WorldWideScience

Sample records for leaf chemical properties

  1. Characterization of anticancer, antimicrobial, antioxidant properties and chemical compositions of Peperomia pellucida leaf extract.

    Science.gov (United States)

    Wei, Lee Seong; Wee, Wendy; Siong, Julius Yong Fu; Syamsumir, Desy Fitrya

    2011-01-01

    Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then characterized using α, α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging method and the chemical compositions were screened and identified using gas chromatography-mass spectrometry (GC-MS). The results of present study indicated that P. pellucida leaf extract possessed anticancer activities with half maximal inhibitory concentration (IC(50)) of 10.4 ± 0.06 µg/ml. The minimum inhibitory concentration (MIC) values were ranged from 31.25 to 125 mg/l in which the plant extract was found to inhibit the growth of Edwardsiella tarda, Escherichia coli, Flavobacterium sp., Pseudomonas aeruginosa and Vibrio cholerae at 31.25 mg/l; Klebsiella sp., Aeromonas hydrophila and Vibrio alginolyticus at 62.5 mg/l; and it was able to control the growth of Salmonella sp. and Vibrio parahaemolyticus at 125 mg/l. At the concentration of 0.625 ppt, the plant extract was found to inhibit 30% of DPPH, free radical. Phytol (37.88%) was the major compound in the plant extract followed by 2-Naphthalenol, decahydro- (26.20%), Hexadecanoic acid, methyl ester (18.31%) and 9,12-Octadecadienoic acid (Z,Z)-, methyl ester (17.61%). Findings from this study indicated that methanol extract of P. pellucida leaf possessed vast potential as medicinal drug especially in breast cancer treatment.

  2. Characterization of Anticancer, Antimicrobial, Antioxidant Properties and Chemical Compositions of Peperomia Pellucida Leaf Extract

    Directory of Open Access Journals (Sweden)

    Desy Fitrya Syamsumir

    2011-10-01

    Full Text Available Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium assay against human breast adenocarcinoma (MCF-7 cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then characterized using α, α-diphenyl-β-picrylhydrazyl (DPPH radical scavenging method and the chemical compositions were screened and identified using gas chromatography-mass spectrometry (GC-MS. The results of present study indicated that P. pellucida leaf extract possessed anticancer activities with half maximal inhibitory concentration (IC50 of 10.4±0.06 µg/ml. The minimum inhibitory concentration (MIC values were ranged from 31.25 to 125 mg/l in which the plant extract was found to inhibit the growth of Edwardsiella tarda, Escherichia coli, Flavobacterium sp., Pseudomonas aeruginosa and Vibrio cholerae at 31.25 mg/l; Klebsiella sp., Aeromonas hydrophila and Vibrio alginolyticus at 62.5 mg/l; and it was able to control the growth of Salmonella sp. and Vibrio parahaemolyticus at 125 mg/l. At the concentration of 0.625 ppt, the plant extract was found to inhibit 30% of DPPH, free radical. Phytol (37.88% was the major compound in the plant extract followed by 2-Naphthalenol, decahydro- (26.20%, Hexadecanoic acid, methyl ester (18.31% and 9,12-Octadecadienoic acid (Z,Z-, methyl ester (17.61%. Findings from this study indicated that methanol extract of P. pellucida leaf possessed vast potential as medicinal drug especially in breast cancer treatment.

  3. Anatomical and Chemical Characteristics of a Rolling Leaf Mutant of Rice and Its Ecophysiological Properties

    Institute of Scientific and Technical Information of China (English)

    BAI Lei; DUAN Zhuang-qin; WANG Jun-min; AN Li-zhe; ZHAO Zhi-guang; CHEN Kun-ming

    2008-01-01

    The anatomical and chemical characteristics of a rolling leaf mutant (r/m) of rice (Oryza sativa L.) and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with the wild type (WT),the areas of whole vascular bundles and xylem as well as the ratios of xylem area/whole vascular bundles area and xylem area/phloem area were higher in r/m, whereas the area and the width of foliar bulliform cell were lower. The Fourier transform infrared (FTIR) microspectroscopy spectra of foliar cell walls differed greatly between r/m and WT. The r/m exhibited lower protein and polysaccharide contents of foliar cell walls. An obvious reduction of pectin content was also found in r/m by biochemical measurements. Moreover, the rate of photosynthesis was depressed while the conductance of stoma and the intercellular CO2 concentration were enhanced in rim. The PTS fluorescence, which represents the ability of apoplastic transport, was 11% higher in r/m than in WT. These results suggest that the changes in anatomical and chemical characteristics of foliar vascular bundles, such as the reduction of proteins, pectins, and other polysaccharides of foliar cell walls, participate in the leaf rolling mutation, and consequently lead to the reduced photosynthetic dynamics and apoplastic transport ability in the mutant.

  4. High Throughput In vivo Analysis of Plant Leaf Chemical Properties Using Hyperspectral Imaging

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    Piyush Pandey

    2017-08-01

    Full Text Available Image-based high-throughput plant phenotyping in greenhouse has the potential to relieve the bottleneck currently presented by phenotypic scoring which limits the throughput of gene discovery and crop improvement efforts. Numerous studies have employed automated RGB imaging to characterize biomass and growth of agronomically important crops. The objective of this study was to investigate the utility of hyperspectral imaging for quantifying chemical properties of maize and soybean plants in vivo. These properties included leaf water content, as well as concentrations of macronutrients nitrogen (N, phosphorus (P, potassium (K, magnesium (Mg, calcium (Ca, and sulfur (S, and micronutrients sodium (Na, iron (Fe, manganese (Mn, boron (B, copper (Cu, and zinc (Zn. Hyperspectral images were collected from 60 maize and 60 soybean plants, each subjected to varying levels of either water deficit or nutrient limitation stress with the goal of creating a wide range of variation in the chemical properties of plant leaves. Plants were imaged on an automated conveyor belt system using a hyperspectral imager with a spectral range from 550 to 1,700 nm. Images were processed to extract reflectance spectrum from each plant and partial least squares regression models were developed to correlate spectral data with chemical data. Among all the chemical properties investigated, water content was predicted with the highest accuracy [R2 = 0.93 and RPD (Ratio of Performance to Deviation = 3.8]. All macronutrients were also quantified satisfactorily (R2 from 0.69 to 0.92, RPD from 1.62 to 3.62, with N predicted best followed by P, K, and S. The micronutrients group showed lower prediction accuracy (R2 from 0.19 to 0.86, RPD from 1.09 to 2.69 than the macronutrient groups. Cu and Zn were best predicted, followed by Fe and Mn. Na and B were the only two properties that hyperspectral imaging was not able to quantify satisfactorily (R2 < 0.3 and RPD < 1.2. This study suggested

  5. CHEMICAL PROPERTIES.

    African Journals Online (AJOL)

    However, the amount of soil organic matter and total nitrogen content was. T DIFFERENT HOURS ... burning such as improvement in soil physical ... chemical properties. The aim is to find .... Humid Tropics with particular reference to. Nigeria.

  6. Oxidative Stability and Physico-chemical Properties of Meat from Broilers Fed with Dietary Neem Leaf Powder, Spirulina and their Combination

    Directory of Open Access Journals (Sweden)

    Ravi KILLI

    2015-12-01

    Full Text Available This 6 week study was conducted to evaluate the antioxidant potential, maintaining quality and sensory properties of broiler meat from birds fed on dietary neem leaf powder (NLP. A total of 90 Vencobb broiler chicks were randomly allotted to 6 groups of 15 birds in each. Dietary treatments consisted of normal diet (control Group I, feed containing terramycin-200 (TM-200* at the concentration of 0.05% (Group II, feed containing NLP of 0.2% (Group III, feed containing NLP of 0.2% and spirulina of 1% (Group IV, feed containing TM-200 at 0.05% and spirulina of 1% (Group V and feed containing spirulina of 1% (Group VI. At the end of the experiment liver, kidney and muscle samples were collected to evaluate the tissue peroxidation (TBARS and protein carbonyls and antioxidant markers (SOD. Physico-chemical quality determinants of both fresh and preserved meat viz. extract release volume (ERV, water holding capacity (WHC and pH were also studied. TBARS protein carbonyls indicated a significant (P < 0.05 decrease in all the treated groups when compared to control. Superoxide dismutase levels were found to be significantly increased in all the treated groups, in all the tissues collected. Compared to control group, favorable physico-chemical quality determinants were recorded in all the treated groups. The sensory attributes did not show significant (P < 0.05 differences for color, flavor, juiciness, tenderness and overall acceptability. This study indicates enhanced stress tolerance levels, improved meat quality with unaffected consumer acceptance levels of the meat observed in the study, from broilers fed with neem and spirulina either alone or in combinationsș this points out that neem at 0.2% level can be used in poultry diets instead of antibiotic growth promoters (AGP.

  7. Effect of jasmonic acid elicitation on the yield, chemical composition, and antioxidant and anti-inflammatory properties of essential oil of lettuce leaf basil (Ocimum basilicum L.).

    Science.gov (United States)

    Złotek, Urszula; Michalak-Majewska, Monika; Szymanowska, Urszula

    2016-12-15

    The effect of elicitation with jasmonic acid (JA) on the plant yield, the production and composition of essential oils of lettuce leaf basil was evaluated. JA-elicitation slightly affected the yield of plants and significantly increased the amount of essential oils produced by basil - the highest oil yield (0.78±0.005mL/100gdw) was achieved in plants elicited with 100μM JA. The application of the tested elicitor also influenced the chemical composition of basil essential oils - 100μM JA increased the linalool, eugenol, and limonene levels, while 1μM JA caused the highest increase in the methyl eugenol content. Essential oils from JA-elicited basil (especially 1μM and 100μM) exhibited more effective antioxidant and anti-inflammatory potential; therefore, this inducer may be a very useful biochemical tool for improving production and composition of herbal essential oils.

  8. Antioxidant properties of fermented mango leaf extracts.

    Science.gov (United States)

    Park, Anna; Ku, Taekyu; Yoo, Ilsou

    2015-01-01

    Antioxidant properties of mango (Mangifera indica) leaves were evaluated. Hydroalcoholic leaf extracts that were lyophilized were subsequently fermented with either Lactobacillus casei or effective microorganisms (EM) such as probiotic bacteria and/or other anaerobic organisms. Antioxidant properties were measured as a function of the mango leaf extract concentration in the fermentation broth. Tests for radical scavenging using the 1,1-diphenyl-2-picrylhydrazyl radical showed higher antioxidant activity for Lactobacillus- and EM-fermented mango leaf extracts than for the synthetic antioxidant butylated hydroxytoluene. Antioxidant activity generally increased with increasing fermented extract concentration as did the fermented extracts' polyphenol and flavonoid contents. Fermented extracts reduced reactive oxygen species generation by lipopolysaccharide in RAW 264.7 cells when measured via fluorescence of dichlorodihydrofluorescein acetate treated cells using flow cytometry. RAW 264.7 cells also showed a concentration-dependent cytotoxic effect of the fermented extracts using the 3-(4,5-dimethylthialol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inhibition of mushroom tyrosinase activity as well as nitrite scavenging by the fermented extracts increased as fermented extract concentrations increased. Tyrosinase activity was assayed with 3,4-dihydroxyphenylalanine as substrate. Nitrite scavenging was assessed via measurement of inhibition of chromophore production from nitrite-naphthylamine-sulfanilic acid mixtures. The antioxidant properties of fermented mango leaf extracts suggest the fermented extracts may be useful in developing health food and fermentation-based beauty products.

  9. Chemical profile and antinociceptive efficacy of Rheedia longifolia leaf extract.

    Science.gov (United States)

    Santos, José A A; Calheiros, Andrea; Nascimento, Diogo D; Bérenger, Ana Luiza R; Amendoeira, Fábio C; Castro-Faria-Neto, Hugo C; Figueiredo, Maria Raquel; Alves, Luiz A; Frutuoso, Valber da Silva

    2011-09-01

    Different species of the family Clusiaceae, including Rheedia longifolia, are used in folk medicine to treat inflammatory diseases. This family is largely distributed in tropical and subtropical areas of Brazil, but their chemical and pharmacological properties have been the subject of a few studies. In previous studies, we found that the aqueous extract from R. longifolia leaves presented important anti-inflammatory and analgesic activity. We investigated the chemical profile of R. longifolia and characterized the pharmacological effect of different chemically identified fractions in pharmacological models of neurogenic and inflammatory nociception. The pharmacological tests showed that oral treatment with aqueous crude extract and fractions of methanol extract of R. longifolia leaf induced a significant antinociceptive effect using von Frey filaments. In addition, the most polar fractions presented antinociceptive activity in a neurogenic model of nociception (capsaicin model). The chromatographic analysis indicated the presence of bisflavonoids in the fractions obtained from the methanol extract. These results suggest that bisflavonoids found in methanol-extracted fractions are involved in the inhibition of inflammatory and neurogenic nociception. It is important that the R. longifolia aqueous extract treatment inhibited ulcer formation induced by indomethacin, suggesting an anti-ulcerogenic activity closely associated with its analgesic effect.

  10. Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

    Directory of Open Access Journals (Sweden)

    Hans J. Ensikat

    2011-03-01

    Full Text Available Lotus leaves have become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the ‘Lotus effect’. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and are the basis for the perfection and durability of the water repellency. A reason for the optimization, particularly of the upper side of the lotus leaf, can be deduced from the fact that the stomata are located in the upper epidermis. Here, the impact of rain and contamination is higher than on the lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves.

  11. Superhydrophobicity in perfection: the outstanding properties of the lotus leaf.

    Science.gov (United States)

    Ensikat, Hans J; Ditsche-Kuru, Petra; Neinhuis, Christoph; Barthlott, Wilhelm

    2011-01-01

    Lotus leaves have become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the 'Lotus effect'. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and are the basis for the perfection and durability of the water repellency. A reason for the optimization, particularly of the upper side of the lotus leaf, can be deduced from the fact that the stomata are located in the upper epidermis. Here, the impact of rain and contamination is higher than on the lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves.

  12. Properties of ligno-cellulose ficus religiosa leaf fibers

    CSIR Research Space (South Africa)

    Reddy, KO

    2010-04-01

    Full Text Available Religiosa Leaf Fibers International Journal of Polymers and Technologies • 2(1) January-April 2010 29 I J P T © Serials Publications * Corresponding author: E-mail: arajulu@rediffmail.com Properties of Ligno-cellulose Ficus Religiosa Leaf Fibers K. Obi... was also studied and the results are reported in this paper. MATERIALS AND METHODS Materials Extracted ficus leaf fibers, sodium hydroxide pellets (Merk, India), benzene, sodium chlorite, acetic acid, sodium bisulphate and ethanol (S...

  13. The times they are a-changin': seasonal variations of leaf spectra in relation with leaf biochemical and biophysical properties

    Science.gov (United States)

    Yang, X.; Tang, J.; Mustard, J. F.

    2013-12-01

    Leaf traits such as chlorophyll concentration, leaf mass per area (LMA), and mesophyll cell area exposed to the internal area space per leaf area (Ames/A) are key biochemical or biophysical properties to understand the vegetation functioning. Measurements of leaf spectra provided a non-destructive way to estimate those parameters. Many studies have linked leaf spectra with some of leaf traits successfully, but the understanding of spectra-traits relationship is still limited in the following aspects: (1) how does the ability of spectra to estimate leaf traits change (or not) throughout the growing season? (2) How to quantify leaf internal structure with leaf spectra? (3) What are the leaf traits that contribute to the structure parameter in leaf reflectance model such as PROSPECT? To answer the questions above, we conducted weekly measurements of leaf spectra, leaf biochemical properties (chlorophyll, carotenoids, water, and total carbon and nitrogen) and biophysical properties (LMA and internal structures) during the growing seasons of year 2011 and 2012. We found that leaf traits express themselves in the leaf spectra at different wavelengths; the relationships between spectra and leaf traits vary throughout the season. Leaf internal structure parameters are mostly related to the near-infrared reflectance. The structure parameter (N) in PROSPECT is related to the Ames/A, LMA, and water content. Our results have broad implications for using hyperspectral imagers/sensors to monitor vegetations that have clear seasonal patterns.

  14. Chemical properties of mendelevium

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1980-11-01

    Even with the most intense ion beams and the largest available quantities of target isotope, about 10/sup 6/ atoms at a time is all the Md that can be produced for chemical studies. This lack of sufficient sample size coupled with the very short lifetimes of the few atoms produced has severely restricted the gathering and the broadness of our knowledge concerning the properties of Md and the heavier elements. To illustrate, the literature contains a mere eleven references to the chemical studies of Md, and none of these deal with bulk properties associated with the element bound in solid phases. Some of these findings are: Md was found to be more volatile than other actinide metals which lead to the belief that it is divalent in the metallic state; separation of Md from the other actinides can be accomplished either by reduction of Md/sup 3 +/ to the divalent state or by chromatographic separations with Md remaining in the tripositive state; extraction of Md/sup 2 +/ with bis(2-ethylhexyl)phosphoric acid is much poorer than the extraction of the neighboring tripositive actinides; attempts to oxidize Md/sup 3 +/ with sodium bismuthate failed to show any evidence for Md/sup 4 +/; reduction potential of Md/sup 3 +/ was found to be close to -0.1 volt; Md/sup 3 +/ can be reduced to Md(Hg) by sodium amalgams and by electrolysis; the electrochemical behavior of Md is very similar to that of Fm and can be summarized in the equation, Md/sup 2 +/ + 2e/sup -/ = Md(Hg) and E/sup 0/ = -1.50 V.; and Md cannot be reduced to a monovalent ion with Sm/sup 2 +/.

  15. Silicified structures affect leaf optical properties in grasses and sedge.

    Science.gov (United States)

    Klančnik, Katja; Vogel-Mikuš, Katarina; Gaberščik, Alenka

    2014-01-05

    Silicon (Si) is an important structural element that can accumulate at high concentrations in grasses and sedges, and therefore Si structures might affect the optical properties of the leaves. To better understand the role of Si in light/leaf interactions in species rich in Si, we examined the total Si and silica phytoliths, the biochemical and morphological leaf properties, and the reflectance and transmittance spectra in grasses (Phragmites australis, Phalaris arundinacea, Molinia caerulea, Deschampsia cespitosa) and sedge (Carex elata). We show that these grasses contain >1% phytoliths per dry mass, while the sedge contains only 0.4%. The data reveal the variable leaf structures of these species and significant differences in the amount of Si and phytoliths between developing and mature leaves within each species and between grasses and sedge, with little difference seen among the grass species. Redundancy analysis shows the significant roles of the different near-surface silicified leaf structures (e.g., prickle hairs, cuticle, epidermis), phytoliths and Si contents, which explain the majority of the reflectance and transmittance spectra variability. The amount of explained variance differs between mature and developing leaves. The transmittance spectra are also significantly affected by chlorophyll a content and calcium levels in the leaf tissue.

  16. [Study on chemical constituents from twig and leaf of Juniperus sabina].

    Science.gov (United States)

    Xu, Fang; Zhao, Jun; Xu, Fang; Ji, Teng-fei; Ma, Long

    2013-12-01

    To isolate and determine chemical constituents from twig and leaf of Juniperus sabina. Five compounds were isolated and purified by extraction and different kinds of column chromatography. The structures were determined on the basis of the physicochemical properties and spectral analysis. The structures were elucidated as quercetin-3-O-(6"-O-acetyl)-beta-D-glucopyranoside(1), hypolaetin-7-O-beta-D-glucopyranoside(2), isoquercetin(3),4-epi-abietic acid(4), beta-sitosterol(5). Compounds 1-3 are obtained from Juniperus genus for the first time.

  17. Leaf Chemical and Structural Traits Control Variation in Leaf Litter Water Absorption

    Science.gov (United States)

    Talhelm, A. F.; Smith, A. M.

    2016-12-01

    The ability of plant litter to absorb moisture from precipitation or atmospheric humidity is well known to vary among plant species and is an important trait for wildland fire science, hydrology, and litter decomposition. This variation among species is thought to be function of litter physical and chemical traits, but there has been little systematic investigation of these relationships. To test the influence of chemical and structural traits on water absorption, we collected recently senesced leaves of 23 temperate species that represented a range of habitats and plant functional types and then quantified a suite of biochemical (gross energy, lignin, lipid, and ash content), elemental (C, N, O, and H %, C oxidation state), and structural (specific leaf area) characteristics as well as the maximum water absorption capacity of whole leaves and the amount of water vapor absorbed by whole leaves and finely-ground leaves. Maximum water absorption of whole leaves was positively related to both average C oxidation state (r = 0.55) and specific leaf area (r = 0.58) and negatively related to lignin (r = -0.67) and energy content (r = -0.57). The amount water vapor absorbed over an hour after being removed from a drying oven for whole leaves and ground leaves was positively correlated with tissue C oxidation state (r = 0.63, r = 0.53, respectively) and energy content (r = 0.41, r = 0.48). Because moist fuels release less energy when burned, our observation that litter energy content is linked to moisture absorption represents a mechanism that widens the gap between comparatively flammable and non-flammable species. Also, because lignin and lipid content were each positively correlated with energy content (r > 0.66) and negatively correlated with C oxidation state (r traits in water absorption could be used to help predict shifts in ecosystem function as plant communities reassemble as result of climate change. The views expressed in this work are those of the authors and

  18. Physical properties of snacks made from cassava leaf flour

    Directory of Open Access Journals (Sweden)

    Adriana Cristina Ferrari

    2014-02-01

    Full Text Available The food industry is continually growing with new products becoming available every year. Extrusion combines a number of unit operations in one energy efficient rapid continuous process and can be used to produce a wide variety of snacks foods. The objective of this study was to evaluate the effect of extrusion temperature, screw speed, and amount of cassava leaf flour mixed with cassava starch on the physical properties of extruded snacks processed using a single screw extruder. A central composite rotational design, including three factors with 20 treatments, was used in the experimental design. Dependent variables included the expansion index, specific volume, color, water absorption index, and water solubility index. Among the parameters examined, the amount of cassava leaf flour and extrusion temperature showed significant effects on extruded snack characteristics. Mixtures containing 10% of cassava leaf flour extruded at 100°C and 255 rpm shows favorable levels of expansion, color, water absorption index, and water solubility index.

  19. BOREAS TE-10 Leaf Optical Properties

    Science.gov (United States)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Chan, Stephen S.; Middleton, Elizabeth

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-10 (Terrestrial Ecology) team collected several data sets in support of its efforts to characterize and interpret information on the reflectance, transmittance, gas exchange, oxygen evolution, and biochemical properties of boreal vegetation. This data set describes the spectral optical properties (reflectance and transmittance) of boreal forest conifers and broadleaf tree leaves as measured with a Spectron Engineering SE590 spectroradiometer at the Southern Study Area Old Black Spruce (SSA OBS), Old Jack Pine (OJP), Young Jack Pine (YJP), Old Aspen (OA), Old Aspen Auxiliary (OA-AUX), Young Aspen Auxiliary (YA-AUX), and Young Aspen (YA) sites. The data were collected during the growing seasons of 1994 and 1996 and are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  20. A comparison between leaf dielectric properties of stressed and unstressed tomato plants

    NARCIS (Netherlands)

    Van Emmerik, T.H.M.; Steele-Dunne, S.C.; Judge, J.; Van de Giesen, N.C.

    2015-01-01

    Leaf dielectric properties influence microwave scattering from a vegetation canopy. The dielectric properties of leaves are primarily a function of leaf water content. Understanding the effect of water stress on leaf dielectric properties will give insight in how plant dynamics change as a result of

  1. A comparison between leaf dielectric properties of stressed and unstressed tomato plants

    NARCIS (Netherlands)

    Van Emmerik, T.H.M.; Steele-Dunne, S.C.; Judge, J.; Van de Giesen, N.C.

    2015-01-01

    Leaf dielectric properties influence microwave scattering from a vegetation canopy. The dielectric properties of leaves are primarily a function of leaf water content. Understanding the effect of water stress on leaf dielectric properties will give insight in how plant dynamics change as a result of

  2. Antibacterial properties of biologically formed chitosan nanoparticles using aqueous leaf extract of Ocimum basilicum

    Directory of Open Access Journals (Sweden)

    Iman Rasaee

    2016-10-01

    Full Text Available Objective(s: Chitosan nanoparticles (CNPs were prepared based on the ionic gelation of chitoan with anionic compounds of Ocimum basilicum leaf extract. Materials and Methods: After addition of Ocimum basilicum leaf extract to chitosan solution, the physicochemical properties of the nanoparticles were determined by Field Emission Scanning Electron microscope (FESEM, Fourier Transform Infrared (FTIR analysis, X-ray diffraction (XRD Pattern, and Dynamic Light Scattering (DLS. The antibacterial activity of CNPs was evaluated by agar disc diffusion method. Results: The synthesized nanoparticles were found to be nearly spherical shape with size in the range of 135-729 nm. FTIR analysis revealed the presence of polyphenolic; proteins and alkaloids compounds act as effective agents for converting chitosan to CNPs. Moreover, the synthesized nanoparticles showed potent antibacterial activity against Gram positive and Gram negative bacteria. Conclusion: These results reveal that natural sources of materials such as plants could be used for preparation of CNPs instead of use of chemical substances.

  3. PROXIMATE CONTENT AND CHEMICAL COMPOSITION OF OCIMUM VIRIDIS LEAF AND OCIMUM GRATISSIUM LEAF

    Directory of Open Access Journals (Sweden)

    Abdurahman F.I.

    2012-04-01

    Full Text Available This study is aimed at determining the proximate content, concentration of some micro/macro elements and the phytochemistry of Ocimum viridis (scent leafs and Ocimum gratissimum (jaw’s mallow leafs with the view of updating its usage in orthodox and herbal medicine by man in the treatment of dysentery, diarrhea and wound healing. The leaves sampled of Ocimum viridis and Ocimum gratissimum were collected from Zannari, Jere L.G.A, Borno state, Nigeria. The proximate analysis was carried out using methods of Association of Analytical Chemist and the results showed that Ocimum viridis has higher dry matter (99.70%, crude protein (12.48%, Nitrogen free extract (2.03%, Ash (6.5% and fats (7.0%. While carbohydrate (83.40%, crude fibre (45.50% and moisture content (0.4% were estimated to be higher in Ocimum gratissimum. The levels of eight (8 elements (Ca, F, Cu, Cr, Mn, Zn, Fe, and Pb were determined using Atomic Absorption Spectrophotometry. The results revealed higher concentration in Ocimum gratissimum except for iron and manganese concentration which are higher of the elements understudy in Ocimum viridis only the lead was not detected in the samples by the methodology employed for the analysis. The concentration of anions (nitrates, phosphates and sulphates was estimated using the Smart Spectro Spectrophotometer. It shows that, Ocimum viridis has higher concentration of 11.08 mg/g and 7.04 mg/g in nitrates and sulphates respectively. And Ocimum gratissimum has higher concentration of phosphates 6.28 mg/g. The phytochemicals and some heavy and trace elements as well as a few anions were evaluated using standard procedures. The phytochemical screening of both the fresh and dry leafs revealed the presence of very high cardiac glycosides and the flavonoids, terpenoids, saponins, tannins and carbohydrates shows difference in variation of the leafs. And alkaloids were found to be absence in both fresh and dry leafs. The elemental content obtained

  4. Size-dependent changes in leaf and wood chemical traits in two Caribbean rainforest trees.

    Science.gov (United States)

    Martin, Adam R; Thomas, Sean C

    2013-12-01

    Tree functional traits and their link to patterns of growth and demography are central to informing trait-based analyses of forest communities, and mechanistic models of forest dynamics. However, few data are available on how functional traits in trees vary through ontogeny, particularly in tropical species; and less is known about how patterns of size-dependent changes in traits may differ across species of contrasting life-history strategies. Here we describe size-dependent variation in seven leaf functional traits and four wood chemical traits, in two Dominican rainforest tree species (Dacryodes excelsa Vahl. and Miconia mirabilis (Aubl.) L.O. Williams), ranging from small saplings to the largest canopy trees. With one exception, all traits showed pronounced variation with tree size (diameter at breast height, DBH). Leaf mass per area (LMA), thickness and tissue density increased monotonically with DBH in both species. Leaf area, leaf nitrogen (N) and carbon (C) : nitrogen (N) ratios also varied significantly with DBH; however, these patterns were unimodal, with peak trait values preceding the DBH at reproductive onset in both species. Size-dependent changes in leaf structural traits (LMA and leaf thickness) were generally similar in both species, while traits associated with leaf-level investment in C gain (leaf area, leaf C : N ratio) showed contrasting ontogenetic trends between species. Wood starch concentration varied with DBH in both species, also showing unimodal patterns with peaks preceding size at reproductive onset. Wood C concentration increased linearly with DBH in both species, though significantly only in M. mirabilis. Size-dependent patterns in wood chemical traits were similar between both species. Our data demonstrate pronounced variation in functional traits through tree ontogeny, probably due to a combination of environmental factors and shifts in resource allocation. Such ontogenetic variation is comparable in magnitude with interspecific

  5. Ontogenetic variation in chemical and physical characteristics of adaxial apple leaf surfaces.

    Science.gov (United States)

    Bringe, Katja; Schumacher, Christina F A; Schmitz-Eiberger, Michaela; Steiner, Ulrike; Oerke, Erich-Christian

    2006-01-01

    The reaction of plants to environmental factors often varies with developmental stage. It was hypothesized, that also the cuticle, the outer surface layer of plants is modified during ontogenesis. Apple plantlets, cv. Golden Delicious, were grown under controlled conditions avoiding biotic and abiotic stress factors. The cuticular wax surface of adaxial apple leaves was analyzed for its chemical composition as well as for its micromorphology and hydrophobicity just after unfolding of leaves ending in the seventh leaf insertion. The outer surface of apple leaves was formed by a thin amorphous layer of epicuticular waxes. Epidermal cells of young leaves exhibited a distinctive curvature of the periclinal cell walls resulting in an undulated surface of the cuticle including pronounced lamellae, with the highest density at the centre of cells. As epidermal cells expanded during ontogenesis, the upper surface showed only minor surface sculpturing and a decrease in lamellae. With increasing leaf age the hydrophobicity of adaxial leaf side decreased significantly indicated by a decrease in contact angle. Extracted from plants, the amount of apolar cuticular wax per area unit ranged from only 0.9 microgcm(-2) for the oldest studied leaf to 1.5 microgcm(-2) for the youngest studied leaf. Differences in the total amount of cuticular waxes per leaf were not significant for older leaves. For young leaves, triterpenes (ursolic acid and oleanolic acid), esters and alcohols were the main wax components. During ontogenesis, the proportion of triterpenes in total mass of apolar waxes decreased from 32% (leaf 1) to 13% (leaf 7); absolute amounts decreased by more than 50%. The proportion of wax alcohols and esters, and alkanes to a lesser degree, increased with leaf age, whereas the proportion of acids decreased. The epicuticular wax layer also contained alpha-tocopherol described for the first time to be present also in the epicuticular wax. The modifications in the chemical

  6. Foraging on individual leaves by an intracellular feeding insect is not associated with leaf biomechanical properties or leaf orientation.

    Directory of Open Access Journals (Sweden)

    Justin Fiene

    Full Text Available Nearly all herbivorous arthropods make foraging-decisions on individual leaves, yet systematic investigations of the adaptive significance and ecological factors structuring these decisions are rare with most attention given to chewing herbivores. This study investigated why an intracellular feeding herbivore, Western flower thrips (WFT Frankliniella occidentalis Pergande, generally avoids feeding on the adaxial leaf surface of cotton cotyledons. WFT showed a significant aversion to adaxial-feeding even when excised-cotyledons were turned up-side (abaxial-side 'up', suggesting that negative-phototaxis was not a primary cause of thrips foraging patterns. No-choice bioassays in which individual WFT females were confined to either the abaxial or adaxial leaf surface showed that 35% fewer offspring were produced when only adaxial feeding was allowed, which coincided with 32% less plant feeding on that surface. To test the hypothesis that leaf biomechanical properties inhibited thrips feeding on the adaxial surface, we used a penetrometer to measure two variables related to the 'toughness' of each leaf surface. Neither variable negatively co-varied with feeding. Thus, while avoiding the upper leaf surface was an adaptive foraging strategy, the proximate cause remains to be elucidated, but is likely due, in part, to certain leaf properties that inhibit feeding.

  7. Properties and Processing of the Pineapple Leaf Fiber

    Institute of Scientific and Technical Information of China (English)

    张元明; 郁崇文

    2001-01-01

    The properties and constituent of pineapple fiber were tested, and on the base of that, chemical treatment was used to improve the spinnability of the fiber, and the pure and blended yarn of pineapple fiber were produced in worsted and cotton spinning system.

  8. Silver Nanoparticles Mediated by Costus afer Leaf Extract: Synthesis, Antibacterial, Antioxidant and Electrochemical Properties.

    Science.gov (United States)

    Elemike, Elias E; Fayemi, Omolola E; Ekennia, Anthony C; Onwudiwe, Damian C; Ebenso, Eno E

    2017-04-29

    Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs). The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra-red spectrophotometer (FTIR). TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanotubes (MWCNT)-modified electrode was carried out to confirm the charge transfer properties of the nanocomposites. The comparative study showed that the CA-AgNPs/MWCNT-modified electrode demonstrated faster charge transport behaviour. The anodic current density of the electrodes in Fe(CN)₆](4-)/[Fe(CN)₆](3-) redox probe follows the order: GCE/CA-Ag/MWCNT (550 mA/cm²) > GCE/MWCNT (270 mA/cm²) > GCE (80 mA/cm²) > GCE/CA-Ag (7.93 mA/cm²). The silver nanoparticles were evaluated for their antibacterial properties against Gram negative (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa) and Gram positive (Bacillus subtilis and Staphylococcus aureus) pathogens. The nanoparticles exhibited better inhibition of the bacterial strains compared to the precursors (leaf extract of Costus afer and silver nitrate). Furthermore, the ability of the nanoparticles to scavenge DPPH radicals at different concentrations was studied using the DPPH radical scavenging assay and compared to

  9. Silver Nanoparticles Mediated by Costus afer Leaf Extract: Synthesis, Antibacterial, Antioxidant and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Elias E. Elemike

    2017-04-01

    Full Text Available Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs. The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM, transmission electron microscopy (TEM and Fourier transform infra–red spectrophotometer (FTIR. TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanotubes (MWCNT-modified electrode was carried out to confirm the charge transfer properties of the nanocomposites. The comparative study showed that the CA-AgNPs/MWCNT-modified electrode demonstrated faster charge transport behaviour. The anodic current density of the electrodes in Fe(CN6]4−/[Fe(CN6]3− redox probe follows the order: GCE/CA-Ag/MWCNT (550 mA/cm2 > GCE/MWCNT (270 mA/cm2 > GCE (80 mA/cm2 > GCE/CA-Ag (7.93 mA/cm2. The silver nanoparticles were evaluated for their antibacterial properties against Gram negative (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Gram positive (Bacillus subtilis and Staphylococcus aureus pathogens. The nanoparticles exhibited better inhibition of the bacterial strains compared to the precursors (leaf extract of Costus afer and silver nitrate. Furthermore, the ability of the nanoparticles to scavenge DPPH radicals at different concentrations was studied using the DPPH radical scavenging assay and compared to

  10. Bacterial colonization of the phyllosphere of mediterranean perennial species as influenced by leaf structural and chemical features.

    Science.gov (United States)

    Yadav, R K P; Karamanoli, K; Vokou, D

    2005-08-01

    In this study, we assessed various leaf structural and chemical features as possible predictors of the size of the phyllosphere bacterial population in the Mediterranean environment. We examined eight perennial species, naturally occurring and coexisting in the same area, in Halkidiki (northern Greece). They are Arbutus unedo, Quercus coccifera, Pistacia lentiscus, and Myrtus communis (evergreen sclerophyllous species), Lavandula stoechas and Cistus incanus (drought semi-deciduous species), and Calamintha nepeta and Melissa officinalis (non-woody perennial species). M. communis, L. stoechas, C. nepeta, and M. officinalis produce essential oil in substantial quantities. We sampled summer leaves from these species and (1) estimated the size of the bacterial population of their phyllosphere, (2) estimated the concentration of different leaf constituents, and (3) studied leaf morphological and anatomical features and expressed them in a quantitative way. The aromatic plants are on average more highly colonized than the other species, whereas the non-woody perennials are more highly colonized than the woody species. The population size of epiphytic bacteria is positively correlated with glandular and non-glandular trichome densities, and with water and phosphorus contents; it is negatively correlated with total phenolics content and the thickness of the leaf, of the mesophyll, and of the abaxial epidermis. No correlation was found with the density of stomata, the nitrogen, and the soluble sugar contents. By regression tree analysis, we found that the leaf-microbe system can be effectively described by three leaf attributes with leaf water content being the primary explanatory attribute. Leaves with water content >73% are the most highly colonized. For leaves with water content 1.34 mg g(-1) d.w.) are more colonized, and leaves with the adaxial epidermis thicker than 20.77 microm are the least colonized. Although these critical attributes and values hold true only within

  11. Effect of Biological and Chemical Pre-treatment on the Hydrolysis of Corn Leaf

    Directory of Open Access Journals (Sweden)

    Kenia Ángeles Ramírez

    2014-09-01

    Full Text Available Hydrolysis of corn leaf utilizing two treatment sequences was carried out in this study. The first treatment was chemical and involved subjecting the corn leaf to an alkaline pre-treatment and then to a smooth acid hydrolysis. The second consisted of biological delignification using the strain Trametes sp. 44 H88, followed by enzymatic hydrolysis using the enzymatic extract produced by Trichoderma sp. H88. The ligninolytic extract produced by Trametes sp. 44 H88 was used to detoxify the hydrolyzate. The results indicate that biological pre-treatment with delignification is more favorable and improves the subsequent hydrolysis, regardless of whether the hydrolysis is chemical or biological. The chemical treatment sequence obtained 80% conversion of monosaccharides, while the biological treatment sequence resulted in a 87% conversion rate. Finally, the use of the ligninolytic extract for the dephenolization of the hydrolyzate reduced the presence of compounds of phenolic origin by 23%.

  12. Accessing and using chemical property databases.

    Science.gov (United States)

    Hastings, Janna; Josephs, Zara; Steinbeck, Christoph

    2012-01-01

    Chemical compounds participate in all the processes of life. Understanding the complex interactions of small molecules such as metabolites and drugs and the biological macromolecules that consume and produce them is key to gaining a wider understanding in a systemic context. Chemical property databases collect information on the biological effects and physicochemical properties of chemical entities. Accessing and using such databases is key to understanding the chemistry of toxic molecules. In this chapter, we present methods to search, understand, download, and manipulate the wealth of information available in public chemical property databases, with particular focus on the database of Chemical Entities of Biological Interest (ChEBI).

  13. Characterization of Leaf Photosynthetic Properties for No-Tillage Rice

    Institute of Scientific and Technical Information of China (English)

    CHEN Song; XIA Guo-mian; ZHAO Wei-ming; WU Fei-bo; ZHANG Guo-ping

    2007-01-01

    A study was conducted to determine the influence of no-tillage cultivation on leaf photosynthesis of rice plants under field conditions. Experiments with the treatments, no-tillage and conventional tillage were carried out at three locations (Jiaxing, Hangzhou,and Xiaoshan, Zhejiang Province, China) for two years (2005 and 2006). Grain yield was constant in Jiaxing, but slightly higher in Hangzhou and Xiaoshan under no-tillage cultivation than that under conventional cultivation. In comparison with the conventional cultivation, no-tillage cultivation showed less biomass accumulation before heading and higher capacity of matter production during grain filling. A significantly higher leaf net photosynthetic rate was observed for the plants under no-tillage than for those under conventional tillage. The fluorescence parameter (Fv/Fm) in leaf did not show any difference between the two cultivations. The effect of cultivation management on transpiration rate (Tr) and SPAD value of rice leaf was dependent on the location and year.

  14. phytochemical properties and antibacterial activities of the leaf and ...

    African Journals Online (AJOL)

    DR. AMINU

    2Department of Medical Microbiology, Ahmadu Bello University Teaching Hospital, Zaria, NIGERIA ... World Health Organization ..... Table 2: Phytochemical characteristics of the leaf and latex extracts of Calotropis procera. Ingredient. Ethanol.

  15. Characterization of Leaf Photosynthetic Properties for No-Tillage Rice

    Directory of Open Access Journals (Sweden)

    Song CHEN

    2007-12-01

    Full Text Available A study was conducted to determine the influence of no-tillage cultivation on leaf photosynthesis of rice plants under field conditions. Experiments with the treatments, no-tillage and conventional tillage were carried out at three locations (Jiaxing, Hangzhou, and Xiaoshan, Zhejiang Province, China for two years (2005 and 2006. Grain yield was constant in Jiaxing, but slightly higher in Hangzhou and Xiaoshan under no-tillage cultivation than that under conventional cultivation. In comparison with the conventional cultivation, no-tillage cultivation showed less biomass accumulation before heading and higher capacity of matter production during grain filling. A significantly higher leaf net photosynthetic rate was observed for the plants under no-tillage than for those under conventional tillage. The fluorescence parameter (Fv/Fm in leaf did not show any difference between the two cultivations. The effect of cultivation management on transpiration rate (Tr and SPAD value of rice leaf was dependent on the location and year.

  16. Chemical composition and antibacterial activity of the essential oil the leaf of Nepeta persica

    Directory of Open Access Journals (Sweden)

    Soraya AKHSHI

    2014-11-01

    Full Text Available The essential oil from the leaf of Nepeta persica Boiss, analyzed by gas chromatography (GC and gas chromatography (GC/mass spectrometry (MS, were shown to contain 4aα, 7α, 7aβ-nepetalactone (49.46% and 4aα, 7α, 7aα-nepetalactone (14.18%. The other main constituents were n-octane (13.10%, n-decane (3.67% and germacrene-D (2.04%. Antibacterial activities of the leaf oil were evaluated using the micro-dilution broth method. Inhibitory effects on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Enterococcus faecalis were recorded. The leaf oil has difference activities against the test microorganisms. The antibacterial property of the essential oil might be ascribed to their high content of nepetalactone isomers.

  17. Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein.

    Science.gov (United States)

    Hojilla-Evangelista, Mila P; Selling, Gordon W; Hatfield, Ronald; Digman, Matthew

    2017-02-01

    Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein. Dried alfalfa leaves contained 260 g kg(-1) dry basis (DB) crude protein, with albumins being the major fraction (260 g kg(-1) of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg(-1) DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg(-1) soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m(2)  g(-1) protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0. It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Chemical constituents and antihistamine activity of Bixa orellana leaf extract

    Directory of Open Access Journals (Sweden)

    Yong Yoke Keong

    2013-02-01

    Full Text Available Abstract Background Bixa orellana L. has been traditionally used in Central and South America to treat a number of ailments, including internal inflammation, and in other tropical countries like Malaysia as treatment for gastric ulcers and stomach discomfort. The current study aimed to determine the major chemical constituents of the aqueous extract of B. orellana (AEBO and to evaluate the antihistamine activity of AEBO during acute inflammation induced in rats. Methods Acute inflammation was produced by subplantar injection of 0.1 mL of 0.1% histamine into the right hind paw of each rat in the control and treatment groups. The degree of edema was measured before injection and at the time points of 30, 60, 120, 180, 240 and 300 min after injection. Changes of peritoneal vascular permeability were studied using Evans blue dye as a detector. Vascular permeability was evaluated by the amount of dye leakage into the peritoneal cavity in rats. To evaluate the inhibitory effect of AEBO on biochemical mediators of vascular permeability, the levels of nitric oxide (NO and vascular endothelial growth factor (VEGF were determined in histamine-treated paw tissues. The major constituents of AEBO were determined by gas chromatography–mass spectrometry (GC-MS analysis. Results AEBO produced a significant inhibition of histamine-induced paw edema starting at 60 min time point, with maximal percentage of inhibition (60.25% achieved with a dose of 150 mg/kg of AEBO at 60 min time point. Up to 99% of increased peritoneal vascular permeability produced by histamine was successfully suppressed by AEBO. The expression of biochemical mediators of vascular permeability, NO and VEGF, was also found to be downregulated in the AEBO treated group. Gas chromatography–mass spectrometry (GC-MS analysis revealed that the major constituent in AEBO was acetic acid. Conclusions The experimental findings demonstrated that the anti-inflammatory activity of AEBO was

  19. Chemical composition of Melicope belahe (Baill.) T. G. Hartley (Rutaceae) leaf essential oil from Madagascar.

    Science.gov (United States)

    Rabehaja, Delphin J R; Garcia, Gabriel; Charmillon, Julie-Marie; Désiré, Odile; Paoli, Mathieu; Ramanoelina, Panja A R; Tomi, Félix

    2017-01-01

    Melicope belahe (Baill.) T.G. Hartley (Rutaceae) is an endemic species to Madagascar. The chemical composition of leaf essential oil is reported for the first time. A sample was extracted by hydrodistillation and analysis was carried out by combination of chromatographic (GC), spectroscopic and spectrometric (MS, (13)C NMR) techniques. In total, 56 compounds have been identified. The chemical composition was dominated by α-pinene (42.6%) followed by linalool (6.2%) and (E)-β-caryophyllene (5.2%).

  20. Chemical composition and antimicrobial activity of hexane leaf extract of Anisopus mannii (Asclepiadaceae

    Directory of Open Access Journals (Sweden)

    Aliyu Muhammad Musa

    2015-06-01

    Full Text Available Objective: To determine the chemical constituents and antimicrobial activity of the hexane leaf extract of Anisopus mannii against a wide range of human pathogenic microorganisms. Methods: The chemical constituents of the hexane leaf extract was determined using gas chromatography-mass spectrometry (GC-MS analysis; and the antimicrobial activity was evaluated on clinical susceptible and resistant bacterial and fungal isolates using the disc diffusion and broth micro dilution methods. Results: GC-MS analysis of the hexane leaf extract revealed 32 compounds, representing 73.8% of the identified components. The major compounds were hexadecanoic acid, ethyl ester (34%, oxirane, hexadecyl- (11% and 9, 12, 15-octadecatrienoic acid, ethyl ester, (Z, Z, Z (9.6%. Results from the antimicrobial activity demonstrated higher inhibition zones against B. cereus (29 mm, followed by S. pyogenes (28 mm. Other notable inhibitions were observed with E. faecalis (27 mm, P. vulgaris (26 mm and MRSA (25 mm. The MIC values ranged from 0.625 mg/mL to 1.25 mg/mL while the MBC/MFC values ranged from 2.5 mg/mL to 5.0 mg/mL. Conclusion: These results support the traditional use of the plant and demonstrate the huge potential of A. mannii as a source of antimicrobial compounds. [J Intercult Ethnopharmacol 2015; 4(2.000: 129-133

  1. Physico-chemical characterization of banana varieties resistant to black leaf streak disease for industrial purposes

    Directory of Open Access Journals (Sweden)

    Rossana Catie Bueno de Godoy

    2016-01-01

    Full Text Available ABSTRACT: Cultivated bananas have very low genetic diversity making them vulnerable to diseases such as black-Sigatoka leaf spot. However, the decision to adopt a new banana variety needs to be based on a robust evaluation of agronomical and physical-chemical characteristics. Here, we characterize new banana varieties resistant to black-Sigatoka leaf spot and compare them to the most widely used traditional variety (Grand Naine. Each variety was evaluated for a range of physic-chemical attributes associated with industrial processing and flavor: pH, TTA, TSS/TTA, total sugars, reducing sugars and non-reducing sugars, humidity, total solids and yield. The Thap Maeo variety had the highest potential as a substitute for the Grand Naine variety, having higher levels of total soluble solids, reducing sugars, total sugars and humidity. The Caipira and FHIA 2 varieties also performed well in comparison with the Grand Naine variety. Cluster analysis indicated that the Grand Naine variety was closely associated with varieties from the Gross Michel subgroup (Bucaneiro, Ambrosia and Calipso and the Caipira variety, all of which come from the same AAA genomic group. It was concluded that several of the new resistant varieties could potentially substitute the traditional variety in areas affected by black-Sigatoka leaf spot disease.

  2. In Vitro Antioxidant Properties of Methanolic Leaf Extract of Vernonia ...

    African Journals Online (AJOL)

    olayemitoyin

    implicated in many pathological diseases (Lobo et al.,. 2010; Aprioku, 2013 ... then suggested that successful antioxidant treatment should be ... green vegetable or spice in the popular bitter-leaf soup. ..... to cancer: Functional role of fermented papaya preparation as .... cellular anti-oxidant activities of an aqueous extract of ...

  3. Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sung Ha [Maxoft Inc., Seongnam (Korea, Republic of); Choi, Bok Lok [Gangneung-Wonju National University, Gangneung (Korea, Republic of)

    2014-12-15

    This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses.

  4. The worldwide leaf economics spectrum

    NARCIS (Netherlands)

    Wright, I.J.; Reich, P.B.; Westoby, M.; Ackerly, D.D.; Baruch, Z.; Bongers, F.J.J.M.; Cavender-Bares, J.; Chapin, T.; Cornelissen, J.H.C.; Diemer, M.; Flexas, J.; Garnier, E.; Groom, P.K.; Gulias, J.; Hikosaka, K.; Lamont, B.B.; Lee, T.; Lee, W.; Lusk, C.; Midgley, J.J.; Navas, M.L.; Niinements, Ü.; Oleksyn, J.; Osada, N.; Poorter, H.; Poot, P.; Prior, L.; Pyankov, V.I.; Roumet, C.; Thomas, S.C.; Tjoelker, M.G.; Veneklaas, E.J.; Villar, R.

    2004-01-01

    Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients

  5. Mechanical properties of pineapple leaf fibre reinforced polypropylene composites

    Energy Technology Data Exchange (ETDEWEB)

    Arib, R.M.N. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sapuan, S.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)]. E-mail: sapuan@eng.upm.edu.my; Ahmad, M.M.H.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Paridah, M.T. [Faculty of Forestry, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Zaman, H.M.D. Khairul [Radiation Processing Technology Division, Malaysian Institute for Nuclear Technology Research (MINT), Bangi 43000 Kajang, Selangor (Malaysia)

    2006-07-01

    Pineapple leaf fibre, which is rich in cellulose, relative inexpensive and abundantly available has the potential for polymer-reinforced composite. The present study investigates the tensile and flexural behaviours of pineapple leaf fibre-polypropylene composites as a function of volume fraction. The tensile modulus and tensile strength of the composites were found to be increasing with fibre content in accordance with the rule of mixtures. The tensile modulus and tensile strength with a volume fraction 10.8% are 687.02 and 37.28 MPa, respectively. The flexural modulus gives higher value at 2.7% volume fraction. The flexural strength of the composites containing 5.4% volume fraction was found to be higher than that of pure polypropylene resin by 5.1%. Scanning electron microscopic studies were carried out to understand the fibre-matrix adhesion and fibre breakage.

  6. Evolutionary Position and Leaf Toughness Control Chemical Transformation of Litter, and Drought Reinforces This Control: Evidence from a Common Garden Experiment across 48 Species

    OpenAIRE

    Xu Pan; Yao-Bin Song; Can Jiang; Guo-Fang Liu; Xue-Hua Ye; Xiu-Fang Xie; Yu-Kun Hu; Wei-Wei Zhao; Lijuan Cui; Johannes H. C. Cornelissen; Ming Dong; Andreas Prinzing

    2015-01-01

    Plant leaf litter is an important source of soil chemicals that are essential for the ecosystem and changes in leaf litter chemical traits during decomposition will determine the availability of multiple chemical elements recycling in the ecosystem. However, it is unclear whether the changes in litter chemical traits during decomposition and their similarities across species can be predicted, respectively, using other leaf traits or using the phylogenetic relatedness of the litter species. He...

  7. Chemical and catalytic properties of elemental carbon

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.G.; Brodzinsky, R.; Gundel, L.A.; Novakov, T.

    1980-10-01

    Elemental carbon particles resulting from incomplete combustion of fossil fuel are one of the major constituents of airborne particulate matter. These particles are a chemically and catalytically active material and can be an effective carrier for other toxic air pollutants through their adsorptive capability. The chemical, adsorptive, and catalytic behaviors of carbon particles depend very much on their crystalline structure, surface composition, and electronic properties. This paper discusses these properties and examines their relevance to atmospheric chemistry.

  8. Chemical Composition and Water Permeability of Fruit and Leaf Cuticles of Olea europaea L.

    Science.gov (United States)

    Huang, Hua; Burghardt, Markus; Schuster, Ann-Christin; Leide, Jana; Lara, Isabel; Riederer, Markus

    2017-10-03

    The plant cuticle, protecting against uncontrolled water loss, covers olive (Olea europaea) fruits and leaves. The present study describes the organ-specific chemical composition of the cuticular waxes and the cutin and compares three developmental stages of fruits (green, turning, and black) with the leaf surface. Numerous organ-specific differences, such as the total coverage of cutin monomeric components (1034.4 μg cm(-2) and 630.5 μg cm(-2)) and the cuticular waxes (201.6 μg cm(-2) and 320.4 μg cm(-2)) among all three fruit stages and leaves, respectively, were detected. Water permeability as the main cuticular function was 5-fold lower in adaxial leaf cuticles (2.1 × 10(-5) m s(-1)) in comparison to all three fruit stages (9.5 × 10(-5) m s(-1)). The three fruit developmental stages have the same cuticular water permeability. It is hypothesized that a higher weighted average chain length of the acyclic cuticular components leads to a considerably lower permeability of the leaf as compared to the fruit cuticle.

  9. Chemical composition and anti-proliferative and anti-inflammatory effects of the leaf and whole-plant samples of diploid and tetraploid Gynostemma pentaphyllum (Thunb.) Makino.

    Science.gov (United States)

    Xie, Zhuohong; Huang, Haiqiu; Zhao, Yang; Shi, Haiming; Wang, Shaoke; Wang, Thomas T Y; Chen, Pei; Yu, Liangli Lucy

    2012-05-01

    Leaf and whole-plant samples of the diploid and tetraploid Gynostemma pentaphyllum (GP) were investigated and compared for their chemical compositions, and their potential anti-proliferative and anti-inflammatory effects. The highest levels of total flavonoids and phenolics were observed in the diploid leaf botanical (2L3) at 36.84mg rutin equiv/g and 41.15mg gallic acid equiv/g, respectively. The diploid leaf sample (2L2) had the highest amount of rutin and quercetin contents of 77.7μmol quercetin equiv/g. The tetraploid whole-plant botanical (4L3) had the highest total saponin content of 227.1mg gypenoside equiv/g. Extracts from all tested GP samples showed time- and dose-dependent antiproliferative effects in HT-29 cells, and the diploid leaf samples had the overall highest inhibitory activity. These extracts had different order of antiproliferative properties in the LNCaP cells, suggesting the potential selective inhibition of GP extracts against different types of cancer cells and the effect of the cell model in screening and evaluation of antiproliferative components. In addition, the diploid leaf extracts showed the strongest inhibitory effects on the expression of TNF-α, IL-6 and COX-2 mRNA at final concentrations of 0.2 and 1mg botanical equiv/ml media. The results from this study will be used to develop new nutraceutical products from G. pentaphyllum.

  10. Structure-Property Characterization of the Crinkle-Leaf Peach Wood Phenotype: A Future Model System for Wood Properties Research?

    Science.gov (United States)

    Wiedenhoeft, Alex C.; Arévalo, Rafael; Ledbetter, Craig; Jakes, Joseph E.

    2016-09-01

    Nearly 400 million years of evolution and field-testing by the natural world has given humans thousands of wood types, each with unique structure-property relationships to study, exploit, and ideally, to manipulate, but the slow growth of trees makes them a recalcitrant experimental system. Variations in wood features of two genotypes of peach ( Prunus persica L.) trees, wild-type and crinkle-leaf, were examined to elucidate the nature of weak wood in crinkle-leaf trees. Crinkle-leaf is a naturally-occurring mutation in which wood strength is altered in conjunction with an easily observed `crinkling' of the leaves' surface. Trees from three vigor classes (low growth rate, average growth rate, and high growth rate) of each genotype were sampled. No meaningful tendency of dissimilarities among the different vigor classes was found, nor any pattern in features in a genotype-by-vigor analysis. Wild-type trees exhibited longer vessels and fibers, wider rays, and slightly higher specific gravity. Neither cell wall mechanical properties measured with nanoindentation nor cell wall histochemical properties were statistically or observably different between crinkle-leaf and wild-type wood. The crinkle-leaf mutant has the potential to be a useful model system for wood properties investigation and manipulation if it can serve as a field-observable vegetative marker for altered wood properties.

  11. Aloe vera phenomenon: a review of the properties and modern uses of the leaf parenchyma gel

    Energy Technology Data Exchange (ETDEWEB)

    Grindlay, D.; Reynolds, T.

    1986-06-01

    The mucilaginous gel from the parenchymatous cells in the leaf pulp of Aloe vera has been used since early times for a host of curative purposes. This gel should be distinguished clearly from the bitter yellow exudate originating from the bundle sheath cells, which is used for its purgative effects. Aloe vera gel has come to play a prominent role as a contemporary folk remedy, and numerous optimistic, and in some cases extravagant, claims have been made for its medicinal properties. Modern clinical use of the gel began in the 1930s, with reports of successful treatment of X-ray and radium burns, which led to further experimental studies using laboratory animals in the following decades. The reports of these experiments and the numerous favourable case histories did not give conclusive evidence, since although positive results were usually described, much of the work suffered from poor experimental design and insufficiently large test samples. In addition some conflicting or inconsistent results were obtained. With the recent resurgence of interest in Aloe vera gel, however, new experimental work has indicated the possibility of distinct physiological effects. Chemical analysis has shown the gel to contain various carbohydrate polymers, notably either glucomannans or pectic acid, along with a range of other organic and inorganic components. Although many physiological properties of the gel have been described, there is no certain correlation between these and the identified gel components. 154 references.

  12. 菠萝茎叶还田对土壤理化特性及下茬菠萝生长的调控效应%Effects of Stem-leaf Returning on Physic-chemical Properties of Soil and Growth Performances of Next-cropping Pineapples

    Institute of Scientific and Technical Information of China (English)

    刘传和; 刘岩; 凡超; 匡石滋; 田世尧

    2012-01-01

    在大田条件下研究菠萝茎叶粉碎后直接还田(简称茎叶还田)对土壤理化特性以及下茬菠萝植株生长等的影响.结果表明,茎叶还田后土壤容重显著降低;土壤有机质、有效P、速效K含量等较对照有不同程度的提高,但土壤有效N含量降低.土壤中的脲酶、过氧化氢酶、酸性磷酸酶以及转化酶活性增强,其中酸性磷酸酶和转化酶显著提高.菠萝茎叶还田后土壤中的细菌、放线菌数量增多,真菌数量减少.菠萝茎叶还田促进了下茬菠萝植株生长,株高、叶长、叶宽、青叶数、根条数、根长以及地上部和地下部鲜质量等指标都高于对照.茎叶还田提高了下茬菠萝叶片的叶绿素、可溶性糖及可溶性蛋白含量,植株根系活力增强.茎叶还田后菠萝果实纵、横径增加,单果重、产量提高.%A field experiment was conducted to investigate the influence of shattered stem-leaf returning directly (RD) on the physic-chemical properties of soil and the growth performances of next-cropping pineapples. The obtained results indicated that bulk density of soil was decreased by RD treatment. Contents of organic matter, available P and available K of soil were increased in some degree when compared with the control. The activities of urease, catalase, acid phosphatase and invertase of soil were strengthened. In particular, significant difference was observed in acid phosphatase and invertase when compared with the control. RD treatment increased the population of bacteria and actinomycetes in soil. But the population of fungi was decreased when compared with the control. RD promoted the growth of next-cropping pineapple plants. The growth characteristics such as plant height, leaf length, number of green leaves, number of roots, and root length as well as the weight of aboveground and underground were higher than those of the control. The contents of chlorophyll a and chlorophyll b were increased. The contents

  13. Chemical warfare: Leaf-cutting ants defend themselves and their gardens against parasite attack by deploying antibiotic secreting bacteria.

    Science.gov (United States)

    Samuels, Richard Ian; Mattoso, Thalles Cardoso; Moreira, Denise D O

    2013-03-01

    Leaf-cutting ants are well known for their highly complex social organization, which provides them with a strong defense against parasites invading their colonies. Besides this attribute, these insects have morphological, physiological and structural characteristics further reinforcing the defense of their colonies. With the discovery of symbiotic bacteria present on the integument of leaf-cutting ants, a new line of defense was proposed and considered to be specific for the control of a specialized fungal parasite of the ants' fungus gardens (Escovopsis). However, recent studies have questioned the specificity of the integumental bacteria, as they were also found to inhibit a range of fungi, including entomopathogens. The microbiota associated with the leaf-cutting ant gardens has also been proposed as another level of chemical defense, protecting the garden from parasite invasion. Here we review the chemical defense weaponry deployed by leaf-cutting ants against parasites of their fungus gardens and of the ants themselves.

  14. Timing of leaf removal modifies chemical and phenolic composition of Sauvignon Blanc wine

    Directory of Open Access Journals (Sweden)

    Wurz Douglas André

    2017-01-01

    Full Text Available The objective of this work was to evaluate the effect of different defoliation times on the chemical and phenolic composition of Sauvignon Blanc wine in high altitude regions of Santa Catarina - Brazil. The experiment was conducted in the 2015 and 2016 seasons, in a vineyard located in the city of São Joaquim – Santa Catarina State. The defoliation was carried out during phenological stages: full bloom, berries pepper-corn size, pea-sized berries, veraison, 15 days after veraison and control without leaf removal. During harvest, severity of Botrytis cinerea was assessed by visual evaluation through a diagrammatic scale. For the wine samples from each season, total acidity (meq L−1, pH, total polyphenol content (mg L−1 of gallic acid and color (Abs 420nm were performed. For the wines of the 2015 harvest, phenolic compounds were analyzed: gallic acid, catechin, vanillic acid, P-coumaric acid and rutin. The chemical composition of Sauvignon Blanc wine was affected as a result of leaf removal timing, defoliation carried out in full bloom, berries pepper-corn size and pea-sized berries reduced total acidity and increased pH of the wines in both seasons. For wine color, in both seasons, it was found a greater yellow coloration in wines originated from grapes where the plants were not defoliated. The increase of yellow coloration is due to the oxidation of catechins and epicatechins, which is related to the increase of botrytis bunch rot. In the 2015 season there were no influence of leaf removal timing in total polyphenols, however, in the 2016, the defoliation performed in full bloom resulted in lower polyphenols contents. Wines from non-defoliated plants presented higher values of catechin, rutin, P-coumaric acid and gallic acid, related to yellow coloration of wines and greater susceptibility to darkening and oxidation. For vanillic acid, wines from non-defoliated plants have the lowest values, this compound is important in wine preservation

  15. Minimizing measurement uncertainties of coniferous needle-leaf optical properties, part I: methodological review

    NARCIS (Netherlands)

    Yanez Rausell, L.; Schaepman, M.E.; Clevers, J.G.P.W.; Malenovsky, Z.

    2014-01-01

    Optical properties (OPs) of non-flat narrow plant leaves, i.e., coniferous needles, are extensively used by the remote sensing community, in particular for calibration and validation of radiative transfer models at leaf and canopy level. Optical measurements of such small living elements are, howeve

  16. Minimizing measurement uncertainties of coniferous needle-leaf optical properties, part I: methodological review

    NARCIS (Netherlands)

    Yanez Rausell, L.; Schaepman, M.E.; Clevers, J.G.P.W.; Malenovsky, Z.

    2014-01-01

    Optical properties (OPs) of non-flat narrow plant leaves, i.e., coniferous needles, are extensively used by the remote sensing community, in particular for calibration and validation of radiative transfer models at leaf and canopy level. Optical measurements of such small living elements are, howeve

  17. Beyond leaf color: Comparing camera-based phenological metrics with leaf biochemical, biophysical, and spectral properties throughout the growing season of a temperate deciduous forest

    Science.gov (United States)

    Yang, Xi; Tang, Jianwu; Mustard, John F.

    2014-03-01

    Plant phenology, a sensitive indicator of climate change, influences vegetation-atmosphere interactions by changing the carbon and water cycles from local to global scales. Camera-based phenological observations of the color changes of the vegetation canopy throughout the growing season have become popular in recent years. However, the linkages between camera phenological metrics and leaf biochemical, biophysical, and spectral properties are elusive. We measured key leaf properties including chlorophyll concentration and leaf reflectance on a weekly basis from June to November 2011 in a white oak forest on the island of Martha's Vineyard, Massachusetts, USA. Concurrently, we used a digital camera to automatically acquire daily pictures of the tree canopies. We found that there was a mismatch between the camera-based phenological metric for the canopy greenness (green chromatic coordinate, gcc) and the total chlorophyll and carotenoids concentration and leaf mass per area during late spring/early summer. The seasonal peak of gcc is approximately 20 days earlier than the peak of the total chlorophyll concentration. During the fall, both canopy and leaf redness were significantly correlated with the vegetation index for anthocyanin concentration, opening a new window to quantify vegetation senescence remotely. Satellite- and camera-based vegetation indices agreed well, suggesting that camera-based observations can be used as the ground validation for satellites. Using the high-temporal resolution dataset of leaf biochemical, biophysical, and spectral properties, our results show the strengths and potential uncertainties to use canopy color as the proxy of ecosystem functioning.

  18. Chemical variability of Cleistopholis patens (Benth.) Engl. et Diels leaf oil from ivory coast.

    Science.gov (United States)

    Ouattara, Zana Adama; Boti, Jean Brice; Attioua, Koffi Barthelemy; Ahibo, Antoine Coffy; Casanova, Joseph; Tomi, Félix; Bighelli, Ange

    2013-11-01

    The chemical composition of 48 leaf oil samples isolated from individual plants of Cleistopholis patens (Benth.) Engl. et Diels harvested in four Ivoirian forests was investigated by GC-FID (determination of retention indices), GC/MS, and (13) C-NMR analyses. The main components identified were β-pinene (traces-59.1%), sabinene (traces-54.2%), (E)-β-caryophyllene (0.3-39.3%), linalool (0.1-38.5%), (E)-β-ocimene (0.1-33.2%), germacrene D (0.0-33.1%), α-pinene (0.1-32.3%), and germacrene B (0-21.2%). The 48 oil compositions were submitted to hierarchical clustering and principal components analyses, which allowed the distinction of three groups within the oil samples. The oil composition of the major group (GroupI, 33 samples) was dominated by (E)-β-caryophyllene and linalool. The oils of Group II (eight samples) contained mainly β-pinene and α-pinene, while those of Group III (seven samples) were dominated by sabinene, limonene, and β-phellandrene. Moreover, the compositions of the Ivoirian C. patens leaf oils differed from those of Nigerian and Cameroonian origins. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  19. Influence of environmental pollution on leaf properties of urban plane trees, Platanus orientalis L.

