Miracle-dz/UniFAR-FTUs huggingface dataset:
The chemistry and analysis of annatto food colouring: a review

Annatto food colouring (E160b) has a long history of use in the food industry for the colouring of a wide range of food commodities. The principal colouring component of annatto is the oil-soluble diapo carotenoid bixin, which is the methyl ester of the dicarboxylic acid norbixin and soluble in aqueous alkali. Bixin and norbixin, therefore, exhibit not only physicochemical properties normally associated with carotenoids, but also certain anomalous properties that have an impact on the stability, food colouring applications, and importantly the analysis of annatto. This review summarizes the key aspects of the structural determination of bixin (and norbixin) with special attention to cis-trans isomerization and how this links with its chemical structure, spectroscopic properties, and stability. The oxidative, thermal, and photo-stability of annatto and the subsequent implications for its use in the colouring of foods, food processing, and the analysis of foods and beverages are discussed along with important mechanistic, thermodynamic and kinetic aspects. The main analytical techniques used for the chemical characterization of annatto, i.e. spectrophotometry, nuclear magnetic resonance (NMR), chromatography (particularly high-performance liquid chromatography (HPLC)) and mass spectrometry are reviewed in detail and other methods are discussed. This links in with a review of the methods available for the detection and measurement of annatto in colour formulations and foods and beverages, which highlights the importance of the need for a good understanding and knowledge of the chemistry of bixin and norbixin in order to meet new analytical challenges.
Growth of ionization currents in nitrogen

Townsend's primary and secondary ionization coefficients α/p and γ were determined in nitrogen over a wide range of E/p (100-1000 V cm−1 Torr−1) and p (0·4 to 12 Torr at 0 °C) using the pressure variation technique. This technique, along with the Gosseries method of evaluation of ionization coefficients, seems to be more suitable at higher values of E/p, since the errors in these coefficients could be minimized by a suitable selection of p and d, thus eliminating the non-equilibrium ionization condition.
The production of prop-2-ynylideneamine by thermolysis of N-chloropropargylamine, N-fluoropropargylamine and N-hydroxypropargylamine: a computational study

Ab initio molecular orbital calculations using MP2 and DFT/B3LYP methods at the 6-311++G(d,p) and aug-cc-pvdz basis sets were applied to characterise the kinetics of the thermal dissociation of HC≡CCH2NHX [where X = OH(I), F(II) and Cl(III)] to produce Z- and E-prop-2-ynylideneamines (HC≡CCH=NH) (IV and V, respectively), which tautomerise to vinyl cyanide (CH2=CHC≡N) (VI). The optimised geometries and electronic energies of reactants, transition states and products were estimated and discussed. A concerted proton migration and HX abstraction mechanism was proposed for the imine formation. The reliance of these properties on the elected levels of theory was discussed. The activation energies and barrier heights for the Z- and E-forms and their vinyl cyanide tautomers were estimated and analysed. The Z-form was computed to be more stable than the E-form. Using natural bond orbital calculations, the origin of the preference of the Z-form was attributed mainly to the N lone pair delocalisations. Vinyl cyanide was located to have a lower energy (33–35 kcal/mol) than prop-2-ynylideneamine. The provenance of the preference of the former and its tautomerisation mechanism will be addressed in a separate publication.
Sequential extraction analysis of metals in sediments from the Hara Biosphere Reserve of Southern Iran

Abstract The concentration and chemical speciation of Pb, Cd and Ni as well as the total organic carbon (TOC) were studied in surface sediments from nine stations in the Hara Biosphere Reserve. The sequential extraction technique was applied to assess the four (exchangeable, acid-reduction, oxidisable-organic and residual) fractions in surface sediment. This investigation was the first study on the basis of the chemical speciation of Pb, Cd and Ni in surface sediments of Hara Biosphere Reserve. The total concentrations of metals were 31.66–42 μg g-1 for Pb, 3.08–4 μg g-1 for Cd and 36.81–118.9 μg g-1 for Ni. The highest percentages of Pb, Cd and Ni were found in the resistant fractions; 51.42%, 60.11%, 91.71%, respectively, indicating that these metals were strongly bound to the sediments. The degree of surface sediments contamination was determined for the individual contamination factors (ICF). The result of ICF values illustrated that all stations (with the exception of stations 3 and 8 for Pb) did not pose a potential risk to fauna and flora of the Hara Biosphere Reserve. The Pearson correlation between the concentration of Pb, Cd, and Ni at the oxidisable-organic fraction with TOC in surface sediment demonstrated that TOC had a positive effect on complexing with metals in the surface sediment. The wastewater from industry was the main source of metal pollution in this region.
Nω‐Nitro‐L‐arginine Administration Corrects Peripheral Vasodilation and Systemic Capillary Hypotension and Ameliorates Plasma Volume Expansion and Sodium Retention in Portal Hypertensive Rats

