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Littérature scientifique sur le sujet « BSOA »

Auteur : Grafiati
Publié le 1 avril 2023

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Articles de revues sur le sujet "BSOA"

1

Mentel, Th F., E. Kleist, S. Andres, M. Dal Maso, T. Hohaus, A. Kiendler-Scharr, Y. Rudich et al. « Secondary aerosol formation from stress-induced biogenic emissions and possible climate feedbacks ». Atmospheric Chemistry and Physics 13, no 17 (3 septembre 2013) : 8755–70. http://dx.doi.org/10.5194/acp-13-8755-2013.

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Abstract. Atmospheric aerosols impact climate by scattering and absorbing solar radiation and by acting as ice and cloud condensation nuclei. Biogenic secondary organic aerosols (BSOAs) comprise an important component of atmospheric aerosols. Biogenic volatile organic compounds (BVOCs) emitted by vegetation are the source of BSOAs. Pathogens and insect attacks, heat waves and droughts can induce stress to plants that may impact their BVOC emissions, and hence the yield and type of formed BSOAs, and possibly their climatic effects. This raises questions of whether stress-induced changes in BSOA formation may attenuate or amplify effects of climate change. In this study we assess the potential impact of stress-induced BVOC emissions on BSOA formation for tree species typical for mixed deciduous and Boreal Eurasian forests. We studied the photochemical BSOA formation for plants infested by aphids in a laboratory setup under well-controlled conditions and applied in addition heat and drought stress. The results indicate that stress conditions substantially modify BSOA formation and yield. Stress-induced emissions of sesquiterpenes, methyl salicylate, and C17-BVOCs increase BSOA yields. Mixtures including these compounds exhibit BSOA yields between 17 and 33%, significantly higher than mixtures containing mainly monoterpenes (4–6% yield). Green leaf volatiles suppress SOA formation, presumably by scavenging OH, similar to isoprene. By classifying emission types, stressors and BSOA formation potential, we discuss possible climatic feedbacks regarding aerosol effects. We conclude that stress situations for plants due to climate change should be considered in climate–vegetation feedback mechanisms.
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Lee, Alex K. Y., Jonathan P. D. Abbatt, W. Richard Leaitch, Shao-Meng Li, Steve J. Sjostedt, Jeremy J. B. Wentzell, John Liggio et Anne Marie Macdonald. « Substantial secondary organic aerosol formation in a coniferous forest : observations of both day- and nighttime chemistry ». Atmospheric Chemistry and Physics 16, no 11 (3 juin 2016) : 6721–33. http://dx.doi.org/10.5194/acp-16-6721-2016.

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Abstract. Substantial biogenic secondary organic aerosol (BSOA) formation was investigated in a coniferous forest mountain region in Whistler, British Columbia. A largely biogenic aerosol growth episode was observed, providing a unique opportunity to investigate BSOA formation chemistry in a forested environment with limited influence from anthropogenic emissions. Positive matrix factorization of aerosol mass spectrometry (AMS) measurement identified two types of BSOA (BSOA-1 and BSOA-2), which were primarily generated by gas-phase oxidation of monoterpenes and perhaps sesquiterpenes. The temporal variations of BSOA-1 and BSOA-2 can be explained by gas–particle partitioning in response to ambient temperature and the relative importance of different oxidation mechanisms between day and night. While BSOA-1 arises from gas-phase ozonolysis and nitrate radical chemistry at night, BSOA-2 is likely less volatile than BSOA-1 and consists of products formed via gas-phase oxidation by OH radical and ozone during the day. Organic nitrates produced through nitrate radical chemistry can account for 22–33 % of BSOA-1 mass at night. The mass spectra of BSOA-1 and BSOA-2 have higher values of the mass fraction of m/z 91 (f91) compared to the background organic aerosol. Using f91 to evaluate BSOA formation pathways in this unpolluted, forested region, heterogeneous oxidation of BSOA-1 is a minor production pathway of BSOA-2.
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Lee, A. K. Y., J. P. D. Abbatt, W. R. Leaitch, S. M. Li, S. J. Sjostedt, J. J. B. Wentzell, J. Liggio et A. M. Macdonald. « Substantial secondary organic aerosol formation in a coniferous forest : observations of both day and night time chemistry ». Atmospheric Chemistry and Physics Discussions 15, no 20 (16 octobre 2015) : 28005–35. http://dx.doi.org/10.5194/acpd-15-28005-2015.

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Abstract. Substantial biogenic secondary organic aerosol (BSOA) formation was investigated in a coniferous forest mountain region at Whistler, British Columbia. A largely biogenic aerosol growth episode was observed, providing a unique opportunity to investigate BSOA formation chemistry in a forested environment with limited influence from anthropogenic emissions. Positive matrix factorization of aerosol mass spectrometry (AMS) measurement identified two types of BSOA (BSOA-1 and BSOA-2), which were primarily generated by gas-phase oxidation of monoterpenes and perhaps sesquiterpenes. The temporal variations of BSOA-1 and BSOA-2 can be explained by gas-particle partitioning in response to ambient temperature and the relative importance of different oxidation mechanisms between day and night. While BSOA-1 will arise from gas-phase ozonolysis and nitrate radical chemistry at night, BSOA-2 is less volatile than BSOA-1 and consists of products formed via gas-phase oxidation by the OH radical and ozone during the day. Organic nitrates produced through nitrate radical chemistry can account for 22–33 % of BSOA-1 mass at night. The mass spectra of BSOA-1 and BSOA-2 have higher values of the mass fraction of m/z 91 (f91) compared to the background organic aerosol, and so f91 is used as an indicator of BSOA formation pathways. A comparison between laboratory studies in the literature and our field observations highlights the potential importance of gas-phase formation chemistry of BSOA-2 type materials that may not be captured in smog chamber experiments, perhaps due to the wall loss of gas-phase intermediate products.
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Zhang, Yu-Qing, Duo-Hong Chen, Xiang Ding, Jun Li, Tao Zhang, Jun-Qi Wang, Qian Cheng et al. « Impact of anthropogenic emissions on biogenic secondary organic aerosol : observation in the Pearl River Delta, southern China ». Atmospheric Chemistry and Physics 19, no 22 (28 novembre 2019) : 14403–15. http://dx.doi.org/10.5194/acp-19-14403-2019.

