Steel-Corrosion Inhibitors Derived from Soybean Oil

Soybean oil derivatives containing a Schiff-base (SOS-B) were prepared and evaluated as microbial corrosion inhibitors against sulfate-reducing bacteria using the gram-positive Desulfosporosinus orientis bacteria as a representative bacterium. These SOS-B compounds were also found to be excellent inhibitors against acidic corrosion of carbon steel. These soybean oil derivatives were prepared by ozonation of soybean oil to yield aldehyde functional intermediates which were then reacted with benzylamine to produce a mixture of imine functional triglycerides and linear compounds. The structure of these soy-based derivatives was confirmed by FTIR and NMR. It was found that the addition of these SOS-B compounds to D. orientis culture provided a complete inhibition of this bacterium. Furthermore, almost no corrosion of carbon steel panels was observed when the panels were aged in 2N HCl solution containing 10 ppm of these SOS-B compounds.     

Application of a multiple-trait, multiple-country genetic evaluation model for female fertility traits

The need to implement a method that can handle multiple traits per country in international genetic evaluations is evident. Today, many countries have implemented multiple-trait national genetic evaluations and they may expect to have their traits simultaneously analyzed in international genetic evaluations. Traits from the same country are residually correlated and the method currently in use, single-trait multiple across-country evaluation (ST-MACE), cannot handle nonzero residual correlations. Therefore, multiple-trait, multiple across-country evaluation (MT-MACE) was proposed to handle several traits from the same country simultaneously. To test the robustness of MT-MACE on real data, female fertility was chosen as a complex trait with low heritability. Data from 7 Holstein populations, 3 with 2 traits and 4 with 1 trait, were used. The differences in the estimated genetic correlations by MT-MACE and the single ST-MACE analysis (average absolute deviation of 0.064) were due to the bias of considering several traits from the same country in the ST-MACE analysis. However, the differences between the estimated genetic correlations by MT-MACE and multiple ST-MACE analyses avoiding more than one trait per country in each analysis (average absolute deviation of 0.066) were due to the lack of analysis of the correlated traits from the same country together and using the reported within-country genetic correlations. Applying MT-MACE resulted in reliability gain in international genetic evaluations, which was different from trait to trait and from bull to bull. The average reliability gain by MT-MACE over ST-MACE was 3.0 points for domestic bulls and 6.3 points for foreign bulls. Even countries with 1 trait benefited from the joint analysis of traits from the 2-trait countries. Another superiority of MT-MACE over ST-MACE is that the bulls that do not have national genetic evaluation for some traits from multiple trait countries will receive international genetic evaluations for those traits. Rank correlations were high between ST-MACE and MT-MACE when considering all bulls. However, the situation was different for the top 100 bulls. Simultaneous analysis of traits from the same country affected bull ranks, especially for top 100 bulls. Multi-trait MACE is a recommendable and robust method for international genetic evaluations and is appropriate for handling multiple traits per country, which can increase the reliability of international genetic evaluations.     

Yellow dextrins: Evaluating changes in structure and colour during processing

The preparation of a yellow dextrin is thoroughly characterized during different stages of its production process with a SEC system equipped with four detectors (light scattering, viscosity, UV and RI). With this system, also referred to as SEC‐4D, it was shown that the changes in characteristics are only in line with initial expectations up to 5 h after initiation of the reaction. After 5 h, changes in molar mass, intrinsic viscosity and colour point to the presence of significantly different structures. The combined results of the SEC‐4D measurements indicate the formation of aggregate like structures made of small starch fragments which are intensely coloured and physically linked. The obtained results also indicate that the aggregate like structures are probably still susceptible to repolymerization and transglycosylation. The newly derived parameter YI‐400 nm played an important role in defining a plausible cause for the observed changes in characteristics.     

Palladium‐Catalyzed Oxidative sp2 C?H Bond Acylation with Aldehydes

An efficient method was developed for the direct acylation of arene sp² C H bonds with aldehydes using palladium acetate as catalyst and peroxide as oxidant. The solvent‐free oxidative acylation reaction assisted by a pyridine directing group provides an easy access to aromatic, aliphatic, and optical active ketones.     

Workers Make the Queens in <Emphasis Type="Italic">Melipona</Emphasis> Bees: Identification of Geraniol as a Caste Determining Compound from Labial Glands of Nurse Bees

Reproductive division of labor in advanced eusocial honey bees and stingless bees is based on the ability of totipotent female larvae to develop into either workers or queens. In nearly all species, caste is determined by larval nutrition. However, the mechanism that triggers queen development in Melipona bees is still unresolved. Several hypotheses have been proposed, ranging from the proximate (a genetic determination of caste development) to the ultimate (a model in which larvae have complete control over their own caste fate). Here, we showed that the addition of geraniol, the main compound in labial gland secretions of nurse workers, to the larval food significantly increases the number of larvae that develop into queens. Interestingly, the proportion of queens in treated brood exactly matched the value (25%) predicted by the two-locus, two-allele model of genetic queen determination, in which only females that are heterozygous at both loci are capable of developing into queens. We conclude that labial gland secretions, added to the food of some cells by nurse bees, trigger queen development, provided that the larvae are genetically predisposed towards this developmental pathway. In Melipona beecheii, geraniol acts as a primer pheromone representing the first caste determination substance identified to date.     