In portal hypertensive states, peripheral vasodilation leads to sodium retention and plasma volume expansion. Nω‐nitro‐L‐arginine, a specific biosynthesis inhibitor of the vasodilator nitric oxide, has been shown to acutely reverse peripheral vasodilation and the vascular hyporesponsiveness to endogenous and exogenous vasoconstrictors observed in portal hypertensive rats. This study investigated whether Nω‐nitro‐L‐arginine treatment in portal hypertensive rats prevents peripheral vasodilation and therefore ameliorates plasma volume expansion and sodium retention. For 2 days before partial portal vein ligation or sham operation and then continuously for 4 days after the operation, animals received either placebo (0.9% saline) or Nω‐nitro‐L‐arginine (˜2 μg/kg/min) intravenously through a subcutaneously implanted Alzet osmotic pump (model 2ML1; Alza, Palo Alto, CA). In portal hypertensive rats, Nω‐nitro‐L‐arginine treatment significantly increased mean arterial pressure (placebo vs. Nω‐nitro‐L‐arginine, 123 ± 4 vs. 150 ± 2 mm Hg, respectively; p < 0.001) and systemic vascular resistance (3.8 ± 0.2 vs. 5.6 ± 0.3 mm Hg/ml/min/100 gm body weight; p < 0.001), associated with a decrease in the cardiac index (33.5 ± 1.0 vs. 27.0 ± 1.1 ml/min/100 gm body weight; p < 0.001). Nω‐nitro‐L‐arginine treatment also induced a decrease in plasma volume (4.6 ± 0.1 vs. 4.1 ± 0.1 ml/100 gm body weight; p < 0.001) and extracellular sodium space (39.4 ± 0.7 vs. 37.4 ± 0.4 ml/100 gm body weight; p < 0.05) without changes in serum sodium. In addition, Nω‐nitro‐L‐arginine corrected the decreased capillary pressure observed in portal hypertensive rats. Capillary pressure negatively correlated with plasma volume but not with sodium space. In contrast, Nω‐nitro‐L‐arginine infusions in sham‐operated rats significantly elevated mean arterial pressure without modifying plasma volume and sodium space. These results demonstrate that correction of peripheral vasodilation and capillary hypotension by Nω‐nitro‐Larginine ameliorates plasma volume expansion and sodium retention in portal hypertensive rats. (HEPATOLOGY 1993;17:84–90.)
Phase‐object approximation in small‐angle neutron scattering experiments on silicon gratings

The phase-object approximation for neutron scattering based on a one-dimensional dynamic forward scattering theory is discussed and used to calculate the differential cross section of an object. It is shown that this approximation is valid in ultra-small-angle neutron scattering (USANS) and spin-echo small-angle neutron scattering (SESANS) experiments on silicon gratings. In the weak scattering limit, the phase-object approximation reduces to the kinematic or first Born approximation. The spatial coherence function is used to describe instrumental resolution effects. Measurements on three different instruments are in good agreement with calculation results. In the experiment with a time-of-flight SESANS instrument, the effect of Pendellosung with object size is observed.
MULTICOMPONENT KINETIC ANALYSIS OF IRON SPECIATION IN HUMIC LAKE TJEUKEMEER : COMPARISON OF FULVIC ACID FROM THE DRAINAGE BASIN AND LAKE WATER SAMPLES

Iron speciation in Lake Tjeukemeer, The Netherlands, was studied by multicomponent kinetic analysis of the ligand-exchange reactions between 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ) and naturally occurring ligands bound to iron. Comparison with the kinetic behavior of iron in synthetic solutions made of extracted fulvic acids from the Lake drainage basin indicates that iron is distributed in two forms: polymeric hydrous oxides and, possibly, iron fulvates
Hydrothermal Synthesis of Alpha Alumina (α‐Al2O3) Powders: Study of the Processing Variables and Growth Mechanisms

