The influence of sunflower and mustard leaf extracts on the germination of mustard seeds

The extracts from sunflower and mustard leaves were separated using SPE-Columns. The mustard seeds were germinated on water (24 h) and subsequently on crude extracts or separate fractions. The heat production rate was measured by isothermal calorimetry at 21°C and changes in seed cotyledons by FT-Raman spectroscopy. Crude extracts strongly inhibited seed germination. The water and ‘methanol’ fractions of mustard and sunflower extracts have a similar influence on the pattern of heat efflux. FT-Raman spectroscopy showed that extracts caused changes in cotyledons mainly in the content of fatty acids, carotenoids and flavonoids. Isothermal calorimetry and Raman spectroscopy are useful for the study of allelopathic interactions.     

Ozone reduction at Nafion modified Au electrode and the measurement of ozone concentration in highly resistive solutions

The mass transport and charge transfer kinetics of ozone reduction at Nafion coated Au electrodes were studied in 0.5 mol/L H2SO4 and highly resistive solutions such as distilled water and tap water. The diffusion coefficient and partition coefficient of ozone in Nafion coating are 1.78×10-6 cm2·s-1 and 2.75 at 25℃ (based on dry state thickness), respectively. The heterogeneous rate constants and Tafel slopes for ozone reduction at bare Au are 4.1×10-6 cm·s-1, 1.0×10-6 cm·s-1 and 181 mV, 207 mV in 0.5 mol/L H2SO4 and distilled water respectively and the corresponding values for Nafion coated Au are 5.5×10-6 cm·s-1, 1.1×10-6 cm·s-1 and 182 mV, 168 mV respectively. The Au microelectrode with 3 μm Nafion coating shows good linearity over the range 0-10 mmol/L ozone in distilled water with sensitivity 61 μA·ppm-1 ·cm-2, detection limit 10 ppb and 95% response time below 5 s at 25℃. The temperature coefficient in range of 11-30℃ is 1.3%.     

Synthesis and characterization of electroactive epoxy‐based interpenetrating polymer network gel

Epoxy/poly(N‐isopropylacrylamide) interpenetrating polymer network gels were prepared by varying the excess amine content in the matrix (0.4–0.6 equivalent). All the samples were characterized for mechanical properties and swelling in distilled water. The topography of polymer network was characterized by atomic force microscopy. The 0.5 equiv. excess amine sample exhibited optimum properties. Studies on swelling at different pH and electroactivity in different aqueous solution were performed. The bending angle observed during first 1 min was 1–5° at 3–10 V and a maximum of 25° in 5 min at 20 V for 0.5 equiv. excess amine in NaCl solution. Copyright © 2011 John Wiley & Sons, Ltd.     

Monitoring soybean seed germination by calorimetry

A method to monitor seed germination that combines isothermal calorimetry and imbibition measurements is reported. Individual seeds of three cultivars of soybean seeds (A7636RG, Munasqa and DM5.8RR) and one of radish were used. Imbibition curves were performed on individual seeds in a germination chamber at 25 °C. Calorimetric specific thermal power (p)–time (t) curves of germination were also obtained at 25 °C for 10 or more individual seeds after 30 min of equilibration of the system. Calorimetric experiments of germination in 5 mM KCN were performed to estimate specific imbibitions enthalpies (Δ_i h). The p–t curves could be extrapolated to t = 0 by relating the rate of water uptake as determined from imbibitions curves with p values. Then, p–t curves were integrated to determine the specific metabolic enthalpies Δh which in turn were related to the water content (WC) of seeds at the corresponding times. The method allows determination of specific enthalpy change due to germination, Δ_g h, which apparently is species related. Besides, the standard deviation (SD) of the Δ_g h value gives an indication of seed quality. On the other hand, the water content that seeds need to germinate and the moment at which seeds are fully imbibed can also be determined. This is very important when breeding new cultivars for water stress tolerance. The water content needed for each cultivar to germinate was 74, 57, 35 and 64% for soybean seeds cvs. A7636RG, Munasqa, DM5.8RR and radish, respectively.     