Model-based,thermo-physical optimisation for high olefin yield in steam cracking reactors

The steam cracking practice seems to have reached a stage of maturity which makes it increasingly difficult to improve ethylene yield. In order to determine if there is still scope for yield improvements it is helpful to know what the optimal reaction conditions for the steam cracking process are. This work presents a model-based synthesis approach that enables to determine the optimal thermal and physical reaction conditions for a particular feed, maximising olefin yield. A distributive reaction-mixing synthesis model has been combined with an industrially proven large kinetic scheme, SPYRO^®, which contains over 7000 reactions between 218 molecular and 27 radical species. The model combination allows optimising the following degrees of freedom with respect to olefin yield: feed distribution, product removal, macro-mixing, along a reaction volume coordinate. The reaction temperature upper limit is put at 1300 K, exceeding the current (metallurgical) bound by 100 K. For the cracking of ethane a linear-concave unconstrained temperature profile with a maximum temperature of ∼1260 K proves optimal which is lower than allowed while all ethane should be supplied at the entrance of the reaction volume. For propane and heavier feedstocks an isothermal profile at the upper temperature bound, with dips at the beginning and the middle of the reaction coordinate is optimal, while distribution of the hydrocarbon feed along the reactor coordinate results in higher yields. The theoretical maximum achievable ethylene yield for ethane cracking is found to be 66.8 wt% while in conventional cracking typically 55 wt% is considered to be the maximum value. This optimum is constrained by the pressure which is at its lower bound. The resulting residence time is in the same order as with current technology for ethane cracking. For the more heavy feedstocks these times are one order of magnitude smaller which will be a challenge for designing.     

Influence of elevated pressure and particle lyophobicity on hydrodynamics and gas–liquid mass transfer in slurry bubble columns

This article reports on the influence of elevated pressure and catalyst particle lyophobicity at particle concentrations up to 3 vol % on the hydrodynamics and the gas‐to‐liquid mass transfer in a slurry bubble column. The study was done with demineralized water (aqueous phase) and Isopar‐M oil (organic phase) slurries in a 0.15 m internal diameter bubble column operated at pressures ranging from 0.1 to 1.3 MPa. The overall gas hold‐up, the flow regime transition point, the average large bubble diameter, and the centerline liquid velocity were measured along with the gas–liquid mass transfer coefficient. The gas hold‐up and the flow regime transition point are not influenced by the presence of lyophilic particles. Lyophobic particles shift the regime transition to a higher gas velocity and cause foam formation. Increasing operating pressure significantly increases the gas hold‐up and the regime transition velocity, irrespective of the particle lyophobicity. The gas–liquid mass transfer coefficient is proportional to the gas hold‐up for all investigated slurries and is not affected by the particle lyophobicity, the particle concentration, and the operating pressure. A correlation is presented to estimate the gas–liquid mass transfer coefficient as a function of the measured gas hold‐up: $k_{\rm l}a_{\rm l}/\varepsilon_{\rm g} = 3.0 \sqrt{Du_{\rm b}/d_{\rm b}^3}\;{\rm s}^{-1}$ . © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Design, performance, and limitations of fibers for cladding-pumped Raman lasers

In this paper, we present basic design rules for double-clad fibers that enable efficient 1st-Stokes operation of cladding-pumped fiber Raman devices. Limiting factors that we treat include unwanted 2nd-Stokes generation, material damage in the core, pump pulse dispersion, inner-cladding NA, background loss, pulse shape and pump noise. With a well-designed fiber, we calculate that a pump-to-signal brightness enhancement of over 2000 is possible, with certain pump parameters. On experimental work, we report a 100 W cladding-pumped fiber Raman laser at 1120 nm. Furthermore, a double-clad Raman fiber with large-mode area, ～40 μm core diameter, pumped by a Q-switched Nd:YAG laser is used to generate Stokes pulses with 1 mJ energy.     

Characterization of Aptamer-Protein Complexes by X-ray Crystallography and Alternative Approaches

Aptamers are oligonucleotide ligands, either RNA or ssDNA, selected for high-affinity binding to molecular targets, such as small organic molecules, proteins or whole microorganisms. While reports of new aptamers are numerous, characterization of their specific interaction is often restricted to the affinity of binding (K(D)). Over the years, crystal structures of aptamer-protein complexes have only scarcely become available. Here we describe some relevant technical issues about the process of crystallizing aptamer-protein complexes and highlight some biochemical details on the molecular basis of selected aptamer-protein interactions. In addition, alternative experimental and computational approaches are discussed to study aptamer-protein interactions.     

Effects on microwave measurements and simulations when collecting data close to edges of wooden boards

Parameters like strength, moisture content, density and grain direction are important when sorting wood according to their individual properties. All those parameters can be correlated to microwave measurements of phase shift and attenuation. Measurements of phase shift and attenuation are, however, affected by the vicinity of a board edge. In this article a simulation of the measurement system is used to create a compensation function for the measurements taken close to edges as if those were taken where no effects of the board edge could be noticed. It is shown, by comparison with real measurements, that by doing this the deviation between the values measured close to the board edges and those measured in the middle of the board is decreased, meaning a higher accuracy can be achieved by using the compensating function.