Alpha alumina (α-Al2O3) powders and α-Al2O3/boehmite (γ-AlOOH) mixtures with controlled γ-AlOOH contents were synthesized hydrothermally under alkaline or acidic conditions at 380°–435°C for 1–10 days, under 6.9–14.5 MPa pressure, from concentrated precursors without stirring. The precursors were formed by mixing different types of aluminum hydroxides with water, and optionally with α-Al2O3 seeds, hydrogen peroxide, sulfuric acid, dopants (i.e., KMnO4), and/or other additives. The experiments were performed on industrial scale in large production autoclaves. The synthesized α-Al2O3 powders exhibited up to 100% phase purity, 99.98% chemical purity, equiaxed morphology, low aggregation levels, narrow crystallite size distributions with primary particle sizes ranging between 100 nm and 40 μm, and high reproducibility. Precursor types, seeds, chemical additives, and temperature/time of the hydrothermal synthesis were found to govern properties of the powders. Different growth mechanisms for nanosized and rough powders are discussed. Results of this study enable the use of hydrothermal α-Al2O3 powders in a multitude of applications, and make their hydrothermal production a commercial reality.
Similitude modeling and experiments on a moving bed granular filter

The purpose of this research is to improve the performance of moving bed granular filters. Granular bed filters are one type of filter that shows good promise for hot-gas clean-up in advanced coal conversion technologies. This research project examines the performance of a moving bed granular filter under conditions simulating hydrodynamic flow at high temperature, high pressure typical of advanced coal-fired power systems. The tests were carried out in a cold-flow model of a moving bed granular filter. Inlet ash concentration, outlet ash concentration, filter collection efficiency and pressure drop across the bed data were experimentally collected. Seven experiments were conducted to investigate the effects of several factors on filter collection efficiency. These factors include 1. Ash deposition rate to granule flow rate ("mass dust ratio") 2. Size of granules used as the filter media 3. Bed pressure 4. Superficial velocity at the filter interface The results of cold model tests provide information important to future tests performed at high pressure and high temperature conditions. The results also give important information for the design of moving bed filters for commercial application.
Surface modification of polycaprolactone substrates using collagen-conjugated poly(methacrylic acid) brushes for the regulation of cell proliferation and endothelialisation

The incorporation and presentation of cell recognition ligands on the surfaces of biodegradable blood-vessel implants to promote endothelialisation is considered to be a promising approach to prevent platelet aggregation and hence thrombogenesis. In this study, cell-adhesive collagen was covalently immobilised onto polycaprolactone (PCL) substrates via surface-initiated atom transfer radical polymerization (ATRP) to improve cell–material interactions. Functional polymer brushes of poly(methacrylic acid) (P(MAA)) containing dense and reactive carboxyl groups (–COOH) were formed on the PCL substrates in a controllable manner. The amount of collagen, which was conjugated to the pendant carboxyl groups via carbodiimide chemistry, increased with the concentration of –COOH groups on the grafted P(MAA) brushes. The affinity and growth of endothelial cells (ECs) were found to be significantly improved on the collagen-immobilised PCL substrates, and this improvement is positively correlated with the amount of covalently conjugated collagen. Thus, surface-initiated ATRP provides an alternative methodology for the surface functionalisation of biodegradable polyester scaffolds to enable the formation of a confluent layer of ECs. An optimally endothelialised material surface will play a major role in the minimisation of thrombogenicity and inflammation, and hence can be potentially used for vascular graft applications.
Concentration dependence of adsorption from human whole resting saliva at solid/liquid interfaces: An ellipsometric study

