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Using the DPPH method, the antioxidant properties of six flavonoids with various basic chemical structures from the three species of Artocarpus (A. nangkadak, A. champeden, and A. altilis) were investigated. In addition, the flavonoids Cudraflavone C (flavone), artocarpin (flavone), and artocapanon (flavane), which have distinct basic structures but the same hydroxylation pattern (2' and 4'-OH in the B-ring, respectively), were given special consideration. Since all three flavonoids showed comparable antioxidant activity against DPPH, it can be said that the presence of the 7-OH group, the 2' and 4'-OH groups in the B ring, and the 2,3-double bond is a sign of strong antioxidant potency. Moreover, prenyl groups and structural modification involving these groups to flavonoids, such as cyclization of the 3-prenyl to make a pyranohydrobenzoxanthone type (cycloartocarpine, cyclomorusin, cyclocommunol) can decrease antioxidant activities. [ABSTRACT FROM AUTHOR]

The investigation of Fe2+-dependent reaction on methyl orange (MO) biodegradation by brown-rot fungus Daedalea dickinsii was performed to evaluate the involvement of Fenton reaction. The MO degradation (final concentration 75 mg/L) was evaluated for incubation period at 0, 7, 14, 21, and 28 days in mineral salt media with and without Fe2+. UV-Vis Spectrophotometer and LC-TOF/MS were used for degradation analysis. The highest MO decolorization by D. dickinsii was approximately 77.1% and 60.5% in medium without and with Fe2+, respectively, occurred for 28 days incubation. It indicated that the optimum decolorization was obtained in medium without Fe2+, which assumed that Fe2+ dependent reaction might be not enhanced decolorization of MO by D. dickinsii. Based on LC-TOF/MS analysis, 2-hydroxy-4((2-hydroxy-4(methylamino) phenyl) diazinyl) phenolate (C13H12N3O3), and 4-(2-(4-(dimethylamino)-2,3,5,6-tetramethoxy phenyl) hydrazinyl)-2,3,5,6-tetramethoxy benzenesulphonate (C22H32N3O11S) were detected as metabolites of MO degradation. C13H12N3O3 was a transformation product of demethylation, hydroxylation and desulfonation, while C22H32N3O11S was a product of methoxylation. This study indicated that the methyl orange (MO) decolorization was a hybrid process between Fenton's mechanism and enzymatic activity. [ABSTRACT FROM AUTHOR]

The preparation of polyurethane (PU) foam using green-based polyol from soybean oil as an alternative for petroleum-based polyurethane. The polyurethane was fabricated by using the prepolymer method following the two steps namely epoxidation and alcoholysis reaction. The FTIR, hydroxyl numbers were used to monitor the process of the synthesized polyol and determined the physicochemical properties. Choosing a suitable method for the processing of polyurethane foam soy-based became a major to the success of the production. Temperatures of operation, reactants, were not the only to be focuses dealing with organics the length of the reaction should also be considered. The research aimed to focus on the optimized fabrication of soy-polyol as intermediate to flexible foam polyurethane. Identify the use of the length of reaction to epoxidation reaction, and hydroxylation, and evaluates the correlation to the physical property of the foam product. [ABSTRACT FROM AUTHOR]

Boron Nitride (BN), a white crystalline inorganic material has equal number of Boron and Nitrogen atoms covalently bonded to each other. Atomically thin BN or exfoliated BN have better heat conducting properties, mechanical properties, optical and electrical properties. In the present work, BN has been exfoliated by ultrasonication method using an organic solvent N, N-Dimethyl Formamide commonly called as DMF. Hexagonal BN nanoparticles have been commonly used as perfect filler for polymer nanocomposites. To avoid the strong propensity of exfoliated layers to form clusters, surface modification is necessary using a suitable modifier. In the present work, hydroxylation of Boron Nitride Nanosheets (BNNS) was done using Sodium Hydroxide (NaOH) which has not been reported from the best of our knowledge. Hydroxyl group have been attached to the surface of BN for uniform dispersion of the nanofiller with the guest compound. [ABSTRACT FROM AUTHOR]

