Biodiesel Production from High Free Fatty Acid-Content Oils: Experimental Investigation of the Pretreatment Step

AbstractBiodiesel has the potential to become a suitable substitute for diesel fuel in the future. However, the reduction of production costs and finding a permanent oil source have remained the two main concerns for this green fuel. The production of biodiesel from acid oils is one of the ways to reduce biodiesel production costs. In addition, high free fatty acid oils are almost never categorized as edible oils. Consequently, this new material has a more reliable margin in debates concerning the security of food, compared to other oils considered in biodiesel production. By considering these important aspects of biodiesel production technology, this study investigates the pretreatment step of biodiesel production from acid oils. In this work, an oil with high free fatty acid content is selected and the main parameters in the biodiesel production reaction are investigated experimentally. The effects of methanol-to-oil ratio (in the range of 0.2 to 1.2 v/v), the amount of catalyst (in the range of 0.5 to 6% v/v) and time (in the range of 20 to 120min) on the progress of the reaction are studied

Effects of air pollution on public and private health expenditures in Iran: A time series study (1972-2014)

Objectives: Environmental pollution is a negative consequence of the development process, and many countries are grappling with this phenomenon. As a developing country, Iran is not exempt from this rule, and Iran pays huge expenditures for the consequences of pollution. The aim of this study was to analyze the long- and short-run impact of air pollution, along with other health indicators, on private and public health expenditures. Methods: This study was an applied and developmental study. Autoregressive distributed lag estimating models were used for the period of 1972 to 2014. In order to determine the co-integration between health expenditures and the infant mortality rate, fertility rate, per capita income, and pollution, we used the Wald test in Microfit version 4.1. We then used Eviews version 8 to evaluate the stationarity of the variables and to estimate the long- and short-run relationships. Results: Long-run air pollution had a positive and significant effect on health expenditures, so that a 1.00 increase in the index of carbon dioxide led to an increase of 3.32 and 1.16 in public and private health expenditures, respectively. Air pollution also had a greater impact on health expenditures in the long term than in the short term. Conclusions: The findings of this study indicate that among the factors affecting health expenditures, environmental quality and contaminants played the most important role. Therefore, in order to reduce the financial burden of health expenditures in Iran, it is essential to reduce air pollution by enacting and implementing laws that protect the environment. Copyright © 2018 The Korean Society for Preventive Medicine

Association between the number of coadministered P-glycoprotein inhibitors and serum digoxin levels in patients on therapeutic drug monitoring

BACKGROUND: The ABC transporter P-glycoprotein (P-gp) is recognized as a site for drug-drug interactions and provides a mechanistic explanation for clinically relevant pharmacokinetic interactions with digoxin. The question of whether several P-gp inhibitors may have additive effects has not yet been addressed. METHODS: We evaluated the effects on serum concentrations of digoxin (S-digoxin) in 618 patients undergoing therapeutic drug monitoring. P-gp inhibitors were classified as Class I, with a known effect on digoxin kinetics, or Class II, showing inhibition in vitro but no documented effect on digoxin kinetics in humans. Mean S-digoxin values were compared between groups of patients with different numbers of coadministered P-gp inhibitors by a univariate and a multivariate model, including the potential covariates age, sex, digoxin dose and total number of prescribed drugs. RESULTS: A large proportion (47%) of the digoxin patients undergoing therapeutic drug monitoring had one or more P-gp inhibitor prescribed. In both univariate and multivariate analysis, S-digoxin increased in a stepwise fashion according to the number of coadministered P-gp inhibitors (all P values < 0.01 compared with no P-gp inhibitor). In multivariate analysis, S-digoxin levels were 1.26 ± 0.04, 1.51 ± 0.05, 1.59 ± 0.08 and 2.00 ± 0.25 nmol/L for zero, one, two and three P-gp inhibitors, respectively. The results were even more pronounced when we analyzed only Class I P-gp inhibitors (1.65 ± 0.07 for one and 1.83 ± 0.07 nmol/L for two). CONCLUSIONS: Polypharmacy may lead to multiple drug-drug interactions at the same site, in this case P-gp. The S-digoxin levels increased in a stepwise fashion with an increasing number of coadministered P-gp inhibitors in patients taking P-gp inhibitors and digoxin concomitantly. As coadministration of digoxin and P-gp inhibitors is common, it is important to increase awareness about P-gp interactions among prescribing clinicians