    Science.gov (United States)

    Pourkhabbaz, Alireza; Rastin, Nayerah; Olbrich, Andrea; Langenfeld-Heyser, Rosemarie; Polle, Andrea

    2010-09-01

    To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily loaded by dust particles but the stomata were not occluded; the cuticle was thinner; other anatomical properties were unaffected suggesting that plane trees can cope with traffic exhaust in megacities.

  20. Influence of Environmental Pollution on Leaf Properties of Urban Plane Trees, Platanus orientalis L.

    Science.gov (United States)

    Pourkhabbaz, Alireza; Rastin, Nayerah; Olbrich, Andrea; Langenfeld-Heyser, Rosemarie

    2010-01-01

    To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily loaded by dust particles but the stomata were not occluded; the cuticle was thinner; other anatomical properties were unaffected suggesting that plane trees can cope with traffic exhaust in megacities. PMID:20577871

  1. A lucrative chemical processing of bamboo leaf biomass to synthesize biocompatible amorphous silica nanoparticles of biomedical importance

    Science.gov (United States)

    Rangaraj, Suriyaprabha; Venkatachalam, Rajendran

    2017-06-01

    Synthesis of silica nanoparticles from natural resources/waste via cost effective route is presently one of the anticipating strategies for extensive applications. This study reports the low-cost indigenous production of silica nanoparticles from the leftover of bamboo (leaf biomass) through thermal combustion and alkaline extraction, and examination of physico-chemical properties and yield percentage using comprehensive characterization tools. The outcome of primed silica powder exhibits amorphous particles (average size: 25 nm) with high surface area (428 m2 g-1) and spherical morphology. Despite the yield percentage of silica nanoparticles from bamboo leave ash is 50.2%, which is less than rice husk ask resources (62.1%), the bamboo waste is only an inexpensive resource yielding high purity (99%). Synthesis of silica nanoparticles from natural resources/waste with the help of lucrative route is at present times one of the anticipating strategies for extensive applications. In vitro study on animal cell lines (MG-63) shows non-toxic nature of silica nanoparticles up to 125 µg mL-1. Hence, this study highlights the feasibility for the mass production of silica nanoparticles from bamboo leave waste rather using chemical precursor of silica for drug delivery and other medical applications.

  2. Study of Tensile Properties and Deflection Temperature of Polypropylene/Subang Pineapple Leaf Fiber Composites

    Science.gov (United States)

    Hafizhah, R.; Juwono, A. L.; Roseno, S.

    2017-05-01

    The development of eco-friendly composites has been increasing in the past four decades because the requirement of eco-friendly materials has been increasing. Indonesia has a lot of natural fiber resources and, pineapple leaf fiber is one of those fibers. This study aimed to determine the influence of weight fraction of pineapple leaf fibers, that were grown at Subang, to the tensile properties and the deflection temperature of polypropylene/Subang pineapple leaf fiber composites. Pineapple leaf fibers were pretreated by alkalization, while polypropylene pellets, as the matrix, were extruded into sheets. Hot press method was used to fabricate the composites. The results of the tensile test and Heat Deflection Temperature (HDT) test showed that the composites that contained of 30 wt.% pineapple leaf fiber was the best composite. The values of tensile strength, modulus of elasticity and deflection temperature were (64.04 ± 3.91) MPa; (3.98 ± 0.55) GPa and (156.05 ± 1.77) °C respectively, in which increased 187.36%, 198.60%, 264.72% respectively from the pristine polypropylene. The results of the observation on the fracture surfaces showed that the failure modes were fiber breakage and matrix failure.

  3. Effect of Spent Mushroom Substrate on Physical and Chemical Properties and Enzymic Activity of Rice

    Institute of Scientific and Technical Information of China (English)

    Hairu YU; Xue LI; Xin ZHANG; Changming GE; Renzhe PIAO; Meishan LI; Zongjun CUI; Hongyan ZHAO

    2016-01-01

    In order to explore the substitution substrate for rice seedling on upland fields,this paper uses spent mushroom substrate to study the physical and chemical properties of substrate,enzymic activity and number of tillers during the cultivation of rice seedling on upland fields.The results show that at the three stages of rice seedling cultivation( two-leaf stage,three-leaf stage,four-leaf stage),the content of organic matter and EC in spent mushroom substrate is higher than in the control soil,p H is within the range suitable for the growth of rice,and other nutrients( total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus) are slightly different in different periods;except phosphatase,there are significant differences in urease,catalase and sucrase between spent mushroom substrate and the control soil; the number of tillers under spent mushroom substrate is larger than under the control.

  4. Chemical Composition and Antimicrobial Activity of the Essential Oils from the Flower, Leaf, and Stem of Senecio pandurifolius

    Directory of Open Access Journals (Sweden)

    Gonca Tosun

    2011-01-01

    Full Text Available The essential oils from the fresh flower, leaf, and stem of Senecio pandurifolius (Asteraceae were isolated by hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. A total of forty-five, sixty, and forty-two compounds were identified, constituting over 90.1 %, 88.0%, and 89.0% of oil composition of the flower, leaf, and stem of S. pandurifolius , respectively. The chemical profile reveals the dominance of sesquiterpene hydrocarbons (flower: 42.4%, leaf: 43.4%, stem: 52.3% . The main components of essential oils own to S. pandurifolius were α- cuprenene (30.7% in flower, α­- zingiberene (16.1% in leaf and γ -curcumene (14.9% in stem. Terpene related compounds were in minor amounts in all parts (flower: 1.4%, leaf: 1.5%, stem: 1.9% of the S. pandurifolius . Also there was no monoterpene hydrocarbons and oxygenated monoterpenes in the essential oil of the stem. In addition, antimicrobial activities of the essential oils of S. pandurifolius were investigated. The oils showed activity against Gram positive bacteria, mycobacterium and fungi, but not Gram negative bacteria. A high antimycobacterial activity was observed with leaf essential oil, which deserves further investigation to determine its active components.

  5. Biomass Allocation and Leaf Chemical Defence in Defoliated Seedlings of Quercus serrata with Respect to Carbon–Nitrogen Balance

    OpenAIRE

    Hikosaka, Kouki; TAKASHIMA, TERUYUKI; Kabeya, Daisuke; HIROSE, TADAKI; Kamata, Naoto

    2005-01-01

    • Background and Aims Both nutrient availability and defoliation affect the carbon–nutrient balance in plants, which in turn influences biomass allocation (e.g. shoot-to-root ratio) and leaf chemical composition (concentration of nitrogen and secondary compounds). In this study it is questioned whether defoliation alters biomass allocation and chemical defence in a similar fashion to the response to nutrient deficiency.

  6. Sound Absorption and Friction Properties of Nano-Lotus Leaf Coated Concrete for Rigid Pavement

    Directory of Open Access Journals (Sweden)

    Marcelo GONZALEZ

    2016-09-01

    Full Text Available This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, particularly during heavy rainfall.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7638

  7. Changes in leaf optical properties associated with light-dependent chloroplast movements.

    Science.gov (United States)

    Davis, Phillip A; Caylor, Steven; Whippo, Craig W; Hangarter, Roger P

    2011-12-01

    We surveyed 24 plant species to examine how leaf anatomy influenced chloroplast movement and how the optical properties of leaves change with chloroplast position. All species examined exhibited light-dependent chloroplast movements but the associated changes in leaf absorptance varied considerably in magnitude. Chloroplast movement-dependent changes in leaf absorptance were greatest in shade species, in which absorptance changes of >10% were observed between high- and low-light treatments. Using the Kubelka-Munk theory, we found that changes in the absorption (k) and chlorophyll a absorption efficiency (k*) associated with chloroplast movement correlated with cell diameter, such that the narrower, more columnar cells found in sun leaves restricted the ability of chloroplasts to move. The broader, more spherical cells of shade leaves allowed greater chloroplast rearrangements and in low-light conditions allowed efficient light capture. Across the species tested, light-dependent chloroplast movements modulated leaf optical properties and light absorption efficiency by manipulating the package (sieve or flattening) effect but not the detour (path lengthening) effect.

  8. Sound Absorption and Friction Properties of Nano-Lotus Leaf Coated Concrete for Rigid Pavement

    Directory of Open Access Journals (Sweden)

    Marcelo GONZALEZ

    2016-09-01

    Full Text Available This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, particularly during heavy rainfall.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7638

  9. Modulation of Leaf Economic Traits and Rates by Soil Properties, at Global Scale

    Science.gov (United States)

    Maire, V.; Wright, I. J.; Reich, P. B.; Batjes, N. H., Jr.; van Bodegom, P. M.; Bhaskar, R.; Santiago, L. S.; Ellsworth, D.; Niinemets, U.; Cornwell, W.

    2014-12-01

    Photosynthesis can be construed as an economic process that optimises the costs of acquisition, transport and utilisation of two substitutable photosynthetic resources: water and nitrogen. The influence of soil fertility on photosynthetic rates and leaf 'economic' traits related with H2O and N costs is poorly quantified in higher plants in comparison with the effects of climate. We set out to address this situation by quantifying the unique and shared contributions to global leaf-trait variation from soils and climate. Using a trait dataset comprising 1509 species from 288 sites, with climate and soil data derived from global datasets, we quantified the effects of soil and climate properties on photosynthetic traits: light-saturated photosynthetic rate (Aarea), stomatal conductance to water vapour (gs), leaf N and P (Narea and Parea) and specific leaf area (SLA). We used mixed regression models, multivariate analyses and variance partitioning. Along a first dimension of soil fertility, soil pH covaried positively with measures of base status and climatic aridity, and negatively with soil organic C content. Along this dimension from low to high soil pH, Narea, Parea and Aarea increased and SLA decreased. Along an independent dimension of soil fertility, gs declined and Parea increased with soil available P (Pavail). Overall, soil variables were stronger predictors of leaf traits than were climate variables, except for SLA. Importantly, soils and climate were not redundant information to explain leaf trait variation but were not additive either. Shared effects of soil and climate dominated over their independent effects on Narea and Parea, while unique effects of soils dominated for Aarea and gs. Three environmental variables were key for explaining variation in leaf traits: soil pH and Pavail, and climatic aridity. Although the reliability of global soils datasets lags behind that of climate datasets our results nonetheless provide compelling evidence that both can

  10. Chemical composition of leaf extracts of Stevia rebaudiana Bertoni grown experimentally in Vojvodina

    Directory of Open Access Journals (Sweden)

    IVANA S. MARKOVIC

    2008-03-01

    Full Text Available The chemical composition of leaf extracts of Stevia rebaudiana Bertoni, grown for the first time on an experimental field near Zrenjanin, was examined by GC–MS. The tested plant material was harvested in September of 2002. To analyze the chemical composition of the lipophilic components of the plant leaves, essential oils and ethyl acetate extract were isolated. Qualitative analysis of the essential oil obtained by hydrodistillation showed that among the identified 88 compounds, the majority were mono- and sesquiterpenes (50 types identified. By analysing the ethyl acetate extract, the presence of fatty acids (present as free and as esters, n-alkanes, n-alkenes, cyclic alkanes, alcohols, aldehydes, ketones, etc. was ascertained. Sesquiterpenes prevailed among the terpenes (50 types identified. Further constituents identified in ethyl acetate extract included sterols. Nerol, b-cyclocitral, safranal, aromadendrene, a-amorphene and T-muurolol were identified for the first time in this species, with match values over 90 %. Taking into consideration that these terpenes were identified for the first time in this species, it is obvious that Stevia rebaudiana grown in this area possesses certain specific characteristics that can be ascribed to cultivation on a domestic plantation.

  11. Chemical Composition and Antimicrobial Activity of Leaf, Ripe and Unripe Peel of Bitter Orange (Citrus aurantium Essential Oils

    Directory of Open Access Journals (Sweden)

    Fatemeh Azhdarzadeh

    2016-02-01

    Full Text Available Background and Objectives: The chemical composition and antimicrobial activity of bitter orange (Citrus aurantium leaf, ripe and unripe peel essential oils, cultivated in southwest of Iran, were investigated. Materials and Methods: The analysis of chemical composition of hydro-distilled essential oils was carried out by GC-MS. The disc diffusion and broth micro-dilution were used to assay the antimicrobial effect of achieved essential oils. Results: According to the GC-MS analysis, 34, 39 and 21 components were determined in the leaf, ripe and unripe peel, respectively. The results revealed that the main components of all essential oils were linalool and limonene. The oxygenated monoterpene and hydrocarbonated monoterpene were the main chemical groups of leaf and peel essential oils, respectively. Although all of the examined essential oils had antimicrobial potential, the leaf and unripe peel essential oils with MIC of 4.67 mg/ml were the most effective against the bacteria and yeast species, respectively, and the ripe peel essential oil was the weakest one. The growth of Saccharomyces cerevisiae was controlled in the treated orange juices. The antifungal activity of essential oils was increased by rising up in their concentration and decreased by passing time. Unripe and ripe essential oils showed the strongest and weakest anti yeast potential, respectively. Conclusions: The essential oils of leaves and ripe and unripe peels of bitter orange could be used as natural preservatives in food industry.

  12. Performance Analysis of Leaf Spring by Contact Mechanics Approach Based on the Nature of Material Properties

    OpenAIRE

    Sathish Gandhi, Veeramalai Chinnasamy; Kumaravelan, Radhakrishnan; Ramesh, Sengottuvelu; Joemax Agu, Maxwell Thompson

    2014-01-01

    In an automotive system, a curved leaf spring is used for the purpose of suspension and for reducing the transient vibration of the system. Composite materials are widely used in automobile industries as a replacement for steel to reduce the weight and to increase the strength of an automotive system. In this study, various materials have been considered for an analysis based on the Young modulus-to-yield strength ratio. The study has been carried out by considering the material properties. T...

  13. The Changes of Photosynthetic Properties and Cell Microstructure in Peanut Leaves during Leaf Senescence

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-dong; WANG Xiao-yun; YU Song-lie; ZHANG Gao-ying; WAN Yong-shan; LI Jun

    2002-01-01

    The changes of photosynthetic properties and cell microstructure in peanut leaves during leaf senescence were studied with two high-yielding peanut cultivars (cv. Luhua11 and Fu8707). The main results showed that during the whole process of leaf growth and senescence, changes in the photosynthesis rate (Pn)and contents of chlorophyll in leaves, could be described with a parabolic function, y = A + Bx + Cx2 (where y refers to the values of the above parameters and x to the days after leaf unfolding). During peanut leaf senescence, the shape of chloroplast changed gradually from long ellipses to circles. The starch globule in chloroplast altered gradually from more and larger sizes to fewer and smaller, but the oil globule from fewer and smaller to more and larger. The grana lamellae varied progressively: from thinness and length to thickness and shortness; from ranking along the long axle direction of chloroplast to disorderly arrangment and finally blurring.At last, the membrane envelope of chloroplast broke, so the inclusion seeped out to the cell and the chloroplast broke up.

  14. Effects of Organic and Chemical Fertilizers on Leaf Yield, Essential Oil Content and Composition of Lemon Verbena (Lippia citriodora Kunth

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Ebadi

    2017-02-01

    Full Text Available Introduction: Organic fertilizers with beneficial effects on soil structure and nutrient availability help maintain yield and quality, and they are less costly than synthetic fertilizers. Vermicompost and vermiwash are two organic fertilizers that they contain a biologically active mixture of bacteria, enzymes and phytohormones, also these organic fertilizers can supply the nutritional needs of plants. Lemon verbena (Lippia citriodora Kunth, Verbenaceae is an evergreen perennial aromatic plant. The lemon-scented essential oil from the lemon verbena has been widely used for its digestive, relaxing, antimalarial and lemony flavor properties. In order to decrease the use of chemical fertilizers for reduction of environmental pollution, this research was undertaken to determine effects of vermicompost and vermiwash in comparison with chemical fertilizer on leaf yield, essential oil content and composition of lemon verbena. Materials and Methods: A pot experiment based on a completely randomized design with six treatments and three replications on Lemon verbena was carried out in the experimental greenhouse of the Department of Horticulture Sciences, Tarbiat Modares University, 2012. Treatments consisted of 10, 20 and 30 % by volume of vermicompost and vermiwash (with an addition to irrigation in three steps, including: two weeks after the establishment of plants in pots, the appearing of branches and three weeks before harvest, complete fertilizer and control without any fertilizer. Each replication contained six pots and each pot contained one plant of Lemon verbena provided from Institute of Medicinal Plants, Karaj, therefore 108 pots were used in this experiment. The pots were filled up by a mixture contained 3/5 soil and 2/5 sand (v/v. After three months, plant aerial parts were harvested concomitantly at starting of the flowering stage. Aerial parts were dried at room temperature for 72 hours and dry weights of dried branches and leaves were

  15. Chemical and thermal properties of VIP latrine sludge

    African Journals Online (AJOL)

    2015-07-04

    Jul 4, 2015 ... 1Pollution Research Group, Department of Chemical Engineering, University ... Keywords: faecal sludge, VIP latrines, chemical properties, thermal properties ..... In: Proceedings of the EWB-UK National Research & Education.

  16. Evolutionary Position and Leaf Toughness Control Chemical Transformation of Litter, and Drought Reinforces This Control: Evidence from a Common Garden Experiment across 48 Species.

    Science.gov (United States)

    Pan, Xu; Song, Yao-Bin; Jiang, Can; Liu, Guo-Fang; Ye, Xue-Hua; Xie, Xiu-Fang; Hu, Yu-Kun; Zhao, Wei-Wei; Cui, Lijuan; Cornelissen, Johannes H C; Dong, Ming; Prinzing, Andreas

    2015-01-01

    Plant leaf litter is an important source of soil chemicals that are essential for the ecosystem and changes in leaf litter chemical traits during decomposition will determine the availability of multiple chemical elements recycling in the ecosystem. However, it is unclear whether the changes in litter chemical traits during decomposition and their similarities across species can be predicted, respectively, using other leaf traits or using the phylogenetic relatedness of the litter species. Here we examined the fragmentation levels, mass losses, and the changes of 10 litter chemical traits during 1-yr decomposition under different environmental conditions (within/above surrounding litter layer) for 48 temperate tree species and related them to an important leaf functional trait, i.e. leaf toughness. Leaf toughness could predict the changes well in terms of amounts, but poorly in terms of concentrations. Changes of 7 out of 10 litter chemical traits during decomposition showed a significant phylogenetic signal notably when litter was exposed above surrounding litter. These phylogenetic signals in element dynamics were stronger than those of initial elementary composition. Overall, relatively hard-to-measure ecosystem processes like element dynamics during decomposition could be partly predicted simply from phylogenies and leaf toughness measures. We suggest that the strong phylogenetic signals in chemical ecosystem functioning of species may reflect the concerted control by multiple moderately conserved traits, notably if interacting biota suffer microclimatic stress and spatial isolation from ambient litter.

  17. Evolutionary Position and Leaf Toughness Control Chemical Transformation of Litter, and Drought Reinforces This Control: Evidence from a Common Garden Experiment across 48 Species.

    Directory of Open Access Journals (Sweden)

    Xu Pan

    Full Text Available Plant leaf litter is an important source of soil chemicals that are essential for the ecosystem and changes in leaf litter chemical traits during decomposition will determine the availability of multiple chemical elements recycling in the ecosystem. However, it is unclear whether the changes in litter chemical traits during decomposition and their similarities across species can be predicted, respectively, using other leaf traits or using the phylogenetic relatedness of the litter species. Here we examined the fragmentation levels, mass losses, and the changes of 10 litter chemical traits during 1-yr decomposition under different environmental conditions (within/above surrounding litter layer for 48 temperate tree species and related them to an important leaf functional trait, i.e. leaf toughness. Leaf toughness could predict the changes well in terms of amounts, but poorly in terms of concentrations. Changes of 7 out of 10 litter chemical traits during decomposition showed a significant phylogenetic signal notably when litter was exposed above surrounding litter. These phylogenetic signals in element dynamics were stronger than those of initial elementary composition. Overall, relatively hard-to-measure ecosystem processes like element dynamics during decomposition could be partly predicted simply from phylogenies and leaf toughness measures. We suggest that the strong phylogenetic signals in chemical ecosystem functioning of species may reflect the concerted control by multiple moderately conserved traits, notably if interacting biota suffer microclimatic stress and spatial isolation from ambient litter.

  18. Chemical control of anthrachnose of Sansevieria trisfasciata var. Hahnii on a detached-leaf system.

    Directory of Open Access Journals (Sweden)

    Gerardo Pérez-León

    2015-06-01

    Full Text Available The objective of this work was to assess fungicides to combat Sansevieria trifasciata var. Hahnii anthracnose. Twelve fungicides (alone or in mixture were evaluated on the infection and severity of C. sansevieriae on a detached- leaf system. Fungicides used were azoxystrobin, boscalid + pyraclostrobin, carbendazim + mancozeb, difenoconazole, epoxiconazole + carbendazim, folpet, imazalil, thiophanate-methyl + mancozeb, myclobutanil, and prochloraz. The study was carried out at the Plant Biotechnology Laboratory of the Agricultural Research Center of the University of Costa Rica, during the first semester of 2012. Each chemical treatment was applied by aspersion on the day of inoculation (0 dai or three days after it (3 dai. The number and diameter of the lesions were evaluated after seven, eleven and fifteen dai. Fungicide, application moment, fungicide x application moment interaction and fungicide x evaluation moment interaction significantly affected (p<0,0001 both evaluated variables. Azoxystrobin, boscalid + pyraclostrobin, carbendazim + mancozeb, epoxiconazole + carbendazim and thiophanate-methyl + mancozeb provided 100% protection to Sansevieria leaves throughout the evaluation period (15 days when applied the same day of inoculation (0 dai. After three days of inoculation (3 dai only epoxiconazole + carbendazim completely inhibited the pathogen establishment (zero incidence in the three evaluations when applied azoxystrobin and carbendazim + mancozeb, the incidence was 0% after seven and eleven days for the first treatment and after seven days for the second one.

  19. Chemical composition of the leaf and stem essential oil of Adenophorae Radix

    Science.gov (United States)

    Lan, Weijie; Lin, Shang; Li, Xindan; Zhang, Qing; Qin, Wen

    2017-03-01

    The chemical composition of the essential oil extracted from leaves and stems of Adenophorae Radix was determined for the first time in this study. Twenty-six compounds were identified by gas chromatography coupled to mass spectrometry (GC-MS). n-Hexadecanoic acid (29.14%), 9,12-octadecadienoic acid (Z,Z)- (17.22%), hexadecanoic acid, methyl ester(8.98%), 9-octadecenoic acid, methyl ester, (E)- (7.03%), 9,12-octadecadienoic acid (Z,Z)-, methyl ester (5.93%), phytol (5.50%), and estradiol (4.43%) were measured as the major compounds in stem oil. The leaf essential oil was dominated by n-hexadecanoic acid (50.78%), 9-octadecenoic acid, methyl ester, (E)- (9.04%), phytol (8.47%), d-mannitol (5.81%), 9,12,15-octadecatrienoic acid, methyl ester, (Z,Z,Z)- (4.31%), hexadecanoic acid, methyl ester (2.19%) and 9,12-octadecadienoic acid (Z,Z)-(1.7%). The leaves yield was 0.12% (v/w) and the stems yield showed only 0.073% (v/w). The results might provide reference basis for further exploration of its application value.

  20. Leaf habit does not determine the investment in both physical and chemical defences and pair-wise correlations between these defensive traits.

    Science.gov (United States)

    Moreira, X; Pearse, I S

    2017-05-01

    Plant life-history strategies associated with resource acquisition and economics (e.g. leaf habit) are thought to be fundamental determinants of the traits and mechanisms that drive herbivore pressure, resource allocation to plant defensive traits, and the simultaneous expression (positive correlations) or trade-offs (negative correlations) between these defensive traits. In particular, it is expected that evergreen species - which usually grow slower and support constant herbivore pressure in comparison with deciduous species - will exhibit higher levels of both physical and chemical defences and a higher predisposition to the simultaneous expression of physical and chemical defensive traits. Here, by using a dataset which included 56 oak species (Quercus genus), we investigated whether leaf habit of plant species governs the investment in both physical and chemical defences and pair-wise correlations between these defensive traits. Our results showed that leaf habit does not determine the production of most leaf physical and chemical defences. Although evergreen oak species had higher levels of leaf toughness and specific leaf mass (physical defences) than deciduous oak species, both traits are essentially prerequisites for evergreenness. Similarly, our results also showed that leaf habit does not determine pair-wise correlations between defensive traits because most physical and chemical defensive traits were simultaneously expressed in both evergreen and deciduous oak species. Our findings indicate that leaf habit does not substantially contribute to oak species differences in plant defence investment. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Engineering electrical properties of graphene: chemical approaches

    Science.gov (United States)

    Kim, Yong-Jin; Kim, Yuna; Novoselov, Konstantin; Hong, Byung Hee

    2015-12-01

    To ensure the high performance of graphene-based devices, it is necessary to engineer the electrical properties of graphene with enhanced conductivity, controlled work function, opened or closed bandgaps, etc. This can be performed by various non-covalent chemical approaches, including molecular adsorption, substrate-induced doping, polymerization on graphene, deposition of metallic thin films or nanoparticles, etc. In addition, covalent approaches such as the substitution of carbon atoms with boron or nitrogen and the functionalization with hydrogen or fluorine are useful to tune the bandgaps more efficiently, with better uniformity and stability. In this review, representative examples of chemically engineered graphene and its device applications will be reviewed, and remaining challenges will be discussed.

  2. Octenidine dihydrochloride: chemical characteristics and antimicrobial properties.

    Science.gov (United States)

    Assadian, Ojan

    2016-03-01

    The empiric use of antibiotics is being restricted due to the spread of antimicrobial resistance. However, topical antiseptics are less likely to induce resistance, owing to their unspecific mode of action and the high concentrations in which they can be used. One such antiseptic, octenidine dihydrochloride (OCT), can be used either prophylactically or therapeutically on the skin, mucosa and wounds. Evidence to support its use comes from in-vitro, animal and clinical studies on its safety, tolerability and efficacy. This article summarises the physical, chemical and antimicrobial properties of OCT in the context of wound care.

  3. Arbutus unedo L.: chemical and biological properties.

    Science.gov (United States)

    Miguel, Maria G; Faleiro, Maria L; Guerreiro, Adriana C; Antunes, Maria D

    2014-09-30

    Arbutus unedo L. (strawberry tree) has a circum-Mediterranean distribution, being found in western, central and southern Europe, north-eastern Africa (excluding Egypt and Libya) and the Canary Islands and western Asia. Fruits of the strawberry tree are generally used for preparing alcoholic drinks (wines, liqueurs and brandies), jams, jellies and marmalades, and less frequently eaten as fresh fruit, despite their pleasing appearance. An overview of the chemical composition of different parts of the plant, strawberry tree honey and strawberry tree brandy will be presented. The biological properties of the different parts of A. unedo and strawberry tree honey will be also overviewed.

  4. Arbutus unedo L.: Chemical and Biological Properties

    Directory of Open Access Journals (Sweden)

    Maria G. Miguel

    2014-09-01

    Full Text Available Arbutus unedo L. (strawberry tree has a circum-Mediterranean distribution, being found in western, central and southern Europe, north-eastern Africa (excluding Egypt and Libya and the Canary Islands and western Asia. Fruits of the strawberry tree are generally used for preparing alcoholic drinks (wines, liqueurs and brandies, jams, jellies and marmalades, and less frequently eaten as fresh fruit, despite their pleasing appearance. An overview of the chemical composition of different parts of the plant, strawberry tree honey and strawberry tree brandy will be presented. The biological properties of the different parts of A. unedo and strawberry tree honey will be also overviewed.

  5. Chemical constituents and antimicrobial activity of the ethanol extracts obtained from the flower, leaf and stem of Salvia officinalis L.

    Directory of Open Access Journals (Sweden)

    MIHAILO S. RISTIC

    2003-01-01

    Full Text Available In this paper a comparison of the chemical composition and antimicrobial action of the ethanol extracts from the flower, leaf and stem of the herbal species Salvia officinalis L. (Lamiaceae, originating from the southeast region of Serbia was carried out. The chemical composition of the extracts was determined by GC-FID and GC-MS analyses. Manool has the highest level of all the components (9.0–11.1 %. Antimicrobial activity was determined by the diffusion and dilution method, whereby the latter one was modified by use of cellulose discs, and it was applied for the determination of the minimal inhibitory (MIC and minimal lethal concentrations (MLC. The leaf extract has a stronger antimicrobial activity than those of the flower and stem.

  6. Property Modelling for Applications in Chemical Product and Process Design

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    Physical-chemical properties of pure chemicals and their mixtures play an important role in the design of chemicals based products and the processes that manufacture them. Although, the use of experimental data in design and analysis of chemicals based products and their processes is desirable...... such as database, property model library, model parameter regression, and, property-model based product-process design will be presented. The database contains pure component and mixture data for a wide range of organic chemicals. The property models are based on the combined group contribution and atom...... modeling tools in design and analysis of chemical product-process design, including biochemical processes will be highlighted....

  7. Chemical Compositions and Biological Activities of Leaf Essential Oils of Six Species of Annonaceae from Monteverde, Costa Rica

    Directory of Open Access Journals (Sweden)

    Maria C. Palazzo

    2009-06-01

    Full Text Available The leaf essential oils of six members of the Annonaceae from Monteverde, Costa Rica (Desmopsis bibracteata, Desmopsis microcarpa, Guatteria costaricensis, Guatteria diospyroides, Guatteria oliviformis, and Unonopsis costaricensis have been obtained by hydrodistillation and analyzed by GC-MS in order to compare and contrast the volatile chemical compositions of these species. The essential oils were screened for in-vitro cytotoxic activity against MDA-MB-231 and Hs 578T human breast tumor cells, and antibacterial activity against Bacillus cereus, Staphylococcus aureus, and Escherichia coli. The principal components of D. bibracteata were germacrene D (29.9%, (E-caryophyllene (11.5%, and δ-cadinene (9.2%. D. microcarpa was dominated by bicyclogermacrene (45.5% and germacrene D (28.3%. G. costaricensis was rich in α- and β-pinenes (36.3% and 48.2%, respectively. The leaf oil of G. diospyroides was composed largely of germacrene D (46.4%, (Z-β-ocimene (17.4%, (E-β-ocimene (12.0%, and (E-caryophyllene (10.3%. Germacrene D dominated the leaf oil of G. oliviformis (73.3% as well as U. costaricensis (62.9%. The leaf essential oils of D. bibracteata, G. diospyroides, G. oliviformis, and U. costaricensis, showed notable cytotoxicity on MDA-MB-231 cells ( ³ 99% kill at 100 m g/mL but only D. bibracteata leaf oil was cytotoxic to Hs 578T. D. bibracteata, G. diospyroides, G. oliviformis, and U. costaricensis leaf oils showed marginal antibacterial activity against B. cereus (MIC = 156 m g/mL. A cluster analysis of Guatteria species, based on the abundant essential oil components, has revealed a spathulenol-rich cluster (Brazilian species and a germacrene D cluster (Costa Rican species.

  8. Chemical composition of abaca (Musa textilis) leaf fibers used for manufacturing of high quality paper pulps.

    Science.gov (United States)

    del Río, José C; Gutiérrez, Ana

    2006-06-28

    The chemical composition of leaf fibers of abaca (Musa textilis), which are commonly used for high-quality paper pulp production, was thoroughly studied. The results revealed that the lignin content was 13.2% of the total fiber. The analysis of abaca fibers by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS) released predominantly compounds arising from lignin and p-hydroxycinnamic acids, with high amounts of 4-vinylphenol. The latter compound was demonstrated to arise from p-coumaric acid by pyrolysis of abaca fibers in the presence of tetramethylammonium hydroxide, which released high amounts of p-coumaric acid (as the methyl derivative). Products from p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) propanoid units, with a predominance of the latter (H:G:S molar ratio of 1.5:1:4.9), were also released after Py-GC/MS of abaca fibers. Sinapyl and coniferyl acetates, which are thought to be lignin monomer precursors, were also found in abaca. The extractives content of the abaca fiber (0.4%) was low, and the most predominant compounds were free sterols (24% of total extract) and fatty acids (24% of total extract). Additionally, significant amounts of steroid ketones (10%), triglycerides (6%), omega-hydroxyfatty acids (6%), monoglycerides (4%), fatty alcohols (4%), and a series of p-hydroxycinnamyl (p-coumaric and ferulic acids) esterified with long chain alcohols and omega-hydroxyfatty acids were also found, together with minor amounts of steroid hydrocarbons, diglycerides, alpha-hydroxyfatty acids, sterol esters, and sterol glycosides.

  9. Acaricidal properties of Ricinus communis leaf extracts against organophosphate and pyrethroids resistant Rhipicephalus (Boophilus) microplus.

    Science.gov (United States)

    Ghosh, Srikanta; Tiwari, Shashi Shankar; Srivastava, Sharad; Sharma, Anil Kumar; Kumar, Sachin; Ray, D D; Rawat, A K S

    2013-02-18

    Indian cattle ticks have developed resistance to commonly used acaricides and an attempt has been made to formulate an ecofriendly herbal preparation for the control of acaricide resistant ticks. A 95% ethanolic extract of Ricinus communis was used to test the efficacy against reference acaricide resistant lines by in vitro assay. In in vitro assay, the extract significantly affects the mortality rate of ticks in dose-dependent manner ranging from 35.0 ± 5.0 to 95.0 ± 5.0% with an additional effect on reproductive physiology of ticks by inhibiting 36.4-63.1% of oviposition. The leaf extract was found effective in killing 48.0, 56.7 and 60.0% diazinon, deltamethrin and multi-acaricide resistant ticks, respectively. However, the cidal and oviposition limiting properties of the extract were separated when the extract was fractionated with hexane, chloroform, n-butanol and water. The HPTLC finger printing profile of R. communis leaf extract under λ(max.) - 254 showed presence of quercetin, gallic acid, flavone and kaempferol which seemed to have synergistic acaricidal action. In vivo experiment resulted in 59.9% efficacy on Ist challenge, however, following 2nd challenge the efficacy was reduced to 48.5%. The results indicated that the 95% ethanolic leaf extract of R. communis can be used effectively in integrated format for the control of acaricide resistant ticks.

  10. Composition of Chicory Root, Peel, Seed and Leaf Ethanol Extracts and Biological Properties of Their Non-Inulin Fractions

    Directory of Open Access Journals (Sweden)

    Joanna Milala

    2011-01-01

    Full Text Available The chemical composition of the ethanol extracts of chicory root, peel, seed and leaf has been determined, in particular their inulin and phenolic fractions. The root and peel extracts were characterized by large mass fractions of inulin (60.1 and 46.8 g per 100 g of fresh mass, respectively, predominantly with degree of polymerization in the range from 3 to 10, while phenolics, determined as caffeoylquinic acids, made up 0.5 and 1.7 g per 100 g of fresh mass, respectively. The leaf and seed extracts had decidedly lower mass fractions of inulin (1.7 and 3.2 g per 100 g of fresh mass, respectively and higher mass fractions of phenolics (9.6 and 4.22 g per 100 g of fresh mass, respectively recognized as caffeoylquinic acids, chicoric acid and quercetin glucuronide. The biological properties of a non-inulin fraction from each extract were determined on Wistar rats fed with diets rich in fructose and saturated fat, as a model of metabolic changes related to westernization of human eating habits. The diets contained the same amount of inulin (6 % with various phenolic fractions. Some changes were noted in the microbial enzymatic activity of the caecum after feeding for 4 weeks with the diet containing the highest mass fraction of phenolics (0.208 %, derived from the mixture of peel and seed extracts (decreased activity of β-galactosidase and β-glucuronidase, as well as with the diet containing leaf extract (decreased β-glucuronidase activity. All the diets showed no essential influence on the caecal concentration and profile of short-chain fatty acids, except acetate, whose concentration decreased significantly in rats fed with the diet enriched with root extract. The addition of peel and leaf extracts to the fructose diets significantly increased the serum antioxidant capacity of lipophilic substances. The study indicates that parts of chicory and its byproducts might be a source of valuable compounds to improve the physiological activity of

  11. In vitro evaluation of the cytotoxic and apoptogenic properties of aloe whole leaf and gel materials.

    Science.gov (United States)

    du Plessis, Lissinda H; Hamman, Josias H

    2014-04-01

    Aloe gel and whole-leaf materials have shown biological effects with potential therapeutic applications, and recently, their drug-absorption enhancement properties have been discovered. It is important to establish a safety profile for these materials before they can be used in pharmaceutical products. The aim of the study was to investigate the in vitro cytotoxicity of Aloe vera, Aloe marlothii, Aloe speciosa and Aloe ferox against human hepatocellular (HepG2), human neuroblastoma cells (SH-SY5Y) and human adenocarcinoma epithelial cells (HeLa). Flow cytometry was used to measure cell viability, apoptosis and reactive oxygen species (ROS). The aloe gel materials investigated only decreased cell viability at concentrations of >10 mg/mL and exhibited half-maximal cytotoxic concentration (CC(50)) values above 1000 mg/mL, except for A. vera gel in HepG2 cells (CC(50) = 269.3 mg/mL). A. speciosa whole-leaf material showed a significant decrease in viability of Hela cells, whereas the other whole-leaf materials did not show a similar effect. The aloe gel materials in general showed low levels of apoptosis, whereas A. vera and A. speciosa whole-leaf materials caused a dose-dependent increase of apoptosis in HeLa cells. None of the aloe materials investigated exhibited a significant increase in ROS. It can be concluded that the selected aloe materials caused only limited reduction in cell viability with limited in vitro cytotoxicity effects. Further, neither significant apoptosis effects were observed nor induction of ROS.

  12. Characterization of the antioxidant properties of hydrophilic and lipophilic extracts of Jute (Corchorus olitorius) leaf.

    Science.gov (United States)

    Oboh, G; Raddatz, H; Henle, T

    2009-01-01

    Corchorus olitorius (jute) is a native plant of tropical Africa and Asia, and has since spread to Australia, South America and some parts of Europe. Its leafy vegetable is popularly used in soup preparation and folk medicine for the treatment of fever, chronic cystitis, cold and tumours. A comparative study of the antioxidant properties of hydrophilic extract (HE) and lipophilic extract (LE) constituents of the leafy vegetable has been assessed. HE and LE of the leaf were prepared using water and hexane, respectively and their antioxidant properties were determined. HE had a significantly higher (P0.05) in their Fe(II) chelating ability (HE, 57.7-66.7%; LE, 56.4-61.1%). The higher 1,1-diphenyl-2-picrylhydrazyl radical-scavenging ability, reducing power and trolox equivalent antioxidant capacity of the hydrophilic extract may be due to its significantly higher (P<0.05) total phenol (630.8 mg/100 g), total flavonoid (227.8 mg/100 g) and non-flavonoid polyphenols (403.0 mg/100 g), and its high ascorbic acid content (32.6 mg/100 g). While the higher OH. scavenging ability of LE may be due to its high total carotenoid content (42.5 mg/100 g). Therefore, the additive/synergistic antioxidant activities of the hydrophilic and lipophilic constituents may contribute to the medicinal properties of C. olitorius leaf.

  13. Rediscovering leaf optical properties: New insights into plant acclimation to solar UV radiation.

    Science.gov (United States)

    Barnes, Paul W; Flint, Stephan D; Ryel, Ronald J; Tobler, Mark A; Barkley, Anne E; Wargent, Jason J

    2015-08-01

    The accumulation of UV-absorbing compounds (flavonoids and other phenylpropanoid derivatives) and resultant decrease in the UV transmittance of the epidermis in leaves (TUV), is a primary protective mechanism against the potentially deleterious effects of UV radiation and is a critical component of the overall acclimation response of plants to changing UV environments. Traditional measurements of TUV were laborious, time-consuming and destructive or invasive, thus limiting their ability to efficiently make multiple measurements of the optical properties of plants in the field. The development of rapid, nondestructive optical methods of determining TUV has permitted the examination of UV optical properties of leaves with increased replication, on a finer time scale, and enabled repeated sampling of the same leaf over time. This technology has therefore allowed for studies examining acclimation responses to UV in plants in ways not previously possible. Here we provide a brief review of these earlier studies examining leaf UV optical properties and some of their important contributions, describe the principles by which the newer non-invasive measurements of epidermal UV transmittance are made, and highlight several case studies that reveal how this technique is providing new insights into this UV acclimation response in plants, which is far more plastic and dynamic than previously thought.

  14. Vibrational Analysis and Mechanical Properties of Epoxy Composite Material for Automobile Leaf Spring

    Directory of Open Access Journals (Sweden)

    M. Prabhakaran

    2015-07-01

    Full Text Available The composites have found extensive application in various fields. The aim of this work is to analyze the mechanical properties and damping effect of the laminates of the composites. The vibration in the composite material that to be used in the application of automobiles for the purpose of leaf spring has to be reduced. So the damping capacity of the composites was found out. Also the tensile and impact properties were studied using existing ASTM standard testing procedures and the results are reported. Based on the experimental study, it is observed that the tensile and impact strength are similar to that of steel. After studying the tensile strength, impact strength, damping capacity and water absorption of the composite, it is useful in suggesting the different types of composites, may be hybrid or may be with uni-directional fiber or with some other fibers, so that the required mechanical properties is achieved.

  15. Chemical properties of peat used in balneology

    Science.gov (United States)

    Szajdak, L.; Hładoń, T.

    2009-04-01

    The physiological activity of peats is observed in human peat-bath therapy and in the promotion of growth in some plants. Balneological peat as an ecologically clean and natural substance is perceived as being more 'human friendly' than synthetic compounds. Poland has a long tradition of using balneological peat for therapeutic purposes. Balneological peat reveals a physical effect by altering temperature and biochemical effects through biologically active substances. It is mainly used for the treatment of rheumatic diseases that are quite common in Poland. Peat represents natural product. Physico-chemical properties of peat in particular surface-active, sorption and ion exchanges, defining their biological function, depend mainly on the chemical composition and molecular structure of humic substances representing the major constituent of organic soil (peat). The carbon of organic matter of peats is composed of 10 to 20% carbohydrates, primarily of microbial origin; 20% nitrogen-containing constituents, such as amino acids and amino sugars; 10 to 20% aliphatic fatty acids, alkanes, etc.; with the rest of carbon being aromatic. For balneology peat should be highly decomposed (preferably H8), natural and clean. The content of humic acids should exceed 20% of dry weight, ash content will be less than 15 15% of dry weight, sulphur content less than 0.3% of dry weight and the amount of water more than 85%. It will not contain harmful bacteria and heavy metals. Humic substances (HS) of peat are known to be macromolecular polydisperse biphyllic systems including both hydrophobic domains (saturated hydrocarbon chains, aromatic structural units) and hydrophilic functional groups, i. e having amphiphilic character. Amphiphilic properties of FA are responsible for their solubility, viscosity, conformation, surfactant-like character and a variety of physicochemical properties of considerable biologically practical significance. The chemical composition of peats depends

  16. QSPR prediction of physico-chemical properties for REACH.

    Science.gov (United States)

    Dearden, J C; Rotureau, P; Fayet, G

    2013-01-01

    For registration of a chemical, European Union REACH legislation requires information on the relevant physico-chemical properties of the chemical. Predicted property values can be used when the predictions can be shown to be valid and adequate. The relevant physico-chemical properties that are amenable to prediction are: melting/freezing point, boiling point, relative density, vapour pressure, surface tension, water solubility, n-octanol-water partition coefficient, flash point, flammability, explosive properties, self-ignition temperature, adsorption/desorption, dissociation constant, viscosity, and air-water partition coefficient (Henry's law constant). Published quantitative structure-property relationship (QSPR) methods for all of these properties are discussed, together with relevant property prediction software, as an aid for those wishing to use predicted property values in submissions to the European Chemicals Agency (ECHA).

  17. Chemical investigation of the leaf and rhizome essential oils of Zingiber zerumbet (L. Smith from Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammad Nazrul Islam Bhuiyan

    2009-03-01

    Full Text Available Zingiber zerumbet (L. Smith leaf and rhizome oils, obtained by hydrodistillation, were analyzed by gas chromatography mass spectroscopy (GC-MS. Twenty-nine components were identified in the leaf oil. The major components were zerumbone (36.98%; a-caryophyllene (16.35% and camphene (9.24%. Thirty components were identified in rhizome oil with the main components being in zerumbone (46.83%; a-caryophyllene (19.00% and 1,5,5,8-tetramethyl-12-oxabicyclo[9.1.0]dodeca-3,7-diene (4.28%. The compositions of both oils varied qualitatively and quantitatively.

  18. Property Modelling for Applications in Chemical Product and Process Design

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    Physical-chemical properties of pure chemicals and their mixtures play an important role in the design of chemicals based products and the processes that manufacture them. Although, the use of experimental data in design and analysis of chemicals based products and their processes is desirable...... such as database, property model library, model parameter regression, and, property-model based product-process design will be presented. The database contains pure component and mixture data for a wide range of organic chemicals. The property models are based on the combined group contribution and atom......, polymers, mixtures as well as separation processes. The presentation will highlight the framework (ICAS software) for property modeling, the property models and issues such as prediction accuracy, flexibility, maintenance and updating of the database. Also, application issues related to the use of property...

  19. The Aloe vera phenomenon: a review of the properties and modern uses of the leaf parenchyma gel.

    Science.gov (United States)

    Grindlay, D; Reynolds, T

    1986-06-01

    The mucilaginous gel from the parenchymatous cells in the leaf pulp of Aloe vera has been used since early times for a host of curative purposes. This gel should be distinguished clearly from the bitter yellow exudate originating from the bundle sheath cells, which is used for its purgative effects. Aloe vera gel has come to play a prominent role as a contemporary folk remedy, and numerous optimistic, and in some cases extravagant, claims have been made for its medicinal properties. Modern clinical use of the gel began in the 1930s, with reports of successful treatment of X-ray and radium burns, which led to further experimental studies using laboratory animals in the following decades. The reports of these experiments and the numerous favourable case histories did not give conclusive evidence, since although positive results were usually described, much of the work suffered from poor experimental design and insufficiently large test samples. In addition some conflicting or inconsistent results were obtained. With the recent resurgence of interest in Aloe vera gel, however, new experimental work has indicated the possibility of distinct physiological effects. Chemical analysis has shown the gel to contain various carbohydrate polymers, notably either glucomannans or pectic acid, along with a range of other organic and inorganic components. Although many physiological properties of the gel have been described, there is no certain correlation between these and the identified gel components.

  20. Physico-chemical surface properties of microalgae.

    Science.gov (United States)

    Ozkan, Altan; Berberoglu, Halil

    2013-12-01

    This study reports a comprehensive set of experimentally measured physico-chemical surface properties of 12 different microalgae including fresh and seawater species of green algae, diatoms and cyanobacteria. The surface free energy and its components including the acid-base (AB), van der Waals (LW), electron donor/acceptor parameters were quantified based on contact angle measurements along with the Lifshitz-van der Waals acid-base approach using the probe liquid surface tension parameters proposed by van Oss et al. as well as by Della Volpe and Siboni. Moreover, the zeta and surface potentials of all species were determined using electrophoretic mobility measurements along with using Smoluchowski's model. Finally, the free energy of cohesion of the microalgae was also determined based on the calculated surface energy properties. The results showed that the electron donor parameter correlated well with the free energy of cohesion in all groups of microalgae. Moreover, species known to form colonies and exhibit benthic cultures had distinctly hydrophobic surfaces compared to microalgae prefering planktonic growth. These results indicate the importance of surface hydrophobicity for causing biofouiling or flocculation of cultures. Finally, the zeta potentials did not show a distinctive trend with the types of microalgae but the surface potentials were markedly larger for the salt water species. The reported methods and data are expected to provide critical information for researchers and technology developers concerned with cell to cell and cell to substrata interactions of microalgae in algal biomass cultivation and harvesting, biofouling of membranes and surfaces, as well as cell-surface interactions in photosynthetic microbial fuel cell technologies.

  1. Optical and photocatalytic properties of Corymbia citriodora leaf extract synthesized ZnS nanoparticles

    Science.gov (United States)

    Chen, Jinfeng; Hu, Binjie; Zhi, Jinhu

    2016-05-01

    ZnS nanoparticles were biosynthesized via a green and simple method using Corymbia citriodora leaf extract as reducing and stabilizing agent. The biosynthesized ZnS nanoparticles were in the size range of 45 nm with a surface plasmon resonance band at 325 nm. XRD analysis revealed that the nanoparticles were in the sphalerite phase. Quantum confinement effects of biosynthesized ZnS nanoparticles were observed using photoluminescence spectroscopy. The photocatalytic activity of the ZnS nanoparticles has been investigated by degradation methylene blue under UV light irradiation. Due to the smaller size and excellent dispersicity, the biosynthesized ZnS nanoparticles showed a superior photocatalytic performance compared with that of chemical synthesize ZnS nanoparticles.

  2. Chemical composition of the leaf essential oils of Murraya koenigii (L.) Spreng and Murraya paniculata (L.) Jack

    OpenAIRE

    Jasim Uddin Chowdhury; Mohammad Nazrul Islam Bhuiyan; Mohammed Yusuf

    2008-01-01

    The chemical composition of the leaf oils of Murraya koenigii (L.) Spreng and M. paniculata (L.) Jack from Bangladesh was studied by gas chromatography mass spectroscopy (GC-MS). M. koenigii oil contained 39 compounds of which the major is 3-carene (54.2%) followed by caryophyllene (9.5%). Oil of M. paniculata contained 58 compounds of which the major are caryophyllene oxide (16.6%), b-caryophyllene (11.8%), spathulenol (10.2%), b-elemene (8.9%), germacrene D (6.9%) and cyclooctene, 4-methyle...

  3. Chemical composition of the leaf essential oils of Murraya koenigii (L. Spreng and Murraya paniculata (L. Jack

    Directory of Open Access Journals (Sweden)

    Jasim Uddin Chowdhury

    2008-06-01

    Full Text Available The chemical composition of the leaf oils of Murraya koenigii (L. Spreng and M. paniculata (L. Jack from Bangladesh was studied by gas chromatography mass spectroscopy (GC-MS. M. koenigii oil contained 39 compounds of which the major is 3-carene (54.2% followed by caryophyllene (9.5%. Oil of M. paniculata contained 58 compounds of which the major are caryophyllene oxide (16.6%, b-caryophyllene (11.8%, spathulenol (10.2%, b-elemene (8.9%, germacrene D (6.9% and cyclooctene, 4-methylene-6-(1-propenylidene (6.4%. The compositions of both oils varied qualitatively and quantitatively.

  4. Leaf tissues proportion and chemical composition of Axonopus jesuiticus x A. scoparius as a function of pig slurry application

    Directory of Open Access Journals (Sweden)

    Cristiano Reschke Lajús

    2014-02-01

    Full Text Available This study aimed to evaluate the chemical and anatomical attributes of leaves of giant missionary grass to application of 0, 62, 124, 186, 248 and 310m³ ha-1 of pig slurry. At 83 days after the last application of fertilizer, the leaf blades were collected, fixed in FAA 70%, sectioned, stained, photographed and digitalized. The transversal section of leaf blades were evaluated for proportion of epidermis, lignified vascular tissue + sclerenchyma, non-lignified vascular tissue and parenchyma with an image-processing system calibrated to 1mm pixel-1. Leaf samples were analyzed for crude protein, acid detergent fiber, neutral detergent fiber and hemicellulose content by near infrared reflectance spectroscopy. The pig slurry application up to 310m³ ha-1 significantly increased the percentage of crude protein, parenchyma, epidermis, non-lignified vascular tissue and hemicellulose, while decreasing the percentage of acid detergent fiber and lignified vascular tissue + sclerenchyma. The Pearson's correlation was positive between crude protein and non-lignified vascular tissue, and between acid detergent fiber and lignified vascular tissue + sclerenchyma. The percentage of hemicellulose was positively correlated with epidermis, parenchyma and non-lignified vascular tissue. A negative correlation between acid detergent fiber and epidermis, parenchyma and non-lignified vascular tissue was observed.

  5. Chemical composition and larvicidal activity of leaf essential oil from Clausena anisata (Willd.)Hook. f. exBenth (Rutaceae) against three mosquito species

    Institute of Scientific and Technical Information of China (English)

    Marimuthu Govindarajan

    2010-01-01

    Objective:To determine the mosquito larvicidal activity of leaf essential oil and their chemical constituents fromClausena anisata(C. anisata) (Willd.) Hook. f. ex Benth. against Culex quinquefasciatus, Aedes aegypti andAnopheles Stephensi.Methods:Essential oil was obtained by hydro-distillation and the chemical composition of the leaf essential oil was analyzed using gas chromatography-mass spectrometry. The mosquitoes were reared in the vector control laboratory and twenty late III instar larvae of three mosquito species were exposed to based on the wide range and narrow range tests, essential oil was tested at50, 100, 150, 200 and 250 ppm and each compound was tested at various concentration (5-75 ppm) and were assayed in the laboratory by using the protocol ofWHO 2005; the 24 hLC50 values of theC. anisata leaf essential oil and their major compounds were determined following Probit analysis.Results:The oil contained were mainly β-pinene (32.8%), sabinene(28.3%), germacrene-D (12.7%), estragole (6.4%) and linalool(5.9%). The essential oil from the leaves ofC. anisataexhibited significant larvicidal activity, with24 hLC50 values of140.96, 130.19 and119.59ppm, respectively. The five pure constituents extracted from theC. anisata leaf essential oil were also tested individually against three mosquito larvae. The LC50values of β-pinene, sabinene, germacrene-D, estragole and linalool appeared to be most effective againstAnopheles stephensi(LC50-23.17, 19.67, 16.95, 11.01, 35.17ppm) followed byAedes aegypti (LC50-27.69, 21.20,18.76, 12.70, 38.64 ppm) and Culex quinquefasciatus(LC50-32.23, 25.01, 21.28, 14.01, 42.28).Conclusions:The essential oil of C. anisata contains five major compounds and has remarkable larvicidal properties, which may be considered as a potent source for the production of natural larvicides.

  6. Antimalarial properties of Artemisia vulgaris L. ethanolic leaf extract in a Plasmodium berghei murine malaria model

    Directory of Open Access Journals (Sweden)

    Gayan S. Bamunuarachchi

    2013-12-01

    Full Text Available Background & objectives: Artemisinin isolated from Artemisia annua is the most potent antimalarial drug against chloroquine-resistant Plasmodium falciparum malaria. Artemisia vulgaris, an invasive weed, is the only Artemisia species available in Sri Lanka. A pilot study was undertaken to investigate the antiparasitic activity of an A. vulgaris ethanolic leaf extract (AVELE in a P. berghei ANKA murine malaria model that elicits pathogenesis similar to falciparum malaria. Methods: A 4-day suppressive and the curative assays determined the antiparasitic activity of AVELE using four doses (250, 500, 750 and 1000 mg/kg, Coartem® as the positive control and 5% ethanol as the negative control in male ICR mice infected with P. berghei. Results: The 500, 750 and 1000 mg/kg doses of AVELE significantly (p ≤0.01 inhibited parasitaemia by 79.3, 79.6 and 87.3% respectively, in the 4-day suppressive assay, but not in the curative assay. Chronic administration of the high dose of AVELE ruled out overt signs of toxicity and stress as well as hepatotoxicity, renotoxicity and haematotoxicity. Interpretation & conclusion: The oral administration of a crude ethonolic leaf extract of A. vulgaris is non-toxic and possesses potent antimalarial properties in terms of antiparasitic activity.

  7. The chemical and environmental property space of REACH chemicals.

    Science.gov (United States)

    Öberg, Tomas; Iqbal, M Sarfraz

    2012-05-01

    The European regulation on chemicals, REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), came into force on 1 June 2007. With pre-registration complete in 2008, data for these substances may provide an overview of the expected chemical space and its characteristics. In this paper, using various in silico computation tools, we evaluate 48782 neutral organic compounds from the list to identify hazardous and safe compounds. Two different classification schemes (modified Verhaar and ECOSAR) identified between 17% and 25% of the compounds as expressing only baseline toxicity (narcosis). A smaller portion could be identified as reactive (19%) or specifically acting (2.7%), while the majority were non-assigned (61%). Overall environmental persistence, bioaccumulation and long-range transport potential were evaluated using structure-activity relationships and a multimedia fugacity-based model. A surprisingly high proportion of compounds (20%), mainly aromatic and halogenated, had a very high estimated persistence (>195 d). The proportion of compounds with a very high estimated bioconcentration or bioaccumulation factor (>5000) was substantially less (6.9%). Finally, a list was compiled of those compounds within the applicability domain of the models used, meeting both persistence and bioaccumulation criteria, and with a long-range transport potential comparable to PCB. This list of 68 potential persistent organic pollutants contained many well-known compounds (all halogenated), but notably also five fluorinated compounds that were not included in the EINECS inventory. This study demonstrates the usability of in silico tools for identification of potentially environmentally hazardous chemicals.

  8. Seasonal variations of leaf and canopy properties tracked by ground-based NDVI imagery in a temperate forest.

    Science.gov (United States)

    Yang, Hualei; Yang, Xi; Heskel, Mary; Sun, Shucun; Tang, Jianwu

    2017-04-28

    Changes in plant phenology affect the carbon flux of terrestrial forest ecosystems due to the link between the growing season length and vegetation productivity. Digital camera imagery, which can be acquired frequently, has been used to monitor seasonal and annual changes in forest canopy phenology and track critical phenological events. However, quantitative assessment of the structural and biochemical controls of the phenological patterns in camera images has rarely been done. In this study, we used an NDVI (Normalized Difference Vegetation Index) camera to monitor daily variations of vegetation reflectance at visible and near-infrared (NIR) bands with high spatial and temporal resolutions, and found that the infrared camera based NDVI (camera-NDVI) agreed well with the leaf expansion process that was measured by independent manual observations at Harvard Forest, Massachusetts, USA. We also measured the seasonality of canopy structural (leaf area index, LAI) and biochemical properties (leaf chlorophyll and nitrogen content). We found significant linear relationships between camera-NDVI and leaf chlorophyll concentration, and between camera-NDVI and leaf nitrogen content, though weaker relationships between camera-NDVI and LAI. Therefore, we recommend ground-based camera-NDVI as a powerful tool for long-term, near surface observations to monitor canopy development and to estimate leaf chlorophyll, nitrogen status, and LAI.

  9. Controlling Botrytis elliptica Leaf Blight on Hybrid Lilies through the Application of Convergent Chemical X-ray Irradiation

    Directory of Open Access Journals (Sweden)

    Sung-Jun Hong

    2016-04-01

    Full Text Available X-ray irradiation with convergent chemicals such as nano-silver particles or sodium dichloroisocyanurate (NaDCC has been used to control leaf blight on cut lilies. The oriental hybrid lily cultivars Siberia, Le Reve, and Sorbonne were irradiated five times by 200 Gy of X-rays in 2014. In 2015, Siberia and Sorbonne were irradiated three times by 150 Gy of X-rays. After artificial infection with Botrytis elliptica on the leaves and petals of cut lilies, this study used convergent chemical X-ray irradiation of 200 Gy or 150 Gy. Leaf and petal blight was measured in terms of incidence and severity at 8 days after infection using total 552 cuttings. Results indicate that the treatments of X-ray irradiation and NaDCC in 2014 and 2015 slightly decreased the severity of petal blight on Siberia and Sorbonne. However, the results were not significant and severity did not decrease as NaDCC concentration increased. Vase-life was observed separately after X-ray irradiation of 270 cut lilies in 2014 and 108 cut lilies in 2015. Chlorophyll content was not affected by either 200 Gy or 150 Gy of X-rays. The number of days of fully opened flowers at Siberia of 150 Gy and Le Revu of 200 Gy increased by 1–2 days. In addition, the relative fresh weights of the X-rayed flowers were 10% drier than the non-irradiated controls. Overall, leaf blight control by X-ray was inferior to the control by gamma rays, and petal color was bleached in Sorbonne and Le Reve cvs. by 150 Gy of X-rays.

  10. Disease variation and chemical control of Ramularia leaf spot in sugar beet

    DEFF Research Database (Denmark)

    Thach, Tine; Munk, Lisa; Hansen, Anne Lisbet

    2013-01-01

    Data from 1999 to 2009 on Ramularia leaf spot caused by Ramularia beticola in sugar beet showed that it was a serious disease in sugar beet in 5 out of 11 seasons. The severity and significance of the disease was found to vary depending on events with precipitation, particularly in two specific...... weeks in July and September. Several fungicides were found to give effective control, and positive net yield responses were found in 9 out of 11 seasons. The average sugar yield response varied in individual years between 0.7 and 2.2 t ha−1. High levels of control of Ramularia leaf spot was obtained...... in field trials, a semi-field trial and an in vitro test using the compounds pyraclostrobin, epoxiconazole, difenoconazole and propiconazole. Dose response trials with epoxiconazole from two seasons showed both reduced efficacy and yield responses from low doses. They also proved that the optimal input...

  11. Effect of Different Parts (Leaf, Stem and Stalk) and Seasons (Summer and Winter) on the Chemical Compositions and Antioxidant Activity of Moringa oleifera

    OpenAIRE

    Cheng-Ming Chang; Min-Lang Tsai; Sue-Ming Kang; Ming-Chih Shih

    2011-01-01

    Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stron...

  12. Chemical Characterization and in Vitro Cytotoxicity on Squamous Cell Carcinoma Cells of Carica Papaya Leaf Extracts

    Directory of Open Access Journals (Sweden)

    Thao T. Nguyen

    2015-12-01

    Full Text Available In traditional medicine, Carica papaya leaf has been used for a wide range of therapeutic applications including skin diseases and cancer. In this study, we investigated the in vitro cytotoxicity of aqueous and ethanolic extracts of Carica papaya leaves on the human oral squamous cell carcinoma SCC25 cell line in parallel with non-cancerous human keratinocyte HaCaT cells. Two out of four extracts showed a significantly selective effect towards the cancer cells and were found to contain high levels of phenolic and flavonoid compounds. The chromatographic and mass spectrometric profiles of the extracts obtained with Ultra High Performance Liquid Chromatography-Quadrupole Time of Flight-Mass Spectrometry were used to tentatively identify the bioactive compounds using comparative analysis. The principal compounds identified were flavonoids or flavonoid glycosides, particularly compounds from the kaempferol and quercetin families, of which several have previously been reported to possess anticancer activities. These results confirm that papaya leaf is a potential source of anticancer compounds and warrant further scientific investigation to validate the traditional use of papaya leaf to treat cancer.

  13. Chemical Characterization and in Vitro Cytotoxicity on Squamous Cell Carcinoma Cells of Carica papaya Leaf Extracts.

    Science.gov (United States)

    Nguyen, Thao T; Parat, Marie-Odile; Hodson, Mark P; Pan, Jenny; Shaw, Paul N; Hewavitharana, Amitha K

    2015-12-24

    In traditional medicine, Carica papaya leaf has been used for a wide range of therapeutic applications including skin diseases and cancer. In this study, we investigated the in vitro cytotoxicity of aqueous and ethanolic extracts of Carica papaya leaves on the human oral squamous cell carcinoma SCC25 cell line in parallel with non-cancerous human keratinocyte HaCaT cells. Two out of four extracts showed a significantly selective effect towards the cancer cells and were found to contain high levels of phenolic and flavonoid compounds. The chromatographic and mass spectrometric profiles of the extracts obtained with Ultra High Performance Liquid Chromatography-Quadrupole Time of Flight-Mass Spectrometry were used to tentatively identify the bioactive compounds using comparative analysis. The principal compounds identified were flavonoids or flavonoid glycosides, particularly compounds from the kaempferol and quercetin families, of which several have previously been reported to possess anticancer activities. These results confirm that papaya leaf is a potential source of anticancer compounds and warrant further scientific investigation to validate the traditional use of papaya leaf to treat cancer.

  14. A comparative pharmacognostical and preliminary physico-chemical analysis of stem and leaf of Bacopa monnieri (L.) Pennel and Bacopa floribunda (R.BR.) Wettst.

    Science.gov (United States)

    Gubbannavar, Jyoti S; Chandola, H M; Harisha, C R; Khanpara, Komal; Shukla, V J

    2013-01-01

    Brahmi is a well-known herbal drug having an effect on brain as a memory enhancer. Bacopa monnieri (L.) Pennel and Bacopa floribunda (R.Br.) Wettst are both marketed in the name of Brahmi. The present study differentiates Bacopa monnieri and Bacopa floribunda in morphology, transverse section (T.S.) of root and leaf, powder microscopy, and chemical constituents. Morphological characters show color difference in flower, stem and leaf and differences in microscopic study, organoleptic study, and powder characteristics. Morphologically, Bacopa monnieri leaf is fleshy and more succulent than Bacopa floribunda leaf. There is also a difference in the interval of the stem internodes of the two. Physico-chemical analysis revealed presence of 26% bacoside A in Bacopa floribunda leaf and 27% in Bacopa floribunda stem, which is higher than the bacoside A content in leaf (22%) and stem (18%) of Bacopa monnieri. However due to the hemolytic action of bacoside A, which is the toxic effect of the chemical constituent, it seems likely that Bacopa monnieri is more popular in regular use than Bacopa floribunda.

  15. Antitumour properties of the leaf essential oil of Xylopia frutescens Aubl. (Annonaceae).

    Science.gov (United States)

    Ferraz, Rosana P C; Cardoso, Gabriella M B; da Silva, Thanany B; Fontes, José Eraldo do N; Prata, Ana Paula do N; Carvalho, Adriana A; Moraes, Manoel O; Pessoa, Claudia; Costa, Emmanoel V; Bezerra, Daniel P

    2013-11-01

    The aim of this study was to investigate the chemical composition and anticancer effect of the leaf essential oil of Xylopia frutescens in experimental models. The chemical composition of the essential oil was analysed by GC/FID and GC/MS. In vitro cytotoxic activity of the essential oil was determined on cultured tumour cells. In vivo antitumour activity was assessed in Sarcoma 180-bearing mice. The major compounds identified were (E)-caryophyllene (31.48%), bicyclogermacrene (15.13%), germacrene D (9.66%), δ-cadinene (5.44%), viridiflorene (5.09%) and α-copaene (4.35%). In vitro study of the essential oil displayed cytotoxicity on tumour cell lines and showed IC50 values ranging from 24.6 to 40.0 μg/ml for the NCI-H358M and PC-3M cell lines, respectively. In the in vivo antitumour study, tumour growth inhibition rates were 31.0-37.5%. In summary, the essential oil was dominated by sesquiterpene constituents and has some interesting anticancer activity.