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Abstract. Secondary organic aerosol (SOA) formation from biogenic precursors is affected by anthropogenic emissions, which are not well understood in polluted areas. In this study, we accomplished a year-round campaign at nine sites in polluted areas located in the Pearl River Delta (PRD) region during 2015. We measured typical biogenic SOA (BSOA) tracers from isoprene, monoterpenes, and β-caryophyllene, as well as major gaseous and particulate pollutants and investigated the impact of anthropogenic pollutants on BSOA formation. The concentrations of BSOA tracers were in the range of 45.4 to 109 ng m−3 with the majority composed of products from monoterpenes (SOAM, 47.2±9.29 ng m−3), isoprene (SOAI, 23.1±10.8 ng m−3), and β-caryophyllene (SOAC, 3.85±1.75 ng m−3). We found that atmospheric oxidants, Ox (O3 plus NO2), and sulfate correlated well with later-generation SOAM tracers, but this was not the case for first-generation SOAM products. This suggested that high Ox and sulfate levels could promote the formation of later-generation SOAM products, which probably led to the relatively aged SOAM that we observed in the PRD. For the SOAI tracers, both 2-methylglyceric acid (NO/NO2-channel product) and the ratio of 2-methylglyceric acid to 2-methyltetrols (HO2-channel products) exhibit NOx dependence, indicating the significant impact of NOx on SOAI formation pathways. The SOAC tracer was elevated in winter at all sites and was positively correlated with levoglucosan, Ox, and sulfate. Thus, the unexpected increase in SOAC in wintertime might be highly associated with the enhancement of biomass burning, O3 chemistry, and the sulfate component in the PRD. The BSOAs that were estimated using the SOA tracer approach showed the highest concentration in fall and the lowest concentration in spring with an annual average concentration of 1.68±0.40 µg m−3. SOAM dominated the BSOA mass all year round. We also found that BSOA correlated well with sulfate and Ox. This implied a significant effect from anthropogenic pollutants on BSOA formation and highlighted that we could reduce BSOA by controlling the anthropogenic emissions of sulfate and Ox precursors in polluted regions.
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Zhao, D. F., A. Buchholz, B. Kortner, P. Schlag, F. Rubach, H. Fuchs, A. Kiendler-Scharr et al. « Cloud condensation nuclei activity, droplet growth kinetics and hygroscopicity of biogenic and anthropogenic Secondary Organic Aerosol (SOA) ». Atmospheric Chemistry and Physics Discussions 15, no 14 (21 juillet 2015) : 19903–45. http://dx.doi.org/10.5194/acpd-15-19903-2015.

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Abstract. Interaction of biogenic volatile organic compounds (VOC) with anthropogenic VOC affects the physicochemical properties of secondary organic aerosol (SOA). We investigated cloud droplet activation (CCN activity), droplet growth kinetics, and hygroscopicity of mixed anthropogenic and biogenic SOA (ABSOA) compared to pure biogenic SOA (BSOA) and pure anthropogenic SOA (ASOA). Selected monoterpenes and aromatics were used as representative precursors of BSOA and ASOA, respectively. We found that BSOA, ASOA, and ABSOA had similar CCN activity despite the higher oxygen to carbon ratio (O/C) of ASOA compared to BSOA and ABSOA. For individual reaction systems, CCN activity increased with the degree of oxidation. Yet, when considering all different types of SOA together, the hygroscopicity parameter, κCCN, did not correlate with O/C. Droplet growth kinetics of BSOA, ASOA, and ABSOA was comparable to that of (NH4)2SO4, which indicates that there was no delay in the water uptake for these SOA in supersaturated conditions. In contrast to CCN activity, the hygroscopicity parameter from hygroscopic tandem differential mobility analyzer (HTDMA) measurement, κHTDMA, of ASOA was distinctively higher (0.09–0.10) than that of BSOA (0.03–0.06), which was attributed to the higher degree of oxidation of ASOA. The ASOA components in mixed ABSOA enhanced aerosol hygroscopicity. Changing the ASOA fraction by adding BVOC to ASOA or vice versa AVOC to BSOA changed the hygroscopicity of aerosol, in line with the change in the degree of oxidation of aerosol. However, the hygroscopicity of ABSOA cannot be described by a simple linear combination of pure BSOA and ASOA systems. This indicates that additional processes, possibly oligomerization, affected the hygroscopicity. Closure analysis of CCN and HTDMA data showed κHTDMA was lower than κCCN by 30–70 %. Better closure was achieved for ASOA compared to BSOA. This discrepancy can be attributed to several reasons. ASOA seemed to have higher solubility in subsaturated conditions and/or higher surface tension at the activation point than that of BSOA.
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Zhao, D. F., A. Buchholz, B. Kortner, P. Schlag, F. Rubach, H. Fuchs, A. Kiendler-Scharr et al. « Cloud condensation nuclei activity, droplet growth kinetics, and hygroscopicity of biogenic and anthropogenic secondary organic aerosol (SOA) ». Atmospheric Chemistry and Physics 16, no 2 (1 février 2016) : 1105–21. http://dx.doi.org/10.5194/acp-16-1105-2016.

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Abstract. Interaction of biogenic volatile organic compounds (VOCs) with Anthropogenic VOC (AVOC) affects the physicochemical properties of secondary organic aerosol (SOA). We investigated cloud droplet activation (CCN activity), droplet growth kinetics, and hygroscopicity of mixed anthropogenic and biogenic SOA (ABSOA) compared to pure biogenic SOA (BSOA) and pure anthropogenic SOA (ASOA). Selected monoterpenes and aromatics were used as representative precursors of BSOA and ASOA, respectively.We found that BSOA, ASOA, and ABSOA had similar CCN activity despite the higher oxygen to carbon ratio (O/C) of ASOA compared to BSOA and ABSOA. For individual reaction systems, CCN activity increased with the degree of oxidation. Yet, when considering all different types of SOA together, the hygroscopicity parameter, κCCN, did not correlate with O/C. Droplet growth kinetics of BSOA, ASOA, and ABSOA were comparable to that of (NH4)2SO4, which indicates that there was no delay in the water uptake for these SOA in supersaturated conditions.In contrast to CCN activity, the hygroscopicity parameter from a hygroscopic tandem differential mobility analyzer (HTDMA) measurement, κHTDMA, of ASOA was distinctively higher (0.09–0.10) than that of BSOA (0.03–0.06), which was attributed to the higher degree of oxidation of ASOA. The ASOA components in mixed ABSOA enhanced aerosol hygroscopicity. Changing the ASOA fraction by adding biogenic VOC (BVOC) to ASOA or vice versa (AVOC to BSOA) changed the hygroscopicity of aerosol, in line with the change in the degree of oxidation of aerosol. However, the hygroscopicity of ABSOA cannot be described by a simple linear combination of pure BSOA and ASOA systems. This indicates that additional processes, possibly oligomerization, affected the hygroscopicity.Closure analysis of CCN and HTDMA data showed κHTDMA was lower than κCCN by 30–70 %. Better closure was achieved for ASOA compared to BSOA. This discrepancy can be attributed to several reasons. ASOA seemed to have higher solubility in subsaturated conditions and/or higher surface tension at the activation point than that of BSOA.
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Deng, Yange, Hikari Yai, Hiroaki Fujinari, Kaori Kawana, Tomoki Nakayama et Michihiro Mochida. « Diurnal variation and size dependence of the hygroscopicity of organic aerosol at a forest site in Wakayama, Japan : their relationship to CCN concentrations ». Atmospheric Chemistry and Physics 19, no 9 (6 mai 2019) : 5889–903. http://dx.doi.org/10.5194/acp-19-5889-2019.

