Growth Rate and Morphology of a Single Calcium Carbonate Crystal on Polysulfone Film Measured with Time Lapse Raman Micro Spectroscopy

The abovementioned physico-chemical factors play an important role in crystal growth on a surface and hence in the performance over time of membrane materials. An understanding of the kinetics governing formation and growth of calcium carbonate crystals on surface is important to gain the ability to predict, control and direct or stop this process.

Many studies have been performed of calcium carbonate crystal growth on a macroscopic scale using indirect methods that monitor changes of solution chemistry. These studies have revealed a dependence of growth kinetics upon parameters such as pH, supersaturation ratio, ionic strength or temperature. Atomic Force Microscopy (AFM) has been extensively used to study mechanisms and growth rates of single crystals from solution, including calcite crystals. The high resolution of AFM can visualize monomolecular steps on atomically flat crystal surfaces. It has been also observed that the AFM tip can influence the growth rate under supersaturated conditions.

 Vertical scanning interferometry is an alternative approach to study growth rates and morphology of single barite crystals. In these approaches the mineralization was studied after seeding. Therefore a measured growth rate is dependent on e.g., seed preparation method. In another study, cryo-electron tomography was used to investigate self-nucleated, template controlled growth of CaCO3 crystals from the solution–phase. Early crystallization events of a few nanometer were observed.

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Characterization of Royal Jelly by Electrospray Ionization Mass Spectrometry Fingerprinting

You are what you eat; and honeybees seem to know this principle well, hence to make a queen bee they feed larvae with royal jelly (RJ). Since the queen bee is fertile, larger and lives longer than most (Apis mellifera) honeybees, this has led humans to consume RJ in traditional medicine and as a health food. The beneficial effect of RJ on human health is still under debate and investigation.

RJ has a complex composition and recent studies have identified lists of volatile and polar components ; but it is generally accepted that RJ is composed of approximately 60% water, proteins (42-41% of dry matter), carbohydrates (30% of dry matter), lipids (8-19% of dry matter) and small amounts of minerals, polyphenols and vitamins. Lyophilized RJ is considered to have less than 5% water and to preserve the same proportions of proteins, lipids and carbohydrates in terms of dry mass.

Since RJ is obtained in much smaller amounts, as compared to most apicultural products, and reaches a high market price, it has been a major target for adulteration. In an evaluation of the physicochemical properties of RJ by different methods, the addition of substantial amounts of yoghurt, egg white, and/or corn starch was detected. The possibility of contamination of RJ with toxic compounds, such as melamine, has also been explored.

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Inhibitory Study for Joint Reactions of Hydrodesulfurization and Hydrodenitrogenation during Hydrotreating of Vacuum Gas Oil

HDS of petroleum fractions is one of the most important processes in the petroleum industry to produce clean fuels. In particular, sulfur removal in diesel fuels is now strongly desirable for environmental and technical reasons. For instance, HDS is used to prevent atmospheric pollution by sulfur oxides produced during the combustion of petroleum-based fuels, to prevent poisoning of sulfur-sensitive metal catalysts used in subsequent reforming reactions and in the catalytic converter for exhaust emission treatment.

Finally, to avoid corrosion problems in engines. The basic nature of these compounds causes them to adsorb onto Lewis acid sites on the catalyst surface, inhibiting the availability of the sites. This poisoning may be reversible or irreversible, depending on the HDS conditions.

 High concentrations of organic nitrogen compounds can cause significant deactivation for reforming, cracking, hydro treating, or any other type of hydro processing catalysts. The present work aims to study the inhibition effect of nitrogen compounds for HDS of DBT in VGO at using carbazole and acridine as non basic and basic compounds respectively over and prepared catalyst (PtMo/alumina) by finding inhibition factor and adsorption constant for each compound in a trickle bed reactor.

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Microemulsification-Based Method: Coupling with Separation Technique

Point-of-use devices represent currently a key field in quantitative analytical sciences. These platforms are low-cost, fast, portable, and simple to use eliminating the necessity for qualified operators. Rapid tests enable in-situ measurements presenting substantial social and economic implications at industry, environment, and medicine. One potential output to perform point-of-use analyses is the accomplishment of the tests in solution with naked eye detection using disposable systems. It allows the determination of different analytes from the use of modified nanomaterial.

Naked eye methods bypasses the use of instrumental readers, an essential feature for in-situ technologies. Furthermore, the analyses in solution surpass precisionrelated downsides when making the tests on substrates such as paper. In this case, the diverse paper substrates that are employed to fabricate the devices affect the flow rates and interactions with analytes.