  16. Remote Estimation of Leaf and Canopy Water Content in Winter Wheat with Different Vertical Distribution of Water-Related Properties

    Directory of Open Access Journals (Sweden)

    Shishi Liu

    2015-04-01

    Full Text Available This study analyzed the vertical distribution of gravimetric water content (GWC, relative water content (RWC, and equivalent water thickness (EWT in winter wheat during heading and early ripening stages, and evaluated the position of leaf number at which Vegetation Indexes (VIs can best retrieve canopy water-related properties of winter wheat. Results demonstrated that the vertical distribution of these properties followed a near-bell-shaped curve with the highest values at the intermediate leaf position. GWC of the top three or four leaves during the heading stage and the top two or three leaves during the early ripening stage can represent the GWC of the whole canopy, but the RWC and EWT of the whole canopy should be calculated based on the top four leaves. At leaf level, the analysis demonstrated strong relationships between EWT and VIs for the top leaf layer, but for GWCD, GWCF, and RWC, the strongest relationships with VIs were found in the intermediate leaf layers. At canopy level, VIs provided the most accurate estimation of GWCfor the top three or four leaves. Water absorption-based VIs could estimate canopy EWT of winter wheat for the top four leaves, but the suitable bands sensitive to water absorptions should be carefully selected for the studied species.

  17. Minimizing measurement uncertainties of coniferous needle-leaf optical properties, part II: experimental set-up and error analysis

    NARCIS (Netherlands)

    Yanez Rausell, L.; Malenovsky, Z.; Clevers, J.G.P.W.; Schaepman, M.E.

    2014-01-01

    We present uncertainties associated with the measurement of coniferous needle-leaf optical properties (OPs) with an integrating sphere using an optimized gap-fraction (GF) correction method, where GF refers to the air gaps appearing between the needles of a measured sample. We used an optically stab

  18. Chemical composition of leaf and seed essential oil of Coriandrum sativum L. from Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Nazrul Islam Bhuiyan, Jaripa Begum and Mahbuba Sultana

    2009-12-01

    Full Text Available The essential oils from leaves and fruits of Coriandrum sativum L. were analyzed by gas chromatography mass spectroscopy (GC-MS. The leaf oil contained 44 compounds mostly of aromatic acids containing 2-decenoic acid (30.8%, E-11-tetradecenoic acid (13.4%, capric acid (12.7%, undecyl alcohol (6.4%, tridecanoic acid (5.5% and undecanoic acid (7.1% as major constituents. The seed oil contains 53 compounds where the major compounds are linalool (37.7%, geranyl acetate (17.6% and γ-terpinene (14.4%. The compositions of both oils varied qualitatively and quantitatively.

  19. Chemical composition of leaf and seed essential oil of Coriandrum sativum L. from Bangladesh

    Directory of Open Access Journals (Sweden)

    Mohammad Nazrul Islam Bhuiyan

    2009-06-01

    Full Text Available The essential oils from leaves and fruits of Coriandrum sativum L. were analyzed by gas chromatography mass spectroscopy (GC-MS. The leaf oil contained 44 compounds mostly of aromatic acids containing 2-decenoic acid (30.8%, E-11-tetradecenoic acid (13.4%, capric acid (12.7%, undecyl alcohol (6.4%, tridecanoic acid (5.5% and undecanoic acid (7.1% as major constituents. The seed oil contains 53 compounds where the major compounds are linalool (37.7%, geranyl acetate (17.6% and γ-terpinene(14.4%. The compositions of both oils varied qualitatively and quantitatively.

  20. Chemical disguise of myrmecophilous cockroaches and its implications for understanding nestmate recognition mechanisms in leaf-cutting ants.

    Science.gov (United States)

    Nehring, Volker; Dani, Francesca R; Calamai, Luca; Turillazzi, Stefano; Bohn, Horst; Klass, Klaus-Dieter; d'Ettorre, Patrizia

    2016-08-05

    Cockroaches of the genus Attaphila regularly occur in leaf-cutting ant colonies. The ants farm a fungus that the cockroaches also appear to feed on. Cockroaches disperse between colonies horizontally (via foraging trails) and vertically (attached to queens on their mating flights). We analysed the chemical strategies used by the cockroaches to integrate into colonies of Atta colombica and Acromyrmex octospinosus. Analysing cockroaches from nests of two host species further allowed us to test the hypothesis that nestmate recognition is based on an asymmetric mechanism. Specifically, we test the U-present nestmate recognition model, which assumes that detection of undesirable cues (non-nestmate specific substances) leads to strong rejection of the cue-bearers, while absence of desirable cues (nestmate-specific substances) does not necessarily trigger aggression. We found that nests of Atta and Acromyrmex contained cockroaches of two different and not yet described Attaphila species. The cockroaches share the cuticular chemical substances of their specific host species and copy their host nest's colony-specific cuticular profile. Indeed, the cockroaches are accepted by nestmate but attacked by non-nestmate ant workers. Cockroaches from Acromyrmex colonies bear a lower concentration of cuticular substances and are less likely to be attacked by non-nestmate ants than cockroaches from Atta colonies. Nest-specific recognition of Attaphila cockroaches by host workers in combination with nest-specific cuticular chemical profiles suggest that the cockroaches mimic their host's recognition labels, either by synthesizing nest-specific substances or by substance transfer from ants. Our finding that the cockroach species with lower concentration of cuticular substances receives less aggression by both host species fully supports the U-present nestmate recognition model. Leaf-cutting ant nestmate recognition is thus asymmetric, responding more strongly to differences than to

  1. Thermodynamic and transport properties of gaseous tetrafluoromethane in chemical equilibrium

    Science.gov (United States)

    Hunt, J. L.; Boney, L. R.

    1973-01-01

    Equations and in computer code are presented for the thermodynamic and transport properties of gaseous, undissociated tetrafluoromethane (CF4) in chemical equilibrium. The computer code calculates the thermodynamic and transport properties of CF4 when given any two of five thermodynamic variables (entropy, temperature, volume, pressure, and enthalpy). Equilibrium thermodynamic and transport property data are tabulated and pressure-enthalpy diagrams are presented.

  2. Phytotoxic effects and chemical analysis of leaf extracts from three Phytolaccaceae species in South Korea.

    Science.gov (United States)

    Kim, Yong Ok; Johnson, Jon D; Lee, Eun Ju

    2005-05-01

    We analyzed phenolic compounds and other elements in leaf extracts and compared morphology of three species of the Phytolaccaceae family found in South Korea. To test allelochemical effects of the three Phytolacca species, we also examined seed germination and dry weight of seedlings of Lactuca indica and Sonchus oleraceus treated with leaf extracts. The concentrations of total phenolic compounds were exotic Phytolacca esculenta (3.9 mg/l), native Phytolacca insularis (4.4 mg/l), and exotic Phytolacca americana (10.2 mg/l). There was no significant difference in concentrations between P. esculenta and P. insularis, but the concentration of total phenolics in P. americana was two times higher than either P. esculenta or P. insularis. Analysis of aqueous extracts by HPLC showed seven phenolic compounds (gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, m-hydroxybenzoic acid, p-coumaric acid, and cinnamic acid). Total phenolics in P. americana were eight to 16 times higher than either P. esculenta or P. insularis, respectively. P. americana inhibited seed germination and dry weight of the two assay species. The phytotoxic effects of the two Phytolacca species were different, despite the fact that P. esculenta and P. insularis had similar levels of total phenolic compounds. We also found that P. americana had invaded Ullung Island, which suggested that P. americana had excellent adaptability to the environment. The three species of Phytolaccaceae in South Korea can be distinguished by their different allelopathic potentials and morphologies.

  3. A comparison of tensile properties of polyester composites reinforced with pineapple leaf fiber and pineapple peduncle fiber

    Science.gov (United States)

    Juraidi, J. M.; Shuhairul, N.; Syed Azuan, S. A.; Intan Saffinaz Anuar, Noor

    2013-12-01

    Pineapple fiber which is rich in cellulose, relatively inexpensive, and abundantly available has the potential for polymer reinforcement. This research presents a study of the tensile properties of pineapple leaf fiber and pineapple peduncle fiber reinforced polyester composites. Composites were fabricated using leaf fiber and peduncle fiber with varying fiber length and fiber loading. Both fibers were mixed with polyester composites the various fiber volume fractions of 4, 8 and 12% and with three different fiber lengths of 10, 20 and 30 mm. The composites panels were fabricated using hand lay-out technique. The tensile test was carried out in accordance to ASTM D638. The result showed that pineapple peduncle fiber with 4% fiber volume fraction and fiber length of 30 mm give highest tensile properties. From the overall results, pineapple peduncle fiber shown the higher tensile properties compared to pineapple leaf fiber. It is found that by increasing the fiber volume fraction the tensile properties has significantly decreased but by increasing the fiber length, the tensile properties will be increased proportionally. Minitab software is used to perform the two-way ANOVA analysis to measure the significant. From the analysis done, there is a significant effect of fiber volume fraction and fiber length on the tensile properties.

  4. Mosquitocidal properties of Solanum trilobatum L. (Solanaceae) leaf extracts against three important human vector mosquitoes (Diptera: Culicidae).

    Science.gov (United States)

    Premalatha, Selvaraj; Elumalai, Kuppusamy; Jeyasankar, Alagarmalai

    2013-11-01

    To determine the larvicidal and pupicidal activites of Solanum trilobatum (S. trilobatum) leaf extracts against Aedes aegypti (Ae. aegypti), Culex quinquefasciatus (Cx. quinquefasciatus) and Anopheles stephensi (An. stephensi). The larvicidal and pupucidal was determined at five different concentrations of 50, 100, 150, 200 and 250 ppm. Percentage of larval mortality was assessed after 48 h. Methanol extracts of S. trilobatum was found to be more susceptible against the larvae of Ae. aegypti, Cx. quinquefasciatus and An. stephensi at 250 ppm with a LC50 value of 125.43, 127.77 and 116.64 ppm respectively. Leaf methanol extracts of S. trilobatum also exhibited pupicidal and adult emergence properties. These results suggested that the leaf extracts of S. trilobatum showed potential to be used as an ideal ecofriendly approach for the control of the Ae. Aegypti, Cx. quinquefasciatus and An. stephensi. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  5. Evaluation of Antimicrobial properties and nutritional potentials of Moringa oleifera Lam.leaf in South-Western Nigeria

    Directory of Open Access Journals (Sweden)

    Oluduro, A. O.

    2012-06-01

    Full Text Available Aims: The antimicrobial activities of the leaf extract of Moringa oleifera on certain enteropathogenic and orthopaedics’wounds bacteria and fungi were investigated. Its phytochemical constituents and nutritional potentials were as well assessed. Methodology and results: The antimicrobial activities of the leaf extracts were evaluated using paper disc diffusion method. All the leaf extracts showed little inhibitory effect on the enteropathogens, whereas aqueous and methanolic extracts showed appreciable inhibitory effects on the orthopaedic’s wounds bacteria at 30 mg/mL. Ethanolic extract did not show any zone of growth inhibition on the wound bacteria. All the fungal organisms except Aspergillus flavus wereresistant to both aqueous and methanolic extracts of the leaf, meanwhile Ethanolic extract showed appreciable inhibitory effect on Tricophyton mentagrophyte, Pullarium sp, Aspergilus flavus and Penicillium sp. Minimum inhibitory concentration was 20 mg/mL on all the enteropathogens and ranged from 3.75 to 30leaf andcontained appreciable quantity of calcium, magnesium, iron and 45.4 % carbohydrate, 16.2 % protein and 9.68 % fibre. Conclusion, significance and impact of study: The study showed that Moringa oleifera leaves possess inhibitory properties thus can serve as an alternative therapy for wounds and certain fungal infections and also a good source of nutrient supplements.

  6. Phytochemical, Physico-chemical & Spectroscopic Characteristics of Ethanolic Extract of Leaf, Stem and Flower bud of Hibiscus hispidissimus Griffith

    Directory of Open Access Journals (Sweden)

    Thamizh Selvam N

    2015-08-01

    Full Text Available The plant Hibiscus hispidissimus belongs to the family Malvaceae (Mallow family. The plant has wide range of medicinal uses. Considering the ethno medicinal value of Hibiscus hispidissimus, the present work has been taken up to document the physico-chemical composition, phytochemical details and spectrophotometric characteristics of the plant. The work has been carried out on ethanolic extract of leaf, stem and flower bud of H. hispidissimus. Phytochemical analysis showed the presence of saponis, tannins, glycosides, diterpenes and quinones. Spectroscopic characteristics were analyzed and found to have wide range of compounds including steroids, alkaloids, pigments like chlorophyll a and b, phenolic compounds mainly gallic acid, flavanoids like anthocyanins, flavanols, flvanones and isoflavones.

  7. Physico-chemical properties and energy potential of wood wastes ...

    African Journals Online (AJOL)

    Physico-chemical properties and energy potential of wood wastes from ... Journal Home > Vol 36, No 2 (2017) > ... The results are indications that the wood wastes are suitable as feedstock for renewable energy generation with little or no ...

  8. Physio-chemical, mineral composition and antioxidant properties of ...

    African Journals Online (AJOL)

    Physio-chemical, mineral composition and antioxidant properties of Roselle ... The roselle extract has a unique red colour, good flavour, low sugar and high acidic ... human body from several diseases attributed to the reactions of free radicals.

  9. Terrestrial gamma dose rates and physical-chemical properties of ...

    African Journals Online (AJOL)

    Terrestrial gamma dose rates and physical-chemical properties of farm soils ... African Journal of Environmental Science and Technology ... left a legacy derelict landscapes and impoverished agricultural farm lands in the Jos, Plateau Nigeria.

  10. chemical properties of soil in rivers state, nigeria *ch

    African Journals Online (AJOL)

    Osondu

    chemical properties and the spatial extent ... the core and decreased with increasing distance from the core. ... Key words: Charcoal, Soil, Change index, Niger Delta, Nigeria ..... practices. References. Agbenin, J.O. (1995), Laboratory manual for Soil.

  11. physical and chemical properties of some selected rice varieties in ...

    African Journals Online (AJOL)

    User

    Physical and chemical properties of nine rice varieties grown and processed in Ebonyi State were studied. ... adaptation traits for each ecology (Sanni et al., 2005). Abakaliki in Ebonyi State ..... Some Quality Factors of Raw and Processed rice.

  12. Leaf biomechanical properties in Arabidopsis thaliana polysaccharide mutants affect drought survival.

    Science.gov (United States)

    Balsamo, Ronald; Boak, Merewyn; Nagle, Kayla; Peethambaran, Bela; Layton, Bradley

    2015-11-26

    Individual sugars are the building blocks of cell wall polysaccharides, which in turn comprise a plant׳s overall architectural structure. But which sugars play the most prominent role in maintaining a plant׳s mechanical stability during large cellular deformations induced by drought? We investigated the individual contributions of several genes that are involved in the synthesis of monosaccharides which are important for cell wall structure. We then measured drought tolerance and mechanical integrity during simulated drought in Arabidopsis thaliana. To assess mechanical properties, we designed a small-scale tensile tester for measuring failure strain, ultimate tensile stress, work to failure, toughness, and elastic modulus of 6-week-old leaves in both hydrated and drought-simulated states. Col-0 mutants used in this study include those deficient in lignin, cellulose, components of hemicellulose such as xylose and fucose, the pectic components arabinose and rhamnose, as well as mutants with enhanced arabinose and total pectin content. We found that drought tolerance is correlated to the mechanical and architectural stability of leaves as they experience dehydration. Of the mutants, S096418 with mutations for reduced xylose and galactose was the least drought tolerant, while the arabinose-altered CS8578 mutants were the least affected by water loss. There were also notable correlations between drought tolerance and mechanical properties in the diminished rhamnose mutant, CS8575 and the dehydrogenase-disrupted S120106. Our findings suggest that components of hemicellulose and pectins affect leaf biomechanical properties and may play an important role in the ability of this model system to survive drought.

  13. β-Amyloid pathogenesis: Chemical properties versus cellular levels

    DEFF Research Database (Denmark)

    Tiwari, Manish Kumar; Kepp, Kasper Planeta

    2016-01-01

    , or aggregation propensities. Cytotoxicity correlates inversely with total Aβ42 (R2=0.65, P =.016) and Aβ42/Aβ40 ratios (R2=0.76, P=.005), i.e., chemical properties that increase Aβ42 also reduce toxicity. The complexity and heterogeneity of data reveal the need to understand these phenotypes better, e.......g., by focusing on the chemical properties of the involved Aβ species....

  14. determination of physio determination of physio-chemical properties ...

    African Journals Online (AJOL)

    eobe

    The objectives were to determine the physical, chemical ... seed oil exhibited good chemical properties for biodiesel production with a viscosity of 46.58mpa/s at 30oC,. Free Fatty Acid (FFA) ... production than animal fats and used/blended oils.

  15. Allelopathic activity and chemical constituents of walnut (Juglans regia) leaf litter in walnut-winter vegetable agroforestry system.

    Science.gov (United States)

    Wang, Qian; Xu, Zheng; Hu, Tingxing; Rehman, Hafeez Ur; Chen, Hong; Li, Zhongbin; Ding, Bo; Hu, Hongling

    2014-01-01

    Walnut agroforestry systems have many ecological and economic benefits when intercropped with cool-season species. However, decomposing leaf litter is one of the main sources of allelochemicals in such systems. In this study, lettuce (Lactuca sativa var. angustata) was grown in the soil incorporated with walnut leaf litter to assess its allelopathic activity. Lettuce growth and physiological processes were inhibited by walnut leaf litter, especially during early growth stage (1-2 euphylla period) or with large amount of litter addition. The plants treated by small amount of leaf litter recovered their growth afterwards, while the inhibition for 180 g leaf litter persisted until harvest. Twenty-eight compounds were identified in the leaf litter, and several of them were reported to be phytotoxic, which may be responsible for the stress induced by walnut leaf litter. Thus, for highest economic value of vegetables such as lettuce, excessive incorporation of leaf litter should be discouraged.

  16. The study of mechanical properties of pineapple leaf fibre reinforced tapioca based bioplastic resin composite

    Directory of Open Access Journals (Sweden)

    Mathivanan D.

    2016-01-01

    Full Text Available Natural fibre reinforced composite has brought the material engineering to a high new level of research. Natural fibres are compatible with matrices like polypropylene and can be used as reinforcement material to reduce the composition of plastic in a material. Natural fibres such as kenaf, pineapple leaf, and coir already found its importance in reducing the dependence of petroleum based products. However the biodegradability of the product at the end of the intended lifespan is still questionable. This has led many researches to look for a suitable replacement for synthetic fibres and achieve better adhesion between fibre and matrix. In this study, fiber and matrix which are hydrophilic in nature was used and the mixture was extruded and hot compressed to acquire better mechanical properties. The specimens were fabricated and tested according to ASTM D638. The 30% composition illustrates the best average modulus value among other composition and from this result it can be concluded that the increase of PALF fibre in TBR composite increases the modulus strength of the composite.

  17. Larvicidal and pupicidal properties of Acalypha alnifolia Klein ex Willd. (Euphorbiaceae) leaf extract and the microbial insecticide Metarhizium anisopliae (Metsch.) against lymphatic filarial vector, Culex quinquefasciatus..

    Science.gov (United States)

    This study was made to determine the mosquitocidal properties of Acalypha alnifolia leaf extract combined with the use of Metarizhium anisopliae spores for control of the lymphatic filariasis vector Culex quinquefasciatus. The methanolic leaf extract showed larvicidal and pupicidal effects after 24...

  18. Larvicidal and pupicidal properties of Acalypha alnifolia Klein ex willd.(Euphorbiaceae) leaf extract and the microbial insecticide Metarhizium anisopliae (Metsch.) against lymphatic filarial vector, Culex quinquefasciatus Sa

    Science.gov (United States)

    This study was made to determine the mosquitocidal properties of Acalypha alnifolia leaf extract combined with the use of Metarizhium anisopliae spores for control of the lymphatic filariasis vector Culex quinquefasciatus. The methanolic leaf extract showed larvicidal and pupicidal effects after 24...

  19. Study on scattering properties of tissues with hyperosmotic chemical agents

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optical properties of biological tissue are variable due to the changes of micro-structures and scattering constituents after hyperosmotic chemical agents permeates into tissue. The changes of optical properties of biological tissue are due to the refractive indices matching between the scatterers with high refractive index and the ground substances, which reduce scattering of tissue. The main reasons are that permeated semipermeable chemical agents with higher refractive index than the ground substances of tissuemakes the refractive index of ground substances of tissue higher by the enhancement of the permeated concentration. We studied on the collimated transmittance changes of light penetrating biological tissue after the hyperosmotic chemical agents administrates with different concentration.

  20. Chemical composition, and anti-proliferative and anti-inflammatory effects of the leaf and wholeplant samples of diploid and tetraploid gynostemma pentaphyllum

    Science.gov (United States)

    Leaf and whole-plant samples of the diploid and tetraploid Gynostemma pentaphyllum (GP)were investigated and compared for their chemical compositions, and their potential anti-proliferative and anti-inflammatory effects. The highest levels of total flavonoids and phenolics were observed in the diplo...

  1. Outgassing Properties of Chemically Polished Titanium Materials

    Science.gov (United States)

    Kurisu, Hiroki; Kimoto, Gou; Fujii, Hiroaki; Tanaka, Kazuhiko; Yamamoto, Setsuo; Matsuura, Mitsuru; Ishizawa, Katsunobu; Nomura, Takeru; Murashige, Nobuyuki

    We developed a chemical polishing (CP) for titanium materials applicable to ultrahigh vacuum (UHV) and extremely high vacuum (XHV) systems. The surface roughness, Ra, of the chemically polished titanium is obtained to be 25 nm by the atomic force microscopy measurement. This value is smaller than those of the base metal (BM) and the buff-polished (BP) samples. The thickness of the surface oxide layer of CP sample is estimated to be 7 nm by the cross section of transmission electron micrograph. Amount of desorption gas of CP sample obtained by the thermal desorption measurement is smaller than those of BM and BP sample, and is the same as that of the mechanochemically polished (MCP) sample. The outgassing rate of CP sample after baking at 150°C×20 h is obtained to be 7×10-13 Pa•m•s-1. This value is lower than that of standard vacuum materials by two orders of magnitude after the ordinary baking.

  2. Physical and Chemical Properties of Meteoric Smoke

    Science.gov (United States)

    Plane, J. M.; Saunders, R. E.

    2005-12-01

    Somewhere between 10 and 100 tonnes (the current range of estimates) of interplanetary dust enters the earth's atmosphere each day. At least 60 percent of this ablates completely into atoms and ions, mostly between 70 and 110 km. This paper is concerned with the subsequent fate of the ablated metals and silicon. These species form a variety of oxides and hydroxides below 90 km, and it is widely believed that these species condense into nanometer-sized dust particles, known as "meteoric smoke". Here we will report laboratory experiments to simulate the production of meteoric smoke particles. Several chemical systems were investigated using a photochemical reactor: pure iron, iron-oxygen, silicon-oxygen and mixed iron-silicon-oxygen nano-particles. The particles were analysed for size distribution (diameter greater than 3 nm), chemical and physical structure and optical extinction. The kinetics of particle growth through condensation and coagulation were also measured in a novel aerosol flow tube. The results are used to refine aerosol growth models, and then to speculate on the likely form and size distribution of meteoric smoke in the mesosphere. Finally, we will consider how changes in the interplanetary dust flux could have affected the evolution of the earth's atmosphere.

  3. PHOSPHOGYPSUM AND VINASSE APPLICATION: SOIL CHEMICAL PROPERTIES AND ALFALFA PRODUCTIVITY AND NUTRITIONAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    RONALDO DO NASCIMENTO

    2017-01-01

    Full Text Available The objective of this work was to evaluate the effects of the application of phosphogypsum and vinasse on soil chemical properties and productivity and nutritional characteristics of alfalfa (Medicago sativa. The experiment was conducted in a randomized block design, using a 3×5 factorial arrangement, with three vinasse rates (0, 150 and 300 m3 ha-1 and five phosphogypsum rates (0, 3, 6, 9 and 12 Mg ha-1. The alfalfa chemical composition and shoot dry matter (SDW and soil chemical properties (in the layers 0.0-0.2 and 0.21-0.4 m were evaluated. The vinasse rates increased the soil potassium contents, while the phosphogypsum rates promoted linear increases in soil calcium and sulfur contents. The base saturation was increased and the magnesium content showed a quadratic response on the layer 0.21-0.4 m with the increase in phosphogypsum rates. The calcium, magnesium and phosphorus contents in the alfalfa leaves were lower with vinasse application. The phosphogypsum rates promoted linear increases in alfalfa SDW. Vinasse rated 150 m3 ha-1 was been enough to SDW increase. Calcium and magnesium contents in the leaves fitted a quadratic model, with maximum calcium content in the phosphogypsum rate of 9.5 Mg ha-1 and the minimum magnesium content in the phosphogypsum rate of 8.7 Mg ha-1. The leaf sulfur contents in all vinasse rates and leaf potassium contents in the highest vinasse rate showed maximum accumulation at near 9 Mg ha-1 of phosphogypsum.

  4. Chemical composition of lucerne leaf extract (EFL) and its applications as a phytobiotic in human nutrition.

    Science.gov (United States)

    Gaweł, Eliza

    2012-01-01

    Lucerne, a valuable plant grown mainly for animal feed, is rich in protein, minerals (Ca, Cu, Fe, Mg, Mn, P, Zn, Si), vitamins (A, B, C, D, E, K, U), phytochemical substances (carotene, chlorophyll, coumarins, isoflavones, alkaloids, saponins), contains secondary metabolites of plants (phytoestrogens: isoflavones and coumestrol), and antinutritional components (phytates, L-canavanine, saponins). It may be used as a dietary supplement in human nutrition. The proteins found in lucerne are comprised of numerous exogenous and semi-exogenous amino acids which are desirable for human body. Extract from the leaves of alfalfa (EFL - l'Extrait Foliaire de Luzerne) practically does not contain mycotoxins and pesticide pollutants. It is a completely natural product, safe even in a long-term supplementation. Extract from the leaves of alfalfa has a positive, multidirectional impact on the human body. It increases the level of estrogen, prevents atherosclerosis, helps blood circulation and strenghtens immunity, protects against the development of dangerous diseases of the digestive tract, combats anemia and many other health ailments. The results of preclinical studies indicate that alfalfa leaf extract enriched with vitamin C (EFL) can be a dietary supplement supporting the human body in fighting malnutrition, ischemic diseases, and various disorders of digestive tract. It also strengthens and enhances immunity.

  5. Chemical composition of lucerne leaf extract (EFL and its applications as a phytobiotic in human nutrition

    Directory of Open Access Journals (Sweden)

    Eliza Gaweł

    2012-09-01

    Full Text Available   Lucerne, a valuable plant grown mainly for animal feed, is rich in protein, minerals (Ca, Cu, Fe, Mg, Mn, P, Zn, Si, vitamins (A, B, C, D, E, K, U, phytochemical substances (carotene, chlorophyll, coumarins, isoflavones, alkaloids, saponins, contains secondary metabolites of plants (phytoestrogens: isoflavones and coumestrol, and antinutritional components (phytates, L-canavanine, saponins. It may be used as a dietary supplement in human nutrition. The proteins found in lucerne are comprised of numerous exogenous and semi-exogenous amino acids which are desirable for human body. Extract from the leaves of alfalfa (EFL – l’Extrait Foliaire de Luzerne practically does not contain mycotoxins and pesticide pollutants. It is a completely natural product, safe even in a long-term supplementation. Extract from the leaves of alfalfa has a positive, multidirectional impact on the human body. It increases the level of estrogen, prevents atherosclerosis, helps blood circulation and strenghtens immunity, protects against the development of dangerous diseases of the digestive tract, combats anemia and many other health ailments. The results of preclinical studies indicate that alfalfa leaf extract enriched with vitamin C (EFL can be a dietary supplement supporting the human body in fighting malnutrition, ischemic diseases, and various disorders of digestive tract. It also strengthens and enhances immunity.  

  6. SOIL CHEMICAL ATTRIBUTES AND LEAF NUTRIENTS OF ‘PACOVAN’ BANANA UNDER TWO COVER CROPS

    Directory of Open Access Journals (Sweden)

    JOSÉ EGÍDIO FLORI

    2016-01-01

    Full Text Available Banana is one of the most consumed fruits in the world, which is grown in most tropical countries. The objective of this work was to evaluate the main attributes of soil fertility in a banana crop under two cover crops and two root development locations. The work was conducted in Curaçá, BA, Brazil, between October 2011 and May 2013, using a randomized block design in split plot with five repetitions. Two cover crops were assessed in the plots, the cover 1 consisting of Pueraria phaseoloides, and the cover 2 consisting of a crop mix with Sorghum bicolor, Ricinus communis L., Canavalia ensiformis, Mucuna aterrima and Zea mays, and two soil sampling locations in the subplots, between plants in the banana rows (location 1 and between the banana rows (location 2. There were significant and independent effects for the cover crop and sampling location factors for the variables organic matter, Ca and P, and significant effects for the interaction between cover crops and sampling locations for the variables potassium, magnesium and total exchangeable bases. The cover crop mix and the between-row location presented the highest organic matter content. Potassium was the nutrient with the highest negative variation from the initial content and its leaf content was below the reference value, however not reducing the crop yield. The banana crop associated with crop cover using the crop mix provided greater availability of nutrients in the soil compared to the coverage with tropical kudzu.

  7. Multi proxy chemical properties of freshwater sapropel

    Science.gov (United States)

    Stankevica, Karina; Rutina, Liga; Burlakovs, Juris; Klavins, Maris

    2014-05-01

    Freshwater sapropel is organic rich lake sediment firstly named "gyttja" by Hampus van Post in 1862. It is composed of organic remains such as shell detritus, plankton, chitin of insects, spores of higher plants and mineral part formed in eutrophic lake environments. The most appropriate environments for the formation of sapropel are in shallow, overgrown post-glacial lakes and valleys of big rivers in boreal zone, while thick deposits of such kind of organic sediments rarely can be found in lakes on permafrost, mountainous regions or areas with increased aridity. Organic lake sediments are divided in 3 classes according the content of organic matter and mineral part: biogenic, clastic and mixed. The value of sapropel as natural resource increases with the content of organic matter and main applications of sapropel are in agriculture, medicine, cosmetic and chemical industry. The research of sapropel in Latvia has shown that the total amount of this natural resource is close to 2 billion m3 or ~500 million tons. Sapropel has fine, dispersed structure and is plastic, but colour due to the high natural content of phosphorus usually is dark blue, later after drying it becomes light blue. Main research of the sapropel nowadays is turned to investigation of interactions among organic and mineral part of the sapropel with living organisms thus giving the inside look in processes and biological activity of the formation. From the chemical point of view sapropel contains lipids (bitumen), water-soluble substances that are readily hydrolyzed, including humic and fulvic acids, cellulose and the residual part, which does not hydrolyze. In this work we have analyzed the class of organic sapropel: peaty, cyanobacterial and green algal types, as well as siliceous sapropel, in order to determine the presence of biologically active substances, including humic substances, proteins and enzymes as well as to check free radical scavenging activity. Samples were collected from lakes

  8. Chemical and structural analysis of Eucalyptus globulus and E. camaldulensis leaf cuticles: a lipidized cell wall region

    Directory of Open Access Journals (Sweden)

    Paula eGuzmán

    2014-09-01

    Full Text Available The plant cuticle has traditionally been conceived as an independent hydrophobic layer that covers the external epidermal cell wall. Due to its complexity, the existing relationship between cuticle chemical composition and ultra-structure remains unclear to date. This study aimed to examine the link between chemical composition and structure of isolated, adaxial leaf cuticles of Eucalyptus camaldulensis and E. globulus by the gradual extraction and identification of lipid constituents (cutin and soluble lipids, coupled to spectroscopic and microscopic analyses. The soluble compounds and cutin monomers identified could not be assigned to a concrete internal cuticle ultra-structure. After cutin depolymerization, a cellulose network resembling the cell wall was observed, with different structural patterns in the regions ascribed to the cuticle proper and cuticular layer, respectively. Our results suggest that the current cuticle model should be revised, stressing the presence and major role of cell wall polysaccharides. It is concluded that the cuticle may be interpreted as a modified cell wall region which contains additional lipids. The major heterogeneity of the plant cuticle makes it difficult to establish a direct link between cuticle chemistry and structure with the existing methodologies.

  9. Chemical and structural analysis of Eucalyptus globulus and E. camaldulensis leaf cuticles: a lipidized cell wall region.

    Science.gov (United States)

    Guzmán, Paula; Fernández, Victoria; Graça, José; Cabral, Vanessa; Kayali, Nour; Khayet, Mohamed; Gil, Luis

    2014-01-01

    The plant cuticle has traditionally been conceived as an independent hydrophobic layer that covers the external epidermal cell wall. Due to its complexity, the existing relationship between cuticle chemical composition and ultra-structure remains unclear to date. This study aimed to examine the link between chemical composition and structure of isolated, adaxial leaf cuticles of Eucalyptus camaldulensis and E. globulus by the gradual extraction and identification of lipid constituents (cutin and soluble lipids), coupled to spectroscopic and microscopic analyses. The soluble compounds and cutin monomers identified could not be assigned to a concrete internal cuticle ultra-structure. After cutin depolymerization, a cellulose network resembling the cell wall was observed, with different structural patterns in the regions ascribed to the cuticle proper and cuticular layer, respectively. Our results suggest that the current cuticle model should be revised, stressing the presence and major role of cell wall polysaccharides. It is concluded that the cuticle may be interpreted as a modified cell wall region which contains additional lipids. The major heterogeneity of the plant cuticle makes it difficult to establish a direct link between cuticle chemistry and structure with the existing methodologies.

  10. Chemical constituents of Cinnamomum septentrionale leaf litter and its allelopathic activity on the growth of maize (Zea mays).

    Science.gov (United States)

    Yang, Shanshan; Hu, Hongling; Hu, Tingxing; Wang, Qian; Ye, Mao; Luo, Jie; Peng, Yong; Zhang, Ruyi

    2017-06-01

    A pot experiment was conducted to study the effect of decomposing Cinnamomum septentrionale leaf litter on the growth of maize. In this study, the morphological traits of maize were significantly inhibited when the leaf litter amount reached or exceeded 40 g per pot; Furthermore, during the early growth stage or with a large amount of litter addition, the pigment contents were inhibited by C. septentrionale leaf litter. Gas chromatography-mass spectrometry was used to determine the volatile substances of leaf litter and 34 compounds were identified, several of which were reported to be phytotoxic. In conclusion, the leaf litter of C. septentrionale showed a strong allelopathic effect on the growth of maize. Thus, it is better to avoid the growing of maize under or near the C. septentrionale plantation unless the leaf litter could be eliminated in time or other effective leaf litter processing methods could be implemented.

  11. Photosynthetic properties of erect leaf maize inbred lines as the efficient photo-model in breeding and seed production

    Directory of Open Access Journals (Sweden)

    Radenović Čedomir N.

    2003-01-01

    Full Text Available The initial idea of this study was a hypothesis that erect leaf maize inbred lines were characterized by properties of an efficient photo-model and that as such were very desirable in increasing the number of plants per area unit (plant density in the process of contemporary selection and seed production. The application of a non-invasive bioluminescence-photosynthetic method, suitable for the efficiency estimation of the photo-model, verified the hypothesis. Obtained photosynthetic properties of observed erect leaf maize inbred lines were based on the effects and characteristics of thermal processes of delayed chlorophyll fluorescence occurring in their thylakoid membranes. The temperature dependence of the delayed chlorophyll fluorescence intensity phase transitions (critical temperatures in the thylakoid membranes and activation energy are the principal parameters of the thermal processes. Based on obtained photosynthetic properties it is possible to select erect leaf maize inbred lines that are resistant and tolerant to high and very high temperatures, as well as, to drought. They could be good and efficient photo-models wherewith.

  12. Leaf development and photosynthetic properties of three tropical tree species with delayed greening

    NARCIS (Netherlands)

    Cai, Z.Q.; Slot, M.; Fan, Z.X.

    2005-01-01

    Leaf developmental patterns were characterized for three tropical tree species with delayed greening. Changes in the pigment contents, photosynthetic capacity, stomata development, photosystem 2 efficiency, rate of energy dissipation, and the activity of partial protective enzymes were followed in d

  13. Chemical identification and properties of element 112

    CERN Document Server

    Yakushev, A B; Zvára, I

    2002-01-01

    The second experiment on the chemical identification of element 112 performed at the FLNR (Dubna) is reported. Similar to the first test in 2000, the 2 mg/cm sup 2 sup n sup a sup t U target was bombarded with the 262-MeV sup 4 sup 8 Ca ions aiming at the production of sup 2 sup 8 sup 3 112, which as reported earlier decays by SF with a half-life of 3 min. The bombardment products recoiling from the target were thermalized in flowing helium and transported by the gas to detectors 25 m apart. Of all the heavy elements, the reaction products, only Hg, Rn and At were efficiently transported and thus selectively isolated. This time the beam dose was much higher (2.8 centre dot 10 sup 1 sup 8) and two different devices for detecting fission fragments and alpha particles were employed. The device used earlier was an assembly of sixteen PIPS detectors coated with Au to detect 'Hg-like' nuclides being adsorbed on Au at ambient temperature. The new one was a flow-through ionization chamber, 5000 cm sup 3 in volume, wh...

  14. Composition and chemical variability of leaf oil of Myrtus communis from north-eastern Algeria.

    Science.gov (United States)

    Bouzabata, Amel; Boussaha, Faffani; Casanova, Joseph; Tomi, Félix

    2010-10-01

    The chemical composition of 27 oil samples of Myrtus communis isolated from leaves collected in three locations in north-eastern Algeria was investigated by GC(RI) and 13C NMR spectroscopy. Yields ranged between 0.2-1.2% (w/w). The chemical composition of the oils was largely dominated by monoterpene hydrocarbons, with alpha-pinene (40.5-64.0%), 1,8-cineole (10.9-29.1%) and limonene (6.7-8.2%) being the major compounds. In all the samples, 3,3,5,5,8,8-hexamethyl-7-oxabicyclo[4.3.0]non-1(6)-ene-2,4-dione was identified (0.8-1.5%). The composition is similar to that reported for myrtle oils from Corsica, Sardinia and Tunisia, but differed from that of Moroccan and Spanish myrtle oils.

  15. Leaf optical properties shed light on foliar trait variability at individual to global scales

    Science.gov (United States)

    Shiklomanov, A. N.; Serbin, S.; Dietze, M.

    2016-12-01

    Recent syntheses of large trait databases have contributed immensely to our understanding of drivers of plant function at the global scale. However, the global trade-offs revealed by such syntheses, such as the trade-off between leaf productivity and resilience (i.e. "leaf economics spectrum"), are often absent at smaller scales and fail to correlate with actual functional limitations. An improved understanding of how traits vary within communities, species, and individuals is critical to accurate representations of vegetation ecophysiology and ecological dynamics in ecosystem models. Spectral data from both field observations and remote sensing platforms present a potentially rich and widely available source of information on plant traits. In particular, the inversion of physically-based radiative transfer models (RTMs) is an effective and general method for estimating plant traits from spectral measurements. Here, we apply Bayesian inversion of the PROSPECT leaf RTM to a large database of field spectra and plant traits spanning tropical, temperate, and boreal forests, agricultural plots, arid shrublands, and tundra to identify dominant sources of variability and characterize trade-offs in plant functional traits. By leveraging such a large and diverse dataset, we re-calibrate the empirical absorption coefficients underlying the PROSPECT model and expand its scope to include additional leaf biochemical components, namely leaf nitrogen content. Our work provides a key methodological contribution as a physically-based retrieval of leaf nitrogen from remote sensing observations, and provides substantial insights about trait trade-offs related to plant acclimation, adaptation, and community assembly.

  16. Fucoxanthin Derivatives: Synthesis and their Chemical Properties.

    Science.gov (United States)

    Komba, Shiro; Kotake-Nara, Eiichi; Machida, Sachiko

    2015-01-01

    Novel fucoxanthin derivatives that could change the size of mixed micelles were synthesized. The mixed micelles under consideration consist of a bile acid and some additives. To change the affinity against a bile acid, we designed the synthesis of a fucoxanthin-lithocholic acid complex. Lithocholic acid is one of the bile acids. The 3-OH on lithocholic acid was protected by a levulinyl group, and the protected lithocholic acid was selectively coupled via an ester linkage to the 3-OH on fucoxanthin to obtain levulinyl-protected lithocholyl fucoxanthin (LevLF). The levulinyl group was then selectively deprotected using hydrazine to obtain a lithocholyl fucoxanthin (LF). The average sizes of the micelles that contained these compounds (fucoxanthin, LevLF, and LF) with a bile acid (sodium taurocholate) were measured. The LevLF induced larger micelles than fucoxanthin or LF. Interestingly, the addition of 1-oleoyl-rac-glycerol induced a more efficient change in the micelle size. The large micelles grew larger, and the small micelles became smaller. Triple-mixed micelles with LevLF, sodium taurocholate, and 1-oleoyl-rac-glycerol formed the largest micelle with a diameter of 68 nm. On the other hand, triple-mixed micelles using LF, sodium taurocholate, and 1-oleoyl-rac-glycerol made the smallest micelles with diameters as low as 12 nm. We also investigated the hydrolysis of these compounds with enzymes (esterase from porcine liver, lipase from porcine pancreas, and cholesterol esterase from Pseudomonas sp.). The ester linkage between the lithocholic acid and fucoxanthin of LevLF was hydrolyzed with cholesterol esterase. In addition, the intestinal absorption was examined with Caco-2 cells, and no advantageous change in absorption efficiency was observed by chemically modifying the fucoxanthin unless different micelles sizes and increasing hydrophobicity are induced.

  17. Comparison of the chemical alteration trajectory of Liriodendron tulipifera L. leaf litter among forests with different earthworm abundance

    Science.gov (United States)

    Filley, Timothy R.; McCormick, Melissa K.; Crow, Susan E.; Szlavecz, Katalin; Whigham, Dennis F.; Johnston, Cliff T.; van den Heuvel, Ronald N.

    2008-03-01

    To investigate the control of earthworm populations on leaf litter biopolymer decay dynamics, we analyzed the residues of Liriodendron tulipifera L. (tulip poplar) leaves after six months of decay, comparing open surface litter and litter bag experiments among forests with different native and invasive earthworm abundances. Six plots were established in successional tulip poplar forests where sites varied in earthworm density and biomass, roughly 4-10 fold, of nonnative lumbricid species. Analysis of residues by diffuse reflectance Fourier transform infrared spectroscopy and alkaline CuO extraction indicated that open decay in sites with abundant earthworms resulted in residues depleted in cuticular aliphatic and polysaccharide components and enriched in ether-linked lignin relative to open decay in low earthworm abundance plots. Decay within earthworm-excluding litter bags resulted in an increase in aliphatic components relative to initial amendment and similar chemical trajectory to low earthworm open decay experiments. All litter exhibited a decline in cinnamyl-based lignin and an increase in nitrogen content. The influence of earthworm density on the chemical trajectory of litter decay was primarily a manifestation of the physical separation and concentration of lignin-rich and cutin-poor petioles with additional changes promoted by either microorganisms and/or mesofauna resulting in nitrogen addition and polysaccharide loss. These results illustrate how projected increases in invasive earthworm activity in northern North American forests could alter the chemical composition of organic matter in litter residues and potentially organic matter reaching the soil which may result in shifts in the aromatic and aliphatic composition of soils in different systems.

  18. Spatial Variation of Leaf Optical Properties in a Boreal Forest Is Influenced by Species and Light Environment

    Science.gov (United States)

    Atherton, Jon; Olascoaga, Beñat; Alonso, Luis; Porcar-Castell, Albert

    2017-01-01

    Leaf Optical Properties (LOPs) convey information relating to temporally dynamic photosynthetic activity and biochemistry. LOPs are also sensitive to variability in anatomically related traits such as Specific Leaf Area (SLA), via the interplay of intra-leaf light scattering and absorption processes. Therefore, variability in such traits, which may demonstrate little plasticity over time, potentially disrupts remote sensing estimates of photosynthesis or biochemistry across space. To help to disentangle the various factors that contribute to the variability of LOPs, we defined baseline variation as variation in LOPs that occurs across space, but not time. Next we hypothesized that there were two main controls of potentially disruptive baseline spatial variability of photosynthetically-related LOPs at our boreal forest site: light environment and species. We measured photosynthetically-related LOPs in conjunction with morphological, biochemical, and photosynthetic leaf traits during summer and across selected boreal tree species and vertical gradients in light environment. We then conducted a detailed correlation analysis to disentangle the spatial factors that control baseline variability of leaf traits and, resultantly, LOPs. Baseline spatial variability of the Photochemical Reflectance Index (PRI) was strongly influenced by species and to a lesser extent light environment. Baseline variability of spectral fluorescence derived LOPs was less influenced by species; however at longer near-infrared wavelengths, light environment was an important control. In summary, remote sensing of chlorophyll fluorescence has good potential to detect variation in photosynthetic performance across space in boreal forests given reduced sensitivity to species related baseline variability in comparison to the PRI. Our results also imply that spatially coarse remote sensing observations are potentially unrepresentative of the full scope of natural variation that occurs within a boreal

  19. Sensory properties and chemical composition of Sharri cheese from Kosovo

    Directory of Open Access Journals (Sweden)

    Agim Rysha

    2014-11-01

    Full Text Available Food sensory properties, analyses and chemical composition are very important because they provide information about product quality and end-user acceptance or preferences. An assessment of sensory characteristics and chemical composition of mountain sheep and cow’s-milk cheese from shepherd’s huts and industrial manufacturers in Kosovo was carried out. Consumer-oriented tests using a 9 point hedonic scale were conducted in order to determine Sharri cheese acceptability. Chemical parameters (fat content, fat content of dry matter, acidity, protein, dry matter, mineral and water content and sodium chloride content of 45-day brine cheese samples were also analyzed. Chemical and sensory assessment demonstrated large property differences. A recommendation stems from the results showing that the standardization of both artisanal and industrial production of Sharri cheese is required.

  20. The effect of milkfat melting properties on chemical and physical properties of 20% reformulated cream

    OpenAIRE

    Scott, Lisa Lenore

    1999-01-01

    The Effect of Milkfat Melting Properties on Chemical and Physical Properties of 20% Reformulated Cream Lisa L. Scott (ABSTRACT) Skim, sweet buttermilk, and butter derived aqueous phase components were used to re-emulsify low-melt and medium-melt fraction butteroils to yield 20% milkfat creams. The implications of separation temperature in obtaining components, melting point characteristics, and formulation on the chemical and physical properties of reformulated and natural crea...

  1. Change in hydraulic properties and leaf traits of a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Directory of Open Access Journals (Sweden)

    B. Schuldt

    2010-11-01

    Full Text Available In a throughfall displacement experiment on Sulawesi, Indonesia, three 0.16 ha stands of a premontane perhumid rainforest were exposed to a two-year soil desiccation period that reduced the soil moisture in the upper soil layers beyond the conventional wilting point. About 25 variables, including leaf morphological and chemical traits, stem diameter growth and hydraulic properties of the xylem in the trunk and terminal twigs, were investigated in trees of the tall-growing tree species Castanopsis acuminatissima (Fagaceae by comparing desiccated roof plots with nearby control plots. We tested the hypotheses that this tall and productive species is particularly sensitive to drought, and the exposed upper sun canopy is more affected than the shade canopy. Hydraulic conductivity in the xylem of terminal twigs normalised to vessel lumen area was reduced by 25%, leaf area-specific conductivity by 10–33% during the desiccation treatment. Surprisingly, the leaves present at the end of the drought treatment were significantly larger, but not smaller in the roof plots, though reduced in number (about 30% less leaves per unit of twig sapwood area, which points to a drought effect on the leaf bud formation while the remaining leaves may have profited from a surplus of water. Mean vessel diameter and axial conductivity in the outermost xylem of the trunk were significantly reduced and wood density increased, while annual stem diameter increment decreased by 26%. In contradiction to our hypotheses, (i we found no signs of major damage to the C. acuminatissima trees nor to any other drought sensitivity of tall trees, and (ii the exposed upper canopy was not more drought susceptible than the shade canopy.

  2. Effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of Moringa oleifera.

    Science.gov (United States)

    Shih, Ming-Chih; Chang, Cheng-Ming; Kang, Sue-Ming; Tsai, Min-Lang

    2011-01-01

    Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD) activity except the stalk part.

  3. Effect of Different Parts (Leaf, Stem and Stalk and Seasons (Summer and Winter on the Chemical Compositions and Antioxidant Activity of Moringa oleifera

    Directory of Open Access Journals (Sweden)

    Cheng-Ming Chang

    2011-09-01

    Full Text Available Moringa oleifera, Lam. (Moringaceae is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk and seasons (summer and winter on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part, calcium and phenolic compounds (except the leaf part and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD activity except the stalk part.

  4. Blue light dose–responses of leaf photosynthesis, morphology, and chemical composition of Cucumis sativus grown under different combinations of red and blue light

    NARCIS (Netherlands)

    Hogewoning, S.W.; Trouwborst, G.; Maljaars, H.; Poorter, H.; Ieperen, van W.; Harbinson, J.

    2010-01-01

    The blue part of the light spectrum has been associated with leaf characteristics which also develop under high irradiances. In this study blue light dose–response curves were made for the photosynthetic properties and related developmental characteristics of cucumber leaves that were grown at an eq

  5. Nanodispersed Oxides-Plasma-Chemical Synthesis and Properties

    Institute of Scientific and Technical Information of China (English)

    Gheorghi VISSOKOV; Katerina ZAHARIEVA

    2007-01-01

    We discuss the plasma-chemical synthesis and the properties of transition metals oxides, Al2O3, SiO2, rare-earth oxides, oxides for ceramics and metal-ceramics, and oxides used as catalysts. Bearing in mind the indisputable advantages of using plasma-chemically synthesized nanodispersed oxides for the needs of various industrial fields, we set out to review the articles published in the past few years devoted to the problems of plasma-chemical synthesis and characterization of nanodispersed oxides.

  6. Chemical stimulants of leaf-trenching by cabbage loopers: natural products, neurotransmitters, insecticides, and drugs.

    Science.gov (United States)

    Dussourd, David E

    2003-09-01

    Larvae of the cabbage looper, Trichoplusia ni (Lepidoptera: Noctuidae), often transect leaves with a narrow trench before eating the distal section. The trench reduces larval exposure to exudates, such as latex, during feeding. Plant species that do not emit exudate, such as Plantago lanceolata, are not trenched. However, if exudate is applied to a looper's mouth during feeding on P. lanceolata, the larva will often stop and cut a trench. Dissolved chemicals can be similarly applied and tested for effectiveness at triggering trenching. With this assay, I have documented that lactucin from lettuce latex (Lactuca sativa), myristicin from parsley oil (Petroselinum crispum), and lobeline from cardinal flower (Lobelia cardinalis) elicit trenching. These compounds are the first trenching stimulants reported. Several other constituents of lettuce and parsley, including some phenylpropanoids, monoterpenes, and furanocoumarins had little or no activity. Cucurbitacin E glycoside found in cucurbits, another plant family trenched by cabbage loopers, also was inactive. Lactucin, myristicin, and lobeline all affect the nervous system of mammals, with lobeline acting specifically as an antagonist of nicotinic acetylcholine receptors. To determine if cabbage loopers respond selectively to compounds active at acetylcholine synapses, I tested several neurotransmitters, insecticides, and drugs with known neurological activity, many of which triggered trenching. Active compounds included dopamine, serotonin, the insecticide imidacloprid, and various drugs such as ipratropium, apomorphine, buspirone, and metoclopramide. These results document that noxious plant chemicals trigger trenching, that loopers respond to different trenching stimulants in different plants, that diverse neuroactive chemicals elicit the behavior, and that feeding deterrents are not all trenching stimulants. The trenching assay offers a novel approach for identifying defensive plant compounds with potential uses

  7. Stem and leaf hydraulic properties are finely coordinated in three tropical rain forest tree species.

    Science.gov (United States)

    Nolf, Markus; Creek, Danielle; Duursma, Remko; Holtum, Joseph; Mayr, Stefan; Choat, Brendan

    2015-12-01

    Coordination of stem and leaf hydraulic traits allows terrestrial plants to maintain safe water status under limited water supply. Tropical rain forests, one of the world's most productive biomes, are vulnerable to drought and potentially threatened by increased aridity due to global climate change. However, the relationship of stem and leaf traits within the plant hydraulic continuum remains understudied, particularly in tropical species. We studied within-plant hydraulic coordination between stems and leaves in three tropical lowland rain forest tree species by analyses of hydraulic vulnerability [hydraulic methods and ultrasonic emission (UE) analysis], pressure-volume relations and in situ pre-dawn and midday water potentials (Ψ). We found finely coordinated stem and leaf hydraulic features, with a strategy of sacrificing leaves in favour of stems. Fifty percent of hydraulic conductivity (P50 ) was lost at -2.1 to -3.1 MPa in stems and at -1.7 to -2.2 MPa in leaves. UE analysis corresponded to hydraulic measurements. Safety margins (leaf P50 - stem P50 ) were very narrow at -0.4 to -1.4 MPa. Pressure-volume analysis and in situ Ψ indicated safe water status in stems but risk of hydraulic failure in leaves. Our study shows that stem and leaf hydraulics were finely tuned to avoid embolism formation in the xylem.

  8. Microencapsulation of maqui (Aristotelia chilensis Molina Stuntz leaf extracts to preserve and control antioxidant properties

    Directory of Open Access Journals (Sweden)

    Leslie Vidal J

    2013-03-01

    Full Text Available Microencapsulation technology is an alternative to stabilize stress factors and protect food ingredients or additives, which include environmentally sensitive bioactive principles in protective matrices to increase their functionality and life span. The objective of this research was to study conditions to obtain microcapsules with antioxidant capacity from a maqui (Aristotelia chilensis [Molina] Stuntz, Elaeocarpaceae leaf extract by emulsification and subsequent retention after microencapsulation. Microcapsules were produced by water-in-oil emulsion (W/O using a phase of the aqueous maqui leaf extract and gum arabic, and a liquid vaseline phase. Maqui leaf extract antioxidant capacity was 99.66% compared with the aqueous phase of the emulsion at 94.38 and 93.06% for 5% and 15% gum arabic, respectively. The mean yield of maqui leaf extract microencapsulation with 5% gum arabic varied between 38 and 48%, whereas with 15% gum arabic it was 39%. Once the antioxidant microcapsules were formed, mean extract antioxidant capacity ranged between 30 and 35%. Both yields responded similarly to changes in gum arabic concentrations (5% and 15% in the aqueous phase of the emulsion; 5% concentration produced a microcapsule size from 1.0 to 10 urn. Maqui leaf extracts with high phenolic compound levels, which can be stabilized and protected by the microencapsulation process, produce new natural preservative systems as compared with their synthetic counterparts.

  9. Leaf surface lipophilic compounds as one of the factors of silver birch chemical defense against larvae of gypsy moth.

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

    Full Text Available Plant chemical defense against herbivores is a complex process which involves a number of secondary compounds. It is known that the concentration of leaf surface lipophilic compounds (SLCs, particularly those of flavonoid aglycones are increased with the defoliation treatment of silver birch Betula pendula. In this study we investigated how the alteration of SLCs concentration in the food affects the fitness and innate immunity of the gypsy moth Lymantria dispar. We found that a low SLCs concentrations in consumed leaves led to a rapid larval development and increased females' pupae weight (= fecundity compared to larvae fed with leaves with high SLCs content. Inversely, increasing the compounds concentration in an artificial diet produced the reverse effects: decreases in both larval weight and larval survival. Low SLCs concentrations in tree leaves differently affected larval innate immunity parameters. For both sexes, total hemocytes count in the hemolymph increased, while the activity of plasma phenoloxidase decreased when larvae consume leaves with reduced content of SLCs. Our results clearly demonstrate that the concentration of SLCs in silver birch leaves affects not only gypsy moth fitness but also their innate immune status which might alter the potential resistance of insects against infections and/or parasitoids.

  10. The use of bay leaf (Eugenia polyantha Wight in dentistry

    Directory of Open Access Journals (Sweden)

    Agus Sumono

    2008-09-01

    Full Text Available Background: Bay leaf or Eugenia polyantha Wight is a species that has several chemical properties. Bay leaf consists of tanine, flavonoid, essensial oil, including citric acid and eugenol. However, only few reports were published about the use of bay leaf in dentistry. Purpose: The aim of this article is to describe the chemical properties of Eugenia polyantha Wight that are widely used in dentistry. Reviews: The chemical properties of Eugenia polyantha Wight have analgesic, antibacterial, and anti-inflammatory effect, so they can be used as an alternative dental therapy. These properties can be used as a basic of therapy or as a basic ingredients of treatment. Conclusion: Eugenia polyantha Wight has some useful pharmacologic activities that are useful in dentistry. We suggest this article can be used as a basic knowledge for dental researchers.

  11. EVALUATION OF CHEMICALS INCORPORATED WOOD FIBRE CEMENT MATRIX PROPERTIES

    Directory of Open Access Journals (Sweden)

    MST. SADIA MAHZABIN

    2013-08-01

    Full Text Available Wood fibre cement (WFC boards are well established commercially and widely used in many developed countries. The combination of the properties of two important materials, i.e., cement, and previously treated fibrous materials like wood or agricultural residues; which made up the board, contributed in the performance of the board as building material. In this work, the WFC matrix (WFCM samples are produced to determine the physical properties of WFCM such as the density and water absorption. The wood fibres are incorporated/treated with three different chemical additives; calcium formate (Ca(HCOO2, sodium silicate (Na2.SiO3 and magnesium chloride (MgCl2 prior to mixing with cement. The mechanical properties of the WFCM, with or without chemicals treatment of fibres, such as the compressive strength and flexural strength are evaluated. Three wood/cement ratios (50:50, 40:60, 30:70 are used and the percentages of water and accelerator were 80% and 3% based on the cement weight, respectively. Three moisture-conditioned samples; accelerated aging, dry and wet conditions are used for flexural test. The results reveal that the wood/cement ratio, chemical additives and moisture content had a marked influence on the physical and mechanical properties of the matrix. Finally, it has been shown that the 40:60 wood/cement ratio samples with prior chemicals treatment of the fibres that undergo accelerated aging conditioning achieve higher strength then dry and wet-conditioned boards.

  12. Physical, chemical and electrochemical properties of pure and doped ceria

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Sammes, N.M.; Tompsett, G.A.

    2000-01-01

    This paper gives an extract of available data on the physical, chemical, electrochemical and mechanical properties of pure and doped ceria, predominantly in the temperature range from 200 to 1000 degrees C. Several areas are pointed out where further research is needed in order to make a better...

  13. Physical, Chemical, Functional and Sensory Properties of the 'White ...

    African Journals Online (AJOL)

    The result of the chemical analysis shows the moisture, protein, fat. ... The functional properties were also analyzed and the results for the water and oil ... Also, the swelling index, foam capacity, emulsion capacity and wettability were 223 ml/ml ...

  14. Physico-chemical properties of Safou (Dacryodes edulis) fruits ...

    African Journals Online (AJOL)

    SARAH

    2016-09-30

    Sep 30, 2016 ... 2016 Physico-chemical properties of Safou (Dacryodes edulis) fruits grown in. Côte d'Ivoire .... test, 5 trees were selected randomly and separately from the CNRA ... of the crucible and its content on ignition. Carbohydrate.

  15. Comparative Studies of Physico-chemical Properties of Some ...

    African Journals Online (AJOL)

    Akorede

    ABSTRACT: The aim of this study was to evaluate some physico-chemical properties of four major general purpose ... In the year 2006 alone, four cases of such collapses .... (ASTM, 1986). The percentage SiO2 was calculated using. Eqn (11).

  16. Linkages between aggregate formation, porosity and soil chemical properties

    NARCIS (Netherlands)

    Regelink, I.C.; Stoof, C.R.; Rousseva, S.; Weng, L.; Lair, G.J.; Kram, P.; Nikolaidis, N.P.; Kercheva, M.; Banwart, S.; Comans, R.N.J.

    2015-01-01

    Linkages between soil structure and physical–chemical soil properties are still poorly understood due to the wide size-range at which aggregation occurs and the variety of aggregation factors involved. To improve understanding of these processes, we collected data on aggregate fractions, soil

  17. Surface Chemical Properties of Colloids in Main Soils of China

    Institute of Scientific and Technical Information of China (English)

    MAYI-JIE; YUANCHAO-LIANG

    1991-01-01

    Surface chemical properties of soil colloids are the important factor affecting soil fertility and genesis.To provide scientific basis for soil genetic classification,promotion of soil fertility and reasonable fertilizqation,the specific surface area and electric charge of soil colloids in relation to clay minerals and organic matter are further discussed on the basis of the results obtained from the studies on surface chemical properties of soil colloids in five main soils of China.Results from the studies show that the effect of clay minerals and organic matter on the surface chemical properties of soil colloids is very complicated because the siloxane surface,hydrated oxide surface and organic matter surface do not exist separately,but they are always mixed together and influenced each other.The understanding of the relationship among clay minerals,organic matter and surface chemical properties of soil colloids depends upon further study of the relevant disciplines of soil science,especially the study on the mechanisms of organo-mineral complexes.

  18. Composition and Thermodynamic Properties of Air in Chemical Equilibrium

    Science.gov (United States)

    Moeckel, W E; Weston, Kenneth C

    1958-01-01

    Charts have been prepared relating the thermodynamic properties of air in chemical equilibrium for temperatures to 15,000 degrees k and for pressures 10(-5) to 10 (plus 4) atmospheres. Also included are charts showing the composition of air, the isentropic exponent, and the speed of sound. These charts are based on thermodynamic data calculated by the National Bureau of Standards.

  19. 40 CFR 716.50 - Reporting physical and chemical properties.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reporting physical and chemical properties. 716.50 Section 716.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT HEALTH AND SAFETY DATA REPORTING General Provisions § 716.50 Reporting physical and...

  20. Physico-chemical properties of probiotic yoghurt produced with transglutaminase

    Directory of Open Access Journals (Sweden)

    Milanović Spasenija D.

    2007-01-01

    Full Text Available The effect of different concentration of transglutaminase - TG (0.02%, 0.06% and 0.12% on physico-chemical properties of probiotic yoghurt was investigated. Two series of yoghurt were manufactured on a laboratory scale from pasteurised skim milk (0.1 % w/w fat. Series I was produced with TGase activation during a period of 2 h at 40°C, while series II was produced without enzyme activation. Then, the adequate quantities of TGase and probiotic starter culture ABT-4 (Chr. Hansen A/S Denmark were added. Chemical composition, physico-chemical properties (water holding capacity and whey separation and sensory characteristics of yoghurt samples were determined after production and during 5 days of storage. Addition of TGase to milk (direct or after activation for probiotic yoghurt manufacture improved its overall characteristics. Activation of TG in yoghurt production increases water holding capacity as well as decreases syneresis during the storage.

  1. Evaluation of plant activator and chemical fungicides on leaf blight (Bipolaris sorokiniana) development and yield of wheat.

    Science.gov (United States)

    Aminuzzaman, F M; Hossain, I

    2007-06-01

    Bion 50 WG (Benzothiodiazole), Tilt-250 EC (Propiconazole) and Amistar (Azoxystrobin) either alone and some of their combinations were evaluated against leaf blight/spot (Bipolaris sorokiniana) development and yield of wheat. All the treatments significantly reduced leaf spot reaction of wheat over untreated control. But Bion in combination with Amistar resulted significantly highest reduction of leaf spot reaction of wheat (p = 0.05) against all the tested pathotypes inoculated at flag leaf stage. In the field, Bion reduced leaf spot severity at heading and flowering stage in 2000-2001 and at hard dough stage in 2001-2002. Number of grains/ear not significantly increased by treating seeds with Bion though 1000-grain weight is significantly increased (p = 0.05) in 2000-2001 by Bion. Statistically higher grain yield was obtained from the experimental plot by treating seeds with Bion and Amistar. Bion resulted 53.33% higher grain yield in compare to untreated control.

  2. Quantitative and qualitative shifts in defensive metabolites define chemical defense investment during leaf development in Inga, a genus of tropical trees.

    Science.gov (United States)

    Wiggins, Natasha L; Forrister, Dale L; Endara, María-José; Coley, Phyllis D; Kursar, Thomas A

    2016-01-01

    Selective pressures imposed by herbivores are often positively correlated with investments that plants make in defense. Research based on the framework of an evolutionary arms race has improved our understanding of why the amount and types of defenses differ between plant species. However, plant species are exposed to different selective pressures during the life of a leaf, such that expanding leaves suffer more damage from herbivores and pathogens than mature leaves. We hypothesize that this differential selective pressure may result in contrasting quantitative and qualitative defense investment in plants exposed to natural selective pressures in the field. To characterize shifts in chemical defenses, we chose six species of Inga, a speciose Neotropical tree genus. Focal species represent diverse chemical, morphological, and developmental defense traits and were collected from a single site in the Amazonian rainforest. Chemical defenses were measured gravimetrically and by characterizing the metabolome of expanding and mature leaves. Quantitative investment in phenolics plus saponins, the major classes of chemical defenses identified in Inga, was greater for expanding than mature leaves (46% and 24% of dry weight, respectively). This supports the theory that, because expanding leaves are under greater selective pressure from herbivores, they rely more upon chemical defense as an antiherbivore strategy than do mature leaves. Qualitatively, mature and expanding leaves were distinct and mature leaves contained more total and unique metabolites. Intraspecific variation was greater for mature leaves than expanding leaves, suggesting that leaf development is canalized. This study provides a snapshot of chemical defense investment in a speciose genus of tropical trees during the short, few-week period of leaf development. Exploring the metabolome through quantitative and qualitative profiling enables a more comprehensive examination of foliar chemical defense investment.

  3. Coordination of leaf and stem water transport properties in tropical forest trees

    Science.gov (United States)

    Frederick C. Meinzer; David R. Woodruff; Jean-Christophe Domec; Guillermo Goldstein; Paula I. Campanello; Genoveva M. Gatti; Randol Villalobos-Vega

    2008-01-01

    Stomatal regulation of transpiration constrains leaf water potential (ψ l) within species-specific ranges that presumably avoid excessive tension and embolism in the stem xylem upstream. However, the hydraulic resistance of leaves can be highly variable over short time scales, uncoupling tension in the xylem of leaves from that in the...

