Emission of polycyclic aromatic hydrocarbons from gasohol and ethanol vehicles

The exhaust emission of the polycyclic aromatic hydrocarbons (PAHs) considered toxic to human health were investigated on two spark ignition light duty vehicles, one being gasohol (Gasohol, in Brazil, is the generic denomination for mixtures of pure gasoline plus 20-25% of anhydrous ethyl alcohol fuel (AEAF).)-fuelled and the other a flexible-fuel vehicle fuelled with hydrated ethanol. The influence of fuel type and quality, aged lubricant oil type and use of fuel additives on the formation of these compounds was tested using standardized tests identical to US FTP-75 cycle. PAH sampling and chemical analysis followed the basic recommendations of method TO-13 (United States. Environmental Protection Agency, 1999. Compendium Method TO-13A - Determination of polycyclic Aromatic hydrocarbons (PAH) in Ambient Air Using Gas Chromatography/Mass Spectrometry (CG/MS). Center for environmental research information, Cincinnati, p. 78), with the necessary modification for this particular application. Results showed that the total PAH emission factor varied from 41.9 mu g km(-1) to 612 mu g km(-1) in the gasohol vehicle, and from 11.7 mu g km(-1) to 27.4 mu g km(-1) in the ethanol-fuelled vehicle, a significant difference in favor of the ethanol vehicle. Generally, emission of light molecular weight PAHs was predominant, while high molecular weights PAHs were not detected. In terms of benzo(a)pyrene toxicity equivalence, emission factors varied from 0.00984 mu g TEQ km(-1) to 4.61 mu g TEQ km(-1) for the gasohol vehicle and from 0.0117 mu g TEQ km(-1) to 0.0218 mu g TEQ km(-1) in the ethanol vehicle. For the gasohol vehicle, results showed that the use of fuel additive causes a significant increase in the emission of naphthalene and phenanthrene at a confidence level of 90% or higher; the use of rubber solvent on gasohol showed a reduction in the emission of naphthalene and phenanthrene at the same confidence level; the use of synthetic oil instead of mineral oil also contributed significantly to a decrease in the emission of naphthalene and fluorene. In relation to the ethanol vehicle, the same factors were tested and showed no statistically significant influence on PAH emission. (c) 2008 Elsevier Ltd. All rights reserved.

Phase equilibria study of systems composed of refined babassu oil, lauric acid, ethanol, and water at 303.2 K

Deacidification of vegetable oils can be performed using liquid-liquid extraction as an alternative method to the classical chemical and physical refining processes. This paper reports experimental data for systems containing refined babassu oil, lauric acid, ethanol, and water at 303.2 K with different water mass fractions in the alcoholic solvent (0, 0.0557, 0.1045, 0.2029, and 0.2972). The dilution of solvent with water reduced the distribution coefficient values, which indicates a reduction in the loss of neutral oil. The experimental data were used to adjust the NRTL equation parameters. The global deviation between the observed and the estimated compositions was 0.0085, indicating that the model can accurately predict the behavior of the compounds at different levels of solvent hydration. (C) 2011 Elsevier Ltd. All rights reserved.

Liquid-liquid equilibria for systems composed of refined soybean oil, free fatty acids, ethanol, and water at different temperatures

Soybean oil can be deacidified by liquid-liquid extraction with ethanol. In the present paper, the liquid-liquid equilibria of systems composed of refined soybean oil, commercial linoleic acid, ethanol and water were investigated at 298.2 K. The experimental data set obtained from the present study (at 298.2 K) and the results of Mohsen-Nia et al. [1] (at 303.2 K) and Rodrigues et al. [2] (at 323.2 K) were correlated by applying the non-random two liquid (NRTL) model. The results of the present study indicated that the mutual solubility of the compounds decreased with an increase in the water content of the solvent and a decrease in the temperature of the solution. Among variables, the water content of the solvent had the strongest effect on the solubility of the components. The maximum deviation and average variance between the experimental and calculated compositions were 1.60% and 0.89%, indicating that the model could accurately predict the behavior of the compounds at different temperatures and degrees of hydration. (C) 2010 Elsevier B.V. All rights reserved.

Response surface methodology applied to the analysis of rice bran oil extraction process with ethanol

P>Vegetable oils can be extracted using ethanol as solvent. The main goal of this work was to evaluate the ethanol performance on the extraction process of rice bran oil. The influence of process variables, solvent hydration and temperature was evaluated using the response surface methodology, aiming to maximise the soluble substances and gamma-oryzanol transfer and minimise the free fatty acids extraction and the liquid content in the underflow solid. It can be noted that oil solubility in ethanol was highly affected by the water content. The free fatty acids extraction is improved by increasing the moisture content in the solvent. Regarding the gamma-oryzanol, it can be observed that its extraction is affected by temperature when low level of water is added to ethanol. On the other hand, the influence of temperature is minimised with high levels of water in the ethanol.

