Scale Inhibition of Green Inhibitor Polyepoxysuccinic Sodium

Polyepoxysuccinic acid (PESA) is the green water treatment agents recognized all over the world[1-3]. It is found that when PESA is used alone, it had good scale inhibition. PESA should be included in the category of green scale inhibitor. PESA is synthesized with maleicanhydride in the presence of catalysts. The effect on scale-in-hibiting property of the product from amount and feed times of catalyst, the reaction temperature, the reaction time were investigated. The optimum reaction c…     

Novel and Gram‐Scale Green Synthesis of Flutamide

Isobutyric acid in the presence of cyanuric chloride and N‐methylmorpholine was converted into active ester 3 at 0–5 °C, and it was subsequently treated with 3‐aminobenzotrifluoride 4 at 25 °C to furnish corresponding amide 5. This amide finally, on nitration, produced the desired product flutamide, 2‐methyl‐N‐[4‐nitro‐3‐(trifluoromethyl)phenyl]propionamide 6 in good yield. By‐product 2,4,6‐trihydroxy‐1,3,5‐triazine 7 was converted into the useful starting material cyanuric chloride 1 by refluxing with N,N‐diethylamine and POCl₃.     

Convenient Large‐Scale Synthesis of Universal Solid Support

A simple, convenient large‐scale synthesis of a universal solid support useful for the synthesis of oligonucleotides is described.     

Lattice Compression Revealed at the ≈1 nm Scale

Lattice tuning at the ≈1 nm scale is fascinating and challenging; for instance, lattice compression at such a minuscule scale has not been observed. The lattice compression might also bring about some unusual properties, which waits to be verified. Through ligand induction, we herein achieve the lattice compression in a ≈1 nm gold nanocluster for the first time, as detected by the single-crystal X-ray crystallography. In a freshly synthesized Au₅₂(CHT)₂₈ (CHT=S-c−C₆H₁₁) nanocluster, the lattice distance of the (110) facet is found to be compressed from 4.51 to 3.58 Å at the near end. However, the lattice distances of the (111) and (100) facets show no change in different positions. The lattice-compressed nanocluster exhibits superior electrocatalytic activity for the CO₂ reduction reaction (CO₂RR) compared to that exhibited by the same-sized Au₅₂(TBBT)₃₂ (TBBT=4-tert-butyl-benzenethiolate) nanocluster and larger Au nanocrystals without lattice variation, indicating that lattice tuning is an efficient method for tailoring the properties of metal nanoclusters. Further theoretical calculations explain the high CO₂RR performance of the lattice-compressed Au₅₂(CHT)₂₈ and provide a correlation between its structure and catalytic activity.     

Corrosion Inhibition of a Green Scale Inhibitor Polyepoxysuccinic Acid

The corrosion inhibition of a green scale inhibitor, polyepoxysuccinic acid (PESA) was studied based on dynamic tests. It is found that when PESA is used alone, it had good corrosion inhibition. So, PESA should be included in the category of corrosion inhibitors. It is not only a kind of green scale inhibitor, but also a green corrosion inhibitor. The synergistic effect betweenPESA and Zn2 or sodium gluconate is poor. However, the synergistic effect among PESA, Zn2 and sodium gluconate is excellent, and the corrosion inhibition efficiency for carbon steel is higher than 99%. Further study of corrosion inhibition mechanism reveals that corrosion inhibition of PESA is not affected by carboxyl group, but by the oxygen atom inserted. The existence of oxygen atom in PESA molecular structure makes it easy to form stable chelate with pentacyclic     

Jahn–Teller Disproportionation Induced Exfoliation of Unit-Cell Scale ϵ-MnO2

Exfoliation of non-layered (structurally) bulk materials at the nanoscale is challenging because of the strong chemical bonds in the lattice, as opposed to the weak van der Waals (vdW) interactions in layered materials. We propose a top-down method to exfoliate ϵ-MnO₂ nanosheets in a family of charge-ordered La_1−xAE_xMnO₃ (AE=Ca, Sr, Ba) perovskites, taking advantage of the Jahn–Teller disproportionation effect of Mn³⁺ and bond-strength differences. ϵ-MnO₂ crystallized into a nickel arsenide (NiAs) structure, with a thickness of 0.91 nm, displays thermal metastability and superior water oxidation activity compared to other manganese oxides. The exfoliation mechanism involves a synergistic proton-induced Mn³⁺ disproportionation and structural reconstruction. The synthetic method could also be potentially extended to the exfoliation of other two-dimensional nanosheet materials with non-layered structures.     