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Abstract. Formation of biogenic secondary organic aerosol (BSOA) and its subsequent evolution can modify the hygroscopicity of the organic aerosol component (OA) in the forest atmosphere, and affect the concentrations of cloud condensation nuclei (CCN) there. In this study, size-resolved aerosol hygroscopic growth at 85 % relative humidity and size-resolved aerosol composition were measured using a hygroscopic tandem differential mobility analyzer and an aerosol mass spectrometer, respectively, at a forest site in Wakayama, Japan, in August and September 2015. The hygroscopicity parameter of OA (κorg) presented daily minima in the afternoon hours, and it also showed an increase with the increase in particle dry diameter. The magnitudes of the diurnal variations in κorg for particles with dry diameters of 100 and 300 nm were on average 0.091 and 0.096, respectively, and the difference in κorg between particles with dry diameters of 100 and 300 nm was on average 0.056. The relative contributions of the estimated fresh BSOA and regional OA to total OA could explain 40 % of the observed diurnal variations and size dependence of κorg. The hygroscopicity parameter of fresh BSOA was estimated to range from 0.089 to 0.12 for particles with dry diameters from 100 to 300 nm. Compared with the use of time- and size-resolved κorg, the use of time- and size-averaged κorg leads to under- and over-estimation of the fractional contribution of OA to CCN number concentrations in the range from −5.0 % to 26 %. This indicates that the diurnal variations and size dependence of κorg strongly affect the overall contribution of OA to CCN concentrations. The fractional contribution of fresh BSOA to CCN number concentrations could reach 0.28 during the period of intensive BSOA formation. The aging of the fresh BSOA, if it occurs, increases the estimated contribution of BSOA to CCN number concentrations by 52 %–84 %.
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Hong, Youwei, Xinbei Xu, Dan Liao, Taotao Liu, Xiaoting Ji, Ke Xu, Chunyang Liao, Ting Wang, Chunshui Lin et Jinsheng Chen. « Measurement report : Effects of anthropogenic emissions and environmental factors on the formation of biogenic secondary organic aerosol (BSOA) in a coastal city of southeastern China ». Atmospheric Chemistry and Physics 22, no 11 (16 juin 2022) : 7827–41. http://dx.doi.org/10.5194/acp-22-7827-2022.

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Abstract. To better understand the formation of biogenic secondary organic aerosol (BSOA), aerosol samples with a 4 h time resolution were collected during summer and winter in the southeast of China, along with online measurements of trace gases, aerosol chemical compositions, and meteorological parameters. The samples were analyzed by gas chromatography–mass spectrometry for PM2.5-bound secondary organic aerosol (SOA) tracers, including isoprene (SOAI), α/β-pinene (SOAM), β-caryophyllene (SOAC), and toluene (ASOA). The average concentrations of total SOA tracers in winter and summer were 38.8 and 111.9 ng m−3, respectively, with the predominance of SOAM (70.1 % and 45.8 %), followed by SOAI (14.0 % and 45.6 %), ASOA (11.0 % and 6.2 %) and SOAC (4.9 % and 2.3 %). Compared to those in winter, the majority of BSOA tracers in summer showed significant positive correlations with Ox (O3+NO2) (r = 0.443–0.808), HONO (r = 0.299–0.601), ultraviolet (UV) (r = 0.382–0.588) and temperature (T) (r = 0.529–0.852), indicating the influence of photochemical oxidation under relatively clean conditions. However, in winter, BSOA tracers were significantly correlated with PM2.5 (r = 0.407–0.867), NO3- (r = 0.416–0.884), SO42- (r = 0.419–0.813), and NH3 (r = 0.440–0.757), attributed to the contributions of anthropogenic emissions. Major BSOA tracers in both seasons were linearly correlated with aerosol acidity (pH) (r = 0.421–0.752), liquid water content (LWC) (r = 0.403–0.876) and SO42- (r = 0.419–0.813). The results indicated that acid-catalyzed reactive uptake onto sulfate aerosol particles enhanced the formation of BSOA. In summer, the clean air mass originated from the ocean, and chlorine depletion was observed. We also found that concentrations of the total SOA tracers were correlated with HCl (R2=0.545) and chlorine ions (r = 0.280–0.639) in PM2.5, reflecting the contribution of Cl-initiated volatile organic compound (VOC) oxidations to the formation of SOA. In winter, the northeast dominant wind direction brought continental polluted air mass to the monitoring site, affecting the transformation of BSOA tracers. This implied that anthropogenic emissions, atmospheric oxidation capacity and halogen chemistry have significant effects on the formation of BSOA in the southeast coastal area.
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Fang, Wenzheng, Lei Gong et Liusi Sheng. « Online analysis of secondary organic aerosols from OH-initiated photooxidation and ozonolysis of α-pinene, β-pinene, Δ3-carene and d-limonene by thermal desorption–photoionisation aerosol mass spectrometry ». Environmental Chemistry 14, no 2 (2017) : 75. http://dx.doi.org/10.1071/en16128.

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Environmental contextSecondary organic aerosol, formed by oxidation of volatile precursors such as monoterpenes, is a major contributor to the total atmospheric organic aerosol. We focus on the online mass spectrometric analysis of the aerosol generated by oxidation products of four major monoterpenes in an environmental chamber. Numerous important monoterpene oxidation products were clearly observed and provided a direct comparison of the formation of biogenic secondary organic aerosols. AbstractWe present here thermal desorption–tunable vacuum ultraviolet time-of-flight photoionisation aerosol mass spectrometry (TD-VUV-TOF-PIAMS) for online analysis of biogenic secondary organic aerosols (BSOAs) formed from OH-initiated photooxidation and dark ozonolysis of α-pinene, β-pinene, Δ3-carene and d-limonene in smog chamber experiments. The ‘soft’ ionisation at near-threshold photon energies (≤10.5eV) used in this study permits direct measurement of the fairly clean mass spectra, facilitating molecular identification. The online BSOA mass spectra compared well with previous offline measurements and most of the important monoterpene oxidation products were clearly found in the online mass spectra. Oxidation products such as monoterpene-derived acids (e.g. pinic acid, pinonic acid, 3-caronic acid, limononic acid, limonalic acid), ketones (e.g. norpinone, limonaketone), aldehydes (e.g. caronaldehyde, norcaronaldehyde, limononaldehyde) and multifunctional organics (e.g. hydroxypinonaldehydes, hydroxy-3-caronic aldehydes, hydroxylimononic acid) were tentatively identified. The online TD-VUV-TOF-PIAMS mass spectra showed that the OH-initiated photooxidation and ozonolysis of the same monoterpenes produced some similar BSOA products; for example, 3-caric acid, 3-caronic acid, 3-norcaronic acid, 3-norcaralic acid, caronaldehyde and norcaronaldehyde were observed in both photooxidation and ozonolysis of Δ3-carene. However, they could be formed through different pathways. Some of the same products and isomers (e.g. 10-oxopinonic acid, pinonic acid, norpinic acid, hydroxyl pinonaldehyde, norpinonic acid, norpinone) were formed during the photooxidation and ozonolysis of α-pinene and β-pinene. However, several different BSOA products were generated in these photooxidation and ozonolysis reactions due to their different parent structures. The OH–monoterpene reaction generated higher-molecular-weight products than O3–monoterpene owing to multiple OH additions to the unsaturated carbon bond. The online observation of key BSOA products provided a direct comparison of BSOA formation among different monoterpenes and insights into the formation pathways in the OH-initiated photooxidation and ozonolysis of monoterpenes.
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Li, J. J., G. H. Wang, J. J. Cao, X. M. Wang et R. J. Zhang. « Observation of biogenic secondary organic aerosols in the atmosphere of a mountain site in central China : temperature and relative humidity effects ». Atmospheric Chemistry and Physics 13, no 22 (28 novembre 2013) : 11535–49. http://dx.doi.org/10.5194/acp-13-11535-2013.

