecular structure are strongly affected by the final extent of reaction reached during the crosslinking reaction. This work analyzes the effect of the initial concentration of the reactive end groups on the maximum attainable extent of reaction under normal bulk crosslinking conditions. This was accomplished by examining the reaction between linear B2 PDMS chains with difunctional and trifunctional silanes. The experimental results were fitted by an exponential equation to have an empirical equation able to predict the maximum extent of reaction to be obtained as a function of the initial concentration of reactive groups. Molecular parameters relevant to this study, such as the degree of polymerization, the weight-average molecular weight for the A2 + B2 system, or the weight fraction of solubles for the A3 + B2 system, were calculated with a mean field theory (recursive approach).

Intestinal passive absorption of hydrosoluble compounds by sparrows: effect of molecular size and luminal nutrients Chediack, Juan Gabriel; Caviedes Vidal, Enrique Juan Raul; Fasulo, Sara Veronica; Yamin, L. J.; Karasov, William We tested predictions that: (1) absorption of water-soluble probes decreases with increasing molecular size, consistent with movement through effective pores in epithelia, and (2) absorption of probes is enhanced when measured in the presence of luminal nutrients, as predicted for paracellular solvent drag. Probes (L-arabinose, L-rhamnose, perseitol, lactulose; MW 150.1–342.3 Da) were gavaged in nonanesthetized House sparrows (Passer domesticus), or injected into the pectoralis, and serially measured in plasma. Bioavailability was calculated as F=AUC by gavage/AUC by injection, where AUC is the area under the curve of plasma probe concentration vs. time. Consistent with predictions, F declined with probe size by 75% from the smallest to the largest probe, and absorption of probes increased by 40% in the presence of luminal glucose or food compared to a mannitol control. Absorption of water-soluble probes by sparrows is much higher than in humans, which is much higher than in rats. These differences seem mainly attributable to differences in paracellular solvent flux and less to differences in effective paracellular pore size.

The two isoforms of the cAMP-dependent protein kinase catalytic subunit are involved in the control of dimorphism in the human fungal pathogen Candida albicans Cloutier, Monikca; Castilla Lozano, Maria del Rocio; Bolduc, Nathalie; Zelada, Alicia Mercedes; Martineau, Philippe; Bouillon, Marlène; Magee, Beatrice B.; Di Bernardo, Maria Susana; Giasson, Luc; Cantore, Maria Leonor We have cloned the Candida albicans TPK2 gene encoding a cAMP-dependent protein kinase (PKA) catalytic subunit and generated a tpk2 homozygous null mutant to assess its ability to germinate in liquid media. N-acetylglucosamine (GlcNAc)-induced germ-tube formation was attenuated in the tpk2 strain and enhanced by compounds that are known to increase the PKA activity in situ. Germination was completely blocked in the presence of the myristoylated derivative of the heat-stable PKA inhibitor (MyrPKI). These results indicate that TPK1 acts positively in regulating the morphogenetic transition in C. albicans in the absence of the TPK2 gene. We were able to identify an mRNA from this second form of PKA in both wild-type and tpk2 null mutant cells. We found that PKA activity measured in the mutant lacking the TPK2 gene was about 10% of that displayed by the wild-type. The finding that the germinative response of tpk2 null mutant to serum was severely diminished at low serum concentrations indicates that the level of PKA is an important determinant of filamentous growth at low serum concentrations. The extent of germination attained at higher serum concentrations (5%) was similar in the wild-type and in the tpk2 null mutant strains suggesting that under these conditions germination was triggered through a PKA-independent pathway.

Imaging study of NGC 3372, the Carina nebula -I. UBVRIJHK photometry of Tr 14, Tr 15, Tr 16 and Car I Tapia, Mauricio Andres; Roth, Miguel; Vazquez, Ruben Angel; Feinstein, Alejandro We present the results of a large-scale imaging photometric study of the stellar population in the northern part of NGC 3372 in the UBVRIJHK bands with a wavelength coverage from 0.33 to 2.5 μm. The observations were made at Las Campanas Observatory. The optical CCD mosaics cover an area approximately of 32 × 22 arcmin2 centred between the Tr 14 and Tr 16 clusters. The survey was extended to cover 12 × 12 arcmin2 at the location of Tr 15. Near-infrared NICMOS3 mosaics covering the areas occupied by these clusters were obtained in the JHK photometric bands. By means of star counts in V, the centres and sizes of each cluster were redetermined yielding: Tr 14 (r = 264 arcsec), Tr 15 (r = 320 arcsec) and Tr 16 (r = 320 arcsec). It was confirmed that Cr 232 is not a true cluster. Multicolour optical photometry was obtained for 4152 stars. Two colour and colour-magnitude diagrams are presented and analysed for each individual cluster and compared to those of the field. We confirm the widespread variations in the dust density and also in the dust size distribution leading to widely different values of AV and reddening laws towards Tr 14 and Tr 16. No spatial patterns were found for these variations. Spectroscopic parallaxes were computed and the results are consistent with all three clusters being at a similar distance from the Sun (〈d〉 = 2.7 kpc) but the data have shown very large scatter in both AV and d. Analyses of the extinction-corrected colour-magnitude diagrams suggest ages between 3 and 60 million years for the stars in Tr 15 and between less than 1 and 6 million years for Tr 14 and Tr 16. A small number of infrared-excess stars were found in Tr 16 and Tr 14 but not in Tr 15. The distribution of stars in Tr 14 seen in the near-infrared suggests that this cluster is partially embedded in a molecular cloud. This molecular cloud extends towards the west reaching its highest density, marked by a CO peak emission, some three arcmin to the south-west of the nucleus of Tr 14. The rich ultraviolet field created by the Tr 14 stars ionizes most of the visible H II region in its vicinity and most of the radio H II region Car I. Evidence is found of ionization fronts leading into the molecular cloud, which appears to be 'wrapping' the Tr 14 cluster. Deep JHK images of the Car I region reveal the presence of an embedded stellar population illuminating a large infrared reflection nebula. It includes at least one O9-B0 star associated with an ultracompact H II region. Nebulous 2.2 μm emission from three of the mid-infrared sources in the Tr 14 region is also found.

