Production of FAME from acid oil,a by-product of vegetable oil refining

Simple alkyl FA esters have numerous uses, including serving as biodiesel, a fuel for compression ignition (diesel) engines. The use of acid-catalyzed esterification for the synthesis of FAME from acid oil, a by-product of edible vegetable oil refining that is produced from soapstock, was investigated. Soybean acid oil contained 59.3 wt% FFA, 28.0 wt% TAG, 4.4 wt% DAG, and less than 1% MAG. Maximum esterification occurred at 65°C and 26 h reaction at a molar ratio of total FA/methanol/sulfuric acid of 1∶15∶1.5. Residual unreacted species under these conditions, as a fraction of their content in unesterified acid oil, were FFA, 6.6%; TAG, 5.8%; and DAG, 2.6%. This corresponds to estimated concentrations of FFA, 3.2%; TAG, 1.3%; and DAG, 0.2%, on a mass basis, in the ester product. In an alternative approach, the acylglycerol species in soapstock were saponified prior to acidulation. High-acid (HA) acid oil made from this saponified soapstock had an FFA content of 96.2 wt% and no detectable TAG, DAG, or MAG. Optimal esterification conditions for HA acid oil at 65°C were a mole ratio of FFA/methanol/acid of 1∶1.8∶0.17, and 14 h incubation. FAME recovery under these conditions was 89% of theoretical, and the residual unesterified FFA content was approximately 20 mg/g. This was reduced to 3.5 mg/g, below the maximum FFA level allowed for biodiesel, by washing with NaCl, NaHCO₃, and Ca(OH)₂ solutions. Alternatively, by subjecting the unwashed ester layer to a second esterification, the FFA level was reduced to less than 2 mg/g. The acid value of this material exceeded the maximum allowed for biodiesel, but was reduced to an acceptable value by a brief wash with 0.5 N NaOH.     

Cast Iron Inoculation Enhanced by Supplementary Oxy-sulfides Forming Elements

Inoculation is one of the most important metallurgical treatments applied to the molten cast iron immediately prior to casting, to promote solidification without excessive eutectic undercooling, which favors carbides formation usually with undesirable graphite morphologies. The paper focused on the separate addition of an inoculant enhancer alloy [S, O, oxy-sulfides forming elements] with a conventional Ca-FeSi alloy, in the production of gray and ductile cast irons. Carbides formation tendency decreased with improved graphite characteristics as an effect of the [Ca-FeSi + Enhancer] inoculation combination, when compared to other Ca/Ca, Ba/Ca, RE-FeSi alloy treatments. Adding an inoculant enhancer greatly enhances inoculation, lowers inoculant consumption up to 50% or more and avoids the need to use more costly inoculants, such as a rare earth bearing alloy. The Inoculation Specific Factor [ISF] was developed as a means to more realistically measure inoculant treatment efficiency. It compares the ratio between the improved characteristic level and total inoculant consumption for this effect. Addition of any of the commercial inoculants plus the inoculant enhancer offered outstanding inoculation power [increased ISF] even at higher solidification cooling rates, even though the total enhancer addition was at a small fraction of the amount of commercial inoculant used.     

Primary vacuum standard for UHV range — Standing experience and present problems

Accurate calibrations of gauges to ever lower pressures (higher vacuum) are increasingly becoming necessary. The calibrations over the entire ultra high vacuum (UHV) range i.e. up to 10⁻¹⁰ Pa are already sometimes demanded by the users of vacuum measuring devices. Standards covering part of this range are available in some national metrological laboratories while primary standards covering the entire UHV range are under development. However, the most suitable principle of the primary standard for generating such a low pressure is still not clear. In spite of some attempts during the last century no sufficiently accurate absolute (“calibration-free”) gauge for high vacuum (HV) and UHV ranges has been developed to date. Apparatuses for generating gas pressure in a dynamic flow control method will continue to be used as primary standards for the UHV range, but, by virtue of technical difficulties, the equilibrium (Maxwellian velocity distribution) will be severely disturbed during the process of pressure generation that the pressure in the chamber will not be defined as a simple scalar quantity. This principal problem must be solved first by the development of a primary UHV standard. Another serious problem in the design of an apparatusfor generating controlled pressures on the order of 10⁻¹⁰ Pa requires the uncontrolled changes of gas pressure to 10⁻¹² Pa or lower. Hence an extremely high vacuum (XHV) apparatus must be used in which the requirements concerning the pumps and the outgassing rate from the materials are kept very strict.     