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Abstract. Secondary organic aerosols (SOA) derived from isoprene, pinene and caryophyllene were determined for PM10 and size-segregated (9-stages) aerosols collected at the summit (2060 m a.s.l.) of Mt. Hua, central China during the summer of 2009. Estimated concentrations of isoprene, α-/β-pinene and β-caryophyllene derived secondary organic carbon (SOC) are 81 ± 53, 29 ± 14 and 98 ± 53 ng m−3, accounting for 2.7 ± 1.0%, 0.8 ± 0.2% and 2.1 ± 1.0% of OC, respectively. Concentrations of biogenic (BSOA, the isoprene/pinene/caryophyllene oxidation products) and anthropogenic (ASOA, mainly aromatic acids) SOA positively correlated with temperature (R=0.57–0.90). However, a decreasing trend of BSOA concentration with an increase in relative humidity (RH) was observed during the sampling period, although a clear trend between ASOA and RH was not found. Based on the AIM Model calculation, we found that during the sampling period an increase in RH resulted in a decrease in the aerosol acidity and thus reduced the effect of acid-catalysis on BSOA formation. There was no significant correlation observed for the BSOA products and anthropogenic parameters (e.g. EC, SO42− and NO4−). Size distribution measurements showed that most of the determined BSOA are formed in the aerosol phase and enriched in the fine mode (<2.1 μm) except for cis-pinonic acid, which is formed in the gas phase and subsequently partitioned into aerosol phase and thus presents a bimodal pattern with a small peak in the fine mode and a large peak in the coarse mode (>2.1 μm).
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Thèses sur le sujet "BSOA"

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Hung, Jacky. « The Cystine Binding Protein (BspA) of Lactobacillus fermentum BR11 ». Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16146/1/Jacky_Hung_Thesis.pdf.

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BspA was first identified on the basis of being the major constituent of 5 M LiCl washes of whole Lactobacillus fermentum BR11 cells. The bspA gene is encoded within a putative ATP-binding cassette (ABC) transport operon, and sequence analysis revealed that it is a member of the family III solute binding proteins. Unlike the majority of solute binding proteins from Gram-positive bacteria, BspA is not tethered to a lipid anchor in the cell membrane, and hence is not a lipoprotein. Extraction of BspA with concentrated salt solutions such as 5 M LiCl is consistent with the notion that electrostatic interactions are responsible for securing it to the L. fermentum BR11 cell. L. fermentum PNG201 is a BspA negative mutant strain created by disrupting bspA. This strain was shown to be incapable of cystine uptake. Thus, the genetic and biochemical evidence strongly suggests BspA is a cystine binding protein of an ABC transporter. Measurement of the binding affinity between BspA and L-cystine has confirmed high affinity binding (dissociation constant is 0.2 µM), and high specificity (over 100-fold excess of non-target amino acids did not disrupt BspA / L-cystine binding). In addition, collagen did not appear to affect BspA/cystine binding, indicating extracellular matrix (ECM) binding capacity noted by other researchers may be unrelated to amino acid binding. An interesting phenotypic characteristic of L. fermentum PNG201 is its apparent increased sensitivity to oxygen and the superoxide-generating chemical - paraquat compared to the parent L. fermentum BR11 strain. Catalase supplemented aerobic cultures of L. fermentum BR11, and L. fermentum PNG201 were protected from oxidative stress, suggesting hydrogen peroxide is responsible for the observed oxidative stress. It was found that addition of cystine to aerobic cultures of L. fermentum BR11 or L. fermentum PNG201 protected both strains from oxidative stress, with L. fermentum BR11 able to utilize smaller concentrations of cystine compared to L. fermentum PNG201. Detection of hydrogen peroxide in aerobic cultures of L. fermentum BR11 and L. fermentum PNG201 confirmed the production of hydrogen peroxide is responsible for causing oxidative stress. The BspA mutant strain L. fermentum PNG201 consistently produced more hydrogen peroxide per optical density compared with the wild type, indicating it overproduced hydrogen peroxide. When 0.4 mM hydrogen peroxide has been accumulated by growing cell cultures, both L. fermentum BR11 and L. fermentum PNG201 enters stationary phase, suggesting both strains have a similar sensitivity to hydrogen peroxide. Small epitopes from the HIV gp41 protein and the Chlamydia psittaci major outer membrane protein have been successfully displayed on the cell surface of L. fermentum BR11 as fusion proteins to the BspA molecule. However, the capability of BspA in exporting larger polypeptides has not been tested. In this study, the large extracellular enzyme - glucosyltransferase (GtfJ) from Streptococcus salivarius ATCC 25975 was fused to BspA to demonstrate that this expression system is capable of exporting large functional enzymes to the cell surface of L. fermentum BR11. The native GtfJ is 160kDa in size and also contained an export signal, which was deleted in the cloning process and replaced with BspA, resulting in a fusion protein of 175kDa. Export of the BspA/GtfJ fusion protein is dependant entirely on BspA's export signal. Recombinant enzyme expression and glucosyltransferase activity were detected by measuring the glucan formed by sonicated cell extracts in acrylamide gels. Enzyme activity measurements on whole cells has revealed the recombinant Lactobacillus was incorporating 20-40 nmol of sucrose-derived-glucose into glucan per ml of cell culture per OD unit, which is comparable to activity levels exhibited by the native bacteria that expressed this enzyme. Comparison of GtfJ enzyme activity between whole cells and sonicated cell extracts of recombinant L. fermentum confirmed the extracellular location of BspA/GtfJ as enzyme activity was essentially identical.
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Hung, Jacky. « The Cystine Binding Protein (BspA) of Lactobacillus fermentum BR11 ». Queensland University of Technology, 2005. http://eprints.qut.edu.au/16146/.