Solubility and some properties of aqueous solutions of fullerenol-d and composition of crystal hydrates

Method of isothermal saturation in ampules was used to study the solubility of fullerenol in distilled water in the temperature range 20–80°C and to determine the composition of its equilibrium crystal hydrates. The pycnometric technique was employed to examine how the density depends of the concentration of fullerenol solutions and the average molar and partial molar volumes of the components in solution at 25°C was calculated. The method of refractometry was used to study the dependence of the refractive index on the concentration of fullerenol solutions and the specific refraction of the solutions was calculated.     

Extraction of nutraceuticals from milk thistle

Milk thistle contains compounds that display hepatoxic protection properties. We examined the batch extraction of silymarin compounds from milk thistle seed meal in 50, 70, 85, and 100°C water as a function of time. After 210 min of extraction at 100°C, the yield of taxifolin was 1.2 mg/g of seed, a 6.2-fold increase over the results obtained in a Soxhlet extraction with ethanol on pretreated (defatted) seeds. Similarly, the yield of silychristin was 5.0 mg/g of seed, a 3.8-fold increase. The yields of silybinin A and silybinin B were 1.8 and 3.3 mg/g of seed, respectively, or roughly 30% of the Soxhlet yield. The ratios of the extracted compounds, and particularly the ratios at long extraction times, showed that the more polar compounds (taxifolin and silychristin) were preferentially extracted at 85°C, while the less polar silybinin was favored at 100°C.     

Thermal transition and decomposition properties of pH- and phosphate-induced defatted soybean meals

Defatted soybean meal is a popular raw material for soybean protein products. Thermal properties of soybean meal, which is vital for its application in extruded texturized soybean protein, are influenced by storage time and processing temperature. Thus, low-temperature defatted soybean meal (LSM), low-temperature defatted one-year-stored-soybean meal (LSSM) and high-temperature defatted soybean meal (HSM) were selected to investigate the thermal transition and decomposition properties by pH induction with phosphate using differential scanning calorimetry and thermal gravimetric analysis. The results showed that the peak temperature of 11S (glycinin) in phosphate buffer at pH 7 is significantly higher than that in deionized water. Break temperatures of LSM and LSSM at around 110 °C in deionized water are significantly higher than that in phosphate buffer at pH 7; however, the break temperature of LSM at 300 °C in deionized water is significantly lower than that in phosphate buffer at pH 7. In contrast to LSM, ?H of LSSM in phosphate buffer at pH 7 is significantly lower than in deionized water. It is thus concluded that phosphate stabilizes the soybean protein quaternary structure, enhances protein–protein interactions and weakens protein-water interactions. Protein association occurs in LSSM during soybean storage, while HSM protein appears to be insensitive to these changes.     

Analysis of six aromatic amines stability in workplace measurement

For aromatic amine determination in workplaces, stabilities of six types of carcinogenic aromatic amines (2,4-diaminotoluene, 4,4'-diamino-3,3'-dimethyldiphenylmethane, o-tolidine, 3,3'-dichlorobenzidine, 4,4'-methylenebis(2-chloroaniline), and o-dianisidine) were evaluated with air or argon gas bubbling for 45 min in aqueous solution under light irradiation (desk lamp) and heating conditions. Gas chromatography–mass spectrometry (GC–MS) was used to identify and quantify the aromatic amines. The following conditions were selected: temperature program 70°C (1 min), 7 grad/min up to 120°C (1 min), 10 grad/min up to 300°C (5 min), carrier gas flow rate 1.0 mL/min. 3,3'-Dichlorobenzidine concentration decreased by approximately 10% after irradiation with a desk lamp for 45 min in distilled water, and a monochloro compound was detected by GC–MS. The other aromatic amines were rarely different from the 0-min concentration. The shielding prevented the decomposition of 3,3'-dichlorobenzidine in distilled water.     