  4. Study of the Properties of Bearberry Leaf Extract as a Natural Antioxidant in Model Foods.

    Science.gov (United States)

    Mohd Azman, Nurul Aini; Gallego, Maria Gabriela; Segovia, Francisco; Abdullah, Sureena; Shaarani, Shalyda Md; Almajano Pablos, María Pilar

    2016-04-01

    The common bearberry (Arctostaphylos uva-ursi L. Sprengel) is a ubiquitous procumbent evergreen shrub located throughout North America, Asia, and Europe. The fruits are almost tasteless but the plant contains a high concentration of active ingredients. The antioxidant activity of bearberry leaf extract in the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation assay was 90.42 mmol Trolox equivalents/g dry weight (DW). The scavenging ability of the methanol extract of bearberry leaves against methoxy radicals generated in the Fenton reaction was measured via electron paramagnetic resonance. Lipid oxidation was retarded in an oil-water emulsion by adding 1 g/kg lyophilised bearberry leaf extract. Also, 1 g/kg of lyophilised bearberry leaf extract incorporated into a gelatin-based film displayed high antioxidant activity to retard the degradation of lipids in muscle foods. The present results indicate the potential of bearberry leaf extract for use as a natural food antioxidant.

  5. Study of the Properties of Bearberry Leaf Extract as a Natural Antioxidant in Model Foods

    Directory of Open Access Journals (Sweden)

    Nurul Aini Mohd Azman

    2016-04-01

    Full Text Available The common bearberry (Arctostaphylos uva-ursi L. Sprengel is a ubiquitous procumbent evergreen shrub located throughout North America, Asia, and Europe. The fruits are almost tasteless but the plant contains a high concentration of active ingredients. The antioxidant activity of bearberry leaf extract in the 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS radical cation assay was 90.42 mmol Trolox equivalents/g dry weight (DW. The scavenging ability of the methanol extract of bearberry leaves against methoxy radicals generated in the Fenton reaction was measured via electron paramagnetic resonance. Lipid oxidation was retarded in an oil–water emulsion by adding 1 g/kg lyophilised bearberry leaf extract. Also, 1 g/kg of lyophilised bearberry leaf extract incorporated into a gelatin-based film displayed high antioxidant activity to retard the degradation of lipids in muscle foods. The present results indicate the potential of bearberry leaf extract for use as a natural food antioxidant.

  6. Mosquitocidal properties ofSolanum trilobatum L. (Solanaceae) leaf extracts against three important human vector mosquitoes (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Selvaraj Premalatha; Kuppusamy Elumalai; Alagarmalai Jeyasankar

    2013-01-01

    Objective:To determine the larvicidal and pupicidal activites ofSolanum trilobatum(S. trilobatum) leaf extracts againstAedes aegypti(Ae. aegypti),Culex quinquefasciatus(Cx. quinquefasciatus) andAnopheles stephensi(An. stephensi).Methods:The larvicidal and pupucidal was determined at five different concentrations of50,100,150,200 and250 ppm.Percentage of larval mortality was assessed after48 h.Results:Methanol extracts ofS. trilobatum was found to be more susceptible against the larvae ofAe. aegypti,Cx. quinquefasciatus andAn. stephensi at 250 ppm withaLC50 value of125.43,127.77 and116.64 ppm respectively.Leaf methanol extracts ofS. trilobatum also exhibited pupicidal and adult emergence properties.Conclusions:These results suggested that the leaf extracts ofS. trilobatum showed potential to be used as an ideal ecofriendly approach for the control of theAe. Aegypti,Cx. quinquefasciatus andAn. stephensi.

  7. Structural characterization, antioxidant and anticancer properties of gold nanoparticles synthesized from leaf extract(decoction)of Antigonon leptopus Hook. &Arn.

    Science.gov (United States)

    Balasubramani, Govindasamy; Ramkumar, Rajendiran; Krishnaveni, Narayanaswamy; Pazhanimuthu, Annamalai; Natarajan, Thillainathan; Sowmiya, Rajamani; Perumal, Pachiappan

    2015-04-01

    Tea is an aromatic beverage prepared by pouring boiling water over alleviated leaves of the tea plant. Tea prepared from the aerial parts of Antigonon leptopus has been traditionally used as remedy for cold, diabetes and pain in many countries. The gold nanoparticles (Au NPs) synthesized from powdered leaf extract (decoction) of A. leptopus were characterized by UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern and energy dispersive X-ray (EDX) analyses to define the formation of Au NPs. Further, the synthesized Au NPs were well characterized based on their strong surface plasmon resonance (SPR), crystalline nature, functional groups, size and dispersed shapes, purity and Bragg's reflections of face centered cubic (fcc) structure of metallic gold. The Au NPs showed higher free radical scavenging property when compared to the effect of leaf extract. Cytotoxicity study of synthesized Au NPs exhibited the growth inhibitory property at the concentration (GI50) of 257.8 μg/mL in human adenocarcinoma breast cancer (MCF-7) cells after 48 h. Thus, the Au NPs synthesized from the Mexican creeper, A. leptopus revealed the important biological properties: as a free radical as well as anticancer agent. We conclude that the A. leptopus derived biological materials have promising potential as a source for the development of anticancer drug in future.

  8. Physico-Chemical Properties of Kaolin-Organic Acid

    Directory of Open Access Journals (Sweden)

    Yeo S.W.

    2017-01-01

    Full Text Available Soil with more than 20% of organic content is classified as organic soil in Malaysia. Contents of organic soil consist of different types of organic and inorganic matter. Each type of organic matter has its own characteristic and its effect on the properties of the soil is different. Hence, a good understanding on the effect of specific organic and inorganic matter on the physico-chemical characteristic of organic soils can serve as a guide for predicting the properties of organic soils. The main objective is to unveil the effect of organic acid on the physico-chemical properties of soil. Artificial organic soil (kaolin mixed with organic acid was utilized in order to minimize the geochemical variability of studied soil. The organic acid which consists of humic acid and fulvic acid was extracted from highly humificated plant–based compost. The effect of organic acid on the physico-chemical properties of soil was determined by varying the concentration of organic acid. The specific gravity, Atterberg limits, pH, bulk chemical composition and the functional group of kaolin-organic acid were determined. It was found that the plasticity index, specific gravity and pH value were decreased with lowered concentration of organic acid. However, the liquid limits and plastic limits were found to be increased with the concentration decrement of organic acid. The analysis of XRF on the bulk chemical composition and analysis of FTIR spectra on the functional group of artificial organic soils with different concentration have confirmed little geochemical variability between samples.

  9. Chemical constituents and larvicidal potential of Feronia limonia leaf essential oil against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus.

    Science.gov (United States)

    Senthilkumar, A; Jayaraman, M; Venkatesalu, V

    2013-03-01

    In the present investigation, the leaf essential oil of Feronia limonia was evaluated for chemical constituents and mosquito larvicidal activity against the larvae of Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. GC and GC-MS analyses revealed that the essential oil contain 51 compounds. Estragole (34.69 %) and β-pinene(23.59 %) were identified as the major constituents followed by methyl (Z)-caryophyllene (11.05 %), eugenol (6.50 %), linalool (3.97 %), phytol (3.27 %), sabinene (2.41 %) and limonene (2.27 %). Larval mortality was observed after 12 and 24 h of exposure period. The oil showed remarkable larvicidal activity against A. stephensi (LC(50) = 38.93 and LC(90) = 108.64 ppm (after 12 h); LC(50) = 15.03 and LC(90) = 36.69 ppm (after 24 h)), A. aegypti (LC(50) = 37.60 and LC(90) = 104.69 ppm (after 12 h); LC(50) = 11.59 and LC(90) = 42.95 ppm (after 24 h)) and C. quinquefasciatus (LC(50) = 52.08 and LC(90) = 124.33 ppm (after 12 h); LC(50) = 22.49 and LC(90) = 60.90 ppm (after 24 h)). Based on the results, the essential oil of F. limonia can be considered as a new source of larvicide for the control of vector mosquitoes.

  10. Mosquitocidal properties of Calotropis gigantea (Family: Asclepiadaceae) leaf extract and bacterial insecticide, Bacillus thuringiensis, against the mosquito vectors.

    Science.gov (United States)

    Kovendan, Kalimuthu; Murugan, Kadarkarai; Prasanna Kumar, Kanagarajan; Panneerselvam, Chellasamy; Mahesh Kumar, Palanisamy; Amerasan, Duraisamy; Subramaniam, Jayapal; Vincent, Savariar

    2012-08-01

    Calotropis gigantea leaf extract and Bacillus thuringiensis were tested first to fourth-instar larvae and pupae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The medicinal plants were collected from the area around Bharathiar University, Coimbatore, India. Calotropis gigantea leaf was washed with tap water and shade-dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder 500 g of the leaf was extracted with 1.5 L of organic solvents of methanol for 8 h using a Soxhlet apparatus and filtered. The crude leaf extracts were evaporated to dryness in a rotary vacuum evaporator. The plant extract showed larvicidal and pupicidal effects after 24 h of exposure; no mortality was observed in the control group. For Calotropis gigantea, the median lethal concentration values (LC(50)) observed for the larvicidal and pupicidal activities against mosquito vector species Anopheles stephensi I to IV larval instars and pupae were 73.77, 89.64, 121.69, 155.49, and 213.79 ppm; Aedes aegypti values were 92.27, 106.60, 136.48, 164.01, and 202.56 ppm; and Culex quinquefasciatus values were 104.66, 127.71, 173.75, 251.65, and 314.70 ppm, respectively. For B. thuringiensis, the LC(50) values of I to IV larval instars and pupae of Anopheles stephensi were 37.24, 45.41, 57.82, 80.09, and 98.34 ppm; Aedes aegypti values were 42.38, 51.90, 71.02, 96.17, and 121.59 ppm; and Culex quinquefasciatus values were 55.85, 68.07, 94.11, 113.35, and 133.87 ppm, respectively. The study proved that the methanol leaf extract of Calotropis gigantea and bacterial insecticide B. thuringiensis has mosquitocidal property and was evaluated as target species of mosquito vectors. This is an ideal ecofriendly approach for the control of vector control programs.

  11. Physical and chemical properties of pomegranate fruit accessions from Croatia.

    Science.gov (United States)

    Radunić, Mira; Jukić Špika, Maja; Goreta Ban, Smiljana; Gadže, Jelena; Díaz-Pérez, Juan Carlos; MacLean, Dan

    2015-06-15

    The objective was to evaluate physical and chemical properties of eight pomegranate accessions (seven cultivars and one wild genotype) collected from the Mediterranean region of Croatia. Accessions showed high variability in fruit weight and size, calyx and peel properties, number of arils per fruit, total aril weight, and aril and juice yield. Variables that define sweet taste, such as low total acidity (TA; 0.37-0.59%), high total soluble solids content (TSS; 12.5-15.0%) and their ratio (TSS/TA) were evaluated, and results generally aligned with sweetness classifications of the fruit. Pomegranate fruit had a high variability in total phenolic content (1985.6-2948.7 mg/L). HPLC-MALDI-TOF/MS analysis showed that accessions with dark red arils had the highest total anthocyanin content, with cyanidin 3-glucoside as the most abundant compound. Principal component analysis revealed great differences in fruit physical characteristics and chemical composition among pomegranate accessions.

  12. Enhancement of Hevea brasiliensis properties through chemical application

    Directory of Open Access Journals (Sweden)

    ROSZAINI KADIR

    Full Text Available ABSTRACT The effects of four different types of bleaching agents (hydrogen peroxide, sodium hypochlorite, sodium chlorite and oxalic acid mixed together with 2% boron-based preservative (Celbor SP were studied on green sawn rubberwood. Two concentration levels (1% and 2% of were used. Whitish values (W and colour changes (ΔE of sawn rubberwood were assessed before and after chemical treatment using a colour meter. Preliminary observation indicated that timber treated with 1% and 2% hydrogen peroxide produced better and more homogeneous colour properties. Hydrogen peroxide treated timber gave higher whitish values (6.23 and 9.91 for 1% and 2% solution, respectively and lower colour changes (8.49 and 5.51 for 1% and 2% solution, respectively when compared to the other three chemicals. Evaluation on the effects of bleaching (hydrogen peroxide with a higher level of concentration on physical, mechanical and biological properties of rubberwood also have been determined in this study.

  13. Surface properties of hydrogenated nanodiamonds: a chemical investigation.

    Science.gov (United States)

    Girard, H A; Petit, T; Perruchas, S; Gacoin, T; Gesset, C; Arnault, J C; Bergonzo, P

    2011-06-28

    Hydrogen terminations (C-H) confer to diamond layers specific surface properties such as a negative electron affinity and a superficial conductive layer, opening the way to specific functionalization routes. For example, efficient covalent bonding of diazonium salts or of alkene moieties can be performed on hydrogenated diamond thin films, owing to electronic exchanges at the interface. Here, we report on the chemical reactivity of fully hydrogenated High Pressure High Temperature (HPHT) nanodiamonds (H-NDs) towards such grafting, with respect to the reactivity of as-received NDs. Chemical characterizations such as FTIR, XPS analysis and Zeta potential measurements reveal a clear selectivity of such couplings on H-NDs, suggesting that C-H related surface properties remain dominant even on particles at the nanoscale. These results on hydrogenated NDs open up the route to a broad range of new functionalizations for innovative NDs applications development.

  14. QSPR between Physical- Chemical Properties and Molecule Parameters of Alkanes

    Institute of Scientific and Technical Information of China (English)

    XU Qing-qing; LI Liang-chao; HU Li-ya

    2005-01-01

    A set of molecule parameters, namely, N, N′, p, q,n, were used to express the structures of alkanes. A correlative model was established between certain physical-chemical properties and molecular parameters of alkanes by regression method. Eightphysical-chemical properties, such as evaporation heat (△vH20m ),density(D20 ), capacity(C20 ), surface tension(σ20 ), boiling point ( Tb ), critical temperature ( Tc ), critical pressure (Pc) and critical volume(Vc), of fifty-six C3-C16 alkanes were calculated directly from the model in this paper. The calculated values are in good accordance with the literature ones reported for alkanes, and the correlation coefficients (R) equal or exceed 0.99. The research results indicate that the principle of the method is simple and clear, the method is practical, the correlativity is excellent, and the predicted data are credible.

  15. Research on lunar materials. [optical, chemical, and electrical properties

    Science.gov (United States)

    Gold, T.

    1978-01-01

    Abstracts of 14 research reports relating to investigations of lunar samples are presented. The principal topics covered include: (1) optical properties of surface and core samples; (2) chemical composition of the surface layers of lunar grains: Auger electron spectroscopy of lunar soil and ground rock samples; (3) high frequency electrical properties of lunar soil and rock samples and their relevance for the interpretation of lunar radar observations; (4) the electrostatic dust transport process; (5) secondary electron emission characteristics of lunar soil samples and their relevance to the dust transportation process; (6) grain size distribution in surface soil and core samples; and (7) the optical and chemical effects of simulated solar wind (2keV proton and a particle radiation) on lunar material.

  16. Preparing superhydrophobic copper surfaces with rose petal or lotus leaf property using a simple etching approach

    Science.gov (United States)

    Talesh Bahrami, H. R.; Ahmadi, B.; Saffari, H.

    2017-05-01

    A facile chemical etching process is developed to fabricate superhydrophobic copper surfaces. In the first step, cleaned copper surfaces immersed in ferric chloride (FeCl3) solutions with specific concentrations for different times. Etched surfaces exhibit the maximum contact angle of 140°. They have large sliding angle and water droplets stuck to the surface even if they were turned upside down which is well-known as rose petal effect. After stearic acid modification of etched surfaces, their contact angle slightly increased to above 150° and sliding angle decreased to smaller than 10° in some cases, which is same as lotus plant leaves property against water. Inspecting SEM images of etched surfaces reveals that many micro-nano structures forming blossom like buildings with curved petals of nanoscale thicknesses are formed. The micro-nano structures sizes and shapes affecting surface hydrophobicity are regulated by controlling reaction times and etchant solution concentrations. X-ray diffraction (XRD) analysis is done on a sample before and after of the etching process where patterns indicate that the same compositions present on the sample.

  17. Ethyl coumarin-3-carboxylate: synthesis and chemical properties

    Directory of Open Access Journals (Sweden)

    Bakr F. Abdel-Wahab

    2014-03-01

    Full Text Available Ethyl coumarin-3-carboxylate occupies an important position in the organic synthesis and is used in production of biologically active compounds. Thus, the data published over the last few years on the methods of synthesis and chemical properties of ethyl coumarin-3-carboxylate are reviewed here for the first time. The reactions were classified as coumarin ring reactions and ester group reactions, and some of these reactions have been applied successfully to the synthesis of biologically and industrially important compounds.

  18. Chemical Properties of Paddy Soils in Thailand and Malaysia

    OpenAIRE

    Kai, Hideaki; Masayna, Wittaya; Aibe, Toshiharu; Hamada, Eisuke; Jiraporncharoen, Suchart; Yamada, Yoshio; Vacharotayan, Sorasith; Cholitkul, Wisit; Kanareugsa, Chob

    1981-01-01

    As a part of International Cooperative Studies on the Increasing Productivity of Soils in Tropical Area (1976-1978). chemical properties of paddy soils in Thailand and Malaysia were studied for the purpose of elucidation of the fundamental characteristics of the soils so as to evaluate soil fertility and to implement advanced technical practices for higher production of rice. Each several soil samples were collected from the central, northern, northeastern and southern regions of Thailand and...

  19. Nanostructured conjugated polymers in chemical sensors: synthesis, properties and applications.

    Science.gov (United States)

    Correa, D S; Medeiros, E S; Oliveira, J E; Paterno, L G; Mattoso, Luiz C

    2014-09-01

    Conjugated polymers are organic materials endowed with a π-electron conjugation along the polymer backbone that present appealing electrical and optical properties for technological applications. By using conjugated polymeric materials in the nanoscale, such properties can be further enhanced. In addition, the use of nanostructured materials makes possible miniaturize devices at the micro/nano scale. The applications of conjugated nanostructured polymers include sensors, actuators, flexible displays, discrete electronic devices, and smart fabric, to name a few. In particular, the use of conjugated polymers in chemical and biological sensors is made feasible owning to their sensitivity to the physicochemical conditions of its surrounding environment, such as chemical composition, pH, dielectric constant, humidity or even temperature. Subtle changes in these conditions bring about variations on the electrical (resistivity and capacitance), optical (absorptivity, luminescence, etc.), and mechanical properties of the conjugated polymer, which can be precisely measured by different experimental methods and ultimately associated with a specific analyte and its concentration. The present review article highlights the main features of conjugated polymers that make them suitable for chemical sensors. An especial emphasis is given to nanostructured sensors systems, which present high sensitivity and selectivity, and find application in beverage and food quality control, pharmaceutical industries, medical diagnosis, environmental monitoring, and homeland security, and other applications as discussed throughout this review.

  20. Chemical Composition of the Leaf and Branch Oils of Perymenium grande Hemsl. var. nelsonii (Robins. & Greenm. Fay (Asteraceae-Heliantheae from Costa Rica

    Directory of Open Access Journals (Sweden)

    José F. Cicció

    2012-07-01

    Full Text Available The chemical composition of the essential oils of Perymenium grande Hemsl. var nelsonii (Robins. & Greenm. Fay (Asteraceae growing wild in Costa Rica was analyzed by capillary GC-FID and GC-MS. One hundred and two and one hundred and seven compounds were identified in the leaf and branch oils, respectively, corresponding to about 94.9% and 79.3% of the total amount of the oils. The leaf oil consists mainly of sesquiterpene hydrocarbons (50.3% and monoterpene hydrocarbons (33.8%. The major components of the leaf oil were b -caryophyllene (30.5%, b -pinene (12.4%, germacrene D (10.0%, b -phellandrene (9.8% and a -pinene (8.9%. The branch oil consists mainly of sesquiterpene hydrocarbons (38.3%, monoterpene hydrocarbons (21.6% and oxygenated sesquiterpenes (20.4%. The major components of the branch oil were a -isocomene (13.8%, a -pinene (7.4%, b -isocomene (5.2%, b -pinene (4.3% and b -caryophyllene (4.3%. This is the first report of the chemical composition of the essential oils obtained from this species.

  1. Adulticidal properties of synthesized silver nanoparticles using leaf extracts of Feronia elephantum (Rutaceae) against filariasis, malaria, and dengue vector mosquitoes.

    Science.gov (United States)

    Veerakumar, Kaliyan; Govindarajan, Marimuthu

    2014-11-01

    Mosquito-borne diseases with an economic impact create loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates. Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Extracts from plants may be alternative sources of mosquito control agents because they constitute a rich source of bioactive compounds that are biodegradable into nontoxic products and potentially suitable for use to control mosquitoes. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Feronia elephantum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. The range of concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg mL(-1)) and aqueous leaf extract (40, 80, 120, 160, and 200 μg mL(-1)) were tested against the adults of A. stephensi, A. aegypti, and C. quinquefasciatus. Adults were exposed to varying concentrations of aqueous crude extract and synthesized AgNPs for 24 h. Considerable mortality was evident after the treatment of F. elephantum for all three important vector mosquitoes. The synthesized AgNPs from F. elephantum were highly toxic than crude leaf aqueous extract to three important vector mosquito species. The results were recorded from UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy analysis (EDX), and transmission electron microscopy (TEM). Synthesized AgNPs against the vector mosquitoes A. stephensi, A. aegypti, and C. quinquefasciatus had the following lethal dose (LD)₅₀ and LD₉₀ values: A. stephensi had LD₅₀ and LD₉₀ values of 18

  2. Modification of Textile Materials' Surface Properties Using Chemical Softener

    Directory of Open Access Journals (Sweden)

    Jurgita KOŽENIAUSKIENĖ

    2011-03-01

    Full Text Available In the present study the effect of technological treatment involving the processes of washing or washing and softening with chemical cationic softener "Surcase" produced in Great Britain on the surface properties of cellulosic textile materials manufactured from cotton, bamboo and viscose spun yarns was investigated. The changes in textile materials surface properties were evaluated using KTU-Griff-Tester device and FEI Quanta 200 FEG scanning electron microscope (SEM. It was observed that the worst hand properties and the higher surface roughness are observed of cotton materials if compared with those of bamboo and viscose materials. Also, it was shown that depending on the material structure the handle parameters of knitted materials are the better than the ones of woven fabrics.http://dx.doi.org/10.5755/j01.ms.17.1.249

  3. Biochar physico-chemical properties as affected by environmental exposure.

    Science.gov (United States)

    Sorrenti, Giovambattista; Masiello, Caroline A; Dugan, Brandon; Toselli, Moreno

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30tha(-1). We combined two pycnometry techniques to measure skeletal (ρs) and envelope (ρe) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0-5nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75nm, while no significant changes were measured in the deepest layer, up to 110nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over short (~years) timescales.

  4. Chemical properties of the heavier actinides and transactinides

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1981-01-01

    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f/sup 14/7s/sup 2/7p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable.

  5. BI-LAYER HYBRID BIOCOMPOSITES: CHEMICAL RESISTANT AND PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Mohammad Jawaid,

    2012-02-01

    Full Text Available Bi-layer hybrid biocomposites were fabricated by hand lay-up technique by reinforcing oil palm empty fruit bunch (EFB and jute fibre mats with epoxy matrix. Hybrid composites were prepared by varying the relative weight fraction of the two fibres. The physical (void content, density, dimensional stability, and chemical resistant properties of hybrid composites were evaluated. When the jute fibre loading increased in hybrid composites, physical and chemical resistant properties of hybrid composites were enhanced. Void content of hybrid composites decreased with an increase in jute fibre loading because jute fibres showed better fibre/matrix interface bonding, which leads to a reduction in voids. The density of hybrid composite increased as the quantity of jute fibre loading increased. The hybridization of the jute fibres with EFB composite improved the dimensional stability of the hybrid composites. The performance of hybrid composites towards chemical reagents improved with an increase in jute fibre loading as compared to the EFB composite. The combination of oil palm EFB/jute fibres with epoxy matrix produced hybrid biocomposites material that is competitive to synthetic composites.

  6. New-vista in finding antioxidant and anti-inflammatory property of crude protein extract from Sauropus androgynus leaf.

    Science.gov (United States)

    Madhu, Chakkere Shivamadhu; Manukumar, Honnayakanahalli Marichenne Gowda; Basavaraju, Puttalingaiah

    2014-01-01

    tudy describes antioxidant and anti-inflammatory properties of Sauropus androgynus leaf dialysed protein extract. Free radicals are implicated for many diseases including diabetes mellitus, arthritis, cancer, ageing etc. In the treatment of these diseases, antioxidant therapy has gained utmost importance. The main objective of the present study was to reveal the antioxidant and anti-inflammatory potentiality from S. androgynus leaf dialysed protein extract. The antioxidant and anti-inflammatory properties of S. androgynus studied using different models viz. hydroxyl radical scavenging, DPPH radical scavenging, reducing power assay, superoxide radical scavenging activity by alkaline DMSO and phosphomolybdenum antioxidant assays and in vitro antiinflammatory activity by inhibition of protein denaturation, membrane stabilisation test models carried out. Antioxidant activity was estimated in dose dependent manner showed hydroxyl radical (55.62%), DPPH (50%), reducing power (0.286 Abs), alkaline DMSO (72.51%) and phosphomolybdenum (0.198 Abs) activity high at 50 μg/ml concentration compared to standard curcumin (62.31%), curcumin (56.61%), tannic acid (0.54 Abs), curcumin (75.38%) and vitamin E (0.15 Abs) respectively. In-vitro anti-inflammatory activity by hypotonic induced model showed maximum protection (74.17%) compared to standard Acetylsalcylic acid (86.88%) at 100 μg/ml concentration and also in protein denaturation model protected protein denaturation maximum (83.60%) compared to standard Diclofenac (86.82%) at 100 μg/ml concentration respectively. The antioxidant property usually studied related to the polyphenols and flavonoids present in the extract but present finding concluded that S. androgynus giving hint even potential proteins can also show responsible action effective against free radical mediated disease.

  7. Modeling leaf venation morphogenesis

    CERN Document Server

    Laguna, M F; Jagla, E A

    2007-01-01

    We explore the possibility that the formation of leaf venation patterns is driven by mechanical instabilities in the growing leaf. In contrast to the prevalent canalization hypothesis based on polar auxin transport, mechanical instabilities lead very naturally to hierarchical patterns with an abundant number of closed loops as they exists in almost every leaf venation. We propose a continuum model where the vein formation is driven by a mechanical collapse of the mesophyll layer in the growing leaf, and present a numerical study of this model using a phase field approach. The results show the same qualitative features as real venation patterns and, furthermore, have the same statistical properties.

  8. The chemical composition and antimicrobial activity of the leaf oil of Cupressus lusitanica from Monteverde, Costa Rica.

    Science.gov (United States)

    Hassanzadeh, Sara L; Tuten, Jessika A; Vogler, Bernhard; Setzer, William N

    2010-01-01

    The essential oils from the leaves of three different individuals of Cupressus lusitanica were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. A total of 49 compounds were identified in the leaf oils. The major components of C. lusitanica leaf oil were α-pinene (40%-82%), limonene (4%-18%), isobornyl acetate (up to 10%) and cis-muurola-4(14),5-diene (up to 7%). The essential oil was screened for antimicrobial activity, and it showed antibacterial activity against Bacillus cereus and antifungal activity against Aspergillus niger.

  9. The chemical composition and antimicrobial activity of the leaf oil of Cupressus lusitanica from Monteverde, Costa Rica

    OpenAIRE

    2010-01-01

    The essential oils from the leaves of three different individuals of Cupressus lusitanica were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. A total of 49 compounds were identified in the leaf oils. The major components of C. lusitanica leaf oil were α-pinene (40%-82%), limonene (4%-18%), isobornyl acetate (up to 10%) and cis-muurola-4(14),5-diene (up to 7%). The essential oil was screened for antimicrobial activity, and it showed antibacterial activity...

  10. The chemical composition and antimicrobial activity of the leaf oil of Cupressus lusitanica from Monteverde, Costa Rica

    Directory of Open Access Journals (Sweden)

    Sara L Hassanzadeh

    2010-01-01

    Full Text Available The essential oils from the leaves of three different individuals of Cupressus lusitanica were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. A total of 49 compounds were identified in the leaf oils. The major components of C. lusitanica leaf oil were α-pinene (40%-82%, limonene (4%-18%, isobornyl acetate (up to 10% and cis-muurola-4(14,5-diene (up to 7%. The essential oil was screened for antimicrobial activity, and it showed antibacterial activity against Bacillus cereus and antifungal activity against Aspergillus niger.

  11. Leaf size indices and structure of the peat swamp forest

    Directory of Open Access Journals (Sweden)

    L.G. Aribal

    2017-12-01

    Full Text Available Leaf size indices of the tree species in the peatland of Agusan del Sur in Mindanao in Philippines was examined to deduce the variation of forest structure and observed forest zonation.  Using raunkiaer and webb’s leaf size classification, the leaf morphometrics of seven tree species consistently found on the established sampling plots were determined.  The species includes Ternstroemia philippinensis Merr., Polyscias aherniana Merr. Lowry and G.M. Plunkett, Calophyllum sclerophyllum Vesque, Fagraea racemosa Jack, Ilex cymosa Blume, Syzygium tenuirame (Miq. Merr. and Tristaniopsis micrantha Merr. Peter G.Wilson and J.T.Waterh.The LSI were correlated against the variables of the peat physico-chemical properties (such as bulk density, acrotelm thickness, peat depth, total organic carbon, nitrogen, phosphorus, and potassium, pH; water (pH, ammonium, nitrate, phosphate; and leaf tissue elements (nitrogen, phosphorus and potassium.  Result showed a decreasing leaf size indices and a three leaf size category consisting of mesophyllous, mesophyllous-notophyllous and microphyllous were observed which corresponds to the structure of vegetation i.e., from the tall-pole forest having the biggest average leaf area of 6,142.29 mm2 to the pygmy forest with average leaf area of 1,670.10 mm2.  Such decreased leaf size indices were strongly correlated to soil nitrogen, acrotelm thickness, peat depth, phosphate in water, nitrogen and phosphorus in the plant tissue.

  12. The study of thermodynamic properties and transport properties of multicomponent systems with chemical reactions

    Directory of Open Access Journals (Sweden)

    Samujlov E.

    2013-04-01

    Full Text Available In case of system with chemical reaction the most important properties are heat conductivity and heat capacity. In this work we have considered the equation for estimate the component of these properties caused by chemical reaction and ionization processes. We have evaluated the contribution of this part in heat conductivity and heat capacity too. At the high temperatures contribution in heat conductivity from ionization begins to play an important role. We have created a model, which describe partial and full ionization of gases and gas mixtures. In addition, in this work we present the comparison of our result with experimental data and data from numerical simulation. We was used the data about transport properties of middle composition of Russian coals and the data of thermophysical properties of natural gas for comparison.

  13. C:N:P Stoichiometry and Leaf Traits of Halophytes in an Arid Saline Environment, Northwest China

    Science.gov (United States)

    Wang, Lilong; Zhao, Guanxiang; Li, Meng; Zhang, Mingting; Zhang, Lifang; Zhang, Xinfang; An, Lizhe; Xu, Shijian

    2015-01-01

    Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC), leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry) based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody) to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem. PMID:25798853

  14. C:N:P stoichiometry and leaf traits of halophytes in an arid saline environment, northwest China.

    Directory of Open Access Journals (Sweden)

    Lilong Wang

    Full Text Available Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC, leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem.

  15. C:N:P stoichiometry and leaf traits of halophytes in an arid saline environment, northwest China.

    Science.gov (United States)

    Wang, Lilong; Zhao, Guanxiang; Li, Meng; Zhang, Mingting; Zhang, Lifang; Zhang, Xinfang; An, Lizhe; Xu, Shijian

    2015-01-01

    Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC), leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry) based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody) to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem.

  16. Confocal laser scanning microscopy elucidation of the micromorphology of the leaf cuticle and analysis of its chemical composition.

    Science.gov (United States)

    Nadiminti, Pavani P; Rookes, James E; Boyd, Ben J; Cahill, David M

    2015-11-01

    Electron microscopy techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been invaluable tools for the study of the micromorphology of plant cuticles. However, for electron microscopy, the preparation techniques required may invariably introduce artefacts in cuticle preservation. Further, there are a limited number of methods available for quantifying the image data obtained through electron microscopy. Therefore, in this study, optical microscopy techniques were coupled with staining procedures and, along with SEM were used to qualitatively and quantitatively assess the ultrastructure of plant leaf cuticles. Leaf cryosections of Triticum aestivum (wheat), Zea mays (maize), and Lupinus angustifolius (lupin) were stained with either fat-soluble azo stain Sudan IV or fluorescent, diarylmethane Auramine O and were observed under confocal laser scanning microscope (CLSM). For all the plant species tested, the cuticle on the leaf surfaces could be clearly resolved in many cases into cuticular proper (CP), external cuticular layer (ECL), and internal cuticular layer (ICL). Novel image data analysis procedures for quantifying the epicuticular wax micromorphology were developed, and epicuticular waxes of L. angustifolius were described here for the first time. Together, application of a multifaceted approach involving the use of a range of techniques to study the plant cuticle has led to a better understanding of cuticular structure and provides new insights into leaf surface architecture.

  17. Evaluation and comparison of radical scavenging properties of solvent extracts from Justicia adhatoda leaf using DPPH assay.

    Science.gov (United States)

    Jha, Deepak Kumar; Panda, Likun; Ramaiah, Sudha; Anbarasu, Anand

    2014-12-01

    2,2-Diphenyl-1-picrylhydrazyl (DPPH) method is routinely practiced for the assessment of antioxidant activity of compounds and their mixtures. The method is based on the spectrophotometric measurement of DPPH(·) concentration that changes resulting from the DPPH radical reaction with an antioxidant. The amount of remaining DPPH(·) in the examined system is a measure of the antioxidant activity of compounds. Our study aims at exploring the antioxidant properties of Justicia adhatoda leaf extract and comparing the results in terms of effective concentration which scavenges 50 % radical (EC50). The correlation of the activities for both cold and Soxhlet methanolic extracts is reported with DPPH assay. The antioxidant capacity of the methanolic extract derived by two different methods is positively correlated. Correlation between antioxidant capacity and phenolic content of methanolic extract in both the cases indicates the efficiency of the extraction procedure. Positive correlation and p value <0.05 validate the efficiency of the procedures and results.

  18. Physical-chemical property based sequence motifs and methods regarding same

    Science.gov (United States)

    Braun, Werner [Friendswood, TX; Mathura, Venkatarajan S [Sarasota, FL; Schein, Catherine H [Friendswood, TX

    2008-09-09

    A data analysis system, program, and/or method, e.g., a data mining/data exploration method, using physical-chemical property motifs. For example, a sequence database may be searched for identifying segments thereof having physical-chemical properties similar to the physical-chemical property motifs.

  19. Rheological properties of kaolin and chemically simulated waste

    Energy Technology Data Exchange (ETDEWEB)

    Selby, C.L.

    1981-12-01

    The Savannah River Laboratory is conducting tests to determine the best operating conditions of pumps used to transfer insoluble radioactive sludges from old to new waste tanks. Because it is not feasible to conduct these tests with real or chemically simulated sludges, kaolin clay is being used as a stand-in for the solid waste. The rheology tests described herein were conducted to determine whether the properties of kaolin were sufficiently similar to those of real sludge to permit meaningful pump tests. The rheology study showed that kaolin can be substituted for real waste to accurately determine pump performance. Once adequately sheared, kaolin properties were found to remain constant. Test results determined that kaolin should not be allowed to settle more than two weeks between pump tests. Water or supernate from the waste tanks can be used to dilute sludge on an equal volume basis because they identically affect the rheological properties of sludge. It was further found that the fluid properties of kaolin and waste are insensitive to temperature.

  20. MORPHOLOGICAL AND CHEMICAL PROPERTIES OF SELECTED SWEET VIOLET POPULATIONS

    Directory of Open Access Journals (Sweden)

    Renata ERHATIĆ

    2010-10-01

    Full Text Available Sweet violet (Viola odorata L. blooms in continental climate conditions in early spring (March-April with delicate flowers of attractive scent because of which it is frequently gathered from its natural habitats. Differences among the populations were established according to their morphological properties of twelve populations from Križevci area. Stated information indicates that the populations gathered from meadow – habitat are shorter and have a smaller diameter than the populations gathered from the habitat in forest, whereas the population from the orchards has the highest number of leaves and flowers. Correlation analysis shows strong (P<0.01 positive connection of the root mass, leaves mass, number of leaves with the total mass of the plants, as well as connection of the plant mass with the number of flowers. Chemical analysis established agrochemical soil properties and nutrient concentrations in plants. Correlations between the examined properties of violets and soil properties indicate that the potassium concentration in the roots is in strong (P <0.01 correlation with potassium in the soil, whereas phosphorus concentration in flower is in a considerably strong (P<0.05 positive correlation with the phosphorus in the soil.

  1. Study of Aerosol Chemical Composition Based on Aerosol Optical Properties

    Science.gov (United States)

    Berry, Austin; Aryal, Rudra

    2015-03-01

    We investigated the variation of aerosol absorption optical properties obtained from the CIMEL Sun-Photometer measurements over three years (2012-2014) at three AERONET sites GSFC; MD Science_Center and Tudor Hill, Bermuda. These sites were chosen based on the availability of data and locations that can receive different types of aerosols from land and ocean. These absorption properties, mainly the aerosol absorption angstrom exponent, were analyzed to examine the corresponding aerosol chemical composition. We observed that the retrieved absorption angstrom exponents over the two sites, GSFC and MD Science Center, are near 1 (the theoretical value for black carbon) and with low single scattering albedo values during summer seasons indicating presence of black carbon. Strong variability of aerosol absorption properties were observed over Tudor Hill and will be analyzed based on the air mass embedded from ocean side and land side. We will also present the seasonal variability of these properties based on long-range air mass sources at these three sites. Brent Holben, NASA GSFC, AERONET, Jon Rodriguez.

  2. The physical and chemical properties of ultrathin oxide films.

    Science.gov (United States)

    Street, S C; Xu, C; Goodman, D W

    1997-01-01

    Thin oxide films (from one to tens of monolayers) of SiO2, MgO, NiO, Al2O3, FexOy, and TiO2 supported on refractory metal substrates have been prepared by depositing the oxide metal precursor in a background of oxygen (ca 1 x 10(-5) Torr). The thinness of these oxide samples facilitates investigation by an array of surface techniques, many of which are precluded when applied to the corresponding bulk oxide. Layered and mixed binary oxides have been prepared by sequential synthesis of dissimilar oxide layers or co-deposition of two different oxides. Recent work has shown that the underlying oxide substrate can markedly influence the electronic and chemical properties of the overlayer oxide. The structural, electronic, and chemical properties of these ultrathin oxide films have been probed using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), electron energy loss spectroscopy (ELS), ion-scattering spectroscopy (ISS), high-resolution electron energy loss spectroscopy (HREELS), infrared reflectance absorption spectroscopy (IRAS), temperature-programmed desorption (TPD), scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS).

  3. Chemical composition and surface charge properties of montmorillonite

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-wen; HU Min; HU Yue-hua

    2008-01-01

    The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point(IEP) of the montmorillonite shows positive correlation with the mass fractions of Fe2O3 and K20, but it has little relation to the mass fractions of other chemical compositions. At around pH=6.8, the surface zeta potential of the montmorillonite shows the negative relationship with the mass fractions of Fe2O3 and MgO, but it does not linearly correlate to the mass fractions of other chemical compositions. Cell parameter(b0) of the montmofillonite expresses negative linear relationship with mass fractions of K2O and Na2O, so does c0sinβ with mass fractions of SiO2 and Fe2O3. And there is no specific relationship between bo and IEP of different montmori Uonites, but there is positive correlation between c0sinβ and IEP of different montmorillonite samples.

  4. Theoretical investigation of chemical and physical properties of gaseous fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, Fredrik

    1999-12-01

    This thesis is discussing the chemical and physical properties of different gaseous fuels. A mapping of about seventy gaseous fuels resulted in eleven type gases, these gases have mainly five components (inerts, H{sub 2}, CO, CH{sub 4} and higher order of hydrocarbons) of different quantities. Calculations of heating value and Wobbe number have been done. Dew point temperatures have been estimated by using three different programs. Flammability limits, laminar flame speed and auto ignition temperatures have been calculated by using a kinetic and chemical program developed by Mauss. Flammability limits have been compared with Le Chatelier's law and measurements. Problems related to combustion such as flash back, lift off and instability are closely connected with flame speed and flow patterns. These problems are discussed in terms of laminar flame speed and Reynolds' number. The main results of this study were: Auto ignition temperature for gas mixtures behavior is very complex and unpredictable. In general small quantities of hydrogen decrease the temperature of auto ignition. The calculations of flammability limits by the kinetic and chemical software showed good agreement to measurements. Low Btu gases requires large flow area in order to avoid large pressure drop.

  5. Chemical properties of two-year-old deciduous species

    Energy Technology Data Exchange (ETDEWEB)

    Chow, P.; Rolfe, G.L.; Lee, C.S.; White, T.A.

    1983-01-01

    Contents of ash, hot-water extractives, 1% sodium hydroxide extractives, alcohol-benzene extractive, lignin, holocellulose, alpha-cellulose, and pentosan were determined on two-year-old, short-rotation trees of autumn olive, black alder, black locust, eastern cottonwood, royal paulownia, silver maple, and sycamore. These plantations were established in 1978 on marginal agricultural land that was not suitable for food production in Illinois. Six comparable species of commercial lumber were also analyzed. Test results indicated that all chemical properties did vary with species, above-ground tree portions, and ages of species. The two-year-old juvenile trees had higher average extractives, holocellulose, pentosan, and ash content than did the lumber of matured wood. Black locust possessed the highest values of holocellulose and alpha-cellulose, while the eastern cottonwood had the highest extractive contents. Silver maple had the highest lignin content. Both bark and branches which consisted of about 32% of the mass weight of young trees, had a higher average lignin, extractive and ash content than those of the stemwood. Based on chemical composition, these seven juvenile deciduous species could serve as a raw material for the paper and chemical industries, as well as for energy. 19 references, 8 figures, 6 tables.

  6. Studies on the anti-asthmatic and antitussive properties of aqueous leaf extract of Bryophyllum pinnatum in rodent species

    Institute of Scientific and Technical Information of China (English)

    Edward O Salami; Raymond I Ozolua; Stephen O Okpo; Gerald I Eze; Dickson O Uwaya

    2013-01-01

    Objective: To evaluate the antiasthmatic and antitussive properties of the aqueous leaf extract of Bryophyllum pinnatum (B. pinnatum) (BP) Lam. Methods: Ovalbumin-sensitized guinea pigs which were treated with BP for 21 consecutive days were exposed to 0.2% histamine aerosol in a glass chamber. Mucus viscosity, white blood cell and lymphocyte counts and tracheal wall morphometry were measured. Bouts of cough were counted pre and post acute exposure of extract-treated (×7 d) guinea pigs to 7.5% citric acid aerosol in a chamber. Phenol red expectoration was estimated in mice after 7 d of daily administration of BP. Results: Doses of 200 and 400 mg/kg/day (×21 d) BP significantly increased the time for guinea pigs to experience preconvulsive dyspnoea. BP and salbutamol (0.5 mg/kg/day × 21 d) reduced mucus viscosity in the sensitized group to values comparable with controls. White blood cell, lymphocyte counts and tracheal morphometry were not significantly altered. Both doses of BP also significantly reduced the bouts of cough but only 400 mg/kg/day significantly inhibited the amount of phenol red secreted. Conclusions: BP has demonstrated antiasthmatic and antitussive properties in these rodent models. These properties may underscore its use in Nigerian ethnomedicine.

  7. EFFECT OF ALTERNATIVE MULTINUTRIENT SOURCES ON SOIL CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Vanessa Martins

    2015-02-01

    Full Text Available The current high price of potassium chloride and the dependence of Brazil on imported materials to supply the domestic demand call for studies evaluating the efficiency of alternative sources of nutrients. The aim of this work was to evaluate the effect of silicate rock powder and a manganese mining by-product, and secondary materials originated from these two materials, on soil chemical properties and on brachiaria production. This greenhouse experiment was conducted in pots with 5 kg of soil (Latossolo Vermelho-Amarelo distrófico - Oxisol. The alternative nutrient sources were: verdete, verdete treated with NH4OH, phonolite, ultramafic rock, mining waste and the proportion of 75 % of these K fertilizers and 25 % lime. Mixtures containing 25 % of lime were heated at 800 ºC for 1 h. These sources were applied at rates of 0, 150, 300, 450 and 600 kg ha-1 K2O, and incubated for 45 days. The mixtures of heated silicate rocks with lime promoted higher increases in soil pH in decreasing order: ultramafic rock>verdete>phonolite>mining waste. Applying the mining waste-lime mixture increased soil exchangeable K, and available P when ultramafic rock was incorporated. When ultramafic rock was applied, the release of Ca2+ increased significantly. Mining subproduct released the highest amount of Zn2+ and Mn2+ to the soil. The application of alternative sources of K, with variable chemical composition, altered the nutrient availability and soil chemical properties, improving mainly plant development and K plant uptake, and are important nutrient sources.

  8. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  9. Chemical Modification Effect on the Mechanical Properties of Coir Fiber

    Directory of Open Access Journals (Sweden)

    Samia Sultana Mir

    2012-04-01

    Full Text Available Natural fiber has a vital role as a reinforcing agent due to its renewable, low cost, biodegradable, less abrasive and eco-friendly nature. Whereas synthetic fibers like glass, boron, carbon, metallic, ceramic and inorganic fibers are expensive and not eco-friendly. Coir is one of the natural fibers easily available in Bangladesh and cheap. It is derived from the husk of the coconut (Cocos nucifera. Coir has one of the highest concentrations of lignin, which makes it stronger. In recent years, wide range of research has been carried out on fiber reinforced polymer composites [4-13].The aim of the present research is to characterize brown single coir fiber for manufacturing polymer composites reinforced with characterized fibers. Adhesion between the fiber and polymer is one of factors affecting the strength of manufactured composites. In order to increase the adhesion, the coir fiber was chemically treated separately in single stage (with Cr2(SO43•12(H2O and double stages (with CrSO4 and NaHCO3. Both the raw and treated fibers were characterized by tensile testing, Fourier transform infrared (FTIR spectroscopic analysis, scanning electron microscopic analysis. The result showed that the Young’s modulus increased, while tensile strength and strain to failure decreased with increase in span length. Tensile properties of chemically treated coir fiber was found higher than raw coir fiber, while the double stage treated coir fiber had better mechanical properties compared to the single stage treated coir fiber. Scanning electron micrographs showed rougher surface in case of the raw coir fiber. The surface was found clean and smooth in case of the treated coir fiber. Thus the performance of coir fiber composites in industrial application can be improved by chemical treatment.

  10. Meteorology. Subvol. b. Physical and chemical properties of the air

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G. (ed.); Bakan, S.; Hinzpeter, H. (Max-Planck-Institut fuer Meteorologie, Hamburg (Germany, F.R.)); Hoeller, H. (Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V. (DFVLR), Wessling (Germany, F.R.). Inst. fuer Physik der Atmosphaere); Jaenicke, R. (Mainz Univ. (Germany, F.R.). Inst. fuer Meteorologie); Jeske, H. (Hamburg Univ. (Germany, F.R.). Meteorologisches Inst.); Laube, M. (Koeln Univ. (Germany, F.R.). Inst. fuer Geophysik und Meteorologie); Volland, H. (Bonn Univ. (Germany, F.R.). Radioastronomisches Inst.); Warneck, P.; Wurzinger, C. (Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut), Mainz (Germany, F.R.))

    1988-01-01

    Regarding the physical properties, Chapter 5 'Cloud physics' describes the principles and parameters governing the complex mechanisms of cloud formation and precipitation. Further, the field of electromagnetic wave propagation in the atmosphere is discussed. Because of their relevance to climate, the two parts of the spectrum mentioned in Chapter 6 'Atmospheric radiation' deserve special attention; they cover the solar radiative flux into the atmosphere (wavelengths 0.3 ... 4 ..mu..m) and the terrestrial outgoing radiation (wavelengths 4 ... 60 ..mu..m). In this domain the interaction of radiation with the chemical constituents and admixtures of the atmosphere as well as the interaction with clouds are important. Radiation is tightly related to the optical properties of the atmosphere and to radiometeorology concerned with the propagation of radiowaves (wavelengths 1 mm ... 10 m) which depends on meteorological conditions. 'Atmospheric electricity' is presented in Chapter 8, where data and information on the sources and sinks of the quasi-static atmospheric electric field, the role of thunderstorm activity, the global ring current and low-frequency electromagnetic waves are discussed. Data on the effects of aerosols, i.e. admixtures of gaseous, liquid or solid phase organic or non-organic matter, is given in Chapter 9 'Aerosol physics and chemistry' which has a close connection to Chapter 5. The last contribution, Chapter 10 'Chemical composition of and chemical reactions in the atmosphere' particularly discusses trace gases, which, similar to aerosols, despite their low concentration have a large impact on climate. Changes of the concentration of trace gases may be caused by anthropogenic influences and were found to have done so already.

  11. Effects of scalp dermatitis on chemical property of hair keratin

    Science.gov (United States)

    Kim, Kyung Sook; Shin, Min Kyung; Park, Hun-Kuk

    2013-05-01

    The effects of scalp dermatitis (seborrheic dermatitis (SD), psoriasis, and atopic dermatitis (AD)) on chemical properties of hair keratin were investigated by Fourier transform infrared (FT-IR) spectroscopy. Hairs were collected from lesional regions affected by SD, psoriasis, and AD and non-lesional regions separately. The hairs with SD were taken from patients with ages of 16-80 years. The ages of patients with psoriasis ranged from 8 to 67 years, and all patients exhibited moderate disease. Hairs with AD were taken from the patients with ages of 24-45 years and the average SCORing atopic dermatitis (SCORAD) was 48.75. Hairs from 20 normal adults were collected as a control. The FT-IR absorbance bands were analyzed by the Gaussian model to obtain the center frequency, half width, height, and area of each band. The height and area of all bands in the spectra were normalized to the amide I centered at 1652 cm-1 to quantitatively analyze the chemical composition of keratin. The spectra of hair with scalp dermatitis were different with that of control, the amide A components centered at 3278 cm-1 were smaller than those of the control. The psoriasis hair showed a large difference in the IR absorbance band between lesional and non-lesional hairs indicating good agreement with the morphological changes. The hairs with diseases did not show differences in the content of cystine, which was centered at 1054 cm-1, from the control. The chemical properties of keratin were not significantly different between the hairs affected by SD, psoriasis, and AD. However, the changes induced by scalp dermatitis were different with weathering. Therefore, FT-IR analysis could be used to screen differences between the physiological and pathological conditions of scalp hair.

  12. Biochar physico-chemical properties as affected by environmental exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sorrenti, Giovambattista, E-mail: g.sorrenti@unibo.it [Department of Agricultural Sciences, University of Bologna, viale G. Fanin 44, 40127 Bologna (Italy); Masiello, Caroline A., E-mail: masiello@rice.edu [Departments of Earth Science, BioSciences, and Chemistry, Rice University, Houston, TX 77005 (United States); Dugan, Brandon, E-mail: dugan@rice.edu [Department of Earth Science, Rice University, Houston, TX 77005 (United States); Toselli, Moreno, E-mail: moreno.toselli@unibo.it [Department of Agricultural Sciences, University of Bologna, viale G. Fanin 44, 40127 Bologna (Italy)

    2016-09-01

    To best use biochar as a sustainable soil management and carbon (C) sequestration technique, we must understand the effect of environmental exposure on its physical and chemical properties because they likely vary with time. These properties play an important role in biochar's environmental behavior and delivery of ecosystem services. We measured biochar before amendment and four years after amendment to a commercial nectarine orchard at rates of 5, 15 and 30 t ha{sup −1}. We combined two pycnometry techniques to measure skeletal (ρ{sub s}) and envelope (ρ{sub e}) density and to estimate the total pore volume of biochar particles. We also examined imbibition, which can provide information about soil hydraulic conductivity. Finally, we investigated the chemical properties, surface, inner layers atomic composition and C1s bonding state of biochar fragments through X-ray photoelectron spectroscopy (XPS). Ageing increased biochar skeletal density and reduced the water imbibition rate within fragments as a consequence of partial pore clogging. However, porosity and the volume of water stored in particles remained unchanged. Exposure reduced biochar pH, EC, and total C, but enhanced total N, nitrate-N, and ammonium-N. X-ray photoelectron spectroscopy analyses showed an increase of O, Si, N, Na, Al, Ca, Mn, and Fe surface (0–5 nm) atomic composition (at%) and a reduction of C and K in aged particles, confirming the interactions of biochar with soil inorganic and organic phases. Oxidation of aged biochar fragments occurred mainly in the particle surface, and progressively decreased down to 75 nm. Biochar surface chemistry changes included the development of carbonyl and carboxylate functional groups, again mainly on the particle surface. However, changes were noticeable down to 75 nm, while no significant changes were measured in the deepest layer, up to 110 nm. Results show unequivocal shifts in biochar physical and chemical properties/characteristics over

  13. Tree species traits influence soil physical, chemical, and biological properties in high elevation forests.

    Directory of Open Access Journals (Sweden)

    Edward Ayres

    Full Text Available BACKGROUND: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. METHODOLOGY/PRINCIPAL FINDINGS: We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N concentration and lowest lignin:N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid

  14. Antioxidant and antimicrobial properties of Moltkia petraea (Tratt.) Griseb. flower, leaf and stem infusions.

    Science.gov (United States)

    Koncić, M Zovko; Kremer, D; Gruz, J; Strnad, M; Bisevac, G; Kosalec, I; Samec, D; Piljac-Zegarac, J; Karlović, K

    2010-06-01

    Antioxidant and antimicrobial activities as well as the quantity of phenolic substances (total phenol, flavonoid and phenolic acid contents) were determined in aqueous extracts of leaves, stems and flowers of Moltkia petraea (Tratt.) Griseb. from two mountainous localities (Sveti Jure and Snijeznica) in Croatia. In addition, the profile of phenolic acids was analyzed by UPLC-MS/MS. Antioxidant activities of all extracts in different test systems, namely the DPPH radical scavenging, reducing power assay and chelating activity, increased with extract concentration. Activity of the extracts from Snijeznica in beta-carotene-linoleic acid assay did not differ from the activity of standard, BHA. The leaf extracts from Snijeznica demonstrated superior antioxidant activity in most of the assays, while the stem extract from the same locality was the most effective Fe(2+) ion chelator. In general, the extracts from Snijeznica were more effective antioxidants than the corresponding extracts from Sveti Jure. The aqueous extracts of M. petraea did not show antimicrobial activity against bacteria and fungi tested in the diffusion and dilution assays. Copyright 2010 Elsevier Ltd. All rights reserved.

  15. Effects of simulated acid rain on leaf cuticular characteristics and surface properties

    Energy Technology Data Exchange (ETDEWEB)

    Percy, K.E.

    1987-01-01

    The effects of simulated acid rain (SAR) on adaxial leaf cuticles were investigated for a group of plant species selected from commercially-important crops and trees which exhibited markedly different cuticular characteristics. Expanding leaves of controlled-environment grown plants were exposed from emergence to full expansion to pH 5.6, 4.6, 4.2, 3.8, 3.4, 3.0 or 2.6 simulated rain (SAR) applied at 2 mm/h on alternate days. The number of events, the amount, droplet size and velocity were representative of UK ambient rainfall characteristics. The non-acidic pH 5.6 simulated rain consisted of 14 inorganic ions in weight/volume concentrations equivalent to those measured at a site in Eastern Canada. The degree of foliar injury and size of lesions was greater on crop species with waxy leaves than those with non-waxy leaves. Injury was least on needles of Sitka spruce (Picea sitchensis (Bong.) Carr.). The relative sensitivity of the species examined to foliar injury decreased in the order: field rap (Brassica napus L.) > Eucalyptus globulus L.) > pea (Pisum sativum L.) > dwarf bean (Phaseolus vulgaris L.) > field bean (Vicia faba L.) > Sitka spruce.

  16. Effects of temperature and solvent on antioxidant properties of curry leaf (Murraya koenigii L.).

    Science.gov (United States)

    Sasidharan, Indu; Menon, A Nirmala

    2011-06-01

    Total polyphenol content (TPC) and antioxidant activities of curry leaf extracts (hexane, chloroform, ethanol, ethanol-water (1:1) and water at ambient (AT, 25 °C) and boiling temperature (BT) (Soxhlet extraction), were determined by DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt), and total reductive potential assays. TPC was in the order ethanol-water (1:1) (AT) > water (AT) > chloroform (AT) > ethanol-water (1:1) (BT) > hexane (AT) > ethanol (BT) > water (BT) > hexane (BT). Ethanol-water (AT) had the maximum TPC of 501 ± 4.6 mg/g GAE and 82% radical scavenging activity (RSA) at 10 μg/ml level (DPPH) and 100% RSA (ABTS) at 10 μg/ml and at hot conditions (ethanol-water (BT)) had less TPC (28.7 ± 0.9%), and 43% RSA by DPPH and 53.6% by ABTS assays. Hot extracts had lesser antioxidant activities than ambient extracts. The best solvent system for getting maximum antioxidant activity from curry leaves was ethanol-water (1:1)-(AT).

  17. Antibacterial activity, chemical composition, and cytotoxicity of leaf's essential oil from Brazilian pepper tree (Schinus terebinthifolius, Raddi

    Directory of Open Access Journals (Sweden)

    A.B. Silva

    2010-03-01

    Full Text Available The antibacterial potential of leaf's essential oil (EO from Brazilian pepper tree (Schinus terebinthifolius Raddi against staphylococcal isolates from dogs with otitis externa was evaluated. The minimum inhibitory concentration of EO ranged from 78.1 to 1,250 fg/mL. The oil was analyzed by GC and GC/MS and cytotoxicity tests were carried out with laboratory animals.

  18. Chemical composition of essential oil and leaf anatomy of Salvia bertolonii Vis. and Salvia pratensis L. (Sect. Plethiosphace, Lamiaceae).

    Science.gov (United States)

    Anackov, Goran; Bozin, Biljana; Zorić, Lana; Vukov, Dragana; Mimica-Dukić, Neda; Merkulov, Ljiljana; Igić, Ruzica; Jovanović, Marina; Boza, Pal

    2008-12-23

    The taxonomical relationship between Salvia pratensis and S. bertolonii has been unclear for a long time. Salvia bertolonii has alternatively been considered a synonym, a subspecies, a problematic subspecies and a form of Salvia pratensis. However, both these two species are sometimes used in traditional medicine instead of sage (Salvia officinalis) or as an adulteration for the same drug. In order to confirm the status of S. bertolonii, together with the potential identification characteristics for differentiation from sage, both taxa were analyzed through the analysis of their essential oils, together with the micromorphological characteristics of the leaf surface and the anatomy and morphology of the leaves. The obtained results show that there are clear differences in the quantity of essential oil (0.073% for S. pratensis and 0.0016% for S. berolonii). The major compound in the essential oil of S. pratensis was E-caryophyllene (26.4%) while in S. berolonii essential oil caryophyllene oxide was the major component (35.1%). The micromorphological differences are also pronounced in the leaf indumentum (density and distribution of certain types of non-glandular and glandular trichomes). Clear distinction between the investigated Salvia species is also observed in the leaf anatomy (in S. pratensis leaves are thinner, palisade tissue is made of 1-2 layers of cells, and leaves of S. bertolonii are characterized by 2-3 layers of palisade tissue cells, and consequently thicker).

  19. Chemical Composition of Essential Oil and Leaf Anatomy of Salvia bertolonii Vis. and Salvia pratensis L. (Sect. Plethiosphace, Lamiaceae

    Directory of Open Access Journals (Sweden)

    Pal Boža

    2008-12-01

    Full Text Available The taxonomical relationship between Salvia pratensis and S. bertolonii has been unclear for a long time. Salvia bertolonii has alternatively been considered a synonym, a subspecies, a problematic subspecies and a form of Salvia pratensis. However, both these two species are sometimes used in traditional medicine instead of sage (Salvia officinalis or as an adulteration for the same drug. In order to confirm the status of S. bertolonii, together with the potential identification characteristics for differentiation from sage, both taxa were analyzed through the analysis of their essential oils, together with the micromorphological characteristics of the leaf surface and the anatomy and morphology of the leaves. The obtained results show that there are clear differences in the quantity of essential oil (0.073% for S. pratensis and 0.0016% for S. berolonii. The major compound in the essential oil of S. pratensis was E-caryophyllene (26.4% while in S. berolonii essential oil caryophyllene oxide was the major component (35.1%. The micromorphological differences are also pronounced in the leaf indumentum (density and distribution of certain types of non-glandular and glandular trichomes. Clear distinction between the investigated Salvia species is also observed in the leaf anatomy (in S. pratensis leaves are thinner, palisade tissue is made of 1-2 layers of cells, and leaves of S. bertolonii are characterized by 2-3 layers of palisade tissue cells, and consequently thicker.

  20. Soil chemical properties and nutrients in maize fertilized with urban waste compost

    Directory of Open Access Journals (Sweden)

    José Ricardo Mantovani

    2017-06-01

    Full Text Available Urban waste compost has a potential to be used as an organic fertilizer in agriculture, but field studies are required to define the recommendable rates for crops. This study aimed at evaluating the effect of fertilization with urban waste compost on the soil chemical properties, yield, nutrient and heavy metal contents, in maize leaves and grains. The field experiment was carried out in a randomized complete block design, with seven treatments and four replications. The treatments consisted of six urban waste compost doses (0 Mg ha-1, 5 Mg ha-1, 10 Mg ha-1, 20 Mg ha-1, 30 Mg ha-1 and 40 Mg ha-1, applied in the planting furrow, plus an additional control treatment, with NPK mineral fertilization and no waste compost application. Fertilization with up to 40 Mg ha-1 of urban waste compost improves soil fertility. Fertilization with urban waste compost increases grain yield and the N, P and K contents in leaf tissue and maize grains, without inducing plant contamination with heavy metals. The application of 30 Mg ha-1 of urban waste compost can replace mineral fertilization in maize cultivation.

  1. Extraction and Antibacterial Properties of Thyme Leaf Extracts: Authentic Practice of Green Chemistry

    Science.gov (United States)

    Purcell, Sean C.; Pande, Prithvi; Lin, Yingxin; Rivera, Ernesto J.; Paw U, Latisha; Smallwood, Luisa M.; Kerstiens, Geri A.; Armstrong, Laura B.; Robak, MaryAnn T.; Baranger, Anne M.; Douskey, Michelle C.

    2016-01-01

    In this undergraduate analytical chemistry experiment, students quantitatively assess the antibacterial activity of essential oils found in thyme leaves ("Thymus vulgaris") in an authentic, research-like environment. This multi-week experiment aims to instill green chemistry principles as intrinsic to chemical problem solving. Students…

  2. Extraction and Antibacterial Properties of Thyme Leaf Extracts: Authentic Practice of Green Chemistry

    Science.gov (United States)

    Purcell, Sean C.; Pande, Prithvi; Lin, Yingxin; Rivera, Ernesto J.; Paw U, Latisha; Smallwood, Luisa M.; Kerstiens, Geri A.; Armstrong, Laura B.; Robak, MaryAnn T.; Baranger, Anne M.; Douskey, Michelle C.

    2016-01-01

    In this undergraduate analytical chemistry experiment, students quantitatively assess the antibacterial activity of essential oils found in thyme leaves ("Thymus vulgaris") in an authentic, research-like environment. This multi-week experiment aims to instill green chemistry principles as intrinsic to chemical problem solving. Students…

  3. Chemical and physical properties of opencast lignite minesoils

    Energy Technology Data Exchange (ETDEWEB)

    Varela, C.; Vazquez, C.; Gonzalez-Sangregorio, M.V.; Leiros, M.C.; Gil-Sotres, F. (Facultad de Farmacia de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Edafologia y Quimica Agricola)

    1993-09-01

    The evolution of chemical and physical properties in a series of mine soils aged between 0 and 5 years, developed from spoil materials of the Meirama opencast lignite mine in Galicia (NW Spain), was studied. The soils are recovered without use of topsoil and are subject to identical management. In the surface horizon (0-7 cm), total C and N, CEC, and pyrophosphate-extracted Al[sub 2]O[sub 3] and Fe[sub 2]O[sub 3] increased with soil age. Oxalic-oxalate-extracted Al[sub 2]O[sub 3] and Fe[sub 2]O[sub 3] on the other hand, increased with soil age in all the horizons studied. Rapid recovery in terms of physical properties was also observed: bulk density dropped, while total porosity, percentage of macropores, and hydraulic conductivity increased, and aggregates showed greater stability on immersion in water. The results indicate that mineral weathering and organometallic complexation are the dominant processes at these early stages of edaphogenesis and that properties associated with gas exchange showed more rapid development than those associated with water movement. In spite of the above rapid modifications, the characteristics of the oldest soils in the series were still very different from those of native Galician soils.

  4. Physical and chemical properties of two Iranian peat types

    Directory of Open Access Journals (Sweden)

    M.A. Rahgozar

    2015-09-01

    Full Text Available Because peat has high organic content and high natural water content, it is potentially problematic for civil engineering projects involving construction on peatland. Therefore, it is important to understand the physical, chemical and geotechnical properties of the peat. The aim of the study reported here was to investigate the properties of two Iranian peat types. Peat and water samples were collected from sites within two extensive wetland areas (Chaghakhor Wetland and Gavkhuni Swamp where construction works are planned. Both sites had peat layers more than three metres thick, which were sampled at depths of 0.6, 1.2, 1.8, 2.4 and 3.0 metres below ground level with four replicates per site. Degree of humification was determined in the field. Laboratory tests were conducted to determine the pH of water and peat; and the natural (field moisture content, organic content, ash content, bulk density, dry density, density of solids, liquid limit, initial void ratio, linear shrinkage, unconfined compressive strength, shear strength and falling-head permeability of each peat sample. We also investigated the elemental compositions and microstructure of the peats using X-Ray fluorescence and scanning electron microscopy. The laboratory tests of physical and geotechnical properties indicated that, for construction purposes, Chaghakhor peat is weaker than Gavkhuni peat.