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BspA was first identified on the basis of being the major constituent of 5 M LiCl washes of whole Lactobacillus fermentum BR11 cells. The bspA gene is encoded within a putative ATP-binding cassette (ABC) transport operon, and sequence analysis revealed that it is a member of the family III solute binding proteins. Unlike the majority of solute binding proteins from Gram-positive bacteria, BspA is not tethered to a lipid anchor in the cell membrane, and hence is not a lipoprotein. Extraction of BspA with concentrated salt solutions such as 5 M LiCl is consistent with the notion that electrostatic interactions are responsible for securing it to the L. fermentum BR11 cell. L. fermentum PNG201 is a BspA negative mutant strain created by disrupting bspA. This strain was shown to be incapable of cystine uptake. Thus, the genetic and biochemical evidence strongly suggests BspA is a cystine binding protein of an ABC transporter. Measurement of the binding affinity between BspA and L-cystine has confirmed high affinity binding (dissociation constant is 0.2 µM), and high specificity (over 100-fold excess of non-target amino acids did not disrupt BspA / L-cystine binding). In addition, collagen did not appear to affect BspA/cystine binding, indicating extracellular matrix (ECM) binding capacity noted by other researchers may be unrelated to amino acid binding. An interesting phenotypic characteristic of L. fermentum PNG201 is its apparent increased sensitivity to oxygen and the superoxide-generating chemical - paraquat compared to the parent L. fermentum BR11 strain. Catalase supplemented aerobic cultures of L. fermentum BR11, and L. fermentum PNG201 were protected from oxidative stress, suggesting hydrogen peroxide is responsible for the observed oxidative stress. It was found that addition of cystine to aerobic cultures of L. fermentum BR11 or L. fermentum PNG201 protected both strains from oxidative stress, with L. fermentum BR11 able to utilize smaller concentrations of cystine compared to L. fermentum PNG201. Detection of hydrogen peroxide in aerobic cultures of L. fermentum BR11 and L. fermentum PNG201 confirmed the production of hydrogen peroxide is responsible for causing oxidative stress. The BspA mutant strain L. fermentum PNG201 consistently produced more hydrogen peroxide per optical density compared with the wild type, indicating it overproduced hydrogen peroxide. When 0.4 mM hydrogen peroxide has been accumulated by growing cell cultures, both L. fermentum BR11 and L. fermentum PNG201 enters stationary phase, suggesting both strains have a similar sensitivity to hydrogen peroxide. Small epitopes from the HIV gp41 protein and the Chlamydia psittaci major outer membrane protein have been successfully displayed on the cell surface of L. fermentum BR11 as fusion proteins to the BspA molecule. However, the capability of BspA in exporting larger polypeptides has not been tested. In this study, the large extracellular enzyme - glucosyltransferase (GtfJ) from Streptococcus salivarius ATCC 25975 was fused to BspA to demonstrate that this expression system is capable of exporting large functional enzymes to the cell surface of L. fermentum BR11. The native GtfJ is 160kDa in size and also contained an export signal, which was deleted in the cloning process and replaced with BspA, resulting in a fusion protein of 175kDa. Export of the BspA/GtfJ fusion protein is dependant entirely on BspA's export signal. Recombinant enzyme expression and glucosyltransferase activity were detected by measuring the glucan formed by sonicated cell extracts in acrylamide gels. Enzyme activity measurements on whole cells has revealed the recombinant Lactobacillus was incorporating 20-40 nmol of sucrose-derived-glucose into glucan per ml of cell culture per OD unit, which is comparable to activity levels exhibited by the native bacteria that expressed this enzyme. Comparison of GtfJ enzyme activity between whole cells and sonicated cell extracts of recombinant L. fermentum confirmed the extracellular location of BspA/GtfJ as enzyme activity was essentially identical.
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Soutar, Colin. « Optical information processing using photorefractive BSO ». Thesis, Abertay University, 1991. https://rke.abertay.ac.uk/en/studentTheses/a757b4d3-6c1e-4600-aed8-430e7078c6c5.

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Several optical information processing tasks are implemented using photorefractive BSO as a dynamic holographic medium. The physical basis for the mechanism which allows the implementation of these devices is studied. The properties of BSO which make it particularly attractive as a processing medium are highlighted, and experimental results are presented to demonstrate its practical limitations. An extensive study is presented of the influence of optical bias on the grating formation characteristics. This leads to a documentation of the optimum conditions for transient enhancement of a beam diffracted from such a grating. This transient enhancement can be controlled to provide ideal characteristics for the implementation of transient devices such as a novelty filter. A novelty filter utilising this transient enhancement is subsequently demonstrated. It exhibits good temporal discrimination through the choice of suitable external optical conditions, and the use of digital thresholding. The overall device operates at T.V. frame rates. Results are also presented of various optical correlators using BSO. These include the optical intensity correlator. The unique properties of the intensity correlator are stressed by practical demonstration. Specifically, the relative intolerance of the intensity correlator (compared with coherent correlators) to the position of the various components is demonstrated. Also, the spatially incoherent readout light allows the use of a low-optical quality liquid crystal television (LCTV) as a low-cost spatial light modulator. Output results are then presented from the correlator using the LCTV as a dynamic readout device. This provides an updateable hologram as the reference of the correlator which is interrogated at frame rates by the LCTV. Finally, the temporal discrimination of the novelty filter is combined with the character recognition ability of the intensity correlator. This produces an optical processor which will recognise a particular object but will only register it at the output stage when it is moving.
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Cook, Nicholas James. « Properties and processing applications of photoreactive BSO ». Thesis, University of Abertay Dundee, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242115.

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Forsyth, Robert Bruce. « A study of auto-anti-idiotypes to BSA ». Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27425.

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In order to study the idiotypic relationships between the antibody populations produced in different species during normal immune responses to ordinary protein antigens, we raised immune sera in mice and chickens using three protein antigens: Bovine serum albumin (BSA), keyhole limpet hemocyanin (KLH) and diphtheria toxoid (DT). An avidin-biotin ELISA was used to measure idiotypic binding between antibody populations from these sera. We found that the chicken sera contained auto-anti-idiotypes (AAI) against antigen specific antibodies which were present in the same serum and which co-purified with those antibodies on antigen-sepharose columns. These AAI were present in secondary response chicken anti-BSA serum at levels comparable to that of the anti-BSA antibody. The chicken AAI also react specifically with Ids in mouse anti-BSA serum. Mouse anti-BSA serum completely inhibited the binding between the chicken Id and AAI. This similarity between the idiotypes of whole populations of antibodies produced in two distantly related species, in the absence of any manipulation with idiotypic or anti-idiotypic reagents, suggests that the AAI detected in this way are internal image antibodies. It indicates there is positive selection for such auto-anti-idiotypes to be internal images.
Science, Faculty of
Microbiology and Immunology, Department of
Graduate
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Wang, Zhao Qi. « Real-time optical intensity correlation using photorefractive BSO ». Thesis, Abertay University, 1995. https://rke.abertay.ac.uk/en/studentTheses/f1330975-bc23-4532-ac7b-8aeb9cad8c81.