Study on the initial evaporation rates of distilled sulphur mustard (HD) in concrete using wind tunnel and TD-GC/MSD: effect of drop size and temperature

In this paper, we demonstrate a robust, analytical method for the study of the initial evaporation rates of distilled sulphur mustard (HD) in concrete at various drop sizes and temperatures. We used a 5-cm wind tunnel and thermal desorption (TD) in connection with gas chromatograph and mass spectrometry detection (GC/MSD). Drops of neat HD, ranging in sizes of 1, 3, 6 and 9 µL, were applied to small concrete coupons. The temperatures were either 18°C, 25°C, 35°C or 50°C. The drop of HD rapidly spread in concrete upon its release. The initial evaporation rates of the drop of HD were analysed by TD in conjunction with GC/MSD. The results showed that the initial evaporation rates increased while HD spread over the surface of concrete, then decreased as the contamination was over. We also found that the initial evaporation rates of the drop of HD in concrete are linearly proportional to drop size and temperature. In particular, drop size or spreading factor has a more pronounced effect on the initial evaporation rates of the drop of HD in concrete than temperature.     

Standardisation of cooking and conditioning methods for preparation of quick cooking germinated brown rice

Quick cooking germinated brown rice (QCGBR) is a novel convenient food product with valuable health benefits. Different cooking and conditioning methods were studied for standardisation of its preparation process. Freshly harvested paddy of Prativa variety was milled in rubber roll sheller to get brown rice which was soaked in demineralised water at 30 ​± ​2 ​°C for 12 ​h followed by 24 ​h of germination in an incubator maintained at 27 ​± ​1 ​°C temperature and 85–90% relative humidity to obtain germinated brown rice. The germinated brown rice was immediately cooked using three different cooking methods such as atmospheric cooking at normal ambient pressure, pressure cooking with water in a domestic pressure cooker at 1 ​bar gauge pressure and pressure steaming (without water) with steam at 1 ​bar gauge pressure to predetermined cooking time. The cooked samples after washing were then conditioned by keeping them at 4 ​°C for 24 ​h (refrigerated storage) or −10 ​°C for 24 ​h (frozen storage) in a house hold refrigerator. The stored samples were taken out after 24 ​h and tempered for 1 ​h followed by drying in a tray dryer at 90 ​°C to obtain the quick cooking germinated brown rice. The samples obtained from different cooking and conditioning methods were analysed for cooking quality, physico-chemical parameters, damaged grain percentage, GABA content and sensory attributes to standardise the cooking and conditioning methods. Cooking time, water uptake ratio, solid loss and volume expansion ratio of quick cooking germinated brown rice varied significantly with cooking and conditioning methods of its preparation (p ​< ​0.05). Though frozen conditioning resulted in lowest cooking time, it was not accepted by the sensory panel due to high damaged grain percentage, distorted shape and softness after cooking. The QCGBR obtained by pressure cooking method followed by refrigerated conditioning resulted in highest sensory score.     

Glycosidases of turnip leaf tissues

Four myrosinase (β-thioglucosidase EC. 3.2.3.1) and seven disaccharase (β-fructofuranosidase, EC. 3.2.1.26) isoenzymes were isolated from turnip leaves. The most active enzymes were isolated in pure form. Myrosinase and disaccharase mol wt was 62.0 × 10³ and 69.5 × 10³ dalton, respectively, on the basis of gel filtration on Sephadex G-200. Myrosinase pH profile showed high activity between pH 5 and 7 with the optimum at pH 5.5. The purified enzyme was heat-stable for 60 min at 30°C with only loss of 24% of activity. Its activity is strongly inhibited (100%) by Pb²⁺, Ba²⁺, Cu²⁺ and Ca²⁺ ions, and activated (70%) by EDTA at 0.04M. The pure enzyme failed to hydrolyze amylose, glycogen, lactose, maltose, and sucrose. TheK _m andV _max values of myrosinase using sinigrin as specific substrate was 0.045 mM and 2.5 U, respectively. The maximal activity of disaccharase enzyme was obtained at pH 4–5 and 35–37°C. The enzyme was heat-stable at 30°C for 30 min with only 10% loss of its activity. Its activity is strongly activated (70–240%) by Ca²⁺, Ba²⁺, Cu²⁺, and EDTA at 0.01M. The enzyme activity is specific to the disaccharide sucrose and failed to hydrolyze other disaccharides (maltose and lactose). TheK _m andV _max of disaccharase were 0.123 mM and 3.33 U, respectively.     

