Effects of extraction methods on the fuel characteristics and diesel engine performances of jatropha curcas biodiesel

The development of high-quality biodiesel fuel has become more relevant due to the limited reserve and environmental effects of fossil fuel. In this study, oils derived from Jatropha curcas seeds through two extraction methods (soxhlet and cold-press) were compared. The fuel characteristics investigation suggested that methyl ester derived from oil extracted with the soxhlet method has lower viscosity, higher calculated cetane index, and slightly higher sulphur content. Comparison on the fuel characteristics with biodiesel standards showed that the methyl esters still had substantial amount of methanol and water due to low temperature during transesterification. The oils were also compared for their engine performances in a diesel engine under engine rotation of 1800 to 3000 RPM by blending derived methyl ester with pure petro-diesel to create B20 biodiesel. On average, B20 from soxhlet extraction has 3.86% higher power output, 3.55% higher torque, 3.4% higher BMEP, and 5.89% lower BSFC compared to cold-press. The extraction method affects the fuel characteristics of the methyl ester and the engine performances of the B20 biodiesel

Effect of cooling methods on dimensional accuracy and surface finish of a turned titanium part

In metal cutting, the choice of cooling method influences the deformation mechanism, which is related to the dimensional accuracy and surface finish of the parts. The deformation mechanism of titanium alloys under machining conditions is known to be very different from that of commonly used industrial materials. Therefore, the effect of cooling methods on dimensional accuracy and surface finish in machining titanium is of particular interest. This paper investigates experimentally and analytically the influence of cooling method and cutting parameters on two major dimensional accuracy characteristics of a turned titanium part—diameter error and circularity, and surface finish. Data were analyzed via three methods: traditional analysis, Pareto ANOVA, and Taguchi method. The findings indicate that the cooling method has significant effect on circularity error (contribution ratio 76.75 %), moderate effect on diameter error (contribution ratio 25.00 %), and negligible effect on surface finish (contribution ratio 0.16 %)

Dynamin I phosphorylation by GSK3 controls activity-dependent bulk endocytosis of synaptic vesicles.

Glycogen synthase kinase 3 (GSK3) is a critical enzyme in neuronal physiology; however, it is not yet known whether it has any specific role in presynaptic function. We found that GSK3 phosphorylates a residue on the large GTPase dynamin I (Ser-774) both in vitro and in primary rat neuronal cultures. This was dependent on prior phosphorylation of Ser-778 by cyclin-dependent kinase 5. Using both acute inhibition with pharmacological antagonists and silencing of expression with short hairpin RNA, we found that GSK3 was specifically required for activity-dependent bulk endocytosis (ADBE) but not clathrin-mediated endocytosis. Moreover we found that the specific phosphorylation of Ser-774 on dynamin I by GSK3 was both necessary and sufficient for ADBE. These results demonstrate a presynaptic role for GSK3 and they indicate that a protein kinase signaling cascade prepares synaptic vesicles for retrieval during elevated neuronal activity

A Dynamic View of Domain-Motif Interactions

Many protein-protein interactions are mediated by domain-motif interaction, where a domain in one protein binds a short linear motif in its interacting partner. Such interactions are often involved in key cellular processes, necessitating their tight regulation. A common strategy of the cell to control protein function and interaction is by post-translational modifications of specific residues, especially phosphorylation. Indeed, there are motifs, such as SH2-binding motifs, in which motif phosphorylation is required for the domain-motif interaction. On the contrary, there are other examples where motif phosphorylation prevents the domain-motif interaction. Here we present a large-scale integrative analysis of experimental human data of domain-motif interactions and phosphorylation events, demonstrating an intriguing coupling between the two. We report such coupling for SH3, PDZ, SH2 and WW domains, where residue phosphorylation within or next to the motif is implied to be associated with switching on or off domain binding. For domains that require motif phosphorylation for binding, such as SH2 domains, we found coupled phosphorylation events other than the ones required for domain binding. Furthermore, we show that phosphorylation might function as a double switch, concurrently enabling interaction of the motif with one domain and disabling interaction with another domain. Evolutionary analysis shows that co-evolution of the motif and the proximal residues capable of phosphorylation predominates over other evolutionary scenarios, in which the motif appeared before the potentially phosphorylated residue, or vice versa. Our findings provide strengthening evidence for coupled interaction-regulation units, defined by a domain-binding motif and a phosphorylated residue

Adenylyl Cyclases 1 and 8 Initiate a Presynaptic Homeostatic Response to Ethanol Treatment