Effect of solvent hydration and temperature in the deacidification process of sunflower oil using ethanol

This work presents liquid-liquid experimental data for systems composed of sunflower seed oil, ethanol and water from 10 to 60 degrees C. The influence of process variables (temperature (T) and water concentration in the solvent (W)) on both the solvent content present in the raffinate (S(RP)) and extract (S(EP)) phases and the partition of free fatty acids (k(2)) was evaluated using the response surface methodology, where flash calculations were performed for each trial using the UNIQUAC equation. Water content in the solvent was the most important factor on the responses of S(EP) and k(2). Additionally, statistical analysis showed that the S(RP) was predominantly affected by temperature factor for low water content in the solvent. (c) 2009 Elsevier Ltd. All rights reserved.

Characterization of Metal and Trace Element Contents of Particulate Matter (PM10) Emitted by Vehicles Running on Brazilian FuelsHydrated Ethanol and Gasoline with 22% of Anhydrous Ethanol

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM10) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM2.5), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM10 emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

Colony dehydration and water collection by specialized caste in the leaf-cutting ant Atta sexdens rubropilosa

Social organization enables leaf-cutting ants to keep appropriate micro-ecological nest conditions for the fungus garden (their main food), eggs, larvae and adults. To maintain stability while facing changing conditions, individual ants must perceive destabilising factors and produce a proper behavioral response. We investigated behavioral responses to experimental dehydration in leaf-cutting ants to verify if task specialization exists, and to quantify the ability of ant sub-colonies for water management. Our setup consisted of fourteen sub-colonies, ten of which were randomly assigned to different levels of experimental dehydration with silica gel, whereas the remaining four were controls. The ten experimental sub-colonies were split into two groups, so that five of them had access to water. Diverse ant morphs searched for water in dehydrated colonies, but mainly a caste of small ants collected water after sources had been discovered. Size specialization for water collection was replicable in shorter experiments with three additional colonies. Ants of dehydrated colonies accumulated leaf-fragments on the nest entrance, and covering the fungus garden. Behaviors that may enhance humidity within the nests were common to all dehydration treatments. Water availability increased the life span of dehydrated colonies.

Switching control of sympathetic activity from forebrain to hindbrain in chronic dehydration

We investigated the mechanisms responsible for increased blood pressure and sympathetic nerve activity (SNA) caused by 2-3 days dehydration (DH) both in vivo and in situ preparations. In euhydrated (EH) rats, systemic application of the AT(1) receptor antagonist Losartan and subsequent pre-collicular transection (to remove the hypothalamus) significantly reduced thoracic (t) SNA. In contrast, in DH rats, Losartan, followed by pre-collicular and pontine transections, failed to reduce tSNA, whereas transection at the medulla-spinal cord junction massively reduced tSNA. In DH but not EH rats, selective inhibition of the commissural nucleus tractus solitarii (cNTS) significantly reduced tSNA. Comparable data were obtained in both in situ and in vivo (anaesthetized/conscious) rats and suggest that following chronic dehydration, the control of tSNA transfers from supra-brainstem structures (e. g. hypothalamus) to the medulla oblongata, particularly the cNTS. As microarray analysis revealed up-regulation of AP1 transcription factor JunD in the dehydrated cNTS, we tested the hypothesis that AP1 transcription factor activity is responsible for dehydration-induced functional plasticity. When AP1 activity was blocked in the cNTS using a viral vector expressing a dominant negative FosB, cNTS inactivation was ineffective. However, tSNA was decreased after pre-collicular transection, a response similar to that seen in EHrats. Thus, the dehydration-induced switch in control of tSNA from hypothalamus to cNTS seems to be mediated via activation of AP1 transcription factors in the cNTS. If AP1 activity is blocked in the cNTS during dehydration, sympathetic activity control reverts back to forebrain regions. This unique reciprocating neural structure-switching plasticity between brain centres emphasizes the multiple mechanisms available for the adaptive response to dehydration.