Inhibitive effect of sodium (E)-4-(4-nitrobenzylidenamino) benzoate on the corrosion of some metals in sodium chloride solution

The inhibition performance of a novel anionic carboxylic Schiff base, sodium (E)-4-(4-nitrobenzylideneamino)benzoate (SNBB), was investigated for various metals, namely low carbon steel F111, pure iron and copper, in neutral 10 mM NaCl solution. Potentiodynamic polarization, scanning vibrating electrode technique (SVET), quantum chemical (QC) calculation, and molecular dynamics (MD) simulation were employed. The potentiodynamic polarization data showed that SNBB acts as an effective corrosion inhibitor for both iron and F111 steel, but it is not effective for the copper. In situ spatially-resolved SVET maps evidenced a major change in surface reactivity for Fe and F111 steel immersed in 10 mM aqueous solution in the absence and in the presence of SNBB. Featureless ionic current density distributions were recorded in the presence of SNBB at both their spontaneous open circuit potential (OCP) and under mild anodic polarization conditions, while major ionic flows were monitored above the metals in the absence of SNBB. On the basis of computer simulations, it is proposed that SNBB produces a stable chelate film on iron and steel surfaces that accounts for the good corrosion inhibition efficiency observed. The different inhibition efficiencies of SNBB molecules on the iron and copper was attributed to the special chemical structure of SNBB molecule and its different chelation ability with the released metal ions on the metal surface. The QC calculations also confirmed the high corrosion inhibition efficiency of SNBB. The MD simulation indicated higher binding energy of SNBB on iron surface compared to that of copper surface. The interaction mode of SNBB on iron and F111 steel surfaces corresponds to a mixed chemical and physical adsorption, and it obeys the Langmuir isother

Motivation types and mental health of UK hospitality workers.

The primary purposes of this study were to (i) assess levels of different types of work motivation in a sample of UK hospitality workers and make a cross-cultural comparison with Chinese counterparts and (ii) identify how work motivation and shame-based attitudes towards mental health explain the variance in mental health problems in UK hospitality workers. One hundred three UK hospitality workers completed self-report measures, and correlation and multiple regression analyses were conducted to identify significant relationships. Findings demonstrate that internal and external motivation levels were higher in UK versus Chinese hospitality workers. Furthermore, external motivation was more significantly associated with shame and mental health problems compared to internal motivation. Motivation accounted for 34–50% of mental health problems. This is the first study to explore the relationship between motivation, shame, and mental health in UK hospitality workers. Findings suggest that augmenting internal motivation may be a novel means of addressing mental health problems in this worker population.N/

On the phenomenon of Double Retrograde Vaporization: Within a study on Supercritical Deterpenation of Orange Oils with Ethane

Materials for Energy Conversion and StorageApplied Science

Vapor-liquid equilibria of the binary system 1,5-hexadiene + allyl chloride

Knowledge of accurate vapor–liquid equilibrium data for mixtures of allyl chloride and 1,5-hexadiene is important for several industrial purposes. The bubble points of binary mixtures of allyl chloride and 1,5-hexadiene have been measured experimentally using a synthetic method. Measurements were carried over concentrations ranging from (0 to 1) mol % of allyl chloride. The vapor–liquid equilibrium is presented at temperatures ranging from (25 to 100) °C. Within this temperature range, bubble-point pressures up to 5 bar were observed. The experimental results indicated that, as the concentration of allyl chloride increases in the mixture, higher pressures are necessary for a complete dissolution of the two components. In addition, solubility pressures increase as temperature increases for a mixture of fixed compositio

Understanding temperature dependency of hydrogen solubility in ionic liquids, including experimental data in [bmim][Tf2N]

Previously unavailable high-pressure solubility data of hydrogen in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide has been measured experimentally up to temperatures and pressures of 450 K and 15 MPa, respectively. In contrast to CO2 solubility, H2 tends to dissolve better in the ionic liquid at higher temperatures. This "inverse" temperature effect has been studied from a thermodynamic perspective and the underlying reason for this effect is explained. It is shown that the negative P-T slope is not limited to this particular binary mixture, but is the typical behavior in most, if not all, H2 + ionic liquid systems. However, there is a certain range of temperatures, pressures, and concentrations in which this phenomenon occurs. By predicting the Scott-van Konynenburg phase diagram for systems of H2 + ionic liquids to be of type III, it is shown how and why the solubility increases with temperature in some regions, but decreases in other