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Real-time optical intensity correlation using a photorefractive BSO crystal and a liquid crystal television is implemented. The underlying physics basis is considered, some specific techniques to improve the operation are proposed, and several optical pattern recognition tasks are achieved. Photorefractive BSO is used as the holographic recording medium in the real-time intensity correlator. To improve the dynamic holographic recording, a moving grating technique is adopted. The nonlinear effects of moving gratings at large fringe modulation are experimentally investigated, and are compared with numerical predictions. Optical bias is adopted to overcome the difficulty of a large drop in the optimum fringe velocity with moving gratings. The effects of optical bias on the optimum fringe velocity and on the diffraction efficiency are studied. To overcome the inherent drawback of low discrimination of intensity correlation in optical pattern recognition, real-time edge-enhanced intensity correlation is achieved by means of nonlinear holographic recording in BSO. Real-time colour object recognition is achieved by using a commercially available and inexpensive colour liquid crystal television in the intensity correlator. Multi-class object recognition is achieved with a synthetic discriminant function filter displayed by the Epson liquid crystal display in the real-time intensity correlator. The phase and intensity modulation properties of the Epson liquid crystal display are studied. A further research topic which uses the Epson liquid crystal display to realize a newly designed spatial filter, the quantized amplitude-compensated matched filter, is proposed. The performance merits of the filter are investigated by means of computer simulations.
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Lin, Chenting. « Single crystal growth and characterization of BSO (Bi12SiO20) ». Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11647.

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Hecker, Dominic, Daniel Gloess, Peter Frach et Gerald Gerlach. « Electrospray ionization deposition of BSA under vacuum conditions ». SPIE, 2015. https://tud.qucosa.de/id/qucosa%3A35187.

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Vacuum deposition techniques like thermal evaporation and CVD with their precise layer control and high layer purity often cannot be applied for the deposition of chemical or biological molecules. The molecules are usually decomposed by heat. To overcome this problem, the Electrospray ionization (ESI) process known from mass spectroscopy is employed to transfer molecules into vacuum and to deposit them on a substrate. In this work, a homemade ESI tool was used to deposit BSA (Bovine serum albumin) layers with high deposition rates. Solutions with different concentrations of BSA were prepared using a methanol:water (MeOH:H2O) mixture (1:1) as solvent. The influence of the substrate distance on the deposition rate and on the transmission current was analyzed. Furthermore, the layer thickness distribution and layer adhesion were investigated.
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Kawamura, Keiichi. « BSO - Broad System of Ordering : an international bibliography ». K. Kawamura, 2011. http://hdl.handle.net/10150/129413.

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The book was originally prepared for publishing in print. The author has decided to make it available as an online edition
This bibliography,compiled by K. Kawamura, lists about 270 references to BSO ranging from 1973 to 2010. The number of languages covered in the bibliography is 19 in all: Arabic, Chinese, Croatian, Czech, Dutch, English, French, German, Hungarian, Italian, Japanese, Korean, Lithuanian, Polish, Portuguese, Russian, Slovak, Slovenian and Spanish. Every item has English abstract and/or annotation. Items are arranged in systematic order, and cross-references among related items as well as author and language indexes complement the systematic arrangement.
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Carvalho, Jesiel Freitas. « Crescimento e caracterização de monocristais fotorreativos : BSO e BTO ». Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-14012009-093345/.

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Neste trabalho crescemos monocristais de Bi12SiO20 (BSO) e de Bi12TiO20 (BTO). Os cristais de BSO foram crescidos pela técnica de Czochralski a partir da fase líquida com composição molar 6Bi2O3:1SiO2. Os melhores resultados foram obtidos para taxas de puxamento entre 1 e 2,5mm/h, a velocidade de rotação foi mantida constante em 20rpm. Os cristais de BTO foram crescidos pelo método top-seeded solution Growth (TSSG) a partir da composição molar 10Bi2O3:1SiO2, com taxas de puxamento menores que 0,3mm/h e velocidade de rotação entre 16 e 30 rpm. A qualidade dos cristais foi avaliada utilizando microscopia óptica e eletrônica, corrosão seletiva e raios-x. Por microscopia óptica identificamos os defeitos macroscópicos e discutimos sua natureza e possíveis causas. Utilizando a técnica de ataque químico seletivo, analisamos a morfologia das figuras de ataque e estimamos a densidade de deslocações. Visando identificar defeitos de estequiometria, fizemos medidas de composição por microanálise eletrônica. Para a caracterização cristalográfica, calculamos o parâmetro de rede por difração de raios-x usando o método do pó e confirmamos a estrutura cristalográfica através do método de Rietveld. E, ainda, medimos a atividade óptica que é uma constante característica dos cristais.
In this work we grew Bi12SiO20 (BSO) and Bi12TiO20 single crystals. The BSO crystals have been grown from the melt composition of 6Bi2O3:1SiO2 by the Czochralski method. The best results were obtained at pulling rates from 1 to 2.5m/h, the rotation rate of 20rpm was constant. The BTO crystals have been grown by the top-seeded solution growth technique from a 10Bi2O3:1SiO2 solution with pulling rates less than 0.3mm/h and rotation rates from 16 to 30rpm. The crystal quality was examined by optical and scanning electron microscopy, selective etching, and x-ray diffraction. We identified the macroscopic defects by optical microscopy and discussed their nature and probable origin. Using selective etching, we analyzed the etching pits morphology and evaluated the dislocation density. To identify stoichiometric defects, composition measurements by electron probe microanalysis were made. To obtain crystallographic characterization, we calculated the cell parameter by powder method x-ray diffraction and used the Rietveld method to verify the crystallographic structure. And, also, we measured the optical activity, a constant of the crystals.
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Livres sur le sujet "BSOA"

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BSO. Sevilla] : Ediciones En Huida, 2017.

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Bacon, Roy H. BSA. London : Sunburst, 1995.

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Appeals, Massachusetts Bureau of Special Education. BSEA hearing procedures. [Quincy, Mass.] : Massachusetts Board of Education, 1992.

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Association, British Science Fiction, dir. BSFA Awards 2008. London, UK : British Science Fiction Association, 2009.

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America, Boy Scouts of, dir. Scuba BSA. Irving, Tex : Boy Scouts of America, 2003.

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Wright, Owen. BSA M20 & M21. Sparkford, Nr. Yeovil, Somerset : Haynes Pub. Group, 1985.

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Hso, Trưxong An. Chuyuen ma đrat Tân Bsoi. Glendale, CA : Đại Nam, 1998.

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Vanhouse, Norman. BSA competition history. Sparkford, Nr. Yeovil, Somerset, England : Haynes Pub. Group, 1986.

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John, Gardner. BSA gold star. Sparkford, Nr., Yeovil, Somerset : Haynes Pub. Group, 1985.