索尼DSC-TX7c＆DSC-W350双响炮

当我们即将迎来喜气洋洋的春节时，逐渐增多的室外活动和朋友聚会几乎又开始占满我们的休息时间。DC，尤其是随身携带的卡片机型肯定成为了记录2010年春天的必备之物。     

The effects of vitamin E and selenium intake on oxidative stress and plasma lipids in hamsters fed fish oil

The aim of the present work was to test the effects of large-dose supplementation of vitamin E (Vit E) and selenium (Se), either singly or in combination, on fish oil (FO)-induced tissue lipid peroxidation and hyperlipidemia. The supplementation of Se has been shown to lower blood cholesterol and increase tissue concentrations of the antioxidant glutathione (GSH); however, the effects of Se supplementation, either alone or in combination with supplemental Vit E, on FO-induced oxidative stress and hyperlipidemia have not been studied. Male Syrian hamsters received FO-based diets that contained 14.3 wt% fat and 0.46 wt% cholesterol supplemented with Vit E (129 IU d-α-tocopheryl acetate/kg diet) and/or Se (3.4 ppm as sodium selenate) or that contained basal requirements of both nutrients. The cardiac tissue of hamsters fed supplemental Se showed increased concentrations of lipid hydroperoxides (LPO) but decreased oxidized glutathione (GSSG) concentrations. The higher concentrations of LPO in the hearts of Se-supplemented hamsters were not lowered with concurrent Vit E supplementation. In the liver, Se supplementation was associated with higher Se-dependent glutathione peroxidase activity and an increase in the GSH/GSSG ratio, whereas a lower hepatic non-Se-dependent glutathione peroxidase activity was seen with Vit E supplementation. Supplemental intake of Se was associated with lower plasma concentrations of total cholesterol and low density lipoprotein cholesterol plus very low density lipoprotein cholesterol. In view of the pro-oxidative effects of Se supplementation on cardiac tissue, a cautionary approach needs to be taken regarding the plasma lipid-lowering properties of supplemental Se.     

Associative memory with dynamic synapses

We have examined a role of dynamic synapses in the stochastic Hopfield-like network behavior. Our results demonstrate an appearance of a novel phase characterized by quick transitions from one memory state to another. The network is able to retrieve memorized patterns corresponding to classical ferromagnetic states but switches between memorized patterns with an intermittent type of behavior. This phenomenon might reflect the flexibility of real neural systems and their readiness to receive and respond to novel and changing external stimuli.     

How do practitioners use conceptual modeling in practice?

Much research has been devoted over the years to investigating and advancing the techniques and tools used by analysts when they model. As opposed to what academics, software providers and their resellers promote as should be happening, the aim of this research was to determine whether practitioners still embraced conceptual modeling seriously. In addition, what are the most popular techniques and tools used for conceptual modeling? What are the major purposes for which conceptual modeling is used? The study found that the top six most frequently used modeling techniques and methods were ER diagramming, data flow diagramming, systems flowcharting, workflow modeling, UML, and structured charts. Modeling technique use was found to decrease significantly from smaller to medium-sized organizations, but then to increase significantly in larger organizations (proxying for large, complex projects). Technique use was also found to significantly follow an inverted U-shaped curve, contrary to some prior explanations. Additionally, an important contribution of this study was the identification of the factors that uniquely influence the decision of analysts to continue to use modeling, viz., communication (using diagrams) to/from stakeholders, internal knowledge (lack of) of techniques, user expectations management, understanding models’ integration into the business, and tool/software deficiencies. The highest ranked purposes for which modeling was undertaken were database design and management, business process documentation, business process improvement, and software development.     

Combining Generative and Discriminative Models in a Framework for Articulated Pose Estimation

We develop a method for the estimation of articulated pose, such as that of the human body or the human hand, from a single (monocular) image. Pose estimation is formulated as a statistical inference problem, where the goal is to find a posterior probability distribution over poses as well as a maximum a posteriori (MAP) estimate. The method combines two modeling approaches, one discriminative and the other generative. The discriminative model consists of a set of mapping functions that are constructed automatically from a labeled training set of body poses and their respective image features. The discriminative formulation allows for modeling ambiguous, one-to-many mappings (through the use of multi-modal distributions) that may yield multiple valid articulated pose hypotheses from a single image. The generative model is defined in terms of a computer graphics rendering of poses. While the generative model offers an accurate way to relate observed (image features) and hidden (body pose) random variables, it is difficult to use it directly in pose estimation, since inference is computationally intractable. In contrast, inference with the discriminative model is tractable, but considerably less accurate for the problem of interest. A combined discriminative/generative formulation is derived that leverages the complimentary strengths of both models in a principled framework for articulated pose inference. Two efficient MAP pose estimation algorithms are derived from this formulation; the first is deterministic and the second non-deterministic. Performance of the framework is quantitatively evaluated in estimating articulated pose of both the human hand and human body. Most of this work was done while the first author was with Boston University.