Degradation of dibutyltin in sea water by pyoverdins isolated from Pseudomonas chlororaphis

The yellow compounds pyoverdins were isolated from Pseudomonas chlororaphis, which was isolated from mud in Japan. Degradation of tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) by pyoverdin (20 mg) was carried in sea water (30 ml) containing a 6 µg l^?1 concentration of TBT, DBT, and MBT at 24 °C for 24 h in aerobic conditions. TBT, DBT, and MBT in sea water were analyzed by gas chromatography–mass spectrometry in selected ion monitoring mode. DBT in sea water was degraded to MBT by pyoverdins isolated from P. chlororaphis. However, TBT and MBT in sea water was not degraded by pyoverdins. The optimum degradation of DBT in sea water was at pH 4.8–8.2, at a temperature 25–30 °C. Copyright © 2002 John Wiley & Sons, Ltd.     

Protease A from cotton seeds. Isolation and purification of the enzyme

Protease A has been isolated in the homogeneous state from dormant seeds of cotton plants of the Tashkent-I variety. A scheme is proposed for the isolation and purification of the enzyme which includes the following stages: extraction of the defatted seeds with 0.1 M phosphate buffer, pH 7.4; precipitation of the protein with ammonium sulfate at 60% saturation; desalting by dialysis; and ionexchange chromatography on a column containing CM- and DEAE-celluloses. The molecular weight of the enzyme has been determined as 60,000. The enzyme efficiently hydrolyzes azocasein and the 7S and 11S reserve proteins of cotton seeds. Its maximum activity appears at pH 6.4–7.4 and a temperature of 35–40°C; it is not activated by sulfhydryl reagents and loses its activity in the presence of diisopropyl phosphorofluoridate. The assumption is made that protease A belongs to the serine type of trypsin-like proteases.     

Swelling Behavior of N-t-butylacrylamide Copolymer and Terpolymers

Copolymers and terpolymers of N-t-butylacrylamide (TBA) with 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and N-hydroxy methyl acrylamide (NHMAAM) were prepared by solution polymerization in a 1:1 (v/v) mixture of methanol and water at 50 °C keeping the TBA content in the feed constant at 60% based on mole ratio. The contents of AMPS or NHMAAM used for the preparation of TBA-AMPS and TBA-NHMAAM copolymers were 40 mole %. Molar percentages of AMPS and NHMAAM monomers in the feed for the preparation of TBA-AMPS-NHMAAM terpolymers were varied as 10:30, 20:20, and 30:10, respectively. The effects of temperature, AMPS and crosslinker contents, and the drying of swollen gels on the swelling behavior of ionic and non-ionic TBA gels were investigated in distilled water between 10–50 °C and in buffer solutions having various pHs (1.9, 3.1, 5.6, 7.1, and 9.8) with constant ionic strength of 0.08 M at 20 °C using both the dry and the swollen forms of gels. The chemical structures and microscopic morphologies of the polymers were investigated by FTIR and SEM, respectively.     

Weak transverse magnetic field effect on the viscosity of water at several temperatures

Experiments performed at 10, 20, 25, 30, 35, 40 and 50°C show that a transversally applied magnetic field H (H ranges from 0 to 12 kG) weakly increases the viscosity of distilled water. The largest value of this increase occurs at the applied magnetic field strength of 12 kg at the vicinity of a temperature of 25°C.     

Degradation of triphenyltin compounds in sea water by pyoverdins from Pseudomonas chlororaphis

The yellow compound species pyoverdin was isolated from Pseudomonas chlororaphis. Degradation of triphenyltin (TPT) by pyoverdin (20 mg) was carried in distilled water (30 ml) containing a 6 µg l^?1 concentration of TPT at 20 °C for 96 h in aerobic conditions. The organotins in water and sea water were analyzed by gas chromatograph–mass spectrometry in selected ion mode. TPT and diphenyltin (DPT) in sea water were degraded to monophenyltin (MPT) with pyoverdins isolated from P. ­chlororaphis. Degradation of TPT in sea water increased with increasing temperature between 4 and 37 °C. Optimum degradation of TPT in sea water was at pH 7–8.5. Degradation of TPT and DPT in distilled water can be faster than in sea water. Also, degradation of TPT in both water and sea water was faster than that of DPT. Tributyltin, dibutyltin, monobutyltin and MPT in water and sea water were not degraded by pyoverdins isolated from P. chlororaphis. Copyright © 2001 John Wiley & Sons, Ltd.     