This paper reports further investigations and application of the microemulsification-based method (MEC), a point-of-use platform that was recently proposed by these authors. It relies on solutionbased- detection with naked eyes. In contrast with colorimetric tools, MEC response depends on colloid thermodynamics by relying on effect of analyte on the entropy of emulsions or Winsor systems. It changes the formation of thermodynamically stable dispersions, the microemulsions. The minimum volume fraction of amphiphile needed to get MEs for a fixed water-oil ratio expressed the analytical signal of the method. The generation of nanodroplets in MEs  allows the naked eye detection of ΦME by monitoring the change of turbidity from the emulsions or Winsor systems. 

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Agriculture and Food Applications of Rhamnolipids and its Production by Pseudomonas Aeruginosa

Microorganisms showed a high capacity of synthesizing a wide range of surface-active compounds, generally called biosurfactants. These compounds are mainly classified according to their molecular weight, physico-chemical properties and mode of action.Many surfactants including rhamnolipids alter the surface properties of liquids, even when present in small quantities. Like other surfactants, rhamnolipids present a lyophilic group and a lyophobic group which facilitate the orientation of the surfactant to reduce the liquid surface free energy and increase surface viscosity.

Some chemical surfactants decontaminated and maintain membrane performance as well as membrane integrity under mild operation conditions. Undefined cleaning activity together with its low biodegradability and high cost most possibly determine the much less frequent use of chemical surfactants in the industrial applications.

Rhamnolipids are potent natural glycolipid biosurfactants often biosynthesized by Pseudomonas aeruginosa strains through the fermentation process, with cheaper agro-based substrates and waste materials. They can be good substituents for chemical surfactants, in different industrial fields. Rhamnolipids are classified as mono-rhamnolipids and di-rhamnolipids, depending on one or two rhamnose sugars linked to a dimer of β-hydroxyacids (primarily β-hydroxydecanoate) which can rise up to three hydroxyl fatty acids containing 8– 14 carbons.

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The Study of Effective of Added Aluminum Oxide Nano Particles to the Drilling Fluid: The Evaluation of Two Synthesis Methods

The rheology is defined as the science of deformation and flow of matter. As a theoretical subject, the rheology is a branch of physics and physical chemistry; commonly classified as a branch of fluid mechanics. The rheology itself has been acknowledged as a separate scientific branch since the mid 1920’s. All real materials will deform to some extent when subjected to stress. If the material is an ideal liquid it may” deform continuously” or flow when a force is applied.

For ideal solids the deformation will be elastic. The relationship between the applied force and the resulting deformation is a unique function of each specific material. For fluids, i.e., liquids and gases, this function is known as a rheological property of the material. Fluids are classified by their rheological behavior American Petroleum Institute. All fluids are classified as either Newtonian or Non-Newtonian, the clearest distinction between different types of fluids.

Flow in circular pipes can behave in different ways. Most common fluids are transported in circular pipes.This is because pipes can withstand a large difference in pressure between the inside and outside of the pipe, without being significantly distorted. The theory behind fluid flow is commonly well understood, yet only fully developed laminar flow is theoretically obtained. Therefore flow with other characteristics, like turbulent flow, must rely on experimental and empirical relations. The borderlines between laminar, transitional and turbulent flow regimes are set by the Reynolds number of the flow.

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Features of N-Glycosylation of Immunoglobulins from Knockout Pig Models

For the first time, the N-glycosylation patterns of immunoglobulin G (IgGs) isolated from the serum of two varieties of knockout pigs (lacking N-glycolylneuraminic acid (Neu5Gc) and/or α 1,3 galactose) were examined for the presence of potential glycan xenoantigens and compared to N-glycosylation patterns obtained for wild-type (WT) pig IgGs.

Glycopeptide analysis was chosen over glycan release, as protein-A eluates from pig serum may contain IgA and IgM as shown previously. The experiments focused on the analysis of tryptic glycopeptides EEQFNSTYR and AEQFNSTYR from IgGs, and excluded IgA and IgM, in which N-glycosylated peptides have different sequences and masses. WT pig IgG glycopeptides showed the presence of N-glycolylneuraminic acid (Neu5Gc) and absence of N-acetylneuraminic acid (Neu5Ac). Released glycans from the protein-A eluate, however, showed the presence of both types of sialic acids, allowing Neu5Ac to be attributed to IgA and/or IgM.

The WT IgG samples also showed the presence of glycans that could by composition have been α-galactosylated, but treatments with α- and β-galactosidases produced inconclusive results as to the linkage nature of the terminal Gal residues. Single knockout (α-Gal transferase) pig IgG was shown to contain Neu5Gc residues, and there was a definite absence of α-Gal.