The rates and plateau values of adsorption at the solid/ liquid interface from human whole resting saliva from three male donors were studied in vitro. The influence of saliva concentration, the total protein content and the wettability of the exposed solids was investigated. Ellipsometry was used to study the rate and plateau values of the adsorption process in situ. The solid surfaces used were hydrophilic, negatively charged, silica and hydrophobic methylated silica. Salivary films were formed by adsorption from solutions of 0.05%, 0.10%, 0.20%, 0.50%, 1.0% and 2.0% (v/v) saliva in phosphate buffered saline. The results revealed that adsorption onto both types of surfaces was a rapid and, as expected, a concentration dependent process. The adsorbed amounts were in the range of monomolecular layers and were found to be larger onto the hydrophobic than the hydrophilic surfaces (p≤0.0062). A strong concentration dependence was denoted in all cases (p< 0.0001). Inter‐individual differences were found not t.
Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes: Effects of Fouling, Modelling and Water Reuse

The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending on the properties of compounds and types of membranes. Thus, quantification of removals is studied by means of multivariate data analysis techniques and more understanding of the separation of micropollutants by membranes is achieved. Water reuse practices will increase due to overpopulation of cities, in that sense water membrane treatment will play an important role for the removal of micropollutants, therefore is important to understand characteristics, advantages and disadvantages of NF and RO, this book helps to achieve that understanding.
Flexible polyurethane foams modified with natural oil based polyols

Polyols based on natural oils can be used in formulations of various polyurethane materials including foams with the cell structure and properties required for their typical applications. Vegetable oils such as rapeseed and palm oils were used as raw materials for preparing flexible polyurethane foams. The reference polyurethane systems were elaborated on the basis of petrochemical polyols. These formulations were modified with rapeseed and palm oil based polyols. The effects of such modifications on selected physical–mechanical properties of prepared foams are discussed. The application of both vegetable oil based polyols allowed to obtain the foams with higher ability for energy absorbing and better thermal stability.
Determination of displacements from nanoprecipitates in a Cu–Ni–Fe single crystal using anomalous small-angle and large-angle X-ray scattering

Single crystals of Cu–41.5 at. % Ni–16 at. % Fe have been studied by small-angle and large-angle X-ray scattering in order to determine the displacements induced by the disc-like precipitates formed during decomposition. The small-angle X-ray scattering (SAXS) patterns gave information on the size and the organization of the precipitates, while the scattering near Bragg peaks allows a determination of the distortions of the lattice created by these precipitates. The variations of the atomic scattering factors of Fe, Ni and Cu (for the large-angle measurements) were used to determine both the partial structure functions (`chemical' data) and the partial displacements. The precipitates were found to be enriched in Fe and Ni, which induced a contraction of the lattice, while the depleted matrix (mainly Cu) was dilated. This succession of compressed and dilated regions is very stable and prevents a single precipitate from growing much in this direction during coarsening. This can explain why a single precipitate tends to grow mainly in the orthogonal directions, where the extension of the displacements is smaller than the precipitated region.
Photopolymerization with microscale resolution: Influence of the physico‐chemical and photonic parameters

This article is aimed at demonstrating that physicochemical parameters can be used to control the spatial extent (length, width, and shape) of polymer objects in view of micro- and nano-fabrication applications. In particular, we showed that oxygen quenching and internal filter effects could be turned to advantage to modulate the response of the material by controlling the threshold energy of polymerization and/or the shape of the light into the photopolymerizable medium. The experimental configuration used in this study is based on light-induced polymerization at the extremity of an optical fiber that produces polymer micro-objects after development. Spectroscopic approaches and polymerization threshold measurements were performed to quantitatively evaluate the influence of the physicochemical parameters on the micropatterning of photopolymerizable material. Interestingly, fluorescence that is usually regarded as a process competing with photopolymerization reaction, was used for controlling the fabrication process. By this means, it was possible to better understand the impact of a nonhomogeneous irradiation on photopolymerization process and thus, to tune the shape and the size of the final polymer objects.
One-step growth of needle and dendritic gold nanostructures on silicon for surface enhanced Raman scattering

Light-induced deposition of gold nanostructures onto both n-type and p-type silicon was performed by galvanic displacement. On illuminating the n-type silicon with a 530 nm laser during the deposition process, a clustered deposit was observed whereas on using a 635 nm laser, gold nano-needles were formed. In comparison, on depositing gold on p-type silicon, flat dendritic structures were obtained and no significant changes in morphology were observed in the presence or absence of light. In the dark, only irregular gold clusters formed. The influence of light in changing the morphology was related to the surface plasmon resonance of the gold nuclei as well as the excess charge present in the conduction band of the silicon. To evaluate the sensoric property of the substrates, Raman spectroscopy was conducted on the metal–semiconductor couple for the detection of ruthenium red molecule. Among the substrates, the gold needle–silicon couple gave the highest surface enhanced Raman scattering (SERS) enhancement. We could also conclude from the SERS measurements that the metal–semiconductor interface plays an important role in increasing the SERS signal.
Dissolution of uranium, neptunium, plutonium and americium oxides in tri-n-butyl phosphate saturated with nitric acid