Epoxy Coatings with Low Surface Energy from Powdered Compounds Modified with Finely Dispersed Polytetrafluoroethylene Particles

Highly hydrophobic epoxy coatings with the surface energy as low as 14.5 mJ m^–2 and contact angles with water of 120°–150° were prepared from powdered compounds modified with less than 2 wt % finely dispersed polytetrafluoroethylene particles by dry mixing. As shown by scanning electron microscopy, EDX microanalysis, and atomic-force microscopy, the film formation at 180°С and formation of a polymer network matrix are accompanied by predominant migration of polytetrafluoroethylene particles to the air/coating interface, leading to gradient distribution of fluorine across the film and significant enrichment of the coating surface with fluorine. By varying the polytetrafluoroethylene content, it is possible to obtain hydrophobic coatings with satisfactory physicomechanical properties, smooth or rough surface, including micrometric and nanometric roughness, and different surface energy.     

The influence of temperature and different storage conditions on the stability of supersulphated cement

The stability of Supersulphated Cement (SSC) is investigated at 95°C when subjected to relative humidities of 100, 53 and 11% of water vapour. Previously [1] investigations at 25, 50, 75°C under the same conditions of humidity reported the stability of ettringite, one of the initial hydration products. At 95°C, decomposition of ettringite, is found at all humidities and is rapid at 100% relative humidity. The hydration products of cement pastes at a water cement ratio of 0.27 were determined by thermogravimetry (TG) and X-ray diffraction (XRD). The formation of the hydragarnet, plazolite is recorded during the decomposition/dehydration process enhanced by possible carbonation. Rehydration studies on the products after storage for up to 9 months were carried out using distilled water and the samples tested for ettringite content. It is concluded that ettringite in SSC is inherently unstable at 95°C.     

Comparison of Volatile Organic Compounds of Thymus Vulgaris Using Hydrodistillation and Headspace Solid Phase Microextraction Gas Chromatography Mass Spectrometry

Essential oil of aerial parts of Tymus vulgaris L. from Babaaman montains of Iran were isolated by hydrodistillation with an average oil yield 1.9 w/w%. The components of the oil were identified by gas chromatography mass spectrometry. On a separate experiments the compositions of volatile emission of the plant were studied by headspace solid phase microextraction and gas chromatography mass spectrometry. The tempratures used during the sample preparation were 25°C and 50°C. In order to determine the effect of solvent (water) on the separation, the experiments were done in the presence and absence of distilled water in the extraction vial at the tempratures mentioned above. Ten majour components were obtained in four different experimental headspace solid phase microextraction conditions and the hydrodistillation methods from the plant. Thymol was found to be the most abundant costituent (27.2–73.09%), follwoed by p‐cymene (6.86–31.76%), γ‐terpinene (1.02–9.26%), myrcene (0.05–8.84%), α‐pinene (0.25–6.63%), caryophyllene (3.09–5.56%), thymol methyl ether (0.99–2.97%), thymolacetate (0.11–2.05%), carvacrol (0.49–1.70%) and α‐cadinol (0.38–1.10%).     

Mechanical properties of perfluoro sulfonated acids: The role of temperature and solute activity

Water sorption and mechanical properties of perfluoro sulfonated acids (PFSAs), Aquivion and Nafion, are compared under environmentally controlled conditions from 25 to 120 °C and water activities of 0–0.95. Under dry conditions Nafion and Aquivion have thermal transitions at 60 °C and 95 °C, respectively, where the elastic modulus decreases rapidly with increasing temperature. Below their thermal transition temperatures water sorption plasticizes both PFSAs; the elastic moduli decrease with increasing water activity. Above the thermal transition water sorption stiffens both polymers; increasing the water activity from 0 to 0.01 increases the elastic moduli by a factor >10. Plasticization and stiffening are reversible with changing water activity at constant temperature. The thermal transition in PFSAs is suggested to result from reversible clustering of ionic groups. The higher thermal transition temperature for Aquivion is suggested to reduce the risk of membrane thinning and failure due to creep. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2013, 51, 915–925