BACKGROUND:Although ethanol exerts widespread action in the brain, only recently has progress been made in understanding the specific events occurring at the synapse during ethanol exposure. Mice deficient in the calcium-stimulated adenylyl cyclases, AC1 and AC8 (DKO), demonstrate increased sedation duration and impaired phosphorylation by protein kinase A (PKA) following acute ethanol treatment. While not direct targets for ethanol, we hypothesize that these cyclases initiate a homeostatic presynaptic response by PKA to reactivate neurons from ethanol-mediated inhibition. METHODOLOGY/PRINCIPAL FINDINGS:Here, we have used phosphoproteomic techniques and identified several presynaptic proteins that are phosphorylated in the brains of wild type mice (WT) after ethanol exposure, including synapsin, a known PKA target. Phosphorylation of synapsins I and II, as well as phosphorylation of non-PKA targets, such as, eukaryotic elongation factor-2 (eEF-2) and dynamin is significantly impaired in the brains of DKO mice. This deficit is primarily driven by AC1, as AC1-deficient, but not AC8-deficient mice also demonstrate significant reductions in phosphorylation of synapsin and eEF-2 in cortical and hippocampal tissues. DKO mice have a reduced pool of functional recycling vesicles and fewer active terminals as measured by FM1-43 uptake compared to WT controls, which may be a contributing factor to the impaired presynaptic response to ethanol treatment. CONCLUSIONS/SIGNIFICANCE:These data demonstrate that calcium-stimulated AC-dependent PKA activation in the presynaptic terminal, primarily driven by AC1, is a critical event in the reactivation of neurons following ethanol-induced activity blockade

Effect of Inhibitors on Biogas Laminar Burning Velocity and Flammability Limits in Spark Ignited Premix Combustion

Abstract-Biogas is the natural byproduct of the decomposition of vegetation or animal manure, of which there are almost in exhaustable supplies in the world, and which does not contribute CO 2 or other greenhouse gases to global warming or climate change. Biogas contains 66.4% flammable gas (CH 4 ) and 33.6% inhibitors (CO 2 and N 2 ). This study focuses on the effects of inhibitors on biogas laminar burning velocity and flammability limits in spark ignited premix combustion. Spherically expanding laminar premixed flames, freely propagating from spark ignition sources in initially quiescent biogas-air mixtures, are continuously recorded by a high-speed digital camera. Initially, all the experiments in this paper were performed using inhibitorless biogas (biogas without inhibitors) at room temperature, at reduced pressure (0.5 atm) and at various equivalence ratios (ϕ) from the lower flammable limit to the upper flammable limit. The results are compared with those from biogas (containing inhibitors) flames at reduced pressure, inhibitorless biogas flames at atmospheric pressure (1 atm), and biogas flames at atmospheric pressure to emphasize the effect of inhibitors on biogas laminar burning velocity and flammability limits. Compared to an inhibitorless biogas-air mixtures, in the biogas-air mixtures, the presence of inhibitors cause a reduction in the laminar burning velocity and the flammable limits become narrower. Keyword-Biogas, Inhibitor, Laminar burning velocity, Flammability limit, Premix combustion I. INTRODUCTION Biogas is the natural byproduct of the decomposition of vegetation or animal manure, of which there are almost in exhaustible supplies in the world, and which does not contribute CO 2 or other greenhouse gases to global warming or climate change. It is, thus, eminently suitable as a green alternative to fossil fuels, which could help to reduce rising world temperatures. In addition, biogas can significantly improve rural economies, an important factor in poor developing countries. Biogas contains between 50-70% flammable gas (CH 4 ) and 30-50% inhibitors (CO 2 and N 2 ), as well as small amounts of other gases and typically has a calorific value of 21-24 MJ/m3 and is a candidate in the search and development of sustainable green fuels. Additional benefits are its practicability and low construction costs, the necessary digestion facilities can quickly, easily and cheaply be constructed by unskilled local labour. Although to date research into biogas has had good results, if biogas is to become a major source of sustainable energy for the world, both its laminar burning velocity and flammability limits, as key parameters of any combustion mixture, requires further in depth investigation Flammability levels indicate biogas's proportion of combustible gases and its limits. Gas mixtures consist of both combustibles, oxidizing and inert elements which are only combustible under certain conditions. The leanest ignitable flammable mixture is the lowest one, or the one with the smallest amount of combustible gases, likewise the richest flammable mixture has the highest flammable limit. Biogas differs from other hydrocarbon fuels in that studies have shown that the laminar burning velocity changes as a function of the equivalence ratio. The laminar burning velocity of rich biogas mixtures is lower than that of leaner ones. The laminar burning velocities of rich biogas air mixtures is less than those of lean mixtures which strengthens the finding that inhibitor gases have a greater effect on the laminar burning velocities in rich mixtures and corresponding lesser effect on lean mixtures due to the higher mole factor of these gases. This is so because the inhibitor in biogas not only dilutes the fuel mixture but also impedes the reaction as well as absorbing reaction heat which further reduces reaction rates. The effect of inhibitor is similar to that of high pressure, it raises the diffusion time and cuts short the reactant resident time or by reducing pressure when the thermal diffusivity of fuel mixtures is higher, which in turn should shorten reaction time Laminar burning velocity and flammability limits are the most important flame propagating component in spark ignited premixed combustion and as the fundamental flame propagation characteristics of biogas are stil