  5. Evaluation of the acute toxicity, phytochemical constituents and anti - ulcer properties of methanolic leaf extract of Annona muricata in mice

    Directory of Open Access Journals (Sweden)

    Valentine Uneojo Omoja

    2014-02-01

    Full Text Available This study investigated the acute toxicity, phytochemical constituents and anti - ulcer properties of methanolic leaf extract of Annona muricata in mice. The anti - ulcer activity was evaluated using absolute ethanol-induced ulcer and aspirin-induced ulcer models in mice. An LD50 of 354.8 +/- 8 mg/kg body weight, bw of the extract was obtained on oral administration. Investigation of the phytochemical constituents of the plant extract revealed the presence of saponins, alkaloids and traces of tannins. All doses of the extract (50, 75 and 100 mg/kg used for the study significantly reduced (p<0.05 the mean number of ulcers in both ulcer models when compared to the untreated group A (10 ml/kg distil water. Optimum antiulcer activity of the extract against absolute ethanol-induced ulcer was noted at 50 mg/kg bw. At this 50 mg/kg, the mean number of ulcers and mean ulcer index of the extract was significantly lower (p<0.05 than that of Cimetidine at 100 mg/kg (3.60 +/- 0.51: 5.00 +/- 0.32; 1.5+/-0.05: 0.98+/-0.03, the treated control group whereas the protective index of the extract was higher than that of cimetidine (50.51 %: 24.24 %. The results obtained from this study strongly suggest that methanolic leaf extract of Annona muricata can be effectively used for the treatment of ulcer in low doses and can provide better therapeutic effect than cimetidine if used in ulcers caused by alcoholism and related agents. [J Intercult Ethnopharmacol 2014; 3(1.000: 37-43

  6. Impacts of microbial activity on the optical and copper-binding properties of leaf-litter leachate

    Directory of Open Access Journals (Sweden)

    Chad eCuss

    2012-05-01

    Full Text Available Dissolved organic matter (DOM is a universal part of all aquatic systems that largely originates with the decay of plant and animal tissue. Its polyelectrolytic and heterogeneous characters make it an effective metal-complexing agent with highly diverse characteristics. Microbes utilize DOM as a source of nutrients and energy and their enzymatic activity may change its composition, thereby altering the bioavailability and toxicity of metals. This study investigated the impacts of microbial inoculation upon the optical and copper-binding properties of freshly-produced leaf-litter leachate over 168 hours. Copper speciation was measured using voltammetry, and using fluorescence quenching analysis of independent fluorophores determined using parallel factor analysis (PARAFAC. Four distinct components were detected. Thirty-five percent of total protein/polyphenol-like fluorescence was removed after 168-hr of exposure to riverine microbes. Using voltammetry, a 6-fold increase in copper-complexing (CC capacity (130 - 770 μmol Cu/g C was observed over the exposure period, while the conditional binding constant (log K decreased from 7.2 to 5.8. Binding parameters were significantly different for all four PARAFAC components and were generally in agreement with voltammetric results in the microbially-degraded samples, but they were significantly different in leachate. These results suggest that non-fluorescent moieties may exert a significant influence upon binding characteristics. Three of four binding sites corresponding to independent PARAFAC components, which had distinct characteristics in the leachate, retained significantly different log K values (p<0.05 after 168 hours of incubation, while their complexing capacities became similar. It was concluded that the microbial metabolization of maple leaf leachate has a significant impact upon DOM composition and its copper-binding characteristics.

  7. Impacts of microbial activity on the optical and copper-binding properties of leaf-litter leachate.

    Science.gov (United States)

    Cuss, Chad W; Guéguen, Celine

    2012-01-01

    Dissolved organic matter (DOM) is a universal part of all aquatic systems that largely originates with the decay of plant and animal tissue. Its polyelectrolytic and heterogeneous characters make it an effective metal-complexing agent with highly diverse characteristics. Microbes utilize DOM as a source of nutrients and energy and their enzymatic activity may change its composition, thereby altering the bioavailability and toxicity of metals. This study investigated the impacts of microbial inoculation upon the optical and copper-binding properties of freshly produced leaf-litter leachate over 168 h. Copper speciation was measured using voltammetry, and using fluorescence quenching analysis of independent fluorophores determined using parallel factor analysis (PARAFAC). Two protein/polyphenol-like and two fulvic/humic-like components were detected. Thirty-five percent of total protein/polyphenol-like fluorescence was removed after 168-h of exposure to riverine microbes. The microbial humic-like and tryptophan-like PARAFAC components retained significantly different log K values after 168 h of incubation (p complexing capacities were similar. Using voltammetry, a sixfold increase in copper-complexing capacity (CC, from 130 to 770 μmol Cu g C(-1)) was observed over the exposure period, while the conditional binding constant (log K) decreased from 7.2 to 5.8. Overall binding parameters determined using voltammetry and fluorescence quenching were in agreement. However, the electrochemically based binding strength was significantly greater than that exhibited by any of the PARAFAC components, which may be due to the impact of non-fluorescent DOM, or differences in the concentration ranges of metals analyzed (i.e., different analytical windows). It was concluded that the microbial metabolization of maple leaf leachate has a significant impact upon DOM composition and its copper-binding characteristics.

  8. Variations of leaf N, P concentrations in shrubland biomes across northern China: phylogeny, climate and soil

    Directory of Open Access Journals (Sweden)

    X. Yang

    2015-11-01

    Full Text Available Concentrations of leaf nitrogen (N and phosphorus (P are key leaf traits in ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on trees and grasses, leaving the knowledge gap for the stoichiometric patterns of shrubs. In this study, we explored the intra- and interspecific variations of leaf N and P concentration in relation to climate, soil property and evolutionary history based on 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China expanding 46.1° (86.7–132.8° E in longitude and 19.8° (32.6–52.4° N in latitude. The results showed that leaf N concentration decreased with precipitation, leaf P concentration decreased with temperature and increased with precipitation and soil P concentration. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentration was less conserved than leaf N concentration. At community level, climates explained more interspecific, while soil nutrient explained more intraspecific, variation of leaf nutrient concentrations. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits.

  9. Variations of leaf N, P concentrations in shrubland biomes across northern China: phylogeny, climate and soil

    Science.gov (United States)

    Yang, X.; Chi, X.; Ji, C.; Liu, H.; Ma, W.; Mohhammat, A.; Shi, Z.; Wang, X.; Yu, S.; Yue, M.; Tang, Z.

    2015-11-01

    Concentrations of leaf nitrogen (N) and phosphorus (P) are key leaf traits in ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on trees and grasses, leaving the knowledge gap for the stoichiometric patterns of shrubs. In this study, we explored the intra- and interspecific variations of leaf N and P concentration in relation to climate, soil property and evolutionary history based on 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China expanding 46.1° (86.7-132.8° E) in longitude and 19.8° (32.6-52.4° N) in latitude. The results showed that leaf N concentration decreased with precipitation, leaf P concentration decreased with temperature and increased with precipitation and soil P concentration. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentration was less conserved than leaf N concentration. At community level, climates explained more interspecific, while soil nutrient explained more intraspecific, variation of leaf nutrient concentrations. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits.

  10. Antibacterial, Antibiofilm Effect of Burdock (Arctium lappa L.) Leaf Fraction and Its Efficiency in Meat Preservation.

    Science.gov (United States)

    Lou, Zaixiang; Li, Cheng; Kou, Xingran; Yu, Fuhao; Wang, Hongxin; Smith, Gary M; Zhu, Song

    2016-08-01

    First, the antibacterial, antibiofilm effect and chemical composition of burdock (Arctium lappa L.) leaf fractions were studied. Then, the efficiency of burdock leaf fractions in pork preservation was evaluated. The results showed that burdock leaf fraction significantly inhibited the growth and biofilm development of Escherichia coli and Salmonella Typhimurium. MICs of burdock leaf fractions on E. coli and Salmonella Typhimurium were both 2 mg/ml. At a concentration of 2.0 mg/ml, the inhibition rates of the fraction on growth and development of E. coli and Salmonella Typhimurium biofilms were 78.7 and 69.9%, respectively. During storage, the log CFU per gram of meat samples treated with burdock leaf fractions decreased 2.15, compared with the samples without treatment. The shelf life of pork treated with burdock leaf fractions was extended 6 days compared with the pork without treatment, and the sensory property was obviously improved. Compared with the control group, burdock leaf fraction treatment significantly decreased the total volatile basic nitrogen value and pH of the meat samples. Chemical composition analysis showed that the burdock leaf fraction consisted of chlorogenic acid, caffeic acid, p-coumaric acid, rutin, cynarin, crocin, luteolin, arctiin, and quercetin. As a vegetable with an abundant source, burdock leaf is safe, affordable, and efficient in meat preservation, indicating that burdock leaf fraction is a promising natural preservative for pork.

  11. Evaporative properties and pinning strength of laser-ablated, hydrophilic sites on lotus-leaf-like, nanostructured surfaces.

    Science.gov (United States)

    McLauchlin, Melissa L; Yang, Dongqing; Aella, P; Garcia, Antonio A; Picraux, S T; Hayes, Mark A

    2007-04-24

    Wetting, evaporative, and pinning strength properties of hydrophilic sites on superhydrophobic, nanostructured surfaces were examined. Understanding these properties is important for surface characterization and designing features in self-cleaning, lotus-leaf-like surfaces. Laser-ablated, hydrophilic spots between 250 mum and 2 mm in diameter were prepared on silicon nanowire (NW) superhydrophobic surfaces. For larger circumference pinning sites, initial contact angle measurements resemble the contact angle of the surface within the pinning site: 65-69 degrees . As the drop volume is increased, the contact angles approach the contact angle of the NW surface without pinning sites: 171-176 degrees . The behavior of water droplets on the pinning sites is governed by how much of the water droplet is being influenced by the superhydrophobic NW surfaces versus the hydrophilic areas. During the evaporation of sinapic acid solution, drops are pinned by the spots except for the smaller circumference sites. Pinning strengths of the hydrophilic sites are a linear function of the pinning spot circumference. Protein samples prepared and deposited on the pinning sites for analysis by matrix-assisted laser desorption ionization indicate an improvement in sensitivity from that of a standard plate analysis by a factor of 5.

  12. CONCRETE PROPERTIES IMPROVEMENT OF SLAB TRACKS USING CHEMICAL ADDITIVES

    Directory of Open Access Journals (Sweden)

    V. V. Pristinskaya

    2015-11-01

    Full Text Available Purpose. On the Railways of Ukraine a very large number of slab tracks are operated with cracks. Many scientific works of previous years are dedicated to improving the design of slab tracks. The main causes of defects are: poor exploitation of the track; insufficient physic-mechanical characteristics of concrete; poor quality of initial materials. It is therefore necessary to develop an optimum concrete mix for the manufacture of these concrete products. Methodology. To assess the impact of individual factors and effects of their interactions on properties of concrete mix and concrete method of experimental and statistical modeling was used. At this, methodological fundamentals of mathematical experiment planning in concrete technology and modern methods of optimization of composite materials were taking into account. Based on the obtained data during the planned experiment conducting, including15 studies and using the computer program MathCad, were obtained the regression equations, which describe the relevant physical and mechanical properties of concrete. On the basis of the equations with the help of computer program MATLAB R2012b the graphs were drawn, illustrating the dependences of system response from the changes of two factors at a fixed value of the third factor. Findings. Firstly was the analysis of cracks that occur in the process of operation in the constructions of slab tracks. Further reasons of possible occurrence of these cracks were presented. In the process of the conducted research the author has concluded that for rational concrete mix development it is necessary to conduct the planned experiment with the use of quality materials. It was established that to increase the strength, chemical additives should be added in to concrete mix, it will let reduce cement amount. Originality. Experiments proved the usage of modern chemical additives in order to improve the properties of concrete. Models were developed, reflecting

  13. Field emission properties of chemical vapor deposited individual graphene

    Energy Technology Data Exchange (ETDEWEB)

    Zamri Yusop, Mohd [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Department of Materials, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Center for Fostering Young and Innovative Researchers, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan); Yaakob, Yazid; Takahashi, Chisato; Tanemura, Masaki [Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, 466-8555 Nagoya (Japan)

    2014-03-03

    Here, we report field emission (FE) properties of a chemical vapor deposited individual graphene investigated by in-situ transmission electron microscopy. Free-standing bilayer graphene is mounted on a cathode microprobe and FE processes are investigated varying the vacuum gap of cathode and anode. The threshold field for 10 nA current were found to be 515, 610, and 870 V/μm for vacuum gap of 400, 300, and 200 nm, respectively. It is observed that the structural stability of a high quality bilayer graphene is considerably stable during emission process. By contacting the nanoprobe with graphene and applying a bias voltage, structural deformation and buckling are observed with significant rise in temperature owing to Joule heating effect. The finding can be significant for practical application of graphene related materials in emitter based devices as well as understanding the contact resistance influence and heating effect.

  14. Influence of Biomass Chemical Properties on Torrefaction Characteristics

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt

    2013-01-01

    Different biomass types may differ with respect to torrefaction characteristics, and an improved understanding and ability to predict the torrefaction performance is, therefore, desired. In this study, the influence of the chemical properties (lignocellulose composition and alkali content......) on the torrefaction behavior with respect to mass loss and grindability is investigated by simultaneous thermal analysis (STA) and by using a combined torrefaction and grinding reactor. The torrefaction behavior of six raw biomass samples and selected pretreated samples (washed and impregnated with KCl and K2CO3) has...... of the torrefied products was evaluated by determining the d50 value of the particle size distribution of the biomass before and after torrefaction in the combined torrefaction and mill reactor. A significant decrease in d50 value was observed when the alkali content increased from 0 to 0.2 wt % db, whereas...

  15. Irradiation effects on color and functional properties of persimmon (Diospyros kaki L. folium) leaf extract and licorice (Glycyrrhiza Uralensis Fischer) root extract during storage

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Cheorun; Son, J.H.; Shin, M.G.; Byun, M.W. E-mail: mwbyun@kaeri.re.kr

    2003-06-01

    Irradiation effects on color and functional properties of persimmon (Diospyros kaki L. folium) leaf extract and licorice (Glycyrrhiza Uralensis Fischer) root extract were studied. Persimmon leaf and licorice root extracts were irradiated using {sup 60}Co gamma irradiator at 0 and 20 kGy absorbed dose and stored at 4 deg. C or -20 deg. C for 2 weeks. Tyrosinase inhibition effect (TIE) of both extracts was not different by 20 kGy-irradiation but reduced during storage. Electron donating ability (EDA) of the persimmon leaf extract was generally consistent, but that of licorice root extract was reduced by irradiation except for 1 week of storage. Both TIE and EDA of persimmon leaf extract were higher than that of licorice root. Hunter color L*-, a*-, and b*-values were changed, resulting in a desirable brighter color by irradiation. During storage, the bright yellow color of irradiated sample changed to brown gradually, and especially the changes in the refrigeration condition (4 deg. C) was faster than frozen (-20 deg. C). Results indicate that irradiation can be a useful method to produce value-added natural ingredients with functions such as persimmon leaf or licorice root for food or cosmetic industry in addition to elimination of microbial load.

  16. Chemical and physical properties of dry flue gas desulfurization products.

    Science.gov (United States)

    Kost, David A; Bigham, Jerry M; Stehouwer, Richard C; Beeghly, Joel H; Fowler, Randy; Traina, Samuel J; Wolfe, William E; Dick, Warren A

    2005-01-01

    Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong preferential partitioning into the acid insoluble residue (i.e., coal ash residue) was observed for Al, Ba, Be, Cr, Fe, Li, K, Pb, Si, and V. Sulfur, Ca, and Mg occurred primarily in water- or acid-soluble forms associated with the sorbents or scrubber reaction products. Deionized water leachates (American Society for Testing and Materials [ASTM] method) and dilute acetic acid leachates (toxicity characteristic leaching procedure [TCLP] method) had mean pH values of >11.2 and high mean concentrations of S primarily as SO(2-)4 and Ca. Concentrations of Ag, As, Ba, Cd, Cr, Hg, Pb, and Se (except for ASTM Se in two samples) were below drinking water standards in both ASTM and TCLP leachates. Total toxicity equivalents (TEQ) of dioxins, for two FGD products used for mine reclamation, were 0.48 and 0.53 ng kg(-1). This was similar to the background level of the mine spoil (0.57 ng kg(-1)). The FGD materials were mostly uniform in particle size. Specific surface area (m2 g(-1)) was related to particle size and varied from 1.3 for bed ash to 9.5 for spray dryer material. Many of the chemical and physical properties of these FGD samples were associated with the quality of the coal rather than the combustion and SO2 scrubbing processes used.

  17. Chemical and Thermodynamic Properties at High Temperatures: A Symposium

    Science.gov (United States)

    Walker, Raymond F.

    1961-01-01

    This book contains the program and all available abstracts of the 90' invited and contributed papers to be presented at the TUPAC Symposium on Chemical and Thermodynamic Properties at High Temperatures. The Symposium will be held in conjunction with the XVIIIth IUPAC Congress, Montreal, August 6 - 12, 1961. It has been organized, by the Subcommissions on Condensed States and on Gaseous States of the Commission on High Temperatures and Refractories and by the Subcommission on Experimental Thermodynamics of the Commission on Chemical Thermodynamics, acting in conjunction with the Organizing Committee of the IUPAC Congress. All inquiries concerning participation In the Symposium should be directed to: Secretary, XVIIIth International Congress of Pure and Applied Chemistry, National Research Council, Ottawa, 'Canada. Owing to the limited time and facilities available for the preparation and printing of the book, it has not been possible to refer the proofs of the abstracts to the authors for checking. Furthermore, it has not been possible to subject the manuscripts to a very thorough editorial examination. Some obvious errors in the manuscripts have been corrected; other errors undoubtedly have been introduced. Figures have been redrawn only when such a step was essential for reproduction purposes. Sincere apologies are offered to authors and readers for any errors which remain; however, in the circumstances neither the IUPAC Commissions who organized the Symposium, nor the U. S. Government Agencies who assisted in the preparation of this book can accept responsibility for the errors.

  18. Chemical composition and larvicidal activity of Elaeagnus indica Servett. (Elaeagnaceae plant leaf extracts against dengue and malaria vectors

    Directory of Open Access Journals (Sweden)

    Ramalingam Srinivasan

    2014-12-01

    Full Text Available MMosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The acetone, chloroform, ethyl acetate, hexane, methanol and petroleum benzene leaf extracts of E. indica were tested against fourth instar larvae of malaria vector, Anopheles stephensi and dengue vector, Aedes aegypti. The larval mortality was observed after 24 h of exposure. Highest larval mortality was found in acetone leaf extracts against A. aegypti (LC50 and LC90 values of 2.97027and 5.9820 mg/ml and A. stephensi (LC50 and LC90 values of 3.92501 and 68.3250 mg/ml respectively. GC-MS analysis of plant extracts of acetone solvent revealed 19 compounds, of which the major compounds were -Thujone 1-Isopropyl-4-Methylbicyclo(3.1.0Hexan-3-One 1- (6.71%, 1,6- Cyclodecadiene, 1-Methyl-5-Methylene-8-(1-Methylethyl-, [S-(E,E]-Germacra-1(10,4(15,5-Trie N (3.11%, L-(+-Ascorbic Acid 2,6-Dihexadecanoate (4.06%, 2-Cyclohexylcyclohexanol [1,1'-Bicyclohexyl]-2-Ol (3.16%, Dotriacontane N- Bicetyl (58.7% and Tetrapentacontane (3.85%. E. indica offers promise as potential biocontrol agent against major dengue and malaria mosquitoes particularly in larvicidal effect. Our results shows acetone leaf extracts of E. indica have the potential to be used as an ideal eco-friendly approach for control of mosquito vectors.

  19. Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein

    Science.gov (United States)

    Alfalfa, traditionally used for animal feed, has attracted attention as a potential feedstock for biofuels and the viability of the process would be enhanced by co-products with value-added uses. This study describes extraction of protein from dried alfalfa leaves and the functional properties of th...

  20. Chemical Properties of Dipole-Bound Negative Ions

    Science.gov (United States)

    Liu, Y.

    2005-05-01

    In dipole bound negative ions the extra electron is weakly bound by the dipole potential of the neutral molecule in a diffuse orbital localized near the positive end of the dipole. In consequence, it is reasonable to expect that such species will be highly reactive and possess chemical properties similar to those of Rydberg atoms, which also contain a weakly-bound electron in a diffuse orbital. These properties are being examined using a negative ion Penning trap. Data for electron transfer in collisions with attaching targets such as SF6 show that the rate constants for this process are large, ˜ 10-7 cm^3 s-1, and similar to those for free electron attachment. This suggests that collisions can be described in terms of an essentially-free electron model. This is further reinforced by the observation that rotational energy transfer in collisions with polar molecules can lead to rapid electron detachment, again with large rate constants of ˜ 10 -7 cm^3 s-1. Results for several target species will be presented and discussed in light of a free electron model.

  1. Robinia pseudoacacia leaves improve soil physical and chemical properties

    Institute of Scientific and Technical Information of China (English)

    Babar; KHAN; Abdukadir; Ablimit; Rashed; MAHMOOD; Muhammad; QASIM

    2010-01-01

    The role of the leaves of Robinia pseudoacacia L., which is widely distributed in the arid lands, on improving soil physical and chemical properties was analyzed at various incubation periods. The incubated soils added with 0, 25, 50 and 75 g Robinia pseudoacacia leaves were tested after consecutive incubation intervals of 6, 8 and 10 months and the different soil parameters were measured. The results showed the increases in organic matter (OM), extractable K, cation exchange capacity (CEC), aggregate stability and water holding capacity, but the decreases in pH value and bulk density after 6 months’ incubation. The gradual decrease in change rates of soil properties indicated less microbial population and organic residual mineralization under acidic conditions, which were resulted from fast decomposition of leaves after the first 6 months incubation. The increases in soil organic matter content, extractable K, CEC, aggregate stability and water holding capacity and the decreases in soil pH and bulk density provide favorable conditions for crop’s growth.

  2. Robinia pseudoacacia leaves improve soil physical and chemical properties

    Institute of Scientific and Technical Information of China (English)

    Babar KHAN; Abdukadir Ablimit; Rashed MAHMOOD; Muhammad QASIM

    2010-01-01

    The role of the leaves of Robinia pseudoacacia L.,which is widely distributed in the arid lands,on improving soil physical and chemical properties was analyzed at various incubation periods.The incubated soils added with 0,25,50 and 75 g Robinia pseudoacacia leaves were tested after consecutive incubation intervals of 6,8 and 10 months and the different soil parameters were measured.The results showed the increases in organic matter (OM),extractable K,cation exchange capacity (CEC),aggregate stability and water holding capacity,but the decreases in pH value and bulk density after 6 months' incubation.The gradual decrease in change rates of soil properties indicated less microbial population and organic residual mineralization under acidic conditions,which were resulted from fast decomposition of leaves after the first 6 months incubation.The increases in soil organic matter content,extractable K,CEC,aggregate stability and water holding capacity and the decreases in soil pH and bulk density provide favorable conditions for crop's growth.

  3. Chemical composition and antibacterial activity of the essential oils from flower, leaf and stem of Ferula cupularis growing wild in Iran.

    Science.gov (United States)

    Alipour, Ziba; Taheri, Poroshat; Samadi, Nasrin

    2015-04-01

    Ferula cupularis (Boiss.) Spalik et S. R. Downie (Apiaceae) is a common plant in Iran that grows in the foothills of Dena Mountain. In traditional folk medicine, this plant has different applications, but there are no studies proving their uses. This study is the first attempt to investigate the chemical composition and antibacterial effect of the essential oils of F. cupularis. The essential oils from flower, leaf, and stem of F. cupularis were analyzed by using GC and GC-MS. Antibacterial activity of essential oils was determined by microdilution method against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The essential oil from flower of F. cupularis contained 15 monoterpene, 13 oxygenated monoterpene, and 2 sesquiterpene hydrocarbons. The leaf essential oil contained 12 monoterpene, 13 oxygenated monoterpene, 2 sesquiterpene, 6 oxygenated sesquiterpene hydrocarbons, and 3 non-terpenoid components. Stem essential oil contained one monoterpene, 23 oxygenated monoterpene, 2 sesquiterpene, and 6 oxygenated sesquiterpene hydrocarbons. The MIC value of stem essential oil was 2.85 mg/mL against both Gram-positive bacteria and Gram-negative bacteria except P. aeruginosa which was inhibited at 22.75 mg/mL. The MIC values of leaf and flower essential oils were higher than 5.69 and 22.75 mg/mL, respectively. This study highlighted the strong antibacterial effect of Ferula cupularis's essential oil which might be due to its high content of oxygenated monoterpene hydrocarbons. Our results suggested that this plant may be a good candidate for further biological and pharmacological investigations.

  4. Chemical control of the properties of perovskite oxides

    Science.gov (United States)

    Tachibana, Makoto

    2010-03-01

    Perovskite oxides show a variety of interesting properties that can be tuned by chemical control. In this talk, I will present three examples of how such approach can be used to study the nature of functional properties in perovskites: (1) RMnO3 (R=rare earth) show a variety of unusual states, including the spiral spin ordering and ferroelectricity in R=Tb and Dy. In [1], R=Ho-Lu have been obtained under high pressure, and their magnetic and structural properties have been studied. Combined with the data on larger R, the results show the importance of competing magnetic interactions on the complex phase diagram of RMnO3. (2) RCoO3 show a spin-state transition and an insulator-metal transition as a function of temperature. The nature of the excited states has been studied since the 1950's, but remains elusive. Here [2], I provide the complete electronic phase diagram of RCoO3 that has been obtained from high-pressure synthesis and heat capacity measurements. The results support a picture involving a high-spin state above the spin-state transition and an intermediate-spin state above the insulator-metal transition. (3) Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) is a relaxor ferroelectric system with extraordinary dielectric and piezoelectric properties. The average structure of the system changes from cubic to rhombohedral, monoclinic, and tetragonal with x. However, this system is also characterized by nanoscale phase inhomogeneities, and the role of polar nanoregions on the enhanced properties is not clear. Here [3], I will show that thermal conductivity and heat capacity of PMN-xPT show a systematic evolution from glasslike to crystalline behavior as a function of x. The results provide interesting perspectives on how polar nanoregions are transformed into macroscopic polarizations with increasing x. [4pt] [1] M. Tachibana et al., Phys. Rev. B 75, 144425 (2007). [0pt] [2] M. Tachibana et al., Phys. Rev. B 77, 094402 (2008). [0pt] [3] M. Tachibana et al., Phys. Rev. B 79

  5. Structure-function characterization of the crinkle-leaf peach wood phenotype: a future model system for wood properties research?

    Science.gov (United States)

    Variations in wood features of two genotypes of Prunus persica L. trees, wild-type and crinkle-leaf, were examined to elucidate the nature of weak wood in crinkle-leaf trees. Trees from three vigor classes (low, average, and high) of each genotype were sampled. No meaningful tendency of dissimilarit...

  6. Variations of leaf N and P concentrations in shrubland biomes across northern China: phylogeny, climate, and soil

    Science.gov (United States)

    Yang, Xian; Chi, Xiulian; Ji, Chengjun; Liu, Hongyan; Ma, Wenhong; Mohhammat, Anwar; Shi, Zhaoyong; Wang, Xiangping; Yu, Shunli; Yue, Ming; Tang, Zhiyao

    2016-08-01

    Concentrations of leaf nitrogen (N) and phosphorus (P) are two key traits of plants for ecosystem functioning and dynamics. Foliar stoichiometry varies remarkably among life forms. However, previous studies have focused on the stoichiometric patterns of trees and grasses, leaving a significant knowledge gap for shrubs. In this study, we explored the intraspecific and interspecific variations of leaf N and P concentrations in response to the changes in climate, soil property, and evolutionary history. We analysed 1486 samples composed of 163 shrub species from 361 shrubland sites in northern China encompassing 46.1° (86.7-132.8° E) in longitude and 19.8° (32.6-52.4° N) in latitude. Leaf N concentrations decreased with precipitation, while leaf P concentrations decreased with temperature and increased with precipitation and soil total P concentrations. Both leaf N and P concentrations were phylogenetically conserved, but leaf P concentrations were less conserved than leaf N concentrations. At the community level, climate explained more interspecific variation of leaf nutrient concentrations, while soil nutrients explained most of the intraspecific variation. These results suggested that leaf N and P concentrations responded to climate, soil, and phylogeny in different ways. Climate influenced the community chemical traits through the shift in species composition, whereas soil directly influenced the community chemical traits. New patterns were discovered using our observations on specific regions and vegetation types, which improved our knowledge of broad biogeographic patterns of leaf chemical traits.

  7. The impact of chemical evolution on the observable properties of stellar populations

    CERN Document Server

    Tosi, M P

    2000-01-01

    The major effects of the chemical evolution of galaxies on the characteristics of their stellar populations are reviewed. A few examples of how the observed stellar properties derived from colour--magnitude diagrams can constrain chemical evolution models are given.

  8. Mechanical properties of uniaxial natural fabric Grewia tilifolia reinforced epoxy based composites: Effects of chemical treatment

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2014-07-01

    Full Text Available The effects of chemical treatment on the mechanical, morphological, and chemical resistance properties of uniaxial natural fabrics, Grewia tilifolia/epoxy composites, were studied. In order to enhance the interfacial bonding between the epoxy matrix...

  9. Quantitative structure-property relationships for chemical functional use and weight fractions in consumer articles

    Science.gov (United States)

    Chemical functional use -- the functional role a chemical plays in processes or products -- may be a useful heuristic for predicting human exposure potential in that it comprises information about the compound's likely physical properties and the product formulations or articles ...

  10. Antioxidant properties of Taraxacum officinale leaf extract are involved in the protective effect against hepatoxicity induced by acetaminophen in mice.

    Science.gov (United States)

    Colle, Dirleise; Arantes, Leticia Priscilla; Gubert, Priscila; da Luz, Sônia Cristina Almeida; Athayde, Margareth Linde; Teixeira Rocha, João Batista; Soares, Félix Alexandre Antunes

    2012-06-01

    Acetaminophen (APAP) hepatotoxicity has been related to several cases of hepatitis, cirrhosis, and hepatic transplant. As APAP hepatotoxicity is related to reactive oxygen species (ROS) formation and excessive oxidative stress, natural antioxidant compounds have been tested as an alternative therapy to diminish the hepatic dysfunction induced by APAP. Taraxacum officinale Weber (Family Asteraceae), commonly known as dandelion, is used for medicinal purposes because of its choleretic, diuretic, antioxidant, anti-inflammatory, and hepatoprotective properties. This study evaluated the hepatoprotective activity of T. officinale leaf extract against APAP-induced hepatotoxicity. T. officinale was able to decrease thiobarbituric acid-reactive substance levels induced by 200 mg/kg APAP (p.o.), as well as prevent the decrease in sulfhydryl levels caused by APAP treatment. Furthermore, histopathological alterations, as well as the increased levels of serum aspartate and alanine aminotransferases caused by APAP, were prevented by T. officinale (0.1 and 0.5 mg/mL). In addition, T. officinale extract also demonstrated antioxidant activity in vitro, as well as scavenger activity against 2,2-diphenyl-1-picrylhydrazyl and nitric oxide radicals. Our results clearly demonstrate the hepatoprotective effect of T. officinale against the toxicity induced by APAP. The possible mechanisms involved include its scavenger activities against ROS and reactive nitrogen species, which are attributed to the content of phenolic compounds in the extract.

  11. Effect of Vaccinium bracteatum Thunb. leaf pigment on the thermal, pasting, and textural properties and microstructure characterization of rice starch.

    Science.gov (United States)

    Xu, Yuan; Fan, Mingcong; Zhou, Sumei; Wang, Li; Qian, Haifeng; Zhang, Hui; Qi, Xiguang

    2017-08-01

    In this study, the thermal, pasting and gel textural properties of japonica rice starch (JRS) and glutinous rice starch (GRS) fortified with Vaccinium bracteatum Thunb. leaf pigment (VBTLP) were investigated. The results showed that VBTLP facilitated the gelatinization of JRS and GRS with earlier onsets of onset temperature (To), peak temperature (Tp), conclusion temperature (Tc), and lower values of gelatinization enthalpy (ΔHg), and retrogradation enthalpy (ΔHr), as the VBTLP level increased. For JRS, VBTLP increased the peak viscosity and breakdown, reduced the final viscosity and setback, but for GRS it increased the peak viscosity, final viscosity, breakdown and setback. VBTLP also reduced the hardness and adhesiveness of the JRS gel. The values of lightness (L(∗)) for JRS and GRS with VBTLP decreased by 47.60 and 49.56%, respectively. Scanning electron microscopy (SEM) revealed that VBTLP caused looser matrices in dried JRS and GRS gels which had lower crystallinities compared with the control. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Chemical and nuclear properties of Rutherfordium (Element 104)

    Energy Technology Data Exchange (ETDEWEB)

    Kacher, C.D.

    1995-10-30

    The chemical-properties of rutherfordium (Rf) and its group 4 homologs were studied by sorption on glass support surfaces coated with cobalt(II)ferrocyanide and by solvent extraction with tributylphosphate (TBP) and triisooctylamine (TIOA). The surface studies showed that the hydrolysis trend in the group 4 elements and the pseudogroup 4 element, lb, decreases in the order Rf>Zr{approx}Hf>Th. This trend was attributed to relativistic effects which predicted that Rf would be more prone to having a coordination number of 6 than 8 in most aqueous solutions due to a destabilization of the 6d{sub 5/2} shell and a stabilization of the 7p{sub l/2} shell. This hydrolysis trend was confirmed in the TBP/HBr solvent extraction studies which showed that the extraction trend decreased in the order Zr>Hf>Rf?Ti for HBr, showing that Rf and Ti did not extract as well because they hydrolyzed more easily than Zr and Hf. The TIOA/HF solvent extraction studies showed that the extraction trend for the group 4 elements decreased in the order Ti>Zr{approx}Hf>Rf, in inverse order from the trend of ionic radii Rf>Zr{approx}Hf>Ti. An attempt was made to produce {sup 263}Rf (a) via the {sup 248}Cm({sup 22}Ne, {alpha}3n) reaction employing thenoyltrifluoroacetone (TTA) solvent extraction chemistry and (b) via the {sup 249}Bk({sup 18}O,4n) reaction employing the Automated Rapid Chemistry Apparatus (ARCA). In the TTA studies, 16 fissions were observed but were all attributed to {sup 256}Fm. No alpha events were observed in the Rf chemical fraction. A 0.2 nb upper limit production cross section for the {sup 248}Cm({sup 22}Ne, {alpha}3n){sup 263}Rf reaction was calculated assuming the 500-sec half-life reported previously by Czerwinski et al. [CZE92A].

  13. Comparison of Reflectance Measurements Acquired with a Contact Probe and an Integration Sphere: Implications for the Spectral Properties of Vegetation at a Leaf Level

    Directory of Open Access Journals (Sweden)

    Markéta Potůčková

    2016-10-01

    Full Text Available Laboratory spectroscopy in visible and infrared regions is an important tool for studies dealing with plant ecophysiology and early recognition of plant stress due to changing environmental conditions. Leaf optical properties are typically acquired with a spectroradiometer coupled with an integration sphere (IS in a laboratory or with a contact probe (CP, which has the advantage of operating flexibility and the provision of repetitive in-situ reflectance measurements. Experiments comparing reflectance spectra measured with different devices and device settings are rarely reported in literature. Thus, in our study we focused on a comparison of spectra collected with two ISs on identical samples ranging from a Spectralon and coloured papers as reference standards to vegetation samples with broadleaved (Nicotiana Rustica L. and coniferous (Picea abies L. Karst. leaf types. First, statistical measures such as mean absolute difference, median of differences, standard deviation and paired-sample t-test were applied in order to evaluate differences between collected reflectance values. The possibility of linear transformation between spectra was also tested. Moreover, correlation between normalised differential indexes (NDI derived for each device and all combinations of wavelengths between 450 nm and 1800 nm were assessed. Finally, relationships between laboratory measured leaf compounds (total chlorophyll, carotenoids and water content, NDI and selected spectral indices often used in remote sensing were studied. The results showed differences between spectra acquired with different devices. While differences were negligible in the case of the Spectralon and they were possible to be modelled with a linear transformation in the case of coloured papers, the spectra collected with the CP and the ISs differed significantly in the case of vegetation samples. Regarding the spectral indices calculated from the reflectance data collected with the three

  14. Physical, Chemical and Mineral Properties of the Polonnaruwa Stones

    Science.gov (United States)

    Wallis, Jamie; Wickramasinghe, N. C.; Wallis, Daryl H.; Miyake, Nori; Wallis, M. K.; Hoover, Richard B.; Samaranayake, Anil; Wickramarathne, Keerthi; Oldroyd, Anthony

    We report on the physical, chemical and mineral properties of a series of stone fragments recovered from the North Central Province of Sri Lanka following a witnessed fireball event on 29 December 2012. The stones exhibit highly porous poikilitic textures comprising of isotropic silica-rich/plagioclase-like hosts. Inclusions range in size and shape from mm-sized to smaller subangular grains frequently more fractured than the surrounding host and include ilmenite, olivine (fayalitic), quartz and accessory zircon. Bulk mineral compositions include accessory cristobalite, hercynite, anorthite, wuestite, albite, anorthoclase and the high pressure olivine polymorph wadsleyite, suggesting previous endurance of a shock pressure of ~20GPa. Further evidence of shock is confirmed by theconversion of all plagioclase to maskelynite. Here the infrared absorption spectra in the region 580 cm-1 to 380 cm-1 due to the Si-O-Si or Si-O-Al absorption band shows a partial shift in the peak at 380 cm-1 towards 480 cm-1 indicating an intermediate position between crystalline and amorphous phase. Host matrix chemical compositions vary between samples, but all are rich in SiO2. Silica-rich melts display a heterogeneous K-enrichment comparable to that reported in a range of nonterrestrial material from rare iron meteorites to LL chondritic breccias and Lunar granites. Bulk chemical compositions of plagioclase-like samples are comparable to reported data e.g. Miller Ranger 05035 (Lunar), while Si-rich samples accord well with mafic and felsic glasses reported in NWA 1664 (Howardite)as well asdata for fusion crust present in a variety of meteoritic samples.Triple oxygen isotope results show Δ17O = .0.335 with δ18O (‰ rel. SMOW) values of 17.816 ± 0.100 and compare well with those of known CI chondrites and are within the range of CI-like (Meta-C) chondrites. Rare earth elemental abundances show a profound Europium anomaly of between 0.7 and 0.9 ppm while CI normalized REE patterns

  15. Effects of artichoke (Cynara scolymus) leaf and bloom head extracts on chemically induced DNA lesions in Drosophila melanogaster

    Science.gov (United States)

    Jacociunas, Laura Vicedo; Dihl, Rafael Rodrigues; Lehmann, Mauricio; de Barros Falcão Ferraz, Alexandre; Richter, Marc François; da Silva, Juliana; de Andrade, Heloísa Helena Rodrigues

    2014-01-01

    The genotoxicity of bloom head (BHE) and leaf (LE) extracts from artichoke (Cynara scolymus L.), and their ability to modulate the mutagenicity and recombinogenicity of two alkylating agents (ethyl methanesulfonate – EMS and mitomycin C – MMC) and the intercalating agent bleomycin (BLM), were examined using the somatic mutation and recombination test (SMART) in Drosophila melanogaster. Neither the mutagenicity nor the recombinogenicity of BLM or MMC was modified by co- or post-treatment with BHE or LE. In contrast, co-treatment with BHE significantly enhanced the EMS-induced genotoxicity involving mutagenic and/or recombinant events. Co-treatment with LE did not alter the genotoxicity of EMS whereas post-treatment with the highest dose of LE significantly increased this genotoxicity. This enhancement included a synergistic increase restricted to somatic recombination. These results show that artichoke extracts promote homologous recombination in proliferative cells of D. melanogaster. PMID:24688296

  16. Antioxidant activity and chemical components as potential anticancer agents in the olive leaf (Olea europaea L. cv Leccino.) decoction.

    Science.gov (United States)

    De Marino, Simona; Festa, Carmen; Zollo, Franco; Nini, Antonella; Antenucci, Lina; Raimo, Gennaro; Iorizzi, Maria

    2014-01-01

    Epidemiological studies have shown that a reduced risk of chronic diseases such as cancer and cardiovascular diseases is correlated with a regular consumption of fruits and vegetable, many of which are rich in polyphenols. The additive and synergistic effect of phytochemicals in fruits and vegetables may reduce chronic diseases related to oxidative stress in human body. Olea europaea L. leaf are rich in phenolic components, which have been proposed to play a role in cancer prevention. The purpose of this study was to identify the main components in the Olea europaea L. leaf (cv. Leccino) preserved during the decoction preparation, in order to delineate the antioxidant activities of the crude extracts and its isolated compounds by using different in vitro assays including DPPH radicalscavenging capacity, total antioxidant capacity (TAC), xanthine oxidase (XO) inhibitory effect and the ability to delay the linoleic acid peroxidation process (ALP). The aqueous decoction was partitioned obtaining four extracts and the n-butanol extract showed the highest antioxidant activity and the highest total phenolic content. Phytochemical investigation leads to the isolation of thirteen secondary metabolites including simple phenolics, flavonoids, secoiridoids whose structures were elucidated by spectroscopic data (1D and 2D NMR) and spectrometric techniques. A significant free radical scavenging effect against DPPH has been evidenced in fraxamoside (1) (EC50 62.6 µM) and taxifolin (5) (EC50 50.0 µM), isolated for the first time from the water decoction. The most active compound in the TAC evaluation, was the 3,4 dihydro-phenyl glycol (8) (0.90 caffeic acid equiv.) while taxifolin and fraxamoside resulted as the most efficient inhibitors of XO activity (IC50 2.7 and 5.2 µM, respectively). Secoxyloganin (4), oleuropein (2) and tyrosol (6) showed the highest ALP activity. This study adds to the growing body of data supporting the bioactivities of phytochemicals and their

  17. Hygroscopic, Morphological, and Chemical Properties of Agricultural Aerosols

    Science.gov (United States)

    Hiranuma, N.; Brooks, S. D.; Cheek, L.; Thornton, D. C.; Auvermann, B. W.; Littleton, R.

    2007-12-01

    Agricultural fugitive dust is a significant source of localized air pollution in the semi-arid southern Great Plains. In the Texas Panhandle, daily episodes of ground-level fugitive dust emissions from the cattle feedlots are routinely observed in conjunction with increased cattle activity in the late afternoons and early evenings. We conducted a field study to characterize size-selected agricultural aerosols with respect to hygroscopic, morphological, and chemical properties and to attempt to identify any correlations between these properties. To explore the hygroscopic nature of agricultural particles, we have collected size-resolved aerosol samples using a cascade impactor system at a cattle feedlot in the Texas Panhandle and have used the Environmental Scanning Electron Microscope (ESEM) to determine the water uptake by individual particles in those samples as a function of relative humidity. To characterize the size distribution of agricultural aerosols as a function of time, A GRIMM aerosol spectrometer and Sequential Mobility Particle Sizer and Counter (SMPS) measurements were simultaneously performed in an overall size range of 11 nm to 20 µm diameters at a cattle feedlot. Complementary determination of the elemental composition of individual particles was performed using Energy Dispersive X-ray Spectroscopy (EDS). In addition to the EDS analysis, an ammonia scrubber was used to collect ammonia and ammonium in the gas and particulate phases, respectively. The concentration of these species was quantified offline via UV spectrophotometry at 640 nanometers. The results of this study will provide important particulate emission data from a feedyard, needed to improve our understanding of the role of agricultural particulates in local and regional air quality.

  18. 蓖麻叶挥发油化学成分分析%Analysis of chemical compositions of the essential oil in the leaf of Ricinus communis

    Institute of Scientific and Technical Information of China (English)

    陈月华; 陈利军; 石庆锋

    2012-01-01

    采用水蒸汽蒸馏法从蓖麻叶中提取挥发油,利用CC—MS联用仪对蓖麻叶挥发油的化学成分进行研究,共分离到52个组分,鉴定了其中的31个,占挥发油总量的77.223%。蓖麻叶挥发油主要成分是壬醛(14.718%)、二环[3.2.0]庚-2-酮(7.773%)、2,4-癸二烯醛(6.237%)、(E)-4-(2,6,6-三甲基-1-环己烯-l-基)-3-丁烯-2-酮(6.056%)、(E)-2-癸醛(5.967%)、(E)-6,10-二甲基-5,9-十-碳二烯-2-酮(5.063%)等。%To analyze the chemical compositions of the essential oil in the leaf of Ricinus communis, the essential oil was extracted from the leaf of R. communis by steam distillation, and then an analysis was conducted by applying GC - MS. The result shows that 52 ingredients have been found, and 31 of them have been identified, accounting for 77.223% of the total essential oil. The main chemical components of the leaf of R. communis are: Nonanal( 14. 718% ) ,Bicyclo [ 3.2.0 ] heptan - 2 - one (7. 773 % ), 2,4 - Decadienal ( 6. 237 % ), 3 -Buten - 2 - one, 4 - ( 2,6,6 - trimethyl - 1 - cyclohexen - 1 - yl) - , (E) - (6. 056% ) ,2 - Decenal, (E) - (5. 967% ) ,5,9 - Undecadien - 2 - one, 6,10 - dime- thyl -, (E) - (5.063%)etc.

  19. Chemical properties and antioxidant and antimicrobial activities of Slovenian propolis.

    Science.gov (United States)

    Mavri, Ana; Abramovič, Helena; Polak, Tomaž; Bertoncelj, Jasna; Jamnik, Polona; Smole Možina, Sonja; Jeršek, Barbara

    2012-08-01

    The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts PEE70 and PEE96, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the PEE70 was richer in total phenolic compounds than the PEE96. The Slovenian propolis was characterized by different phenolic acids and flavonoids. The PEE96 was slightly richer in three specific compounds, i.e., caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the PEE70. The PEE70 showed a stronger reducing power and ability to scavenge free radicals and metal ions than the PEE96. Both PEEs were in the main more effective against Gram-positive bacteria than against fungi and Gram-negative bacteria like Salmonella and Escherichia coli, with the exception of Campylobacter. The PEE96 decreased the intracellular oxidation in Saccharomyces cerevisiae in a dose-dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods.

  20. Plant polyphenols: chemical properties, biological activities, and synthesis.

    Science.gov (United States)

    Quideau, Stéphane; Deffieux, Denis; Douat-Casassus, Céline; Pouységu, Laurent

    2011-01-17

    Eating five servings of fruits and vegetables per day! This is what is highly recommended and heavily advertised nowadays to the general public to stay fit and healthy! Drinking green tea on a regular basis, eating chocolate from time to time, as well as savoring a couple of glasses of red wine per day have been claimed to increase life expectancy even further! Why? The answer is in fact still under scientific scrutiny, but a particular class of compounds naturally occurring in fruits and vegetables is considered to be crucial for the expression of such human health benefits: the polyphenols! What are these plant products really? What are their physicochemical properties? How do they express their biological activity? Are they really valuable for disease prevention? Can they be used to develop new pharmaceutical drugs? What recent progress has been made toward their preparation by organic synthesis? This Review gives answers from a chemical perspective, summarizes the state of the art, and highlights the most significant advances in the field of polyphenol research. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Mechanical and chemical properties of cysteine-modified kinesin molecules.

    Science.gov (United States)

    Iwatani, S; Iwane, A H; Higuchi, H; Ishii, Y; Yanagida, T

    1999-08-10

    To probe the structural changes within kinesin molecules, we made the mutants of motor domains of two-headed kinesin (4-411 aa) in which either all the five cysteines or all except Cys45 were mutated. A residual cysteine (Cys45) of the kinesin mutant was labeled with an environment-sensitive fluorescent probe, acrylodan. ATPase activity, mechanical properties, and fluorescence intensity of the mutants were measured. Upon acrylodan-labeled kinesin binding to microtubules in the presence of 1 mM AMPPNP, the peak intensity was enhanced by 3.4-fold, indicating the structural change of the kinesin head by the binding. Substitution of cysteines decreased both the maximum microtubule-activated ATPase and the sliding velocity to the same extent. However, the maximum force and the step size were not affected; the force produced by a single molecule was 6-6.5 pN, and a step size due to the hydrolysis of one ATP molecule by kinesin molecules was about 10 nm for all kinesins. This step size was close to a unitary step size of 8 nm. Thus, the mechanical events of kinesin are tightly coupled with the chemical events.

  2. Essential oils from neotropical Myrtaceae: chemical diversity and biological properties.

    Science.gov (United States)

    Stefanello, Maria Élida Alves; Pascoal, Aislan C R F; Salvador, Marcos J

    2011-01-01

    Myrtaceae family (121 genera, 3800-5800 spp.) is one of the most important families in tropical forests. They are aromatic trees or shrubs, which frequently produce edible fruits. In the neotropics, ca. 1000 species were found. Several members of this family are used in folk medicine, mainly as an antidiarrheal, antimicrobial, antioxidant, cleanser, antirheumatic, and anti-inflammatory agent and to decrease the blood cholesterol. In addition, some fruits are eaten fresh or used to make juices, liqueurs, and sweets very much appreciated by people. The flavor composition of some fruits belonging to the Myrtaceae family has been extensively studied due to their pleasant and intense aromas. Most of the essential oils of neotropical Myrtaceae analyzed so far are characterized by predominance of sesquiterpenes, some with important biological properties. In the present work, chemical and pharmacological studies carried out on neotropical Myrtaceae species are reviewed, based on original articles published since 1980. The uses in folk medicine and chemotaxonomic importance of secondary metabolites are also briefly discussed.

  3. Chemical, Mineralogical, and Physical Properties of Martian Dust and Soil

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2017-01-01

    Global and regional dust storms on Mars have been observed from Earth-based telescopes, Mars orbiters, and surface rovers and landers. Dust storms can be global and regional. Dust is material that is suspended into the atmosphere by winds and has a particle size of 1-3 micrometer. Planetary scientist refer to loose unconsolidated materials at the surface as "soil." The term ''soil'' is used here to denote any loose, unconsolidated material that can be distinguished from rocks, bedrock, or strongly cohesive sediments. No implication for the presence or absence of organic materials or living matter is intended. Soil contains local and regional materials mixed with the globally distributed dust by aeolian processes. Loose, unconsolidated surface materials (dust and soil) may pose challenges for human exploration on Mars. Dust will no doubt adhere to spacesuits, vehicles, habitats, and other surface systems. What will be the impacts on human activity? The objective of this paper is to review the chemical, mineralogical, and physical properties of the martian dust and soil.

  4. Surface roughness and chemical properties of porous inorganic films

    Energy Technology Data Exchange (ETDEWEB)

    Eggen, Carrie L.; McAfee, Paul M. [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287 (United States); Jin, Yi [China Electric Power Research Institute, Beijing 100192 (China); Lin, Y.S., E-mail: jerry.lin@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287 (United States)

    2015-09-30

    Porous inorganic films of different materials and pore architecture: mesoporous γ-alumina, mesoporous yttria stabilized zirconia (YSZ), macroporous YSZ and macroporous/microporous zeolite silicalite, were synthesized by the sol–gel spin-coating or dip-coating methods on silicon wafers of different surface roughness. Their surface chemical properties, pore and phase structure, and surface roughness were studied by various surface characterization methods. The pore sizes of these films are determined by their primary particle size. All the films studied are hydrophilic due to the presence of hydroxyl groups on the external crystallite surface, and their hydrophilicity increases in the order: macroporous YSZ < mesoporous YSZ < silicalite < γ-alumina. The γ-alumina films have highly smooth surfaces, while mesoporous YSZ, macroporous YSZ and silicalite films have similar surface roughness much rougher than γ-alumina films. The surface roughness of these coated films does not depend on the coating method, surface roughness of the substrate, surface chemistry or pore structure of the films. It is more controlled by the shape and size of the primary particles and aggregates in the sol or suspension from which the films are obtained. - Highlights: • Porous films of various pore structures are prepared by sol–gel methods. • γ-Alumina films have much smoother surface than thin films of other materials. • Film surface roughness is controlled by the shape and size of particles in the sols.

  5. Solubility properties of siloxane polymers for chemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Grate, J.W. [Pacific Northwest Lab., Richland, WA (United States); Abraham, M.H. [University College, London (United Kingdom)

    1995-05-01

    This paper discusses the factors governing the sorption of vapors by organic polymers. The principles have been applied in the past for designing and selecting polymers for acoustic wave sensors; however they apply equally well to sorption of vapors by polymers used on optical chemical sensors. A set of solvation parameters (a table is presented for various organic vapors) have been developed that describe the particular solubility properties of individual solute molecules; they are used in linear solvation energy relationships (LSER) that model the sorption process. LSER coefficients are tabulated for five polysiloxanes; so are individual interaction terms for each of the 5 polymers. Dispersion interactions play a major role in determining overall partition coefficients; the log L{sup 16} (gas-liquid partition coefficient of solute on hexadecane) value of vapors are important in determining overall sorption. For the detection of basic vapors such as organophosphates, a hydrogen-bond acidic polymers will be most effective at sorbing them. Currently, fiber optic sensors are being developed where the cladding serves as a sorbent layer to collect and concentrate analyte vapors, which will be detected and identified spectroscopically. These solubility models will be used to design the polymers for the cladding for particular vapors.

  6. Influence of ball milling on the particle size and antimicrobial properties of Tridax procumbens leaf nanoparticles.

    Science.gov (United States)

    Karthik, Subramani; Suriyaprabha, Rangaraj; Balu, Kolathupalayam Shanmugam; Manivasakan, Palanisamy; Rajendran, Venkatachalam

    2017-02-01

    The herbal nanoparticles were prepared from shade dried Tridax procumbens plant leaves employing ball milling technique using different process parameters, like ball ratio/size and milling time. The obtained nanoparticles were comprehensively characterised using X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, dynamic light scattering, scanning electron microscopy and antimicrobial analysis techniques. The crystallinity of the nanoparticles was retained without altering even though the particle size changes due to milling periods. The antibacterial activities of the prepared herbal nanoparticles against Staphylococcus aureus and Escherichia coli were explored to understand the influence of particle size on antimicrobial activities and their functional properties. The increase in ball ratio and milling time periods leads to a decrease in nanoparticle size from 114 to 45 nm which in turn increases the antimicrobial activities. The above study confirms that antimicrobial activity relies on nanoparticle size. The observed knowledge on influence of particle size on antimicrobial activities will help to optimise the production of potential herbal nanoparticles for different biomedical applications.

  7. Phytochemical Analysis and Antioxidant Property of Leaf Extracts of Vitex doniana and Mucuna pruriens

    Directory of Open Access Journals (Sweden)

    K. N. Agbafor

    2011-01-01

    Full Text Available Oxidative stress and impaired antioxidant system have been implicated in the pathophysiology of diverse disease states. The phytochemical screening and antioxidant property of fresh leaves of Vitex doniana and Mucuna pruriens, used in the management and treatment of various diseases, were studied. The extracts (ethanol and distilled water were screened for the presence of phytochemicals, and their inhibition of 2,2-diphenyl-1-picryl-hydrazyl (DPPH radical was used to evaluate their free radical scavenging activity. Liver levels of malondialdehyde (MDA, superoxide dismutase (SOD, and catalase (CAT in carbon tetrachloride- (CCl4 treated albino rats were also used to assess the antioxidant activity of the extracts. The animals were treated with 250 mg/kg body weight of the extracts for six consecutive days before a single dose (2.5 mL/kg body weight of CCl4. Vitamin C was used as the standard antioxidant. Phytochemical screening revealed the presence of saponins, tannins, anthraquinones, terpenoids, and flavonoids in all the extracts, while alkaloids were detected in extracts of Vitex doniana only, and cardiac glycosides occurred in extracts of Mucuna pruriens only. All the extracts inhibited DPPH radical in a concentration-dependent manner, water extract of Vitex doniana producing highest inhibition which was not significantly different (P>.05 from vitamin C. The extracts produced a significant decrease (P<.05 in liver MDA, while the levels of SOD and CAT significantly increased (P<.05 relative to the positive control. These results are an indication of antioxidant potential of the extracts and may be responsible for some of the therapeutic uses of these plants.

  8. Verticillium longisporum Infection Affects the Leaf Apoplastic Proteome, Metabolome, and Cell Wall Properties in Arabidopsis thaliana

    Science.gov (United States)

    Floerl, Saskia; Majcherczyk, Andrzej; Possienke, Mareike; Feussner, Kirstin; Tappe, Hella; Gatz, Christiane; Feussner, Ivo; Kües, Ursula; Polle, Andrea

    2012-01-01

    Verticillium longisporum (VL) is one of the most devastating diseases in important oil crops from the family of Brassicaceae. The fungus resides for much time of its life cycle in the extracellular fluid of the vascular system, where it cannot be controlled by conventional fungicides. To obtain insights into the biology of VL-plant interaction in the apoplast, the secretome consisting of the extracellular proteome and metabolome as well as cell wall properties were studied in the model Brassicaceae, Arabidopsis thaliana. VL infection resulted in increased production of cell wall material with an altered composition of carbohydrate polymers and increased lignification. The abundance of several hundred soluble metabolites changed in the apoplast of VL-infected plants including signalling and defence compounds such as glycosides of salicylic acid, lignans and dihydroxybenzoic acid as well as oxylipins. The extracellular proteome of healthy leaves was enriched in antifungal proteins. VL caused specific increases in six apoplast proteins (three peroxidases PRX52, PRX34, P37, serine carboxypeptidase SCPL20, α-galactosidase AGAL2 and a germin-like protein GLP3), which have functions in defence and cell wall modification. The abundance of a lectin-like, chitin-inducible protein (CILLP) was reduced. Since the transcript levels of most of the induced proteins were not elevated until late infection time points (>20 dpi), whereas those of CILLP and GLP3 were reduced at earlier time points, our results may suggest that VL enhances its virulence by rapid down-regulation and delay of induction of plant defence genes. PMID:22363647

  9. 有机肥与化肥配施对烤烟品质及土壤的影响%Effect of Applying Organic Fertilizer with Chemical Fertilizer on Flue-cured Tobacco Leaf Quality and Soil Fertility

    Institute of Scientific and Technical Information of China (English)

    王树会; 纳红艳; 陈发荣; 赵宪凤

    2011-01-01

    为了改善植烟土壤的理化性状,提高土壤质量,研究了在高肥力土壤上几种有机肥(秸秆、菜籽饼和猪粪)与化肥配施对烤烟品质及土壤的影响.结果表明:与单施化肥相比(对照),化肥+秸秆处理有利于烟株的生长发育和提高烟叶的产量产值和上等烟比例;而化肥+菜籽饼处理对烟株前期的生长表现不佳,尽管产量比单施化肥增加12%,但上等烟比例较低;化肥+猪粪处理处于两者之间.有机肥与化肥配施明显提高了烟叶中的总糖、还原糖、糖碱比、氮碱比以及钾含量,同时降低了烟叶中总氮、烟碱和氯离子含量,从而使烟叶中的化学成分得到协调和平衡.有机肥与化肥配施后增加了土壤中有机质、全氮、全磷、全钾和有效锌含量,在一定程度上改善了土壤的理化性状.%In order to improve the physicochemical characters and quality of soil, this experiment studies the effect of applying several organic fertilizers with chemical fertilizer on the flue-cured tobacco leaf quality and soil fertility. The results showed that straw mulch + chemical fertilizer treatment could not only improve tobacco growth and development, but also increase the yield and the ratio of super-grade tobacco leaves. While rapeseed cake + chemical fertilizer treatment impeded tobacco plant growth at the early stage. Although this treatment increased the yield by 12% compared with the CK, the ratio of super-grade leaves was relatively low. The effect of pig manure + chemical fertilizer treatment was between the above mentioned 2 treatments. Applying organic fertilizer with chemical fertilizer could distinctively increase the contents of total sugar, reduced sugar and potassium in leaves, and the ratios between sugar and nicotine, between nitrogen and nicotine. At the same time, it decreased the contents of total nitrogen, nicotine and chloride, thus to adjust and balance the chemical components in tobacco leaf

  10. Psychotria viridis: Chemical constituents from leaves and biological properties

    Directory of Open Access Journals (Sweden)

    DÉBORA B.S. SOARES

    Full Text Available ABSTRACT The phytochemical study of hexane, chloroform and methanol extracts from leaves of Psychotria viridis resulted in the identification of: the pentacyclic triterpenes, ursolic and oleanolic acid; the steroids, 24-methylene-cycloartanol, stigmasterol and β-sitosterol; the glycosylated steroids 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol; a polyunsaturated triterpene, squalene; the esters of glycerol, 1-palmitoylglycerol and triacylglycerol; a mixture of long chain hydrocarbons; the aldehyde nonacosanal; the long chain fat acids hentriacontanoic, hexadecanoic and heptadenoic acid; the ester methyl heptadecanoate; the 4-methyl-epi-quinate and two indole alkaloids, N,N-dimethyltryptamine (DMT and N-methyltryptamine. The chemical structures were determined by means of spectroscopic (IR, 1H and 13C NMR, HSQC, HMBC and NOESY and spectrometric (CG-MS and LCMS-ESI-ITTOF methods. The study of biologic properties of P. viridis consisted in the evaluation of the acetylcholinesterase inhibition and cytotoxic activities. The hexane, chloroform, ethyl acetate and methanol extracts, the substances 24-methylene-cycloartanol, DMT and a mixture of 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol showed cholinesterase inhibiting activity. This activity induced by chloroform and ethyl acetate extracts was higher than 90%. The methanol and ethyl acetate extracts inhibit the growth and/or induce the death of the tumor cells strains B16F10 and 4T1, without damaging the integrity of the normal cells BHK and CHO. DMT also demonstrated a marked activity against tumor cell strains B16F10 and 4T1.

  11. Chemical and mechanical properties of surfaces on the nanoscale

    Science.gov (United States)

    Broz, Margaret Elizabeth

    This research investigated the chemical and physical properties of materials on the nanoscale. Combinatorial atomic layer deposition was used to deposit conformal films with compositional gradients from 100% aluminum oxide to 100% zinc oxide. The films were characterized using ellipsometry, scanning electron microscopy and Auger electron spectroscopy to determine their thickness and composition, respectively. Atomic layer deposition was confirmed individually for aluminum oxide and zinc oxide. Combinatorial experiments confirmed the etching of ZnO by the trimethyl aluminum precursor, which was compensated for by adjusting the pulse sequence. Thin diamond-like carbon films were studied using scanning probe microscopy techniques (atomic force microscopy, friction force microscopy, digital pulsed force mode atomic force microscopy) and a method for quantifying the friction coefficient of these films was refined. Friction forces and the friction coefficient were measured for diamond-like carbon films over a range of relative humidity values and hysteresis effects were also studied. The adhesion changes due to fluorinated lubricant top coats on the diamond-like carbon were studied using digital pulsed force mode atomic force microscopy over a range of relative humidity values. Special diamond-like carbon coated tips were used in both sets of experiments to simulate the head-disk interaction between the slider and media in hard disk drive systems. Monodisperse oleic acid-capped lead selenide nanocrystals were synthesized using a modified hot injection method. Size-tunable nanocrystals were obtained by adjusting synthetic parameters. Nanocrystals were analyzed using X-ray diffraction, absorbance spectroscopy and UV-Visible spectroscopy. Organic ligands were also synthesized and used in ligand exchange experiments. Drop cast films of the nanocrystals with new ligands showed some change in FTIR peak position.

  12. Larvicidal and phytochemical properties of Callistemon rigidus R. Br. (Myrtaceae leaf solvent extracts against three vector mosquitoes

    Directory of Open Access Journals (Sweden)

    Danga Yinyang Simon Pierre

    2014-08-01

    Full Text Available Background & objectives: Due to ever-growing insecticide resistance in mosquito vectors and environmental contamination by synthetic insecticides, plants may be a source of alternative agents for mosquito control. Therefore, the present investigation involved the determination of larvicidal and phytochemical properties of Callistemon rigidus leaf extracts against Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. Methods: The standard protocol of WHO was used for larval tests. Twenty five IV instar larvae were exposed to various concentrations from 125-1000 ppm for methanol crude extract (MCE, hexane (HF, chloroform (CF, ethyl acetate (EAF and methanol (MF fractions, from 250-2000 ppm for aqueous extract (AE and 2500 ppm for Diclorvos. The mortality was observed 24 h post-exposure. The LC50 and LC90 values were determined by Probit analysis. Results: The phytochemical analysis revealed that the presence of alkaloids, steroids, saponins, terpenoids, tannins and phenolic compounds, lipids, fats and fixed oils in MCE; terpenoids, steroids, lipids, fats and fixed oils in HF; terpenoids in CF; tannins and phenolic compounds in EAF and alkaloids, tannins, saponins and phenolic compounds in MF. Against Ae. aegypti, HF was the most active fraction with LC50 of 56.25 ppm. Against An. gambiae, HF demonstrated its potential mosquito larvicide killing relatively all exposed larvae at all concentrations with LC50 of 17.11 ppm. Against Cx. quinquefasciatus, only MCE and HF exhibited larvicidal activity with LC50 of 447.38 and 721.95 ppm, respectively. Interpretation & conclusion: Callistemon rigidus exhibited some promising larvicidal activity against medically important vector mosquitoes. Studies are indicated to identify the active compounds from this plant for developing mosquito larvicides

  13. Mental Rolodexing: Senior Chemistry Majors' Understanding of Chemical and Physical Properties

    Science.gov (United States)

    DeFever, Ryan S.; Bruce, Heather; Bhattacharyya, Gautam

    2015-01-01

    Using a constructivist framework, eight senior chemistry majors were interviewed twice to determine: (i) structural inferences they are able to make from chemical and physical properties; and (ii) their ability to apply their inferences and understandings of these chemical and physical properties to solve tasks on the reactivity of organic…

  14. Chemical Composition and Antimicrobial Potential of Palm Leaf Extracts from Babaçu (Attalea speciosa, Buriti (Mauritia flexuosa, and Macaúba (Acrocomia aculeata

    Directory of Open Access Journals (Sweden)

    Adriana Idalina Torcato de Oliveira

    2016-01-01

    Full Text Available Babaçu (A. speciosa, Buriti (M. flexuosa, and Macaúba (A. aculeata are palm trees typical of the ecotone area between Cerrado and the Amazon rainforest. The purpose of this study was to evaluate the antimicrobial potential of the extracts prepared from the leaves of those palms as well as determine their chemical compositions. The ethanol extracts were prepared in a Soxhlet apparatus and tested by disk diffusion and agar dilution technique against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Candida parapsilosis. However, there was no significant activity at concentrations of 25, 50, and 100 mg·Ml−1. Moreover, the phytochemical analysis revealed the presence of tannins, flavonoids, catechins, steroids, triterpenes, and saponins. Gas chromatography (GC/MS analysis also identified organic acids, such as capric (decanoic acid, lauric (dodecanoic acid, myristic (tetradecanoic acid, phthalic (1,2-benzenedicarboxylic acid, palmitic (hexadecanoic acid, stearic (octadecanoic acid, linoleic (9,12-octadecadienoic acid (omega-6, linolenic (octadecatrienoic acid (omega-3, and the terpenes citronellol and phytol. Based on the chemical composition in the palm leaf extracts, the palms have the potential to be useful in the food, cosmetic, and pharmaceutical industries.