Uranium dioxide and its solid solutions with neptunium, plutonium and americium dioxides can be efficiently and quantitatively dissolved using tri-n-butyl phosphate (TBP) saturated with nitric acid. Individual NpO2 and PuO2 do not dissolve under these conditions. On the treatment of a mechanical mixture of UO2 with PuO2 and NpO2 with TBP–HNO3, a complex of uramiun completely dissolved, whereas Np and Pu remained in the residue.
The effect of ECF and TCF bleaching on the chemical composition of soda-anthraquinone and kraft pulp surfaces

The surface chemistry of a sulfur free processed (soda-anthraquinone, soda-AQ) softwood pulp (kappa 23.1) was compared to that of a kraft pulp (kappa 21.3) prepared from the same wood. The pulps were bleached using sequences OQDPDP and OQPP. The surface coverage by lignin and extractives was determined by X-ray photoelectron spectroscopy (XPS/ESCA) after each bleaching stage. The results were compared with the coverages on fibers from which the fines and the fiber surface material had been removed. The surface lignin on soda-AQ pulp (i.e. the lignin on the surface of fibers and fines) was seven times more resistant to OQDPDP bleaching than the total pulp lignin. The surface lignin on kraft pulp was five times more resistant than the pulp lignin. The lower reactivity of the surface lignin to a large extent seems to be due to the presence of lignin-carbohydrate linkages and a lower content of phenolic hydroxyls in the surface lignin. Alkaline stages (O or P) removed surface lignin in kraft pulp quite extensively, while the D stage was less effective. In contrast, the surface lignin on soda-AQ pulp was quite resistant to oxygen delignification but was removed effectively in the D stage. The surface coverage by extractives was also affected by the different cooking methods applied. The relative concentration of extractives on the surface of the pulp increased throughout the bleaching process. This effect was more marked on kraft pulp than on soda-AQ-pulp. Surface extractives on both soda-AQ and kraft pulps were more difficult to remove by oxygen than the extractives on the lightly peeled fiber surfaces. Thus, the extractives on the unbleached and oxygen-delignified pulp surfaces are very tightly bound to other compounds on the pulp surface, e.g. via multivalent metal ions. The fully bleached ECF pulp is covered to a larger extent by extractives than by lignin, which is expected to be of importance when the fibers are used in papermaking.
Persistence and fate of anthracene and benzo(a)pyrene in municipal sludge treated soil

Greenhouse studies using pots and microcosms were conducted to investigate the persistence and fate of nonlabeled and {sup 14}C-labeled anthracene (ANT) and benzo(a)Pyrene (B(a)P) in sludge treated soil. Results indicated that ANT degraded rapidly (t{sub {1/2}} {approx} 3 wk) from the experimental systems, but that B(a)P was persistent. Cropping did not affect the persistence of either compound. On completion of the experiments {le} 10% of the ANT added to soil was recovered intact, whereas 78% of the B(a)P added to soil was recovered intact. Most ({ge}85%) of the {sup 14}C added to soil as labeled ANT and B(a)P was accounted for. Recoveries of {sup 14}CO{sub 2} indicated significant mineralization of ANT, but not of B(a)P. Trivial amounts ({le}0.2%) of {sup 14}C were recovered as volatile organics and in plant materials, but large amounts were recovered from soil. A considerable proportion of the ANT derived {sup 14}C in soil was not extracted with acetone/hexane, which indicated that it had been converted to bound residue. a much smaller proportion of B(a)P than of ANT derived {sup 14}C in soil was converted to bound residue. No evidence was obtained for uptake of intact ANT or B(a)P by ryegrass (lolium multiflorum Lam.), soybean [Glycinemaxmore » (L.) Merr. ], and cabbage (Brassica oleracea var. capitata L.). 25 refs., 3 figs., 6 tabs. « less