Preparation of GaN Powder of Nanometer Scale by MOCVD Using DEGA as Precursor

IUtroductfonGalliumnitride(GaN)isanimportantandattractive,-Vserniconductror-IthassomespeialproPerties,suchasdirectwidebandgap(3-45eV),highelectricalandthermalconductivitiesandhighdecompositiontemperature(>l0OOC),whichmakeitusefulinfabricationofelectricandoptoelectronicdevices[lj-Theknownsyntheticproceduresfor0btainingbulkPOwderofGaNinvolvethereactionofvariousgalliumsources,suchasGa,0,,GaorLNH.j,LGaF,jwithammonia,conductedathightemperature(900C).Recently,somenovelorganogalliumprecursor…     

Growth of Aligned Carbon Nanotubes on Large Scale by Methane Decomposition with Deactivation Inhibitor

The effects of additives containing iron or nickel during chemical vapor deposition(CVD)on the growth of carbon nanotubes(CNTs)by methane decomposition on Mo/MgO catalyst were investigated. Ferrocene and nickel nitrate were introduced as deactivation inhibitors by in-situ evaporation during CVD. The precisely controlled in-situ introduction of these inhibitors increased the surface renewal of catalyst, and therefore prevented the catalyst from deactivation.Using this method,aligned multi-walled CNTs with parallel mesopores can be produced on a large scale.     

Bacterial Reduction of Cr(VI) at Technical Scale—The Malaysian Experience

The bacterial reduction of Cr(VI) from industrial wastewater was evaluated using a 2.0-m³ bioreactor. Liquid pineapple waste was used as a nutrient for the biofilm community formed inside the bioreactor. The use of rubber wood sawdust as packing material was able to immobilize more than 10⁶?CFU?mL^?1 of Acinetobacter haemolyticus cells after 3?days of contact time. Complete reduction of 15?C240?mg?L^?1 of Cr(VI) was achieved even after 3?months of bioreactor operation. Cr(VI) was not detected in the final effluent fraction indicating complete removal of Cr from solution from the flocculation/coagulation step and the unlikely re-oxidation of Cr(III) into Cr(VI). Impatiens balsamina L. and Gomphrena globosa L. showed better growth in the presence of soil?Csludge mixture compared to Coleus scutellarioides (L.) Benth. Significant amounts of Cr accumulated at different sections of the plants indicate its potential application in Cr phytoremediation effort. The bacterial-based system was also determined not to be detrimental to human health based on the low levels of Cr detected in the hair and nail samples of the plant operators. Thus, it can be said that bacterial-based Cr(VI) treatment system is a feasible alternative to the conventional system especially for lower Cr(VI) concentrations, where sludge generated can be used as growth supplement for ornamental plant as well as not detrimental to the health of the workers.     

Influence of Mg^2＋ on Initial Stages of CaCO3 Scale Formed on Metal Surface

Magnesium ions, which exist in formation water and injection water under downhole conditions in the oil and gas production industry, are a key determinant in the CaCO3 scale formation. Many studies have focused their attention on the effect of magnesium on the kinetics, the morphology and the content of Mg in the Ca-CO3 scale. Little attention has been paid to the effect of Mg^2 on the initial stages of CaCO3 formation on a metal surface. In this study, an electrochemical technique was used to study the influence of Mg^2 on the ini-tial stages of CaCO3 scale formed on a metal surface. With this electrochemical technique, the reduction of the dissolved oxygen in an analysis solution is considered on the surface of a rotating disk electrode (RDE) un-der potentiostatic control. The rate of oxygen reduction on the surface of the RDE enables the extent of sur-face coverage of scale to be assessed. With this electrochemical technique, a new insight into the effect of Mg^2 on CaCO3 scale formed on a metal surface is given.     

Collision Induced Dissociation of Benzylpyridinium-Substituted Porphyrins: Towards a Thermometer Scale for Multiply Charged Ions?

We have determined breakdown curves for a range of multiply charged benzylpyridinium-substituted porphyrin cations by collision induced dissociation measurements (CID) as mediated by resonant pulsed radio-frequency (rf) excitation in a helium-filled linear ion trap. Measurements were compared with the predictions of DFT calculations. We find a linear correlation between experimental fragmentation thresholds (in instrumental units of “normalized collision energy”) and theoretical dissociation energies, suggesting that these species can be used as calibrants to gauge the fragmentation energetics of closely related systems. We have confirmed this by also studying the fragmentation thresholds of metalloporphyrin-based ions – including multiply negatively charged metalloporphyrin oligomers. Unfortunately, the slope of the linear correlation obtained for benzylpyridinium-substituted porphyrin multications differs significantly from that obtained by us for a set of smaller, singly charged substituted benzylpyridines put forward as “thermometer” ions in previous work. Multiplying the threshold energies in an ad hoc fashion by the ion charge basically reconciles both calibration curves. We conclude that one should use caution when applying small, singly charged benzylpyridines as calibrants to gauge the CID of large, multiply charged ions in ion-trap mass spectrometers.