  15. Chemical Composition and Antimicrobial Potential of Palm Leaf Extracts from Babaçu (Attalea speciosa), Buriti (Mauritia flexuosa), and Macaúba (Acrocomia aculeata)

    Science.gov (United States)

    Mahmoud, Talal Suleiman; do Nascimento, Guilherme Nobre L.; da Silva, Juliana Fonseca Moreira

    2016-01-01

    Babaçu (A. speciosa), Buriti (M. flexuosa), and Macaúba (A. aculeata) are palm trees typical of the ecotone area between Cerrado and the Amazon rainforest. The purpose of this study was to evaluate the antimicrobial potential of the extracts prepared from the leaves of those palms as well as determine their chemical compositions. The ethanol extracts were prepared in a Soxhlet apparatus and tested by disk diffusion and agar dilution technique against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Candida parapsilosis. However, there was no significant activity at concentrations of 25, 50, and 100 mg·Ml−1. Moreover, the phytochemical analysis revealed the presence of tannins, flavonoids, catechins, steroids, triterpenes, and saponins. Gas chromatography (GC/MS) analysis also identified organic acids, such as capric (decanoic) acid, lauric (dodecanoic) acid, myristic (tetradecanoic) acid, phthalic (1,2-benzenedicarboxylic) acid, palmitic (hexadecanoic) acid, stearic (octadecanoic) acid, linoleic (9,12-octadecadienoic) acid (omega-6), linolenic (octadecatrienoic) acid (omega-3), and the terpenes citronellol and phytol. Based on the chemical composition in the palm leaf extracts, the palms have the potential to be useful in the food, cosmetic, and pharmaceutical industries. PMID:27529077

  16. Chemical Composition and Antimicrobial Potential of Palm Leaf Extracts from Babaçu (Attalea speciosa), Buriti (Mauritia flexuosa), and Macaúba (Acrocomia aculeata).

    Science.gov (United States)

    de Oliveira, Adriana Idalina Torcato; Mahmoud, Talal Suleiman; do Nascimento, Guilherme Nobre L; da Silva, Juliana Fonseca Moreira; Pimenta, Raphael Sanzio; de Morais, Paula Benevides

    2016-01-01

    Babaçu (A. speciosa), Buriti (M. flexuosa), and Macaúba (A. aculeata) are palm trees typical of the ecotone area between Cerrado and the Amazon rainforest. The purpose of this study was to evaluate the antimicrobial potential of the extracts prepared from the leaves of those palms as well as determine their chemical compositions. The ethanol extracts were prepared in a Soxhlet apparatus and tested by disk diffusion and agar dilution technique against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Candida parapsilosis. However, there was no significant activity at concentrations of 25, 50, and 100 mg·Ml(-1). Moreover, the phytochemical analysis revealed the presence of tannins, flavonoids, catechins, steroids, triterpenes, and saponins. Gas chromatography (GC/MS) analysis also identified organic acids, such as capric (decanoic) acid, lauric (dodecanoic) acid, myristic (tetradecanoic) acid, phthalic (1,2-benzenedicarboxylic) acid, palmitic (hexadecanoic) acid, stearic (octadecanoic) acid, linoleic (9,12-octadecadienoic) acid (omega-6), linolenic (octadecatrienoic) acid (omega-3), and the terpenes citronellol and phytol. Based on the chemical composition in the palm leaf extracts, the palms have the potential to be useful in the food, cosmetic, and pharmaceutical industries.

  17. Development of a novel cup cake with unique properties of essential oil of betel leaf (Piper betle L.) for sustainable entrepreneurship.

    Science.gov (United States)

    Roy, Arnab; Guha, Proshanta

    2015-08-01

    Betel vine (Piper betle L.) is a root climber with deep green heart shaped leaves. It belongs to the Piperaceae family. There is a huge wastage of the leaves during glut season and it can be reduced by various means including extraction of medicinal essential oil which can be considered as GRAS (generally recognized as safe) materials. Therefore, attempts were made to develop a novel cup cake by incorporating essential oil of betel leaf. The textural properties of the cakes were measured by texture analyzer instrument; whereas the organoleptic properties were adjudged by human preferences using sensory tables containing 9-point hedonic scale. Price estimation was done considering all costs and charges. Finally, all parameters of the developed cake were compared with different cup cakes available in the market for ascertaining consumer acceptability of the newly developed product in terms of quality and market price. Results revealed that the Novel cup cake developed with 0.005 % (v/w) essential oil of betel leaf occupied the 1st place among the four developed novel cup cakes. However, it occupied 4th place among the nine cup cakes in the overall preference list prepared based on the textural and organoleptic qualities, though its market price was calculated to be comparable to all the leading cupcakes available in the market. This indicates that manufacturing of novel cup cake with essential oil of betel leaf would be a profitable and self-sustaining entrepreneurship.

  18. Anti-Inflammatory Activity and Changes in Antioxidant Properties of Leaf and Stem Extracts from Vitex mollis Kunth during In Vitro Digestion

    Directory of Open Access Journals (Sweden)

    Juan Alfredo Morales-Del-Rio

    2015-01-01

    Full Text Available Vitex mollis is used in traditional Mexican medicine for the treatment of some ailments. However, there are no studies on what happens to the anti-inflammatory activity or antioxidant properties and total phenolic content of leaves and stem extracts of Vitex mollis during the digestion process; hence, this is the aim of this work. Methanolic, acetonic, and hexanic extracts were obtained from both parts of the plant. Extract yields and anti-inflammatory activity (elastase inhibition were measured. Additionally, changes in antioxidant activity (DPPH and ABTS and total phenols content of plant extracts before and after in vitro digestion were determined. The highest elastase inhibition to prevent inflammation was presented by hexanic extracts (leaf = 94.63% and stem = 98.30%. On the other hand, the major extract yield (16.14%, antioxidant properties (ABTS = 98.51% and DPPH = 94.47% of inhibition, and total phenols (33.70 mg GAE/g of dried sample were showed by leaf methanolic extract. Finally, leaf and stem methanolic extracts presented an antioxidant activity increase of 35.25% and 27.22%, respectively, in comparison to their initial values after in vitro digestion process. All samples showed a decrease in total phenols at the end of the digestion. These results could be the basis to search for new therapeutic agents from Vitex mollis.

  19. Antioxidant and antimicrobial properties of Teucrium arduini L. (Lamiaceae) flower and leaf infusions (Teucrium arduini L. antioxidant capacity).

    Science.gov (United States)

    Samec, D; Gruz, J; Strnad, M; Kremer, D; Kosalec, I; Grubesić, R Jurisić; Karlović, K; Lucic, A; Piljac-Zegarac, J

    2010-01-01

    Antioxidant and antimicrobial activities, as well as total phenol (TP, Folin-Ciocalteu method) and phenolic acid (UPLC-MS/MS) contents of leaf and flower infusions of Teucrium arduini L. from six different mountainous localities in Croatia (Ucka, Vosac, Sveti Jure, Snjeznica, Vaganac, Susanj) were analysed in this study. Antioxidant capacity was evaluated using the ferric reducing/antioxidant power (FRAP) assay, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. The antioxidant potency composite index (ACI), giving equal weight to all three methods used to quantify antioxidant capacity, was the highest for the sample from Vosac (96.7) among flower infusions, while maximum ACI (100) was determined for the infusion from Ucka among leaf infusions. Strong positive correlation was found between the total phenols and ACI for leaf (r=0.953) and flower (r=0.977) infusions. Our results point to significantly (p<0.05) different TP content between leaf and flower infusions, as well as across localities. Leaf infusions of T. arduini from Susanj exhibited marked antibacterial activity against Staphylococcus aureus, while none of the tested infusions exhibited antimicrobial activity against gram-negative bacterial species, or the tested fungal species.

  20. [Assessment of the relationship of properties of chemical compounds and their toxicity to a unified hygienic standardization for chemicals].

    Science.gov (United States)

    Trushkov, V F; Perminov, K A; Sapozhnikova, V V; Ignatova, O L

    2013-01-01

    The connection of thermodynamic properties and parameters of toxicity of chemical substances was determined. Obtained data are used for the evaluation of toxicity and hygienic rate setting of chemical compounds. The relationship between enthalpy and toxicity of chemical compounds has been established. Orthogonal planning of the experiment was carried out in the course of the investigations. Equation of unified hygienic rate setting in combined, complex, conjunct influence on the organism is presented. Prospects of determination of toxicity and methodology of unified hygienic rate setting in combined, complex, conjunct influence on the organism are presented

  1. Evaluation of phytochemical properties and in-vitro antibacterial activity of the aqueous extracts of leaf, seed and root of Abrus precatorius Linn. against Salmonella and Shigella

    Institute of Scientific and Technical Information of China (English)

    Ojo Joseph Sunday; Shola Kola Babatunde; Adeyinka Elizabeth Ajiboye; Racheal Majekodunmi Adedayo; Mufutau Adeyemi Ajao; Busayo Isreal Ajuwon

    2016-01-01

    Objective: To investigate the phytochemical components of Abrus precatorius (A. precatorius) and the in-vitro susceptibility of Salmonella typhi and Shigella dysen-teriae to the aqueous extracts of A. precatorius leaf, seed and root. Methods: The leaf, seed and root of A. precatorius were collected and homogenized separately after drying at 40 °C for seven days in hot-air oven. The aqueous extracts of each of the parts were prepared and subjected to phytochemical screening. Dilutions of 400, 300, 200, 100 mg/mL, of each of the extracts were used for broth dilution in minimum inhibitory concentration (MIC) determination against clinical isolates of Sal-monella typhi and Shigella dysenteriae, while 50, 40, 30, 20, and 10 mg/mL dilutions were used for the agar diffusion test and 100μg/mL and 10μg/mL of gentamycin were used as controls for broth dilution in MIC determination and agar diffusion test, respectively. Results: Qualitative study reveals that tannin, saponins, alkaloids, flavonoids, terpe-noids, steroids and phenols were present in all of the plant parts. The leaf has the highest quantities of tannin and phenol. The root generally showed the lowest quantity of all the compounds. The pathogens were susceptible to aqueous extracts of the leaf, stem and root of A. precatorius at 50 mg/mL. At concentrations of 40, 30 and 20 mg/mL, all the aqueous extracts of A. precatorius showed variation in MIC, but produced no minimum bactericide effect upon subculture. There were variations in diameter of zone of inhibition against the organisms at lower concentrations. Conclusions: These findings suggest that A. precatorius is a valuable source of phyto-chemicals with promising antibacterial activity. Considering this bioactivity, A. precatorius could be probed further for toxicity, and to obtain some novel antibacterial molecules.

  2. Investigation into the physico-chemical properties and ...

    African Journals Online (AJOL)

    user

    organic and/or chemical pollutants (Bartran and Balance,. 1996). .... Jones (1998) reported that acidic water results in .... maintenance of acid - base balance, and hence ..... United States Environmental Protection Agency (USEPA) (2002).

  3. Effect of ozone gas processing on physical and chemical properties ...

    African Journals Online (AJOL)

    The physical and chemical ... Results: Sulfhydryl group contents of wheat proteins ranged from 1.1 to 7.12 µmol/g. Sulfhydryl ... provide cohesion and are responsible for the extensibility of ..... Higher Education Institutions, Wuxi City, Jiangsu.

  4. Chemical composition and insecticidal properties of essential oil ...

    African Journals Online (AJOL)

    chromatography/mass spectrometry (GC/MS) analysis was performed, and the contact (topical application) ... Results: Thirty-nine chemical compounds were identified by GC-MS analysis of M. .... negative control, and pyrethrum extract (25 %.

  5. physico-chemical properties of well water samples from some ...

    African Journals Online (AJOL)

    Administrator

    Physico-Chemical Analysis: Water samples collected were analyzed by both classical and .... This and some other factors may be responsible for the ... Diatom (Bacillariophyta) diversity of an open access lagoon in. Lagos, Nigeria. Journal ...

  6. Evaluation of some microbial agents, natural and chemical compounds for controlling tomato leaf miner, Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae

    Directory of Open Access Journals (Sweden)

    Abd El-Ghany Nesreen M.

    2016-12-01

    Full Text Available Solanaceous plants have a great economic impact in Egypt. These groups of plants include potatoes, tomatoes and eggplants. The new invasive pest of tomatoes, Tuta absoluta (Meyrick causes the greatest crop losses which can range from 60 to 100%. After its detection in Egypt during the last half of 2009, it spread quickly to all provinces in the country. We aiming to propose a sustainable control program for this devastating pest. In this research we tested three groups of control agents. The first was microbial and natural, the second - plant extracts and the third - chemical insecticides. Our results showed that the impact of T. absoluta can be greatly reduced by the use of sustainable control measures represented by different insecticide groups. Bioassay experiments showed that this devastating pest can be controlled with some compounds that give high mortality rates. Of these compounds, spinosad and Beauveria bassiana, microbial control agents, followed by azadirachtin, gave the best results in controlling T. absoluta. Of the chemical insecticides, lambda-cyhalotrin was the most effective, followed by lufenuron and profenofos. In conclusion we encourage farmers to use microbial and natural control measures in combating the tomato leafminer, T. absoluta, in Integrated Pest Mangement (IPM programs.

  7. The influence of liming on soil chemical properties and on the alleviation of manganese and copper toxicity in Juglans regia, Robinia pseudoacacia, Eucalyptus sp. and Populus sp. plantations.

    Science.gov (United States)

    Chatzistathis, T; Alifragis, D; Papaioannou, A

    2015-03-01

    Juglans regia, Robinia pseudoacacia, Eucalyptus sp. and Populus sp. plantations, suffering from Mn and Cu toxicity, were limed in order to reduce Cu and Mn solubility in soil. The purposes of the present work were: i) to study the changes in soil chemical properties after the addition of CaCO3, ii) to investigate the influence of liming on the reduction of Mn and Cu toxicity. After the addition of CaCO3 (three applications, during three successive years), pH and CaCO3 content were significantly increased, while organic C and N were significantly reduced. Exchangeable Ca concentrations have been slightly, or significantly, increased, while those of Mg have been decreased; in addition, ratios Ca/Mg and C/N have been significantly increased after liming. Impressive reductions of DTPA extractable Cu and Mn concentrations (more than 10 times in most cases) were recorded. It was also found that trees without Mn and Cu toxicity symptoms (healthy tress) before liming did not have, in many cases, significantly greater leaf Mn, Cu and Fe concentrations, than trees after soil liming (all the trees were healthy). This probably happened because excess Mn and Cu quantities had been accumulated into their root system. Finally, leaf Mn, Cu and Zn concentrations of trees suffering from toxicity were significantly decreased after soil liming, while leaf Fe concentrations, in all the plant species studied, were increased.

  8. Modification of chemical properties of cell walls by silicon and its role in regulation of the cell wall extensibility in oat leaves.

    Science.gov (United States)

    Hossain, Mohammad Talim; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Fujii, Shuhei; Yamamoto, Ryoichi; Hoson, Takayuki

    2007-04-01

    Effects of silicon on the mechanical and chemical properties of cell walls in the second leaf of oat (Avena sativa L.) seedlings were investigated. The cell wall extensibility in the basal region of the second leaf was considerably higher than that in the middle and subapical regions. Externally applied silicon increased the cell wall extensibility in the basal region, but it did not affect the extensibility in the middle and subapical regions. The amounts of cell wall polysaccharides and phenolic compounds, such as diferulic acid (DFA) and ferulic acid (FA), per unit length were lower in the basal region than in the middle and subapical regions of the leaf, and silicon altered these amounts in the basal region. In this region, silicon decreased the amounts of matrix polymers and cellulose per unit length and of DFA and FA, both per unit length and unit matrix polymer content. Silicon treatment also lowered the activity of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) in the basal region. In contrast, the amount of silicon in cell walls increased in response to silicon treatment in three regions. These results suggest that in the basal region, silicon reduces the net wall mass and the formation of phenolic acid-mediated cross-linkages between wall polysaccharides. Such modifications of wall architecture may be responsible for the silicon-induced increase in the cell wall extensibility in oat leaves.

  9. Physico-chemical properties of perturbed water: facts and enigmas

    Directory of Open Access Journals (Sweden)

    Vittorio Elia

    2012-09-01

    Full Text Available Background The study of extremely diluted and agitated substances and solutions is strictly linked with the analysis of properties of water perturbed using different systems. This study is about the determination of the physical-chemical parameters of water, after the perturbations described. Methods The perturbed water was obtained using the three different protocols: · EDS (Extremely Diluted Solutions. Obtained through an iterative process of successive dilutions and agitations. · IFW (Iteratively Filtered Water. Obtained through an iterative process of successive filtrations through sintered glass filters. · INW (Iteratively Nafionized Water. Obtained through an iterative process of successive drying and wetting of the Nafion polymer. The parameters under study are: electrical conductivity, χ / μS cm-1; heat of mixing with acid (HCl, ΔQmixHCl / J Kg-1 or basic (NaOH solutions, ΔQmixNaOH / J Kg-1 and pH. χ increases of up to two orders of magnitude, ΔQmixNaOH / J Kg-1 is exothermic and increases as the electrical conductivity increases, with a roughly linear trend, up to one order of magnitude. The analogous ΔQmixHCl / J Kg-1, on the contrary, is found to be exothermic or null depending on the protocol used. For the two protocol (EDS or IFW the pH is alkaline while for the third one (INW is quite acid and shows a very good linear correlation with logχ. The linear correlations hint at a single cause for the variation of the three very different physical- chemical parameters. Results and discussion Each protocol produces water exhibiting its own peculiarities, to the point that they can be considered different, albeit with the common element of a variation of the super-molecular structure of the water solvent. These three procedures capable of affecting water can be grouped together by means of a common work

  10. Potential Impacts of Spilled Hydraulic Fracturing Fluid Chemicals on Water Resources: Types, volumes, and physical-chemical properties of chemicals

    Science.gov (United States)

    Hydraulic fracturing (HF) fluid chemicals spilled on-site may impact drinking water resources. While chemicals generally make up <2% of the total injected fluid composition by mass, spills may have undiluted concentrations. HF fluids typically consist of a mixture of base flui...

  11. Computer program for calculation of thermodynamic and transport properties of complex chemical systems

    Science.gov (United States)

    Svehla, R. A.; Mcbride, B. J.

    1973-01-01

    Program performs calculations such as chemical equilibrium for assigned thermodynamic states, theoretical rocket performance for both equilibrium and frozen compositions during expansion, incident and reflected shock properties, and Chapman-Jouget detonation properties. Features include simplicity of input and storage of all thermodynamic and transport property data on master tape.

  12. Effect of Chemical Structure on Molecular Properties of Hyperbranched Polycarbosilanes

    Institute of Scientific and Technical Information of China (English)

    E.Tarabukina; A.Shpyrkov; A.Amirova; E.Tarasova; N.Shumilkina; A.Filippov; A.Muzafarov

    2007-01-01

    1 Results In spite of the increased interest to the synthesis of hyperbranched polymers,there is a lack of studies of conformational properties of their macromolecules.Structural features of hyperbranched polymers are responsible for new properties that distinguish them from linear compounds and open unique possibilities for their applications.The knowledge of the "structure-properties" relationships is of fundamental value,it also can be helpful when developing new technologies and new materials. The g...

  13. Effects of different chemical additives on biodiesel fuel properties and engine performance. A comparison review

    Directory of Open Access Journals (Sweden)

    Ali Obed Majeed

    2016-01-01

    Full Text Available Biodiesel fuel can be used as an alternative to mineral diesel, its blend up to 20% used as a commercial fuel for the existing diesel engine in many countries. However, at high blending ratio, the fuel properties are worsening. The feasibility of pure biodiesel and blended fuel at high blending ratio using different chemical additives has been reviewed in this study. The results obtained by different researchers were analysed to evaluate the fuel properties trend and engine performance and emissions with different chemical additives. It found that, variety of chemical additives can be utilised with biodiesel fuel to improve the fuel properties. Furthermore, the chemical additives usage in biodiesel is inseparable both for improving the cold flow properties and for better engine performance and emission control. Therefore, research is needed to develop biodiesel specific additives that can be adopted to improve the fuel properties and achieve best engine performance at lower exhaust emission effects.

  14. Leaf-fracture properties correlated with nutritional traits in nine Australian seagrass species: implications for susceptibility to herbivory

    NARCIS (Netherlands)

    de los Santos, C.B.; Brun, F.G.; Onoda, Y.; Cambridge, M.L.; Bouma, T.J.; Vergara, J.J.; Pérez-Lloréns, J.L.

    2012-01-01

    Seagrasses are exposed to the constant risk of structural damage due to abiotic factors, such as waves and currents, and biotic factors, e. g. herbivory. Leaf mechanical resistance is therefore essential in protecting plants from structural failure and may also have ecological consequences. For exam

  15. Variation in light absorption properties of mentha aquatica L. as a function of leaf form: Implications for plant growth

    DEFF Research Database (Denmark)

    Enriquez, Susana; Jensen, Kaj Sand

    2008-01-01

    area increased. This relationship indicates that dispersive samples, such as leaves, although efficient light traps, can also be affected by the "package effect." Mentha aquatica leaves, by expanding their biomass (increased specific leaf area [SLA]), improve their light absorption efficiency per unit...

  16. Chemical properties of 11 date cultivars and their corresponding ...

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... properties such as water holding capacity (WHC) and oil holding capacity (OHC). DFC presented high dietary fiber content (90.71 - 93.92 g/100g dry matter). Protein and lipid ... Dates are rich in certain nutrients such as fiber (≈ 8.1 ...... Relationship between physical and hydratation properties of soluble.

  17. Strategies of chemical anti-predator defences in leaf beetles: is sequestration of plant toxins less costly than de novo synthesis?

    Science.gov (United States)

    Zvereva, Elena L; Zverev, Vitali; Kruglova, Oksana Y; Kozlov, Mikhail V

    2017-01-01

    The evolution of defensive traits is driven both by benefits gained from protection against enemies and by costs of defence production. We tested the hypothesis that specialisation of herbivores on toxic host plants, accompanied by the ability to acquire plant defensive compounds for herbivore defence, is favoured by the lower costs of sequestration compared to de novo synthesis of defensive compounds. We measured physiological costs of chemical defence as a reduction in larval performance in response to repeated removal of secretions (simulating predator attack) and compared these costs between five species synthesising defences de novo and three species sequestering salicylic glucosides (SGs) from their host plants. Experiments simulating low predator pressure revealed no physiological costs in terms of survival, weight and duration of development in any of study species. However, simulation of high predation caused reduction in relative growth rate in Chrysomela lapponica larvae producing autogenous defences more frequently, than in larvae sequestering SGs. Still meta-analysis of combined data showed no overall difference in costs of autogenous and sequestered defences. However, larvae synthesising their defences de novo demonstrated secretion-conserving behaviour, produced smaller amounts of secretions, replenished them at considerably lower rates and employed other types of defences (regurgitation, evasion) more frequently when compared to sequestering larvae. These latter results provide indirect evidence for biosynthetic constraints for amounts of defensive secretions produced de novo, resulting in low defence effectiveness. Lifting these constraints by sequestration may have driven some leaf beetle lineages toward sequestration of plant allelochemicals as the main defensive strategy.

  18. Chemical and mechanical defenses vary among maternal lines and leaf ages in Verbascum thapsus L. (Scrophulariaceae and reduce palatability to a generalist insect.

    Directory of Open Access Journals (Sweden)

    Christina Alba

    Full Text Available Intra-specific variation in host-plant quality affects herbivore foraging decisions and, in turn, herbivore foraging decisions mediate plant fitness. In particular, variation in defenses against herbivores, both among and within plants, shapes herbivore behavior. If variation in defenses is genetically based, it can respond to natural selection by herbivores. We quantified intra-specific variation in iridoid glycosides, trichome length, and leaf strength in common mullein (Verbascum thapsus L, Scrophulariaceae among maternal lines within a population and among leaves within plants, and related this variation to feeding preferences of a generalist herbivore, Trichopulsia ni Hübner. We found significant variation in all three defenses among maternal lines, with T. ni preferring plants with lower investment in chemical, but not mechanical, defense. Within plants, old leaves had lower levels of all defenses than young leaves, and were strongly preferred by T. ni. Caterpillars also preferred leaves with trichomes removed to leaves with trichomes intact. Differences among maternal lines indicate that phenotypic variation in defenses likely has a genetic basis. Furthermore, these results reveal that the feeding behaviors of T. ni map onto variation in plant defense in a predictable way. This work highlights the importance of variation in host-plant quality in driving interactions between plants and their herbivores.

  19. Machine Learning of Molecular Electronic Properties in Chemical Compound Space

    CERN Document Server

    Montavon, Grégoire; Gobre, Vivekanand; Vazquez-Mayagoitia, Alvaro; Hansen, Katja; Tkatchenko, Alexandre; Müller, Klaus-Robert; von Lilienfeld, O Anatole

    2013-01-01

    The combination of modern scientific computing with electronic structure theory can lead to an unprecedented amount of data amenable to intelligent data analysis for the identification of meaningful, novel, and predictive structure-property relationships. Such relationships enable high-throughput screening for relevant properties in an exponentially growing pool of virtual compounds that are synthetically accessible. Here, we present a machine learning (ML) model, trained on a data base of \\textit{ab initio} calculation results for thousands of organic molecules, that simultaneously predicts multiple electronic ground- and excited-state properties. The properties include atomization energy, polarizability, frontier orbital eigenvalues, ionization potential, electron affinity, and excitation energies. The ML model is based on a deep multi-task artificial neural network, exploiting underlying correlations between various molecular properties. The input is identical to \\emph{ab initio} methods, \\emph{i.e.} nucle...

  20. Bioefficacy of larvicdial and pupicidal properties of Carica papaya (Caricaceae) leaf extract and bacterial insecticide, spinosad, against chikungunya vector, Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Kovendan, Kalimuthu; Murugan, Kadarkarai; Naresh Kumar, Arjunan; Vincent, Savariar; Hwang, Jiang-Shiou

    2012-02-01

    The present study was carried out to establish the properties of Carica papaya leaf extract and bacterial insecticide, spinosad on larvicidal and pupicidal activity against the chikungunya vector, Aedes aegypti. The medicinal plants were collected from the area around Bharathiar University, Coimbatore, India. C. papaya leaf was washed with tap water and shade-dried at room temperature. An electrical blender powdered the dried plant materials (leaves). The powder (500 g) of the leaf was extracted with 1.5 l of organic solvents of methanol for 8 h using a Soxhlet apparatus and then filtered. The crude leaf extracts were evaporated to dryness in a rotary vacuum evaporator. The plant extract showed larvicidal and pupicidal effects after 24 h of exposure; however, the highest larval and pupal mortality was found in the leaf extract of methanol C. papaya against the first- to fourth-instar larvae and pupae of values LC(50) = I instar was 51.76 ppm, II instar was 61.87 ppm, III instar was 74.07 ppm, and IV instar was 82.18 ppm, and pupae was 440.65 ppm, respectively, and bacterial insecticide, spinosad against the first to fourth instar larvae and pupae of values LC(50) = I instar was 51.76 ppm, II instar was 61.87 ppm, III instar was 74.07 ppm, and IV instar was 82.18 ppm, and pupae was 93.44 ppm, respectively. Moreover, combined treatment of values of LC(50) = I instar was 55.77 ppm, II instar was 65.77 ppm, III instar was 76.36 ppm, and IV instar was 92.78 ppm, and pupae was 107.62 ppm, respectively. No mortality was observed in the control. The results that the leaves extract of C. papaya and bacterial insecticide, Spinosad is promising as good larvicidal and pupicidal properties of against chikungunya vector, A. aegypti. This is an ideal eco-friendly approach for the control of chikungunya vector, A. aegypti as target species of vector control programs.

  1. SIFAT FISIK, KIMIA, DAN FUNGSIONAL DAMAR [Brief Review on: Physical, Chemical and Functional Properties of Dammar

    Directory of Open Access Journals (Sweden)

    Noryawati Mulyono1

    2004-12-01

    Full Text Available Dammar is one of Indonesian forestry products which is abundant. It has unique physical, chemical and functional properties. The important physical properties of dammar include its solubility in some organic solvents, softening temperature, viscosity and its absorbance. The important chemical properties reviewed here include its properties as resin, composition of terpenoid compounds present in dammar, and essential oil yielded from distillation of fresh dammar. Physical and chemical properties of dammar need to be studied further in order to optimize its functional properties. So far, dammar is widely used as weighting agent and source of essential oil. However, now, some species of dammar are being explored and developed for sal flour, fat source, triacylglycerol substituent for cocoa butter and wood preservatives.

  2. An ontology on property for physical, chemical, and biological systems.

    Science.gov (United States)

    Dybkaer, René

    2004-01-01

    Current metrological literature, including the International vocabulary of basic and general terms in metrology (VIM 1993), presents a special language slowly evolved without consistent use of the procedures of terminological work; furthermore, nominal properties are excluded by definition. Both deficiencies create problems in fields, such as laboratory medicine, which have to report results of all types of property, preferably in a unified systematic format. The present text aims at forming a domain ontology around "property", with intensional definitions and systematic terms, mainly using the terminological tools--with some additions--provided by the International Standards ISO 704, 1087-1, and 10241. "System" and "component" are defined, "quantity" is discussed, and the generic concept "property" is given as 'inherent state- or process-descriptive feature of a system including any pertinent components'. Previously, the term 'kind-of-quantity' and quasi-synonyms have been used as primitives; the proposed definition of "kind-of-property" is 'common defining aspect of mutually comparable properties'. "Examination procedure", "examination method", "examination principle", and "examination" are defined, avoiding the term 'test'. The need to distinguish between instances of "characteristic", "property", "type of characteristic", "kind-of-property", and "property value" is emphasized; the latter is defined together with "property value scale". These fundamental concepts are presented in a diagram, and the effect of adding essential characteristics to give expanded definitions is exemplified. Substitution usually leads to unwieldy definitions, but reveals circularity as does exhaustive consecutive listing of defining concepts. The top concept may be generically divided according to many terminological dimensions, especially regarding which operators are allowed among the four sets =, not equal to; ; +, -; and x, :. The coordinate concepts defined are termed by the

  3. EFFECT OF DEEP-FAT FRYING ON CHEMICAL PROPERTIES OF ...

    African Journals Online (AJOL)

    diopamadr

    common method of preparing dishes in Senegalese culinary practices. ... The purpose of this study was to evaluate the effect of frying on chemical ... Materials used for preparation and analysis consisted of conventional laboratory ..... Measurement of total polar components (TP) is useful in estimating heat misuse in.

  4. Technological and chemical properties of heat-treated Anatolian ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... chemical content and cellulose crystallinity of Anatolian black pine [Pinus nigra J.F. Arnold subsp. .... was determined as acid-insoluble Klason lignin by Runkel method ..... crystalline structure of cellulose using static and dynamic FT-IR ... different models for the high-temperature heat-treatment of wood. Int.

  5. Physico-chemical properties of radionuclides emitted as particulate matter

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann

    2016-01-01

    This paper presents work done to improve the representation in European decision support tools of physico-chemical forms of radiocontaminants released to the atmosphere from a major nuclear power plant accident. The task is to accommodate those types of scenarios where fuel particles are at play...

  6. Physico-Chemical Properties of Nanoparticles Functionalized by Polypyrrole

    Directory of Open Access Journals (Sweden)

    Yu.A. Mirgorod

    2013-12-01

    Full Text Available Мagnetite nanoparticles coated with polypyrrole have been synthesized. Nanocomposite powder has been investigated by FTIR, XRD, SEM, magnetometry, conductivity measurements. Polypyrrole in nanocomposite does not impair the magnetic properties of magnetite.

  7. Medicinal chemical properties of successful central nervous system drugs.

    Science.gov (United States)

    Pajouhesh, Hassan; Lenz, George R

    2005-10-01

    Fundamental physiochemical features of CNS drugs are related to their ability to penetrate the blood-brain barrier affinity and exhibit CNS activity. Factors relevant to the success of CNS drugs are reviewed. CNS drugs show values of molecular weight, lipophilicity, and hydrogen bond donor and acceptor that in general have a smaller range than general therapeutics. Pharmacokinetic properties can be manipulated by the medicinal chemist to a significant extent. The solubility, permeability, metabolic stability, protein binding, and human ether-ago-go-related gene inhibition of CNS compounds need to be optimized simultaneously with potency, selectivity, and other biological parameters. The balance between optimizing the physiochemical and pharmacokinetic properties to make the best compromises in properties is critical for designing new drugs likely to penetrate the blood brain barrier and affect relevant biological systems. This review is intended as a guide to designing CNS therapeutic agents with better drug-like properties.

  8. Tuning the NLO properties of polymethineimine chains by chemical substitution

    Energy Technology Data Exchange (ETDEWEB)

    Medved’, Miroslav, E-mail: miroslav.medved@umb.sk [Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, SK-97400 Banská Bystrica (Slovakia); Jacquemin, Denis [CEISAM, UMR CNRS 6230, BP 92208, Université de Nantes, 2, rue de la Houssinière, 44322 Nantes Cedex 3 (France); Institut Universitaire de France, 103, bd Saint-Michel, F-75005 Paris Cedex 05 (France)

    2013-03-29

    Highlights: ► Properties of the most stable isomers of polymethineimine (PMI) are investigated. ► 2nd order NLO properties of experimentally known PMI derivatives are determined. ► Structure-property relationships are unraveled for several series of oligomers. ► Performance of long-range corrected DFT methods is assessed. - Abstract: Structure and molecular electronic properties including dipole moment, polarizability and first hyperpolarizability of polymethineimine (PMI) oligomers (up to hexadecamers) and its experimentally known amino-, methyl-, and cyano-derivatives are investigated using several ab initio methods (HF, MP2 and DFT). It is shown that side-chain substitutions have significant effects both on the structure and molecular properties of PMI chains. Depending on the substitution, two types of structures have been identified. The first is characterized by a bent skeleton and encompasses PMI, polyacetonitrile (PAcN), and polycyanonitrile (PCN). The second, represented by polyaminonitrile (PAN), remains quasi-linear with the plane of the unit cell (UC) only slightly rotating around the longitudinal molecular axis. These structural differences are also reflected in molecular properties; while in case of PMI, PAcN, and PCN the longitudinal component of properties (reduced per UC) reaches its maximum value for medium-size oligomers and then decreases for longer chains, the linear and nonlinear properties of PAN steadily increase towards the polymeric limit. In addition, we have assessed the performances of long-range corrected DFT functionals (LR-DFT), namely LC-BLYP, CAM-B3LYP, and ωB97X within the present framework: they provide results in qualitative agreement with MP2, a success not reached with B3LYP.

  9. PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC

    Science.gov (United States)

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  10. the effect of rubber effluent on some chemical properties of soil and ...

    African Journals Online (AJOL)

    DR. AMINU

    on some soil chemical properties as well as early growth and nutrient uptake by ... plant were significantly higher (P<0.05) in rubber effluent treated plant than the .... The electrical conductivity ... (creep, crumb and concentrate latex) the effluent.

  11. Characterization of Electrochemical and Morphological Properties of Iron-Phosphate-Silicate Chemical Garden Structures

    Science.gov (United States)

    Doloboff, I. J.; Barge, L. M.; Russell, M. J.; Kanik, I.

    2012-03-01

    Examination of the growth of Fe^2^+, phosphate, and silicate chemical garden structures to understand properties of similar structures that may have formed at Hadean alkaline hydrothermal vents which may play an important role in the emergence of life.

  12. Identification of Patchouli–Chemical Properties on Oil Purification by Using Acid-Activated Bentonite

    National Research Council Canada - National Science Library

    Netty Sri Indeswari

    2015-01-01

    This research is aimed at obtaining –oil chemical properties on purification that include solubility in alcohol, total acid, total ester, Fe Content, Patchouli Alcohol Content, Alpha Copaene (C15H24...

  13. PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC

    Science.gov (United States)

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  14. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

  15. Amphibian and benthic macroinvertebrate response to physical and chemical properties of Themi River, Arusha, Tanzania

    OpenAIRE

    Lyimo, Emmanuel

    2012-01-01

    I hypothesized that variation in physical and chemical properties and habitat destruction of the Themi River as a result of human activities would affect abundance and diversity of amphibian and benthic macroinvertebrates. Variation in habitat physical and chemical conditions, and amphibian and benthic macroinvertebrate diversity and abundance were assessed in the Themi River of Arusha municipality. These physical, chemical and biological conditions were assessed at forty sampling stations...

  16. Tuning the NLO properties of polymethineimine chains by chemical substitution

    Science.gov (United States)

    Medved', Miroslav; Jacquemin, Denis

    2013-03-01

    Structure and molecular electronic properties including dipole moment, polarizability and first hyperpolarizability of polymethineimine (PMI) oligomers (up to hexadecamers) and its experimentally known amino-, methyl-, and cyano-derivatives are investigated using several ab initio methods (HF, MP2 and DFT). It is shown that side-chain substitutions have significant effects both on the structure and molecular properties of PMI chains. Depending on the substitution, two types of structures have been identified. The first is characterized by a bent skeleton and encompasses PMI, polyacetonitrile (PAcN), and polycyanonitrile (PCN). The second, represented by polyaminonitrile (PAN), remains quasi-linear with the plane of the unit cell (UC) only slightly rotating around the longitudinal molecular axis. These structural differences are also reflected in molecular properties; while in case of PMI, PAcN, and PCN the longitudinal component of properties (reduced per UC) reaches its maximum value for medium-size oligomers and then decreases for longer chains, the linear and nonlinear properties of PAN steadily increase towards the polymeric limit. In addition, we have assessed the performances of long-range corrected DFT functionals (LR-DFT), namely LC-BLYP, CAM-B3LYP, and ωB97X within the present framework: they provide results in qualitative agreement with MP2, a success not reached with B3LYP.

  17. Do climate and soil influence phenotypic variability in leaf litter, microbial decomposition and shredder consumption?

    Science.gov (United States)

    Graça, M A S; Poquet, J M

    2014-03-01

    We tested the hypothesis that water stress and soil nutrient availability drive leaf-litter quality for decomposers and detritivores by relating chemical and physical leaf-litter properties and decomposability of Alnus glutinosa and Quercus robur, sampled together with edaphic parameters, across wide European climatic gradients. By regressing principal components analysis of leaf traits [N, P, condensed tannins, lignin, specific leaf area (SLA)] against environmental and soil parameters, we found that: (1) In Q. robur the condensed tannin and lignin contents increased and SLA decreased with precipitation, annual range of temperature, and soil N content, whereas leaf P increased with soil P and temperature; (2) In A. glutinosa leaves N, P, and SLA decreased and condensed tannins increased with temperature, annual range of temperature, and decreasing soil P. On the other hand, leaf P and condensed tannins increased and SLA decreased with minimum annual precipitation and towards sites with low temperature. We selected contrasting leaves in terms of quality to test decomposition and invertebrate consumption. There were intraspecific differences in microbial decomposition rates (field, Q. robur) and consumption by shredders (laboratory, A. glutinosa). We conclude that decomposition rates across ecosystems could be partially governed by climate and soil properties, affecting litter quality and therefore decomposers and detritivores. Under scenarios of global warming and increased nutrients, these results suggest we can expect species-specific changes in leaf-litter properties most likely resulting in slow decomposition with increased variance in temperatures and accelerated decomposition with P increase.

  18. Properties of Chemically Combusted Calcium Carbide Residue and Its Influence on Cement Properties

    Directory of Open Access Journals (Sweden)

    Hongfang Sun

    2015-02-01

    Full Text Available Calcium carbide residue (CCR is a waste by-product from acetylene gas production. The main component of CCR is Ca(OH2, which can react with siliceous materials through pozzolanic reactions, resulting in a product similar to those obtained from the cement hydration process. Thus, it is possible to use CCR as a substitute for Portland cement in concrete. In this research, we synthesized CCR and silica fume through a chemical combustion technique to produce a new reactive cementitious powder (RCP. The properties of paste and mortar in fresh and hardened states (setting time, shrinkage, and compressive strength with 5% cement replacement by RCP were evaluated. The hydration of RCP and OPC (Ordinary Portland Cement pastes was also examined through SEM (scanning electron microscope. Test results showed that in comparison to control OPC mix, the hydration products for the RCP mix took longer to formulate. The initial and final setting times were prolonged, while the drying shrinkage was significantly reduced. The compressive strength at the age of 45 days for RCP mortar mix was found to be higher than that of OPC mortar and OPC mortar with silica fume mix by 10% and 8%, respectively. Therefore, the synthesized RCP was proved to be a sustainable active cementitious powder for the strength enhanced of building materials, which will result in the diversion of significant quantities of this by-product from landfills.

  19. Properties of Chemically Combusted Calcium Carbide Residue and Its Influence on Cement Properties.

    Science.gov (United States)

    Sun, Hongfang; Li, Zishanshan; Bai, Jing; Memon, Shazim Ali; Dong, Biqin; Fang, Yuan; Xu, Weiting; Xing, Feng

    2015-02-13

    Calcium carbide residue (CCR) is a waste by-product from acetylene gas production. The main component of CCR is Ca(OH)₂, which can react with siliceous materials through pozzolanic reactions, resulting in a product similar to those obtained from the cement hydration process. Thus, it is possible to use CCR as a substitute for Portland cement in concrete. In this research, we synthesized CCR and silica fume through a chemical combustion technique to produce a new reactive cementitious powder (RCP). The properties of paste and mortar in fresh and hardened states (setting time, shrinkage, and compressive strength) with 5% cement replacement by RCP were evaluated. The hydration of RCP and OPC (Ordinary Portland Cement) pastes was also examined through SEM (scanning electron microscope). Test results showed that in comparison to control OPC mix, the hydration products for the RCP mix took longer to formulate. The initial and final setting times were prolonged, while the drying shrinkage was significantly reduced. The compressive strength at the age of 45 days for RCP mortar mix was found to be higher than that of OPC mortar and OPC mortar with silica fume mix by 10% and 8%, respectively. Therefore, the synthesized RCP was proved to be a sustainable active cementitious powder for the strength enhanced of building materials, which will result in the diversion of significant quantities of this by-product from landfills.

  20. USE OF SCALED SEMIVARIOGRAMS IN THE PLANNING SAMPLE OF SOIL CHEMICAL PROPERTIES IN SOUTHERN AMAZONAS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Ivanildo Amorim de Oliveira

    2015-02-01

    Full Text Available The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE, forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 × 70 m mesh grids were set up in these areas, with 64 sample points spaced at 10 m distance. Soil samples were collected at the 0.0-0.1 m depth. The chemical properties of pH in water, OM, P, K, Ca, Mg, H+Al, SB, CEC, and V were determined at these points. Data were analyzed by descriptive and geostatistical analyses. A large part of the data analyzed showed spatial dependence. Chemical properties were best fitted to the spherical model in almost all the environments evaluated, except for the sugarcane field with a better fit to the exponential model. ADE and sugarcane areas had greater heterogeneity of soil chemical properties, showing a greater range and higher sampling density; however, forest and agroforestry areas had less variability of chemical properties.

  1. Chemical Composition and Biological Properties of Essential Oils of ...

    African Journals Online (AJOL)

    linoleic acid assays, peppermint oil showed superior antioxidant properties to chocolate mint oil. (4.45 - 19.86 μl/mL). ... hybrid of spearmint (M. spicata L.) and water mint (M. aquatica .... individually to 4.8 mL of the emulsion and this was then ...

  2. THE INFLUENCE OF SOME SOIL CHEMICAL PROPERTIES ON THEIR ERODABILITY

    Directory of Open Access Journals (Sweden)

    I. C. Stanga

    2005-10-01

    Full Text Available Soils from de hills and tableland regions, as well as those from subcarpathian area are characterized through higher erodability. The soils from mountain area present the lowest erodability, especially districambosol, due to the upper horizons properties. The erodabilidydepends on the ratio of historical geological erosion and surface erosion.

  3. Some physico-chemical properties and mineral contents of sweet ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-17

    Jun 17, 2009 ... 8.22, 10.00 and 8.33, respectively. The results of physical properties were fruit mass, 2.76 g; flesh/seed ... plums, apricots, peaches and almonds. Prunus avium L. ..... Oil stability, tocopherol content and some mineral contents.

  4. Topical anti-inflammatory activity of yacon leaf extracts

    Directory of Open Access Journals (Sweden)

    Rejane B. Oliveira

    2013-06-01

    Full Text Available Smallanthus sonchifolius (Poepp. H. Rob. , Asteraceae, known as yacon, is an herb that is traditionally used for the treatment of diabetes in folk medicine. However, recent studies have demonstrated that this plant has other interesting properties such as anti-microbial and anti-inflammatory actions. Thus, the purpose of this study was to evaluate the topical anti-inflammatory property of different extracts prepared from yacon leaves and analyze the role of different chemical classes in this activity. Three yacon leaf extracts were obtained: aqueous extract, where chlorogenic acid derivatives and sesquiterpene lactones were detected; leaf rinse extract, rich in sesquiterpene lactones; and polar extract, rich in chlorogenic acid derivatives. All the extracts exhibited anti-edematogenic activity in vivo (aqueous extract: 25.9% edema inhibition at 0.50 mg/ear; polar extract: 42.7% inhibition at 0.25 mg/ear; and leaf rinse extract: 44.1% inhibition at 0.25 mg/ear. The leaf rinse extract furnished the best results regarding neutrophil migration inhibition, and NO, TNF-α and PGE2 inhibition. These data indicate that both sesquiterpene lactones and chlorogenic acid derivatives contribute to the anti-inflammatory action, although sesquiterpene lactones seem to have more pronounced effects. In conclusion, yacon leaf extracts, particularly the sesquiterpene lactone-rich extract, has potential use as topical anti-inflammatory agent.

  5. Stevia rebaudiana Bertoni - chemical composition and functional properties.

    Science.gov (United States)

    Marcinek, Katarzyna; Krejpcio, Zbigniew

    2015-01-01

    Sweetleaf (Stevia rebaudiana Bertoni), currently investigated by many researchers, has been known and used for more than a thousand years indigenous tribes of South America, who called it "kaa-hee" ("sweet herb"). Thanks to its chemical composition and processability sweetleaf may be an alternative for synthetic sweeteners. Nutritional and health-promoting aspects of Stevia rebaudiana are presently being studied in many research centres. The aim of this study is to present nutritional and health-promoting value of the still-little known sweetleaf.

  6. Stevia rebaudiana Bertoni – chemical composition and functional properties

    Directory of Open Access Journals (Sweden)

    Katarzyna Marcinek

    2015-06-01

    Full Text Available Sweetleaf (Stevia rebaudiana Bertoni, currently investigated by many researchers, has been known and used for more than a thousand years indigenous tribes of South America, who called it “kaa-hee” (“sweet herb”. Thanks to its chemical composition and processability sweetleaf may be an alternative for synthetic sweeteners. Nutritional and health-promoting aspects of Stevia rebaudiana are presently being studied in many research centres. The aim of this study is to present nutritional and health-promoting value of the still-little known sweetleaf.

  7. Diuretic Properties and Chemical Constituent Studies on Stauntonia brachyanthera

    Directory of Open Access Journals (Sweden)

    Xuan Li Liu

    2015-01-01

    Full Text Available The pharmacological evaluation demonstrated that the extracts from the stem of S. brachyanthera could significantly increase the outputs of urine of rats compared to those of furosemide treated group, and the effect could last for a longer period of time. The best effect appeared in the first two hours, which scientifically confirmed the diuretic effect of the plant. The comparative pharmacognosy study showed that the characters of the crude drugs of the stem of S. brachyanthera were similar to those of Akebia caulis. Further systemic work on its chemical constituents by chromatographic methods and NMR elucidations led to the isolation of 10 triterpenoids, 6 flavonoids, 4 lignanoids, and 3 phenylethanoid glycosides, whose structural types were much similar to those of A. quinata. Among them, 7 compounds were firstly reported in the genus of Stauntonia and calceolarioside B was the common characteristic constituent in both plants. From the similar pharmacognosy characters, pharmacological effects, and chemical constituents, it could be concluded that S. brachyanthera have a great possibility to be a succedaneum of Akebia caulis, whose supply is extremely short in recent years.

  8. Quantitative Regression Models for the Prediction of Chemical Properties by an Efficient Workflow.

    Science.gov (United States)

    Yin, Yongmin; Xu, Congying; Gu, Shikai; Li, Weihua; Liu, Guixia; Tang, Yun

    2015-10-01

    Rapid safety assessment is more and more needed for the increasing chemicals both in chemical industries and regulators around the world. The traditional experimental methods couldn't meet the current demand any more. With the development of the information technology and the growth of experimental data, in silico modeling has become a practical and rapid alternative for the assessment of chemical properties, especially for the toxicity prediction of organic chemicals. In this study, a quantitative regression workflow was built by KNIME to predict chemical properties. With this regression workflow, quantitative values of chemical properties can be obtained, which is different from the binary-classification model or multi-classification models that can only give qualitative results. To illustrate the usage of the workflow, two predictive models were constructed based on datasets of Tetrahymena pyriformis toxicity and Aqueous solubility. The qcv (2) and qtest (2) of 5-fold cross validation and external validation for both types of models were greater than 0.7, which implies that our models are robust and reliable, and the workflow is very convenient and efficient in prediction of various chemical properties. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Chemical control of the viscoelastic properties of vinylogous urethane vitrimers

    Science.gov (United States)

    Denissen, Wim; Droesbeke, Martijn; Nicolaÿ, Renaud; Leibler, Ludwik; Winne, Johan M.; Du Prez, Filip E.

    2017-03-01

    Vinylogous urethane based vitrimers are polymer networks that have the intrinsic property to undergo network rearrangements, stress relaxation and viscoelastic flow, mediated by rapid addition/elimination reactions of free chain end amines. Here we show that the covalent exchange kinetics significantly can be influenced by combination with various simple additives. As anticipated, the exchange reactions on network level can be further accelerated using either Brønsted or Lewis acid additives. Remarkably, however, a strong inhibitory effect is observed when a base is added to the polymer matrix. These effects have been mechanistically rationalized, guided by low-molecular weight kinetic model experiments. Thus, vitrimer elastomer materials can be rationally designed to display a wide range of viscoelastic properties.

  10. Chemical and physical properties of bone cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    Po-Liang Lai

    2013-08-01

    Full Text Available Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

  11. Online Data Resources in Chemical Engineering Education: Impact of the Uncertainty Concept for Thermophysical Properties

    Science.gov (United States)

    Kim, Sun Hyung; Kang, Jeong Won; Kroenlein, Kenneth; Magee, Joseph W.; Diky, Vladimir; Muzny, Chris D.; Kazakov, Andrei F.; Chirico, Robert D.; Frenkel, Michael

    2013-01-01

    We review the concept of uncertainty for thermophysical properties and its critical impact for engineering applications in the core courses of chemical engineering education. To facilitate the translation of developments to engineering education, we employ NIST Web Thermo Tables to furnish properties data with their associated expanded…

  12. Online Data Resources in Chemical Engineering Education: Impact of the Uncertainty Concept for Thermophysical Properties

    Science.gov (United States)

    Kim, Sun Hyung; Kang, Jeong Won; Kroenlein, Kenneth; Magee, Joseph W.; Diky, Vladimir; Muzny, Chris D.; Kazakov, Andrei F.; Chirico, Robert D.; Frenkel, Michael

    2013-01-01

    We review the concept of uncertainty for thermophysical properties and its critical impact for engineering applications in the core courses of chemical engineering education. To facilitate the translation of developments to engineering education, we employ NIST Web Thermo Tables to furnish properties data with their associated expanded…

  13. Physical and chemical properties of dust produced in a N2-CH4 RF plasma discharge

    Science.gov (United States)

    Ouni, F.; Adande, G.; Thissen, R.; Alcouffe, G.; Szopa, C.; Schmitz-Afonso, I.; Laprévote, O.; Quirico, E.; Brissaud, O.; Carrasco, N.; Cernogora, G.

    2008-09-01

    Titan's atmospheric chemistry is simulated using a Capacitively Coupled Plasma discharge produced in a N2-CH4 mixture. The produced solid particles are analysed ex-situ. Chemical properties are deduced from: elemental composition, FTIR and LTQ-Orbitrap mass spectrometer. Optical properties are deduced from reflectivity in visible and IR range.

  14. On the physical-chemical properties of ceramide C16

    OpenAIRE

    Souza, Sofia Leite

    2012-01-01

    Dissertation presented to obtain the Ph.D degree in Chemistry. Ceramides are known to be involved in cell signalling and are proposed to assist in the formation of laterally segregated membrane domains, known as ceramide rich domains in cell lipid bilayers. The lipid matrix of the stratum corneum, the uppermost layer of the skin, which is responsible for its water barrier properties, is mainly composed of ceramides, associated with cholesterol, long chain fatty acids and cholesteryl esters...

  15. On the physical-chemical properties of ceramide C16

    OpenAIRE

    Souza, Sofia Leite

    2012-01-01

    Dissertation presented to obtain the Ph.D degree in Chemistry. Ceramides are known to be involved in cell signalling and are proposed to assist in the formation of laterally segregated membrane domains, known as ceramide rich domains in cell lipid bilayers. The lipid matrix of the stratum corneum, the uppermost layer of the skin, which is responsible for its water barrier properties, is mainly composed of ceramides, associated with cholesterol, long chain fatty acids and cholesteryl esters...

  16. Review of Pharmacological Properties and Chemical Constituents of Pimpinella anisum

    OpenAIRE

    2012-01-01

    Pimpinella anisum (anise), belonging to Umbelliferae family, is an aromatic plant which has been used In Iranian traditional medicine (especially its fruits) as carminative, aromatic, disinfectant, and galactagogue. Because the wide traditional usage of Pimpinella anisum for treatment of diseases, in this review published scientific reports about the composition and pharmacological properties of this plant were collected with electronic literature search of GoogleScholar, PubMed, Sciencedirec...

  17. Medicinal Chemical Properties of Successful Central Nervous System Drugs

    OpenAIRE

    Pajouhesh, Hassan; Lenz, George R.

    2005-01-01

    Summary: Fundamental physiochemical features of CNS drugs are related to their ability to penetrate the blood-brain barrier affinity and exhibit CNS activity. Factors relevant to the success of CNS drugs are reviewed. CNS drugs show values of molecular weight, lipophilicity, and hydrogen bond donor and acceptor that in general have a smaller range than general therapeutics. Pharmacokinetic properties can be manipulated by the medicinal chemist to a significant extent. The solubility, permeabi...

  18. MORPHOLOGICAL AND CHEMICAL PROPERTIES OF SELECTED SWEET VIOLET POPULATIONS

    OpenAIRE

    Erhatić, Renata; Vukobratović, Marija; Tomislava PEREMIN VOLF; Vesna ŽIDOVEC

    2010-01-01

    Sweet violet (Viola odorata L.) blooms in continental climate conditions in early spring (March-April) with delicate flowers of attractive scent because of which it is frequently gathered from its natural habitats. Differences among the populations were established according to their morphological properties of twelve populations from Križevci area. Stated information indicates that the populations gathered from meadow – habitat are shorter and have a smaller diameter than the populations gat...

  19. CHEMICAL COMPOSITION AND FUNCTIONAL PROPERTIES OF RICE PROTEIN CONCENTRATES

    Directory of Open Access Journals (Sweden)

    V. V. Kolpakova

    2015-01-01

    Full Text Available Traditionally rice and products of its processing are used to cook porridge, pilaf, lettuce, confectionery, fish, dairy and meat products. At the same time new ways of its processing with releasing of protein products for more effective using, including the use of a glutenfree diet, are developing. The task of this study was a comparative research of nutrition and biological value and functional properties of protein and protein-calcium concentrates produced from rice flour milled from white and brown rice. The traditional and special methods were used. Concentrates were isolated with enzyme preparations of xylanase and amylolytic activity with the next dissolution of protein in diluted hydrochloric acid. Concentrates differed in the content of mineral substances (calcium, zinc, iron and other elements, amino acids and functional properties. The values of the functional properties and indicators of the nutritional value of concentrates from white rice show the advisability of their using in food products, including gluten-free products prepared on the basis of the emulsion and foam systems, and concentrates from brown rice in food products prepared on the basis of using of the emulsion systems. Protein concentrates of brown rice have a low foaming capacity and there is no foam stability at all.

  20. Effects of Hygrothermal Cycling on the Chemical, Thermal, and Mechanical Properties of 862/W Epoxy Resin

    Science.gov (United States)

    Miller, Sandi G.; Roberts, Gary D.; Copa, Christine C.; Bail, Justin L.; Kohlman, Lee W.; Binienda, Wieslaw K.

    2011-01-01

    The hygrothermal aging characteristics of an epoxy resin were characterized over 1 year, which included 908 temperature and humidity cycles. The epoxy resin quickly showed evidence of aging through color change and increased brittleness. The influence of aging on the material s glass transition temperature (Tg) was evaluated by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The Tg remained relatively constant throughout the year long cyclic aging profile. The chemical composition was monitored by Fourier Transform Infrared Spectroscopy (FTIR) where evidence of chemical aging and advancement of cure was noted. The tensile strength of the resin was tested as it aged. This property was severely affected by the aging process in the form of reduced ductility and embrittlement. Detailed chemical evaluation suggests many aging mechanisms are taking place during exposure to hygrothermal conditions. This paper details the influence of processes such as: advancement of cure, chemical degradation, and physical aging on the chemical and physical properties of the epoxy resin.

  1. Structural, chemical and magnetic properties of secondary phases in Co-doped ZnO

    DEFF Research Database (Denmark)

    Ney, A; Kovács, András; Ney, V;

    2011-01-01

    , chemical and magnetic properties of Co-doped ZnO samples. It can be established on a quantitative basis that the superparamagnetic (SPM) behavior observed by integral superconducting quantum interference device magnetometry is not an intrinsic property of the material but stems from precipitations...... of metallic Co. Their presence is revealed by TEM as well as XAS. Annealing procedures for these SPM samples were also studied, and the observed changes in the magnetic properties found to be due to a chemical reduction or oxidation of the metallic Co species....

  2. Dielectric Properties of CDS Nanoparticles Synthesized by Soft Chemical Route

    Indian Academy of Sciences (India)

    R Tripathi; A Kumar; T P Sinha

    2009-06-01

    CdS nanoparticles have been synthesized by a chemical reaction route using thiophenol as a capping agent. The frequency-dependent dielectric dispersion of cadmium sulphide (CdS) is investigated in the temperature range of 303–413 K and in a frequency range of 50 Hz–1 MHz by impedance spectroscopy. An analysis of the complex per-mittivity ( and ) and loss tangent (tan ) with frequency is performed by assuming a distribution of relaxation times. The scaling behaviour of dielectric loss spectra sug- gests that the relaxation describes the same mechanism at various temperatures. The frequency-dependent electrical data are analysed in the framework of conductivity and modulus formalisms. The frequency-dependent conductivity spectra obey the power law.

  3. Effect of prolonged chemical challenges on selected properties of silorane

    DEFF Research Database (Denmark)

    de Jesus, Vivian CBR; Martinelli, Natan Luiz; Pascotto, Renata Corrêa

    Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on water sorption, solubility, and roughness of a silorane-based material when compared to methacrylate-based composites. Methods: Initial roughness and mass were registered for specimens (n=24...... phosphoric acid, 75% ethanol or distilled water for 7, 14, 21, and 180 days, when new measurements were performed. Subsequently, specimens were dehydrated until a constant mass was obtained. Water sorption and solubility were calculated after 180 days of immersion in the different solutions. Data were...... differences in water sorption and solubility were detected amongst the investigated composites (pwater sorption (with similar values to Filtek Z250 and Filtek Z350XT) and low solubility (with similar values to Filtek Z250) after prolonged immersion...

  4. Coffea arabica instant coffee--chemical view and immunomodulating properties.

    Science.gov (United States)

    Capek, Peter; Paulovičová, Ema; Matulová, Mária; Mislovičová, Danica; Navarini, Luciano; Suggi-Liverani, Furio

    2014-03-15

    Results of chemical analyses and immunological studies of two Coffea arabica instant coffee powders obtained by freeze-dried (ICPf) and spray-dried (ICPs) procedures, and arabinogalactan-protein (AGP3) obtained from ICPf are presented. For instant coffee powders no significant differences have been found in carbohydrate (ICPf: 37%, ICPs: 38%) as well as in caffeine (ICPf: 3.0%, ICPs: 3.4%) contents. Their (1)H NMR spectra revealed differences in trigonelline and chlorogenic acids content and in a degree of AGP backbone substitution. Immunobiological tests of all samples (ICPf, ICPs, AGP2 and AGP3) revealed a significant immunostimulatory effect on induction of interleukin 2 and free radicals secretion by mice immunocytes. Moreover, tests revealed more pronounced effect of arabinogalactans AGP2 and AGP3 compared to instant coffee powders (ICPf and ICPs).

  5. EFFECT OF CHEMICAL STRUCTURE OF COMONOMERS ON THE PROPERTIES OF COPOLYESTERS

    Institute of Scientific and Technical Information of China (English)

    WU Rongrui; GAO Jing; LI Huiping

    1997-01-01

    The effect of different kinds of comonomers with or without flexible chain on properties of copolyesters, such as transition temperature, crystallization velocity, crystallinity and size of crystallites, is studied. The experimental results indicate the obvious difference in properties between comonomers with iso- and ortho-structure of phenyl ring and comonomers with flexible chain. The influence of chemical structure of comonomers on properties of copolyesters is discussed.

  6. Synthesis and optoelectronic properties of chemically modified bi-fluorenylidenes

    OpenAIRE

    Wielopolski, Mateusz; Marszalek, Magdalena; Brunetti, Fulvio G.; Joly, Damien; Calbo, Joaquín; Aragó, Juan; Moser, Jacques-E.; Humphry-Baker, Robin; Zakeeruddin, Shaik M.; Delgado, Juan Luis; Grätzel, Michael; Ortí, Enrique; Martín,Nazario

    2016-01-01

    The development of new light harvesting materials is a key issue for the progress of the research on organic & hybrid photovoltaics. Here, we report a new class of organic sensitizers based on the bi-fluorenylidene moiety as p-linker within the donor–p-linker–acceptor (D–p–A) scheme. The new dyes are endowed with electron donor and electron acceptor units at strategic positions in order to improve their electronic and light-harvesting properties. The comprehensive study of these compounds thr...

  7. Intermediate physical chemistry: Stationary properties of chemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Diestler, D.J.; Dence, J.P.

    1987-01-01

    The authors treat the fundamentals of time-independent quantum and statistical mechanics as they apply to problems of interest to chemists. Stresses practical, computational side of physical chemistry rather than the theoretical. Emphasizing computations, it takes the reader step by step through various calculations, including a Hartree-Fock calculation of the ground-state energy of LiH and a calculation of stationary properties of real gases and liquids from virial expansions and distribution functions. Numerical work is intermediate in difficulty. The use of the microcomputer is integrated throughout the text.

  8. Nanoscale chemical interaction enhances the physical properties of bioglass composites.

    Science.gov (United States)

    Ravarian, Roya; Zhong, Xia; Barbeck, Mike; Ghanaati, Shahram; Kirkpatrick, Charles James; Murphy, Ciara M; Schindeler, Aaron; Chrzanowski, Wojciech; Dehghani, Fariba

    2013-10-22

    Bioglasses are favorable biomaterials for bone tissue engineering; however, their applications are limited due to their brittleness. In addition, the early failure in the interface is a common problem of composites of bioglass and a polymer with high mechanical strength. This effect is due to the phase separation, nonhomogeneous mixture, nonuniform mechanical strength, and different degradation properties of two compounds. To address these issues, in this study a nanoscale interaction between poly(methyl methacrylate) (PMMA) and bioactive glass was formed via silane coupling agent (3-trimethoxysilyl)propyl methacrylate (MPMA). A monolith was produced at optimum composition from this hybrid by the sol-gel method at 50 °C with a rapid gelation time (hybrid. The in vivo studies in mice demonstrated that the integrity of the hybrids was maintained in subcutaneous implantation. They induced mainly a mononuclear phagocytic tissue reaction with a low level of inflammation, while bioglass provoked a tissue reaction with TRAP-positive multinucleated giant cells. These results demonstrated that the presence of a nanoscale interaction between bioglass and PMMA affects the properties of bioglass and broadens its potential applications for bone replacement.

  9. Chemical, Mineralogical, and Morphological Properties of Steel Slag

    Directory of Open Access Journals (Sweden)

    Irem Zeynep Yildirim

    2011-01-01

    Full Text Available Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF steelmaking, electric-arc-furnace (EAF steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD analyses and Scanning Electron Microscopy (SEM studies. The XRD patterns of both BOF and EAF(L slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.

  10. A novel property of spider silk: chemical defence against ants.

    Science.gov (United States)

    Zhang, Shichang; Koh, Teck Hui; Seah, Wee Khee; Lai, Yee Hing; Elgar, Mark A; Li, Daiqin

    2012-05-07

    Spider webs are made of silk, the properties of which ensure remarkable efficiency at capturing prey. However, remaining on, or near, the web exposes the resident spiders to many potential predators, such as ants. Surprisingly, ants are rarely reported foraging on the webs of orb-weaving spiders, despite the formidable capacity of ants to subdue prey and repel enemies, the diversity and abundance of orb-web spiders, and the nutritional value of the web and resident spider. We explain this paradox by reporting a novel property of the silk produced by the orb-web spider Nephila antipodiana (Walckenaer). These spiders deposit on the silk a pyrrolidine alkaloid (2-pyrrolidinone) that provides protection from ant invasion. Furthermore, the ontogenetic change in the production of 2-pyrrolidinone suggests that this compound represents an adaptive response to the threat of natural enemies, rather than a simple by-product of silk synthesis: while 2-pyrrolidinone occurs on the silk threads produced by adult and large juvenile spiders, it is absent on threads produced by small juvenile spiders, whose threads are sufficiently thin to be inaccessible to ants.