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Association, British Show Jumping. BSJA Rules and year book 2001. Kenilworth : British Showjumping Association, 2001.

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Chapitres de livres sur le sujet "BSOA"

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Speer, Tod W., Rene Rubin, Iris Rusu, Iris Rusu, Yan Yu, Laura Doyle, Cheng B. Saw et al. « TAH-BSO ». Dans Encyclopedia of Radiation Oncology, 855. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-540-85516-3_1265.

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Makkar, Harinder P. S. « Radiolabelled BSA Precipitation Method ». Dans Quantification of Tannins in Tree and Shrub Foliage, 83–85. Dordrecht : Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-0273-7_12.

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Khalid, Lina. « Business Software Architecture (BSA) ». Dans Software Architecture for Business, 21–32. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-13632-1_2.

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Schmidt, Carolina Witchmichen Penteado. « Body Surface Area (BSA) ». Dans Pediatric Oncologic Pharmacy, 141. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10988-2_15.

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Blankenburg, Bastian, et Matthias Klusch. « BSCA-P : Privacy Preserving Coalition Formation ». Dans Multiagent System Technologies, 47–58. Berlin, Heidelberg : Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/11550648_5.

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Basu, Aviru Kumar, Amar Nath Sah, Asima Pradhan et Shantanu Bhattacharya. « BSA Detection on Polymeric Nanocantilever ». Dans Lecture Notes in Mechanical Engineering, 589–94. Singapore : Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6577-5_56.

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Doyle, D. John. « Estimated Body Surface Area (BSA) ». Dans Computer Programs in Clinical and Laboratory Medicine, 142–44. New York, NY : Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4612-3576-7_32.

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Makkar, Harinder P. S. « Simplified Radiolabelled BSA Precipitation Method ». Dans Quantification of Tannins in Tree and Shrub Foliage, 87–88. Dordrecht : Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-0273-7_13.

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Reddy, Narendra, et Yiqi Yang. « Regenerated Fibers from Bovine Serum Albumin (BSA) ». Dans Innovative Biofibers from Renewable Resources, 241–44. Berlin, Heidelberg : Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-45136-6_53.

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Mavropoulos, Elena, Nilce C. C. da Rocha, Maria Helena M. Rocha-Leão et Alexandre M. Rossi. « BSA Adsorption on Hydroxyapatite after Thermal Treatment ». Dans Bioceramics 20, 127–30. Stafa : Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-457-x.127.

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Actes de conférences sur le sujet "BSOA"

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Subbaraman, Raghav, Yeswanth Guntupalli, Shruti Jain, Rohit Kumar, Krishna Chintalapudi et Dinesh Bharadia. « BSMA ». Dans ACM MobiCom '22 : The 28th Annual International Conference on Mobile Computing and Networking. New York, NY, USA : ACM, 2022. http://dx.doi.org/10.1145/3495243.3560544.

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Klein, M. B., F. P. Strohkendl, B. A. Wechsler, G. A. Brost, J. E. Millerd et E. M. Garmire. « Large Signal Gain Effects in Photorefractive Bi12TiO20 at 633 nm ». Dans Photorefractive Materials, Effects, and Devices II. Washington, D.C. : Optica Publishing Group, 1991. http://dx.doi.org/10.1364/pmed.1991.tuc19.

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Bi12TiO20 (BTO) is a photorefractive material in the same structural class (sillenite) as Bi12SiO20 (BSO) and Bi12GiO20 (BGO). However, BTO offers some unique advantages over BSO and BGO: (1) larger electro-optic coefficient (5.7 pm/V)1, and (2) lower optical activity (6°/mm at 633 nm)1, 2. Previous photorefractive measurements3,4 have shown that gain coefficients on the order of 10-15 cm−1 can be produced through the use of an applied AC field. In this work we show that the largest gain values can only be obtained for large values of the pump/probe intensity ratio β. As β approaches unity (large signal regime), higher spatial order gratings become prominent, and the gain is reduced from its large-β value.5−8 Our results are similar to those obtained by other researchers for BSO5 and GaAs6 with an applied field. We have analyzed this and related phenomena using a finite difference method to model the photorefractive grating formation. This method yields accurate numerical solutions which are valid for for all values of β.
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Syms, Richard R. A. « BSOI MOEMS ». Dans MOEMS-MEMS Micro & Nanofabrication, sous la direction de Ayman El-Fatatry. SPIE, 2005. http://dx.doi.org/10.1117/12.600807.

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Vasconcelos, Gabriel S., Carlos A. C. M. Bastos, Tsang Ing Ren et George D. C. Cavalcanti. « BSOM network for pupil segmentation ». Dans 2011 International Joint Conference on Neural Networks (IJCNN 2011 - San Jose). IEEE, 2011. http://dx.doi.org/10.1109/ijcnn.2011.6033573.

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Dehghani, Mohammad, Zeinab Montazeri, Ali Dehghani, Nima Nouri et AliReza Seifi. « BSSA : Binary spring search algorithm ». Dans 2017 IEEE 4th International Conference on Knowledge-Based Engineering and Innovation (KBEI). IEEE, 2017. http://dx.doi.org/10.1109/kbei.2017.8324977.

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Au, L. B., L. Solymar et K. H. Ringhofer. « Subharmonics in BSO ». Dans Photorefractive Materials, Effects, and Devices II. Washington, D.C. : Optica Publishing Group, 1990. http://dx.doi.org/10.1364/pmed.1990.b4.

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In 1988, Mallick et al.[1] found self-generated subharmonics in Bi12SiO20 (BSO). They used two coherent almost linear pump beams (wave vectors k→ p and k→ p ′ , see Fig. 1) with grating vector K→ and frequency detuning Ω, impinging on a 1 cm thick BSO crystal. For a certain frequency detuning, they observed a third beam in the middle between the two pump beams with intensity as high as 40% of the pump beam intensity. The length of the grating vector for the grating written by one of the pump beams and the third beam was approximately K/2 and therefore they called the new beam a K/2-subharmonic.
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NANCE, THOMAS. « SENSING AND DATA ANALYTICS NEEDS TO ADVANCE AUTOMATION ». Dans BSRA UNIVERSITIES/ADVANCE MANUFACTORING CONFERENCE VIRTUAL FEB. 22-23, 2022. US DOE, 2022. http://dx.doi.org/10.2172/1855344.

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JAMES, RALPH. « BSRA COLLABORATION EXCHANGE ON ADVANCED MANUFACTURING ». Dans BSRA UNIVERSITIES/ADVANCE MANUFACTURING WORKSHOP CONFERENCE VIRTUAL FEBRUARY 22-23, 2022. US DOE, 2022. http://dx.doi.org/10.2172/1855346.

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BARNES, MARK. « CREATING MANUFACTURING SOLUTIONS FOR EM, NNSA, AND ENERGY SECURITY – ENERGY & ; ENVIRONMENT ». Dans BSRA UNIVERITIES/ADVANCE MANUFACTORING WORKSHOP CONFERENCE VIRTUAL FEBRUARY 22-23, 2022. US DOE, 2022. http://dx.doi.org/10.2172/1855345.