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Graphical Abstract

     

Synthesis of MA/AA/MA-β-CD/SHP Quadripolymer and Its Performance Evaluation as Scale Inhibitor

A new scale inhibitor MA/AA/MA-β-CD/SHP was prepared from maleic anhydride, acrylic acid, sodium hypophosphite, and MA-β-CD via the method of free radical polymerization in aqueous solution. The MA-β-CD was obtained through the modification of β-cyclodextrin (β-CD) with maleic anhydride (MA). Results of performance evaluation showed that the synthesized copolymer has excellent scale inhibition effect for the calcium scale, and the resistance rate of silicon scale up to 79.81%. The structure, thermal property, and morphology of the copolymer were characterized by FTIR, TGA, and SEM. From crystallization data and morphology of the scale crystals it was found that the copolymer scale inhibitor can make the crystal lattice distortion, and has a good dispersing ability after addition of the scale inhibitor.     

A History of Fischer-Tropsch Wax Upgrading at BP—— from Catalyst Screening Studies to Full Scale Demonstration in Alaska

Conversion of Fischer-Tropsch wax into high quality synthetic crude or finished transportation fuels such as premium diesel has been studied over the past 15 years within BP. Catalyst screening and selection was carried out in dedicated micro-reactors and pilot plants, whose designs are critical to the performance selection. Variation in catalyst composition and defining the gas to oil feed ratios with the operating temperature are a few of the parameters studied. Product selection and maximizing diesel yield combined with stability (catalyst life) were the ultimate drivers. The selected catalyst was then tested under commercial conditions in a dedicated 300 barrel per day demonstration plant. The products were also tested in engines to assess their combustion characteristics.     

Large Scale Purification of Immunregulatory Peptide Nα 1, N∊2- Diacetyl-Splenopentin by Chromatography on a Carboxylated Cation Exchanger

Abstract

The immunregulatory pentapeptide ARG-LYS-GLU-VAL-TYR was synthesized by using the mixed anhydride coupling method. Acylation of N^α1- and N^?2-amino groups increases the enzymatic degradation stability of splenopentin. This paper describes a simple and effective large scale purification method of N^α1-, N^?2-diacetyl-splenopentin synthesis product by chromatography on the carboxylated cation exchanger Wofatit Y 79. Using ethanol/acidic water as eluent the isolation of purified peptide from the eluat was achieved directly by evaporation under vacuum and lyophilisation.     

The Utilization of Gum Tragacanth to Improve the Growth of Rhodotorula aurantiaca and the Production of γ-Decalactone in Large Scale

The production of γ-decalactone and 4-hydroxydecanoic acid by the psychrophilic yeast R. aurantiaca was studied. The effect of both compounds on the growth of R. aurantiaca was also investigated and our results show that γ-decalactone must be one of the limiting factors for its production. The addition of gum tragacanth to the medium at concentrations of 3 and 4 g/l seems to be an adequate strategy to enhance γ-decalactone production and to reduce its toxicity towards the cell. The production of γ-decalactone and 4-hydroxydecanoic acid was significantly higher in 20-l bioreactor than in 100-l bioreactor. By using 20 g/l of castor oil, 6.5 and 4.5 g/l of γ-decalactone were extracted after acidification at pH 2.0 and distillation at 100 °C for 45 min in 20- and 100-l bioreactors, respectively. We propose a process at industrial scale using a psychrophilic yeast to produce naturally γ-decalactone from castor oil which acts also as a detoxifying agent; moreover the process was improved by adding a natural gum.     

Studies on the Renaturation with Simultaneous Purification of Recombinant Human Proinsulin with Unit of Simultaneous Renaturation and Purification of Protein in Semi－preparative Scale

The recombinant human proinsulin (rh-proinsulin) is the precursor of insulin, which is connected with C- peptide between the carboxyl-terminal of chain A and NH2-terminal of chain B of insulin. In the presences of trypsin and carboxypeptides B (CPB), the C-peptide can be cleaved from the special two peptides of rh-proinsulin and the recombinant human insulin (rh-insulin) can be, thus, obtained1,2. The rh-proinsulin expressed in E. coli exists as inclusion body, hardly dissolves in water,…     

Calibration of the X‐Ray Photoelectron Spectroscopy Binding Energy Scale for the Characterization of Heterogeneous Catalysts: Is Everything Really under Control?

Investigations of X‐ray photoelectron spectra from solid samples need corrections for the surface charging effect. For powder samples such as heterogeneous catalysts and their supports, the C ? (C,H) component of the C 1s peak is often used as an internal standard for the calibration of the binding energy scale. Although this method is widely recognized as suitable for the study of heterogeneous catalysts, we show that a significant calibration bias can be encountered upon comparing samples with different bulk composition. In this paper, a series of SiO₂–Al₂O₃ supports and Pd/SiO₂–Al₂O₃ catalysts with various Si/Al ratios were studied. The spectra issued from these samples were processed with the classical calibration method on the basis of the carbon peak. Important discrepancies in the relative position of the photoelectron peaks were noticed. After systematically discarding instrument‐related issues, a true chemical influence of the bulk matrix on the analyzed surface species was evidenced. The extent of this chemical effect was dependent on the composition of the sample and more precisely on its ionicity. Two possible mechanisms for this chemical effect were proposed and discussed. Finally, an alternative calibration method was offered.