Experimental and predicted vapour-liquid equilibrium of the binary mixtures n-heptane + chlorobutane isomers

The study of the isothermal vapour-liquid equilibrium (VLE) of the binary mixtures n-heptane plus chlorobutane isomers (1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane or 2-chloro-2-methylpropane) at three different temperatures, T = 288.15, 298.15 and 308.15 K, is presented in this contribution. The experimental results were correlated using Wilson equation and the thermodynamic consistency of the data was checked by the van Ness method. Furthermore, two different methods have been used to predict the phase equilibrium in isothermal conditions: a pure group contribution method (modified-UNIFAC) and a group contribution equation of state (VTPR)

Thermophysical study of the binary mixtures of N, N-dimethylacetamide with 1-propanol and 1-butanol

Several thermophysical properties such as densities, p, speeds of sound, u, refractive indices, nD, and kinematic viscosities, v, have been measured for the binary mixtures of N, N-Dimethylacetamide with 1-propanol and 1-butanol over the entire range of composition, at the temperatures (283.15, 298.15 and 313.15) K and at atmospheric pressure p = 0.1 MPa. From these experimental data, excess molar volumes, VE, excess isentropic compressibilities, ?S E , refractive index deviations, ?nD, and viscosity deviations, ??, were calculated. Then, correlated with the Redlich-Kister equation and the corresponding parameters were drived. The results obtained, were discussed in terms of structural effects and specific molecular interactions, and the influence of the alkanol chain length was also considered

Toxic effects of methoxychlor on the episodic prolactin secretory pattern: Possible mediated effects of nitric oxide production

BACKGROUND: This work addresses the issue of whether methoxychlor (MTX) exposure may modify the ultradian secretion of prolactin through changes in the synthesis of nitric oxide (NO) induced by N(ω)-nitro-L-arginine methyl ester (L-NAME) in the hypothalamic-pituitary axis. Associated changes in dopamine (DA) content in the anterior (AH), mediobasal (MBH) and posterior hypothalamus (PH) and median eminence (ME) were evaluated. METHODS: Two groups of animals (MTX and MTX+L-NAME treated) received subcutaneous (sc) injections of MTX at a dose of 25 mg/kg/day for one month. The other two groups of animals (control and L-NAME treated) received sc vehicle injections (0.5 mL/day of sesame oil), during the same period of time to be used as controls. Forty hours before the day of the experiment, animals were anaesthetized with intrapritoneal injections of 2.5% tribromoethanol in saline and atrial cannulas were implanted through the external jugular vein. Plasma was continuously extracted in Hamilton syringes coupled to a peristaltic bomb in tubes containing phosphate-gelatine buffer (to increase viscosity). The plasma was obtained by decantation and kept every 7 minutes for the measurement of plasma prolactin levels through a specific radioimmnunoassay and DA concentration by high-pressure liquid chromatography (HPLC). RESULTS: Prolactin release in animals from all experimental groups analyzed was episodic. Mean plasma prolactin levels during the bleeding period, and the absolute pulse amplitude were increased after MTX or N(ω)-nitro-L-arginine methyl ester (L-NAME) administration. However MTX and L-NAME did not modify any other parameter studied with the exception of relative pulse amplitude in MTX treated rats. L-NAME administration to rats treated with the pesticide reduced mean plasma prolactin levels and the absolute amplitude of prolactin peaks. Peak duration, frequency and relative amplitude of prolactin peaks were not changed in the group of rats treated with MTX plus L-NAME as compared to either control or MTX treated rats. Whereas MTX decreased DA content in the ME and increased it in the AH, its content did not change in the MBH or PH, as compared to the values found in controls. Also, L-NAME administration decreased DA content in the ME as compared to controls. However, L- NAME administration to MTX exposed rats, markedly increased DA content in the ME as compared to either MTX treated or control rats. L-NAME administration increased DA content in the AH as compared to the values found in non-treated rats. However L-NAME administration to MTX exposed rats did not modify DA content as compared to either MTX treated or control rats. L-NAME administration did not modify DA content at the MBH nor in saline treated nor in MTX treated rats. However, the values of DA in the MBH in MTX plus L-NAME treated animals were statistically decreased as compared to L-NAME treated rats. In the PH, L-NAME administration increased DA content as compared to the values found in non-treated animals. L-NAME administration to MTX exposed rats also increased DA content as compared to either MTX treated or control rats. CONCLUSION: The results suggest the existence of an interaction between MTX and L-NAME in the modulation of the ultradian prolactin secretion at the pituitary levels. The possibility of an indirect effect mediated by changes in DA content at the ME requires further examination