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Behague, F., F. Bassignot, L. Gauthier-Manuel, A. Caspar, V. Calero, F. Baida, M.-P. Bernal et N. Courjal. « Low-loss BSO photonic waveguides ». Dans Frontiers in Optics. Washington, D.C. : OSA, 2018. http://dx.doi.org/10.1364/fio.2018.jw3a.23.

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Rapports d'organisations sur le sujet "BSOA"

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Rabellotti, Roberta, et Elisa Conz. Mainstreaming the Cluster Approach in the Caribbean Region : The CCPF Cluster Capacity Building Initiative. Inter-American Development Bank, mars 2023. http://dx.doi.org/10.18235/0004771.

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In the Caribbean region, clusters hold tremendous potential because of the predominance of small and micro enterprises, their weak link in value chains and the scarcity of specialized inputs. The Compete Caribbean Partnership Facility (CCPF) has backed a capacity-building campaign for the cluster approach with the aim of mainstreaming cluster interventions in the region. This report explores how the process of mainstreaming is taking shape among those business support organizations (BSOs) involved in the CCPF project, currently involved in the implementation of cluster projects. The study addressed these questions: (i) Have the BSOs improved their capacity to identify, design, and implement sustainable cluster initiatives? (ii) Is the cluster approach becoming mainstream in the Caribbean region? Based on primary evidence, the main findings are as follows. BSOs have played a key role by engendering a collaborative culture amongst clusters. One of the main achievements in implementing cluster programs is the increasing cooperation between clusters. Among the BSOs, there is general agreement over the usefulness of monitoring the cluster implementation when taking informed decisions, but the collection of information is also challenging. In the Caribbean region, cluster policies do not yet represent the core of industrial development policies; nonetheless, the potential for a more regional approach to cluster mainstreaming has surfaced in interviews. Policy recommendations for introducing and promoting the mainstreaming of a cluster approach in the Caribbean region should take a three-pronged approach that focuses on (i) cluster organizations, (ii) national ecosystems, and (iii) regional ecosystems.
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Fisher, Alan. Expected Performance of the LHC Synchrotron-Light Telescope (BSRT) and Abort-Gap Monitor (BSRA). Office of Scientific and Technical Information (OSTI), juin 2010. http://dx.doi.org/10.2172/981694.

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Amzeri, Achmad, Kaswan Badami et Gita Pawana. Inheritance of resistance to downy mildew (Peronosclerospora maydis) in crossing of Madura Maize Plant (Zea mays L.). Innovative Scientific Information & Services Network, mai 2019. http://dx.doi.org/10.21107/amzeri.2019.1.

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Hybridization of Back cross is one method to get varieties that are resistant to downy mildew. The purpose of this study was to obtain information on inheritance characteristics of downy mildew resistance. This research was conducted at the experiment center of Agro-Technology Study Program of Agriculture Faculty, University of Trunojoyo Madura. Research of Assessment of resistance to Downy Mildew used a randomized block design with 18 treatments (P1, P2, F1, F2, BC1P1 and BC1P2 in three sets of crosses, namely LGL x Mdr-3, T12 x Mdr-1 and E02 x Mdr-2) and three replications so there were 54 experimental units. Identification of polymorphic RAPD markers for endurance to downy mildew through Bulk Segregant Analysis (BSA) was done by amplifying the DNA in the resistant pool and susceptible pool. The random primers used were 120 primers from 6 operon groups, namely OPA, OPB, OPC, OPD, OPF and OPG. The results showed that the inheritance pattern of maize genetic resistance to downy mildew followed a segregation pattern of 3:1 with a degree of dominance between -1 and 0, and was controlled by incomplete partially negative dominant gene. OPC-07 was a marker that was linkage close to the resistance to downy mildew with a genetic distance of 1.9 cM.
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Kanner, Joseph, Edwin Frankel, Stella Harel et Bruce German. Grapes, Wines and By-products as Potential Sources of Antioxidants. United States Department of Agriculture, janvier 1995. http://dx.doi.org/10.32747/1995.7568767.bard.

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Several grape varieties and red wines were found to contain large concentration of phenolic compounds which work as antioxidant in-vitro and in-vivo. Wastes from wine production contain antioxidants in large amounts, between 2-6% on dry material basis. Red wines but also white wines were found to prevent lipid peroxidation of turkey muscle tissues stored at 5oC. The antioxidant reaction of flavonoids found in red wines against lipid peroxidation were found to depend on the structure of the molecule. Red wine flavonoids containing an orthodihydroxy structure around the B ring were found highly active against LDL and membrane lipid peroxidation. The antioxidant activity of red wine polyphenols were also found to be dependent on the catalyzer used. In the presence of H2O2-activated myoglobin, the inhibition efficiency was malvidin 3-glucoside>catechin>malvidin>resveratol. However, in the presence of an iron redox cycle catalyzer, the order of effectiveness was resveratol>malvidin 3-glucoside = malvidin>catechin. Differences in protein binding were found to affect antioxidant activity in inhibiting LDL oxidation. A model protein such as BSA, was investigated on the antioxidant activity of phenolic compounds, grape extracts, and red wines in a lecithin-liposome model system. Ferulic acid followed by malvidin and rutin were the most efficient in inhibiting both lipid and protein oxidation. Catechin, a flavonal found in red-wines in relatively high concentration was found to inhibit myoglobin catalyzed linoleate membrane lipid peroxidation at a relatively very low concentration. This effect was studied by the determination of the by-products generated from linoleate during oxidation. The study showed that hydroperoxides are catalytically broken down, not to an alcohol but most probably to a non-radical adduct. The ability of wine-phenolics to reduce iron and from complexes with metals were also demonstrated. Low concentration of wine phenolics were found to inhibit lipoxygenase type II activity. An attempt to understand the bioavailability in humans of antocyanins from red wine showed that two antocyanins from red wine were found unchanged in human urine. Other antocyanins seems to undergo molecular modification. In hypercholesterolemic hamsters, aortic lipid deposition was significantly less in animals fed diets supplemented with either catechin or vitamin E. The rate of LDL accumulation in the carotid arteries was also significantly lower in the catechin and vitamin E animal groups. These results suggested a novel mechanism by which wine phenolics are associated with decreased risk of coronary heart diseases. This study proves in part our hypothesis that the "French Paradox" could be explained by the action of the antioxidant effects of phenolic compounds found at high concentration in red wines. The results of this study argue that it is in the interest of public health to increase the consumption of dietary plant falvonoids. Our results and these from others, show that the consumption of red wine or plant derived polyphenolics can change the antioxidant tone of animal and human plasma and its isolated components towards oxidative reactions. However, we need more research to better understand bioavailability and the mechanism of how polyphenolics affect health and disease.
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