  11. Controlling Properties and Cytotoxicity of Chitosan Nanocapsules by Chemical Grafting

    Directory of Open Access Journals (Sweden)

    Laura De Matteis

    2016-09-01

    Full Text Available The tunability of the properties of chitosan-based carriers opens new ways for the application of drugs with low water-stability or high adverse effects. In this work, the combination of a nanoemulsion with a chitosan hydrogel coating and the following poly (ethylene glycol (PEG grafting is proven to be a promising strategy to obtain a flexible and versatile nanocarrier with an improved stability. Thanks to chitosan amino groups, a new easy and reproducible method to obtain nanocapsule grafting with PEG has been developed in this work, allowing a very good control and tunability of the properties of nanocapsule surface. Two different PEG densities of coverage are studied and the nanocapsule systems obtained are characterized at all steps of the optimization in terms of diameter, Z potential and surface charge (amino group analysis. Results obtained are compatible with a conformation of PEG molecules laying adsorbed on nanoparticle surface after covalent linking through their amino terminal moiety. An improvement in nanocapsule stability in physiological medium is observed with the highest PEG coverage density obtained. Cytotoxicity tests also demonstrate that grafting with PEG is an effective strategy to modulate the cytotoxicity of developed nanocapsules. Such results indicate the suitability of chitosan as protective coating for future studies oriented toward drug delivery.

  12. Controlling Properties and Cytotoxicity of Chitosan Nanocapsules by Chemical Grafting

    Science.gov (United States)

    De Matteis, Laura; Alleva, Maria; Serrano-Sevilla, Inés; García-Embid, Sonia; Stepien, Grazyna; Moros, María; de la Fuente, Jesús M.

    2016-01-01

    The tunability of the properties of chitosan-based carriers opens new ways for the application of drugs with low water-stability or high adverse effects. In this work, the combination of a nanoemulsion with a chitosan hydrogel coating and the following poly (ethylene glycol) (PEG) grafting is proven to be a promising strategy to obtain a flexible and versatile nanocarrier with an improved stability. Thanks to chitosan amino groups, a new easy and reproducible method to obtain nanocapsule grafting with PEG has been developed in this work, allowing a very good control and tunability of the properties of nanocapsule surface. Two different PEG densities of coverage are studied and the nanocapsule systems obtained are characterized at all steps of the optimization in terms of diameter, Z potential and surface charge (amino group analysis). Results obtained are compatible with a conformation of PEG molecules laying adsorbed on nanoparticle surface after covalent linking through their amino terminal moiety. An improvement in nanocapsule stability in physiological medium is observed with the highest PEG coverage density obtained. Cytotoxicity tests also demonstrate that grafting with PEG is an effective strategy to modulate the cytotoxicity of developed nanocapsules. Such results indicate the suitability of chitosan as protective coating for future studies oriented toward drug delivery. PMID:27706041

  13. Review of Pharmacological Properties and Chemical Constituents of Pimpinella anisum.

    Science.gov (United States)

    Shojaii, Asie; Abdollahi Fard, Mehri

    2012-01-01

    Pimpinella anisum (anise), belonging to Umbelliferae family, is an aromatic plant which has been used In Iranian traditional medicine (especially its fruits) as carminative, aromatic, disinfectant, and galactagogue. Because the wide traditional usage of Pimpinella anisum for treatment of diseases, in this review published scientific reports about the composition and pharmacological properties of this plant were collected with electronic literature search of GoogleScholar, PubMed, Sciencedirect, Scopus, and SID from 1970 to 2011. So far, different studies were performed on aniseeds and various properties such as antimicrobial, antifungal, antiviral, antioxidant, muscle relaxant, analgesic and anticonvulsant activity as well as different effects on gastrointestinal system have been reported of aniseeds. It can also reduce morphine dependence and has beneficial effects on dysmenorrhea and menopausal hot flashes in women. In diabetic patients, aniseeds showed hypoglycemic and hypolipidemic effect and reduce lipid peroxidation. The most important compounds of aniseeds essential oil were trans-anetole, estragole, γ-hymachalen, para-anisaldehyde and methyl cavicol. Due to broad spectrum of pharmacological effects, and very few clinical studies of Pimpinella anisum, more clinical trials are recommended to evaluate the beneficial effects of this plant in human models and synthesis of new drugs from the active ingredients of this plant in future.

  14. The effects of leaf roughness, surface free energy and work of adhesion on leaf water drop adhesion.

    Directory of Open Access Journals (Sweden)

    Huixia Wang

    Full Text Available The adhesion of water droplets to leaves is important in controlling rainfall interception, and affects a variety of hydrological processes. Leaf water drop adhesion (hereinafter, adhesion depends not only on droplet formulation and parameters but also on the physical (leaf roughness and physico-chemical (surface free energy, its components, and work-of-adhesion properties of the leaf surface. We selected 60 plant species from Shaanxi Province, NW China, as experimental materials with the goal of gaining insight into leaf physical and physico-chemical properties in relation to the adhesion of water droplets on leaves. Adhesion covered a wide range of area, from 4.09 to 88.87 g/m(2 on adaxial surfaces and 0.72 to 93.35 g/m(2 on abaxial surfaces. Distinct patterns of adhesion were observed among species, between adaxial and abaxial surfaces, and between leaves with wax films and wax crystals. Adhesion decreased as leaf roughness increased (r =  -0.615, p = 0.000, but there were some outliers, such as Salix psammophila and Populus simonii with low roughness and low adhesion, and the abaxial surface of Hyoscyamus pusillus and the adaxial surface of Vitex negundo with high roughness and high adhesion. Meanwhile, adhesion was positively correlated with surface free energy (r = 0.535, p = 0.000, its dispersive component (r = 0.526, p = 0.000, and work of adhesion for water (r = 0.698, p = 0.000. However, a significant power correlation was observed between adhesion and the polar component of surface free energy (p = 0.000. These results indicated that leaf roughness, surface free energy, its components, and work-of-adhesion for water played important roles in hydrological characteristics, especially work-of-adhesion for water.

  15. Exploring experimental fitness landscapes for chemical synthesis and property optimization.

    Science.gov (United States)

    Tibbetts, Katharine Moore; Feng, Xiao-Jiang; Rabitz, Herschel

    2017-02-08

    Optimization is a central goal in the chemical sciences, encompassing diverse objectives including synthesis yield, catalytic activity of a material, and binding efficiency of a molecule to a target protein. Considering the enormous size of chemical space and the expected large numbers of experiments necessary to search through it in any particular application, optimization in chemistry is surprisingly efficient. This good fortune has recently been explained by analysis of the fitness landscape, i.e., the functional relationship between a target objective J (e.g., percent yield, catalytic activity) and a suitable set of variables (e.g., resources such as reactant concentrations and processing conditions). Mathematical analysis has demonstrated that, upon satisfaction of reasonable physical assumptions, the fitness landscape contains no local sub-optimal "traps" that preclude identification of the globally best value of J, in a development called the "OptiChem" theorem. One of the key assumptions behind the theorem is that sufficient resources are available to achieve the posed optimization goal. This work assesses the validity of this assumption underlying the OptiChem theorem through examination of experimental data from the recent literature. In order to explore fitness landscapes in high dimensions where the landscape cannot be visualized, a high dimensional model representation (HDMR) of experimental data is used to construct a model landscape amenable to topology assessment via gradient algorithm search. This method is shown to correctly capture the trap-free topology of a four-dimensional landscape where the objective is to optimize the composition of a solid state material (subject to an elemental mole-fraction constraint) for catalytic activity towards the oxygen evolution reaction. Analysis of a six-dimensional landscape for the objective of maximizing the photoluminescence of rare-earth solid state materials subject to two elemental mole

  16. Investigation of the redox property of a metalloprotein layer self-assembled on various chemical linkers.

    Science.gov (United States)

    Chung, Yong-Ho; Lee, Taek; Min, Junhong; Choi, Jeong-Woo

    2011-10-01

    Myogloblin, a well-known metalloprotein, was immobilized on a gold surface using various chemical linkers to investigate the length effect of chemical linker on the electron transfer in protein layers, because chemical linkers play roles in the pathway that transfers the electron from the protein to the gold substrate and act as protein immobilization reagents. Chemical linkers with 2, 6, 11, and 16 carbons were utilized to confirm length-effects. The immobilization of protein and chemical linker was validated with surface plasmon resonance (SPR) and atomic force microscopy (AFM). The electrochemical property was evaluated by cyclic voltammetry (CV) and chronocoulometry (CC). In those results, redox peaks of immobilized protein were controlled via the length of chemical linkers, and it could be directly applied to the realization of bioelectronic device.

  17. Physico-chemical and technological properties of ceramic tiles: Role of clay minerals on as pressed and dried compacts properties

    Directory of Open Access Journals (Sweden)

    Gouzouli N.

    2013-09-01

    Full Text Available Chemical, mineralogical and technological properties of an experimental clay are investigated with the aim to substitute for other clays used at present in factories. Flexural strength distributions of green and dry compacts were analysed and correlated to microstructural features with a view to evaluate their drying ability and their mechanical reliability.

  18. Antioxidant and non-toxic properties of Piper betle leaf extract: in vitro and in vivo studies.

    Science.gov (United States)

    Choudhary, Dharamainder; Kale, Raosaheb K

    2002-08-01

    Piper betle leaves are used in folk medicine for the treatment of various disorders and is commonly chewed among Asians. The present study investigates the protective efficacy of P. betle leaf extract. The presence of the extract inhibited the radiation induced lipid peroxidation process effectively. This could be attributed to its ability to scavenge free radicals involved in initiation and propagation steps. Oral supplementation with extract (1, 5 and 10 mg/kg) was administered daily for 2 weeks to Swiss albino mice and the hepatic antioxidant status was analysed. The GSH content was enhanced and no appreciable change was found in the levels of oxidative damage in terms of lipid peroxidation. Also, the specific activity of SOD increased in a dose dependent manner. These factors indicate the elevation of antioxidant status in the animals. The effect on the glyoxalase system which is considered to be activated under stress conditions was also investigated. Our findings did not observe any significant change in gly I and gly II activities, implying a non-stress condition after oral treatment of the extract. The present study indicates the antioxidant activity of P. betle leaf extract and its potential to elevate the antioxidant status.

  19. Examination of lignocellulosic fibers for chemical, thermal, and separations properties: Addressing thermo-chemical stability issues

    Science.gov (United States)

    Johnson, Carter David

    Natural fiber-plastic composites incorporate thermoplastic resins with fibrous plant-based materials, sometimes referred to as biomass. Pine wood mill waste has been the traditional source of natural fibrous feedstock. In anticipation of a waste wood shortage other fibrous biomass materials are being investigated as potential supplements or replacements. Perennial grasses, agricultural wastes, and woody biomass are among the potential source materials. As these feedstocks share the basic chemical building blocks; cellulose, hemicellulose, and lignin, they are collectively called lignocellulosics. Initial investigation of a number of lignocellulosic materials, applied to fiber-plastic composite processing and material testing, resulted in varied results, particularly response to processing conditions. Less thermally stable lignocellulosic filler materials were physically changed in observable ways: darkened color and odor. The effect of biomass materials' chemical composition on thermal stability was investigated an experiment involving determination of the chemical composition of seven lignocellulosics: corn hull, corn stover, fescue, pine, soy hull, soy stover, and switchgrass. These materials were also evaluated for thermal stability by thermogravimetric analysis. The results of these determinations indicated that both chemical composition and pretreatment of lignocellulosic materials can have an effect on their thermal stability. A second study was performed to investigate what effect different pretreatment systems have on hybrid poplar, pine, and switchgrass. These materials were treated with hot water, ethanol, and a 2:1 benzene/ethanol mixture for extraction times of: 1, 3, 6, 12, and 24 hours. This factorial experiment demonstrated that both extraction time and medium have an effect on the weight percent of extractives removed from all three material types. The extracted materials generated in the above study were then subjected to an evaluation of thermal

  20. Quantum chemical studies of photochromic properties of benzoxazine compound

    Energy Technology Data Exchange (ETDEWEB)

    Toliautas, Stepas, E-mail: stepas.toliautas@ff.stud.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Sulskus, Juozas, E-mail: juozas.sulskus@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Valkunas, Leonas, E-mail: leonas.valkunas@ff.vu.lt [Department of Theoretical Physics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania); Institute of Physics, Center for Physical Sciences and Technology, Savanoriu 231, LT-02300 Vilnius (Lithuania); Vengris, Mikas, E-mail: mikas.vengris@ff.vu.lt [Department of Quantum Electronics, Vilnius University, Sauletekio 9-III, LT-10222 Vilnius (Lithuania)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Photochromic indolo-benzoxazine compound is studied. Black-Right-Pointing-Pointer Advanced LC-TDDFT and GMC-QDPT methods are used for excited state calculations. Black-Right-Pointing-Pointer Oxazine ring opens upon UV light excitation. Black-Right-Pointing-Pointer Fragments of the compound assume structures similar to the ions of separate molecules. Black-Right-Pointing-Pointer Multiple pathways of the photo-induced reaction are expected. -- Abstract: Molecular electronic structure of ground and excited states of a photochromic indolo[2,1-b][1,3]benzoxazine compound incorporating closed-ring system, which opens upon UV light excitation, was studied using various quantum chemical methods. Three local minima of the ground electronic state potential energy surface and related transition states were identified along the path of rotation of 4-nitrophenol group. Additionally, three local minima of the excited electronic states were located. The evaluated transition energy barriers between local ground-state minima nearest to the initial structure of the investigated molecule are less than 2 k{sub B}T, making open structures likely to revert to the initial structure by thermalization. Results obtained using ab initio GMC-QDPT method were explored and compared to the widely used TD-DFT and semi-empiric ZINDO methods.

  1. Chemical Precipitation Synthesis and Thermoelectric Properties of Copper Sulfide

    Science.gov (United States)

    Wu, Sixin; Jiang, Jing; Liang, Yinglin; Yang, Ping; Niu, Yi; Chen, Yide; Xia, Junfeng; Wang, Chao

    2017-04-01

    Earth-abundant copper sulfide compounds have been intensively studied as potential thermoelectric materials due to their high dimensionless figure of merit ZT values. They have a unique phonon-liquid electron-crystal model that helps to achieve high thermoelectric performance. Many methods, such as melting and ball-milling, have been adopted to synthesize this copper sulfide compound, but they both use expensive starting materials with high purity. Here, we develop a simple chemical precipitation approach to synthesize copper sulfide materials through low-cost analytically pure compounds as the starting materials. A high ZT value of 0.93 at 800 K was obtained from the samples annealed at 1273 K. Its power factor is around 8.0 μW cm-1 K-2 that is comparable to the highest record reported by traditional methods. But, the synthesis here has been greatly simplified with reduced cost, which will be of great benefit to the potential mass production of thermoelectric devices. Furthermore, this method can be applied to the synthesis of other sulfur compound thermoelectric materials.

  2. Effect of prolonged chemical challenges on selected properties of silorane

    DEFF Research Database (Denmark)

    de Jesus, Vivian CBR; Martinelli, Natan Luiz; Pascotto, Renata Corrêa;

    Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on water sorption, solubility, and roughness of a silorane-based material when compared to methacrylate-based composites. Methods: Initial roughness and mass were registered for specimens (n=24......) fabricated from methacrylate (Filtek Z250, 3M ESPE; Filtek Z350XT, 3M ESPE; Master Fill, Biodinâmica) or silorane-based (Filtek P90, 3M ESPE) composites. The volume of all specimens was also calculated. Specimens were divided in four groups (n=6) and individually stored at 37°C in 0.02N citric acid, 0.02N...... submitted to two-way analysis of variance or analysis of variance for repeated measures, and Tukey’s multiple comparison test (a=0.05). Results: The silorane-based composite was the roughest (pcomposite (Ra=0.06±0.01) when compared to the other investigated materials (Ra=0.05±0.01). Significant...

  3. Chemical composition and antigenotoxic properties of Lippia alba essential oils

    Directory of Open Access Journals (Sweden)

    Molkary Andrea López

    2011-01-01

    Full Text Available The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS analysis. The major compounds encountered being citral (33% geranial and 25% neral, geraniol (7% and trans-β-caryophyllene (7% for L. alba specimen COL512077, and carvone (38%, limonene (33% and bicyclosesquiphellandrene (8% for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds.

  4. Prediction of Wine Sensorial Quality by Routinely Measured Chemical Properties

    Directory of Open Access Journals (Sweden)

    Bednárová Adriána

    2014-12-01

    Full Text Available The determination of the sensorial quality of wines is of great interest for wine consumers and producers since it declares the quality in most of the cases. The sensorial assays carried out by a group of experts are time-consuming and expensive especially when dealing with large batches of wines. Therefore, an attempt was made to assess the possibility of estimating the wine sensorial quality with using routinely measured chemical descriptors as predictors. For this purpose, 131 Slovenian red wine samples of different varieties and years of production were analysed and correlation and principal component analysis were applied to find inter-relations between the studied oenological descriptors. The method of artificial neural networks (ANNs was utilised as the prediction tool for estimating overall sensorial quality of red wines. Each model was rigorously validated and sensitivity analysis was applied as a method for selecting the most important predictors. Consequently, acceptable results were obtained, when data representing only one year of production were included in the analysis. In this case, the coefficient of determination (R2 associated with training data was 0.95 and that for validation data was 0.90. When estimating sensorial quality in categorical form, 94 % and 85 % of correctly classified samples were achieved for training and validation subset, respectively.

  5. Chemical composition and antigenotoxic properties of Lippia alba essential oils.

    Science.gov (United States)

    López, Molkary Andrea; Stashenko, Elena E; Fuentes, Jorge Luis

    2011-07-01

    The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds.

  6. Efficient Way to Improve Subgrade Property of Pavement by Chemical Stabilization

    Directory of Open Access Journals (Sweden)

    Rajshekhar G Rathod

    2017-01-01

    Full Text Available There are numerous soil stabilization techniques for improving the strength of the in-situ soil especially in road construction, and one of the techniques is using chemical additive. Chemical improvement is a time saving method that enables subgrade or sub-base layer and otherwise unsatisfactory materials in-situ to obtain higher density and strength, obviating the need for costly excavation and replacement with borrow material. This paper presents some results of the preliminary stages of research program carried out to explicate the mechanism and behavior between the liquid chemical and the engineering properties of three natural residual soils at laboratory scale. Liquid-formed chemical was selected in this research due to scarcity of such findings instead of the prevalent solid chemical additive such as lime, cement or fly ash. The focus on this research is on the improvement of engineering properties of two natural residual soils and mixed with different proportions of liquid chemical. Series of laboratory test on engineering properties, such as Modified Proctor Test, Consistency limits, moisture-density relationship (compaction and California Bearing Ratio was undertaken to evaluate the effectiveness and performances of this chemical as soil stabilizing agent.

  7. Biomechanical properties of acellular sciatic nerves treated with a modified chemical method

    Institute of Scientific and Technical Information of China (English)

    Xinlong Ma; Zhao Yang; Xiaolei Sun; Jianxiong Ma; Xiulan Li; Zhenzhen Yuan; Yang Zhang; Honggang Guo

    2011-01-01

    Nerve grafts are able to adapt to surrounding biomechanical environments if the nerve graft itself exhibits appropriate biomechanical properties (load, elastic modulus, etc.). The present study was designed to determine the differences in biomechanical properties between fresh and chemically acellularized sciatic nerve grafts. Two different chemical methods were used to establish acellular nerve grafts. The nerve was chemically extracted in the Sondell method with a combination of Triton X-100 (nonionic detergent) and sodium deoxycholate (anionic detergent), and in the modified method with a combination of Triton X-200 (anionic detergent), sulfobetaine-10 (SB-10, amphoteric detergents), and sulfobetaine-16 (SB-16, amphoteric detergents). Following acellularization, hematoxylin-eosin staining and scanning electron microscopy demonstrated that the effect of acellularization via the modified method was similar to the traditional Sondell method. However, effects of demyelination and nerve fiber tube integrity were superior to the traditional Sondell method. Biomechanical testing showed that peripheral nerve graft treated using the chemical method resulted in decreased biomechanical properties (ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture) compared with fresh nerves, but the differences had no statistical significance (P > 0.05). These results demonstrated no significant effect on biomechanical properties of nerves treated using the chemical method. In conclusion, nerve grafts treated via the modified method removed Schwann cells, preserved neural structures, and ensured biomechanical properties of the nerve graft, which could be more appropriate for implantation studies.

  8. Physical and chemical properties of substrates produced using macrophytes aquatics

    Directory of Open Access Journals (Sweden)

    Walda Monteiro Farias

    2013-12-01

    Full Text Available Aquatic macrophytes are widely used as bioindicators of water quality because their proliferation usually occurs in eutrophic water sources and has hit several parts of Brazil and the world, restricted the multiple uses of aquatic ecosystems. However, this group of plants is able to retain considerable amounts of nutrients, presenting high productivity and high growth rate, thus, a good source of biomass for use in the production of substrates. In order to evaluate the potential of aquatic macrophytes water hyacinth (Eichhornia crassipes Solms., water lettuce (Pistia stratiotes L. and cattail (Typha domingensis Pers. in the production of substrates was performed in this work, the physical and chemical characterization and evaluation of the degree of humification. The treatments were arranged in a 3 × 4 factorial, completely randomized design with three replications. All substrates produced with 100% macrophyte density present within the limits of 400 kg m-3, considered ideal. The composite substrates with water hyacinth and water lettuce are with the electrical conductivity of 0,79 a 2,49 dS m-1 within recommended. organic compounds produced are considered mature and have high levels of nitrogen phosphorus and potassium; The substrate produced with 70% water lettuce +30 % dung and 70% composed of cattail manure +20% +10% topsoil and 70 +30% cattail manure have C/N ratio within the considered ideal; the humification ratio and humification index, except for the four treatments (70 % water lettuce manure +30%, 5 (100% water hyacinth and 8 (70% water hyacinth manure +30% are within the considered ideal, the percentage of humic acids and polymerization rate, except for treatments 1 (100% water lettuce and 12 (100% cattail, are shown below the ideal.

  9. Chemical Properties And Toxicity of Chromium(III) Nutritional Supplements

    Energy Technology Data Exchange (ETDEWEB)

    Levina, A.; Lay, P.A.

    2009-05-19

    The status of Cr(III) as an essential micronutrient for humans is currently under question. No functional Cr(III)-containing biomolecules have been definitively described as yet, and accumulated experience in the use of Cr(III) nutritional supplements (such as [Cr(pic){sub 3}], where pic = 2-pyridinecarboxylato) has shown no measurable benefits for nondiabetic people. Although the use of large doses of Cr(III) supplements may lead to improvements in glucose metabolism for type 2 diabetics, there is a growing concern over the possible genotoxicity of these compounds, particularly of [Cr(pic){sub 3}]. The current perspective discusses chemical transformations of Cr(III) nutritional supplements in biological media, with implications for both beneficial and toxic actions of Cr(III) complexes, which are likely to arise from the same biochemical mechanisms, dependent on concentrations of the reactive species. These species include: (1) partial hydrolysis products of Cr(III) nutritional supplements, which are capable of binding to biological macromolecules and altering their functions; and (2) highly reactive Cr(VI/V/IV) species and organic radicals, formed in reactions of Cr(III) with biological oxidants. Low concentrations of these species are likely to cause alterations in cell signaling (including enhancement of insulin signaling) through interactions with the active centers of regulatory enzymes in the cell membrane or in the cytoplasm, while higher concentrations are likely to produce genotoxic DNA lesions in the cell nucleus. These data suggest that the potential for genotoxic side-effects of Cr(III) complexes may outweigh their possible benefits as insulin enhancers, and that recommendations for their use as either nutritional supplements or antidiabetic drugs need to be reconsidered in light of these recent findings.

  10. Chemical properties and toxicity of soils contaminated by mining activity.

    Science.gov (United States)

    Agnieszka, Baran; Tomasz, Czech; Jerzy, Wieczorek

    2014-09-01

    This research is aimed at assessing the total content and soluble forms of metals (zinc, lead and cadmium) and toxicity of soils subjected to strong human pressure associated with mining of zinc and lead ores. The research area lay in the neighbourhood of the Bolesław Mine and Metallurgical Plant in Bukowno (Poland). The study obtained total cadmium concentration between 0.29 and 51.91 mg, zinc between 7.90 and 3,614 mg, and that of lead between 28.4 and 6844 mg kg(-1) of soil d.m. The solubility of the heavy metals in 1 mol dm(-3) NH4NO3 was 1-49% for zinc, 5-45% for cadmium, and Toxicity assessment of the soil samples was performed using two tests, Phytotoxkit and Microtox(®). Germination index values were between 22 and 75% for Sinapis alba, between 28 and 100% for Lepidium sativum, and between 10 and 28% for Sorghum saccharatum. Depending on the studied soil sample, Vibrio fischeri luminescence inhibition was 20-96%. The sensitivity of the test organisms formed the following series: S. saccharatum > S. alba = V. fischeri > L. sativum. Significant positive correlations (p ≤ 0.05) of the total and soluble contents of the metals with luminescence inhibition in V. fischeri and root growth inhibition in S. saccharatum were found. The general trend observed was an increase in metal toxicity measured by the biotest with increasing available metal contents in soils. All the soil samples were classified into toxicity class III, which means that they are toxic and present severe danger. Biotest are a good complement to chemical analyses in the assessment of quality of soils as well as in properly managing them.

  11. Optimization of the sampling scheme for maps of physical and chemical properties estimated by kriging

    Directory of Open Access Journals (Sweden)

    Gener Tadeu Pereira

    2013-10-01

    Full Text Available The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial Simulated Annealing (SSA method were used to minimize kriging variance. The optimization procedure was validated by constructing maps of relative improvement comparing the sample configuration before and after the process. A greater concentration of recommended points in specific areas (NW-SE direction was observed, which also reflects a greater estimate variance at these locations. The addition of optimal samples, for specific regions, increased the accuracy up to 2 % for chemical and 1 % for physical properties. The use of a sample grid and medium-scale variogram, as previous information for the conception of additional sampling schemes, was very promising to determine the locations of these additional points for all physical and chemical soil properties, enhancing the accuracy of kriging estimates of the physical-chemical properties.

  12. Chemical composition and antifungal properties of essential oils of three Pistacia species.

    Science.gov (United States)

    Duru, M E; Cakir, A; Kordali, S; Zengin, H; Harmandar, M; Izumi, S; Hirata, T

    2003-02-01

    The chemical composition of essential oils obtained from the leaves of Pistacia vera, Pistacia terebinthus, Pistacia lentiscus and the resin of Pistacia lentiscus were analyzed by GC and GC-MS. alpha-Pinene, beta-pinene, limonene, terpinen-4-ol and alpha-terpineol were found to be the major components. The antifungal activities of the above oils and P. lentiscus resin (total, acidic and neutral fractions) against the growth of three agricultural pathogens, Pythium ultimum, Rhizoctonia solani and Fusarium sambucinum were evaluated. Some doses of P. terebinthus, P. vera and P. lentiscus leaf oils and total and neutral fraction of P. lentiscus resin significantly inhibited the growth of R. solani. However, all samples did not show antifungal activity against P. ultimum and F. sambucinum, but increased the growth of F. sambucinum.

  13. Microscopic physical and chemical properties of graphite intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, P.C.

    1992-08-24

    Optical spectroscopy (Raman, FTIR and Reflection ) was used to study a variety of acceptor- and donor-type compounds synthesized to determine the microscopic models consistent with the spectrocsopic results. General finding is that the electrical conduction properties of these compounds can be understood on the basis that the intercalation of atomic and/or molecular species between the host graphite layers either raises or lowers the Fermi level (E{sub F)} in a graphitic band structure. This movement of E{sub F} is accomplished via a charge transfer of electrons from the intercalate layers to the graphitic layers (donor compounds), or vice versa (acceptor compounds). Furthermore, the band structure must be modified to take into account the layers of charge that occur as a result of the charge transfer. This charge layering introduces additional bands of states near E{sub F}, which are discussed. Charge-transfer also induces a perturbation of the graphitic normal mode frequencies which can be understood as the result of a contraction (acceptor compounds) or expansion (donor compounds) of the intralayer C-C bonds. Ab-initio calculations support this view and are in reasonable agreement with experimental data.

  14. Callus cell proliferation from broccoli leaf slice using IBA and BAP in vitro culture: Its biochemical and antioxidant properties

    Directory of Open Access Journals (Sweden)

    A.B.M. Sharif Hossain

    2016-03-01

    Full Text Available Plant tissue or cell culture keeps a significant role in micro-propagation in the plant production industry. Combination of 6-Benzylaminopurine (BAP and other plant growth regulators like 1-Naphthaleneacetic acid (NAA or Indole-3-acetic acid (IAA or indole-3-butyric acid (IBA was used in the most of the research in tissue culture. The study was carried out to investigate the optimization of the concentration of IBA and BAP combination (0, 0.25, 0.50, 1.0, 1.50, 2.0, 2.5, 3.0 and 3.5 mg/l for the root, callus and leaf proliferation from the leaf cutting slice. The highest number (6.75 of root proliferation was observed in the concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination. The callus initiation was found in the concentration of IBA 1.0–3.5 mg/l+BAP 1.0–2.0 mg/l. However, the highest callus weight was observed at the concentration of IBA 1.5 mg/l+BAP 1.0 mg/l combination than other combination of concentrations. Positively leaf initiation and formation was better in the concentration of IBA 1–3.5 mg/l+BAP 1.0–2.0 mg/l combination. In addition, the 2,2-diphenyl-2-picrylhydarzyl (DPPH free radical scavenging potential was higher (70.1% in leaves extract than in callus extracts (46.3% at the concentration of 10 mg/ml though both extracts had lower DPPH free radical scavenging activity compared to the positive control, vitamin C and BHT. Theresults conclude that the optimum concentration was IBA 1.5 mg/l+BAP 1.0 mg/l combination to produce callus cell proliferation and concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination was the optimum for root proliferation of broccoli in vitro.

  15. Callus cell proliferation from broccoli leaf slice using IBA and BAP in vitro culture: Its biochemical and antioxidant properties.

    Science.gov (United States)

    Sharif Hossain, A B M; Haq, Imdadul; Ibrahim, Nasir A; Aleissa, Mohammed Saad

    2016-03-01

    Plant tissue or cell culture keeps a significant role in micro-propagation in the plant production industry. Combination of 6-Benzylaminopurine (BAP) and other plant growth regulators like 1-Naphthaleneacetic acid (NAA) or Indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA) was used in the most of the research in tissue culture. The study was carried out to investigate the optimization of the concentration of IBA and BAP combination (0, 0.25, 0.50, 1.0, 1.50, 2.0, 2.5, 3.0 and 3.5 mg/l) for the root, callus and leaf proliferation from the leaf cutting slice. The highest number (6.75) of root proliferation was observed in the concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination. The callus initiation was found in the concentration of IBA 1.0-3.5 mg/l+BAP 1.0-2.0 mg/l. However, the highest callus weight was observed at the concentration of IBA 1.5 mg/l+BAP 1.0 mg/l combination than other combination of concentrations. Positively leaf initiation and formation was better in the concentration of IBA 1-3.5 mg/l+BAP 1.0-2.0 mg/l combination. In addition, the 2,2-diphenyl-2-picrylhydarzyl (DPPH) free radical scavenging potential was higher (70.1%) in leaves extract than in callus extracts (46.3%) at the concentration of 10 mg/ml though both extracts had lower DPPH free radical scavenging activity compared to the positive control, vitamin C and BHT. Theresults conclude that the optimum concentration was IBA 1.5 mg/l+BAP 1.0 mg/l combination to produce callus cell proliferation and concentration of 2.0 mg/l IBA+0.25 mg/l BAP combination was the optimum for root proliferation of broccoli in vitro.

  16. Spatially resolved physical and chemical properties of the planetary nebula NGC 3242

    CERN Document Server

    Monteiro, H; Leal-Ferreira, M L; Corradi, R L M

    2013-01-01

    Optical integral-field spectroscopy was used to investigate the planetary nebula NGC 3242. We analysed the main morphological components of this source, including its knots, but not the halo. In addition to revealing the properties ofthe physical and chemical nature of this nebula, we also provided reliable spatially resolved constraints that can be used for future photoionisation modelling of the nebula. The latter is ultimately necessary to obtain a fully self-consistent 3D picture of the physical and chemical properties of the object. The observations were obtained with the VIMOS instrument attached to VLT-UT3. Maps and values for specific morphological zones for the detected emission-lines were obtained and analysed with routines developed by the authors to derive physical and chemical conditions of the ionised gas in a 2D fashion. We obtained spatially resolved maps and mean values of the electron densities, temperatures, and chemical abundances, for specific morphological structures in NGC~3242. These r...

  17. Modification of optical and electrical properties of chemical bath deposited CdS using plasma treatments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G. Alan; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2011-08-31

    Cadmium sulphide (CdS) is a well known n-type semiconductor that is widely used in solar cells. Here we report preparation and characterization of chemical bath deposited CdS thin films and modification of their optical and electrical properties using plasma treatments. CdS thin films were prepared from a chemical bath containing Cadmium chloride, Triethanolamine and Thiourea under various deposition conditions. Good quality thin films were obtained during deposition times of 5, 10 and 15 min. CdS thin films prepared for 10 min. were treated using a glow discharge plasma having nitrogen and argon carrier gases. The changes in morphology, optical and electrical properties of these plasma treated CdS thin films were analyzed in detail. The results obtained show that plasma treatment is an effective technique in modification of the optical and electrical properties of chemical bath deposited CdS thin films.

  18. [Relationship among soil enzyme activities, vegetation state, and soil chemical properties of coal cinder yard].

    Science.gov (United States)

    Wang, Youbao; Zhang, Li; Liu, Dengyi

    2003-01-01

    From field investigation and laboratory analysis, the relationships among soil enzyme activities, vegetation state and soil chemical properties of coal cinder yard in thermal power station were studied. The results showed that vegetation on coal cinder yard was distributed in scattered patch mainly with single species of plant, and herbs were the dominant species. At the same time, the activity of three soil enzymes had a stronger relativity to environment conditions, such as vegetation state and soil chemical properties. The sensitivity of three soil enzymes to environmental stress was in order of urease > sucrase > catalase. The relativity of three soil enzymes to environmental factor was in order of sucrase > urease > catalase. Because of urease being the most susceptible enzyme to environmental conditions, and it was marked or utmost marked interrelated with vegetation state and soil chemical properties, urease activity could be used as an indicator for the reclamation of wasteland.

  19. Nelumbo nucifera leaf extract mediated synthesis of silver nanoparticles and their antimicrobial properties against some human pathogens

    Science.gov (United States)

    Premanand, G.; Shanmugam, N.; Kannadasan, N.; Sathishkumar, K.; Viruthagiri, G.

    2016-03-01

    In the present report, bio-reduction of silver nitrate into silver nanoparticles using the leaf extract of Nelumbo nucifera is explained. The synthesized nanoparticles exhibited surface Plasmon resonance at 410 nm. The crystalline nature of the biosynthesized silver nanoparticles was confirmed from the X-ray diffraction pattern. The functional groups responsible for bio-reduction of silver nitrate into silver were analyzed by Fourier transform infrared spectroscopy and confirmed by X-ray photoelectron spectrum. Field emission transmission electron microscope micrographs showed the formation of well-separated silver nanoparticles of size in the range of 30-40 nm. The result of dynamic light scattering also confirms the mono-dispersed silver nanoparticles with average size of 35 nm. The synthesized nanoparticles exhibited excellent antibacterial activity against the Gram-positive bacteria B. subtilis.

  20. Laboratory study on the mosquito larvicidal properties of leaf and seed extract of the plant Agave americana.

    Science.gov (United States)

    Dharmshaktu, N S; Prabhakaran, P K; Menon, P K

    1987-04-01

    Experiments on the leaf extract tested against three mosquito species led to 100% mortality of stage 4 Anopheles, Aedes and Culex larvae at a concentration of 0.08% within 24-48 h, whereas 100% mortality of stage 1 larvae occurred at lower concentrations: 0.0032% for Aedes aegypti, 0.016% for Culex quinquefasciatus and 0.08% for Anopheles stephensi, and was more rapid. At the end of 24 h, the highest dilution of the seed extract studied (1:200) produces a larval mortality of 100% for Anopheles and Aedes and 56% for Culex spp., when 4th instar larvae were exposed at room temperature. The comparative mortality in the control group was negligible. One hundred per cent mortality of Anopheles larvae took place by the end of 10 h, and of Aedes larvae by 17 h, at a dilution of 1:200 with water.

  1. Branch Structure of Corona Discharge:Experimental Simulation and Chemical Properties

    Institute of Scientific and Technical Information of China (English)

    邹吉军; 刘昌俊

    2004-01-01

    The branch structure of corona discharge has been investigated via C2H2 corona discharge. Carbon filament with excellent branch structure is formed in the discharge. This carbon filament offers a direct mimic of the branch structure of corona discharge. It providesa very useful way to study on the average energy, physical and chemical characteristics of coronadischarge. On this basis, the chemical property of corona discharge for methane conversion is discussed.

  2. Research and Discussion on Physical and Chemical Properties of Cultivating Substrate with Facilities

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article, by comparing the basic concepts of substrate and soil, their composition of substance and methods of measuring the indexes of physical and chemical properties, analyzes and researches ways of choosing substrate for cultivation with facilities. It indicates that the normal physical and chemical indexes of evaluating a substrate are bulk density, total porosity, non-capillary porosity, ratio of big porosity to small porosity, the pH and the electrical conductivity (EC) value of the substrate. By...

  3. A fundamental research on combustion chemical kinetic model’s precision property

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Uncertainty analysis was used to investigate the precision property of detailed chemical kinetic models.A general-purpose algorithm for assessing and evaluating the impact of uncertainties in chemical kinetic models is presented.The method was also validated through analysis of different kinetic mechanisms applied in the process of modeling NOx emission in methane flame. The algorithm,which provided a basis for further studies,was more efficient and general compared with other methods.

  4. Synthesis of cerium oxide nanoparticles using Gloriosa superba L. leaf extract and their structural, optical and antibacterial properties

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, Ayyakannu, E-mail: sixmuga@yahoo.com [Department of Nanoscience and Technology, Alagappa University, Karaikudi 630 004, Tamil Nadu (India); Karthikeyan, Chandrasekaran; Haja Hameed, Abdulrahman Syedahamed [PG and Research Department of Physics, Jamal Mohamed College, Tiruchirappalli 620 020, Tamil Nadu (India); Gopinath, Kasi; Gowri, Shanmugam; Karthika, Viswanathan [Department of Nanoscience and Technology, Alagappa University, Karaikudi 630 004, Tamil Nadu (India)

    2015-04-01

    CeO{sub 2} nanoparticles (NPs) were green synthesized using Gloriosa superba L. leaf extract. The synthesized nanoparticles retained the cubic structure, which was confirmed by X-ray diffraction studies. The oxidation states of the elements (C (1s), O (1s) and Ce (3d)) were confirmed by XPS studies. TEM images showed that the NPs possessed spherical shape and particle size of 5 nm. The Ce–O stretching bands were observed at 451 cm{sup −1} and 457 cm{sup −1} from the FT-IR and Raman spectra respectively. The band gap of the CeO{sub 2} NPs was estimated as 3.78 eV from the UV–visible spectrum. From the photoluminescence measurements, the broad emission composed of eight different bands were found. The antibacterial studies performed against a set of bacterial strains showed that Gram positive (G +) bacteria were relatively more susceptible to the NPs than Gram negative (G −) bacteria. The toxicological behavior of CeO{sub 2} NPs was found due to the synthesized NPs with uneven ridges and oxygen defects in CeO{sub 2} NPs. - Highlights: • Phytosynthesis of CeO{sub 2} NPs using Gloriosa superba leaf extract • Single step synthesis • Characterized by XRD, XPS, TEM, FTIR, Raman, UV–vis, PL and TG/DTA analyses • CeO{sub 2} NPs were of spherical shape with an average size of 5 nm. • CeO{sub 2} NPs showed highly potent antibacterial activity.

  5. Spectrophotometric Screening of Potent Bactericidal Property of Thevetia Peruviana Schum. Leaf and Fruit Rind Extracts on Clinical and Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Nazneen Rahman

    2014-12-01

    Full Text Available The development of multi drug resistance in human and plant pathogens, reconsidering the traditional medicines as antibacterial source and presence of promising phytochemicals in leaf and fruit rind of T. peruviana (S (Nazneen et al., 2014 prompted the authors to take up the antibacterial evaluation of different extracts. Antibacterial activity, minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of various extracts of T. peruviana (S were measured using methods of National Committee for Clinical Laboratory Standards (NCCLS. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC spectrophotometric determination of active extracts has found that the MICs of all the active extracts lies between the range of 250 μg to 1250 μg and bactericidal concentration in a range of 500 to 1250 μg. The percentage of inhibition was analysed, where in among all the extracts tested against B. subtilis and E. coli, fruit upper liquid (FUL exhibited highest inhibition percentage of 33.75% and 30.31 % at 500 μg/ml respectively. Similarly, fruit hexane (FH extract has the highest inhibition of 15.60% against B. cereus at 750 μg/ml. The Xanthomonas sp. was susceptible to leaf chloroform (LC with 32.29% of inhibition at 1000 μg/ ml. The activity index and total antimicrobial activity indicates the antibacterial action of extracts. The present investigations have revealed that among the extracts, the fruit rind extracts have most prominent inhibition abilities against tested bacteria, which are validating the use of this plant in traditional system of medicine and this is the first report of exploration of above extracts for their antibacterial activities against B. subtilis, B. cereus, E. coli and Xanthomonas sp.

  6. The relationship between chemical structure and dielectric properties of plasma-enhanced chemical vapor deposited polymer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Hao [Materials Sci and Tech Applications, LLC, 409 Maple Springs Drive, Dayton OH 45458 (United States)]. E-mail: hao.jiang@wpafb.af.mil; Hong Lianggou [Materials Sci and Tech Applications, LLC, 409 Maple Springs Drive, Dayton OH 45458 (United States); Venkatasubramanian, N. [Research Institute, University of Dayton, 300 College Park, Dayton, OH 45469-0168 (United States); Grant, John T. [Research Institute, University of Dayton, 300 College Park, Dayton, OH 45469-0168 (United States); Eyink, Kurt [Air Force Research Laboratory, Materials Directorate, 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433-7707 (United States); Wiacek, Kevin [Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth Street, Wright-Patterson Air Force Base, OH 45433-7251 (United States); Fries-Carr, Sandra [Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth Street, Wright-Patterson Air Force Base, OH 45433-7251 (United States); Enlow, Jesse [Air Force Research Laboratory, Materials Directorate, 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433-7707 (United States); Bunning, Timothy J. [Air Force Research Laboratory, Materials Directorate, 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433-7707 (United States)

    2007-02-26

    Polymer dielectric films fabricated by plasma enhanced chemical vapor deposition (PECVD) have unique properties due to their dense crosslinked bulk structure. These spatially uniform films exhibit good adhesion to a variety of substrates, excellent chemical inertness, high thermal resistance, and are formed from an inexpensive, solvent-free, room temperature process. In this work, we studied the dielectric properties of plasma polymerized (PP) carbon-based polymer thin films prepared from two precursors, benzene and octafluorocyclobutane. Two different monomer feed locations, directly in the plasma zone or in the downstream region (DS) and two different pressures, 80 Pa (high pressure) or 6.7 Pa (low pressure), were used. The chemical structure of the PECVD films was examined by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The dielectric constant ({epsilon} {sub r}) and dielectric loss (tan {delta}) of the films were investigated over a range of frequencies up to 1 MHz and the dielectric strength (breakdown voltage) (F {sub b}) was characterized by the current-voltage method. Spectroscopic ellipsometry was performed to determine the film thickness and refractive index. Good dielectric properties were exhibited, as PP-benzene films formed in the high pressure, DS region showed a F{sub b} of 610 V/{mu}m, an {epsilon} {sub r} of 3.07, and a tan {delta} of 7.0 x 10{sup -3} at 1 kHz. The PECVD processing pressure has a significant effect on final film structure and the film's physical density has a strong impact on dielectric breakdown strength. Also noted was that the residual oxygen content in the PP-benzene films significantly affected the frequency dependences of the dielectric constant and loss.

  7. The effect of electron beam irradiation on the mechanical properties of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composites

    Energy Technology Data Exchange (ETDEWEB)

    Siregar, J P; Sapuan, S M [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Rahman, M Z A [Department of Chemistry, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zaman, H M D K, E-mail: januarjasmine@yahoo.com [Radiation Processing Technology Division, Malaysia Nuclear Agency, Bangi 43000 Kajang, Selangor (Malaysia)

    2010-05-15

    The effects of electron beam irradiation on the mechanical properties of pineapple leaf fibre reinforced high impact polystyrene (HIPS) composites were studied. Two types of crosslinking agent that has been used in this study were trimethylolpropane triacrylate (TMPTA) and tripropylene gylcol diacrylate (TPGDA). A 50 wt.% of PALF was blended with HIPS and crosslinking agent using Brabender melt mixer at 165 deg. C. The composites were then irradiated using a 3 MeV electron beam accelerator with dosage of 0-100 kGy. The tensile strength, tensile modulus, flexural strength, flexural modulus, notched and unnotched impat and hardness of composites were measured and the effects of crosslinking agent were also compared.

  8. The effect of electron beam irradiation on the mechanical properties of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composites

    Science.gov (United States)

    Siregar, J. P.; Sapuan, S. M.; Rahman, M. Z. A.; Zaman, H. M. D. K.

    2010-05-01

    The effects of electron beam irradiation on the mechanical properties of pineapple leaf fibre reinforced high impact polystyrene (HIPS) composites were studied. Two types of crosslinking agent that has been used in this study were trimethylolpropane triacrylate (TMPTA) and tripropylene gylcol diacrylate (TPGDA). A 50 wt.% of PALF was blended with HIPS and crosslinking agent using Brabender melt mixer at 165 °C. The composites were then irradiated using a 3 MeV electron beam accelerator with dosage of 0-100 kGy. The tensile strength, tensile modulus, flexural strength, flexural modulus, notched and unnotched impat and hardness of composites were measured and the effects of crosslinking agent were also compared.

  9. Analysis of the chemical and physical properties of combustion aerosols: Properties overview

    Science.gov (United States)

    Aerosol chemical composition is remarkably complex. Combustion aerosols can comprise tens of thousands of organic compounds and fragments, refractory carbon, metals, cations, anions, salts, and other inorganic phases and substituents [Hays et al., 2004]. Aerosol organic matter no...

  10. Chemical structure, synthesis, and physical and chemical properties of porous polymers as materials applied in analytical chemistry and environmental protection

    Directory of Open Access Journals (Sweden)

    Goś Piotr

    2016-12-01

    Full Text Available This article is part of a series devoted to discussing strategies for the synthesis of ion-imprinted polymers and molecularly imprinted polymers, their chemical structure and great potential, which may be used in porous material design, analytical chemistry, environmental protection and other areas of science. The presented work constitutes a basis for a better understanding of what porous polymers are, how we can synthesise them and how to foresee their properties, which can be later used in studies of environmental pollution and analytical chemistry.

  11. Physico-chemical and antioxidant properties of four mango (Mangifera indica L.) cultivars in China.

    Science.gov (United States)

    Liu, Feng-Xia; Fu, Shu-Fang; Bi, Xiu-Fang; Chen, Fang; Liao, Xiao-Jun; Hu, Xiao-Song; Wu, Ji-Hong

    2013-05-01

    Four principal mango cultivars (Tainong No.1, Irwin, JinHwang and Keitt) grown in southern China were selected, and their physico-chemical and antioxidant properties were characterized and compared. Of all the four cultivars, Tainong No.1 had highest content of total phenols, ρ-coumaric acid, sinapic acid, quercetin, titratable acidity, citric acid, malic acid, fructose, higher antioxidant activities (DPPH, FRAP) and L(*), lower pH, PPO activity and individual weight. Keitt mangoes showed significantly (pmangoes exhibited significantly (pmango cultivars to be differentiated clearly based on all these physico-chemical and antioxidant properties determined in the study. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Chemical, physical and morphometric properties of Peruvian carrot (Arracacia xanthorrhiza B.) starch.

    Science.gov (United States)

    Pérez, E E; Borneo, R; Melito, C G; Tovar, J

    1999-01-01

    Starch was isolated from Peruvian carrot (PC)--or arracacha--(Arraccacia xanthorrhiza B.) roots. Its chemical, physical, physicochemical and granular structural properties were compared to those of commercial cassava starch. Scanning electron microscopy revealed a granular size for PC starch ranging between 4 and 26 microns in diameter, with spherical and truncated-egg shapes. PC and cassava starches were similar regarding gross chemical composition and basic physical characteristics but differed in pasting properties, with PC starch showing lower breakdown and consistency indices. The two starches also showed different water absorption and solubility patterns.

  13. Method for Non-Invasive Determination of Chemical Properties of Aqueous Solutions

    Science.gov (United States)

    Todd, Paul W. (Inventor); Jones, Alan (Inventor); Thomas, Nathan A. (Inventor)

    2016-01-01

    A method for non-invasively determining a chemical property of an aqueous solution is provided. The method provides the steps of providing a colored solute having a light absorbance spectrum and transmitting light through the colored solute at two different wavelengths. The method further provides the steps of measuring light absorbance of the colored solute at the two different transmitted light wavelengths, and comparing the light absorbance of the colored solute at the two different wavelengths to determine a chemical property of an aqueous solution.

  14. Review on palladium-containing perovskites: synthesis, physico-chemical properties and applications in catalysis.

    Science.gov (United States)

    Essoumhi, Abdellatif; El Kazzouli, Saïd; Bousmina, Mosto

    2014-02-01

    This review reports on the recent advances in the synthesis and physico-chemical properties of palladium-containing perovskites. Initially, the perovskite structure is briefly reviewed, then palladium-containing perovskites synthesis and physico-chemical properties are detailed. The applications of palladium-containing perovskites in catalysis; namely, NO reduction, methane combustion, methanol as well as ethanol oxidation, are briefly highlighted. The involvement and the important contribution of palladium-containing perovskites in cross-coupling reactions, especially Suzuki-Miyaura, Sonogashira, Ulmann and Grignard, are discussed.

  15. The effects of motive gas physical properties on the performance of ejector for chemical lasers

    Science.gov (United States)

    Jin, Jungkun; Kim, Sehoon; Kwon, Hyuckmo; Kwon, Sejin

    2005-03-01

    Axi-symmetric annular type ejector has been developed as a pressure recovery system for HF/DF chemical laser. Ejector was tested using air as operating gases and low-pressure entrained flow was obtained. In this paper, we changed motive gas since operating gases for chemical laser system are products of chemical reaction. By selection of motive gas, physical properties of operating gas changes, therefore the performance of ejector is different for each motive gas, i.e., specific heat at constant pressure (CP) and average molecular weight (MW) on the effectiveness of ejection. The research was carried out by both numerical analysis using commercial CFD code, FLUENT and experiments.

  16. Quantum chemical studies on structural, vibrational, nonlinear optical properties and chemical reactivity of indigo carmine dye

    Science.gov (United States)

    El-Mansy, M. A. M.

    2017-08-01

    Structural and vibrational spectroscopic studies were performed on indigo carmine (IC) isomers using FT-IR spectral analysis along with DFT/B3LYP method utilizing Gaussian 09 software. GaussView 5 program has been employed to perform a detailed interpretation of vibrational spectra. Simulation of infrared spectra has led to an excellent overall agreement with the observed spectral patterns. Mulliken population analyses on atomic charges, MEP, HOMO-LUMO, NLO, first order hyperpolarizability and thermodynamic properties have been examined by (DFT/B3LYP) method with the SDD basis set level. Density of state spectra (DOS) were calculated using GaussSum 3 at the same level of theory. Molecular modeling approved that DOS Spectra are the most significant tools for differentiating between two IC isomers so far. Moreover, The IC isomers (cis-isomer) have shown an extended applicability for manufacturing both NLO and photovoltaic devices such as solar cells.

  17. Mechanical and Chemical Properties of Bamboo/Glass Fibers Reinforced Polyester Composites

    Directory of Open Access Journals (Sweden)

    K.Sudha Madhuri,

    2016-01-01

    Full Text Available The chemical resistance of Bamboo/Glass reinforced Polyester hybrid composites to acetic acid, Nitric acid, Hydrochloric acid, Sodium hydroxide, Sodium carbonate, Benzene, Toluene, Carbon tetrachloride and Water was studied. The tensile and impact properties of these composites were also studied. The effect of alkali treatment of bamboo fibers on these properties was studied. It was observed that the tensile and impact properties of the hybrid composites increase with glass fiber content. The author investigated the interfacial bonding between Glsss/Bamboo fiber composites by SEM. These properties found to be higher when alkali treated bamboo fibers were used in hybrid composites. The hybrid fiber composites showed better resistance to the chemicals mentioned above. The elimination of amorphous hemi-cellulose with alkali treatment leading to higher crystallinity of the bamboo fibers with alkali treatment may be responsible for these observations.

  18. Change in hydraulic properties and leaf traits in a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Directory of Open Access Journals (Sweden)

    B. Schuldt

    2011-08-01

    Full Text Available A large-scale replicated throughfall exclusion experiment was conducted in a pre-montane perhumid rainforest in Sulawesi (Indonesia exposing the trees for two years to pronounced soil desiccation. The lack of regularly occurring dry periods and shallow rooting patterns distinguish this experiment from similar experiments conducted in the Amazonian rainforest. We tested the hypotheses that a tree's sun canopy is more affected by soil drought than its shade crown, making tall trees particularly vulnerable even under a perhumid climate, and that extended drought periods stimulate an acclimation in the hydraulic system of the sun canopy. In the abundant and tall tree species Castanopsis acuminatissima (Fagaceae, we compared 31 morphological, anatomical, hydraulic and chemical variables of leaves, branches and the stem together with stem diameter growth between drought and control plots.

    There was no evidence of canopy dieback. However, the drought treatment led to a 30 % reduction in sapwood-specific hydraulic conductivity of sun canopy branches, possibly caused by the formation of smaller vessels and/or vessel filling by tyloses. Drought caused an increase in leaf size, but a decrease in leaf number, and a reduction in foliar calcium content. The δ13C and δ18O signatures of sun canopy leaves gave no indication of a permanent down-regulation of stomatal conductance during the drought, indicating that pre-senescent leaf shedding may have improved the water status of the remaining leaves. Annual stem diameter growth decreased during the drought, while the density of wood in the recently produced xylem increased in both the stem and sun canopy branches (marginally significant. The sun canopy showed a more pronounced drought response than the shade crown indicating that tall trees with a large sun canopy are more vulnerable to drought stress.

    We conclude that the extended drought prompted a number of

  19. Change in hydraulic properties and leaf traits in a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Science.gov (United States)

    Schuldt, B.; Leuschner, C.; Horna, V.; Moser, G.; Köhler, M.; van Straaten, O.; Barus, H.

    2011-08-01

    A large-scale replicated throughfall exclusion experiment was conducted in a pre-montane perhumid rainforest in Sulawesi (Indonesia) exposing the trees for two years to pronounced soil desiccation. The lack of regularly occurring dry periods and shallow rooting patterns distinguish this experiment from similar experiments conducted in the Amazonian rainforest. We tested the hypotheses that a tree's sun canopy is more affected by soil drought than its shade crown, making tall trees particularly vulnerable even under a perhumid climate, and that extended drought periods stimulate an acclimation in the hydraulic system of the sun canopy. In the abundant and tall tree species Castanopsis acuminatissima (Fagaceae), we compared 31 morphological, anatomical, hydraulic and chemical variables of leaves, branches and the stem together with stem diameter growth between drought and control plots. There was no evidence of canopy dieback. However, the drought treatment led to a 30 % reduction in sapwood-specific hydraulic conductivity of sun canopy branches, possibly caused by the formation of smaller vessels and/or vessel filling by tyloses. Drought caused an increase in leaf size, but a decrease in leaf number, and a reduction in foliar calcium content. The δ13C and δ18O signatures of sun canopy leaves gave no indication of a permanent down-regulation of stomatal conductance during the drought, indicating that pre-senescent leaf shedding may have improved the water status of the remaining leaves. Annual stem diameter growth decreased during the drought, while the density of wood in the recently produced xylem increased in both the stem and sun canopy branches (marginally significant). The sun canopy showed a more pronounced drought response than the shade crown indicating that tall trees with a large sun canopy are more vulnerable to drought stress. We conclude that the extended drought prompted a number of medium- to long-term responses in the leaves, branches and the trunk

  20. Cationic triangulenes and helicenes: synthesis, chemical stability, optical properties and extended applications of these unusual dyes.

    Science.gov (United States)

    Bosson, Johann; Gouin, Jérôme; Lacour, Jérôme

    2014-04-21

    Cationic triangulenes and helicenes are highly stable carbocations with planar and helical conformations respectively. These moieties are effective dyes with original absorption and emission properties. Over the last decade, they have received greater attention and are considered as valuable tools for the development of innovative applications. In this review, the synthesis of these unique compounds is presented together with their core chemical and physical properties. Representative applications spanning from surface sciences to biology and chemistry are presented.

  1. Impact of Biofield Treatment on Chemical and Thermal Properties of Cellulose and Cellulose Acetate

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Cellulose being an excellent biopolymer has cemented its place firmly in many industries as a coating material, textile, composites, and biomaterial applications. In the present study, we have investigated the effect of biofield treatment on physicochemical properties of cellulose and cellulose acetate. The cellulose and cellulose acetate were exposed to biofield and further the chemical and thermal properties were investigated. X-ray diffraction study asserted that the biofield treatment did...

  2. The quantum-chemical determination of group contributions to the thermodynamic properties of organophosphorus compounds

    Science.gov (United States)

    Dorofeeva, O. V.; Ryzhova, O. N.; Moiseeva, N. F.

    2008-06-01

    The enthalpies of formation, entropies, and heat capacities of 95 organophosphorus derivatives calculated by nonempirical quantum-chemical methods were used to develop the additive method for estimating the thermodynamic properties of these compounds. 86 group contribution values were obtained for estimating the thermodynamic properties of diverse organic derivatives of phosphorus in the oxidation states 3 and 5 (three-and four-coordinate phosphorus atoms).

  3. Changes in petiole hydraulic properties and leaf water flow in birch and oak saplings in a CO{sub 2}-enriched atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, N.; Morii, N.; Koike, T. [Hokkaido Univ., Sapporo (Japan). Graduate School of Agriculture; Ueda, T. [Hokkaido DALTON, Sapporo (Japan); Funada, R. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan). Faculty of Agriculture; Takagi, K.; Hiura, T.; Sasa, K. [Hokkaido Univ., Sapporo (Japan). Forests, Field Science Center for Northern Biosphere

    2008-02-15

    This study examined the water flow and petiole hydraulic properties in the individual leaves of Betula maximowicziana Regel and ring-porous Quercus mongolica Fish. ex Ledeb ssp. crispula Menitsky. The aim of the study was to examine the relationship between water flow, hydraulic properties and elevated carbon dioxide (CO2). The effects of elevated CO{sub 2} on sun and shade leaves of 2 petioles were investigated in order to examine structural changes in response to CO{sub 2}. The study was conducted at the Sapporo Experimental Forest in Japan, where a free air CO{sub 2} enrichment system was used to maintain CO{sub 2} levels. Results of the study demonstrated that elevated CO{sub 2} levels consistently decreased water flow, including leaf-specific hydraulic conductivity and total vessel area of the petiole in leaves exposed to the sun. Elevated CO{sub 2} levels had no impact on the hydraulic conductivity of shade leaves. It was concluded that changes in water flow were also associated with changes in petiole hydraulic properties. 57 refs., 2 tabs., 4 figs.

  4. Influence of Soda Pulping Variables on Properties of Pineapple (Ananas comosus Merr. Leaf Pulp and Paper Studied by Face-Centered Composite Experimental Design

    Directory of Open Access Journals (Sweden)

    Jantharat Wutisatwongkul

    2016-01-01

    Full Text Available Face-centered composite design (FCC was used to study the effect of pulping variables: soda concentration (4-5 wt%, temperature (90–130°C, and pulping time (20–60 min on the properties of pineapple leaf pulp and paper employing soda pulping. Studied pulp responses were screened yield and lignin content (kappa number. Paper properties, which include tensile index, burst index, and tear index, were also investigated. Effects of the pulping variables on the properties were statistically analyzed using Minitab 16. The optimum conditions to obtain the maximum tensile index were soda concentration of 4 wt%, pulping temperature of 105°C, and pulping time of 20 min. The predicted optimum conditions provided tensile index, burst index, tear index, screened yield, and kappa number of 44.13 kN·m/kg, 1.76 kPa·m2, 1.68 N·m2/kg, 21.29 wt%, and 28.12, respectively, and were experimentally confirmed.

  5. Development of pure component property models for chemical product-process design and analysis

    DEFF Research Database (Denmark)

    Hukkerikar, Amol Shivajirao

    Property prediction models based on the group-contribution+ (GC+) approach have been developed to provide reliable predictions of pure component properties together with uncertainties of predicted property values which is much needed information in performing chemical product and process design...... the CAPEC database, the US Environmental Protection Agency (EPA) database, and the USEtox database are used. In total, 21 thermo-physical properties and 22 environmental-related properties of pure components which include normal boiling point, critical constants, standard enthalpy of formation, liquid...... be applied to a wide range of properties of pure components. pure components. In this work, however, the application of ‘molecular structural similarity criteria’ is illustrated by considering performance improvement of models for enthalpy of formation, enthalpy of fusion, and critical temperature. For all...

  6. Soil chemical properties affect the reaction of forest soil bacteria to drought and rewetting stress.

    Science.gov (United States)

    Chodak, Marcin; Gołębiewski, Marcin; Morawska-Płoskonka, Justyna; Kuduk, Katarzyna; Niklińska, Maria

    Reaction of soil bacteria to drought and rewetting stress may depend on soil chemical properties. The objectives of this study were to test the reaction of different bacterial phyla to drought and rewetting stress and to assess the influence of different soil chemical properties on the reaction of soil bacteria to this kind of stress. The soil samples were taken at ten forest sites and measured for pH and the contents of organic C (Corg) and total N (Nt), Zn, Cu, and Pb. The samples were kept without water addition at 20 - 30 °C for 8 weeks and subsequently rewetted to achieve moisture equal to 50 - 60 % of their maximum water-holding capacity. Prior to the drought period and 24 h after the rewetting, the structure of soil bacterial communities was determined using pyrosequencing of 16S rRNA genes. The drought and rewetting stress altered bacterial community structure. Gram-positive bacterial phyla, Actinobacteria and Firmicutes, increased in relative proportion after the stress, whereas the Gram-negative bacteria in most cases decreased. The largest decrease in relative abundance was for Gammaproteobacteria and Bacteroidetes. For several phyla the reaction to drought and rewetting stress depended on the chemical properties of soils. Soil pH was the most important soil property influencing the reaction of a number of soil bacterial groups (including all classes of Proteobacteria, Bacteroidetes, Acidobacteria, and others) to drought and rewetting stress. For several bacterial phyla the reaction to the stress depended also on the contents of Nt and Corg in soil. The effect of heavy metal pollution was also noticeable, although weaker compared to other chemical soil properties. We conclude that soil chemical properties should be considered when assessing the effect of stressing factors on soil bacterial communities.

  7. International Research Project on the Effects of Chemical Ageing of Polymers on Performance Properties: Chemical and Thermal Analysis

    Science.gov (United States)

    Bulluck, J. W.; Rushing, R. A.

    1996-01-01

    Work during the past six months has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted small changes in the molecular weight distribution. Again these changes may result in variations in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Ultra- Violet Scanning Analysis, GC/Mass Spectrometry, Differential Scanning Calorimetry and Thermomechanical Analysis. In the ultra-violet analysis we noted the presence of an absorption band indicative of triene formation. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. We also cast films at SWT and subjected these films to a refluxing methanol 1% ethylene diamine solution. An updated literature search was conducted using Dialog and DROLLS to identify any new papers that may have been published in the open literature since the start of this project. The updated literature search and abstracts are contained in the Appendix section of this report.

  8. Further insights into chemical characterization through GC-MS and evaluation for anticancer potential of Dracaena draco leaf and fruit extracts.

    Science.gov (United States)

    Valente, Maria João; de Pinho, Paula Guedes; Henrique, Rui; Pereira, José A; Carvalho, Márcia

    2012-10-01

    The present study reports for the first time the amino acid and fatty acid compositions and the antitumoral activity of aqueous extracts obtained from Dracaena draco L. leaf and fruit. Metabolite profiles were determined by gas chromatography-ion trap-mass spectrometry (GC-IT-MS), with several amino acids, palmitic, linolenic and stearic acid being identified in the leaf extract, and only proline, oleic and stearic acid in the fruit extract. The in vitro antiproliferative activities of the extracts were tested against human colon (Caco-2), kidney (A-498), and liver (HepG2) cancer cell lines. In addition, primary cultures of normal and cancerous renal cells derived from kidney cancer patients were treated with D. draco extracts (0-400 μg/mL). Antiproliferative and cytotoxic effects were determined by the MTT assay. D. draco extracts inhibited proliferation of human colon and renal tumor cells in vitro, whereas no or weak effect was observed in HepG2 cells. Compared to the fruit extract, D. draco leaf extract exhibited stronger antiproliferative activity against all cancer cells. Our results indicate that D. draco, particularly the leaf, may be useful as a cancer chemopreventive and/or chemotherapeutic agent for colon and kidney cancers.

  9. Utilization of Cellulose from Pineapple Leaf Fibers as Nanofiller in Polyvinyl Alcohol-Based Film

    Directory of Open Access Journals (Sweden)

    Kendri Wahyuningsih

    2016-08-01

    Full Text Available Cellulose from pineapple leaf fibers as one of the natural polymer which has biodegradable property in a nanometer’s scale, can be formed as a filler in composite of Poly(vinyl Alcohol/PVA is expected to increase the physical, thermal, and barrier properties of composite films similar to conventional plastic. The aim of this study was to examine the effect of fibrillation of cellulose fibers from pineapple leaf fibers using a combined technique of chemical-mechanical treatments, to investigate the reinforcing effect of concentration of nanocellulose fibrils in the polyvinyl alcohol (PVA matrix on physical properties, thermal properties, water vapor transmission rate, light transmittance and morphological with and without addition of glycerol. Nanocellulose was made from cellulose of pineapple leaf fiber using wet milling (Ultra Fine Grinder. The composite film production was carried out by using casting solution method by mixing PVA solution with nanocellulose (10-50% and glycerol (0-1%. The characterization of film covered physical properties (thickness, moisture content and density, thermal properties, permeability (WVTR, light transmittance, morphology, and crystallinity. Nanocellulose from pineapple leaf fibers was produced by Ultra Fine Grinder shows that the size reduction process was accurate. Nanocellulose addition on PVA composite film was affected to increasing the physical, thermal, and barrier properties. Meanwhile, decreasing the percentage of composite film transmittance, thus the transparency decrease (opaque. Water vapor transmission rate (WVTR the film was increased with increasing glycerol concentration, but the physical and thermal properties was decreased.