Dialogues on nature, class and gender: Revisiting socio-ecological reproduction in past organic advanced agriculture (Sentmenat, Catalonia, 1850)

The concept of socio-ecological reproduction allows linking some fundamental approaches and methods of Ecological, Feminist and Sraffian Economics. By accounting reproductive flows we highlight the material and time efforts required to maintain ecological funds (i.e. soil fertility and livestock) and social funds (i.e. labour force) of farm systems, as well as the role of social appropriation of the surplus that went beyond them in preindustrial class structures. Through the methodology proposed to estimate time, energy, nutrients and cash balances at household level we can infer relevant insights in terms of social organisation of labour and social distribution of produce in past organic advanced agricultures. Results show that the productive capacity of farmland and labour were quite similar across farms, while the farmland hoarding exerted by a wealthier ruling class defined the unequal distribution of produce. The match between subsistence needs and wages shows that nearly the whole potential surplus per labour unit was extracted. Dependence on reproducible funds implied the reinvestment of large amounts of renewable flows that constrained the amount of surplus appropriable. Finally, we deem that technical change and increase of total produce along socio-ecological transitions might have been affected by the social class structure of preindustrial societies

Condició Física, Salut i Emocions

Postgrau en Educació Emocional i Benestar, Facultat de Pedagogia, Departament de Mètodes d’Investigació i Diagnòstic en Educació, Universitat de Barcelona, curs: 2016-2017, Tutora: Núria Pérez Escod

Beyond Chayanov: A sustainable agroecological farm reproductive analysis of peasant domestic units and rural communities (Sentmenat; Catalonia, 1860)

We present a Sustainable Agroecological Farm Reproduction Analysis that links two methodologies kept separated so far: Optimization Modelling, and Social Metabolism accounting of the biophysical turnover from a fund-flow approach. This socio-agro-ecological model combines two scales, at farm-gate and municipal levels, and formalizes all relevant flows interlinking three living funds that have to be reproduced over time: the domestic unit, livestock and soil fertility. From the requirements and capacities of each fund (constraints), we run the model under different scenarios (objective functions) to see the different configurations that the landscape structure and the flow patterns can take (variables), ensuring the reproducibility of funds. By changing the objectives we obtain an intensive optimum that minimizes the land required; an extensive optimum that minimizes labour; and a monetary optimum that maximizes a prevailing cash crop. The model is applied to a past advanced organic farming of a Catalan village c.1860 to generate a set of counterfactual scenarios that, confronted with historical data, help to reveal how institutional settings and landownership inequality played a role in maintaining the real socio-agro-ecological structure away from these optima, and the existing potential of possible eco-functional intensification practices aimed at reducing the land cost of agrarian sustainability

Wettability control on microstructured polypropylene surfaces by means of O2 plasma

Durable and wear resistant polypropylene surfaces with static contact angle (SCA) above 140° have been fabricated using standard photolithographic process and O2 plasma etching followed by thermal annealing at 100 °C. This microfabrication process leads to a hierarchical topography derived from the patterned microstructures and the sub-micron roughness caused by plasma. Hydrophobicity (SCA up to 145°) remained over 14 months after fabrication. This wetting behavior is attributed to the combination of the periodic array of micro-sized pillars with low aspect-ratio and the submicron roughness caused by O2 plasma

Highly sensitive SERS quantification of organophosphorous chemical warfare agents: A major step towards the real time sensing in the gas phase

A surface-enhanced Raman scattering (SERS)-based sensor was developed for the label-free real-time gas phase detection of dimethyl methylphosphonate (DMMP); a surrogate molecule of the G-series nerve agents which are of particular concern due to its extreme toxicity, persistence and previous deployment. The SERS platform was designed using simple elements (Au nano-particles) coated with a citrate layer, and a self-assembly procedure that yields near- optimum distances among the nanoparticles. The citrate coating acts as an effective trap of the target molecules on the immediate vicinity of the Au nanoparticle surface under ambient conditions by reversible hydrogen bonding type interactions. For the first time, we have been able to detect sub-ppm concentrations of DMMP in gas phase (130 parts-per-billion), as might be found on potential emergency scenarios. The high sensitivity, simple preparation and reusability of the SERS platforms developed in this work open up the way for immediate detection of chemical warfare agents in realistic scenarios