The unwieldiness of Fenton reaction on biodegradation of methyl orange (MO) by brown-rot fungus Gloeophyllum trabeum was investigated based on Fe2+-dependent reaction. The degradation of MO (final concentration 75 mg/L) was performed in mineral salt media with and without Fe2+ with incubation period at 0, 7, 14, 21, and 28 days. Degradation analysis was performed using UV-Vis Spectrophotometer and LC-TOF/MS. The highest MO degradation occurred during 28 days incubation, which approximately 46.67% and 38.89% in medium with and without Fe2+, respectively, indicated that the presence of Fe2+ enhanced MO degradation. C15H18N3O5S− and C17H22N3O7S− were the metabolic products of MO degradation in mineral salt medium with Fe2+. The MO pathway by G. trabeum was stated by termination on double bond of the azo group and followed by hydroxylation to C15H18N3O5S−, and then undergoes methylation to C17H22N3O7S−. This study assumed that Fenton reaction might be involved in MO biodegradation by G. trabeum. [ABSTRACT FROM AUTHOR]

A thermal property of hydroxylation of natural latex has been studied in this research. The effect of the hydroxylation conversion of the double bond to hydroxyl functionality of natural rubber in one pot solution using in-situ method. It was studied at different duration; 10, 20, 30, 40 and 50 hours of reaction. A mechanism for the hydroxylation of the natural rubber was also proposed. The result shows the optimum conversions of double bond to hydroxyl functionality was recorded highest at 40 hours and remain constant although the reaction was continued until 50hrs. Fourier Transform (FT) Raman spectroscopy was used to analyze the conversion. -1HNMR was used to confirm the formation of hydroxyl to support the peak from FT Raman spectra. Differential Scanning Calorimetric analysis was used to analyze the glass transition temperature (Tg) of modified and unmodified natural rubber. The result showed lower Tg in modified natural rubber compared to the unmodified natural rubber. On the other hand, the onset of thermal degradation of modified natural rubber recorded at 220°C compared to the unmodified natural rubber. [ABSTRACT FROM AUTHOR]

In this study, oil resistance properties, tensile strength and hardness properties of compounded hydroxylated Natural rubber (OONR) were evaluated. Oil and oxidation natural rubber (OONR) exhibited shorter cure time compared to the SMR-L and EPDM and recorded better crosslinks density. The performance of OONR clearly dominated the unmodified NR in terms of swelling to hydrocarbon oils and non-polar solvents. The OONR also depicted an increasing trend in hardness compared to the unmodified NR. However, the tensile strength of OONR vulcanizate was drastically decreased compared to SMR-L and EPDM compounded rubber. [ABSTRACT FROM AUTHOR]

Manufacturers of automotive repair finishes are tending to reduce more and more the level of volatile organic compounds in their paints in order to comply with increasingly strict environmental legislation. A high solid hydroxy acrylic resin was synthesised using CARDURA E10 and a type of hydroxyacrylic acid resin, its' acid value, hydroxylvalue, viscosity, structure, morphology was measured and film-forming properties after curing were characterised. The results show that the addition of CARDURA E10 in the copolymer composition significantly reduced the viscosity of the polymer system, improved the solid content of the resin and the physical properties of the coating. The hydroxyl acrylate resin with solid content of 90% and excellent comprehensive performance were successfully prepared by controlling the initiator dosage, polymerization temperature and monomer ratio. [ABSTRACT FROM AUTHOR]

Casava Starch film was prepared by casting method with different percentage of glycerol (0%, 0.5%, 1.0%, 1.5%, 2.0% and 2.5%) as plasticizer. The effect of glycerol content in starch film on mechanical and water absorption properties was studied. Results shows that the increase of glycerol content in cassava starch film had decrease the tensile strength, tensile modulus and increase the elongation of break properties. The result of water absorbency tended to increase for starch film with higher percentage of glycerol content. The incorporation of glycerol in cassava starch film had increase the water absorption ability due to increase of hydroxyl content contributed by glycerol. [ABSTRACT FROM AUTHOR]