Fouling behaviour of polyethersulfone UF membranes made with different PVP Marchese, Jose; Ponce, Mariela Leticia; Ochoa, Nelio Ariel; Prádanos, Pedro; Palacio, Laura; Hernández, Antonio Several polyethersulfone (PES) ultrafiltration membranes have been made with small quantities of polyvinyl-pyrrolidone (PVP) of different molecular weights to increase the permeability without a significant reduction in selectivity. The corresponding fouling mechanism and subsequent structural modifications have been analyzed when in contact with bovine serum albumin (BSA) and DL-histidine (DLH). It has been shown that according to the relative sizes of solute and pores of the membranes: BSA fouls the three membranes externally whereas DLH fouls them internally. Moreover, BSA fouls the non-PVP membranes faster than DLH fouls them slower, according to the action of hydrophobic and electrostatic forces acting at the working pH (4.9). The changes in structure, remaining after water rinsing, is quite similar for the three membranes and both the solutes, as obtained by a r etention test of adequate polyethylene glycols (PEGs).

Transtegumental diffusion of benzimidazole anthelmintics into Moniezia benedeni: correlation with their octanol–water partition coefficients Mottier, Maria de Lourdes; Alvarez, Luis Ignacio; Pis, Ma. Alejandra; Lanusse, Carlos Edmundo The experiments described here report on the correlation between the ex vivo diffusion of different benzimidazole (BZD) anthelmintics into the cestode parasite Moniezia benedeni, and their octanol–water partition coefficients (P.C.). The characterisation of the drug diffusion process into target parasites is relevant to understand the mechanism of drug penetration and the pharmacological activity of anthelmintic drugs. Specimens of the tapeworm M. benedeni, used as a helminth parasite model, were obtained from untreated cattle killed at the local abattoir. The collected parasites were incubated (5–210 min) with either fenbendazole (FBZ),albendazole (ABZ), ricobendazole (RBZ), oxfendazole (OFZ), mebendazole (MBZ), oxibendazole (OBZ), or thiabendazole (TBZ), in a Kreb’s Ringer Tris buffer medium at a final concentration of 5 nmol/ml. After the incubation time elapsed, samples of parasite material were chemically extracted and prepared for high performance liquid chromatography (HPLC) analysis to measure drug/metabolite concentrations. Additionally, the octanol–water P.C. for each molecule was estimated as an indicator of drug lipophilicity,using reversed phase HPLC analysis. All the incubated drugs were recovered from the tapeworms as early as 5 min post incubation. There was a high correlation (r ¼ 0:87) between drug lipophilicity, expressed as octanol–water P.C. (Log P), and drug availability within the parasite. The most lipophilic BZD compounds (FBZ, ABZ, and MBZ), with P.C. values higher than 3.7, were measured at significative higher concentrations within the tapeworm compared to those drugs with the lowest P.C. values. Considering the results from the current and previous studies, it is clear that passive diffusion is a major mechanism of BZD penetration into cestode parasites, where lipid solubility is a determinant factor influencing the diffusion of these anthelmintic molecules through the parasite tegument.

Simulation of an Industrial Packed Column for Reactive Absorption of CO2 Gómez, C.; Borio, Daniel Oscar; Schbib, Noemi Susana − The steady-state simulation of a reactive absorption column is presented. The absorber is used in a large-scale ammonia plant to remove CO2 from the process gas stream. To enhance the absorption process, high pressures and low temperatures are commonly used (T = 45-80 °C, P = 30-40 bar). At the outlet of the absorber, the CO2 content in the process gas must be reduced to less than 500 ppm (dry basis) to avoid an excessive temperature rise in the methanation reactor (downstream of the absorption section). To represent the gas-liquid system, a rigorous mathematical model based on the two-film theory is considered. The heat effects are taken into account. The behaviour of different process variables for a reference operating condition is analyzed. The influence of changes in some operating variables is evaluated.