Ethanol-induced sensitization depends preferentially on D(1) rather than D(2) dopamine receptors

Behavioral sensitization, defined as a progressive increase in the locomotor stimulant effects elicited by repeated exposure to drugs of abuse, has been used as an animal model for drug craving in humans. The mesoaccumbens dopaminergic system has been proposed to be critically involved in this phenomenon; however, few studies have been designed to systematically investigate the effects of dopaminergic antagonists on development and expression of behavioral sensitization to ethanol in Swiss mice. We first tested the effects of D(1) antagonist SCH-23390 (0-0.03 mg/kg) or D(2) antagonist Sulpiride (0-30 mg/kg) on the locomotor responses to an acute injection of ethanol (2.0 g/kg). Results showed that all tested doses of the antagonists were effective in blocking ethanol`s stimulant effects. In another set of experiments, mice were pretreated intraperitoneally with SCH-23390 (0.01 mg/kg) or Sulpiride (10 mg/kg) 30 min before saline or ethanol injection, for 21 days. Locomotor activity was measured weekly for 20 min. Four days following this pretreatment, all mice were challenged with ethanol. Both antagonists attenuated the development of ethanol sensitization, but only SCH-23390 blocked the expression of ethanol sensitization according to this protocol. When we tested a single dose (30 min before tests) of either antagonist in mice treated chronically with ethanol, both antagonists attenuated ethanol-induced effects. The present findings demonstrate that the concomitant administration of ethanol with D(1) but not D(2) antagonist prevented the expression of ethanol sensitization, suggesting that the neuroadaptations underlying ethanol behavioral sensitization depend preferentially on D(1) receptor actions. (C) 2010 Elsevier Inc. All rights reserved.

Changes in extracellular levels of glutamate in the nucleus accumbens after ethanol-induced behavioral sensitization in adolescent and adult mice

Repeated administration of low doses of ethanol gradually increases locomotor responses to ethanol in adult Swiss mice. This phenomenon is known as behavioral sensitization. However, we have shown that adolescent Swiss mice show either behavioral tolerance or no sensitization after repeated ethanol injections. Although the mesolimbic dopamine system has been extensively implicated in behavioral sensitization, several studies have demonstrated an important role of glutamatergic transmission in this phenomenon. In addition, relatively few studies have examined the role of developmental factors in behavioral sensitization to ethanol. To examine the relationship between age differences in behavioral sensitization to ethanol and the neurochemical adaptations related to glutamate within nucleus accumbens (NAc), in vivo microdialysis was conducted in adolescent and adult Swiss mice treated with ethanol (1.8 g/kg) or saline for 15 days and subsequently challenged with an acute dose (1.8 g/kg) of ethanol 6 days later. Consistent with previous findings, only adult mice demonstrated evidence of behavioral sensitization. However, ethanol-treated adolescent mice demonstrated a 196.1 +/- 40.0% peak increase in extracellular levels of glutamate in the NAc after ethanol challenge in comparison with the basal values, whereas ethanol-treated adult mice demonstrated a 52.2 +/- 6.2% reduction in extracellular levels of glutamate in the NAc after ethanol challenge. These observations suggest an age-dependent inverse relationship between behavioral and glutamatergic responses to repeated ethanol exposure. (C) 2011 Elsevier Inc. All rights reserved.

Environmental modulation of ethanol-induced locomotor activity: Correlation with neuronal activity in distinct brain regions of adolescent and adult Swiss mice

Drug abuse is a concerning health problem in adults and has been recognized as a major problem in adolescents. induction of immediate-early genes (IEG), such as c-Fos or Egr-1, is used to identify brain areas that become activated in response to various stimuli, including addictive drugs. It is known that the environment can alter the response to drugs of abuse. Accordingly, environmental cues may trigger drug-seeking behavior when the drug is repeatedly administered in a given environment. The goal of this study was first to examine for age differences in context-dependent sensitization and then evaluate IEG expression in different brain regions. For this, groups of mice received i.p. ethanol (2.0 g/kg) or saline in the test apparatus, while other groups received the solutions in the home cage, for 15 days. One week after this treatment phase, mice were challenged with ethanol injection. Acutely, ethanol increased both locomotor activity and IEG expression in different brain regions, indistinctly, in adolescent and adult mice. However, adults exhibited a typical context-dependent behavioral sensitization following repeated ethanol treatment, while adolescent mice presented gradually smaller locomotion across treatment, when ethanol was administered in a paired regimen with environment. Conversely, ethanol-treated adolescents expressed context-independent behavioral sensitization. Overall, repeated ethanol administration desensitized IEG expression in both adolescent and adult mice, but this effect was greatest in the nucleus accumbens and prefrontal cortex of adolescents treated in the context-dependent paradigm. These results suggest developmental differences in the sensitivity to the conditioned and unconditioned locomotor effects of ethanol. (C) 2008 Elsevier B.V. All rights reserved.