Nanomaterials have become so popular thanks to new and unique properties differing them from their classic counterparts. One of the nanomaterials which is commonly used nowadays is graphene and its derivatives. This paper demonstrates the results of laboratory-scale experimental works on the influence of ultra highly concentrated single-layer Graphene Oxide (HCGO) on properties of water based-mud (WBM). GO is a mono-layer of sp²-hybridized carbon atoms derivatized by a mixture of carboxyl, hydroxyl and epoxy functionalities. Hydroxyl and epoxy groups are present in the highest concentrations on the surface of graphene oxide (GO) per sp³ hybridized carbon atoms, while the carboxyl and carbonyl groups are mainly found at the layer's edges, thanks to which GO can be easily dispersed in an aqueous environment. The results of our experimental works show that an addition of ultra highly concentrated single-layer Graphene Oxide (HCGO) modifies the microstructural properties of the fluid. HCGO reduces filtration, even if it is added at a relatively low concentration. The conducted analyses prove that HCGO in biopolymer-based drilling mud with biopolymer XCD reduces the growth of bacteria, fungi and yeasts. [ABSTRACT FROM AUTHOR]

Kurtosis is a statistical method which can be used to measure abnormality in a reading including measurement of Radio Frequency Inteference (RFI) levels on potential radio astronomical sites. The chosen sites were Jelebu, Behrang and Merang. The RFI surveys were done for hydroxyl spectral line windows (1600-1700 MHz). The simple kurtosis method used in this work has found that a higher kurtosis value indicated a less RFI affected site. The kurtosis values for the three chosen sites were 10.04, 7.94, and 5.89, respectively. For the overall spectrum (0-3Ghz), their kurtosis value were 5.22, 4.02 and 3.70, respectively. In both cases, the kurtosis values have been shown to be a good indicator of the levels of RFI at the chosen sites. [ABSTRACT FROM AUTHOR]

The paper deals with a simple kinetic model for a bimolecular chemical reaction. Specifically, a consistent relaxation—type approximation is introduced and briefly discussed, in comparison to previous models. It is shown that such BGK approach preserves the main features of the reactive Boltzmann equations, including conserved quantities, collision equilibria, law of mass action, and H—theorem. [ABSTRACT FROM AUTHOR]

Hybrid flexible polyurethane foams (HPU) were synthesized by using a hybrid hydroxilated adduct (HHA) based on renewable resources. In particular the HHA was obtained by dispersing cellulose wastes in colloidal silica at room temperature, pressure and humidity. The colloidal silica was selected for its ability of modifying the cellulose structure, by inducing a certain 'destructurization' of the crystalline phase, in order to allow cellulose to react with di-isocyanate for the final synthesis of the polyurethane foam. In fact, cellulose-polysilicate complexes are engaged in the reaction with the isocyanate groups. This study provides evidence of the effects of the colloidal silica on the cellulose structure, namely, a reduction of the microfiber cellulose diameter and the formation of hydrogen bonds between the polysilicate functional groups and the hydroxyl groups of the cellulose, as assessed by IR spectroscopy and solid state NMR. The HHA was added to a conventional polyol in different percentages (between 5 and 20%) to synthesize HPU in presence of catalysts, silicone surfactant and diphenylmethane diisocyanate (MDI). The mixture was expanded in a mold and cured for two hours at room temperature. Thermal analysis, optical microscopy and mechanical tests were performed on the foams. The results highlighted an improvement of thermal stability and a decrease of the cell size with respect neat polyurethane foam. Mechanical tests showed an improvement of the elastic modulus and of the damping properties with increasing HHA amount. [ABSTRACT FROM AUTHOR]

Information regarding the technology that went into the making of ancient archaeological ceramics can be used as an index of sophistication achieved by ancient civilizations. The phase transformations that occur in clays during dehydroxylation can be studied using infrared spectroscopy and it can be extended to determine the firing temperatures of ancient ceramic wares. The ratio of iron containing minerals can give clues regarding firing techniques employed. [ABSTRACT FROM AUTHOR]

The article presents the findings of a study regarding the investigation of nanostructured titania for drug delivery using Raman spectroscopy. It informs that drug delivery systems are used to enhance the stability of drugs and remove their side effects and describes the methods adopted to conduct the study. The study reveals that increase in the ratio of water and alkoxide will decrease surface hydroxylation and titania drug interaction.