Effect of Inhibitors on Biogas Laminar Burning Velocity and Flammability Limits in Spark Ignited Premix Combustion

Abstract-Biogas is the natural byproduct of the decomposition of vegetation or animal manure, of which there are almost in exhaustable supplies in the world, and which does not contribute CO 2 or other greenhouse gases to global warming or climate change. Biogas contains 66.4% flammable gas (CH 4 ) and 33.6% inhibitors (CO 2 and N 2 ). This study focuses on the effects of inhibitors on biogas laminar burning velocity and flammability limits in spark ignited premix combustion. Spherically expanding laminar premixed flames, freely propagating from spark ignition sources in initially quiescent biogas-air mixtures, are continuously recorded by a high-speed digital camera. Initially, all the experiments in this paper were performed using inhibitorless biogas (biogas without inhibitors) at room temperature, at reduced pressure (0.5 atm) and at various equivalence ratios (ϕ) from the lower flammable limit to the upper flammable limit. The results are compared with those from biogas (containing inhibitors) flames at reduced pressure, inhibitorless biogas flames at atmospheric pressure (1 atm), and biogas flames at atmospheric pressure to emphasize the effect of inhibitors on biogas laminar burning velocity and flammability limits. Compared to an inhibitorless biogas-air mixtures, in the biogas-air mixtures, the presence of inhibitors cause a reduction in the laminar burning velocity and the flammable limits become narrower. Keyword-Biogas, Inhibitor, Laminar burning velocity, Flammability limit, Premix combustion I. INTRODUCTION Biogas is the natural byproduct of the decomposition of vegetation or animal manure, of which there are almost in exhaustible supplies in the world, and which does not contribute CO 2 or other greenhouse gases to global warming or climate change. It is, thus, eminently suitable as a green alternative to fossil fuels, which could help to reduce rising world temperatures. In addition, biogas can significantly improve rural economies, an important factor in poor developing countries. Biogas contains between 50-70% flammable gas (CH 4 ) and 30-50% inhibitors (CO 2 and N 2 ), as well as small amounts of other gases and typically has a calorific value of 21-24 MJ/m3 and is a candidate in the search and development of sustainable green fuels. Additional benefits are its practicability and low construction costs, the necessary digestion facilities can quickly, easily and cheaply be constructed by unskilled local labour. Although to date research into biogas has had good results, if biogas is to become a major source of sustainable energy for the world, both its laminar burning velocity and flammability limits, as key parameters of any combustion mixture, requires further in depth investigation Flammability levels indicate biogas's proportion of combustible gases and its limits. Gas mixtures consist of both combustibles, oxidizing and inert elements which are only combustible under certain conditions. The leanest ignitable flammable mixture is the lowest one, or the one with the smallest amount of combustible gases, likewise the richest flammable mixture has the highest flammable limit. Biogas differs from other hydrocarbon fuels in that studies have shown that the laminar burning velocity changes as a function of the equivalence ratio. The laminar burning velocity of rich biogas mixtures is lower than that of leaner ones. The laminar burning velocities of rich biogas air mixtures is less than those of lean mixtures which strengthens the finding that inhibitor gases have a greater effect on the laminar burning velocities in rich mixtures and corresponding lesser effect on lean mixtures due to the higher mole factor of these gases. This is so because the inhibitor in biogas not only dilutes the fuel mixture but also impedes the reaction as well as absorbing reaction heat which further reduces reaction rates. The effect of inhibitor is similar to that of high pressure, it raises the diffusion time and cuts short the reactant resident time or by reducing pressure when the thermal diffusivity of fuel mixtures is higher, which in turn should shorten reaction time Laminar burning velocity and flammability limits are the most important flame propagating component in spark ignited premixed combustion and as the fundamental flame propagation characteristics of biogas are stil