Ablation of primary afferent neurons by neonatal capsaicin treatment reduces the susceptibility of the portal hypertensive gastric mucosa to ethanol-induced injury in cirrhotic rats

Primary sensory afferent neurons modulate the hyperdynamic circulation in Cirrhotic rats with portal hypertension.The stomach of cirrhotic rats is prone to damage induced by ethanol, a phenomenon associated with reduced gastric hyperemic response to acid-back diffusion. The aim of this study was to examine the impact of ablation of capsaicin-sensitive neurons and the tachykinin NK(1) receptor antagonist A5330 on the susceptibility of the portal hypertensive gastric mucosa, to ethanol-induced injury and its effects on gastric cyclooxygenase (COX) and nitric oxide synthase (NOS) mRNA expression. Capsaicin was administered to neonatal, male, Wistar rats and the animals were allowed to grow. Cirrhosis was then induced by bile duct ligation in adult rats while controls had sham operation. Ethanol-induced gastric damage was assessed using ex vivo gastric chamber experiments. Gastric blood flow was measured as well as COX/NOS mRNA expression. Topical application of ethanol produced significant gastric damage in cirrhotic rats compared to controls, which was reversed in capsaicin- and A5330-treated animals. Mean arterial and portal pressure was normalized in capsaicin-treated cirrhotic rats. Capsaicin and A5330 administration restored gastric blood flow responses to topical application of ethanol followed by acid in cirrhotic rats. Differential COX and NOS mRNA expression was noted in bile duct ligated rats relative to controls. Capsaicin treatment significantly modified gastric eNOS/iNOS/COX-2 mRNA expression in cirrhotic rats. Capsaicin-sensitive neurons modulate the susceptibility of the portal hypertensive gastric mucosa to injury induced by ethanol via tachykinin NK(1) receptors and signalling of prostaglandin and NO production/release. (c) 2008 Elsevier B.V. All rights reserved.

Ethanol consumption and pineal melatonin daily profile in rats

It is well known that melatonin participates in the regulation of many important physiological functions such as sleep-wakefulness cycle, motor coordination and neural plasticity, and cognition. However, as there are contradictory results regarding the melatonin production diurnal profile under alcohol consumption, the aim of this paper was to study the phenomenology and mechanisms of the putative modifications on the daily profile of melatonin production in rats submitted to chronic alcohol intake. The present results show that rats receiving 10% ethanol in drinking water for 35 days display an altered daily profile of melatonin production, with a phase delay and a reduction in the nocturnal peak. This can be partially explained by a loss of the daily rhythm and the 25% reduction in tryptophan hydroxylase activity and, mainly, by a phase delay in arylalkylamine N-acetyltransferase gene expression and a 70% reduction in its peak activity. Upstream in the melatonin synthesis pathway, the results showed that noradrenergic signaling is impaired as well, with a decrease in beta 1 and alpha 1 adrenergic receptors` mRNA contents and in vitro sustained loss of noradrenergic-stimulated melatonin production by glands from alcohol-treated rats. Together, these results confirm the alterations in the daily melatonin profile of alcoholic rats and suggest the possible mechanisms for the observed melatonin synthesis modification.

The potential for first-generation ethanol production from sugarcane

Ethanol production from sugarcane, mainly in Brazil, on the basis of first-generation technology (22.5 billion liters, in 2007/2008 season, in 3.4 million hectares) replaces 1% of the gasoline used in the world today and is highly competitive in economic terms with ethanol produced from other crops in the USA and Europe. In this paper we discuss the potential for sugarcane ethanol expansion from two angles: (1) productivity gains which would allow greater production in the same area and (2) geographical expansion to larger areas. The potential of first-generation technology for the production of ethanol from sugarcane is far from being exhausted. There are gains in productivity of approximately a factor of two from genetically modified varieties and a geographical expansion by a factor of ten of the present level of production in many sugar-producing countries. The replacement of 10% of the gasoline used in the world by ethanol from sugarcane seems possible before second-generation technology reaches technological maturity and possibly economic competitiveness. (C) 2009 Society of Chemical Industry and John Wiley & Sons, Ltd

Historical carbon budget of the brazilian ethanol program

This work models the carbon neutralization capacity of Brazil`s ethanol program since 1975. In addition to biofuel, we also assessed the mitigation potential of other energy products, such as, bioelectricity, and CO(2) emissions captured during fermentation of sugar cane`s juice. Finally, we projected the neutralization capacity of sugar cane`s bio-energy system over the next 32 years. The balance between several carbon stocks and flows was considered in the model, including the effects of land-use change. Our results show that the neutralization of the carbon released due to land-use change was attained only in 1992, and the maximum mitigation potential of the sugar cane sector was 128 tonnes Of CO(2) per ha in 2006. An ideal reconstitution of the deployment of the sugar cane sector, including the full exploitation of bio-electricity`s potential, plus the capture Of CO(2) released during fermentation, shows that the neutralization of land-use change emissions would have been achieved in 1988, and its mitigation potential would have been 390 tCO(2)/ha. Finally, forecasts of the sector up to 2039 shows that the mitigation potential in 2039 corresponds to 836 tCO(2)/ha, which corresponds to 5.51 kg Of CO(2) per liter of ethanol produced, or 55% above the negative emission level. (C) 2009 Elsevier Ltd. All rights reserved.