  10. Synthesis of cerium oxide nanoparticles using Gloriosa superba L. leaf extract and their structural, optical and antibacterial properties.

    Science.gov (United States)

    Arumugam, Ayyakannu; Karthikeyan, Chandrasekaran; Haja Hameed, Abdulrahman Syedahamed; Gopinath, Kasi; Gowri, Shanmugam; Karthika, Viswanathan

    2015-04-01

    CeO2 nanoparticles (NPs) were green synthesized using Gloriosa superba L. leaf extract. The synthesized nanoparticles retained the cubic structure, which was confirmed by X-ray diffraction studies. The oxidation states of the elements (C (1s), O (1s) and Ce (3d)) were confirmed by XPS studies. TEM images showed that the NPs possessed spherical shape and particle size of 5nm. The Ce-O stretching bands were observed at 451cm(-1) and 457cm(-1) from the FT-IR and Raman spectra respectively. The band gap of the CeO2 NPs was estimated as 3.78eV from the UV-visible spectrum. From the photoluminescence measurements, the broad emission composed of eight different bands were found. The antibacterial studies performed against a set of bacterial strains showed that Gram positive (G+) bacteria were relatively more susceptible to the NPs than Gram negative (G-) bacteria. The toxicological behavior of CeO2 NPs was found due to the synthesized NPs with uneven ridges and oxygen defects in CeO2 NPs. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. AROMA PROFILE AND ANTIMICROBIAL PROPERTIES OF ALCOHOLIC AND AQUEOUS EXTRACTS FROM ROOT, LEAF AND STALK OF NETTLE (Urtica dioica L.

    Directory of Open Access Journals (Sweden)

    Razzagh Mahmoudi

    2014-12-01

    Full Text Available Medicinal plant can be considered as a great source of new antimicrobial agents due to their enormous therapeutic potential and limited side effects. Nettle (Urtica dioica L. is a widespread and common medicinal plant widely used in traditional medicine. The present study investigates the antimicrobial potency of alcoholic and aqueous extracts of Urtica dioica on some gram positive and negative bacteria and also a particular type of fungi and analyzes the extracts to find the active ingredients by gas chromatography-mass spectroscopy (GC-MS method. Results from disc diffusion assay indicated that water extract of root, leaf and stalk had the highest antimicrobial activity respectively and caused significant inhibition zones in P. vulgaris, L. monocytogenes and K. pneumoniae cultures. Antimicrobial efficacy of ethanol extracts was higher in root extract which caused high growth inhibition zones in P. vulgaris, K. pneumoniae and S. aureus cultures. MBC and MIC experiments of the ethanol extract illustrated that the most powerful antimicrobial effect was related to the stem organ extract on K. pnuomonae and S. aureus bacteria. Highest level of antibacterial effects in root can be due to its higher concentration of contents compared to other organs. Based on these results it can be suggested that Urtica dioica and its water and ethanol extracts have noticeable antimicrobial effects against gram negative, positive and Candida albicans fungi that may be applicable as a prophylactic or therpeutic antimicrobial agent in both human and animals.

  12. Repellent properties of Cardiospermum halicacabum Linn. (Family:Sapindaceae) plant leaf extracts against three important vector mosquitoes

    Institute of Scientific and Technical Information of China (English)

    M Govindarajan; R Sivakumar

    2012-01-01

    Objective: To determine repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Cardiospermum halicacabum (C. halicacabum) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).Methods:Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of three mosquito species and were assayed in the laboratory condition by using the protocol of WHO 2005; The plant leaf crude extracts of C. halicacabum was applied at 1.0, 2.5, and 5.0 mg/cm2 separately in the exposed area of the fore arm. Only ethanol served as control. Results: In this observation, the plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity was dependent on the strength of the plant extracts. The tested plant crude extracts had exerted promising repellent against all the three mosquitoes. Conclusions: From the results it can be concluded the crude extract of C. halicacabum was potential for controlling Cx. quinquefasciatus,Ae. aegypti and An. stephensi mosquitoes.

  13. A detailed comparative study between chemical and bioactive properties of Ganoderma lucidum from different origins

    NARCIS (Netherlands)

    Stojkovic, D.S.; Barros, L.; Calhelha, R.C.; Glamoclija, J.; Ciric, A.; Griensven, van L.J.L.D.; Sokovic, M.; Ferreira, I.C.F.R.

    2014-01-01

    A detailed comparative study on chemical and bioactive properties of wild and cultivated Ganoderma lucidum from Serbia (GS) and China (GCN) was performed. This species was chosen because of its worldwide use as medicinal mushroom. Higher amounts of sugars were found in GS, while higher amounts of or

  14. Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

    NARCIS (Netherlands)

    Tijsma, E.J.; Does, van der L.; Bantjes, A.; Vulic, I.

    1994-01-01

    The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal p

  15. Properties of alumina films by atmospheric pressure metal-organic chemical vapour deposition

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Corbach, van H.D.; Fransen, T.; Gellings, P.J.

    1994-01-01

    Thin alumina films were deposited at low temperatures (290–420°C) on stainless steel, type AISI 304. The deposition process was carried out in nitrogen by metal-organic chemical vapour deposition using aluminum tri-sec-butoxide. The film properties including the protection of the underlying substrat

  16. Physico-Chemical and Structural Properties of DeNOx and SO2 Oxidation Catalysts

    DEFF Research Database (Denmark)

    Masters, Stephen Grenville; Oehlers, Cord; Nielsen, Kurt;

    1996-01-01

    Commercial catalysts for NOx removal and SO2 oxidation and their model systems have been investigated by spectroscopic, thermal, electrochemical and X-ray methods. Structural information on the vanadium complexes and compounds as well as physico-chemical properties for catalyst model systems have...... been obtained. The results are discussed in relation to proposed reaction mechanisms....

  17. Structural properties of produced CuO/NiO/glass thin layers Produced by chemical method

    Directory of Open Access Journals (Sweden)

    A. Ramezani

    2016-12-01

    Full Text Available Nickel Oxide and Copper oxide on Nickel Oxide thin layers were produced by chemical bath deposition method. There nano structures were investigated by SEM and EDAX analysis. By producing CuO/NiO/glass sandwich layers nano structure of NiO/glass layer changed and fraction of voids decreases. In sandwich layer physical property of outer layer was dominant

  18. CHARACTERIZATION OF ACTIVATED CARBONS' PHYSICAL AND CHEMICAL PROPERTIES IN RELATION TO THEIR MERCURY ADSORPTION

    Science.gov (United States)

    The paper gives results of a characterization of the physical and chemical properties of the activated carbons used for elemental mercury (Hgo) adsorption, in order to understand the role of oxygen surface functional groups on the mechanism of Hgo adsorption by activated carbons....

  19. Pelleted biochar: chemical and physical properties show potential use as a substrate in container nurseries

    Science.gov (United States)

    R. Kasten Dumroese; Juha Heiskanen; Karl Englund; Arja Tervahauta

    2011-01-01

    We found that peat moss, amended with various ratios of pellets comprised of equal proportions of biochar and wood flour, generally had chemical and physical properties suitable for service as a substrate during nursery production of plants. High ratios of pellets to peat (>50%) may be less desirable because of high C:N, high bulk density, swelling associated with...

  20. Soil physical and chemical properties of cacao farms in the south western region of cameroon

    Science.gov (United States)

    The low macro nutrient content (K, Ca and Mg) in soils under cacao is one of the major causes of the poor cacao (Theobroma cacao L) yields. Efforts were made to assess the major physical and chemical properties of soils from some important cacao zones of the South West Region of Cameroon in order t...

  1. Distribution of Fish in the Upper Citarum River: an Adaptive Response to Physico-Chemical Properties

    Directory of Open Access Journals (Sweden)

    SUNARDI

    2012-12-01

    Full Text Available Distribution of fish in river is controlled by physico-chemical properties of the water which is affected by land-use complexity and intensity of human intervention. A study on fish distribution was carried out in the upper Citarum River to map the effects of physio-chemical properties on habitat use. A survey was conducted to collect fish and to measure the water quality both on dry and rainy season. The result showed that distribution of the fish, in general, represented their adaptive response to physico-chemical properties. The river environment could be grouped into two categories: (i clean and relatively unpolluted sites, which associated with high DO and water current, and (ii polluted sites characterized by low DO, high COD, BOD, water temperature, NO3, PO4, H2S, NH3, and surfactant. Fish inhabiting the first sites were Xiphophorus helleri, Punctius binotatus, Xiphophorus maculatus, and Oreochromis mossambicus. Meanwhile, the latter sites were inhabited by Liposarcus pardalis, Trichogaster trichopterus, and Poecilia reticulata. Knowledge about fish distribution in association with the pysico-chemical properties of water is crucial especially for the river management.

  2. Model Experiments on Chemical Properties of Superheavy Elements in Aqueous Solutions

    CERN Document Server

    Szeglowski, Z

    2003-01-01

    This paper presents a brief review of model experiments on investigation of chemical properties of transactinide elements, ranging from 104 to 116. The possibilities of isolation of the nuclei of these elements from nuclear reaction products, using the ion-exchange method, are also considered.

  3. Chemical interesterification of blends of palm stearin, coconut oil, and canola oil: physicochemical properties.

    Science.gov (United States)

    Soares, Fabiana Andreia Schäfer De Martini; da Silva, Roberta Claro; Hazzan, Márcia; Capacla, Isabele Renata; Viccola, Elise Raduan; Maruyama, Jessica Mayumi; Gioielli, Luiz Antonio

    2012-02-15

    trans-Free interesterified fat was produced for possible usage as a margarine. Palm stearin, coconut oil, and canola oil were used as substrates for chemical interesterification. The main aim of the present study was to evaluate the physicochemical properties of blends of palm stearin, coconut oil, and canola oil submitted to chemical interesterification using sodium methoxide as the catalyst. The original and interesterified blends were examined for fatty acid composition, softening and melting points, solid fat content, and consistency. Chemical interesterification reduced softening and melting points, consistency, and solid fat content. The interesterified fats showed desirable physicochemical properties for possible use as a margarine. Therefore, our result suggested that the interesterified fat without trans-fatty acids could be used as an alternative to partially hydrogenated fat.

  4. Chemical Properties of Carbon Nanotubes Prepared Using Camphoric Carbon by Thermal-CVD

    Science.gov (United States)

    Azira, A. A.; Rusop, M.

    2010-03-01

    Chemical properties and surface study on the influence of starting carbon materials by using thermal chemical vapor deposition (Thermal-CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from camphor were synthesized as the precursor material due to low sublimation temperature. The major parameters are also evaluated in order to obtain high-yield and high-quality CNTs. The prepared CNTs are examined using field emission scanning electron microscopy (FESEM) to determine the microstructure of nanocarbons. The FESEM investigation of the CNTs formed on the support catalysts provides evidence that camphor is suitable as a precursor material for nanotubes formation. The chemical properties of the CNTs were conducted using FTIR spectroscopy and PXRD analysis. The high-temperature graphitization process induced by the Thermal-CVD enables the hydrocarbons to act as carbon sources and changes the aromatic species into the layered graphite structure of CNTs.

  5. FORTRAN 4 computer program for calculation of thermodynamic and transport properties of complex chemical systems

    Science.gov (United States)

    Svehla, R. A.; Mcbride, B. J.

    1973-01-01

    A FORTRAN IV computer program for the calculation of the thermodynamic and transport properties of complex mixtures is described. The program has the capability of performing calculations such as:(1) chemical equilibrium for assigned thermodynamic states, (2) theoretical rocket performance for both equilibrium and frozen compositions during expansion, (3) incident and reflected shock properties, and (4) Chapman-Jouguet detonation properties. Condensed species, as well as gaseous species, are considered in the thermodynamic calculation; but only the gaseous species are considered in the transport calculations.

  6. Assessing the Effect of Organic Compounds, Biofertilizers and Chemical Fertilizers on Morphological Properties,yield and Yield Components of Forage Sorghum (Sorghum bicolor

    Directory of Open Access Journals (Sweden)

    A.H Saeidnejad

    2012-12-01

    Full Text Available Recently, using the source of organic fertilizers and biofertilizers in sustainable crop production is growing. In order to evaluate the effect of organic compounds, biofertilizers and chemical fertilizer on morphological properties, yield and yield components of forage Sorghum (sorghum bicolor a field experiment was conducted in the Research Farm, College of Agriculture, Ferdowsi University of Mashhad in 2008.The treatments were seed inoculation with the combination of Azotobacter chroococcum and Azospirillum brasilense, Compost (15 t/ha, Vermicompost (10 t/ha, seed inoculation with Azotobacter and Azospirillum and compost (10t/ha, seed inoculation with Azotobacter chroococcum and Azospirillum brasilense and Vermicompost (7t/ha, seed inoculation with Pseudomonas flurescence, seed inoculation with Pseudomonas flurescence and Azotobacter chroococcum and Azospirillum brasilense combination, seed inoculation with Pseudomonas flurescence and compost (15t/ha, chemical fertilizer (80 kg/h urea fertilizer and 50 kg/h super phosphate fertilizer and control. Harvesting was performed in 2 cuts in flowering stage. Plant height, number of tiller per plant and SPAD reading was significantly affected by the treatments. Stem diameter was not affected by any treatments. There was a significant difference among all treatments in terms of fresh and dry forage yield. There were no significant differences among all treatments in terms of stem and leaf dry matter. In general, result of this experiment indicated that organic amendments and biofertilizers could be acceptable alternatives for chemical fertilizers.

  7. The impact of the chemical synthesis on the magnetic properties of intermetallic PdFe nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos-Rubio, I.; Insausti, M.; Muro, I. Gil de [Universidad del País Vasco, UPV/EHU, Dpto. de Química Inorgánica (Spain); Arias-Duque, D. Carolina; Hernández-Garrido, Juan Carlos [Universidad de Cadiz, Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias (Spain); Rojo, T.; Lezama, L., E-mail: luis.lezama@ehu.es [Universidad del País Vasco, UPV/EHU, Dpto. de Química Inorgánica (Spain)

    2015-05-15

    Palladium-rich Iron nanoparticles in the 4–8 nm range have been produced by a combination of two methods: the thermal decomposition of organometallic precursors and the reduction of metallic salts by a polyol. Herein, it is shown how the details of the synthesis have a striking impact on the magnetic and morphological properties of the final products. In the synthesis of these bimetallic nanoparticles, the use of high reaction temperatures plays an essential role in attaining good chemical homogeneity, which has proved to have a key influence on the magnetic properties. Magnetic characterization has been performed by electron magnetic resonance and magnetization measurements, which have confirmed the superparamagnetic-like behavior at room temperature. No clear traces of magnetic polarization in palladium atoms have been detected. The combination of long-term stability and homogeneous chemical and magnetic properties makes these particles very suitable for a wide range of applications in nanotechnology.

  8. Properties of 15HN Steel after Various Thermo-Chemical Treatments

    Directory of Open Access Journals (Sweden)

    L. Klimek

    2007-07-01

    Full Text Available The aim of conducted research was to find universal steel that may serve to regenerate machine elements by MULTIPLEX method – or cladding of alloy steel and then subjecting to thermo-chemical treatment. This paper presents the results of metallographic examination, hardness distribution and selected tribological properties of vacuum carburized, sulphonitrided and vacuum nitrided layers obtained on 15HN steel. The results demonstrate that on 15HN steel (carburizing steel, nitrided and sulphonitrided layers show good durability and tribological properties. Therefore, it is possible to use it to regenerate machine elements by cladding method and then treat them by different thermo-chemical ways in order to obtain desired properties.

  9. Structural, chemical and magnetic properties of secondary phases in Co-doped ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Ney, A; Ney, V; Ye, S; Ollefs, K; Kammermeier, T [Fakultaet fuer Physik and CeNIDE, Universitaet Duisburg-Essen, Lotharstrasse 1, D-47057 Duisburg (Germany); Kovacs, A; Dunin-Borkowski, R E [Center for Electron Nanoscopy, Technical University of Denmark, DK-2800 Kgs Lyngby (Denmark); Wilhelm, F; Rogalev, A, E-mail: andreas.ney@uni-due.de [European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France)

    2011-10-15

    We have utilized a comprehensive set of experimental techniques such as transmission electron microscopy (TEM) and synchrotron-based x-ray absorption spectroscopy (XAS) and the respective x-ray linear dichroism and x-ray magnetic circular dichroism to characterize the correlation of structural, chemical and magnetic properties of Co-doped ZnO samples. It can be established on a quantitative basis that the superparamagnetic (SPM) behavior observed by integral superconducting quantum interference device magnetometry is not an intrinsic property of the material but stems from precipitations of metallic Co. Their presence is revealed by TEM as well as XAS. Annealing procedures for these SPM samples were also studied, and the observed changes in the magnetic properties found to be due to a chemical reduction or oxidation of the metallic Co species. (paper)

  10. Effects of reprocessing on chemical and morphological properties of guide wires used in angioplasty

    Directory of Open Access Journals (Sweden)

    Rogério Valentim Gelamo

    2013-09-01

    Full Text Available OBJECTIVE: To investigate the influence of the reprocessing technique of enzymatic bath with ultrasonic cleaning and ethylene oxide sterilization on the chemical properties and morphological structure of polymeric coatings of guide wire for regular guiding catheter. METHODS: These techniques simulated the routine of guide wire reprocessing in many hemodynamic services in Brazil and other countries. Samples from three different manufacturers were verified by scanning electron microscopy and X-ray photoelectron spectroscopy. RESULTS: A single or double sterilization of the catheters with ethylene oxide was not associated with morphological or chemical changes. However, scanning electron microscopy images showed that the washing method was associated with rough morphological changes, including superficial holes and bubbles, in addition to chemical changes of external atomic layers of polymeric coating surfaces, as detected by the X-ray photoelectron spectroscopy method, which is compatible with extended chemical changes on catheter surfaces. CONCLUSION: The reprocessing of the catheters with ethylene oxide was not associated with morphological or chemical changes, and it seemed appropriate to maintain guide wire coating integrity. However, the method combining chemical cleaning with mechanical vibration resulted in rough anatomical and chemical surface deterioration, suggesting that this reprocessing method should be discouraged.

  11. Spatial Variability of Soil Chemical Properties in the Reclaiming Marine Foreland to Yellow Sea of China

    Institute of Scientific and Technical Information of China (English)

    WEI Yi-chang; BAI You-lu; JIN Ji-yun; ZHANG Fang; ZHANG Li-ping; LIU Xiao-qiang

    2009-01-01

    Precise information about the spatial variability of soil properties is essential in developing site-specific soil management,such as variable rate application of fertilizers.In this study the sampling grid of 100 m×100 m was established to collect 1703 soil samples at the depth of 0-20 cm,and examine spatial patterns including 13 soil chemical properties (pH,OM,NH4+,PK,Ca,Mg,S,B,Cu,Fe,Mn,and Zn) in a 1760 ha rice field in Haifeng farm,China,from 6th to 22nd of April,2006,before fertilizer application and planting.Soil analysis was performed by ASI (Agro Services International) and data were analyzed both statistically and geostatistically.Results showed that the contents of soil OM,NH4+,and Zn in Haifeng farm were very low for rice production and those of others were enough to meet the need for rice cultivation.The spatial distribution model and spatial dependence level for 13 soil chemical properties varied in the field.Soil Mg and B showed strong spatial variability on both descriptive statistics and geostatistics,and other properties showed moderate spatial variability.Themaximum ranges for K,Ca,Mg,S,Cu and Mn were all~3990.6m and the minimum ranges for soil pH,OM,NH4+,P,Fe,and Zn ranged from 516.7 to 1166.2 m.Clearpatchy distribution of N,P,K,Mg,S,B,Mn,and Zn were found from their spatial distribution maps.This proved that sampling strategy for estimating variability should be adapted to the different soil chemical properties and field management.Therefore,the spatial variability of soil chemical properties with strong spatial dependence could be readily managed and a site-specific fertilization scheme for precision farming could be easily developed.

  12. Physico-chemical properties and cytotoxic effects of sugar-based surfactants: Impact of structural variations.

    Science.gov (United States)

    Lu, Biao; Vayssade, Muriel; Miao, Yong; Chagnault, Vincent; Grand, Eric; Wadouachi, Anne; Postel, Denis; Drelich, Audrey; Egles, Christophe; Pezron, Isabelle

    2016-09-01

    Surfactants derived from the biorefinery process can present interesting surface-active properties, low cytotoxicity, high biocompatibility and biodegradability. They are therefore considered as potential sustainable substitutes to currently used petroleum-based surfactants. To better understand and anticipate their performances, structure-property relationships need to be carefully investigated. For this reason, we applied a multidisciplinary approach to systematically explore the effect of subtle structural variations on both physico-chemical properties and biological effects. Four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or maltose head group by an amide linkage, were synthesized and evaluated together along with two commercially available standard surfactants. Physico-chemical properties including solubility, Krafft point, surface-tension lowering and critical micellar concentration (CMC) in water and biological medium were explored. Cytotoxicity evaluation by measuring proliferation index and metabolic activity against dermal fibroblasts showed that all surfactants studied may induce cell death at low concentrations (below their CMC). Results revealed significant differences in both physico-chemical properties and cytotoxic effects depending on molecule structural features, such as the position of the linkage on the sugar head-group, or the orientation of the amide linkage. Furthermore, the cytotoxic response increased with the reduction of surfactant CMC. This study underscores the relevance of a methodical and multidisciplinary approach that enables the consideration of surfactant solution properties when applied to biological materials. Overall, our results will contribute to a better understanding of the concomitant impact of surfactant structure at physico-chemical and biological levels.

  13. Effects of Long-term Located Fertilization on the Physico-chemical Property of Soil Humus

    Institute of Scientific and Technical Information of China (English)

    SHI Ji-ping; ZHANG Fu-dao; LIN Bao

    2002-01-01

    A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red soil sampled from the Institute of Red Soil, Jinxian County, Jiangxi was conducted. The results showed that long-term fertilization had effects not only on the content and composition of soil humus, but also on the physico-chemical property of humus. With applying organic manure or combined application of organic manure and chemical fertilizer, E4 and E6 values of humic acid decreased in fluvo-aquic soil and arid red soil,but increased in paddy red soil. In paddy red soil, E4 and E6 values of humic acid increased also with a single application of chemical fertilizer, but E4 and E6 values had less change of humic acid in fluvo-aquic soil and arid red soil. The effects on the visible spectroscopic property of fulvic acid were different from that of humic acid. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase E4 and E6 values of fulvic acid in three types of soil. Single application of chemical fertilizer had less effect on the E4 and E6. Long-term fertilization could also influence the ultraviolet spectroscopic property of humus. With a single application of organic manure or combined application of organic manure and chemical fertilizer, the ultraviolet absorbance of humic acid and fulvic acid increased in the three types of soil.But this effect was obvious only in short wave length, and the effect could decrease if the wave length increased. With a single application of chemical fertilizer the ultraviolet absorbance of fulvic acid could increase, but it of humic acid increased only in fluvo-aquic soil. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase the content of total acidic groups, carboxy groups and

  14. Chemical composition and antidermatophytic properties of volatile fractions of hexanic extract from leaves of Cupressus lusitanica Mill. from Cameroon.

    Science.gov (United States)

    Kuiate, Jules-Roger; Bessière, Jean Marie; Zollo, Paul Henri Amvam; Kuate, Serge Philibert

    2006-01-16

    The chemical composition of five column fractions of hexanic leaf extract of Cupressus lusitanica were analysed by gas chromatography and gas chromatography-mass spectrometry and then tested for their antidermatophytic activities using the agar dilution method. The first fraction (F(1)) has only hydrocabon monoterpenes with alpha-pinene (80.0%) as major component. The main constituents of the second fraction (F(2)) were epi-bicyclosesquiphellandrene (35.3%), epi-zonarene (10.3%), 1S, cis-calamenene (13.1%) and beta-himachalene (10.4%). The third fraction (F(3)) was rich in hydrocarbon sesquiterpenes (45.4%) and a relatively high amount of diterpenes (29.8%) with epi-bicyclosesquiphellandrene (14.3%), pimaric acid (7.5%), kaurenoic acid (6.9%) and 8-beta-hydroxysandaracopimarane (3.5%) as main components. The last two fractions contain high molecular weight aliphatic hydrocarbons, their main constituents been eicosane (41.1%) and tricosane (37.3%) and heptacosane (22.1%). The agar dilution method was used to evaluate the antifungal properties of the crude extract and its fractions. These fractions showed several degrees of antidermatophytic activities against Microsporum audouinii, Microsporum Langeronii, Microsporum canis, Trichophyton rubrum and Trichophyton tonsurans. Fractions F(1) and F(3) exhibited the highest antidermatophytic activities with repective MICs of 250 and 125 mug/ml while the fractions F(4) and F(5) did not prevent the growth of the tested fungi up to dose 2,500 mug/ml.

  15. Estimation and Uncertainty Analysis of Flammability Properties of Chemicals using Group-Contribution Property Models

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Abildskov, Jens; Sin, Gürkan

    or time constraints, property prediction models like group contribution (GC) models can estimate flammability data. The estimation needs to be accurate, reliable and as less time consuming as possible. However, GC property prediction methods frequently lack rigorous uncertainty analysis. Hence......, there is no information about the reliability of the data. Furthermore, the global optimality of the GC parameters estimation is often not ensured. In this research project flammability-related property data, like LFL and UFL, are estimated using the Marrero and Gani group contribution method (MG method). In addition...... the group contribution in three levels: The contributions from a specific functional group (1st order parameters), from polyfunctional (2nd order parameters) as well as from structural groups (3rd order parameters). The latter two classes of GC factors provide additional structural information beside...

  16. Cedar leaf oil poisoning

    Science.gov (United States)

    Cedar leaf oil is made from some types of cedar trees. Cedar leaf oil poisoning occurs when someone swallows this substance. ... The substance in cedar leaf oil that can be harmful is thujone (a hydrocarbon).

  17. EFFECT OF THERMAL TREATMENT ON THE CHEMICAL COMPOSITION AND MECHANICAL PROPERTIES OF BIRCH AND ASPEN

    Directory of Open Access Journals (Sweden)

    Duygu Kocaefe

    2008-05-01

    Full Text Available The high temperature treatment of wood is one of the alternatives to chemical treatment. During this process, the wood is heated to higher temperatures than those of conventional drying. The wood structure changes due to decomposition of hemicelluloses, ramification of lignin, and crystallization of cellulose. The wood becomes less hygroscopic. These changes improve the dimensional stability of wood, increase its resistance to micro-organisms, darken its color, and modify its hardness. However, wood also might loose some of its elasticity. Consequently, the heat treatment conditions have to be optimized. Therefore, it is important to understand the transformation of the chemical structure of wood caused by the treatment. In this study, the modification of the surface composition of the wood was followed with Fourier transform infrared spectroscopy (FTIR and inverse gas chromatography (IGC under different experimental conditions. The effect of maximum treatment temperatures on the chemical composition of Canadian birch and aspen as well as the correlations between their chemical transformation and different mechanical properties are presented. FTIR analysis results showed that the heat treatment affected the chemical composition of birch more compared to that of aspen. The results of IGC tests illustrated that the surfaces of the aspen and birch became more basic with heat treatment. The mechanical properties were affected by degradation of hemicellulose, ramification of lignin and cellulose crystallization.

  18. Modelling physico-chemical properties of (benzo)triazoles, and screening for environmental partitioning.

    Science.gov (United States)

    Bhhatarai, B; Gramatica, P

    2011-01-01

    (Benzo)triazoles are distributed throughout the environment, mainly in water compartments, because of their wide use in industry where they are employed in pharmaceutical, agricultural and deicing products. They are hazardous chemicals that adversely affect humans and other non-target species, and are on the list of substances of very high concern (SVHC) in the new European regulation of chemicals - REACH (Registration, Evaluation, Authorization and Restriction of Chemical substances). Thus there is a vital need for further investigations to understand the behavior of these compounds in biota and the environment. In such a scenario, physico-chemical properties like aqueous solubility, hydrophobicity, vapor pressure and melting point can be useful. However, the limited availability and the high cost of lab testing prevents the acquisition of necessary experimental data that industry must submit for the registration of these chemicals. In such cases a preliminary analysis can be made using Quantitative Structure-Property Relationships (QSPR) models. For such an analysis, we propose Multiple Linear Regression (MLR) models based on theoretical molecular descriptors selected by Genetic Algorithm (GA). Training and prediction sets were prepared a priori by splitting the available experimental data, which were then used to derive statistically robust and predictive (both internally and externally) models. These models, after verification of their structural applicability domain (AD), were used to predict the properties of a total of 351 compounds, including those in the REACH preregistration list. Finally, Principal Component Analysis was applied to the predictions to rank the environmental partitioning properties (relevant for leaching and volatility) of new and untested (benzo)triazoles within the AD of each model. Our study using this approach highlighted compounds dangerous for the aquatic compartment. Similar analyses using predictions obtained by the EPI Suite and

  19. Chemical characterization and physico-chemical properties of aerosols at Villum Research Station, Greenland during spring 2015

    Science.gov (United States)

    Glasius, M.; Iversen, L. S.; Svendsen, S. B.; Hansen, A. M. K.; Nielsen, I. E.; Nøjgaard, J. K.; Zhang, H.; Goldstein, A. H.; Skov, H.; Massling, A.; Bilde, M.

    2015-12-01

    The effects of aerosols on the radiation balance and climate are of special concern in Arctic areas, which have experienced warming at twice the rate of the global average. As future scenarios include increased emissions of air pollution, including sulfate aerosols, from ship traffic and oil exploration in the Arctic, there is an urgent need to obtain the fundamental scientific knowledge to accurately assess the consequences of pollutants to environment and climate. In this work, we studied the chemistry of aerosols at the new Villum Research Station (81°36' N, 16°40' W) in north-east Greenland during the "inauguration campaign" in spring 2015. The chemical composition of sub-micrometer Arctic aerosols was investigated using a Soot Particle Time-of-Flight Aerosol Mass Spectrometer (SP-ToF-AMS). Aerosol samples were also collected on filters using both a high-volume sampler and a low-volume sampler equipped with a denuder for organic gases. Chemical analyses of filter samples include determination of inorganic anions and cations using ion-chromatography, and analysis of carboxylic acids and organosulfates of anthropogenic and biogenic origin using ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS). Previous studies found that organosulfates constitute a surprisingly high fraction of organic aerosols during the Arctic Haze period in winter and spring. Investigation of organic molecular tracers provides useful information on aerosol sources and atmospheric processes. The physico-chemical properties of Arctic aerosols are also under investigation. These measurements include particle number size distribution, water activity and surface tension of aerosol samples in order to deduct information on their hygroscopicity and cloud-forming potential. The results of this study are relevant to understanding aerosol sources and processes as well as climate effects in the Arctic, especially during the Arctic haze

  20. IR study on surface chemical properties of catalytic grown carbon nanotubes and nanofibers

    Institute of Scientific and Technical Information of China (English)

    Li-hua TENG; Tian-di TANG

    2008-01-01

    In this study, the surface chemical properties of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) grown by catalytic decomposition of methane on nickel and cobalt based catalysts were studied by DRIFT (Diffuse Reflectance Infrared Fourier Transform) and transmission Infrared (IR) spectroscopy. The results show that the surface exists not only carbon-hydrogen groups, but also carboxyl, ketene or quinone (carbonyl) oxygen-containing groups. These functional groups were formed in the process of the material growth, which result in large amount of chemical defect sites on the walls.

  1. Influence of La2O3 Additions on Chemical Durability and Dielectric Properties of Boroaluminosilicate Glasses

    Science.gov (United States)

    Zhang, X. H.; Yue, Y. L.; Wu, H. T.

    2012-12-01

    Boroaluminosilicate glasses containing La2O3 were prepared by the normal quenching method. The glass transition temperatures (Tg) were measured by differential scanning calorimetry (DSC). The structural role of RO was investigated by nuclear magnetic resonance (NMR). Chemical durability was evaluated by weight losses of glass samples after immersion in HC1 solution. High resolution scanning electron microscopy (HR-SEM) was used to examine the surface micrographs of corroded glass samples. The dielectric constant and tangent loss were measured in the frequency range 10-106 Hz. The results revealed that chemical durability and dielectric properties increased with increasing La2O3 content.

  2. The chemical composition and biological properties of coconut (Cocos nucifera L.) water.

    Science.gov (United States)

    Yong, Jean W H; Ge, Liya; Ng, Yan Fei; Tan, Swee Ngin

    2009-12-09

    Coconut water (coconut liquid endosperm), with its many applications, is one of the world's most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water.

  3. The preparation of low electroendosmosis agarose and its physico-chemical property

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength(1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.

  4. Leaf Collection Posting Log

    Data.gov (United States)

    Montgomery County of Maryland — This dataset contains leaf collection dates for area and subarea where leaf collection service is provided by Montgomery County Department of Transportation. Update...

  5. Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

    Directory of Open Access Journals (Sweden)

    Daniela Aparecida de Oliveira

    2014-10-01

    Full Text Available Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control, 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Vermelho distrófico (Hapludox soil. In the control, the quantities of P and K removed by harvested grains were replaced in the next crop cycle. Soil physical properties (bulk density, porosity, texture, and saturated hydraulic conductivity and chemical properties (organic matter, pH, extractable P, and exchangeable K were measured. Soil solution samples were collected at depths of 20, 40 and 80 cm using suction lysimeters, and glyphosate concentrations were measured over a 60-day period after slurry application. Soil physical and chemical properties were little affected by the pig slurry applications, but soil pH was reduced and P levels increased in the surface layers. In turn, K levels were increased in sub-surface layers. Glyphosate concentrations tended to decrease over time but were not affected by pig slurry application. The concentrations of glyphosate found in different depths show that the pratice of this application in agricultural soils has the potential for contamination of groundwater, especially when the water table is the surface and heavy rains occur immediately after application.

  6. Thermodynamic properties for applications in chemical industry via classical force fields.

    Science.gov (United States)

    Guevara-Carrion, Gabriela; Hasse, Hans; Vrabec, Jadran

    2012-01-01

    Thermodynamic properties of fluids are of key importance for the chemical industry. Presently, the fluid property models used in process design and optimization are mostly equations of state or G (E) models, which are parameterized using experimental data. Molecular modeling and simulation based on classical force fields is a promising alternative route, which in many cases reasonably complements the well established methods. This chapter gives an introduction to the state-of-the-art in this field regarding molecular models, simulation methods, and tools. Attention is given to the way modeling and simulation on the scale of molecular force fields interact with other scales, which is mainly by parameter inheritance. Parameters for molecular force fields are determined both bottom-up from quantum chemistry and top-down from experimental data. Commonly used functional forms for describing the intra- and intermolecular interactions are presented. Several approaches for ab initio to empirical force field parameterization are discussed. Some transferable force field families, which are frequently used in chemical engineering applications, are described. Furthermore, some examples of force fields that were parameterized for specific molecules are given. Molecular dynamics and Monte Carlo methods for the calculation of transport properties and vapor-liquid equilibria are introduced. Two case studies are presented. First, using liquid ammonia as an example, the capabilities of semi-empirical force fields, parameterized on the basis of quantum chemical information and experimental data, are discussed with respect to thermodynamic properties that are relevant for the chemical industry. Second, the ability of molecular simulation methods to describe accurately vapor-liquid equilibrium properties of binary mixtures containing CO(2) is shown.

  7. Deciphering chemical order/disorder and material properties at the single-atom level.

    Science.gov (United States)

    Yang, Yongsoo; Chen, Chien-Chun; Scott, M C; Ophus, Colin; Xu, Rui; Pryor, Alan; Wu, Li; Sun, Fan; Theis, Wolfgang; Zhou, Jihan; Eisenbach, Markus; Kent, Paul R C; Sabirianov, Renat F; Zeng, Hao; Ercius, Peter; Miao, Jianwei

    2017-02-01

    Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling 'real' materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily on average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. This work combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure-property relationships at the fundamental level.

  8. Deciphering chemical order/disorder and material properties at the single-atom level

    Science.gov (United States)

    Yang, Yongsoo; Chen, Chien-Chun; Scott, M. C.; Ophus, Colin; Xu, Rui; Pryor, Alan; Wu, Li; Sun, Fan; Theis, Wolfgang; Zhou, Jihan; Eisenbach, Markus; Kent, Paul R. C.; Sabirianov, Renat F.; Zeng, Hao; Ercius, Peter; Miao, Jianwei

    2017-02-01

    Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling ‘real’ materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily on average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. This work combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure–property relationships at the fundamental level.

  9. Influence of copper nanoparticles on the physical-chemical properties of activated sludge.

    Science.gov (United States)

    Chen, Hong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun; Li, Xiang

    2014-01-01

    The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS), play vital roles in the normal operation of wastewater treatment plants (WWTPs). The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on activated sludge. This paper focused on the effects of copper nanoparticles (CuNPs) on these specific physical-chemical properties of activated sludge. It was found that most of these properties were unaffected by the exposure to lower CuNPs concentration (5 ppm), but different observation were made at higher CuNPs concentrations (30 and 50 ppm). At the higher CuNPs concentrations, the sludge surface charge increased and the hydrophobicity decreased, which were attributed to more Cu2+ ions released from the CuNPs. The carbohydrate content of EPS was enhanced to defense the toxicity of CuNPs. The flocculating ability was found to be deteriorated due to the increased cell surface charge, the decreased hydrophobicity, and the damaged cell membrane. The worsened flocculating ability made the sludge flocs more dispersed, which further increased the toxicity of the CuNPs by increasing the availability of the CuNPs to the bacteria present in the sludge. Further investigation indicated that the phosphorus removal efficiency decreased at higher CuNPs concentrations, which was consistent with the deteriorated physical-chemical properties of activated sludge. It seems that the physical-chemical properties can be used as an indicator for determining CuNPs toxicity to the bacteria in activated sludge. This work is important because bacteria toxicity effects to the activated sludge caused by nanoparticles may lead to the deteriorated treatment efficiency of wastewater treatment, and it is therefore necessary to find an easy way to indicate this toxicity.

  10. "Breath figures" on leaf surfaces-formation and effects of microscopic leaf wetness.

    Science.gov (United States)

    Burkhardt, Juergen; Hunsche, Mauricio

    2013-01-01

    "Microscopic leaf wetness" means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  11. ‘Breath figures’ on leaf surfaces – formation and effects of microscopic leaf wetness

    Directory of Open Access Journals (Sweden)

    Jürgen eBurkhardt

    2013-10-01

    Full Text Available ‘Microscopic leaf wetness’ means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 µm, microscopic leaf wetness it is about 2 orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the amount and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g. ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  12. Physico-chemical properties of Brazilian cocoa butter and industrial blends. Part I Chemical composition, solid fat content and consistency

    Directory of Open Access Journals (Sweden)

    Ribeiro, A. P. B.

    2012-03-01

    Full Text Available A comparative study of the primary properties of six cocoa butter samples, representative of industrial blends and cocoa butter extracted from fruits cultivated in different geographical areas in Brazil is presented. The samples were evaluated according to fatty acid composition, triacylglycerol composition, regiospecific distribution, melting point, solid fat content and consistency. The results allowed for differentiating the samples according to their chemical compositions, thermal resistance properties, hardness characteristics, as well as technological adequacies and potential use in regions with tropical climates.

    En este trabajo se presenta un estudio comparativo de las propiedades primarias de mantecas de cacao, representativas de las mezclas industriales, y de la manteca de cacao original de diferentes zonas geográficas de Brasil. Las muestras fueron evaluadas de acuerdo a la composición de ácidos grasos, composición de triglicéridos, distribución de los ácidos grasos en las moléculas de triglicéridos, punto de fusión, contenido de grasa sólida y consistencia. Los resultados permitieron diferenciar las muestras por su composición química, propiedades de resistencia térmica, características de dureza, así como en materia de adecuaciones tecnológicas y los usos potenciales en las regiones de clima tropical.

  13. Factors Affecting Leaf Selection by Foregut-fermenting Proboscis Monkeys: New Insight from in vitro Digestibility and Toughness of Leaves.

    Science.gov (United States)

    Matsuda, Ikki; Clauss, Marcus; Tuuga, Augustine; Sugau, John; Hanya, Goro; Yumoto, Takakazu; Bernard, Henry; Hummel, Jürgen

    2017-02-17

    Free-living animals must make dietary choices in terms of chemical and physical properties, depending on their digestive physiology and availability of food resources. Here we comprehensively evaluated the dietary choices of proboscis monkeys (Nasalis larvatus) consuming young leaves. We analysed the data for leaf toughness and digestibility measured by an in vitro gas production method, in addition to previously reported data on nutrient composition. Leaf toughness, in general, negatively correlated with the crude protein content, one of the most important nutritional factors affecting food selection by leaf-eating primates. This result suggests that leaf toughness assessed by oral sensation might be a proximate cue for its protein content. We confirmed the importance of the leaf chemical properties in terms of preference shown by N. larvatus; leaves with high protein content and low neutral detergent fibre levels were preferred to those of the common plant species. We also found that these preferred leaves were less tough and more digestible than the alternatives. Our in vitro results also suggested that N. larvatus were little affected by secondary plant compounds. However, the spatial distribution pattern of plant species was the strongest factor explaining the selection of the preferred leaf species.

  14. Factors Affecting Leaf Selection by Foregut-fermenting Proboscis Monkeys: New Insight from in vitro Digestibility and Toughness of Leaves

    Science.gov (United States)

    Matsuda, Ikki; Clauss, Marcus; Tuuga, Augustine; Sugau, John; Hanya, Goro; Yumoto, Takakazu; Bernard, Henry; Hummel, Jürgen

    2017-01-01

    Free-living animals must make dietary choices in terms of chemical and physical properties, depending on their digestive physiology and availability of food resources. Here we comprehensively evaluated the dietary choices of proboscis monkeys (Nasalis larvatus) consuming young leaves. We analysed the data for leaf toughness and digestibility measured by an in vitro gas production method, in addition to previously reported data on nutrient composition. Leaf toughness, in general, negatively correlated with the crude protein content, one of the most important nutritional factors affecting food selection by leaf-eating primates. This result suggests that leaf toughness assessed by oral sensation might be a proximate cue for its protein content. We confirmed the importance of the leaf chemical properties in terms of preference shown by N. larvatus; leaves with high protein content and low neutral detergent fibre levels were preferred to those of the common plant species. We also found that these preferred leaves were less tough and more digestible than the alternatives. Our in vitro results also suggested that N. larvatus were little affected by secondary plant compounds. However, the spatial distribution pattern of plant species was the strongest factor explaining the selection of the preferred leaf species. PMID:28211530

  15. Breakdown of Leaf Litter in a Neotropical Stream

    OpenAIRE

    Mathuriau, Catherine; Chauvet, Eric

    2002-01-01

    International audience; We investigated the breakdown of 2 leaf species, Croton gossypifolius (Euphorbiaceae) and Clidemia sp. (Melastomataceae), in a 4th-order neotropical stream (Andean Mountains, southwestern Colombia) using leaf bags over a 6-wk period. We determined the initial leaf chemical composition and followed the change in content of organic matter, C, N, and ergosterol, the sporulation activity of aquatic hyphomy cetes, and the structure and composition of leaf-associated aquatic...

  16. Predicting physico-chemical properties of polychlorinated diphenyl ethers (PCDEs):potential persistent organic pollutants (POPs)

    Institute of Scientific and Technical Information of China (English)

    HUANG Jun; YU Gang; YANG Xi; ZHANG Zu-lin

    2004-01-01

    Polychlorinated diphenyl ethers(PCDEs) have received more and more concerns as a category of potentialpersistent organic pollutants( POPs). Modeling its environmental fate and exposure assessment require a number offundamental physico-chemical properties. However, the experimental data are currently limited due to the difficulty inanalysis caused by the complexity of PCDE congeners. As an alternative, the quantitative structure propertyrelationship(QSPR) approach could be used. In this paper, twelve kinds of molecular connectivity indices(MCIs) ofall 209 possible molecular structure patterns of PCDEs were calculated. Based on 106 PCDEs with three observedphysico-chemical properties-vapour pressure(PoL), aqueous solubility(Sw) and n-octanol/water(Kow) and theirMCIs data, a series of QSPR equations were established using multiple linear regression(MLR) method. As aresult, three equations with best performance were selected mainly from the view of high regression coefficient(R)and low standard error( SE). All of them showed significant relationship and high accuracy. With these equationsthe properties of other 103 patterns of PCDEs without the reported observed values were predicted. Furthermore,three partition properties for PCDE congeners-Henry' s Law constants(H), partition coefficients between gas/water(Kgw) and gas/n-octanol ( Kgo ) were calculated according to the internal relationship among these six properties.These observed and predicted values, in contrast with the criteria listed in the Stockholm treaty about POPs whichhas been signed by more than ninety countries in May 2001, illustrated that most of PCDEs congeners are potentialpersistent organic pollutants. As all descriptors/predictors are derived just from the molecular structure itself andwithout the import of any empirical parameters, this method is impersonal and promising for the estimation ofphysico-chemical properties of PCDEs.

  17. The influence of chemical composition on the properties and structure Al-Si-Cu(Mg alloys

    Directory of Open Access Journals (Sweden)

    M. Kaczorowski

    2007-04-01

    Full Text Available The mechanical properties of different chemical composition AlSiCuMg type cast alloys after precipitation hardening are presented. The aim of the study was to find out how much the changes in chemistry of aluminum cast alloys permissible by EN-PN standards may influence the mechanical properties of these alloys. Eight AlSi5Cu3(Mg type cast alloys of different content alloying elements were selected for the study. The specimens cut form test castings were subjected to precipitation hardening heat treatment. The age hardened specimens were evaluated using tensile test, hardness measurements and impact test. Moreover, the structure investigation were carried out using either conventional light Metallography and scanning (SEM and transmission (TEM electron microscopy. The two last methods were used for fractography observations and precipitation process observations respectively. It was concluded that the changes in chemical composition which can reach even 2,5wt.% cause essential differences of the structure and mechanical properties of the alloys. As followed from quantitative evaluation and as could be predicted theoretically, copper and silicon mostly influenced the mechanical properties of AlSi5Cu3(Mg type cast alloys. Moreover it was showed that the total concentration of alloying elements accelerated and intensifies the process of decomposition of supersaturated solid solution. The increase of Cu and Mg concentration increased the density of precipitates. It increases of strength properties of the alloys which are accompanied with decreasing in ductility.

  18. Hard-to-recover oils with anomalous physical and chemical properties

    Science.gov (United States)

    Yashchenko, I. G.; Polishchuk, Y. M.

    2016-11-01

    Using the global database on physical and chemical properties of oils, the analysis of distribution of viscous, heavy, waxy and highly resinous oils in terms of volumes of their reserves was carried out. It is known that heavy and viscous oils account for slightly more than 33% of the total sample. Resinous and paraffin oils account for less than 30% of the total sample. The criteria necessary to classify oils as hard-to-recover oil reserves are determined. Features of physicochemical properties of these oils are studied under various conditions. The results obtained could be used to solve practical issues in the oil sector.

  19. Electronic absorption spectra and nonlinear optical properties of CO2 molecular aggregates: A quantum chemical study

    Indian Academy of Sciences (India)

    Tarun K Mandal; Sudipta Dutta; Swapan K Pati

    2009-09-01

    We have investigated the structural aspects of several carbon dioxide molecular aggregates and their spectroscopic and nonlinear optical properties within the quantum chemical theory framework. We find that, although the single carbon dioxide molecule prefers to be in a linear geometry, the puckering of angles occur in oligomers because of the intermolecular interactions. The resulting dipole moments reflect in the electronic excitation spectra of the molecular assemblies. The observation of significant nonlinear optical properties suggests the potential application of the dense carbon dioxide phases in opto-electronic devices.

  20. Molecular design chemical structure generation from the properties of pure organic compounds

    CERN Document Server

    Horvath, AL

    1992-01-01

    This book is a systematic presentation of the methods that have been developed for the interpretation of molecular modeling to the design of new chemicals. The main feature of the compilation is the co-ordination of the various scientific disciplines required for the generation of new compounds. The five chapters deal with such areas as structure and properties of organic compounds, relationships between structure and properties, and models for structure generation. The subject is covered in sufficient depth to provide readers with the necessary background to understand the modeling

  1. Chemical structure and physical properties of radiation-induced crosslinking of polytetrafluoroethylene

    Energy Technology Data Exchange (ETDEWEB)

    Oshima, Akihiro E-mail: aks@taka.jaeri.go.jp; Ikeda, Shigetoshi; Katoh, Etsuko; Tabata, Yoneho

    2001-07-01

    The chemical structure and physical properties of polytetrafluoroethylene (PTFE) that has been crosslinked by radiation have been studied by various methods. It has been found that a Y-type crosslinking structure and a Y-type structure incorporating a double bond (modified Y-type) is formed in PTFE by radiation-crosslinking in the molten state. In addition, various types of double bond structures, excluding the crosslinking site, have been identified. The crosslinked PTFE has a good light transparency due to the loss of crystallites, whilst it retains the excellent properties of electrical insulation and heat resistance. The coefficient of abrasion and the permanent creep are also greatly improved by crosslinking.

  2. Unique magnetic and thermoelectric properties of chemically functionalized narrow carbon polymers

    Science.gov (United States)

    Zberecki, K.; Wierzbicki, M.; Swirkowicz, R.; Barnaś, J.

    2017-02-01

    We analyze magnetic, transport and thermoelectric properties of narrow carbon polymers, which are chemically functionalized with nitroxide groups. Numerical calculations of the electronic band structure and the corresponding transmission function are based on density functional theory. Transport and thermoelectric parameters are calculated in the linear response regime, with particular interest in charge and spin thermopowers (charge and spin Seebeck effects). Such nanoribbons are shown to have thermoelectric properties described by large thermoelectric efficiency, which makes these materials promising from the application point of view.

  3. Studies on chemical bath deposited zinc sulphide thin films with special optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Ladar, Maria [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); ' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Popovici, Elisabeth-Jeanne [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania)]. E-mail: jennypopovici@yahoo.com; Baldea, Ioan [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); Grecu, Rodica [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Indrea, Emil [National Institute for R and D of Isotopic and Molecular Technology, Donath 71-103, 400293 Cluj-Napoca (Romania)

    2007-05-31

    Adherent and uniform zinc sulphide thin films were deposited on optical glass platelets from chemical bath containing thiourea, zinc acetate, ammonia and sodium citrate. The samples, as they were prepared were investigated by UV-vis absorption/reflection spectroscopy, fluorescence spectroscopy and X-ray diffraction. The effects of growth conditions such as reagent concentration and deposition technique (mono- and multi-layer) on optical and structural properties of the ZnS thin films have been studied. The ability of ZnS films to exhibit luminescent properties has also been investigated.

  4. Chemical and texture characteristics and sensory properties of “mozzarella” cheese from different feeding systems

    Directory of Open Access Journals (Sweden)

    R. Rubino

    2010-02-01

    Full Text Available The aim of this study was describing the chemical composition, the rheological characteristics and the sensory properties of “mozzarella” cheese produced with milk from buffalos fed with different diets. The study involved two farms and four feeding systems. In farm C, one group was mostly fed with Ryegrass Hay (RH and the other group with Ryegrass Silage (RS. In farm T, instead, one group was mostly fed with Corn Silage (CS and the other one with a Sorghum Silage (SS. In summer, three cheesemakings, for each farm and for each feeding system, were carried out at C.R.A. of Bella. In each farm, data were processed by the analysis of variance in order to compare the effects of two feeding systems. Some parameters of chemical and texture characteristics and sensory properties were influenced by the feeding system. Results were remarkable for the DOP products.

  5. IMPROVEMENTS IN WOOD THERMOPLASTIC MATRIX COMPOSITE MATERIALS PROPERTIES BY PHYSICAL AND CHEMICAL TREATMENTS

    Directory of Open Access Journals (Sweden)

    Irena Zivkovic

    2016-03-01

    Full Text Available This paper presents a short overview of the developments made in the field of wood thermoplastic composites in terms of surface treatment, flammability, matrix/reinforcement model, properties and application of recycled polymer matrices. The usage of lignocellulosic fibers as reinforcement in composite materials demands well formed interface between the fiber and the matrix. Because of the different nature of reinforcement and matrix components some physical and chemical treatment methods which improve the fiber matrix adhesion were introduced, as well as the improvements of lignocellulosic fibers and thermoplastic polymer matrix based composites flammability characteristics. These physical and chemical treatments influence the hydrophilic character of the lignocellulosic fibers, and therefore change their physical and mechanical properties.

  6. Structural, Mechanical and Optical Properties of Plasma-chemical Si-C-N Films

    Directory of Open Access Journals (Sweden)

    A.O. Kozak

    2014-11-01

    Full Text Available An influence of the substrate temperature in the range of 40-400 °C on the properties of the Si-C-N films deposited by plasma enhanced chemical vapor deposition (PECVD technique using hexamethyldisilazane is analyzed. Study of the structure, chemical bonding, surface morphology, mechanical properties and energy gap of the obtained films was carried out using X-ray diffraction, infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, optical measurements and nanoindentation. It was established that all the films were X-ray amorphous and had low surface roughness. Intensive hydrogen effusion from the films takes place, when substrate temperature increases up to 400 °C, which promotes a decrease of roughness and an increase in hardness and Young modules more than twice.

  7. Physical and chemical properties of olive oil extracted from olive cultivars grown in Shiraz and Kazeroon

    DEFF Research Database (Denmark)

    Homapour, M.; Hamedi, M.; Moslehishad, M.

    2014-01-01

    Background and objective: The composition of olive oil is significantly affected by the cultivar and climatic conditions. The present study determined the chemical characteristics of olive oil extracted from two major Iranian varieties of olive (yellow and local oil-grade) in Shiraz and Kazeroon......, two major olive-producing areas in Fars province. Materials and methods: The composition of olive oil is significantly affected by the cultivar and climatic conditions. The present study determined the chemical characteristics of olive oil extracted from two major Iranian varieties of olive (yellow...... and local oil-grade) in Shiraz and Kazeroon, two major olive-producing areas in Fars province. Results: The results showed that the physical and chemical properties of both cultivars are in accordance with national and international standards. There was a significant difference in acidity, iodine content...

  8. Chemical and Physical Properties of the Remote Marine Aerosol by Gravimetric and Electron Microscopic Methods.

    Science.gov (United States)

    McInnes, Lynn Mari

    The chemical and physical properties of the individual submicrometer particles in the remote marine boundary layer (MBL) atmosphere are important parameters used to study atmospheric processes. Particles in this size range influence the total number concentration of particles, the number concentration of cloud condensation nuclei, and the total light scattering. As the aerosol evolves by physical and chemical mechanisms, the aerosol properties will also change. It is therefore important to measure the changing aerosol properties as a function of individual particle size within the meteorologically important time periods. Individual particle analysis using electron microscopy (EM) techniques coupled with X ray analysis can provide chemical, morphological, and particle size information on samples collected for only a few minutes. It is also possible to determine the ambient particle size distribution and relative abundances from the EM analysis using correction techniques. Measurements obtained from aerosol particles collected from the remote (MBL) during the Pacific Sulfur Stratus Investigation (PSI-3) and Cloud and Aerosol Chemistry Experiment (CACHE-1) at Cheeka Peak in the spring of 1991 and 1993 are presented along with results obtained from aerosol particles collected during the Marine Aerosol and Gas Exchange (MAGE) Experiment in the Equatorial Pacific and Radiatively Important Trace Species (RITS) Experiment in the spring of 1992 and 1993. Measurements of relative abundance of sea-salt, sulfate, and carbon-containing particles are presented as well as their chemistry. In particular the chemical reactions involving sea-salt particles are discussed in relation to the measurements of chloride depletion and sulfur enriched reported for individual particles. To supplement the few available measurements of the total submicrometer aerosol mass, samples were also collected for gravimetric analysis. Comparisons of the gravimetric mass to the total aerosol mass

  9. Processing of poly(lactic acid): characterization of chemical structure, thermal stability and mechanical properties

    OpenAIRE

    Carrasco Alonso, Félix Ángel; Pagès Figueras, Pere; Gamez Pérez, José; Santana Pérez, Orlando Onofre; Maspoch Rulduà, Mª Lluïsa

    2010-01-01

    The processing of poly(lactic acid) (injection and extrusion/injection) as well as annealing of processed materials were studied in order to analyze the variation of its chemical structure, thermal degradation and mechanical properties. Processing of PLA was responsible for a decrease in molecular weight, as determined by GPC, due to chain scission. The degree of crystallinity was evaluated by means of differential scanning calorimetry and X-ray diffraction. It was found that mech...

  10. Principal Chemical Properties of Artificial Soil Composed of Fly Ash and Furfural Residue

    Institute of Scientific and Technical Information of China (English)

    FENG Yong-Jun; LI Fen; WANG Xiao-Ling; LIU Xi-Min; ZHANG Lei-Na

    2006-01-01

    To solve soil shortage in reclaiming subsided land of coal mines, the principal chemical properties of artificial soil formed by mixing organic furfural residue and inorganic fly ash were examined. The results indicated that the artificial soil was suitable for agriculture use after irrigation and desalination, the available nutrients in the artificial soil could satisfy the growth demand of plants, and the pH tended to the neutrality.

  11. Structure and physico-chemical properties in mixed aqueoussolution of sodium alkylcarboxylate-alkyltrimethylammoniumbromide

    Institute of Scientific and Technical Information of China (English)

    HUANG, Jian-Bin(黄建滨); ZHAO, Guo-Xi(赵国玺); HE, Xu(何煦); ZHU, Bu-Yao(朱步瑶); FU, Hong-Lan(付宏兰)

    2000-01-01

    The physico-chemical properties of organized assemblies (micelle or vesicle) from sodium alkylcarboxylate-alkyltrimethyl-ammonium bromide mixture have been investigated systematically. In different mixed cationic-anionic surfactant systems, micelles and vesicles can coexist or be transformed into each other on different conditions. The experimental results are explained prelimilarily from the viewpoint of molecular packing geometry. The solubilization of organic compound in the mixed surfactant system was also studied in detail.

  12. Influence of Storage Conditions on Geotechnical Properties of Ariake Clay and on its Chemical Stabilization

    OpenAIRE

    シナ, コスラナント; SINAT, KOSLANANT

    2006-01-01

    Influence of storage conditions on geotechnical properties of Ariake clay and on its chemical stabilization is investigated to make use of the surplus clay as construction materials. The influence factors in lime and cement stabilization including salts, diatom and clay minerals were studied. The experiments were set up by mixing clays with various proportions of studied factors. As a result, for Bangkok clay, Kaolin and Bentonite, the factors improving the unconfined compressive strength of...

  13. Physical and Chemical Properties of Some Imported Woods and their Degradation by Termites

    OpenAIRE

    Shanbhag, Rashmi R.; Sundararaj, R.

    2013-01-01

    The influence of physical and chemical properties of 20 species of imported wood on degradation of the wood by termites under field conditions was studied. The wood species studied were: Sycamore maple, Acer pseudoplatanus L. (Sapindales: Sapindaceae) (from two countries), Camphor, Dryobalanops aromatic C.F.Gaertner (Malvales: Dipterocarpaceae), Beech, Fagus grandifolia Ehrhart (Fagales: Fagaceae), F. sylvatica L. (from two countries), Oak, Quercus robur L., Ash, Fraxinus angustifolia Vahl (L...

  14. Properties and Performances of High Purity Corundum Bricks for Chemical and Petrochemical Industries in China

    Institute of Scientific and Technical Information of China (English)

    CHENRen-pin; LINYu-lian; 等

    1995-01-01

    The properties and performances of high purity corundum bricks for the refractory linings of the gasifiers in the ammonia and ethene synthesis and carbon black reaction furnaces in China are described.The high purity corundum bricks are characterized by high refractoriness,hot strength,dimensional stability and chemical inertness at elevated temperature,Their performances in the gasifiers and carbon black furnaces are very satisfied ,The failure mechansims of the refractory lining are discussed on the basis of the petrographic analysis.

  15. Analysis of the relationship between the structure and aromatic properties of chemical compounds.

    Science.gov (United States)

    Debska, Barbara; Guzowska-Swider, Barbara

    2003-04-01

    This paper presents the results of research on the relationship between the structure and odour properties of a selection of chemical compounds. The research concerns five groups of esters, each with a different smell: almond, apricot, apple, pineapple and rose. The supposed relationship between the smell and certain selected attributes of each molecule was examined by various pattern recognition techniques using programs developed in the Department of Computer Chemistry at Rzeszów University of Technology.

  16. Physico-Chemical Properties, Antioxidant Activity and Mineral Contents of Pineapple Genotypes Grown in China

    OpenAIRE

    Xin-Hua Lu; De-Quan Sun; Qing-Song Wu; Sheng-Hui Liu; Guang-Ming Sun

    2014-01-01

    The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/...

  17. Chemical and physical properties of poly (vinyl alcohol) hydrogel films formed by irradiation

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Chemical and physical properties of poly(vinyl alcohol)(PVA) hydrogel films were investigated as a function of production factors.The experimental results show that the gel fraction dependsstrongly on the radiation dose, the degree of swelling is inverselydependent on the concentration of PVA solution, the tensile strengthdepends mainly on the PVA blending ratio and the elongation at breakis inversely dependent on the radiation dose.

  18. Relationships between chemical structure, mechanical properties and materials processing in nanopatterned organosilicate fins

    Directory of Open Access Journals (Sweden)

    Gheorghe Stan

    2017-04-01

    Full Text Available The exploitation of nanoscale size effects to create new nanostructured materials necessitates the development of an understanding of relationships between molecular structure, physical properties and material processing at the nanoscale. Numerous metrologies capable of thermal, mechanical, and electrical characterization at the nanoscale have been demonstrated over the past two decades. However, the ability to perform nanoscale molecular/chemical structure characterization has only been recently demonstrated with the advent of atomic-force-microscopy-based infrared spectroscopy (AFM-IR and related techniques. Therefore, we have combined measurements of chemical structures with AFM-IR and of mechanical properties with contact resonance AFM (CR-AFM to investigate the fabrication of 20–500 nm wide fin structures in a nanoporous organosilicate material. We show that by combining these two techniques, one can clearly observe variations of chemical structure and mechanical properties that correlate with the fabrication process and the feature size of the organosilicate fins. Specifically, we have observed an inverse correlation between the concentration of terminal organic groups and the stiffness of nanopatterned organosilicate fins. The selective removal of the organic component during etching results in a stiffness increase and reinsertion via chemical silylation results in a stiffness decrease. Examination of this effect as a function of fin width indicates that the loss of terminal organic groups and stiffness increase occur primarily at the exposed surfaces of the fins over a length scale of 10–20 nm. While the observed structure–property relationships are specific to organosilicates, we believe the combined demonstration of AFM-IR with CR-AFM should pave the way for a similar nanoscale characterization of other materials where the understanding of such relationships is essential.

  19. Constitutive Relations for Reactive Transport Modeling: Effects of Chemical Reactions on Multi-Phase Flow Properties

    Science.gov (United States)

    Zhang, S.; Liu, H. H.; van Dijke, M. I.; Geiger, S.; Agar, S. M.

    2016-12-01

    The relationship between flow properties and chemical reactions is key to modeling subsurface reactive transport. This study develops closed-form equations to describe the effects of mineral precipitation and dissolution on multiphase flow properties (capillary pressure and relative permeabilities) of porous media. The model accounts for the fact that precipitation/dissolution only takes place in the water-filled part of pore space. The capillary tube concept was used to connect pore-scale changes to macroscopic hydraulic properties. Precipitation/dissolution induces changes in the pore radii of water-filled pores and consequently in the pore-size distribution. The updated pore-size distribution is converted back to a new capillary pressure-water saturation relation from which the new relative permeabilities are calculated. Pore network modeling is conducted on a Berea sandstone to validate the new continuum-scale relations. The pore network modeling results are satisfactorily predicted by the new closed-form equations. Currently the effects of chemical reactions on flow properties are represented as a relation between permeability and porosity in reactive transport modeling. Porosity is updated after chemical calculations from the change of mineral volumes, then permeability change is calculated from the porosity change using an empirical permeability-porosity relation, most commonly the Carman-Kozeny relation, or the Verma-Pruess relation. To the best of our knowledge, there are no closed-form relations available yet for the effects of chemical reactions on multi-phase flow properties, and thus currently these effects cannot be accounted for in reactive transport modeling. This work presents new constitutive relations to represent how chemical reactions affect multi-phase flow properties on the continuum scale based on the conceptual model of parallel capillary tubes. The parameters in our new relations are either pre-existing input in a multi-phase flow

  20. African peppermint (Mentha piperita) from Morocco: Chemical composition and antimicrobial properties of essential oil.

    Science.gov (United States)

    Marwa, Chraibi; Fikri-Benbrahim, Kawtar; Ou-Yahia, Douae; Farah, Abdellah

    2017-01-01

    To replace and avoid synthetic chemicals toxicity, there is a growing interest in the investigation of natural products from plant origin for the discovery of active compounds with antimicrobial properties. This work was devoted to determine chemical composition and antimicrobial properties of the EO of M. piperita harvested in the garden of the National Institute of Medicinal and Aromatic Plants of Morocco. Experiments have been conducted at the Microbial Biotechnology Laboratory at the Sciences and Technology Faculty, Sidi Mohamed Ben Abdellah University, Fez, Morocco. M. piperita oil was screened for its antimicrobial activity against seven bacteria and two fungi using broth microdilution method. Chemical EO analysis was performed using CPG/MS. The EO revealed menthol (46.32%), menthofuran (13.18%), menthyl acetate (12.10%), menthone (7.42%), and 1,8-cineole (6.06%) as the main constituents. The tested EO exhibited strong inhibitory effect against all tested microorganisms with minimum inhibitory concentrations ranging from 0.062% to 0.5% (v/v), except for Pseudomonas aeruginosa that was the least sensitive and was only inhibited by concentrations as high as 0.5% (v/v). The studied EO showed an antimicrobial potential. This reinforces its use as an alternative to chemical additives that can be applied to the food and drug industry.